Total heart volume as a function of clinical and anthropometric parameters in a population of external beam radiation therapy patients

NASA Astrophysics Data System (ADS)

Nadège Ilembe Badouna, Audrey; Veres, Cristina; Haddy, Nadia; Bidault, François; Lefkopoulos, Dimitri; Chavaudra, Jean; Bridier, André; de Vathaire, Florent; Diallo, Ibrahima

2012-01-01

The aim of this paper was to determine anthropometric parameters leading to the least uncertain estimate of heart size when connecting a computational phantom to an external beam radiation therapy (EBRT) patient. From computed tomography images, we segmented the heart and calculated its total volume (THV) in a population of 270 EBRT patients of both sexes, aged 0.7-83 years. Our data were fitted using logistic growth functions. The patient age, height, weight, body mass index and body surface area (BSA) were used as explanatory variables. For both genders, good fits were obtained with both weight (R2 = 0.89 for males and 0.83 for females) and BSA (R2 = 0.90 for males and 0.84 for females). These results demonstrate that, among anthropometric parameters, weight plays an important role in predicting THV. These findings should be taken into account when assigning a computational phantom to a patient.

Proposal of a new electromechanical total artificial heart: the TAH Serpentina.

PubMed

Sauer, I M; Frank, J; Bücherl, E S

1999-03-01

A new type of energy converter for an electro-mechanical total artificial heart (TAH) based on the principle of a unidirectional moving motor is described. Named the TAH Serpentina, the concept consists of 2 major parts, a pendulum shaped movable element fixed on one side using a joint bearing and a special shaped drum cam. Pusher plates are mounted flexibly to the crossbar of the pendulum. A motor drives the special shaped drum cam linked to the pendulum through a ball bearing. The circular motion of the unidirectional moving brushless DC motor is transferred into the linear motion of the pendulum to drive the pusher plates. Using a crossbar with a variable length, the stroke of the pendulum and therefore the displaced blood volume is alterable. To achieve a variable length, an electric driven screw thread or a hydraulic system is possible. Comparable to the natural heart, cardiac output would be determined by frequency and stroke volume.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirai, Katsuyuki, E-mail: katu.shirai@gmail.com; Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi; Tamaki, Yoshio

Purpose: To investigate the dose-volume histogram parameters and clinical factors as predictors of pleural effusion in esophageal cancer patients treated with concurrent chemoradiotherapy (CRT). Methods and Materials: Forty-three esophageal cancer patients treated with definitive CRT from January 2001 to March 2007 were reviewed retrospectively on the basis of the following criteria: pathologically confirmed esophageal cancer, available computed tomography scan for treatment planning, 6-month follow-up after CRT, and radiation dose {>=}50 Gy. Exclusion criteria were lung metastasis, malignant pleural effusion, and surgery. Mean heart dose, mean total lung dose, and percentages of heart or total lung volume receiving {>=}10-60 Gy (Heart-V{submore » 10} to V{sub 60} and Lung-V{sub 10} to V{sub 60}, respectively) were analyzed in relation to pleural effusion. Results: The median follow-up time was 26.9 months (range, 6.7-70.2) after CRT. Of the 43 patients, 15 (35%) developed pleural effusion. By univariate analysis, mean heart dose, Heart-V{sub 10} to V{sub 60}, and Lung-V{sub 50} to V{sub 60} were significantly associated with pleural effusion. Poor performance status, primary tumor of the distal esophagus, and age {>=}65 years were significantly related with pleural effusion. Multivariate analysis identified Heart-V{sub 50} as the strongest predictive factor for pleural effusion (p = 0.01). Patients with Heart-V{sub 50} <20%, 20%{<=} Heart-V{sub 50} <40%, and Heart-V{sub 50} {>=}40% had 6%, 44%, and 64% of pleural effusion, respectively (p < 0.01). Conclusion: Heart-V{sub 50} is a useful parameter for assessing the risk of pleural effusion and should be reduced to avoid pleural effusion.« less

Symptomatic radiation-induced cardiac disease in long-term survivors of esophageal cancer.

PubMed

Ogino, Ichiro; Watanabe, Shigenobu; Iwahashi, Noriaki; Kosuge, Masami; Sakamaki, Kentaro; Kunisaki, Chikara; Kimura, Kazuo

2016-06-01

To evaluate clinical and dosimetric factors retrospectively affecting the risk of symptomatic cardiac disease (SCD) in esophageal cancer patients treated with radiotherapy. A total of 343 patients with newly diagnosed esophageal cancer were managed with concurrent chemoradiotherapy or radiotherapy alone. Of these, 58 patients were followed at our hospital for at least 4 years. Median clinical follow-up was 79 months. Cardiac toxicity was determined by Common Terminology Criteria for Adverse Events (CTCAE) v. 4.0. The maximum and mean doses to the heart and percentage of the volume were calculated from the dose-volume histograms. SCD manifested in 11 patients. The heart diseases included three pericardial effusions, one pericardial effusion with valvular disease and paroxysmal atrial tachycardia, three atrial fibrillations, one sinus tachycardia, one coronary artery disease, one chest pain with strongly suspected coronary artery disease, and one congestive heart failure. The actual incidence of SCD was 13.8 % at 5 years. Univariate and multivariate analyses of continuous variables revealed that the risk of developing an SCD depended on the volume of the heart receiving a dose greater than 45 Gy (V45), 50 Gy (V50), and 55 Gy (V55). No other clinical factors were found to influence the risk of SCD. For V45, V50, and V55, the lowest significant cutoff values were 15, 10, and 5 %, respectively. High-dose and large-volume irradiation of the heart increased the risk of SCD in long-term survivors. Using modern radiotherapy techniques, it is important to minimize the heart dose-volume parameters without reducing the tumor dose.

Effect of captopril treatment on total and central vascular capacitance in dogs with chronic heart failure.

PubMed

Ogilvie, R I; Zborowska-Sluis, D

1994-09-01

Chronic rapid right ventricular pacing (RRVP) at 250 beats/min produces low cardiac output (CO) heart failure, marked reduction in total vascular capacitance, and a shift in volume centrally. The effect of converting enzyme inhibition with captopril on cardiac preload was investigated in this model of heart failure. Eight splenectomized dogs were treated with captopril (6.4 mg/kg daily) for 3 days before and 35 +/- 3 days (mean +/- SEM) after continuous RRVP was initiated and the outcome was compared with that of 5 untreated dogs subjected to RRVP for 32 +/- 3 days. Similar reductions in systemic arterial pressure (Psa) and CO and increases in right atrial pressure (Pra) and total peripheral resistance (TPR) were noted in both groups, however, pulmonary capillary wedge pressure (Ppcw) was higher in the untreated group (18.4 +/- 1.6 vs. 12.1 +/- 2.0 mm Hg). Total vascular compliance and capacitance was estimated from mean circulatory filling pressures (Pmcf) at different blood volumes (TBV) during transitory cardiac arrests with acetylcholine (ACh). Pmcf after chronic RRVP was higher in untreated animals (12.6 +/- 1.9 vs. 8.4 +/- 0.7 mm Hg) and compliance was lower (1.9 +/- 0.2 vs. 2.6 +/- 0.2 ml/mm Hg/kg). Total vascular capacitance at a Pmcf of 6 mm Hg was lower in untreated animals (50 +/- 6 vs. 68 +/- 3 ml/kg). Central vascular capacitance was also lower in untreated animals because Ppcw was higher and central blood volume (CBV) as a proportion of TBV was higher (21 +/- 3 vs. 15 +/- 2%). Four of 5 untreated and 1 of 8 treated dogs had severe ascites.(ABSTRACT TRUNCATED AT 250 WORDS)

Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

PubMed

Miller, Wayne L; Mullan, Brian P

2014-06-01

This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Auxiliary total artificial heart: A compact electromechanical artificial heart working simultaneously with the natural heart.

PubMed

Andrade, A; Nicolosi, D; Lucchi, J; Biscegli, J; Arruda, A C; Ohashi, Y; Mueller, J; Tayama, E; Glueck, J; Nosé, Y

1999-09-01

Leading international institutions are designing and developing various types of ventricular assist devices (VAD) and total artificial hearts (TAH). Some of the commercially available pulsatile VADs are not readily implantable into the thoracic cavity of smaller size patients because of size limitation. The majority of the TAH dimensions requires the removal of the patients' native heart. A miniaturized artificial heart, the auxiliary total artificial heart (ATAH), is being developed in these authors' laboratories. This device is an electromechanically driven ATAH using a brushless direct current (DC) motor fixed in a center metallic piece. This pusher plate-type ATAH control is based on Frank-Starling's law. The beating frequency is regulated through the change of the left preload, assisting the native heart in obtaining adequate blood flow. With the miniaturization of this pump, the average sized patient can have the surgical implantation procedure in the right thoracic cavity without removing the native heart. The left and right stroke volumes are 35 and 32 ml, respectively. In vitro tests were conducted, and the performance curves demonstrate that the ATAH produces 5 L/min of cardiac output at 180 bpm (10 mmHg of left inlet mean pressure and 100 mm Hg of left outlet mean pressure). Taking into account that this ATAH is working along with the native heart, this output is more than satisfactory for such a device.

A comparative analysis of 3D conformal deep inspiratory–breath hold and free-breathing intensity-modulated radiation therapy for left-sided breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reardon, Kelli A.; Read, Paul W.; Morris, Monica M.

2013-07-01

Patients undergoing radiation for left-sided breast cancer have increased rates of coronary artery disease. Free-breathing intensity-modulated radiation therapy (FB-IMRT) and 3-dimensional conformal deep inspiratory–breath hold (3D-DIBH) reduce cardiac irradiation. The purpose of this study is to compare the dose to organs at risk in FB-IMRT vs 3D-DIBH for patients with left-sided breast cancer. Ten patients with left-sided breast cancer had 2 computed tomography scans: free breathing and voluntary DIBH. Optimization of the IMRT plan was performed on the free-breathing scan using 6 noncoplanar tangential beams. The 3D-DIBH plan was optimized on the DIBH scan and used standard tangents. Mean volumesmore » of the heart, the left anterior descending coronary artery (LAD), the total lung, and the right breast receiving 5% to 95% (5% increments) of the prescription dose were calculated. Mean volumes of the heart and the LAD were lower (p<0.05) in 3D-DIBH for volumes receiving 5% to 80% of the prescription dose for the heart and 5% for the LAD. Mean dose to the LAD and heart were lower in 3D-DIBH (p≤0.01). Mean volumes of the total lung were lower in FB-IMRT for dose levels 20% to 75% (p<0.05), but mean dose was not different. Mean volumes of the right breast were not different for any dose; however, mean dose was lower for 3D-DIBH (p = 0.04). 3D-DIBH is an alternative approach to FB-IMRT that provides a clinically equivalent treatment for patients with left-sided breast cancer while sparing organs at risk with increased ease of implementation.« less

Interagency registry for mechanically assisted circulatory support report on the total artificial heart.

PubMed

Arabía, Francisco A; Cantor, Ryan S; Koehl, Devin A; Kasirajan, Vigneshwar; Gregoric, Igor; Moriguchi, Jaime D; Esmailian, Fardad; Ramzy, Danny; Chung, Joshua S; Czer, Lawrence S; Kobashigawa, Jon A; Smith, Richard G; Kirklin, James K

2018-04-26

We sought to better understand the patient population who receive a temporary total artificial heart (TAH) as bridge to transplant or as bridge to decision by evaluating data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database. We examined data related to survival, adverse events, and competing outcomes from patients who received TAHs between June 2006 and April 2017 and used hazard function analysis to explore risk factors for mortality. Data from 450 patients (87% men; mean age, 50 years) were available in the INTERMACS database. The 2 most common diagnoses were dilated cardiomyopathy (50%) and ischemic cardiomyopathy (20%). Risk factors for right heart failure were present in 82% of patients. Most patients were INTERMACS Profile 1 (43%) or 2 (37%) at implantation. There were 266 patients who eventually underwent transplantation, and 162 died. Overall 3-, 6-, and 12-month actuarial survival rates were 73%, 62%, and 53%, respectively. Risk factors for death included older age (p = 0.001), need for pre-implantation dialysis (p = 0.006), higher creatinine (p = 0.008) and lower albumin (p < 0.001) levels, and implantation at a low-volume center (≤10 TAHs; p < 0.001). Competing-outcomes analysis showed 71% of patients in high-volume centers were alive on the device or had undergone transplantation at 12 months after TAH implantation vs 57% in low-volume centers (p = 0.003). Patients receiving TAHs have rapidly declining cardiac function and require prompt intervention. Experienced centers have better outcomes, likely related to patient selection, timing of implantation, patient care, and device management. Organized transfer of knowledge to low-volume centers could improve outcomes. Copyright © 2018 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

An Inquiry-Based Teaching Tool for Understanding Arterial Blood Pressure Regulation and Cardiovascular Function.

ERIC Educational Resources Information Center

Collins, Heidi L.; Rodenbaugh, David W.; Murphy, Todd P.; Kulics, Jennifer M.; Bailey, Cynthia M.; DiCarlo, Stephen E.

1999-01-01

Presents a laboratory exercise designed to introduce students to the hemodynamic variables (heart rate, stroke volume, total peripheral resistance, and compliance) that alter arterial pressure. (Author/CCM)

Comparison of heart and coronary artery doses associated with intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy for distal esophageal cancer.

PubMed

Kole, Thomas P; Aghayere, Osarhieme; Kwah, Jason; Yorke, Ellen D; Goodman, Karyn A

2012-08-01

To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D-CRT. Long-term studies are necessary to determine how this will impact on development of coronary artery disease and other cardiac complications. Copyright © 2012 Elsevier Inc. All rights reserved.

Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer

PubMed Central

Ming, Xin; Feng, Yuanming; Liu, Huan; Zhang, Ying; Zhou, Li; Deng, Jun

2015-01-01

Purpose To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT), intensity-modulated radiotherapy (IMRT), or volumetric modulated arc therapy (VMAT) at our institution in the past seven years. Methods and Materials A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated. Results The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2%) with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance. Conclusions Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin’s disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy. PMID:26630566

Prototype Development of an Implantable Compliance Chamber for a Total Artificial Heart.

PubMed

Schmitz, Stephanie; Unthan, Kristin; Sedlaczek, Marc; Wald, Felix; Finocchiaro, Thomas; Spiliopoulos, Sotirios; Koerfer, Reiner; Steinseifer, Ulrich

2017-02-01

At our institute a total artificial heart is being developed. It is directly actuated by a linear drive in between two ventricles, which comprise membranes to separate the drive and blood flow. A compliance chamber (CC) is needed to reduce pressure peaks in the ventricles and to increase the pump capacity. Therefore, the movement of the membrane is supported by applying a negative pressure to the air volume inside the drive unit. This study presents the development of the implantable CC which is connected to the drive unit of the total artificial hearts (TAH). The anatomical fit of the CC is optimized by analyzing CT data and adapting the outer shape to ensure a proper fit. The pressure peaks are reduced by the additional volume and the flexible membrane of the CC. The validation measurements of change in pressure peaks and flow are performed using the complete TAH system connected to a custom mock circulation loop. Using the CC, the pressure peaks could be damped below 5 mm Hg in the operational range. The flow output was increased by up to 14.8% on the systemic side and 18.2% on the pulmonary side. The described implantable device can be used for upcoming chronic animal trials. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Gender differences in autonomic cardiovascular regulation: spectral, hormonal, and hemodynamic indexes

NASA Technical Reports Server (NTRS)

Evans, J. M.; Ziegler, M. G.; Patwardhan, A. R.; Ott, J. B.; Kim, C. S.; Leonelli, F. M.; Knapp, C. F.

2001-01-01

The autonomic nervous system drives variability in heart rate, vascular tone, cardiac ejection, and arterial pressure, but gender differences in autonomic regulation of the latter three parameters are not well documented. In addition to mean values, we used spectral analysis to calculate variability in arterial pressure, heart rate (R-R interval, RRI), stroke volume, and total peripheral resistance (TPR) and measured circulating levels of catecholamines and pancreatic polypeptide in two groups of 25 +/- 1.2-yr-old, healthy men and healthy follicular-phase women (40 total subjects, 10 men and 10 women per group). Group 1 subjects were studied supine, before and after beta- and muscarinic autonomic blockades, administered singly and together on separate days of study. Group 2 subjects were studied supine and drug free with the additional measurement of skin perfusion. In the unblocked state, we found that circulating levels of epinephrine and total spectral power of stroke volume, TPR, and skin perfusion ranged from two to six times greater in men than in women. The difference (men > women) in spectral power of TPR was maintained after beta- and muscarinic blockades, suggesting that the greater oscillations of vascular resistance in men may be alpha-adrenergically mediated. Men exhibited muscarinic buffering of mean TPR whereas women exhibited beta-adrenergic buffering of mean TPR as well as TPR and heart rate oscillations. Women had a greater distribution of RRI power in the breathing frequency range and a less negative slope of ln RRI power vs. ln frequency, both indicators that parasympathetic stimuli were the dominant influence on women's heart rate variability. The results of our study suggest a predominance of sympathetic vascular regulation in men compared with a dominant parasympathetic influence on heart rate regulation in women.

Echocardiographic measurements of left ventricular mass by a non-geometric method

NASA Technical Reports Server (NTRS)

Parra, Beatriz; Buckey, Jay; Degraff, David; Gaffney, F. Andrew; Blomqvist, C. Gunnar

1987-01-01

The accuracy of a new nongeometric method for calculating left ventricular myocardial volumes from two-dimensional echocardiographic images was assessed in vitro using 20 formalin-fixed normal human hearts. Serial oblique short-axis images were acquired from one point at 5-deg intervals, for a total of 10-12 cross sections. Echocardiographic myocardial volumes were calculated as the difference between the volumes defined by the epi- and endocardial surfaces. Actual myocardial volumes were determined by water displacement. Volumes ranged from 80 to 174 ml (mean 130.8 ml). Linear regression analysis demonstrated excellent agreement between the echocardiographic and direct measurements.

A Prospective Study of the Use of Fetal Intelligent Navigation Echocardiography (FINE) to Obtain Standard Fetal Echocardiography Views

PubMed Central

Veronese, Paola; Bogana, Gianna; Cerutti, Alessia; Yeo, Lami; Romero, Roberto; Gervasi, Maria Teresa

2016-01-01

Objective To evaluate the performance of Fetal Intelligent Navigation Echocardiography (FINE) applied to spatiotemporal image correlation (STIC) volume datasets of the normal fetal heart in generating standard fetal echocardiography views. Methods In this prospective cohort study of patients with normal fetal hearts (19-30 gestational weeks), one or more STIC volume datasets were obtained of the apical four-chamber view. Each STIC volume successfully obtained was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates for standard fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated. Results One or more STIC volumes (n=463 total) were obtained in 246 patients. A single STIC volume per patient was analyzed using the FINE method. In normal cases, FINE was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 76-100% of cases; 2) VIS-Assistance® in 96-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 96-100% of cases. Conclusion FINE applied to STIC volumes can successfully generate nine standard fetal echocardiography views in 96-100% of cases in the second and third trimesters. This suggests that the technology can be used as a method to screen for congenital heart disease. PMID:27309391

Trends in Coronary Revascularization and Ischemic Heart Disease-Related Mortality in Israel.

PubMed

Blumenfeld, Orit; Na'amnih, Wasef; Shapira-Daniels, Ayelet; Lotan, Chaim; Shohat, Tamy; Shapira, Oz M

2017-02-17

We investigated national trends in volume and outcomes of percutaneous coronary angioplasty (PCI), coronary artery bypass grafting (CABG), and ischemic heart disease-related mortality in Israel. Using International Classification of Diseases 9th and 10th revision codes, we linked 5 Israeli national databases, including the Israel Center for Disease Control National PCI and CABG Registries, the Ministry of Health Hospitalization Report, the Center of Bureau of Statistics, and the Ministry of Interior Mortality Report, to assess the annual PCI and CABG volume, procedural mortality, comorbidities, and ischemic heart disease-related mortality between 2002 and 2014. Trends over time were analyzed using linear regression, assuming a Poisson distribution. A total of 298 390 revascularization procedures (PCI: 255 724, CABG: 42 666) were performed during the study period. PCI volume increased by 9% from 2002 to 2008 (387.4/100 000 to 423.2/100 000), steadily decreasing by 10.5% to 378.5/100 000 in 2014 ( P =0.70 for the trend). CABG volume decreased by 59% (109.0/100 000 to 45.2/100 000) from 2002 to 2013, leveling at 46.4/100 000 ( P <0.0001). PCI/CABG ratio increased from 3.6 in 2002 to 8.5 in 2013, slightly decreasing to 8.2 by 2014 ( P <0.0001). In-hospital procedural mortality remained stable (PCI: 1.2-1.6%, P =0.34, CABG: 3.7-4.4%, P =0.29) despite a significant change in patient clinical profile. During the course of the study, ischemic heart disease-related mortality decreased by 46% (84.6-46/100 000, P <0.001). We observed a dramatic change in coronary revascularization procedures type and volume, and a marked decrease in ischemic heart disease-related mortality in Israel. The reasons for the observed changes remain unclear and need to be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Feasibility and reliability of pocket-size ultrasound examinations of the pleural cavities and vena cava inferior performed by nurses in an outpatient heart failure clinic.

PubMed

Dalen, Havard; Gundersen, Guri H; Skjetne, Kyrre; Haug, Hilde H; Kleinau, Jens O; Norekval, Tone M; Graven, Torbjorn

2015-08-01

Routine assessment of volume state by ultrasound may improve follow-up of heart failure patients. We aimed to study the feasibility and reliability of focused pocket-size ultrasound examinations of the pleural cavities and the inferior vena cava performed by nurses to assess volume state at an outpatient heart failure clinic. Ultrasound examinations were performed in 62 included heart failure patients by specialized nurses with a pocket-size imaging device (PSID). Patients were then re-examined by a cardiologist with a high-end scanner for reference within 1 h. Specialized nurses were able to obtain and interpret images from both pleural cavities and the inferior vena cava and estimate the volume status in all patients. Time consumption for focused ultrasound examination was median 5 min. In total 26 patients had any kind of pleural effusion (in 39 pleural cavities) by reference. The sensitivity, specificity, positive and negative predictive values were high, all ≥ 92%. The correlations with reference were high for all measurements, all r ≥ 0.79. Coefficients of variation for end-expiratory dimension of inferior vena cava and quantification of pleural effusion were 10.8% and 12.7%, respectively. Specialized nurses were, after a dedicated training protocol, able to obtain reliable recordings of both pleural cavities and the inferior vena cava by PSID and interpret the images in a reliable way. Implementing focused ultrasound examinations to assess volume status by nurses in an outpatient heart failure clinic may improve diagnostics, and thus improve therapy. © The European Society of Cardiology 2014.

Dosimetric comparison of normal structures associated with accelerated partial breast irradiation and whole breast irradiation delivered by intensity modulated radiotherapy for early breast cancer after breast conserving surgery.

PubMed

Wu, S; He, Z; Guo, J; Li, F; Lin, Q; Guan, X

2014-01-01

To assess the heart and lung dosimetry results associated with accelerated partial breast irradiation intensity-modulated radiotherapy (APBI-IMRT) and whole breast field-in-field intensity-modulated radiotherapy (WBI-FIF-IMRT). A total of 29 patients with early-stage breast cancer after lumpectomy were included in this study. APBI-IMRT and WBI-FIF-IMRT plans were generated for each patient. The dosimetric parameters of ipsilateral lung and heart in both plans were then compared with and without radiobiological correction. With and without radiobiological correction, the volume of ipsilateral lung showed a substantially lower radiation exposure in APBI-IMRT with moderate to high doses (P < 0.05) but non-significant increases in volume of ipsilateral lung in 2.5 Gy than WBI-FIF-IMRT (P > 0.905).There was no significant difference in volume of ipsilateral lung receiving 1, 2.5, and 5 Gy between APBI-IMRT and WBI (P > 0.05) in patients with medial tumor location, although APBI-IMRT exposed more lung to 2.5 and 5 Gy. APBI-IMRT significantly decreases the volume of heart receiving low to high doses in left-sided breast cancer (P < 0.05). APBI-IMRT can significantly spare the volume of heart and ipsilateral lung receiving moderate and high dose. Non-significant increases in volume of the ipsilateral lung exposed to low doses of radiation were observed for APBI-IMRT in comparison to WBI-FIF-IMRT, particularly in patients with medial tumor location. With the increasing interest in APBI-IMRT, our data may help clinicians individualize patient treatment decisions.

Bilateral implant reconstruction does not affect the quality of postmastectomy radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Alice Y., E-mail: hoa1234@mskcc.org; Patel, Nisha; Ohri, Nisha

To determine if the presence of bilateral implants, in addition to other anatomic and treatment-related variables, affects coverage of the target volume and dose to the heart and lung in patients receiving postmastectomy radiation therapy (PMRT). A total of 197 consecutive women with breast cancer underwent mastectomy and immediate tissue expander (TE) placement, with or without exchange for a permanent implant (PI) before radiation therapy at our center. PMRT was delivered with 2 tangential beams + supraclavicular lymph node field (50 Gy). Patients were grouped by implant number: 51% unilateral (100) and 49% bilateral (97). The planning target volume (PTV)more » (defined as implant + chest wall + nodes), heart, and ipsilateral lung were contoured and the following parameters were abstracted from dose-volume histogram (DVH) data: PTV D{sub 95%} > 98%, Lung V{sub 20}Gy > 30%, and Heart V{sub 25}Gy > 5%. Univariate (UVA) and multivariate analyses (MVA) were performed to determine the association of variables with these parameters. The 2 groups were well balanced for implant type and volume, internal mammary node (IMN) treatment, and laterality. In the entire cohort, 90% had PTV D{sub 95%} > 98%, indicating excellent coverage of the chest wall. Of the patients, 27% had high lung doses (V{sub 20}Gy > 30%) and 16% had high heart doses (V{sub 25}Gy > 5%). No significant factors were associated with suboptimal PTV coverage. On MVA, IMN treatment was found to be highly associated with high lung and heart doses (both p < 0.0001), but implant number was not (p = 0.54). In patients with bilateral implants, IMN treatment was the only predictor of dose to the contralateral implant (p = 0.001). In conclusion, bilateral implants do not compromise coverage of the target volume or increase lung and heart dose in patients receiving PMRT. The most important predictor of high lung and heart doses in patients with implant-based reconstruction, whether unilateral or bilateral, is treatment of the IMNs. Refinement of radiation techniques in reconstructed patients who require comprehensive nodal irradiation is warranted.« less

Dynamic heart model for the mathematical cardiac torso (MCAT) phantom to represent the invariant total heart volume

NASA Astrophysics Data System (ADS)

Pretorius, P. H.; King, Michael A.; Tsui, Benjamin M.; LaCroix, Karen; Xia, Weishi

1998-07-01

This manuscript documents the alteration of the heart model of the MCAT phantom to better represent cardiac motion. The objective of the inclusion of motion was to develop a digital simulation of the heart such that the impact of cardiac motion on single photon emission computed tomography (SPECT) imaging could be assessed and methods of quantitating cardiac function could be investigated. The motion of the dynamic MCAT's heart is modeled by a 128 time frame volume curve. Eight time frames are averaged together to obtain a gated perfusion acquisition of 16 time frames and ensure motion within every time frame. The position of the MCAT heart was changed during contraction to rotate back and forth around the long axis through the center of the left ventricle (LV) using the end systolic time frame as turning point. Simple respiratory motion was also introduced by changing the orientation of the heart model in a 2 dimensional (2D) plane with every time frame. The averaging effect of respiratory motion in a specific time frame was modeled by randomly selecting multiple heart locations between two extreme orientations. Non-gated perfusion phantoms were also generated by averaging over all time frames. Maximal chamber volumes were selected to fit a profile of a normal healthy person. These volumes were changed during contraction of the ventricles such that the increase in volume in the atria compensated for the decrease in volume in the ventricles. The myocardium were modeled to represent shortening of muscle fibers during contraction with the base of the ventricles moving towards a static apex. The apical region was modeled with moderate wall thinning present while myocardial mass was conserved. To test the applicability of the dynamic heart model, myocardial wall thickening was measured using maximum counts and full width half maximum measurements, and compared with published trends. An analytical 3D projector, with attenuation and detector response included, was used to generate radionuclide projection data sets. After reconstruction a linear relationship was obtained between maximum myocardial counts and myocardium thickness, similar to published results. A numeric difference in values from different locations exist due to different amounts of attenuation present. Similar results were obtained for FWHM measurements. Also, a hot apical region on the polar maps without attenuation compensation turns into an apical defect with attenuation compensation. The apical decrease was more prominent in ED than ES due to the change in the partial volume effect. Both of these agree with clinical trends. It is concluded that the dynamic MCAT (dMCAT) phantom can be used to study the influence of various physical parameters on radionuclide perfusion imaging.

Chemohypersensitivity and autonomic modulation of venous capacitance in the pathophysiology of acute decompensated heart failure.

PubMed

Burchell, Amy E; Sobotka, Paul A; Hart, Emma C; Nightingale, Angus K; Dunlap, Mark E

2013-06-01

Heart failure is increasing in prevalence around the world, with hospitalization and re-hospitalization as a result of acute decompensated heart failure (ADHF) presenting a huge social and economic burden. The mechanism for this decompensation is not clear. Whilst in some cases it is due to volume expansion, over half of patients with an acute admission for ADHF did not experience an increase in total body weight. This calls into question the current treatment strategy of targeting salt and water retention in ADHF. An alternative hypothesis proposed by Fallick et al. is that an endogenous fluid shift from the splanchnic bed is implicated in ADHF, rather than an exogenous fluid gain. The hypothesis states further that this shift is triggered by an increase in sympathetic tone causing vasoconstriction in the splanchnic bed, a mechanism that can translocate blood rapidly into the effective circulating volume, generating the raised venous pressure and congestion seen in ADHF. This hypothesis encourages a new clinical paradigm which focuses on the underlying mechanisms of congestion, and highlights the importance of fluid redistribution and neurohormonal activation in its pathophysiology. In this article, we consider the concept that ADHF is attributable to episodic sympathetic hyperactivity, resulting in fluid shifts from the splanchnic bed. Chemosensitivity is a pathologic autonomic mechanism associated with mortality in patients with systolic heart failure. Tonic and episodic activity of the peripheral chemoreceptors may underlie the syndrome of acute decompensation without total body salt and water expansion. We suggest in this manuscript that chemosensitivity in response to intermittent hypoxia, such as experienced in sleep disordered breathing, may explain the intermittent sympathetic hyperactivity underlying renal sodium retention and acute volume redistribution from venous storage sites. This hypothesis provides an alternative structure to guide novel diagnostic and treatment strategies for ADHF.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kole, Thomas P.; Aghayere, Osarhieme; Kwah, Jason

Purpose: To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Methods and Materials: Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters weremore » statistically evaluated using the Wilcoxon rank-sum test. Results: Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Conclusions: Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D-CRT. Long-term studies are necessary to determine how this will impact on development of coronary artery disease and other cardiac complications.« less

Minimal role of nitric oxide in basal coronary flow regulation and cardiac energetics of blood-perfused isolated canine heart.

PubMed Central

Saeki, A; Recchia, F A; Senzaki, H; Kass, D A

1996-01-01

1. The role of nitric oxide (NO) in the regulation of basal coronary perfusion and ventricular chamber energetics was studied in isovolumetrically contracting isolated blood-perfused canine hearts. Hearts were cross-perfused by a donor animal prior to isolation, and chamber volume controlled by a servo-pump. Coronary sinus flow and arterial-coronary sinus oxygen difference were measured to determine energetic efficiency. 2. NO synthase (NOS) was competitively inhibited by NG-monomethyl-L-arginine (L-NMMA; 0.5 mg kg-1, intracoronary), resulting in a reduction of acetylcholine (50 micrograms min-1)-induced flow augmentation from 143 to 62% (P < 0.001). 3. NOS inhibition had no significant effect on basal coronary flow. Coronary pressure-flow relationships were determined at a constant cardiac workload by varying mean perfusion pressure between 20 and 150 mmHg. Neither the shape of the relationship, nor the low-pressure value at which flow regulation was substantially diminished were altered by NOS inhibition. 4. Myocardial efficiency was assessed by the relationship between myocardial oxygen consumption and total pressure-volume area (PVA), with cavity volume altered to generate varying PVAs. This relative load-independent measure of energetic efficiency was minimally altered by NOS inhibition. 5. These results contrast with isolated crystalloid-perfused heart experiments and suggest that in hearts with highly controlled ventricular loading and whole-blood perfusion, effects of basal NO production on coronary perfusion and left ventricular energetics are minimal. PMID:8866868

Associations of coronary artery calcified plaque density with mortality in type 2 diabetes: the Diabetes Heart Study.

PubMed

Raffield, Laura M; Cox, Amanda J; Criqui, Michael H; Hsu, Fang-Chi; Terry, James G; Xu, Jianzhao; Freedman, Barry I; Carr, J Jeffrey; Bowden, Donald W

2018-05-11

Coronary artery calcified plaque (CAC) is strongly predictive of cardiovascular disease (CVD) events and mortality, both in general populations and individuals with type 2 diabetes at high risk for CVD. CAC is typically reported as an Agatston score, which is weighted for increased plaque density. However, the role of CAC density in CVD risk prediction, independently and with CAC volume, remains unclear. We examined the role of CAC density in individuals with type 2 diabetes from the family-based Diabetes Heart Study and the African American-Diabetes Heart Study. CAC density was calculated as mass divided by volume, and associations with incident all-cause and CVD mortality [median follow-up 10.2 years European Americans (n = 902, n = 286 deceased), 5.2 years African Americans (n = 552, n = 93 deceased)] were examined using Cox proportional hazards models, independently and in models adjusted for CAC volume. In European Americans, CAC density, like Agatston score and volume, was consistently associated with increased risk of all-cause and CVD mortality (p ≤ 0.002) in models adjusted for age, sex, statin use, total cholesterol, HDL, systolic blood pressure, high blood pressure medication use, and current smoking. However, these associations were no longer significant when models were additionally adjusted for CAC volume. CAC density was not significantly associated with mortality, either alone or adjusted for CAC volume, in African Americans. CAC density is not associated with mortality independent from CAC volume in European Americans and African Americans with type 2 diabetes.

Effects of heart rate on experimentally produced mitral regurgitation in dogs.

PubMed

Yoran, C; Yellin, E L; Hori, M; Tsujioka, K; Laniado, S; Sonnenblick, E H; Frater, R W

1983-12-01

The effects of increasing heart rate (HR) on the hemodynamics of acute mitral regurgitation (MR) were studied in 8 open-chest dogs. Filling volume, regurgitant volume and stroke volume were calculated from electromagnetic probe measurements of mitral and aortic flows. The left atrial-left ventricular systolic pressure gradient was measured with micromanometers. The calculated effective mitral regurgitant orifice area varied from 10 to 128 mm2, with a consequent regurgitant fraction (regurgitant volume/filling volume) of 24 to 62%. After crushing the sinus node, HR was increased stepwise from 90 to 180 beats/min by atrial pacing while maintaining aortic pressure constant. With increasing HR, filling volume, stroke volume, regurgitant volume and regurgitant time decreased; total cardiac output, forward cardiac output, regurgitant output, systolic pressure gradient, regurgitant fraction and the regurgitant orifice did not change; left ventricular end-diastolic pressure decreased; and left atrial v-wave amplitude increased. These results indicate that in acute experimental MR with a wide spectrum of incompetence, the relative distribution of forward and regurgitant flows did not change with large increases in HR. At rates greater than 150 beats/min the atrial contraction occurs early and increases the amplitude of the left atrial v wave. This may contribute to the severity of pulmonary congestion in patients with MR.

Forensic postmortem computed tomography: volumetric measurement of the heart and liver.

PubMed

Jakobsen, Lykke Schrøder; Lundemose, Sissel; Banner, Jytte; Lynnerup, Niels; Jacobsen, Christina

2016-12-01

The purpose of this study was to investigate the utility of postmortem computed tomography (PMCT) images in estimating organ sizes and to examine the use of the cardiothoracic ratio (CTR). We included 45 individuals (19 females), who underwent a medico-legal autopsy. Using the computer software program Mimics ® , we determined in situ heart and liver volumes derived from linear measurements (width, height and depth) on a whole body PMCT-scan, and compared the volumes with ex vivo volumes derived by CT-scan of the eviscerated heart and liver. The ex vivo volumes were also compared with the organ weights. Further, we compared the CTR with the ex vivo heart volume and a heart weight-ratio (HWR). Intra- and inter-observer analyses were performed. We found no correlation between the in situ and ex vivo volumes of the heart and liver. However, a highly significant correlation was found between the ex vivo volumes and weights of the heart and liver. No correlations between CTR and the ex vivo heart volume nor with HWR was found. Concerning cardiomegaly, we found no agreement between the CTR and HWR. The intra- and inter-observer analyses showed no significant differences. Noninvasive in situ PMCT methods for organ measuring, as performed in this study, are not useful tools in forensic pathology. The best method to estimate organ volume is a CT-scan of the eviscerated organ. PMCT-determined CTR seems to be useless for ascertaining cardiomegaly, as it neither correlated with the ex vivo heart volume nor with the HWR.

Elementary theory of synchronous arterio-arterial blood pumps

NASA Technical Reports Server (NTRS)

Jones, R. T.; Petscheck, H. E.; Kantrowitz, A. R.

1976-01-01

In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by a formula that considers stroke output of the unaided heart and the increment caused by the pump with a stroke. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological mechanical impedance of the heart. The total effect is, however, independent of the impedance.

Physiological characterization of the SynCardia total artificial heart in a mock circulation system.

PubMed

Crosby, Jessica R; DeCook, Katrina J; Tran, Phat L; Smith, Richard G; Larson, Douglas F; Khalpey, Zain I; Burkhoff, Daniel; Slepian, Marvin J

2015-01-01

The SynCardia total artificial heart (TAH) has emerged as an effective, life-saving biventricular replacement system for a wide variety of patients with end-stage heart failure. Although the clinical performance of the TAH is established, modern physiological characterization, in terms of elastance behavior and pressure-volume (PV) characterization has not been defined. Herein, we examine the TAH in terms of elastance using a nonejecting left ventricle, and then characterize the PV relation of the TAH by varying preload and afterload parameters using a Donovan Mock Circulatory System. We demonstrate that the TAH does not operate with time-varying elastance, differing from the human heart. Furthermore, we show that the TAH has a PV relation behavior that also differs from that of the human heart. The TAH does exhibit Starling-like behavior, with output increasing via preload-dependent mechanisms, without reliance on an alteration of inotropic state within the operating window of the TAH. Within our testing range, the TAH is insensitive to variations in afterload; however, this insensitivity has a limit, the limit being the maximum driving pressure of the pneumatic driver. Understanding the physiology of the TAH affords insight into the functional parameters that govern artificial heart behavior providing perspective on differences compared with the human heart.

Regional Microstructural and Volumetric Magnetic Resonance Imaging (MRI) Abnormalities in the Corpus Callosum of Neonates With Congenital Heart Defect Undergoing Cardiac Surgery.

PubMed

Hagmann, Cornelia; Singer, Jitka; Latal, Beatrice; Knirsch, Walter; Makki, Malek

2016-03-01

The purpose of the study is to investigate the structural development of the corpus callosum in term neonates with congenital heart defect before and after surgery using diffusion tensor imaging and 3-dimensional T1-weighted magnetic resonance imaging (MRI). We compared parallel and radial diffusions, apparent diffusion coefficient (ADC), fractional anisotropy, and volume of 5 substructures of the corpus callosum: genu, rostral body, body, isthmus, and splenium. Compared to healthy controls, we found a significantly lower volume of the splenium and total corpus callosum and a higher radial diffusion and lower fractional anisotropy in the splenium of patients presurgery; a lower volume in all substructures in the postsurgery group; higher radial diffusion in the rostral body, body, and splenium; and a higher apparent diffusion coefficient in the splenium of postsurgery patients. Similar fractional anisotropy changes in congenital heart defect patients were reported in preterm infants. Our findings in apparent diffusion coefficient in the splenium of these patients (pre and postsurgery) are comparable to findings in preterm neonates with psychomotor delay. Delayed maturation of the isthmus was also reported in preterm infants. © The Author(s) 2015.

Predictive factors for pericardial effusion identified by heart dose-volume histogram analysis in oesophageal cancer patients treated with chemoradiotherapy.

PubMed

Hayashi, K; Fujiwara, Y; Nomura, M; Kamata, M; Kojima, H; Kohzai, M; Sumita, K; Tanigawa, N

2015-02-01

To identify predictive factors for the development of pericardial effusion (PCE) in patients with oesophageal cancer treated with chemotherapy and radiotherapy (RT). From March 2006 to November 2012, patients with oesophageal cancer treated with chemoradiotherapy (CRT) using the following criteria were evaluated: radiation dose >50 Gy; heart included in the radiation field; dose-volume histogram (DVH) data available for analysis; no previous thoracic surgery; and no PCE before treatment. The diagnosis of PCE was independently determined by two radiologists. Clinical factors, the percentage of heart volume receiving >5-60 Gy in increments of 5 Gy (V5-60, respectively), maximum heart dose and mean heart dose were analysed. A total of 143 patients with oesophageal cancer were reviewed retrospectively. The median follow-up by CT was 15 months (range, 2.1-72.6 months) after RT. PCE developed in 55 patients (38.5%) after RT, and the median time to develop PCE was 3.5 months (range, 0.2-9.9 months). On univariate analysis, DVH parameters except for V60 were significantly associated with the development of PCE (p < 0.001). No clinical factor was significantly related to the development of PCE. Recursive partitioning analysis including all DVH parameters as variables showed a V10 cut-off value of 72.8% to be the most influential factor. The present results showed that DVH parameters are strong independent predictive factors for the development of PCE in patients with oesophageal cancer treated with CRT. A heart dosage was associated with the development of PCE with radiation and without prophylactic nodal irradiation.

SU-F-T-254: Dose Volume Histogram (DVH) Analysis of Breath Hold Vs Free Breathing Techniques for Esophageal Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Badkul, R; Doke, K; Pokhrel, D

Purpose: Lung and heart doses and associated toxicity are of concern in radiotherapy for esophageal cancer. This study evaluates the dosimetry of deep-inspiration-breath-hold (DIBH) technique as compared to freebreathing( FB) using 3D-conformal treatment(3D-CRT) of esophageal cancer. Methods: Eight patients were planned with FB and DIBH CT scans. DIBH scans were acquired using Varian RPM system. FB and DIBH CTs were contoured per RTOG-1010 to create the planning target volume(PTV) as well as organs at risk volumes(OAR). Two sets of gross target volumes(GTV) with 5cm length were contoured for each patient: proximal at the level of the carina and distal atmore » the level of gastroesophageal junction and were enlarged with appropriate margin to generate Clinical Target Volume and PTV. 3D-CRT plans were created on Eclipse planning system for 45Gy to cover 95% of PTV in 25 fractions for both proximal and distal tumors on FB and DIBH scans. For distal tumors celiac nodes were covered electively. DVH parameters for lung and heart OARs were generated and analyzed. Results: All DIBH DVH parameters were normalized to FB plan values. Average of heart-mean and heart-V40 was 0.70 and 0.66 for proximal lesions. For distal lesions ratios were 1.21 and 2.22 respectively. For DIBH total lung volume increased by 2.43 times versus FB scan. Average of lung-mean, V30, V20, V10, V5 are 0.82, 0.92, 0.76, 0.77 and 0.79 for proximal lesions and 1.17,0.66,0.87,0.93 and 1.03 for distal lesions. Heart doses were lower for breath-hold proximal lesions but higher for distal lesions as compared to free-breathing plans. Lung doses were lower for both proximal and distal breath-hold lesions except mean lung dose and V5 for distal lesions. Conclusion: This study showed improvement of OAR doses for esophageal lesions at mid-thoracic level utilizing DIBH vs FB technique but did not show consistent OAR sparing with DIBH for distal lesions.« less

Physiological Effects of Training.

DTIC Science & Technology

1985-06-25

applies only to short-term programs, the resting heart rate is norrally reduced as a result of aerobic training in all age groups. I0 Studies with ...in order to maintain cardiao output in conjunction with a decreased heart rate, stroke volume has to Increase. Stroke volume increases in the...volume is partially due too increased end diastolic volume. Thus, the pumping ability of the heart , I.e. increased stroke volume, is improved with

Multivariate Normal Tissue Complication Probability Modeling of Heart Valve Dysfunction in Hodgkin Lymphoma Survivors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cella, Laura, E-mail: laura.cella@cnr.it; Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples; Liuzzi, Raffaele

Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced asymptomatic heart valvular defects (RVD). Methods and Materials: Fifty-six patients treated with sequential chemoradiation therapy for Hodgkin lymphoma (HL) were retrospectively reviewed for RVD events. Clinical information along with whole heart, cardiac chambers, and lung dose distribution parameters was collected, and the correlations to RVD were analyzed by means of Spearman's rank correlation coefficient (Rs). For the selection of the model order and parameters for NTCP modeling, a multivariate logistic regression method using resampling techniques (bootstrapping) was applied. Model performance was evaluated using the area under themore » receiver operating characteristic curve (AUC). Results: When we analyzed the whole heart, a 3-variable NTCP model including the maximum dose, whole heart volume, and lung volume was shown to be the optimal predictive model for RVD (Rs = 0.573, P<.001, AUC = 0.83). When we analyzed the cardiac chambers individually, for the left atrium and for the left ventricle, an NTCP model based on 3 variables including the percentage volume exceeding 30 Gy (V30), cardiac chamber volume, and lung volume was selected as the most predictive model (Rs = 0.539, P<.001, AUC = 0.83; and Rs = 0.557, P<.001, AUC = 0.82, respectively). The NTCP values increase as heart maximum dose or cardiac chambers V30 increase. They also increase with larger volumes of the heart or cardiac chambers and decrease when lung volume is larger. Conclusions: We propose logistic NTCP models for RVD considering not only heart irradiation dose but also the combined effects of lung and heart volumes. Our study establishes the statistical evidence of the indirect effect of lung size on radio-induced heart toxicity.« less

Prospective evaluation of the fetal heart using Fetal Intelligent Navigation Echocardiography (FINE).

PubMed

Garcia, M; Yeo, L; Romero, R; Haggerty, D; Giardina, I; Hassan, S S; Chaiworapongsa, T; Hernandez-Andrade, E

2016-04-01

To evaluate prospectively the performance of Fetal Intelligent Navigation Echocardiography (FINE) applied to spatiotemporal image correlation (STIC) volume datasets of the normal fetal heart. In all women between 19 and 30 weeks' gestation with a normal fetal heart, an attempt was made to acquire STIC volume datasets of the apical four-chamber view if the following criteria were met: (1) fetal spine located between 5- and 7-o'clock positions; (2) minimal or absent shadowing (including a clearly visible transverse aortic arch); (3) absence of fetal breathing, hiccups, or movement; and (4) adequate image quality. Each STIC volume successfully acquired was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates of fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated. One or more STIC volumes (365 in total) were obtained successfully in 72.5% (150/207) of women undergoing ultrasound examination. Of the 365 volumes evaluated by STICLoop, 351 (96.2%) were considered to be appropriate. From the 351 STIC volumes, only one STIC volume per patient (n = 150) was analyzed using the FINE method, and consequently nine fetal echocardiography views were generated in 76-100% of cases using diagnostic planes only, in 98-100% of cases using VIS-Assistance only, and in 98-100% of cases when using a combination of diagnostic planes and/or VIS-Assistance. In women between 19 and 30 weeks' gestation with a normal fetal heart undergoing prospective sonographic examination, STIC volumes can be obtained successfully in 72.5% of cases. The FINE method can be applied to generate nine standard fetal echocardiography views in 98-100% of these cases using a combination of diagnostic planes and/or VIS-Assistance. This suggests that FINE could be implemented in fetal cardiac screening programs. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops.

PubMed

Tozzi, Piergiorgio; Maertens, Audrey; Emery, Jonathan; Joseph, Samuel; Kirsch, Matthias; Avellan, François

2017-11-24

We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk.Mock circulatory system: The device pumps a 37% glycerin solution through 2 parallel circuits, simulating the pulmonary and systemic circulations. Flow rates are acquired with a magnetic inductive flowmeter, while pressure sensors collect pressure in the left and right outflow and inflow tracts.In vitro test protocol: The pump is run at speeds ranging from 20 to 180 ejections per minute. The waveform of the pressure generated at the inflow and outflow of the 4 chambers and the flow rate in the systemic circulation are measured. At an ejection rate of 178 min-1, the RollingHeart pumps 5.3 L/min for a systemic maximal pressure gradient of 174 mmHg and a pulmonary maximal pressure gradient of 75 mmHg. The power input was 14 W, corresponding to an efficiency of 21%. The RollingHeart represents a new approach in the domain of total artificial heart. This preliminary study endorses the feasibility of a single valveless device acting as a total artificial heart.

Numerical model of total artificial heart hemodynamics and the effect of its size on stress accumulation.

PubMed

Marom, Gil; Chiu, Wei-Che; Slepian, Marvin J; Bluestein, Danny

2014-01-01

The total artificial heart (TAH) is a bi-ventricular mechanical circulatory support device that replaces the heart in patients with end-stage congestive heart failure. The device acts as blood pump via pneumatic activation of diaphragms altering the volume of the ventricular chambers. Flow in and out of the ventricles is controlled by mechanical heart valves. The aim of this study is to evaluate the flow regime in the TAH and to estimate the thrombogenic potential during systole. Toward that goal, three numerical models of TAHs of differing sizes, that include the deforming diaphragm and the blood flow from the left chamber to the aorta, are introduced. A multiphase model with injection of platelet particles is employed to calculate their trajectories. The shear stress accumulation in the three models are calculated along the platelets trajectories and their probability density functions, which represent the `thrombogenic footprint' of the device are compared. The calculated flow regime successfully captures the mitral regurgitation and the flows that open and close the aortic valve during systole. Physiological velocity magnitudes are found in all three models, with higher velocities and increased stress accumulation predicted for smaller devices.

A Physical Heart Failure Simulation System Utilizing the Total Artificial Heart and Modified Donovan Mock Circulation.

PubMed

Crosby, Jessica R; DeCook, Katrina J; Tran, Phat L; Betterton, Edward; Smith, Richard G; Larson, Douglas F; Khalpey, Zain I; Burkhoff, Daniel; Slepian, Marvin J

2017-07-01

With the growth and diversity of mechanical circulatory support (MCS) systems entering clinical use, a need exists for a robust mock circulation system capable of reliably emulating and reproducing physiologic as well as pathophysiologic states for use in MCS training and inter-device comparison. We report on the development of such a platform utilizing the SynCardia Total Artificial Heart and a modified Donovan Mock Circulation System, capable of being driven at normal and reduced output. With this platform, clinically relevant heart failure hemodynamics could be reliably reproduced as evidenced by elevated left atrial pressure (+112%), reduced aortic flow (-12.6%), blunted Starling-like behavior, and increased afterload sensitivity when compared with normal function. Similarly, pressure-volume relationships demonstrated enhanced sensitivity to afterload and decreased Starling-like behavior in the heart failure model. Lastly, the platform was configured to allow the easy addition of a left ventricular assist device (HeartMate II at 9600 RPM), which upon insertion resulted in improvement of hemodynamics. The present configuration has the potential to serve as a viable system for training and research, aimed at fostering safe and effective MCS device use. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Plasma volume status predicts prognosis in patients with acute heart failure syndromes.

PubMed

Yoshihisa, Akiomi; Abe, Satoshi; Sato, Yu; Watanabe, Shunsuke; Yokokawa, Tetsuro; Miura, Shunsuke; Misaka, Tomofumi; Sato, Takamasa; Suzuki, Satoshi; Oikawa, Masayoshi; Kobayashi, Atsushi; Yamaki, Takayoshi; Kunii, Hiroyuki; Saitoh, Shu-Ichi; Takeishi, Yasuchika

2017-01-01

The intravascular compartment is known as the plasma volume, and the extravascular compartment represents fluid within the interstitial space. Plasma volume expansion is a major symptom of heart failure. The aim of the current study was to investigate the impact of plasma volume status on the prognosis of acute heart failure syndromes. We analyzed 1115 patients with acute heart failure syndromes who were admitted to our hospital. These patients were divided into three groups based on their plasma volume status at admission: first tertile (plasma volume status <41.9%, n = 371), second tertile (41.9%⩽ plasma volume status <49.0%, n = 372), and third tertile (49.0%⩽ plasma volume status, n = 372). Plasma volume status was defined as follows: actual plasma volume = (1 - hematocrit) × [ a + ( b × body weight)] ( a=1530 in males and a=864 in females, b=41.0 in males and b=47.9 in females); ideal plasma volume = c × body weight ( c=39 in males and c=40 in females); and plasma volume status = [(actual plasma volume - ideal plasma volume)/ideal plasma volume] × 100 (%). In the Kaplan-Meier analysis, all-cause mortality, cardiac mortality and cardiac events increased progressively from the first to third tertile ( p <0.001, respectively). In the Cox proportional hazard analysis, after adjusting for potential confounding factors, plasma volume status was an independent predictor of all-cause mortality (hazard ratio 1.429, p < 0.001), cardiac mortality (hazard ratio 1.416, p = 0.001) and cardiac events (hazard ratio 1.207, p = 0.004). Increased congestion is associated with increased morbidity and mortality in heart failure patients. Plasma volume status, which represents intravascular compartment and congestion, can identify poor prognosis in patients with acute heart failure syndromes.

SU-E-T-632: A Dosimetric Comparison of the 3D-CRT Planning of Chest Wall in Post-Mastectomy Breast Cancer Patients, with and Without Breast Board Setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzaffar, Ambreen; Masood, Asif; Ullah, Haseeb

2014-06-15

Purpose: Breast boards are used in breast radiation which increases normal lung and heart doses, when supraclavicular field is included. Therefore, in this study through dose volume histogram (DVHs), lung and heart doses comparison was done between two different setups i.e. with and without breast board, for the treatment of left chest wall and supraclavicular fossa in postmastectomy left breast cancer. Methods: In this study, CT-Simulation scans of ten breast cancer patients were done with and without breast board, at Shifa International Hospitals Islamabad, to investigate the differences between the two different setups of the irradiation of left chest wallmore » in terms of lung and heart doses. For immobilization, support under the neck, shoulders and arms was used. Precise PLAN 2.15 treatment planning system (TPS) was used for 3D-CRT planning. The total prescribed dose for both the plans was 5000 cGy/25 fractions. The chest wall was treated with a pair of tangential photon fields and the upper supraclavicular nodal regions were treated with an anterior photon field. A mono-isocentric technique was used to match the tangential fields with the anterior field at the isocentre. The dose volume histogram was used to compare the doses of heart and ipsilateral lung. Results: Both the plans of each patient were generated and compared. DVH results showed that for the same PTV dose coverage, plans without breast board resulted in a reduction of lung and heart doses compared with the plans with breast board. There was significant reductions in V20, V<25 and mean doses for lung and V<9 and mean doses for heart. Conclusion: In comparison of both the plans, setup without breast board significantly reduced the dose-volume of the ipsilateral lung and heart in left chest wall patients. Waived registration request has been submitted.« less

SU-F-T-119: Development of Heart Prediction Model to Increase Accuracy of Dose Reconstruction for Radiotherapy Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosher, E; Choi, M; Lee, C

Purpose: To assess individual variation in heart volume and location in order to develop a prediction model of the heart. This heart prediction model will be used to calculate individualized heart doses for radiotherapy patients in epidemiological studies. Methods: Chest CT images for 30 adult male and 30 adult female patients were obtained from NIH Clinical Center. Image-analysis computer programs were used to segment the whole heart and 8 sub-regions and to measure the volume of each sub- region and the dimension of the whole heart. An analytical dosimetry method was used for the 30 adult female patients to estimatemore » mean heart dose during conventional left breast radiotherapy. Results: The average volumes of the whole heart were 803.37 cm{sup 3} (COV 18.8%) and 570.19 cm{sup 3} (COV 18.8%) for adult male and female patients, respectively, which are comparable with the international reference volumes of 807.69 cm{sup 3} for males and 596.15 cm{sup 3} for females. Some patient characteristics were strongly correlated (R{sup 2}>0.5) with heart volume and heart dimensions (e.g., Body Mass Index vs. heart depth in males: R{sup 2}=0.54; weight vs. heart width in the adult females: R{sup 2}=0.63). We found that the mean heart dose 3.805 Gy (assuming prescribed dose of 50 Gy) in the breast radiotherapy simulations of the 30 adult females could be an underestimate (up to 1.6-fold) or overestimate (up to 1.8-fold) of the patient-specific heart dose. Conclusion: The study showed the significant variation in patient heart volumes and dimensions, resulting in substantial dose errors when a single average heart model is used for retrospective dose reconstruction. We are completing a multivariate analysis to develop a prediction model of the heart. This model will increase accuracy in dose reconstruction for radiotherapy patients and allow us to individualize heart dose calculations for patients whose CT images are not available.« less

Decay not serious in northern red oak

Treesearch

Frederick H. Berry; John A. Beaton

1971-01-01

A study of 114 northern red oak, Quercus rubra, indicated that decay is not serious during the time necessary to produce high-quality saw logs and veneer logs. Two heart-rot fungi, Poria oleraceae and P. cocos, accounted for almost 25 percent of the total decay volume in the study trees. Basal fire wounds, dead...

Sodium metabisulphite, a preservative agent, decreases the heart capillary volume and length, and curcumin, the main component of Curcuma longa, cannot protect it.

PubMed

Noorafshan, A; Asadi-Golshan, R; Monjezi, S; Karbalay-Doust, S

2014-01-01

Sodium metabisulphite is used as an antioxidant agent in many pharmaceutical formulations. It is extensively used as a food preservative and disinfectant. It has been demonstrated that sulphite exposure can affect some organs. Curcumin, the main element of Curcuma longa, has been identified to have multiple protective properties. The present study extends the earlier works to quantitative evaluation of the effects of sulphite and curcumin on the heart structure using stereological methods. In this study, 28 rats were randomly divided into four experimental groups. The rats in groups I to IV received distilled water (group I), sodium metabisulphite (25 mg/ kg/day) (group II), curcumin (100 mg/kg/day) (group III), and sodium metabisulphite+curcumin (group IV), respectively, for 8 weeks. The left ventricle was subjected to stereological methods to estimate the quantitative parameters of the myocardium. A 20 % decrease was observed in the total volume of ventricular tissue in the sulphite-treated animals compared to the distilled water treatment (P < 0.02). Also, the volume and length of the capillaries were reduced by 43 % on average in the sulphite-treated rats in comparison to the distilled water-treated animals (P < 0.02). However, no significant change was seen in the mean and total volume of the myocardium and the cavity and diameter of the capillaries after sulphite ingestion. Treatment with curcumin did not protect the animals against the structural changes of the ventricle. Sulphite, as a preservative food agent, reduced the length and volume of the ventricular capillaries and curcumin could not protect them.

[Electroacupuncture intervention combined with general anesthesia for 80 cases of heart valve replacement surgery under cardiopulmonary bypass].

PubMed

Chi, Hao; Zhou, Wen-Xiong; Wu, Yao-Yao; Chen, Tong-Yu; Ge, Wen; Yuan, Lan; Shen, Wei-Dong; Zhou, Jia

2014-02-01

To determine whether electroacupuncture (EA) intervention combined with general anesthesia (GA) strategy can reduce early post-operative morbidity and medical costs in patients undergoing heart valve replacement operation under cardiopulmonary bypass. A total of 160 heart valve replacement surgery patients undergoing cardiopulmonary bypass were randomly divided into GA and EA + GA groups (n = 80 in each group). Patients of the GA group were given with intravenous injection of Fentanyl, Midazolam, Vecuronium Bromide, etc. and routine tracheal intubation. EA (3-4 Hz, 2.0-2.2 mA) was applied to bilateral Zhongfu (LU 1), Chize (LU 5) and Ximen (PC 4) beginning about 20 mm before the surgery in the EA + GA group. Endotracheal intubation was not employed but only prepared as a standby for patients of the EA + GA group. The dosage of narcotic drugs, duration of surgery, duration of aertic blockage, rate of cardiac re-beating, volumes of post-operative blood transfusion, discharge volume, cases of post-operative pulmonary infection, vocal cord injury, and the time of first bed-off, first eating and duration in intensive care unit (IOU) residence. etc. were recorded. The successful rates of heart valve replacement surgery were similar in both GA and EA + GA groups. Compared with the GA group, the dosages of Fentanyl, Midazolam and Vecuronium of the EA + GA group were significantly lower (P < 0.05, P < 0.01), the numbers of patients needing blood-transfusion, antibiotics treatment, and suffering from pulmonary infection were fewer, the time of first bed-off and duration of hospitalizetion and IOU residence were considerably shorter (P < 0.05, P < 0.01) and the total medical cost was obviously lower (P < 0.05) in the EA + GA group. EA combined with general anesthesia strategy for heart valve replacement surgery without endotracheal intubation is safe and can reduce post-operative morbidity and medical costs in patients undergoing heart valve replacement surgery under cardiopulmonary bypass.

Comparative stereology of the mouse and finch left ventricle.

PubMed

Bossen, E H; Sommer, J R; Waugh, R A

1978-01-01

The volume fractions and surface per unit cell volume of some subcellular components of the left ventricles of the finch and mouse were quantitated by stereologic techniques. These species were chosen for study because they have similar heart rates but differ morphologically in some respects: fiber diameter is larger in the mouse; the mouse has transverse tubules while the finch does not; and the finch has a form of junctional sarcoplasmic reticulum (JSR), extended JSR (EJSR), located in the cell interior with no direct plasmalemmal contact, while the mouse interior JSR (IJSR) abuts on transverse tubules. Our data show that the volume fraction (Vv) and surface area per unit cell volume (Sv) of total SR, and free SR (FSR) are similar. The volume fractions of mitochondria, myofibrils, and total junctional SR were also similar. The Sv of the cell surface of the finch was similar to the Sv of the cell surface of the mouse (Sv-plasmalemma plus Sv of the transverse tubules). The principal difference was in the distribution of JSR; the mouse peripheral JSR (PJSR) represents only 9% of the total JSR, while the finch PJSR accounts for 24% of the bird's JSR. The similar volume fractions of total junctional SR (PJSR + EJSR in the finch; PJSR + IJSR in the mouse) suggest that the EJSR is not an embryologic remnant, and raises the possibility that some function of JSR is independent of plasmalemmal contact.

Heart Performance Determination by Visualization in Larval Fishes: Influence of Alternative Models for Heart Shape and Volume

PubMed Central

Perrichon, Prescilla; Grosell, Martin; Burggren, Warren W.

2017-01-01

Understanding cardiac function in developing larval fishes is crucial for assessing their physiological condition and overall health. Cardiac output measurements in transparent fish larvae and other vertebrates have long been made by analyzing videos of the beating heart, and modeling this structure using a conventional simple prolate spheroid shape model. However, the larval fish heart changes shape during early development and subsequent maturation, but no consideration has been made of the effect of different heart geometries on cardiac output estimation. The present study assessed the validity of three different heart models (the “standard” prolate spheroid model as well as a cylinder and cone tip + cylinder model) applied to digital images of complete cardiac cycles in larval mahi-mahi and red drum. The inherent error of each model was determined to allow for more precise calculation of stroke volume and cardiac output. The conventional prolate spheroid and cone tip + cylinder models yielded significantly different stroke volume values at 56 hpf in red drum and from 56 to 104 hpf in mahi. End-diastolic and stroke volumes modeled by just a simple cylinder shape were 30–50% higher compared to the conventional prolate spheroid. However, when these values of stroke volume multiplied by heart rate to calculate cardiac output, no significant differences between models emerged because of considerable variability in heart rate. Essentially, the conventional prolate spheroid shape model provides the simplest measurement with lowest variability of stroke volume and cardiac output. However, assessment of heart function—especially if stroke volume is the focus of the study—should consider larval heart shape, with different models being applied on a species-by-species and developmental stage-by-stage basis for best estimation of cardiac output. PMID:28725199

Cardiovascular responses to postural changes: differences with age for women and men

NASA Technical Reports Server (NTRS)

Frey, M. A.; Tomaselli, C. M.; Hoffler, W. G.

1994-01-01

The cardiovascular responses to postural change, and how they are affected by aging, are inadequately described in women. Therefore, the authors examined the influence of age and sex on the responses of blood pressure, cardiac output, heart rate, and other variables to change in posture. Measurements were made after 10 minutes each in the supine, seated, and standing positions in 22 men and 25 women who ranged in age from 21 to 59 years. Several variables differed, both by sex and by age, when subjects were supine. On rising, subjects' diastolic and mean arterial pressures, heart rate, total peripheral resistance (TPR), and thoracic impedance increased; cardiac output, stroke volume, and mean stroke ejection rate decreased; and changes in all variables, except heart rate, were greater from supine to sitting than sitting to standing. The increase in heart rate was greater in the younger subjects, and increases in TPR and thoracic impedance were greater in the older subjects. Stroke volume decreased less, and TPR and thoracic impedance increased more, in the women than in the men. The increase in TPR was particularly pronounced in the older women. These studies show that the cardiovascular responses to standing differ, in some respects, between the sexes and with age. The authors suggest that the sex differences are, in part, related to greater decrease of thoracic blood volume with standing in women than in men, and that the age differences result, in part, from decreased responsiveness of the high-pressure baroreceptor system.

Gender-based differences in the cardiovascular response to standing

NASA Technical Reports Server (NTRS)

Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.

1991-01-01

The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.

Improvement on the auxiliary total artificial heart (ATAH) left chamber design.

PubMed

Andrade, Aron; Fonseca, Jeison; Legendre, Daniel; Nicolosi, Denys; Biscegli, Jose; Pinotti, Marcos; Ohashi, Yukio; Nosé, Yukihiko

2003-05-01

The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow. The ATAH left and right stroke volumes are 38 ml and 34 ml, respectively, giving approximately 5 L/min of cardiac output at 160 bpm. Flow visualization studies were performed in critical areas on the ATAH left chamber. A closed circuit loop was used with water and glycerin (37%) at 25 degrees C. Amberlite particles (80 mesh) were illuminated by a 1 mm planar helium-neon laser light. With left mean preload fixed at 10 mm Hg and the afterload at 100 mm Hg, the heart rate varied from 60 to 200 bpm. Two porcine valves were used on the inlet and outlet ports. The flow pattern images were obtained using a color micro-camera and a video recorder. Subsequently, these images were digitized using a PC computer. A persistent stagnant flow was detected in the left chamber inlet port. After improvement on the left chamber design, this stagnant flow disappeared.

SU-E-T-572: Normal Lung Tissue Sparing in Radiation Therapy for Locally Advanced Non-Small Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, C; Ju, S; Ahn, Y

2015-06-15

Purpose: To compare normal lung-sparing capabilities of three advanced radiation therapy techniques for locally advanced non-small cell lung cancer (LA-NSCLC). Methods: Four-dimensional computed tomography (4DCT) was performed in 10 patients with stage IIIb LA-NSCLC. The internal target volume (ITV); planning target volume (PTV); and organs at risks (OARs) such as spinal cord, total normal lung, heart, and esophagus were delineated for each CT data set. Intensity-modulated radiation therapy (IMRT), Tomohelical-IMRT (TH-IMRT), and TomoDirect-IMRT (TD-IMRT) plans were generated (total prescribed dose, 66 Gy in 33 fractions to the PTV) for each patient. To reduce the normal lung dose, complete and directionalmore » block function was applied outside the normal lung far from the target for both TH-IMRT and TD-IMRT, while pseudo- OAR was set in the same region for IMRT. Dosimetric characteristics of the three plans were compared in terms of target coverage, the sparing capability for the OAR, and the normal tissue complication probability (NTCP). Beam delivery efficiency was also compared. Results: TH-IMRT and TD-IMRT provided better target coverage than IMRT plans. Lung volume receiving ≥–30 Gy, mean dose, and NTCP were significant with TH-IMRT than with IMRT (p=0.006), and volume receiving ≥20–30 Gy was lower in TD-IMRT than in IMRT (p<0.05). Compared with IMRT, TH-IMRT had better sparing effect on the spinal cord (Dmax, NTCP) and heart (V45) (p<0.05). NTCP for the spinal cord, V45 and V60 for the heart, and Dmax for the esophagus were significantly lower in TD-IMRT than in IMRT. The monitor units per fraction were clearly smaller for IMRT than for TH-IMRT and TD-IMRT (p=0.006). Conclusion: In LA-NSCLC, TH-IMRT gave superior PTV coverage and OAR sparing compared to IMRT. TH-IMRT provided better control of the lung volume receiving ≥5–30 Gy. The delivery time and monitor units were lower in TD-IMRT than in TH-IMRT.« less

Comparing fist size to heart size is not a viable technique to assess cardiomegaly.

PubMed

Ampanozi, Garyfalia; Krinke, Eileen; Laberke, Patrick; Schweitzer, Wolf; Thali, Michael J; Ebert, Lars C

2018-05-07

Several medical textbooks state that a human heart is approximately the size of that person's fist. Stating that a heart has the size of the corpse's fist is thought to signify that the heart size is normal. We formulate two hypotheses that are tested in this article. First, we hypothesize that in cases without cardiomegaly, volumes of the hand and the heart are not significantly different. Second, we hypothesize that in cases of cardiomegaly, the heart volume statistically significantly exceeds that of the hand. We retrospectively reviewed 130 consecutive postmortem computed tomography datasets from the BLINDED starting from 01/01/2013, covering a period of approximately 3 months. Hands and hearts were segmented and their volumes estimated. We obtained the following information from the postmortem examination reports: age, sex, body length and weight, heart weight, cardiomegaly, and cause of death. When exploring the correlation between mean hand volume and heart volume, only in the group of the females with cardiomegaly (N=8) could a positive, statistically significant correlation be ascertained (Pearson correlation coefficient 0.753, P=.031). In this study, we demonstrated that the commonly used idea that a heart larger than the fist of a patient suggests cardiomegaly might be incorrect. Because this perception is commonly used in autopsy reports, it might lead to avoidable errors. Until further studies confirm this hypothesis, this informal measurement should no longer be taught or used. Copyright © 2018 Elsevier Inc. All rights reserved.

Four-chamber heart modeling and automatic segmentation for 3-D cardiac CT volumes using marginal space learning and steerable features.

PubMed

Zheng, Yefeng; Barbu, Adrian; Georgescu, Bogdan; Scheuering, Michael; Comaniciu, Dorin

2008-11-01

We propose an automatic four-chamber heart segmentation system for the quantitative functional analysis of the heart from cardiac computed tomography (CT) volumes. Two topics are discussed: heart modeling and automatic model fitting to an unseen volume. Heart modeling is a nontrivial task since the heart is a complex nonrigid organ. The model must be anatomically accurate, allow manual editing, and provide sufficient information to guide automatic detection and segmentation. Unlike previous work, we explicitly represent important landmarks (such as the valves and the ventricular septum cusps) among the control points of the model. The control points can be detected reliably to guide the automatic model fitting process. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3-D CT volumes. We formulate the segmentation as a two-step learning problem: anatomical structure localization and boundary delineation. In both steps, we exploit the recent advances in learning discriminative models. A novel algorithm, marginal space learning (MSL), is introduced to solve the 9-D similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3-D shape through learning-based boundary delineation. The proposed method has been extensively tested on the largest dataset (with 323 volumes from 137 patients) ever reported in the literature. To the best of our knowledge, our system is the fastest with a speed of 4.0 s per volume (on a dual-core 3.2-GHz processor) for the automatic segmentation of all four chambers.

Effects of Physician Volume on Readmission and Mortality in Elderly Patients with Heart Failure: Nationwide Cohort Study.

PubMed

Lee, Joo Eun; Park, Eun Cheol; Jang, Suk Yong; Lee, Sang Ah; Choy, Yoon Soo; Kim, Tae Hyun

2018-03-01

Readmission and mortality rates of patients with heart failure are good indicators of care quality. To determine whether hospital resources are associated with care quality for cardiac patients, we analyzed the effect of number of physicians and the combined effects of number of physicians and beds on 30-day readmission and 1-year mortality. We used national cohort sample data of the National Health Insurance Service (NHIS) claims in 2002-2013. Subjects comprised 2345 inpatients (age: >65 years) admitted to acute-care hospitals for heart failure. A multivariate Cox regression was used. Of the 2345 patients hospitalized with heart failure, 812 inpatients (34.6%) were readmitted within 30 days and 190 (8.1%) had died within a year. Heart-failure patients treated at hospitals with low physician volumes had higher readmission and mortality rates than high physician volumes [30-day readmission: hazard ratio (HR)=1.291, 95% confidence interval (CI)=1.020-1.633; 1-year mortality: HR=2.168, 95% CI=1.415-3.321]. Patients admitted to hospitals with low or middle bed and physician volume had higher 30-day readmission and 1-year mortality rates than those admitted to hospitals with high volume (30-day readmission: HR=2.812, 95% CI=1.561-5.066 for middle-volume beds & low-volume physicians, 1-year mortality: HR=8.638, 95% CI=2.072-36.02 for middle-volume beds & low-volume physicians). Physician volume is related to lower readmission and mortality for heart failure. Of interest, 30-day readmission and 1-year mortality were significantly associated with the combined effects of physician and institution bed volume. © Copyright: Yonsei University College of Medicine 2018

Recovery of Serum Cholesterol Predicts Survival After Left Ventricular Assist Device Implantation

PubMed Central

Vest, Amanda R.; Kennel, Peter J.; Maldonado, Dawn; Young, James B.; Mountis, Maria M.; Naka, Yoshifumi; Colombo, Paolo C.; Mancini, Donna M.; Starling, Randall C.; Schulze, P. Christian

2017-01-01

Background Advanced systolic heart failure is associated with myocardial and systemic metabolic abnormalities, including low levels of total cholesterol and low-density lipoprotein. Low cholesterol and low-density lipoprotein have been associated with greater mortality in heart failure. Implantation of a left ventricular assist device (LVAD) reverses some of the metabolic derangements of advanced heart failure. Methods and Results A cohort was retrospectively assembled from 2 high-volume implantation centers, totaling 295 continuous-flow LVAD recipients with ≥2 cholesterol values available. The cohort was predominantly bridge-to-transplantation (67%), with median age of 59 years and 49% ischemic heart failure cause. Total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride levels all significantly increased after LVAD implantation (median values from implantation to 3 months post implantation 125–150 mg/dL, 67–85 mg/dL, 32–42 mg/dL, and 97–126 mg/dL, respectively). On Cox proportional hazards modeling, patients achieving recovery of total cholesterol levels, defined as a median or greater change from pre implantation to 3 months post-LVAD implantation, had significantly better unadjusted survival (hazard ratio, 0.445; 95% confidence interval, 0.212–0.932) and adjusted survival (hazard ratio, 0.241; 95% confidence interval, 0.092–0.628) than those without cholesterol recovery after LVAD implantation. The continuous variable of total cholesterol at 3 months post implantation and the cholesterol increase from pre implantation to 3 months were also both significantly associated with survival during LVAD support. Conclusions Initiation of continuous-flow LVAD support was associated with significant recovery of all 4 lipid variables. Patients with a greater increase in total cholesterol by 3 months post implantation had superior survival during LVAD support. PMID:27623768

Systematic donor selection review process improves cardiac transplant volumes and outcomes.

PubMed

Smith, Jason W; O'Brien, Kevin D; Dardas, Todd; Pal, Jay D; Fishbein, Daniel P; Levy, Wayne C; Mahr, Claudius; Masri, Sofia C; Cheng, Richard K; Stempien-Otero, April; Mokadam, Nahush A

2016-01-01

Heart transplant remains the definitive therapy for advanced heart failure patients but is limited by organ availability. We identified a large number of donor hearts from our organ procurement organization (OPO) being exported to other regions. We engaged a multidisciplinary team including transplant surgeons, cardiologists, and our OPO colleagues to identify opportunities to improve our center-specific organ utilization rate. We performed a retrospective analysis of donor offers before and after institution of a novel review process. Each donor offer made to our program was reviewed on a monthly basis from July 2013 to June 2014 and compared with the previous year. This review process resulted in a transplant utilization rate of 28% for period 1 versus 49% for period 2 (P = .007). Limiting the analysis to offers from our local OPO changed our utilization rate from 46% to 75% (P = .02). Transplant volume increased from 22 to 35 between the 2 study periods. Thirty-day and 1-year mortality were unchanged over the 2 periods. A total of 58 hearts were refused by our center and transplanted at other centers. During period 1, the 30-day and 1-year survival rates for recipients of those organs were 98% and 90%, respectively, comparable with our historical survival data. The simple process of systematically reviewing donor turndown events as a group tended to reduce variability, increase confidence in expanded criteria for donors, and resulted in improved donor organ utilization and transplant volumes. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Effects of thyroid hormones on the heart.

PubMed

Vargas-Uricoechea, Hernando; Bonelo-Perdomo, Anilsa; Sierra-Torres, Carlos Hernán

2014-01-01

Thyroid hormones have a significant impact on heart function, mediated by genomic and non-genomic effects. Consequently, thyroid hormone deficiencies, as well as excesses, are expected to result in profound changes in cardiac function regulation and cardiovascular hemodynamics. Thyroid hormones upregulate the expression of the sarcoplasmic reticulum calcium-activated ATPase and downregulate the expression of phospholamban. Overall, hyperthyroidism is characterized by an increase in resting heart rate, blood volume, stroke volume, myocardial contractility, and ejection fraction. The development of "high-output heart failure" in hyperthyroidism may be due to "tachycardia-mediated cardiomyopathy". On the other hand, in a hypothyroid state, thyroid hormone deficiency results in lower heart rate and weakening of myocardial contraction and relaxation, with prolonged systolic and early diastolic times. Cardiac preload is decreased due to impaired diastolic function. Cardiac afterload is increased, and chronotropic and inotropic functions are reduced. Subclinical thyroid dysfunction is relatively common in patients over 65 years of age. In general, subclinical hypothyroidism increases the risk of coronary heart disease (CHD) mortality and CHD events, but not of total mortality. The risk of CHD mortality and atrial fibrillation (but not other outcomes) in subclinical hyperthyroidism is higher among patients with very low levels of thyrotropin. Finally, medications such as amiodarone may induce hypothyroidism (mediated by the Wolff-Chaikoff), as well as hyperthyroidism (mediated by the Jod-Basedow effect). In both instances, the underlying cause is the high concentration of iodine in this medication. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

Combined photon-electron beams in the treatment of the supraclavicular lymph nodes in breast cancer: A novel technique that achieves adequate coverage while reducing lung dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salem, Ahmed, E-mail: ahmed.salem@doctors.org.uk; Mohamad, Issa; Dayyat, Abdulmajeed

2015-10-01

Radiation pneumonitis is a well-documented side effect of radiation therapy for breast cancer. The purpose of this study was to compare combined photon-electron, photon-only, and electron-only plans in the radiation treatment of the supraclavicular lymph nodes. In total, 13 patients requiring chest wall and supraclavicular nodal irradiation were planned retrospectively using combined photon-electron, photon-only, and electron-only supraclavicular beams. A dose of 50 Gy over 25 fractions was prescribed. Chest wall irradiation parameters were fixed for all plans. The goal of this planning effort was to cover 95% of the supraclavicular clinical target volume (CTV) with 95% of the prescribed dosemore » and to minimize the volume receiving ≥ 105% of the dose. Comparative end points were supraclavicular CTV coverage (volume covered by the 95% isodose line), hotspot volume, maximum radiation dose, contralateral breast dose, mean total lung dose, total lung volume percentage receiving at least 20 Gy (V{sub 20} {sub Gy}), heart volume percentage receiving at least 25 Gy (V{sub 25} {sub Gy}). Electron and photon energies ranged from 8 to 18 MeV and 4 to 6 MV, respectively. The ratio of photon-to-electron fractions in combined beams ranged from 5:20 to 15:10. Supraclavicular nodal coverage was highest in photon-only (mean = 96.2 ± 3.5%) followed closely by combined photon-electron (mean = 94.2 ± 2.5%) and lowest in electron-only plans (mean = 81.7 ± 14.8%, p < 0.001). The volume of tissue receiving ≥ 105% of the prescription dose was higher in the electron-only (mean = 69.7 ± 56.1 cm{sup 3}) as opposed to combined photon-electron (mean = 50.8 ± 40.9 cm{sup 3}) and photon-only beams (mean = 32.2 ± 28.1 cm{sup 3}, p = 0.114). Heart V{sub 25} {sub Gy} was not statistically different among the plans (p = 0.999). Total lung V{sub 20} {sub Gy} was lowest in electron-only (mean = 10.9 ± 2.3%) followed by combined photon-electron (mean = 13.8 ± 2.3%) and highest in photon-only plans (mean = 16.2 ± 3%, p < 0.001). As expected, photon-only plans demonstrated the highest target coverage and total lung V{sub 20} {sub Gy}. The superiority of electron-only beams, in terms of decreasing lung dose, is set back by the dosimetric hotspots associated with such plans. Combined photon-electron treatment is a feasible technique for supraclavicular nodal irradiation and results in adequate target coverage, acceptable dosimetric hotspot volume, and slightly reduced lung dose.« less

Small-volume amnioinfusion: a potential stimulus of intrapartum fetal heart rate accelerations.

PubMed

Wax, Joseph R; Flaherty, Nina; Pinette, Michael G; Blackstone, Jacquelyn; Cartin, Angelina

2004-02-01

We describe a recurrent nonreassuring fetal heart rate pattern in which small-volume amnioinfusions apparently evoked fetal heart rate accelerations suggested fetal well-being, allowing that progressive labor that culminated in the vaginal delivery of a healthy infant.

The effect of empagliflozin on muscle sympathetic nerve activity in patients with type II diabetes mellitus.

PubMed

Jordan, Jens; Tank, Jens; Heusser, Karsten; Heise, Tim; Wanner, Christoph; Heer, Martina; Macha, Sreeraj; Mattheus, Michaela; Lund, Søren S; Woerle, Hans J; Broedl, Uli C

2017-09-01

Inhibition of sodium glucose cotransporter 2 with empagliflozin results in caloric loss by increasing urinary glucose excretion and has a mild diuretic effect. Diuretic effects are usually associated with reflex-mediated increases in sympathetic tone, whereas caloric loss is associated with decreased sympathetic tone. In an open-label trial, muscle sympathetic nerve activity (MSNA) (burst frequency, burst incidence, and total MSNA) was assessed using microneurography performed off-treatment and on day 4 of treatment with empagliflozin 25 mg once daily in 22 metformin-treated patients with type II diabetes (mean [range] age 54 [40-65] years). Systolic and diastolic blood pressure (BP), heart rate, urine volume, and body weight were assessed before and on day 4 (BP, heart rate), day 5 (urine volume), or day 6 (body weight) of treatment with empagliflozin. After 4 days of treatment with empagliflozin, no significant changes in MSNA were apparent despite a numerical increase in urine volume, numerical reductions in BP, and significant weight loss. There were no clinically relevant changes in heart rate. Empagliflozin is not associated with clinically relevant reflex-mediated sympathetic activation in contrast to increases observed with diuretics in other studies. Our study suggests a novel mechanism through which sodium glucose cotransporter 2 inhibition affects human autonomic cardiovascular regulation. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

A comparison of romifidine and xylazine when used with diazepam/ketamine for short duration anesthesia in the horse.

PubMed Central

Kerr, C L; McDonell, W N; Young, S S

1996-01-01

The purpose of this study was to compare and evaluate sedation with intravenous xylazine (1.1 mg/kg bodyweight [BW]) versus intravenous romifidine (100 micrograms/kg BW) followed by induction of anesthesia with intravenous diazepam (0.04 mg/kg BW) and ketamine (2.2 mg/kg BW). Twelve healthy horses were used in a blinded, randomized, cross-over design. Heart rate, presence of 2nd degree atrioventricular heart blocks (2 degrees AVB), respiratory rate, arterial blood pressures, blood gases, packed cell volume, total serum proteins, and duration of anesthesia and recumbency were recorded. Induction and recovery quality was evaluated using a 0 to 4 score. Response to stimulation with noise, pressure, and cutaneous electrical stimulation was assessed at 5 minute intervals during recumbency to evaluate the depth of anesthesia. Heart rate was lower and 2 degrees AVB more frequent in the romifidine group, while blood pressure was lower in the xylazine group. Duration of anesthesia was longer in the romifidine group (mean 20.8, s mean 2.3 min) versus the xylazine group (mean 15.8, s mean 1.6 min), while induction and recovery were excellent in both groups. Respiratory rates, blood gas values, packed cell volumes, and total protein levels did not differ between groups. The results indicate that romifidine premedication followed by diazepam and ketamine is a very satisfactory regime for short duration intravenous anesthesia in horses. PMID:8896874

WE-DE-209-01: Dosimetric Benefits of DIBH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howell, R.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

WE-DE-209-02: Active Breathing Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comsa, D.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

WE-DE-209-03: Spirometric Motion Management System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, S.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

Blood circulation in the ascidian tunicate Corella inflata (Corellidae)

PubMed Central

2016-01-01

The body of the ascidian tunicate Corella inflata is relatively transparent. Thus, the circulatory system can be visualized by injecting high molecular weight fluorescein labeled dextran into the heart or the large vessels at the ends of the heart without surgery to remove the body wall. In addition, after staining with neutral red, the movement of blood cells can be easily followed to further characterize the circulatory system. The heart is two gently curved concentric tubes extending across the width of the animal. The inner myocardial tube has a partial constriction approximately in the middle. As in other tunicates, the heart is peristaltic and periodically reverses direction. During the branchial phase blood leaves the anterior end of the heart by two asymmetric vessels that connect to the two sides of the branchial basket. Blood then flows in both transverse directions through a complex system of ducts in the basket into large ventral and dorsal vessels which carry blood back to the visceral organs in the posterior of the animal. During the visceral phase blood leaves the posterior end of the heart in two vessels that repeatedly bifurcate and fan into the stomach and gonads. Blood velocity, determined by following individual cells in video frames, is high and pulsatory near the heart. A double peak in velocity at the maximum may be due to the constriction in the middle of the heart tube. Blood velocity progressively decreases with distance from the heart. In peripheral regions with vessels of small diameter blood cells frequently collide with vessel walls and cell motion is erratic. The estimated volume of blood flow during each directional phase is greater than the total volume of the animal. Circulating blood cells are confined to vessels or ducts in the visible parts of the animal and retention of high molecular weight dextran in the vessels is comparable to that seen in vertebrates. These are characteristics of a closed circulatory system. PMID:27994977

Relationship between central and peripheral atherosclerosis and left ventricular dysfunction in a community population.

PubMed

Tsao, Connie W; Gona, Philimon; Salton, Carol; Murabito, Joanne M; Oyama, Noriko; Danias, Peter G; O'Donnell, Christopher J; Manning, Warren J; Yeon, Susan B

2011-08-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and peripheral artery disease (PAD) in a community cohort. A total of 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65 ± 9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional left ventricular systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at the most contemporaneous examination visit. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p < 0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p < 0.001) and volume of aortic plaque were associated with decreased ABI (p < 0.001). After multivariable adjustment, an ABI ≤ 0.9 or prior revascularization was associated with a threefold odds of aortic plaque (p = 0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p < 0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment, suggesting shared mechanisms beyond those captured by traditional risk factors.

Sleep-disordered breathing, brain volume, and cognition in older individuals with heart failure.

PubMed

Moon, Chooza; Melah, Kelsey E; Johnson, Sterling C; Bratzke, Lisa C

2018-06-19

Sleep-disordered breathing is common in individuals with heart failure and may contribute to changes in the brain and decreased cognition. However, limited research has explored how the apnea-hypopnea index contributes to brain structure and cognition in this population. The aims of this study were to explore how the apnea-hypopnea index is associated with brain volume and cognition in heart failure patients. Data of 28 heart failure patients (mean age = 67.93; SD = 5.78) were analyzed for this cross-sectional observational study. We evaluated the apnea-hypopnea index using a portable multichannel sleep-monitoring device. All participants were scanned using 3.0 Tesla magnetic resonance imaging and neuropsychological tests. Brain volume was evaluated using a voxel-based morphometry method with T1-weighted images. We used multiple regressions to analyze how the apnea-hypopnea index is associated with brain volume and cognition. We found an inverse association between apnea-hypopnea index scores and white matter volume (β = -0.002, p = 0.026), but not in gray matter volume (β = -0.001, p = 0.237). Higher apnea-hypopnea index was associated with reduced regional gray and white matter volume (p < 0.001, uncorrected). Cognitive scores were not associated with the apnea-hypopnea index (p-values were >0.05). Findings from this study provide exploratory evidence that higher apnea-hypopnea index may be associated with greater brain volume reduction in heart failure patients. Future studies are needed to establish the relationship between sleep-disordered breathing, brain volume, and cognition in heart failure samples. © 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

Blood Volume: Its Adaptation to Endurance Training

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1991-01-01

Expansion of blood volume (hypervolemia) has been well documented in both cross-sectional and longitudinal studies as a consequence of endurance exercise training. Plasma volume expansion can account for nearly all of the exercise-induced hypervolemia up to 2-4 wk; after this time expansion may be distributed equally between plasma and red cell volumes. The exercise stimulus for hypervolemia has both thermal and nonthermal components that increase total circulating plasma levels of electrolytes and proteins. Although protein and fluid shifts from the extravascular to intravascular space may provide a mechanism for rapid hypervolemia immediately after exercise, evidence supports the notion that chronic hypervolemia associated with exercise training represents a net expansion of total body water and solutes. This net increase of body fluids with exercise training is associated with increased water intake and decreased urine volume output. The mechanism of reduced urine output appears to be increased renal tubular reabsorption of sodium through a more sensitive aldosterone action in man. Exercise training-induced hypervolemia appears to be universal among most animal species, although the mechanisms may be quite different. The hypervolemia may provide advantages of greater body fluid for heat dissipation and thermoregulatory stability as well as larger vascular volume and filling pressure for greater cardiac stroke volume and lower heart rates during exercise.

Importance of the splanchnic vascular bed in human blood pressure regulation.

NASA Technical Reports Server (NTRS)

Rowell, L. B.; Detry, J.-M. R.; Blackmon, J. R.; Wyss, C.

1972-01-01

Three-part experiment in which five subjects were exposed to lower body negative pressure (LBNP) at -50 mm Hg below the iliac crests. Duration of LBNP to earliest vagal symptoms was 7 to 21 min; all data are expressed as changes from control period to the last measurements before these symptoms. In part I, forearm blood flow (by Whitney gauge) fell 45% during LBNP. In part II, splanchnic blood flow (from arterial clearance hepatic extraction of indocyanine green) fell 32% and splanchnic vascular resistance rose 30%. In part III, cardiac output fell 28%, stroke volume 51%, and central blood volume 21%. Total peripheral resistance and heart rate rose 19% and 52%. Of the reduction in total vascular conductance, decreased splanchnic conductance accounted for approximately 33%; skin plus muscle conductance decreased similarly.

Simulated stand tests and centrifuge training to prevent orthostatic intolerance on Earth, moon, and Mars.

PubMed

Coats, Brandon W; Sharp, M Keith

2010-03-01

One proposed method to overcome postflight orthostatic intolerance is for astronauts to undergo inflight centrifugation. Cardiovascular responses were compared between centrifuge and gravitational conditions using a seven-compartment cardiovascular model. Vascular resistance, heart rate, and stroke volume values were adopted from literature, while compartmental volumes and compliances were derived from impedance plethysmography of subjects (n=8) riding on a centrifuge. Three different models were developed to represent the typical male subject who completed a 10-min postflight stand test ("male finisher"), "non-finishing male" and "female" (all non-finishers). A sensitivity analysis found that both cardiac output and arterial pressure were most sensitive to total blood volume. Simulated stand tests showed that female astronauts were more susceptible to orthostatic intolerance due to lower initial blood pressure and higher pressure threshold for presyncope. Rates of blood volume loss by capillary filtration were found to be equivalent in female and male non-finishers, but four times smaller in male finishers. For equivalent times to presyncope during centrifugation as those during constant gravity, lower G forces at the level of the heart were required. Centrifuge G levels to match other cardiovascular parameters varied depending on the parameter, centrifuge arm length, and the gravity level being matched.

SU-F-J-22: Lung VolumeVariability Assessed by Bh-CBCT in 3D Surface Image Guided Deep InspirationBreath Hold (DIBH) Radiotherapy for Left-Sided Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutierrez, A; Stanley, D; Papanikolaou, N

Purpose: With the increasing use of DIBH techniques for left-sided breast cancer, 3D surface-image guided DIBH techniques have improved patient setup and facilitated DIBH radiation delivery. However, quantification of the daily separation between the heart and left breast still presents a challenge. One method of assuring separation is to ensure consistent left lung filling. With this in mind, the aim of this study is to retrospectively quantify left lung volume from weekly breath hold-CBCTs (bh-CBCT) of left-sided breast patients treated using a 3D surface imaging system. Methods: Ten patients (n=10) previously treated to the left breast using the C-Rad CatalystHDmore » system (C-RAD AG, Uppsala Sweden) were evaluated. Patients were positioned with CatalystHD and with bh-CBCT. bh-CBCTs were acquired at the validation date, first day of treatment and at subsequent weekly intervals. Total treatment courses spanned from 3 to 5 weeks. bh-CBCT images were exported to VelocityAI and the left lung volume was segmented. Volumes were recorded and analyzed. Results: A total of 41 bh-CBCTs were contoured in VelocityAI for the 10 patients. The mean left lung volume for all patients was 1657±295cc based on validation bh-CBCT. With the subsequent lung volumes normalized to the validation lung volume, the mean relative ratios for all patients were 1.02±0.11, 0.97±0.14, 0.98±0.11, 1.02±0.01, and 0.96±0.02 for week 1, 2, 3, 4, and 5, respectively. Overall, the mean left lung volume change was ≤4.0% over a 5-week course; however left lung volume variations of up to 28% were noted in a select patient. Conclusion: With the use of the C-RAD CatalystHD system, the mean lung volume variability over a 5-week course of DIBH treatments was ≤4.0%. By minimizing left lung volume variability, heart to left breast separation maybe more consistently maintained. AN Gutierrez has a research grant from C-RAD AG.« less

Hospital Volume and 30-Day Mortality for Three Common Medical Conditions

PubMed Central

Ross, Joseph S.; Normand, Sharon-Lise T.; Wang, Yun; Ko, Dennis T.; Chen, Jersey; Drye, Elizabeth E.; Keenan, Patricia S.; Lichtman, Judith H.; Bueno, Héctor; Schreiner, Geoffrey C.; Krumholz, Harlan M.

2010-01-01

Background The association between hospital volume and the death rate for patients who are hospitalized for acute myocardial infarction, heart failure, or pneumonia remains unclear. It is also not known whether a volume threshold for such an association exists. Methods We conducted cross-sectional analyses of data from Medicare administrative claims for all fee-for-service beneficiaries who were hospitalized between 2004 and 2006 in acute care hospitals in the United States for acute myocardial infarction, heart failure, or pneumonia. Using hierarchical logistic-regression models for each condition, we estimated the change in the odds of death within 30 days associated with an increase of 100 patients in the annual hospital volume. Analyses were adjusted for patients’ risk factors and hospital characteristics. Bootstrapping procedures were used to estimate 95% confidence intervals to identify the condition-specific volume thresholds above which an increased volume was not associated with reduced mortality. Results There were 734,972 hospitalizations for acute myocardial infarction in 4128 hospitals, 1,324,287 for heart failure in 4679 hospitals, and 1,418,252 for pneumonia in 4673 hospitals. An increased hospital volume was associated with reduced 30-day mortality for all conditions (P<0.001 for all comparisons). For each condition, the association between volume and outcome was attenuated as the hospital's volume increased. For acute myocardial infarction, once the annual volume reached 610 patients (95% confidence interval [CI], 539 to 679), an increase in the hospital volume by 100 patients was no longer significantly associated with reduced odds of death. The volume threshold was 500 patients (95% CI, 433 to 566) for heart failure and 210 patients (95% CI, 142 to 284) for pneumonia. Conclusions Admission to higher-volume hospitals was associated with a reduction in mortality for acute myocardial infarction, heart failure, and pneumonia, although there was a volume threshold above which an increased condition-specific hospital volume was no longer significantly associated with reduced mortality. PMID:20335587

Inadequate increase in the volume of major epicardial coronary arteries compared with that in left ventricular mass. Novel concept for characterization of coronary arteries using 64-slice computed tomography.

PubMed

Ehara, Shoichi; Okuyama, Takuhiro; Shirai, Nobuyuki; Sugioka, Kenichi; Oe, Hiroki; Itoh, Toshihide; Matsuoka, Toshiyuki; Ikura, Yoshihiro; Ueda, Makiko; Naruko, Takahiko; Hozumi, Takeshi; Yoshiyama, Minoru

2009-08-01

Previous studies have shown a correlation between coronary artery cross-sectional diameter and left ventricular (LV) mass. However, no studies have examined the correlation between actual coronary artery volume (CAV) and LV mass. In the present study, measurements of CAV by 64-multislice computed tomography (MSCT) were validated and the relationship between CAV and LV mass was investigated. First, coronary artery phantoms consisting of syringes filled with solutions of contrast medium moving at simulated heart rates were scanned by 64-MSCT. Display window settings permitting accurate calculation of small volumes were optimized by evaluating volume-rendered images of the segmented contrast medium at different window settings. Next, 61 patients without significant coronary artery stenosis were scanned by 64-MSCT with the same protocol as for the phantoms. Coronary arteries were segmented on a workstation and the same window settings were applied to the volume-rendered images to calculate total CAV. Significant correlations between total CAV and LV mass (r=0.660, P<0.0001) were found, whereas an inverse relation was present between total CAV per 100 g of LV mass and LV mass. The novel concept of "CAV" for the characterization of coronary arteries may prove useful for future research, particularly on the causes of LV hypertrophy.

[Development and evaluation of individualized fluid therapy in the elderly patients with coronary heart disease undergoing gastrointestinal surgery: a randomized, controlled trial].

PubMed

Zheng, Hong; Guo, Hai; Ye, Jian-rong; Chen, Lin

2012-06-01

To develop and evaluate an individualized fluid therapy in the elderly patients with coronary heart disease undergoing gastrointestinal surgery. In this prospective study, 60 coronary heart disease patients undergoing gastrointestinal surgery were included in the First Affiliated Hospital of Xinjiang Medical University from March 2009 to March 2012. Patients were randomized into the intervention group and the control group with 30 patients in each group. Individualized fluid therapy was used during surgery and postoperative period in the ICU, which was determined based on target controlled fluid therapy according to cardiac index, stroke volume, and stroke volume variation. Traditional fluid therapy was used in the control group in the intraoperative and postoperative period. The two groups were compared in terms of postoperative hemodynamic parameters, total fluid volume, incidence of adverse cardiac events, and recovery of bowel function. Compared with the control group, mean arterial pressure was significantly increased at the commencement of the surgery. The cardiac index was significantly elevated during surgery and at the end of the surgery. Stroke volume was significantly increased after induction of anesthesia, during the surgery, and at the early stay of ICU period(all P<0.05). Serum lactic acid in the intervention group was significantly lower at the end of surgery and during ICU stay than that in the control group (all P<0.05). During surgery and 24-hour stay in ICU, the total fluid volume, crystal usage, and urine were significantly less, while colloidal fluid use was significantly more in the intervention group as compared to the control group(all P<0.05). The perioperative adverse cardiac event rate was 36.7%(11/30) in the intervention group, lower than 56.7%(17/30) in the control group, but the difference was no statistically significance(P>0.05). In the intervention group, defecation time, time to first flatus, resumption of liquid intake, length of ICU stay and hospital stay were significantly less compared with the control group(P<0.05). In the elderly patients with coronary arterial disease undergoing gastrointestinal surgery, individualized fluid therapy can effectively decrease adverse cardiac events, improve postoperative gastrointestinal function, and reduce length of hospital stay.

Morphological phenotyping of mouse hearts using optical coherence tomography

NASA Astrophysics Data System (ADS)

Cua, Michelle; Lin, Eric; Lee, Ling; Sheng, Xiaoye; Wong, Kevin S. K.; Tibbits, Glen F.; Beg, Mirza Faisal; Sarunic, Marinko V.

2014-11-01

Transgenic mouse models have been instrumental in the elucidation of the molecular mechanisms behind many genetically based cardiovascular diseases such as Marfan syndrome (MFS). However, the characterization of their cardiac morphology has been hampered by the small size of the mouse heart. In this report, we adapted optical coherence tomography (OCT) for imaging fixed adult mouse hearts, and applied tools from computational anatomy to perform morphometric analyses. The hearts were first optically cleared and imaged from multiple perspectives. The acquired volumes were then corrected for refractive distortions, and registered and stitched together to form a single, high-resolution OCT volume of the whole heart. From this volume, various structures such as the valves and myofibril bundles were visualized. The volumetric nature of our dataset also allowed parameters such as wall thickness, ventricular wall masses, and luminal volumes to be extracted. Finally, we applied the entire acquisition and processing pipeline in a preliminary study comparing the cardiac morphology of wild-type mice and a transgenic mouse model of MFS.

WE-DE-209-05: Self-Held Breath Control with Respiratory Monitoring and Feedback Guidance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gifford, K.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

WE-DE-209-04: 3D Surface Image-Guided

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, X.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

WE-DE-209-00: Practical Implementation of Deep Inspiration Breath Hold Techniques for Breast Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

Estimating cardiac fiber orientations in pig hearts using registered ultrasound and MR image volumes

NASA Astrophysics Data System (ADS)

Dormer, James D.; Meng, Yuguang; Zhang, Xiaodong; Jiang, Rong; Wagner, Mary B.; Fei, Baowei

2017-03-01

Heart fiber mechanics can be important predictors in current and future cardiac function. Accurate knowledge of these mechanics could enable cardiologists to provide a diagnosis before conditions progress. Magnetic resonance diffusion tensor imaging (MR-DTI) has been used to determine cardiac fiber orientations. Ultrasound is capable of providing anatomical information in real time, enabling a physician to quickly adjust parameters to optimize image scans. If known fiber orientations from a template heart measured using DTI can be accurately deformed onto a cardiac ultrasound volume, fiber orientations could be estimated for the patient without the need for a costly MR scan while still providing cardiologists valuable information about the heart mechanics. In this study, we apply the method to pig hearts, which are a close representation of human heart anatomy. Experiments from pig hearts show that the registration method achieved an average Dice similarity coefficient (DSC) of 0.819 +/- 0.050 between the ultrasound and deformed MR volumes and that the proposed ultrasound-based method is able to estimate the cardiac fiber orientation in pig hearts.

Coronary artery calcification identification and labeling in low-dose chest CT images

NASA Astrophysics Data System (ADS)

Xie, Yiting; Liu, Shuang; Miller, Albert; Miller, Jeffrey A.; Markowitz, Steven; Akhund, Ali; Reeves, Anthony P.

2017-03-01

A fully automated computer algorithm has been developed to evaluate coronary artery calcification (CAC) from lowdose CT scans. CAC is identified and evaluated in three main coronary artery groups: Left Main and Left Anterior Descending Artery (LM + LAD) CAC, Left Circumflex Artery (LCX) CAC, and Right Coronary Artery (RCA) CAC. The artery labeling is achieved by segmenting all CAC candidates in the heart region and applying geometric constraints on the candidates using locally pre-identified anatomy regions. This algorithm was evaluated on 1,359 low-dose ungated CT scans, in which each artery CAC content was categorically visually scored by a radiologist into none, mild, moderate and extensive. The Spearman correlation coefficient R was used to assess the agreement between three automated CAC scores (Agatston-weighted, volume, and mass) and categorical visual scores. For Agatston-weighted automated scores, R was 0.87 for total CAC, 0.82 for LM + LAD CAC, 0.66 for LCX CAC and 0.72 for RCA CAC; results using volume and mass scores were similar. CAC detection sensitivities were: 0.87 for total, 0.82 for LM + LAD, 0.65 for LCX and 0.74 for RCA. To assess the impact of image noise, the dataset was further partitioned into three subsets based on heart region noise level (low<=80HU, medium=(80HU, 110HU], high>110HU). The low and medium noise subsets had higher sensitivities and correlations than the high noise subset. These results indicate that location specific heart risk assessment is possible from low-dose chest CT images.

True Anemia-Red Blood Cell Volume Deficit-in Heart Failure: A Systematic Review.

PubMed

Montero, David; Lundby, Carsten; Ruschitzka, Frank; Flammer, Andreas J

2017-05-01

Anemia in heart failure (HF) is commonly diagnosed according to hemoglobin concentration [Hb], hence may be the result of hemodilution or true red blood cell volume (RBCV) deficit. Whether true (nonhemodilutional) anemia in HF can or cannot be generally inferred by [Hb] measurements and clinical correlates remains unclear. The purpose of this study was to systematically review the literature and investigate the status and correlates of RBCV in patients with HF. MEDLINE, Scopus, and Web of Science were searched since their inceptions until April 2016 for articles directly reporting or allowing the calculation of intravascular volumes (RBCV, plasma volume) in patients with HF according to the International Council for Standardization in Hematology. Eighteen studies were included after systematic review, comprising a total of 368 patients with HF (limits for mean age=49-80 years, sex=0%-92% females, left ventricular ejection fraction=26%-61%). Mean RBCV was reduced (limits=67%-88% of normal) in all studies including HF patients with anemia (low [Hb]) (7 studies, n=127), whereas only 2 of 10 studies in nonanemic patients with HF presented lower than normal mean RBCV (90% and 96%). In metaregression analyses, RBCV was positively associated with [Hb] ( B =6.10, SE=1.44) and negatively associated with age ( B =-1.14, SE=0.23), % females ( B =-0.38, SE=0.04), left ventricular ejection fraction ( B =-0.81, SE=0.20), and body mass index ( B =-3.55, SE=0.46; P <0.001). Presence or absence of true anemia in patients with HF as determined by RBCV status mainly concurs with diagnosis based on [Hb] and presents negative relationships with age, female sex, left ventricular ejection fraction, and body mass index. © 2017 American Heart Association, Inc.

Pressure overload differentially affects respiratory capacity in interfibrillar and subsarcolemmal mitochondria.

PubMed

Schwarzer, Michael; Schrepper, Andrea; Amorim, Paulo A; Osterholt, Moritz; Doenst, Torsten

2013-02-15

Years ago a debate arose as to whether two functionally different mitochondrial subpopulations, subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM), exist in heart muscle. Nowadays potential differences are often ignored. Presumably, SSM are providing ATP for basic cell function, whereas IFM provide energy for the contractile apparatus. We speculated that two distinguishable subpopulations exist that are differentially affected by pressure overload. Male Sprague-Dawley rats were subjected to transverse aortic constriction for 20 wk or sham operation. Contractile function was assessed by echocardiography. Heart tissue was analyzed by electron microscopy. Mitochondria were isolated by differential centrifugation, and respiratory capacity was analyzed using a Clark electrode. Pressure overload induced left ventricular hypertrophy with increased posterior wall diameter and impaired contractile function. Mitochondrial state 3 respiration in control was 50% higher in IFM than in SSM. Pressure overload significantly impaired respiratory rates in both IFM and SSM, but in SSM to a lower extent. As a result, there were no differences between SSM and IFM after 20 wk of pressure overload. Pressure overload reduced total citrate synthase activity, suggesting reduced total mitochondrial content. Electron microscopy revealed normal morphology of mitochondria but reduced total mitochondrial volume density. In conclusion, IFM show greater respiratory capacity in the healthy rat heart and a greater depression of respiratory capacity by pressure overload than SSM. The differences in respiratory capacity of cardiac IFM and SSM in healthy hearts are eliminated with pressure overload-induced heart failure. The strong effect of pressure overload on IFM together with the simultaneous appearance of mitochondrial and contractile dysfunction may support the notion of IFM primarily producing ATP for contractile function.

Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis.

PubMed

Jantarasaengaram, Surasak; Vairojanavong, Kittipong

2010-09-15

Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes.

Three-Dimensional Right Ventricular Strain Versus Volume Quantification in Heart Transplant Recipients in Relation to Pulmonary Artery Pressure.

PubMed

Sade, Leyla Elif; Kozan, Hatice; Eroglu, Serpil; Pirat, Bahar; Aydinalp, Alp; Sezgin, Atilla; Muderrisoglu, Haldun

2017-02-01

Residual pulmonary hypertension challenges the right ventricular function and worsens the prognosis in heart transplant recipients. The complex geometry of the right ventricle complicates estimation of its function with conventional transthoracic echocardiography. We evaluated right ventricular function in heart transplant recipients with the use of 3-dimensional echocardiography in relation to systolic pulmonary artery pressure. We performed 32 studies in 26 heart transplant patients, with 6 patients having 2 studies at different time points with different pressures and thus included. Right atrial volume, tricuspid annular plane systolic excursion, peak systolic annular velocity, fractional area change, and 2-dimensional speckle tracking longitudinal strain were obtained by 2-dimensional and tissue Doppler imaging. Three-dimensional right ventricular volumes, ejection fraction, and 3-dimensional right ventricular strain were obtained from the 3-dimensional data set by echocardiographers. Systolic pulmonary artery pressure was obtained during right heart catheterization. Overall mean systolic pulmonary artery pressure was 26 ± 7 mm Hg (range, 14-44 mmHg). Three-dimensional end-diastolic (r = 0.75; P < .001) and end-systolic volumes (r = 0.55; P = .001)correlated well with systolic pulmonary artery pressure. Right ventricular ejection fraction and right atrium volume also significantly correlated with systolic pulmonary artery pressure (r = 0.49 and P = .01 for both). However, right ventricular 2- and 3-dimensional strain, tricuspid annular plane systolic excursion, and tricuspid annular velocity did not. The effects of pulmonary hemodynamic burden on right ventricular function are better estimated by a 3-dimensional volume evaluation than with 3-dimensional longitudinal strain and other 2-dimensional and tissue Doppler measurements. These results suggest that the peculiar anatomy of the right ventricle necessitates 3-dimensional volume quantification in heart transplant recipients in relation to residual pulmonary hypertension.

Are You Bleeding? Validation of a Machine-learning Algorithm for Determination of Blood Volume Status: Application to Remote Triage

DTIC Science & Technology

2014-01-09

workloads were determined by matching heart rate responses from each LBNP level. Heart rate and stroke volume (SV) were measured via Finom- eter. ECG, heat...learning algorithm for the assessment of central blood volume via pulse pressure [a noninvasive surrogate of stroke volume (SV)]. These data...30 130 125 120 115 110 105 100 Actual - Finometer Predicted - Algorithm Fig. 3. Comparison of average stroke volume (SV) derived from the

Frequency, Type, and Volume of Leisure-Time Physical Activity and Risk of Coronary Heart Disease in Young Women.

PubMed

Chomistek, Andrea K; Henschel, Beate; Eliassen, A Heather; Mukamal, Kenneth J; Rimm, Eric B

2016-07-26

The inverse association between physical activity and coronary heart disease (CHD) risk has primarily been shown in studies of middle-aged and older adults. Evidence for the benefits of frequency, type, and volume of leisure-time physical activity in young women is limited. We conducted a prospective analysis among 97 230 women aged 27 to 44 years at baseline in 1991. Leisure-time physical activity was assessed biennially by questionnaire. Cox proportional hazards models were used to examine the associations between physical activity frequency, type, and volume, and CHD risk. During 20 years of follow-up, we documented 544 incident CHD cases. In multivariable-adjusted models, the hazard ratio (95% confidence interval) of CHD comparing ≥30 with <1 metabolic equivalent of task-hours/wk of physical activity was 0.75 (0.57-0.99) (P, trend=0.01). Brisk walking alone was also associated with significantly lower CHD risk. Physical activity frequency was not associated with CHD risk when models also included overall activity volume. Finally, the association was not modified by body mass index (kg/m(2)) (P, interaction=0.70). Active women (≥30 metabolic equivalent of task-hours/wk) with body mass index<25 kg/m(2) had 0.52 (95% confidence interval, 0.35-0.78) times the rate of CHD in comparison with women who were obese (body mass index≥30 kg/m(2)) and inactive (physical activity <1 metabolic equivalent of task-hours/wk). These prospective data suggest that total volume of leisure-time physical activity is associated with lower risk of incident CHD among young women. In addition, this association was not modified by weight, emphasizing that it is important for normal weight, overweight, and obese women to be physically active. © 2016 American Heart Association, Inc.

Dexmedetomidine Pharmacology in Neonates and Infants After Open Heart Surgery.

PubMed

Su, Felice; Gastonguay, Marc R; Nicolson, Susan C; DiLiberto, MaryAnn; Ocampo-Pelland, Alanna; Zuppa, Athena F

2016-05-01

Dexmedetomidine is a highly selective α2-agonist with hypnotic, analgesic, and anxiolytic properties. Despite off-label administration, dexmedetomidine has found a niche in critically ill neonates and infants with congenital heart disease because of its minimal effects on respiratory function at sedative doses, facilitating early extubation and fast-track postoperative care. There are little pharmacokinetic data regarding newborns who have immature drug metabolizing capacity and who are at risk for reduced dexmedetomidine clearance and drug toxicity. The aim of this study was to determine the pharmacokinetics of dexmedetomidine in neonates and infants after open heart surgery. This study included 23 evaluable neonates (age, 1 day-1 month) and 36 evaluable infants (age, 1 month-24 months) after open heart surgery. Full-term neonates and infants requiring mechanical ventilation after open heart surgery received dexmedetomidine in a dose-escalation study. Dexmedetomidine was administered as a loading dose over 10 minutes followed by a continuous IV infusion up to 24 hours. Cohorts of 12 infants were enrolled sequentially to receive 0.35, 0.7, or 1 μg/kg dexmedetomidine followed by 0.25, 0.5, or 0.75 μg/kg/h dexmedetomidine, respectively. Cohorts of 9 neonates received 0.25, 0.35, or 0.5 μg/kg dexmedetomidine followed by 0.2, 0.3, or 0.4 μg/kg/h dexmedetomidine, respectively. Plasma dexmedetomidine concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population nonlinear mixed effects modeling approach was used to characterize dexmedetomidine pharmacokinetics. Pharmacokinetic parameters of dexmedetomidine were estimated using a 2-compartment disposition model with weight allometrically scaled as a covariate on drug clearance, intercompartmental clearance, central and peripheral volume of distributions and age, total bypass time, and intracardiac shunting on clearance. Dexmedetomidine demonstrated a plasma drug clearance of 657 × (weight/70) mL/min, intercompartmental clearance of 6780 × (weight/70) mL/min, central volume of distribution of 88 × (weight/70) L and peripheral volume of distribution of 112 × (weight/70) L for a typical subject with age >1 month with a cardiopulmonary bypass time of 60 minutes and without right-to-left intracardiac shunt. Dexmedetomidine pharmacokinetics may be influenced by age during the neonatal period, weight, total bypass time, and presence of intracardiac shunt. Dexmedetomidine clearance is significantly diminished in full-term newborns and increases rapidly in the first few weeks of life. The dependence of clearance on age during the first few weeks of life reflects the relative immaturity of metabolic processes during the newborn period. Continuous infusions of up to 0.3 μg/kg/h in neonates and 0.75 μg/kg/h in infants were well tolerated after open heart surgery.

Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

NASA Astrophysics Data System (ADS)

Baum, K.; Essfeld, D.; Stegemann, J.

To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

Influence of Transplant Center Procedural Volume on Survival Outcomes of Heart Transplantation for Children Bridged with Mechanical Circulatory Support.

PubMed

Hsieh, Alex; Tumin, Dmitry; McConnell, Patrick I; Galantowicz, Mark; Tobias, Joseph D; Hayes, Don

2017-02-01

Transplant center expertise improves survival after heart transplant (HTx) but it is unknown whether center expertise ameliorates risk associated with mechanical circulatory support (MCS) bridge to transplantation. This study investigated whether center HTx volume reduced survival disparities among pediatric HTx patients bridged with extracorporeal membrane oxygenation (ECMO), left ventricular assist device (LVAD), or no MCS. Patients ≤18 years of age receiving first-time HTx between 2005 and 2015 were identified in the United Network of Organ Sharing registry. Center volume was the total number of HTx during the study period, classified into tertiles. The primary outcome was 1 year post-transplant survival, and MCS type was interacted with center volume in Cox proportional hazards regression. The study cohort included 4131 patients, of whom 719 were supported with LVAD and 230 with ECMO. In small centers (≤133 HTx over study period), patients bridged with ECMO had increased post-transplant mortality hazard compared to patients bridged with LVAD (HR 0.29, 95% CI 0.12, 0.71; p = 0.006) and patients with no MCS (HR 0.33, 95% CI 0.19, 0.57; p < 0.001). Interactions of MCS type with medium or large center volume were not statistically significant, and the same differences in survival by MCS type were observed in medium- or large-volume centers (136-208 or ≥214 HTx over the study period). Post-HTx survival disadvantage of pediatric patients bridged with ECMO persisted regardless of transplant program volume. The role of institutional ECMO expertise outside the transplant setting for improving outcomes of ECMO bridge to HTx should be explored.

Quantitative assessment of paravalvular leakage after transcatheter aortic valve replacement using a patient-specific pulsatile flow model.

PubMed

Tanaka, Yutaka; Saito, Shigeru; Sasuga, Saeko; Takahashi, Azuma; Aoyama, Yusuke; Obama, Kazuto; Umezu, Mitsuo; Iwasaki, Kiyotaka

2018-05-01

Quantitative assessment of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR) remains challenging. We developed patient-specific anatomical models with pulsatile flow circuit and investigated factors associated with AR after TAVR. Based on pre-procedural computed tomography (CT) data of the six patients who underwent transfemoral TAVR using a 23-mm SAPIEN XT, anatomically and mechanically equivalent aortic valve models were developed. Forward flow and heart rate of each patient in two days after TAVR were duplicated under mean aortic pressure of 80mmHg. Paravalvular leakage (PVL) volume in basal and additional conditions was measured for each model using an electromagnetic flow sensor. Incompletely apposed tract between the transcatheter and aortic valves was examined using a micro-CT. PVL volume in each patient-specific model was consistent with each patient's PVL grade, and was affected by hemodynamic conditions. PVL and total regurgitation volume increased with the mean aortic pressure, whereas closing volume did not change. In contrast, closing volume increased proportionately with heart rate, but PVL did not change. The minimal cross-sectional gap had a positive correlation with the PVL volumes (r=0.89, P=0.02). The gap areas typically occurred in the vicinity of the bulky calcified nodules under the native commissure. PVL volume, which could be affected by hemodynamic conditions, was significantly associated with the minimal cross-sectional gap area between the aortic annulus and the stent frame. These data may improve our understanding of the mechanism of the occurrence of post-TAVR PVL. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Left atrial phasic function and heart rate variability in asymptomatic diabetic patients.

PubMed

Tadic, Marijana; Vukomanovic, Vladan; Cuspidi, Cesare; Suzic-Lazic, Jelena; Stanisavljevic, Dejana; Celic, Vera

2017-03-01

We evaluated left atrial (LA) phasic function and heart rate variability (HRV) in asymptomatic diabetic patients, and the relationship between HRV indices and LA phasic function assessed by volumes and speckle tracking imaging. This cross-sectional study included 55 asymptomatic patients with type 2 diabetes and 50 healthy controls without cardiovascular risk factors. All study subjects underwent laboratory analyses, complete two-dimensional echocardiography examination (2DE) and 24-h Holter monitoring. Maximum, minimum LA and pre-A LA volumes and volume indexes are significantly higher in diabetic patients. Total and passive LA emptying fractions (EF), representing the LA reservoir and conduit function, are significantly lower in diabetic subjects. Active LA EF, the parameter of the LA booster pump function, is compensatory increased in diabetic patients. Similar results were obtained by 2DE strain analysis. Cardiac autonomic function, assessed by HRV, is significantly deteriorated in diabetic patients. Time and frequency-domain HRV measures are significantly lower in diabetic subjects than in controls. HbA1c, LV mass index and HRV are associated with total LA EF and longitudinal LA strain independently of age, body mass index and LV diastolic function in the whole study population. LA phasic function and cardiac autonomic nervous system assessed by HRV are impacted by diabetes. HbA1c and HRV are independently associated with LA reservoir function evaluated by volumetric and strain methods in the whole study population. This study emphasizes the importance of determination of LA function and HRV as important markers of preclinical cardiac damage and autonomic function impairment in diabetic patients.

Use of tomotherapy in treatment of synchronous bilateral breast cancer: dosimetric comparison study

PubMed Central

Wadasadawala, T; Sarin, R; Upreti, R R; Paul, S; Phurailatpam, R

2015-01-01

Objective: Synchronous malignancy in both breasts is a rare incidence. The present study aims at dosimetric comparison of conventional bitangential radiotherapy (RT) technique with conventional [field-in-field (FIF)] and rotational [Helical TomoTherapy® and TomoDirect™ (TD); Accuray Inc., Sunnyvale, CA] intensity-modulated RT for patients with synchronous bilateral breast cancer (SBBC). Methods: CT data sets of 10 patients with SBBC were selected for the present study. RT was planned for all patients on both sides to whole breast and/or chest wall using the above-mentioned techniques. Six females with breast conservation on at least one side also had a composite plan along with tumour bed (TB) boost using sequential electrons for bitangential and FIF techniques or sequential helical tomotherapy (HT) boost (for TD) or simultaneous integrated boost (SIB) for HT. Results: All techniques produced acceptable target coverage. The hotspot was significantly lower with FIF technique and HT but higher with TD. For the organs at risk doses, HT resulted in significant reduction of the higher dose volumes. Similarly, TD resulted in significant reduction of the mean dose to the heart and total lung by reducing the lower dose volumes. All techniques of delivering boost to the TB were comparable in terms of target coverage. HT-SIB markedly reduced mean doses to the total lung and heart by specifically lowering the higher dose volumes. Conclusion: This study demonstrates the cardiac and pulmonary sparing ability of tomotherapy in the setting of SBBC. Advances in knowledge: This is the first study demonstrating feasibility of treatment of SBBC using tomotherapy. PMID:25605345

Current progress in the development of a totally implantable Gyro centrifugal artificial heart.

PubMed

Takami, Y; Ohtsuka, G; Mueller, J; Ebner, M; Tayama, E; Ohashi, Y; Taylor, D; Fernandes, J; Schima, H; Schmallegger, H; Wolner, E; Nosé, Y

1998-01-01

A totally implantable centrifugal artificial heart has been developed using a miniaturized pivot bearing supported centrifugal pump (Gyro PI pump). The authors report current progress in its development. The Gyro PI-601 has a priming volume of 20 ml, weighs 100 g, has a height of 60 mm, and has a diameter of 65 mm. This pump can provide 8 L/min against 150 mmHg at 2,250 rpm. It is driven by an miniaturized DC brushless motor with the coils fixed in a plastic mold that is waterproof and made of titanium (weight, 204 g; height, 18 mm; diameter, 65 mm). In this centrifugal artificial heart, two Gyro PI pumps are implanted independently to replace cardiac function without resecting the native heart. Its anatomic and surgical feasibility were confirmed experimentally. The Gyro PI-601 was implanted as a right or left ventricular assist device in the preperitoneal space of five calves. All five tests proceeded without any thromboembolic symptoms. One of five tests was extended more than 1 month to confirm the long-term feasibility of the Gyro PI-601 pump system. Based on the satisfactory results of the in vivo tests, the material conversion of the Gyro PI from polycarbonate to titanium alloy (Ti-6A1-4V) was undertaken to improve its biocompatibility for long-term implantation.

SU-F-T-204: A Preliminary Approach of Reducing Contralateral Breast and Heart Dose in Left Sided Whole Breast Cancer Patients Utilizing Proton Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Islam, M; Algan, O; Jin, H

Purpose: To investigate the plan quality and feasibility of a hybrid plan utilizing proton and photon fields for superior coverage in the internal mammary (IM) and supraclavicular (S/C) regions while minimizing heart and contralateral breast dose for the left-sided whole breast cancer patient treatment. Methods: This preliminary study carried out on single left-sided intact breast patient involved IM and S/C nodes. The IM and S/C node fields of the 5-Field 3DCRT photon-electron base plan were replaced by two proton fields. These two along with two Field-in-Field tangential photon fields were optimized for comparable dose coverage. The treatment plans were donemore » using Eclipse TPS for the total dose of 46Gy in 23 fractions with 95% of the prescription dose covering 95% of the RTOG PTV. The 3DCRT photon-electron and 4-Field photon-proton hybrid plans were compared for the PTV dose coverage as well as dose to OARs. Results: The overall RTOG PTV coverage for proton-hybrid and 3DCRT plan was comparable (95% of prescription dose covers 95% PTV volume). In proton-hybrid plan, 99% of IM volume received 100% dose whereas in 3DCRT only 77% received 100% dose. For S/C regions, 97% and 77% volume received 100% prescription dose in proton-hybrid and 3DCRT plans, respectively. The heart mean dose, V3Gy(%), and V5Gy(%) was 2.2Gy, 14.4%, 9.8% for proton-hybrid vs. 4.20 Gy, 21.5%, and 39% for 3DCRT plan, respectively. The maximum dose to the contralateral breast was 39.75Gy for proton-hybrid while 56.87Gy for 3DCRT plan. The mean total lung dose, V20Gy(%), and V30Gy(%) was 5.68Gy, 11.3%, 10.5% for proton-hybrid vs. 5.90Gy, 9.8%, 7.2% for 3DCRT, respectively. Conclusion: The protonhybrid plan can offer better dose coverage to the involved lymphatic tissues while lower doses to the heart and contralateral breast. More treatment plans are currently in progress before being implemented clinically.« less

Ivabradine and metoprolol differentially affect cardiac glucose metabolism despite similar heart rate reduction in a mouse model of dyslipidemia.

PubMed

Vaillant, Fanny; Lauzier, Benjamin; Ruiz, Matthieu; Shi, Yanfen; Lachance, Dominic; Rivard, Marie-Eve; Bolduc, Virginie; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine

2016-10-01

While heart rate reduction (HRR) is a target for the management of patients with heart disease, contradictory results were reported using ivabradine, which selectively inhibits the pacemaker I f current, vs. β-blockers like metoprolol. This study aimed at testing whether similar HRR with ivabradine vs. metoprolol differentially modulates cardiac energy substrate metabolism, a factor determinant for cardiac function, in a mouse model of dyslipidemia (hApoB +/+ ;LDLR -/- ). Following a longitudinal study design, we used 3- and 6-mo-old mice, untreated or treated for 3 mo with ivabradine or metoprolol. Cardiac function was evaluated in vivo and ex vivo in working hearts perfused with 13 C-labeled substrates to assess substrate fluxes through energy metabolic pathways. Compared with 3-mo-old, 6-mo-old dyslipidemic mice had similar cardiac hemodynamics in vivo but impaired (P < 0.001) contractile function (aortic flow: -45%; cardiac output: -34%; stroke volume: -35%) and glycolysis (-24%) ex vivo. Despite inducing a similar 10% HRR, ivabradine-treated hearts displayed significantly higher stroke volume values and glycolysis vs. their metoprolol-treated counterparts ex vivo, values for the ivabradine group being often not significantly different from 3-mo-old mice. Further analyses highlighted additional significant cardiac alterations with disease progression, namely in the total tissue level of proteins modified by O-linked N-acetylglucosamine (O-GlcNAc), whose formation is governed by glucose metabolism via the hexosamine biosynthetic pathway, which showed a similar pattern with ivabradine vs. metoprolol treatment. Collectively, our results emphasize the implication of alterations in cardiac glucose metabolism and signaling linked to disease progression in our mouse model. Despite similar HRR, ivabradine, but not metoprolol, preserved cardiac function and glucose metabolism during disease progression. Copyright © 2016 the American Physiological Society.

Heart disease and left ventricular rotation - a systematic review and quantitative summary.

PubMed

Phillips, Aaron A; Cote, Anita T; Bredin, Shannon S D; Warburton, Darren E R

2012-06-24

Left ventricular (LV) rotation is increasingly examined in those with heart disease. The available evidence measuring LV rotation in those with heart diseases has not been systematically reviewed. To review systematically the evidence measuring LV rotational changes in various heart diseases compared to healthy controls, literature searches were conducted for appropriate articles using several electronic databases (e.g., MEDLINE, EMBASE). All randomized-controlled trials, prospective cohort and case-controlled studies that assessed LV rotation in relation to various heart conditions were included. Three independent reviewers evaluated each investigation's quality using validated scales. Results were tabulated and levels of evidence assigned. A total of 1,782 studies were found through the systematic literature search. Upon review of the articles, 47 were included. The articles were separated into those investigating changes in LV rotation in participants with: aortic stenosis, myocardial infarction, hypertrophic cardiomyopathy, dilated cardiomyopathy, non-compaction, restrictive cardiomyopathy/ constrictive pericarditis, heart failure, diastolic dysfunction, heart transplant, implanted pacemaker, coronary artery disease and cardiovascular disease risk factors. Evidence showing changes in LV rotation due to various types of heart disease was supported by evidence with limited to moderate methodological quality. Despite a relatively low quality and volume of evidence, the literature consistently shows that heart disease leads to marked changes in LV rotation, while rotational systolic-diastolic coupling is preserved. No prognostic information exists on the potential value of rotational measures of LV function. The literature suggests that measures of LV rotation may aid in diagnosing subclinical aortic stenosis and diastolic dysfunction.

Evolving trends in aortic valve replacement: A statewide experience.

PubMed

Kim, Karen M; Shannon, Francis; Paone, Gaetano; Lall, Shelly; Batra, Sanjay; Boeve, Theodore; DeLucia, Alphonse; Patel, Himanshu J; Theurer, Patricia F; He, Chang; Clark, Melissa J; Sultan, Ibrahim; Deeb, George Michael; Prager, Richard L

2018-06-17

Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) for the treatment of aortic stenosis in patients at intermediate, high, and extreme risk for mortality from SAVR. We examined recent trends in aortic valve replacement (AVR) in Michigan. The Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative (MSTCVS-QC) database was used to determine the number of SAVR and TAVR cases performed from January 2012 through June 2017. Patients were divided into low, intermediate, high, and extreme risk groups based on STS predicted risk of mortality (PROM). TAVR patients in the MSTCVS-QC database were also matched with those in the Transcatheter Valve Therapy Registry to determine their Heart Team-designated risk category. During the study period 9517 SAVR and 4470 TAVR cases were performed. Total annual AVR volume increased by 40.0% (from 2086 to 2920), with a 13.3% decrease in number of SAVR cases (from 1892 to 1640) and a 560% increase in number of TAVR cases (from 194 to 1280). Greater than 90% of SAVR patients had PROM ≤8%. While >70% of TAVR patients had PROM ≤ 8%, they were mostly designated as high or extreme risk by a Heart Team. During the study period, SAVR volume gradually declined and TAVR volume dramatically increased. This was mostly due to a new group of patients with lower STS PROM who were designated as higher risk by a Heart Team due to characteristics not completely captured by the STS PROM score. © 2018 Wiley Periodicals, Inc.

Total heart replacement using dual intracorporeal continuous-flow pumps in a chronic bovine model: a feasibility study.

PubMed

Frazier, O H; Tuzun, Egemen; Cohn, William E; Conger, Jeffrey L; Kadipasaoglu, Kamuran A

2006-01-01

Continuous-flow pumps are small, simple, and respond physiologically to input variations, making them potentially ideal for total heart replacement. However, the physiological effects of complete pulseless flow during long-term circulatory support without a cardiac interface or with complete cardiac exclusion have not been well studied. We evaluated the feasibility of dual continuous-flow pumps as a total artificial heart (TAH) in a chronic bovine model. Both ventricles of a 6-month-old Corriente crossbred calf were excised and sewing rings attached to the reinforced atrioventricular junctions. The inlet portions of 2 Jarvik 2000 pumps were positioned through their respective sewing rings at the mid-atrial level and the pulseless atrial reservoir connected end-to-end to the pulmonary artery and aorta. Pulseless systemic and pulmonary circulations were thereby achieved. Volume status was controlled, and systemic and pulmonary resistance were managed pharmacologically to keep mean arterial pressures at 100+/-10 mmHg (systemic) and 20+/-5 mmHg (pulmonary) and both left and right atrial pressures at 15+/-5 mmHg. The left pump speed was maintained at 14,000 rpm and its output autoregulated in response to variations in right pump flow, systemic and pulmonary pressures, fluid status, and activity level. Hemodynamics, end-organ function, and neurohormonal status remained normal. These results suggest the feasibility of using dual continuous-flow pumps as a TAH.

Comparison of cardiovascular function during the early hours of bed rest and space flight

NASA Technical Reports Server (NTRS)

Lathers, C. M.; Charles, J. B.

1994-01-01

This paper reviews the cardiovascular responses of six healthy male subjects to 6 hours in a 5 degrees head-down bed rest model of weightlessness, and compares these responses to those obtained when subjects were positioned in head-up tilts of 10 degrees, 20 degrees, and 42 degrees, simulating 1/6, 1/3, and 2/3 G, respectively. Thoracic fluid index, cardiac output, stroke volume, and peak flow were measured using impedance cardiography. Cardiac dimensions and volumes were determined from two-dimensional guided M-mode echocardiograms in the left lateral decubitus position at 0, 2, 4, and 6 hours. Cardiovascular response to a stand test were compared before and after bed rest. The impedance values were related to tilt angle for the first 2 hours of tilt; however, after 3 hours, at all four angles, values began to converge, indicating that cardiovascular homeostatic mechanisms seek a common adapted state, regardless of effective gravity level (tilt angle) up to 2/3 G. Echocardiography revealed that left ventricular end-diastolic and end-systolic volume, stroke volume, ejection fraction, heart rate, and cardiac output had returned to control values by hour 6 for all tilt angles. The lack of a significant immediate change in left ventricular end-diastolic volume, despite decrements in stroke volume (P < .05) and heart rate (not significant), indicates that multiple factors may play a role in the adaptation to simulated hypogravity. The echocardiography data indicated that no angle of tilt, whether head-down or head-up for 4 to 6 hours, mimicked exactly the changes in cardiovascular function recorded after 4 to 6 hours of space flight. Changes in left ventricular end-diastolic volume during space flight and tilt may be similar, but follow a different time course. Nevertheless, head-down tilt at 5 degrees for 6 hours mimics some (stroke volume, systolic and diastolic blood pressure, mean arterial blood pressure, and total resistance), but not all, of the changes occurring in an equivalent time of space flight. The magnitude of the change in the mean heart rate response to standing was greater after six hours of tilt at -5 degrees or 10 degrees. Thus, results from the stand test after 6 hours of bed rest at -5 degrees and 10 degrees, but not at 20 degrees or 42 degrees, are similar to those obtained after space flight.

[Diagnostic and treatment characteristics of ischemic heart disease patients with asynergies].

PubMed

Furkalo, N K; Lutaĭ, M I; Zaĭtseva, V I

1985-01-01

A total of 64 patients with coronary heart disease were examined using contrast coronaro-ventriculography, veloergometry and estimation of the lactic acid level in the coronary sinus blood. Fifty-seven patients were referred to obsidan therapy by the "blind" method. Two groups of patients with asynergies of ischemic and cicatricial genesis were singled out. The sensitivity of the ST segment depression and sigma R increment as objective signs of ischemia significantly reduced in the presence of postinfarction cardiosclerosis. Obsidan monotherapy caused a rise of load power and volume of work performed in the patients with asynergies of ischemic origin: an antianginal effect of the drug in such cases was comparable to that in the patients without disturbed myocardial regional cantractility.

Long-term exposure to fine particulate matter, residential proximity to major roads and measures of brain structure.

PubMed

Wilker, Elissa H; Preis, Sarah R; Beiser, Alexa S; Wolf, Philip A; Au, Rhoda; Kloog, Itai; Li, Wenyuan; Schwartz, Joel; Koutrakis, Petros; DeCarli, Charles; Seshadri, Sudha; Mittleman, Murray A

2015-05-01

Long-term exposure to ambient air pollution is associated with cerebrovascular disease and cognitive impairment, but whether it is related to structural changes in the brain is not clear. We examined the associations between residential long-term exposure to ambient air pollution and markers of brain aging using magnetic resonance imaging. Framingham Offspring Study participants who attended the seventh examination were at least 60 years old and free of dementia and stroke were included. We evaluated associations between exposures (fine particulate matter [PM2.5] and residential proximity to major roadways) and measures of total cerebral brain volume, hippocampal volume, white matter hyperintensity volume (log-transformed and extensive white matter hyperintensity volume for age), and covert brain infarcts. Models were adjusted for age, clinical covariates, indicators of socioeconomic position, and temporal trends. A 2-μg/m(3) increase in PM2.5 was associated with -0.32% (95% confidence interval, -0.59 to -0.05) smaller total cerebral brain volume and 1.46 (95% confidence interval, 1.10 to 1.94) higher odds of covert brain infarcts. Living further away from a major roadway was associated with 0.10 (95% confidence interval, 0.01 to 0.19) greater log-transformed white matter hyperintensity volume for an interquartile range difference in distance, but no clear pattern of association was observed for extensive white matter. Exposure to elevated levels of PM2.5 was associated with smaller total cerebral brain volume, a marker of age-associated brain atrophy, and with higher odds of covert brain infarcts. These findings suggest that air pollution is associated with insidious effects on structural brain aging even in dementia- and stroke-free persons. © 2015 American Heart Association, Inc.

Preharvest application of oxalic acid increased fruit size, bioactive compounds, and antioxidant capacity in sweet cherry cultivars (Prunus avium L.).

PubMed

Martínez-Esplá, Alejandra; Zapata, Pedro Javier; Valero, Daniel; García-Viguera, Cristina; Castillo, Salvador; Serrano, María

2014-04-16

Trees of 'Sweet Heart' and 'Sweet Late' sweet cherry cultivars (Prunus avium L.) were treated with oxalic acid (OA) at 0.5, 1.0, and 2.0 mM at 98, 112, and 126 days after full blossom. Results showed that all treatments increased fruit size at harvest, manifested by higher fruit volume and weight in cherries from treated trees than from controls, the higher effect being found with 2.0 mM OA (18 and 30% higher weight for 'Sweet Heart' and 'Sweet Late', respectively). Other quality parameters, such as color and firmness, were also increased by OA treatments, although no significant differences were found in total soluble solids or total acidity, showing that OA treatments did not affect the on-tree ripening process of sweet cherry. However, the increases in total anthocyanins, total phenolics, and antioxidant activity associated with the ripening process were higher in treated than in control cherries, leading to fruit with high bioactive compounds and antioxidant potential at commercial harvest (≅45% more anthocyanins and ≅20% more total phenolics). In addition, individual anthocyanins, flavonols, and chlorogenic acid derivatives were also increased by OA treatment. Thus, OA preharvest treatments could be an efficient and natural way to increase the quality and functional properties of sweet cherries.

[Association of human epicardial adipose tissue volume and inflammatory mediators with atherosclerosis and vulnerable coronary atherosclerotic plaque].

PubMed

Zhou, Liangliang; Gong, Jianbin; Li, Demin; Lu, Guangming; Chen, Dong; Wang, Jing

2015-02-01

To investigate the relation of epicardial adipose tissue volume (EATV) determined by dual-source CT (DSCT) cardiac angiography and EAT-derived inflammatory factors to coronary heart disease (CHD) and vulnerable plaque. A total of 260 patients underwent cardiac computed tomography to evaluate stenosis of coronary artery, and blood samples were obtained from each patient. CHD was confirmed in 180 patients by DSA and CHD was excluded in the remaining 80 patients (NCHD). Vascular remodeling index and plaque vulnerability parameters (fatty volume, fibrous volume and calcification volume and fiber volume) were measured in CHD patients and correlation with EATV was analyzed. Epicardial adipose tissue (EAT) and intrathoracic adipose tissue (TAT) were collected from 40 CHD patients undergoing CABG surgery, and, mRNA and protein expressions of leptin and MMP9 were detected by RT-PCR and Western blot analysis. (1) The EATV was significantly higher in the CHD group than in NCHD group ((121.2 ± 40.6) mm³ vs. (74.7 ± 18.1) mm³, P = 0.01). (2) Subgroup analysis of the CHD patients demonstrated that EATV was significantly higher in patients with positive remodeling than in patients without positive remodeling ((97.6 ± 42.0) cm³ vs. (75.5 ± 25.4) cm³, P = 0.01). Lipid plaque volume was positively correlated with EATV (r = 0.34, P = 0.002); however, fiber plaque volume was negatively correlated with EATV (r = -0.30, P = 0.008). (3) Logistic regression analysis indicated that EATV was an independent risk factor for positive vascular remodeling (OR = 2.01, 95% CI: 1.30-2.32, P = 0.01). (4) mRNA and protein expression of leptin and MMP9 in EAT was significantly upregulated in 40 CHD patients who received CABG surgery compared to 40 NCHD patients (P < 0.01). However, there was no significant difference (P > 0.05) in mRNA and protein expression of leptin and MMP9 from the SAT between CHD and NCHD patients. (5) In the CHD group, leptin and MMP9 levels in EAT and EATV were positively correlated with lipid plaque volume and fibrous plaque volume (P < 0.05). EATV is an independent risk factors of coronary heart disease and plaque vulnerability; EAT secretion of inflammatory cytokines from CHD patients is significant increased compared to NCHD patients, EAT secretion of inflammatory cytokines are positively correlated with EATV, both of which are determinants affecting vascular remodeling. Reducing EATV might help to attenuate inflammation and plaque vulnerability and reduce the risk of coronary heart disease.

Feasibility of intensity-modulated radiotherapy for esophageal cancer in definite chemoradiotherapy.

PubMed

Hsieh, He-Yuan; Yeh, Hui-Ling; Hsu, Chung-Ping; Lin, Jin-Ching; Chuang, Cheng-Yen; Lin, Jai-Fu; Chang, Chen-Fa

2016-07-01

Esophageal cancer is a highly lethal malignancy, and its treatment has undergone a major evolution over the past 15 years. The objective of this study was to report our experience on the efficacy of definite chemoradiotherapy with the intensity-modulated radiotherapy (IMRT) technique in treating locally advanced esophageal cancer. From September 2004 to November 2011, 39 patients with biopsy-proven esophageal cancer, clinical stage T1-4N0-3M0 according to the American Joint Committee on Cancer 7(th) edition were enrolled. In these enrolled cases, either the tumor was unresectable or the patients refused surgery. All patients received a total radiation dose of 40-56 Gy in 20-28 fractions using IMRT planning. Five to seven radiation beam angles were designed according to the specific shape of the clinical target volume (CTV) and were delivered by a linear accelerator with photons of 6-10 MV energy. The gross tumor volume, CTV, planning target volume, and the organs at risk were outlined, and the homogeneity index (HI) and the conformity index (CI) were calculated. The treatment-related toxicities were also reviewed. The mean follow-up time was 22.4 months (range, 2.0-91.0 months). The 2- and 3-year overall survival rates were 30% and 28%, respectively. The most common Grade 3/4 toxicity was hematologic toxicity (43.6%). The IMRT plans showed high-dose homogeneity to the target, with a calculated HI of 0.9. The calculated CI of 0.8 also showed high conformity treatment dose to target within an acceptable dose range. For the total lungs, the average mean dose was 1313.7 cGy. The V5 and V20 of the total lungs were 67.8% and 23.4%, respectively. For the heart, the average mean dose was 2319.2 cGy. The V30 and V35 of the heart were 30.2% and 21.5%, respectively. Concurrent chemoradiotherapy using the IMRT technique for treating locally advanced unresectable esophageal cancer is feasible, with better conformity of target volume as well as improved sparing of organs at risk. Copyright © 2016. Published by Elsevier Taiwan LLC.

Vertebrate blood cell volume increases with temperature: implications for aerobic activity.

PubMed

Gillooly, James F; Zenil-Ferguson, Rosana

2014-01-01

Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures.

DVH- and NTCP-based dosimetric comparison of different longitudinal margins for VMAT-IMRT of esophageal cancer.

PubMed

Münch, S; Oechsner, M; Combs, S E; Habermehl, D

2017-08-15

To cover the microscopic tumor spread in squamous cell carcinoma of the esophagus (SCC), longitudinal margins of 3-4 cm are used for radiotherapy (RT) protocols. However, smaller margins of 2-3 cm might be reasonable when advanced diagnostic imaging is integrated into target volume delineation. Purpose of this study was to compare the dose distribution and deposition to the organs at risk (OAR) for different longitudinal margins using a DVH- and NTCP-based approach. Ten patients with SCC of the middle or lower third were retrospectively selected. Three planning target volumes (PTV) with longitudinal margins of 4 cm, 3 cm and 2 cm and an axial margin of 1.5 cm to the gross target volume (GTV) were defined for each patient. For each PTV two treatment plans with total doses of 41.4 Gy (neoadjuvant treatment) and 50.4 Gy (definite treatment) were calculated. Dose to the lungs, heart, myelon and liver were then evaluated and compared between different PTVs. When using a longitudinal margin of 3 cm instead of 4 cm, all dose parameters (Dmin, Dmean, Dmedian and V5-V35), except Dmax could be significantly reduced for the lungs. Regarding the heart, a significant reduction was seen for Dmean and V5, but not for Dmin, Dmax, Dmedian and V10-V35. When comparing a longitudinal margin of 4 cm to a longitudinal margin of 2 cm, a significant difference was calculated for Dmin, Dmean, Dmedian and V5-V35 of the lungs and for Dmax, Dmean and V5-V35 of the heart. Nevertheless, no difference was seen for median heart dose. An additional dose reduction for V10 of the heart was achieved for definite treatment plans when using a longitudinal margin of 3 cm. The NTCP-based risk of pneumonitis was significantly reduced by a margin reduction to 2 cm for neoadjuvant and definite treatment plans. Reduction of longitudinal margins from 4 cm to 3 cm can significantly reduce the dose to lungs and Dmean of the heart. Despite clinical benefit and oncologic outcome remain unclear, reduction of the longitudinal margins might provide the opportunity to reduce side effects of chemoradiation (CRT) for SCC in upcoming studies.

Accurate computer-aided quantification of left ventricular parameters: experience in 1555 cardiac magnetic resonance studies from the Framingham Heart Study.

PubMed

Hautvast, Gilion L T F; Salton, Carol J; Chuang, Michael L; Breeuwer, Marcel; O'Donnell, Christopher J; Manning, Warren J

2012-05-01

Quantitative analysis of short-axis functional cardiac magnetic resonance images can be performed using automatic contour detection methods. The resulting myocardial contours must be reviewed and possibly corrected, which can be time-consuming, particularly when performed across all cardiac phases. We quantified the impact of manual contour corrections on both analysis time and quantitative measurements obtained from left ventricular short-axis cine images acquired from 1555 participants of the Framingham Heart Study Offspring cohort using computer-aided contour detection methods. The total analysis time for a single case was 7.6 ± 1.7 min for an average of 221 ± 36 myocardial contours per participant. This included 4.8 ± 1.6 min for manual contour correction of 2% of all automatically detected endocardial contours and 8% of all automatically detected epicardial contours. However, the impact of these corrections on global left ventricular parameters was limited, introducing differences of 0.4 ± 4.1 mL for end-diastolic volume, -0.3 ± 2.9 mL for end-systolic volume, 0.7 ± 3.1 mL for stroke volume, and 0.3 ± 1.8% for ejection fraction. We conclude that left ventricular functional parameters can be obtained under 5 min from short-axis functional cardiac magnetic resonance images using automatic contour detection methods. Manual correction more than doubles analysis time, with minimal impact on left ventricular volumes and ejection fraction. Copyright © 2011 Wiley Periodicals, Inc.

Heart dose exposure as prognostic marker after radiotherapy for resectable stage IIIA/B non-small-cell lung cancer: secondary analysis of a randomized trial.

PubMed

Guberina, M; Eberhardt, W; Stuschke, M; Gauler, T; Heinzelmann, F; Cheufou, D; Kimmich, M; Friedel, G; Schmidberger, H; Darwiche, K; Jendrossek, V; Schuler, M; Stamatis, G; Pöttgen, C

2017-05-01

Heart exposure to ionizing irradiation can cause ischaemic heart disease. The partial heart volume receiving ≥5 Gy (heartV5) was supposed to be an independent prognostic factor for survival after radiochemotherapy for locally advanced non-small-cell lung cancer (NSCLC). But validation of the latter hypothesis is needed under the concurrent risks of lung cancer patients. The ESPATUE phase III trial recruited patients with potentially operable IIIA(N2)/selected IIIB NSCLC between 01/2004 and 01/2013. Cisplatin/paclitaxel induction chemotherapy was given followed by neoadjuvant radiochemotherapy (RT/CT) to 45 Gy (1.5 Gy bid/concurrent cisplatin/vinorelbine). Operable patients were randomized to definitive RT/CT(arm A) or surgery (arm B) and therefore were treated at two different total dose levels of radiotherapy. HeartV5 and mean heart dose (MHD) were obtained from the 3D radiotherapy plans, the prognostic value was analysed using multivariable proportional hazard analysis. A total of 161 patients were randomized in ESPATUE, heartV5 and MHD were obtained from the 3D radiotherapy plans for 155 of these [male/female:105/50, median age 58 (33-74) years, stage IIIA/IIIB: 54/101]. Power analysis revealed a power of 80% of this dataset to detect a prognostic value of heartV5 of the size found in RTOG 0617. Multivariable analysis did not identify heartV5 as an independent prognostic factor for survival adjusting for tumour and clinical characteristics with [hazard ratio 1.005 (0.995-1.015), P = 0.30] or without lower lobe tumour location [hazard ratio 0.999 (0.986-1.012), P = 0.83]. There was no influence of heartV5 on death without tumour progression. Tumour progression, and pneumonia were the leading causes of death representing 65% and 14% of the observed deaths. HeartV5 could not be validated as an independent prognostic factor for survival after neoadjuvant or definitive conformal radiochemotherapy. Tumour progression was the predominant cause of death. Z5 - 22461/2 - 2002-017 (German Federal Office for Radiation Protection). © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Instantaneous stroke volume by PDE during and after constant LBNP (-50 torr)

NASA Technical Reports Server (NTRS)

1980-01-01

Six male subjects were exposed to -50 torr lower body negative pressure (LBNP) for 10 min while stroke volume was recorded beat by beat at regular intervals before, during and after release of LBNP. Stroke volume was calculated from the systolic velocity integral in the ascending aorta by pulsed Doppler echocardiography (PDE) and the cross sectional area of the vessel by M mode echocardiography. Changes in leg volume were recorded continuously and blood pressure was taken every minute. Stroke volume dropped by 51% of the control in the first 33 sec of LBNP and continued to decline slowly to -62% toward the end. Heart rate increased by 15% in the first 10 sec and was 22% above control at the end of exposure. The resulting cardiac output closely followed the course of stroke volume (-47% at 33 sec, -53% at 8 min) showing that the modest increase in heart rate did little to offset the drop in stroke volume. Leg volume increased markedly within the first 10 sec with a more gradual rise reaching +3.5% at the end. Upon sudden release of LBNP, leg volume dropped significantly during the first 3 sec simultaneously with an increase in stroke volume followed by a substantial decline in heart rate below the baseline.

Lung Function before and Two Days after Open-Heart Surgery.

PubMed

Urell, Charlotte; Westerdahl, Elisabeth; Hedenström, Hans; Janson, Christer; Emtner, Margareta

2012-01-01

Reduced lung volumes and atelectasis are common after open-heart surgery, and pronounced restrictive lung volume impairment has been found. The aim of this study was to investigate factors influencing lung volumes on the second postoperative day. Open-heart surgery patients (n = 107, 68 yrs, 80% male) performed spirometry both before surgery and on the second postoperative day. The factors influencing postoperative lung volumes and decrease in lung volumes were investigated with univariate and multivariate analyses. Associations between pain (measured by numeric rating scale) and decrease in postoperative lung volumes were calculated with Spearman rank correlation test. Lung volumes decreased by 50% and were less than 40% of the predictive values postoperatively. Patients with BMI >25 had lower postoperative inspiratory capacity (IC) (33 ± 14% pred.) than normal-weight patients (39 ± 15% pred.), (P = 0.04). More pain during mobilisation was associated with higher decreases in postoperative lung volumes (VC: r = 0.33, P = 0.001; FEV(1): r = 0.35, P ≤ 0.0001; IC: r = 0.25, P = 0.01). Patients with high BMI are a risk group for decreased postoperative lung volumes and should therefore receive extra attention during postoperative care. As pain is related to a larger decrease in postoperative lung volumes, optimal pain relief for the patients should be identified.

Lung Function before and Two Days after Open-Heart Surgery

PubMed Central

Urell, Charlotte; Westerdahl, Elisabeth; Hedenström, Hans; Janson, Christer; Emtner, Margareta

2012-01-01

Reduced lung volumes and atelectasis are common after open-heart surgery, and pronounced restrictive lung volume impairment has been found. The aim of this study was to investigate factors influencing lung volumes on the second postoperative day. Open-heart surgery patients (n = 107, 68 yrs, 80% male) performed spirometry both before surgery and on the second postoperative day. The factors influencing postoperative lung volumes and decrease in lung volumes were investigated with univariate and multivariate analyses. Associations between pain (measured by numeric rating scale) and decrease in postoperative lung volumes were calculated with Spearman rank correlation test. Lung volumes decreased by 50% and were less than 40% of the predictive values postoperatively. Patients with BMI >25 had lower postoperative inspiratory capacity (IC) (33 ± 14% pred.) than normal-weight patients (39 ± 15% pred.), (P = 0.04). More pain during mobilisation was associated with higher decreases in postoperative lung volumes (VC: r = 0.33, P = 0.001; FEV1: r = 0.35, P ≤ 0.0001; IC: r = 0.25, P = 0.01). Patients with high BMI are a risk group for decreased postoperative lung volumes and should therefore receive extra attention during postoperative care. As pain is related to a larger decrease in postoperative lung volumes, optimal pain relief for the patients should be identified. PMID:22924127

A comparison of hydration effect on body fluid and temperature regulation between Malaysian and Japanese males exercising at mild dehydration in humid heat.

PubMed

Wakabayashi, Hitoshi; Wijayanto, Titis; Lee, Joo-Young; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

2014-02-04

This study investigated the effect of hydration differences on body fluid and temperature regulation between tropical and temperate indigenes exercising in the heat. Ten Japanese and ten Malaysian males with matched physical characteristics (height, body weight, and peak oxygen consumption) participated in this study. Participants performed exercise for 60 min at 55% peak oxygen uptake followed by a 30-min recovery at 32°C and 70% relative air humidity with hydration (4 times each, 3 mL per kg body weight, 37°C) or without hydration. Rectal temperature, skin temperature, heart rate, skin blood flow, and blood pressure were measured continuously. The percentage of body weight loss and total sweat loss were calculated from body weight measurements. The percentage change in plasma volume was estimated from hemoglobin concentration and hematocrit. Malaysian participants had a significantly lower rectal temperature, a smaller reduction in plasma volume, and a lower heart rate in the hydrated condition than in the non-hydrated condition at the end of exercise (P <0.05), whereas Japanese participants showed no difference between the two hydration conditions. Hydration induced a greater total sweat loss in both groups (P <0.05), and the percentage of body weight loss in hydrated Malaysians was significantly less than in hydrated Japanese (P <0.05). A significant interaction between groups and hydration conditions was observed for the percentage of mean cutaneous vascular conductance during exercise relative to baseline (P <0.05). The smaller reduction in plasma volume and percentage body weight loss in hydrated Malaysians indicated an advantage in body fluid regulation. This may enable Malaysians to reserve more blood for circulation and heat dissipation and thereby maintain lower rectal temperatures in a hydrated condition.

Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy.

PubMed

Goo, Hyun Woo; Park, Sang Hyub

2017-11-01

Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy.

Heart Disease and Left Ventricular Rotation – A Systematic Review and Quantitative Summary

PubMed Central

2012-01-01

Background Left ventricular (LV) rotation is increasingly examined in those with heart disease. The available evidence measuring LV rotation in those with heart diseases has not been systematically reviewed. Methods To review systematically the evidence measuring LV rotational changes in various heart diseases compared to healthy controls, literature searches were conducted for appropriate articles using several electronic databases (e.g., MEDLINE, EMBASE). All randomized-controlled trials, prospective cohort and case–controlled studies that assessed LV rotation in relation to various heart conditions were included. Three independent reviewers evaluated each investigation’s quality using validated scales. Results were tabulated and levels of evidence assigned. Results A total of 1,782 studies were found through the systematic literature search. Upon review of the articles, 47 were included. The articles were separated into those investigating changes in LV rotation in participants with: aortic stenosis, myocardial infarction, hypertrophic cardiomyopathy, dilated cardiomyopathy, non-compaction, restrictive cardiomyopathy/ constrictive pericarditis, heart failure, diastolic dysfunction, heart transplant, implanted pacemaker, coronary artery disease and cardiovascular disease risk factors. Evidence showing changes in LV rotation due to various types of heart disease was supported by evidence with limited to moderate methodological quality. Conclusions Despite a relatively low quality and volume of evidence, the literature consistently shows that heart disease leads to marked changes in LV rotation, while rotational systolic-diastolic coupling is preserved. No prognostic information exists on the potential value of rotational measures of LV function. The literature suggests that measures of LV rotation may aid in diagnosing subclinical aortic stenosis and diastolic dysfunction. PMID:22726250

Natural selection to sports, later physical activity habits, and coronary heart disease

PubMed Central

Kujala, U.; Sarna, S.; Kaprio, J.; Tikkanen, H.; Koskenvuo, M.

2000-01-01

Objectives—To investigate the associations between natural selection to sports at a young age, continuity of physical activity, and occurrence of coronary heart disease. Design—Prospective cohort study. Setting—Finland. Participants—Former top level male athletes participating at a young age (1920–1965) in different types of sport (endurance (n = 166), power speed (n = 235), "other" (n = 834)) and controls healthy at the age of 20 years (n = 743). Main outcome measures—Data on the occurrence of coronary heart disease were obtained from death certificates, three nationwide registers, and questionnaire studies in 1985 and 1995, and data on later physical activity were obtained from the questionnaires. Results—In 1985 all groups of former athletes were more physically active than controls (p<0.001). Despite similar total volumes of physical activity, compared with power speed athletes, former endurance athletes participated more often in vigorous activity (p = 0.006) and had less coronary heart disease (adjusted odds ratio 0.34, 95% confidence interval 0.17 to 0.73; p = 0.004). In 1985 and 1995, both endurance and other athletes had less coronary heart disease than controls. From 1986 to 1995, the incidence of new coronary heart disease was lower among those who participated in vigorous physical activity in 1985. Conclusions—Both a previous aptitude for endurance athletic events and continuity of vigorous physical activity seem to be associated with protection against coronary heart disease, but an aptitude for power speed events does not give protection against coronary heart disease. Key Words: coronary heart disease; fitness; genetic selection; physical activity PMID:11131233

Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure.

PubMed

Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

2015-05-01

Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): -2.65 to -0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = -0.25 mg/dL; 95% CI: -0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64-1.56; p = 0.993). Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed.

Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure

PubMed Central

Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

2015-01-01

Introduction Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. Objective The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. Methods MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. Results A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): −2.65 to −0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = −0.25 mg/dL; 95% CI: −0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64–1.56; p = 0.993). Conclusion Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed. PMID:25626761

Cardiovascular risk factors are associated with increased lesion burden and brain atrophy in multiple sclerosis.

PubMed

Kappus, Natalie; Weinstock-Guttman, Bianca; Hagemeier, Jesper; Kennedy, Cheryl; Melia, Rebecca; Carl, Ellen; Ramasamy, Deepa P; Cherneva, Mariya; Durfee, Jacqueline; Bergsland, Niels; Dwyer, Michael G; Kolb, Channa; Hojnacki, David; Ramanathan, Murali; Zivadinov, Robert

2016-02-01

Cardiovascular (CV) risk factors have been associated with changes in clinical outcomes in patients with multiple sclerosis (MS). To investigate the frequency of CV risks in patients with MS and their association with MRI outcomes. In a prospective study, 326 patients with relapsing-remitting MS and 163 patients with progressive MS, 61 patients with clinically isolated syndrome (CIS) and 175 healthy controls (HCs) were screened for CV risks and scanned on a 3T MRI scanner. Examined CV risks included hypertension, heart disease, smoking, overweight/obesity and type 1 diabetes. MRI measures assessed lesion volumes (LVs) and brain atrophy. Association between individual or multiple CV risks and MRI outcomes was examined adjusting for age, sex, race, disease duration and treatment status. Patients with MS showed increased frequency of smoking (51.7% vs 36.5%, p = 0.001) and hypertension (33.9% vs 24.7%, p=0.035) compared with HCs. In total, 49.9% of patients with MS and 36% of HCs showed ≥ 2 CV risks (p = 0.003), while the frequency of ≥ 3 CV risks was 18.8% in the MS group and 8.6% in the HCs group (p = 0.002). In patients with MS, hypertension and heart disease were associated with decreased grey matter (GM) and cortical volumes (p < 0.05), while overweight/obesity was associated with increased T1-LV (p < 0.39) and smoking with decreased whole brain volume (p = 0.049). Increased lateral ventricle volume was associated with heart disease (p = 0.029) in CIS. Patients with MS with one or more CV risks showed increased lesion burden and more advanced brain atrophy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Cardiac and Carotid Markers Link With Accelerated Brain Atrophy: The AGES-Reykjavik Study (Age, Gene/Environment Susceptibility-Reykjavik).

PubMed

Sabayan, Behnam; van Buchem, Mark A; Sigurdsson, Sigurdur; Zhang, Qian; Meirelles, Osorio; Harris, Tamara B; Gudnason, Vilmundur; Arai, Andrew E; Launer, Lenore J

2016-11-01

Pathologies in the heart-brain axis might, independently or in combination, accelerate the process of brain parenchymal loss. We aimed to investigate the association of serum N-terminal brain natriuretic peptide (NT-proBNP), as a marker of cardiac dysfunction, and carotid intima media thickness (CIMT), as a marker of carotid atherosclerosis burden, with structural brain changes. In the longitudinal population-based AGES-Reykjavik study (Age, Gene/Environment Susceptibility-Reykjavik), we included 2430 subjects (mean age, 74.6 years; 41.4% men) with baseline data on NT-proBNP and CITM (assessed by ultrasound imaging). Participants underwent a high-resolution brain magnetic resonance imaging at baseline and 5 years later to assess total brain (TBV), gray matter, and white matter volumes. Each unit higher log-transformed NT-proBNP was associated with 3.6 mL (95% confidence interval [CI], -6.0 to -1.1) decline in TBV and 3.5 mL (95% CI, -5.7 to -1.3) decline in gray matter volume. Likewise, each millimeter higher CIMT was associated with 10.8 mL (95% CI, -17.3 to -4.2) decline in TBV and 8.6 mL (95% CI, -14.4 to -2.8) decline in gray matter volume. There was no association between NT-proBNP and CIMT and changes in white matter volume. Compared with participants with low NT-proBNP and CIMT, participants with both high NT-proBNP and CIMT had 3.8 mL (95% CI, -6.0 to -1.6) greater decline in their TBV and 4 mL (95% CI, -6.0 to -2.0) greater decline in GMW. These associations were independent of sociodemographic and cardiovascular factors. Older subjects with both cardiac dysfunction and carotid atherosclerosis are at an increased risk for brain parenchymal loss. Accumulated pathologies in the heart-brain axis might accelerate brain atrophy. © 2016 American Heart Association, Inc.

[Role of hemodynamic factors and heart volume in the prognosis of acute cardiac insufficiency during the early postoperative period in patients with mitral valve stenosis].

PubMed

Guliamov, D S; Amanov, A A; Andres, Iu P; Bazhenova, T F

1983-07-01

Investigations performed in 172 patients have shown that the state of the myocardium (such parameters as the heart volume, degree of lung hypertension, end-diastolic pressure in the right and left ventricles) is of great importance in pathogenesis of the development of acute heart failure in the early postoperative period in patients with mitral stenosis of the IIIrd and IVth stage of the blood circulation insufficiency.

Impaired chronotropic and vasodilator reserves limit exercise capacity in patients with heart failure and a preserved ejection fraction.

PubMed

Borlaug, Barry A; Melenovsky, Vojtech; Russell, Stuart D; Kessler, Kristy; Pacak, Karel; Becker, Lewis C; Kass, David A

2006-11-14

Nearly half of patients with heart failure have a preserved ejection fraction (HFpEF). Symptoms of exercise intolerance and dyspnea are most often attributed to diastolic dysfunction; however, impaired systolic and/or arterial vasodilator reserve under stress could also play an important role. Patients with HFpEF (n=17) and control subjects without heart failure (n=19) generally matched for age, gender, hypertension, diabetes mellitus, obesity, and the presence of left ventricular hypertrophy underwent maximal-effort upright cycle ergometry with radionuclide ventriculography to determine rest and exercise cardiovascular function. Resting cardiovascular function was similar between the 2 groups. Both had limited exercise capacity, but this was more profoundly reduced in HFpEF patients (exercise duration 180+/-71 versus 455+/-184 seconds; peak oxygen consumption 9.0+/-3.4 versus 14.4+/-3.4 mL x kg(-1) x min(-1); both P<0.001). At matched low-level workload, HFpEF subjects displayed approximately 40% less of an increase in heart rate and cardiac output and less systemic vasodilation (all P<0.05) despite a similar rise in end-diastolic volume, stroke volume, and contractility. Heart rate recovery after exercise was also significantly delayed in HFpEF patients. Exercise capacity correlated with the change in cardiac output, heart rate, and vascular resistance but not end-diastolic volume or stroke volume. Lung blood volume and plasma norepinephrine levels rose similarly with exercise in both groups. HFpEF patients have reduced chronotropic, vasodilator, and cardiac output reserve during exercise compared with matched subjects with hypertensive cardiac hypertrophy. These limitations cannot be ascribed to diastolic abnormalities per se and may provide novel therapeutic targets for interventions to improve exercise capacity in this disorder.

The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

PubMed

Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

2016-02-01

Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output. © 2016. Published by The Company of Biologists Ltd.

Improved cardiac filling facilitates the postprandial elevation of stroke volume in Python regius.

PubMed

Enok, Sanne; Leite, Gabriella S P C; Leite, Cléo A C; Gesser, Hans; Hedrick, Michael S; Wang, Tobias

2016-10-01

To accommodate the pronounced metabolic response to digestion, pythons increase heart rate and elevate stroke volume, where the latter has been ascribed to a massive and fast cardiac hypertrophy. However, numerous recent studies show that heart mass rarely increases, even upon ingestion of large meals, and we therefore explored the possibility that a rise in mean circulatory filling pressure (MCFP) serves to elevate venous pressure and cardiac filling during digestion. To this end, we measured blood flows and pressures in anaesthetized Python regius The anaesthetized snakes exhibited the archetypal tachycardia as well as a rise in both venous pressure and MCFP that fully account for the approximate doubling of stroke volume. There was no rise in blood volume and the elevated MCFP must therefore stem from increased vascular tone, possibly by means of increased sympathetic tone on the veins. Furthermore, although both venous pressure and MCFP increased during volume loading, there was no evidence that postprandial hearts were endowed with an additional capacity to elevate stroke volume. In vitro measurements of force development of paced ventricular strips also failed to reveal signs of increased contractility, but the postprandial hearts had higher activities of cytochrome oxidase and pyruvate kinase, which probably serves to sustain the rise in cardiac work during digestion. © 2016. Published by The Company of Biologists Ltd.

Right Ventricular Volumes and Systolic Function by Cardiac Magnetic Resonance and the Impact of Sex, Age, and Obesity in a Longitudinally Followed Cohort Free of Pulmonary and Cardiovascular Disease: The Framingham Heart Study.

PubMed

Foppa, Murilo; Arora, Garima; Gona, Philimon; Ashrafi, Arman; Salton, Carol J; Yeon, Susan B; Blease, Susan J; Levy, Daniel; O'Donnell, Christopher J; Manning, Warren J; Chuang, Michael L

2016-03-01

Cardiac magnetic resonance is uniquely well suited for noninvasive imaging of the right ventricle. We sought to define normal cardiac magnetic resonance reference values and to identify the main determinants of right ventricular (RV) volumes and systolic function using a modern imaging sequence in a community-dwelling, longitudinally followed cohort free of clinical cardiovascular and pulmonary disease. The Framingham Heart Study Offspring cohort has been followed since 1971. We scanned 1794 Offspring cohort members using steady-state free precession cardiac magnetic resonance and identified a reference group of 1336 adults (64±9 years, 576 men) free of prevalent cardiovascular and pulmonary disease. RV trabeculations and papillary muscles were considered cavity volume. Men had greater RV volumes and cardiac output before and after indexation to body size (all P<0.001). Women had higher RV ejection fraction than men (68±6% versus 64±7%; P<0.0001). RV volumes and cardiac output decreased with advancing age. There was an increase in raw and height-indexed RV measurements with increasing body mass index, but this trend was weakly inverted after indexation of RV volumes to body surface area. Sex, age, height, body mass index, and heart rate account for most of the variability in RV volumes and function in this community-dwelling population. We report sex-specific normative values for RV measurements among principally middle-aged and older adults. RV ejection fraction is greater in women. RV volumes increase with body size, are greater in men, and are smaller in older people. Body surface area seems to be appropriate for indexation of cardiac magnetic resonance-derived RV volumes. © 2016 American Heart Association, Inc.

Effects of passive heating on central blood volume and ventricular dimensions in humans

PubMed Central

Crandall, C G; Wilson, T E; Marving, J; Vogelsang, T W; Kjaer, A; Hesse, B; Secher, N H

2008-01-01

Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.e. non-heat stressed) subjects participated in this protocol. Changes in regional blood volume during heat stress and time control were estimated using technetium-99m labelled autologous red blood cells and gamma camera imaging. Whole-body heating increased internal temperature (≥ 1.0°C), cutaneous vascular conductance (approximately fivefold), and heart rate (52 ± 2 to 93 ± 4 beats min−1), while reducing central venous pressure (5.5 ± 07 to 0.2 ± 0.6 mmHg) accompanied by minor decreases in mean arterial pressure (all P < 0.05). The heat stress reduced the blood volume of the heart (18 ± 2%), heart plus central vasculature (17 ± 2%), thorax (14 ± 2%), inferior vena cava (23 ± 2%) and liver (23 ± 2%) (all P≤ 0.005 relative to time control subjects). Radionuclide multiple-gated acquisition assessment revealed that heat stress did not significantly change left ventricular end-diastolic volume, while ventricular end-systolic volume was reduced by 24 ± 6% of pre-heat stress levels (P < 0.001 relative to time control subjects). Thus, heat stress increased left ventricular ejection fraction from 60 ± 1% to 68 ± 2% (P= 0.02). We conclude that heat stress shifts blood volume from thoracic and splanchnic regions presumably to aid in heat dissipation, while simultaneously increasing heart rate and ejection fraction. PMID:17962331

Anterior Myocardial Territory May Replace the Heart as Organ at Risk in Intensity-Modulated Radiotherapy for Left-Sided Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan Wenyong; Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan; Liu Dong

Purpose: We investigated whether the heart could be replaced by the anterior myocardial territory (AMT) as the organ at risk (OAR) in intensity-modulated radiotherapy (IMRT) of the breast for patients with left-sided breast cancer. Methods and Materials: Twenty-three patients with left-sided breast cancer who received postoperative radiation after breast-conserving surgery were studied. For each patient, we generated five IMRT plans including heart (H), left ventricle (LV), AMT, LV+AMT, and H+LV as the primary OARs, respectively, except both lungs and right breast, which corresponded to IMRT(H), IMRT(LV), IMRT(AMT), IMRT(LV+AMT), and IMRT(H+LV). For the planning target volumes and OARs, the parameters ofmore » dose-volume histograms were compared. Results: The homogeneity index, conformity index, and coverage index were not compromised significantly in IMRT(AMT), IMRT(LV) and IMRT(LV+ AMT), respectively, when compared with IMRT(H). The mean dose to the heart, LV, and AMT decreased 5.3-21.5% (p < 0.05), 19.9-29.5% (p < 0.05), and 13.3-24.5% (p < 0.05), respectively. Similarly, the low (e.g., V5%), middle (e.g., V20%), and high (e.g., V30%) dose-volume of the heart, LV, and AMT decreased with different levels. The mean dose and V10% of the right lung increased by 9.2% (p < 0.05) and 27.6% (p < 0.05), respectively, in IMRT(LV), and the mean dose and V5% of the right breast decreased significantly in IMRT(AMT) and IMRT(LV+AMT). IMRT(AMT) was the preferred plan and was then compared with IMRT(H+LV); the majority of dose-volume histogram parameters of OARs including the heart, LV, AMT, both lungs, and the right breast were not statistically different. However, the low dose-volume of LV increased and the middle dose-volume decreased significantly (p < 0.05) in IMRT(AMT). Also, those of the right lung (V10%, V15%) and right breast (V5%, V10%) decreased significantly (p < 0.05). Conclusions: The AMT may replace the heart as the OAR in left-sided breast IMRT after breast-conserving surgery to decrease the radiation dose to the heart.« less

Pulmonary Hyperinflation and Left Ventricular Mass

PubMed Central

Smith, Benjamin M; Kawut, Steven M.; Bluemke, David A; Basner, Robert C; Gomes, Antoinette S; Hoffman, Eric; Kalhan, Ravi; Lima, João AC; Liu, Chia-Ying; Michos, Erin D; Prince, Martin R; Rabbani, LeRoy; Rabinowitz, Daniel; Shimbo, Daichi; Shea, Steven; Barr, R Graham

2013-01-01

Background Left ventricular (LV) mass is an important predictor of heart failure and cardiovascular mortality, yet determinants of LV mass are incompletely understood. Pulmonary hyperinflation in chronic obstructive pulmonary disease (COPD) may contribute to changes in intrathoracic pressure that increase LV wall stress. We therefore hypothesized that residual lung volume in COPD would be associated with greater LV mass. Methods and results The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited smokers aged 50–79 years who were free of clinical cardiovascular disease. LV mass was measured by cardiac magnetic resonance. Pulmonary function testing was performed according to guidelines. Regression models were used to adjust for age, sex, body size, blood pressure and other cardiac risk factors. Among 119 MESA COPD Study participants, mean age was 69±6 years, 55% were male and 65% had COPD, mostly of mild or moderate severity. Mean LV mass was 128±34 grams. Residual lung volume was independently associated with greater LV mass (7.2 grams per standard deviation increase in residual volume; 95% CI 2.2 to 12; P=0.004), and was similar in magnitude to that of systolic blood pressure (7.6 grams per standard deviation increase in systolic blood pressure, 95% CI 4.3 to 11 grams; p<0.001). Similar results were observed for LV mass to end-diastolic volume ratio (p=0.02) and with hyperinflation measured as residual volume to total lung capacity ratio (P=0.009). Conclusions Pulmonary hyperinflation, as measured by residual lung volume or residual lung volume to total lung capacity ratio, is associated with greater LV mass. PMID:23493320

Vortex ring behavior provides the epigenetic blueprint for the human heart

PubMed Central

Arvidsson, Per M.; Kovács, Sándor J.; Töger, Johannes; Borgquist, Rasmus; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

2016-01-01

The laws of fluid dynamics govern vortex ring formation and precede cardiac development by billions of years, suggesting that diastolic vortex ring formation is instrumental in defining the shape of the heart. Using novel and validated magnetic resonance imaging measurements, we show that the healthy left ventricle moves in tandem with the expanding vortex ring, indicating that cardiac form and function is epigenetically optimized to accommodate vortex ring formation for volume pumping. Healthy hearts demonstrate a strong coupling between vortex and cardiac volumes (R2 = 0.83), but this optimized phenotype is lost in heart failure, suggesting restoration of normal vortex ring dynamics as a new, and possibly important consideration for individualized heart failure treatment. Vortex ring volume was unrelated to early rapid filling (E-wave) velocity in patients and controls. Characteristics of vortex-wall interaction provide unique physiologic and mechanistic information about cardiac diastolic function that may be applied to guide the design and implantation of prosthetic valves, and have potential clinical utility as therapeutic targets for tailored medicine or measures of cardiac health. PMID:26915473

Vortex ring behavior provides the epigenetic blueprint for the human heart.

PubMed

Arvidsson, Per M; Kovács, Sándor J; Töger, Johannes; Borgquist, Rasmus; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

2016-02-26

The laws of fluid dynamics govern vortex ring formation and precede cardiac development by billions of years, suggesting that diastolic vortex ring formation is instrumental in defining the shape of the heart. Using novel and validated magnetic resonance imaging measurements, we show that the healthy left ventricle moves in tandem with the expanding vortex ring, indicating that cardiac form and function is epigenetically optimized to accommodate vortex ring formation for volume pumping. Healthy hearts demonstrate a strong coupling between vortex and cardiac volumes (R(2) = 0.83), but this optimized phenotype is lost in heart failure, suggesting restoration of normal vortex ring dynamics as a new, and possibly important consideration for individualized heart failure treatment. Vortex ring volume was unrelated to early rapid filling (E-wave) velocity in patients and controls. Characteristics of vortex-wall interaction provide unique physiologic and mechanistic information about cardiac diastolic function that may be applied to guide the design and implantation of prosthetic valves, and have potential clinical utility as therapeutic targets for tailored medicine or measures of cardiac health.

Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

PubMed Central

Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

2014-01-01

Background Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. Objective To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Methods Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. Results In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m2 were associated with a significant increase in mortality (log rank p < 0.0001). Conclusion The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction. PMID:24553982

Echocardiographic parameters and survival in Chagas heart disease with severe systolic dysfunction.

PubMed

Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Arruda, Ana Lúcia Martins; Hotta, Viviane Tiemi; Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador

2014-03-01

Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m2 were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.

Cone beam computed tomography-derived adaptive radiotherapy for radical treatment of esophageal cancer.

PubMed

Hawkins, Maria A; Brooks, Corrinne; Hansen, Vibeke N; Aitken, Alexandra; Tait, Diana M

2010-06-01

To investigate the potential for reduction in normal tissue irradiation by creating a patient specific planning target volume (PTV) using cone beam computed tomography (CBCT) imaging acquired in the first week of radiotherapy for patients receiving radical radiotherapy. Patients receiving radical RT for carcinoma of the esophagus were investigated. The PTV is defined as CTV(tumor, nodes) plus esophagus outlined 3 to 5 cm cranio-caudally and a 1.5-cm circumferential margin is added (clinical plan). Prefraction CBCT are acquired on Days 1 to 4, then weekly. No correction for setup error made. The images are imported into the planning system. The tumor and esophagus for the length of the PTV are contoured on each CBCT and 5 mm margin is added. A composite volume (PTV1) is created using Week 1 composite CBCT volumes. The same process is repeated using CBCT Week 2 to 6 (PTV2). A new plan is created using PTV1 (adaptive plan). The coverage of the 95% isodose of PTV1 is evaluated on PTV2. Dose-volume histograms (DVH) for lungs, heart, and cord for two plans are compared. A total of 139 CBCT for 14 cases were analyzed. For the adaptive plan the coverage of the 95% prescription isodose for PTV1 = 95.6% +/- 4% and the PTV2 = 96.8% +/- 4.1% (t test, 0.19). Lungs V20 (15.6 Gy vs. 10.2 Gy) and heart mean dose (26.9 Gy vs. 20.7 Gy) were significantly smaller for the adaptive plan. A reduced planning volume can be constructed within the first week of treatment using CBCT. A single plan modification can be performed within the second week of treatment with considerable reduction in organ at risk dose. Copyright 2010 Elsevier Inc. All rights reserved.

Acellular therapeutic approach for heart failure: in vitro production of extracellular vesicles from human cardiovascular progenitors.

PubMed

El Harane, Nadia; Kervadec, Anaïs; Bellamy, Valérie; Pidial, Laetitia; Neametalla, Hany J; Perier, Marie-Cécile; Lima Correa, Bruna; Thiébault, Léa; Cagnard, Nicolas; Duché, Angéline; Brunaud, Camille; Lemitre, Mathilde; Gauthier, Jeanne; Bourdillon, Alexandra T; Renault, Marc P; Hovhannisyan, Yeranuhi; Paiva, Solenne; Colas, Alexandre R; Agbulut, Onnik; Hagège, Albert; Silvestre, Jean-Sébastien; Menasché, Philippe; Renault, Nisa K E

2018-05-21

We have shown that extracellular vesicles (EVs) secreted by embryonic stem cell-derived cardiovascular progenitor cells (Pg) recapitulate the therapeutic effects of their parent cells in a mouse model of chronic heart failure (CHF). Our objectives are to investigate whether EV released by more readily available cell sources are therapeutic, whether their effectiveness is influenced by the differentiation state of the secreting cell, and through which mechanisms they act. The total EV secreted by human induced pluripotent stem cell-derived cardiovascular progenitors (iPSC-Pg) and human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) were isolated by ultracentrifugation and characterized by Nanoparticle Tracking Analysis, western blot, and cryo-electron microscopy. In vitro bioactivity assays were used to evaluate their cellular effects. Cell and EV microRNA (miRNA) content were assessed by miRNA array. Myocardial infarction was induced in 199 nude mice. Three weeks later, mice with left ventricular ejection fraction (LVEF) ≤ 45% received transcutaneous echo-guided injections of iPSC-CM (1.4 × 106, n = 19), iPSC-Pg (1.4 × 106, n = 17), total EV secreted by 1.4 × 106 iPSC-Pg (n = 19), or phosphate-buffered saline (control, n = 17) into the peri-infarct myocardium. Seven weeks later, hearts were evaluated by echocardiography, histology, and gene expression profiling, blinded to treatment group. In vitro, EV were internalized by target cells, increased cell survival, cell proliferation, and endothelial cell migration in a dose-dependent manner and stimulated tube formation. Extracellular vesicles were rich in miRNAs and most of the 16 highly abundant, evolutionarily conserved miRNAs are associated with tissue-repair pathways. In vivo, EV outperformed cell injections, significantly improving cardiac function through decreased left ventricular volumes (left ventricular end systolic volume: -11%, P < 0.001; left ventricular end diastolic volume: -4%, P = 0.002), and increased LVEF (+14%, P < 0.0001) relative to baseline values. Gene profiling revealed that EV-treated hearts were enriched for tissue reparative pathways. Extracellular vesicles secreted by iPSC-Pg are effective in the treatment of CHF, possibly, in part, through their specific miRNA signature and the associated stimulation of distinct cardioprotective pathways. The processing and regulatory advantages of EV could make them effective substitutes for cell transplantation.

Resource Utilization for Initial Hospitalization in Pediatric Heart Transplantation in the United States.

PubMed

Boucek, Dana M; Lal, Ashwin K; Eckhauser, Aaron W; Weng, Hsin-Yi Cindy; Sheng, Xiaoming; Wilkes, Jacob F; Pinto, Nelangi M; Menon, Shaji C

2018-04-15

Pediatric heart transplantation (HT) is resource intensive. Event-driven pediatric databases do not capture data on resource use. The objective of this study was to evaluate resource utilization and identify associated factors during initial hospitalization for pediatric HT. This multicenter retrospective cohort study utilized the Pediatric Health Information Systems database (43 children's hospitals in the United States) of children ≤19 years of age who underwent transplant between January 2007 and July 2013. Demographic variables including site, payer, distance and time to center, clinical pre- and post-transplant variables, mortality, cost, and charge were the data collected. Total length of stay (LOS) and charge for the initial hospitalization were used as surrogates for resource use. Charges were inflation adjusted to 2013 dollars. Of 1,629 subjects, 54% were male, and the median age at HT was 5 years (IQR [interquartile range] 0 to 13). The median total and intensive care unit LOS were 51 (IQR 23 to 98) and 23 (IQR 9 to 58) days, respectively. Total charge and cost for hospitalization were $852,713 ($464,900 to $1,609,300) and $383,600 ($214,900 to $681,000) respectively. Younger age, lower volume center, southern region, and co-morbidities before transplant were associated with higher resource use. In later years, charges increased despite shorter LOS. In conclusion, this large multicenter study provides novel insight into factors associated with resource use in pediatric patients having HT. Peritransplant morbidities are associated with increased cost and LOS. Reducing costs in line with LOS will improve health-care value. Regional and center volume differences need further investigation for optimizing value-based care and efficient use of scarce resources. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of a 12-week intervention period with football and running for habitually active men with mild hypertension.

PubMed

Knoepfli-Lenzin, C; Sennhauser, C; Toigo, M; Boutellier, U; Bangsbo, J; Krustrup, P; Junge, A; Dvorak, J

2010-04-01

The present study examined the effect of football (F, n=15) training on the health profile of habitually active 25-45-year-old men with mild hypertension and compared it with running (R, n=15) training and no additional activity (controls, C, n=17). The participants in F and R completed a 1-h training session 2.4 times/week for 12 weeks. Systolic and diastolic blood pressure decreased in all groups but the decrease in diastolic blood pressure in F (-9 +/- 5 (+/- SD) mmHg) was higher than that in C (-4 +/- 6 mmHg). F was as effective as R in decreasing body mass (-1.6 +/- 1.8 vs-1.5 +/- 2.1 kg) and total fat mass (-2.0 +/- 1.5 vs -1.6 +/- 1.5 kg) and in increasing supine heart rate variability, whereas no changes were detected for C. Maximal stroke volume improved in F (+13.1%) as well as in R (+10.1%) compared with C (-4.9%). Total cholesterol decreased in F (5.8 +/- 1.2 to 5.5 +/- 0.9 mmol/L) but was not altered in R and C. We conclude that football training, consisting of high-intensity intermittent exercise, results in positive effects on blood pressure, body composition, stroke volume and supine heart rate variability, and elicits at least the same cardiovascular health benefits as continuous running exercise in habitually active men with mild hypertension.

Cardiovascular effects of fenoterol under conditions of hypoxaemia.

PubMed Central

Bremner, P; Burgess, C D; Crane, J; McHaffie, D; Galletly, D; Pearce, N; Woodman, K; Beasley, R

1992-01-01

BACKGROUND: The reason for the association of increased risk of death with fenoterol in patients with asthma in New Zealand is unknown but may relate to its cardiovascular effects. Most deaths from asthma occur outside hospital, where hypoxaemia is likely to be a complicating factor. The cardiovascular effects of fenoterol have been investigated therefore under conditions of normoxaemia and hypoxaemia. METHOD: Eight healthy men were studied on two occasions. Measurements of heart rate, blood pressure, total electromechanical systole (QS2I), electrocardiographic QTc interval, cardiac index, stroke volume, and ejection fraction were made under conditions of normoxaemia and hypoxaemia (arterial oxygen saturation 90%) before and after administration of 800 micrograms of fenoterol by a metered dose inhaler. The order in which treatments were applied was according to a Latin square design. RESULTS: Before inhalation of fenoterol hypoxaemia was associated with a significant increase in heart rate (8 beats/min) and QTc interval (15.6 ms). Under conditions of normoxaemia fenoterol caused a significant increase in heart rate (14.3 beats/min), systolic blood pressure (7.7 mm Hg), stroke volume (27.7 ml), cardiac index (1.6 1/min/m2), ejection fraction (11.48), and QTc interval (32.9 ms) and a fall in QS2I (-23.2 ms) and diastolic blood pressure (-8.4 mm Hg). Under conditions of hypoxaemia the changes after inhalation of fenoterol were similar to those recorded during normoxaemia; thus the effects of hypoxaemia and fenoterol were additive (heart rate 21.9 beats/min, QTc 43.5 ms with fenoterol and hypoxaemia). CONCLUSION: The chronotropic and electrophysiological effects of fenoterol were enhanced by conditions of hypoxaemia. PMID:1481183

Mid-Term Results of Surgical Treatment of Atrial Fibrillation in Valvular Heart Disease Assesed by Speckle Tracking Echocardiography

PubMed Central

Lorenzo, Natalia; Mendez, Irene; Taibo, Mikel; Martinis, Gianfranco; Badia, Sara; Reyes, Guillermo; Aguilar, Rio

2018-01-01

Background Atrial fibrillation frequently affects patients with valvular heart disease. Ablation of atrial fibrillation during valvular surgery is an alternative for restoring sinus rhythm. Objectives This study aimed to evaluate mid-term results of successful atrial fibrillation surgical ablation during valvular heart disease surgery, to explore left atrium post-ablation mechanics and to identify predictors of recurrence. Methods Fifty-three consecutive candidates were included. Eligibility criteria for ablation included persistent atrial fibrillation <10 years and left atrium diameter < 6.0 cm. Three months after surgery, echocardiogram, 24-hour Holter monitoring and electrocardiograms were performed in all candidates who maintained sinus rhythm (44 patients). Echo-study included left atrial deformation parameters (strain and strain rate), using 2-dimensional speckle-tracking echocardiography. Simultaneously, 30 healthy individuals (controls) were analyzed with the same protocol for left atrial performance. Significance was considered with a P value of < 0.05. Results After a mean follow up of 17 ± 2 months, 13 new post-operative cases of recurrent atrial fibrillation were identified. A total of 1,245 left atrial segments were analysed. Left atrium was severely dilated in the post-surgery group and, mechanical properties of left atrium did not recover after surgery when compared with normal values. Left atrial volume (≥ 64 mL/m2) was the only independent predictor of atrial fibrillation recurrence (p = 0.03). Conclusions Left atrial volume was larger in patients with atrial fibrillation recurrence and emerges as the main predictor of recurrences, thereby improving the selection of candidates for this therapy; however, no differences were found regarding myocardial deformation parameters. Despite electrical maintenance of sinus rhythm, left atrium mechanics did not recover after atrial fibrillation ablation performed during valvular heart disease surgery. PMID:29561964

The Aachen miniaturized heart-lung machine--first results in a small animal model.

PubMed

Schnoering, Heike; Arens, Jutta; Sachweh, Joerg S; Veerman, Melanie; Tolba, Rene; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Vazquez-Jimenez, Jaime F

2009-11-01

Congenital heart surgery most often incorporates extracorporeal circulation. Due to foreign surface contact and the administration of foreign blood in many children, inflammatory response and hemolysis are important matters of debate. This is particularly an issue in premature and low birth-weight newborns. Taking these considerations into account, the Aachen miniaturized heart-lung machine (MiniHLM) with a total static priming volume of 102 mL (including tubing) was developed and tested in a small animal model. Fourteen female Chinchilla Bastard rabbits were operated on using two different kinds of circuits. In eight animals, a conventional HLM with Dideco Kids oxygenator and Stöckert roller pump (Sorin group, Milan, Italy) was used, and the Aachen MiniHLM was employed in six animals. Outcome parameters were hemolysis and blood gas analysis including lactate. The rabbits were anesthetized, and a standard median sternotomy was performed. The ascending aorta and the right atrium were cannulated. After initiating cardiopulmonary bypass, the aorta was cross-clamped, and cardiac arrest was induced by blood cardioplegia. Blood samples for hemolysis and blood gas analysis were drawn before, during, and after cardiopulmonary bypass. After 1 h aortic clamp time, all animals were weaned from cardiopulmonary bypass. Blood gas analysis revealed adequate oxygenation and perfusion during cardiopulmonary bypass, irrespective of the employed perfusion system. The use of the Aachen MiniHLM resulted in a statistically significant reduced decrease in fibrinogen during cardiopulmonary bypass. A trend revealing a reduced increase in free hemoglobin during bypass in the MiniHLM group could also be observed. This newly developed Aachen MiniHLM with low priming volume, reduced hemolysis, and excellent gas transfer (O(2) and CO(2)) may reduce circuit-induced complications during heart surgery in neonates.

Sugary beverage intake and preclinical Alzheimer's disease in the community.

PubMed

Pase, Matthew P; Himali, Jayandra J; Jacques, Paul F; DeCarli, Charles; Satizabal, Claudia L; Aparicio, Hugo; Vasan, Ramachandran S; Beiser, Alexa S; Seshadri, Sudha

2017-09-01

Excess sugar consumption has been linked with Alzheimer's disease (AD) pathology in animal models. We examined the cross-sectional association of sugary beverage consumption with neuropsychological (N = 4276) and magnetic resonance imaging (N = 3846) markers of preclinical Alzheimer's disease and vascular brain injury (VBI) in the community-based Framingham Heart Study. Intake of sugary beverages was estimated using a food frequency questionnaire. Relative to consuming less than one sugary beverage per day, higher intake of sugary beverages was associated with lower total brain volume (1-2/day, β ± standard error [SE] = -0.55 ± 0.14 mean percent difference, P = .0002; >2/day, β ± SE = -0.68 ± 0.18, P < .0001), and poorer performance on tests of episodic memory (all P < .01). Daily fruit juice intake was associated with lower total brain volume, hippocampal volume, and poorer episodic memory (all P < .05). Sugary beverage intake was not associated with VBI in a consistent manner across outcomes. Higher intake of sugary beverages was associated cross-sectionally with markers of preclinical AD. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Late Cardiac Toxicity After Mediastinal Radiation Therapy for Hodgkin Lymphoma: Contributions of Coronary Artery and Whole Heart Dose-Volume Variables to Risk Prediction.

PubMed

Hahn, Ezra; Jiang, Haiyan; Ng, Angela; Bashir, Shaheena; Ahmed, Sameera; Tsang, Richard; Sun, Alexander; Gospodarowicz, Mary; Hodgson, David

2017-08-01

Mediastinal radiation therapy (RT) for Hodgkin lymphoma (HL) is associated with late cardiotoxicity, but there are limited data to indicate which dosimetric parameters are most valuable for predicting this risk. This study investigated which whole heart dosimetric measurements provide the most information regarding late cardiotoxicity, and whether coronary artery dosimetry was more predictive of this outcome than whole heart dosimetry. A random sample of 125 HL patients treated with mediastinal RT was selected, and 3-dimensional cardiac dose-volume data were generated from historical plans using validated methods. Cardiac events were determined by linking patients to population-based datasets of inpatient and same-day hospitalizations and same-day procedures. Variables collected for the whole heart and 3 coronary arteries included the following: Dmean, Dmax, Dmin, dose homogeneity, V5, V10, V20, and V30. Multivariable competing risk regression models were generated for the whole heart and coronary arteries. There were 44 cardiac events documented, of which 70% were ischemic. The best multivariable model included the following covariates: whole heart Dmean (hazard ratio [HR] 1.09, P=.0083), dose homogeneity (HR 0.94, P=.0034), male sex (HR 2.31, P=.014), and age (HR 1.03, P=.0049). When any adverse cardiac event was the outcome, models using coronary artery variables did not perform better than models using whole heart variables. However, in a subanalysis of ischemic cardiac events only, the model using coronary artery variables was superior to the whole heart model and included the following covariates: age (HR 1.05, P<.001), volume of left anterior descending artery receiving 5 Gy (HR 0.98, P=.003), and volume of left circumflex artery receiving 20 Gy (HR 1.03, P<.001). In addition to higher mean heart dose, increasing inhomogeneity in cardiac dose was associated with a greater risk of late cardiac effects. When all types of cardiotoxicity were evaluated, the whole heart variable model outperformed the coronary artery models. However, when events were limited to ischemic cardiotoxicity, the coronary artery-based model was superior. Copyright © 2017 Elsevier Inc. All rights reserved.

Cardiovascular simulator improvement: pressure versus volume loop assessment.

PubMed

Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Leme, Juliana; Legendre, Daniel; Bock, Eduardo; Lucchi, Julio Cesar

2011-05-01

This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance. In many heart diseases, the stroke volume decreases because of low heart contractility. This pathological situation must be simulated by the PCS in order to evaluate the assistance provided by a ventricular assist device (VAD). The PCS system is automatically controlled by a computer and is an auxiliary tool for VAD control strategies development. This PCS system is according to a Windkessel model where lumped parameters are used for cardiovascular system analysis. Peripheral resistance, arteries compliance, and fluid inertance are simulated. The simulator has an actuator with a roller screw and brushless direct current motor, and the stroke volume is regulated by the actuator displacement. Internal pressure and volume measurements are monitored to obtain the PxV loop. Left chamber internal pressure is directly obtained by pressure transducer; however, internal volume has been obtained indirectly by using a linear variable differential transformer, which senses the diaphragm displacement. Correlations between the internal volume and diaphragm position are made. LabVIEW integrates these signals and shows the pressure versus internal volume loop. The results that have been obtained from the PCS system show PxV loops at different ventricle elastances, making possible the simulation of pathological situations. A preliminary test with a pulsatile VAD attached to PCS system was made. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to <10 Gy Total Body Irradiation.

PubMed

Unthank, Joseph L; Miller, Steven J; Quickery, Ariel K; Ferguson, Ethan L; Wang, Meijing; Sampson, Carol H; Chua, Hui Lin; DiStasi, Matthew R; Feng, Hailin; Fisher, Alexa; Katz, Barry P; Plett, P Artur; Sandusky, George E; Sellamuthu, Rajendran; Vemula, Sasidhar; Cohen, Eric P; MacVittie, Thomas J; Orschell, Christie M

2015-11-01

The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p < 0.01 vs. non-irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p < 0.01 vs. non-irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs.

Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates.

PubMed

Carmody, J Bryan; Seckeler, Michael D; Ballengee, Cortney R; Conaway, Mark; Jayakumar, K Anitha; Charlton, Jennifer R

2014-10-01

Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury. We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system. Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17). Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

Noninvasive Assessment of Preload Reserve Enhances Risk Stratification of Patients With Heart Failure With Reduced Ejection Fraction.

PubMed

Matsumoto, Kensuke; Onishi, Akira; Yamada, Hirotsugu; Kusunose, Kenya; Suto, Makiko; Hatani, Yutaka; Matsuzoe, Hiroki; Tatsumi, Kazuhiro; Tanaka, Hidekazu; Hirata, Ken-Ichi

2018-05-01

The leg-positive pressure maneuver can safely and noninvasively apply preload stress without increase in total body fluid volume. The purpose of this study was to determine whether preload stress could be useful for risk stratification of patients with heart failure with reduced ejection fraction. For this study, 120 consecutive patients with heart failure with reduced ejection fraction were prospectively recruited. The stroke work index was estimated as product of stroke volume index and mean blood pressure, and the E/e' ratio was calculated to estimate ventricular filling pressure. The echocardiographic parameters were obtained both at rest and during leg-positive pressure stress. During the median follow-up period of 20 months, 30 patients developed adverse cardiovascular events. During preload stress, stroke work index increased significantly (from 3280±1371 to 3857±1581 mm Hg·mL/m 2 ; P <0.001) along with minimal changes in ventricular filling pressure (E/e', from 16±10 to 17±9; P <0.05) in patients without cardiovascular events. However, patients with cardiovascular events showed impairment of Frank-Starling mechanism (stroke work index, from 2863±969 to 2903±1084 mm Hg·mL/m 2 ; P =0.70) and a serious increase in E/e' ratio (from 19±11 to 25±14; P <0.001). Both the patients without contractile reserve and those without diastolic reserve exhibited worse event-free survival than the others ( P <0.001). In a Cox proportional-hazards analysis, the changes in stroke work index (hazard ratio: 0.44 per 500 mm Hg·mL/m 2 increase; P =0.001) and in E/e' (hazard ratio: 2.58 per 5-U increase; P <0.001) were predictors of cardiovascular events. Contractile reserve and diastolic reserve during leg-positive pressure stress are important determinants of cardiovascular outcomes for patients with heart failure with reduced ejection fraction. © 2018 American Heart Association, Inc.

Combining MRI With PET for Partial Volume Correction Improves Image-Derived Input Functions in Mice

NASA Astrophysics Data System (ADS)

Evans, Eleanor; Buonincontri, Guido; Izquierdo, David; Methner, Carmen; Hawkes, Rob C.; Ansorge, Richard E.; Krieg, Thomas; Carpenter, T. Adrian; Sawiak, Stephen J.

2015-06-01

Accurate kinetic modelling using dynamic PET requires knowledge of the tracer concentration in plasma, known as the arterial input function (AIF). AIFs are usually determined by invasive blood sampling, but this is prohibitive in murine studies due to low total blood volumes. As a result of the low spatial resolution of PET, image-derived input functions (IDIFs) must be extracted from left ventricular blood pool (LVBP) ROIs of the mouse heart. This is challenging because of partial volume and spillover effects between the LVBP and myocardium, contaminating IDIFs with tissue signal. We have applied the geometric transfer matrix (GTM) method of partial volume correction (PVC) to 12 mice injected with 18F - FDG affected by a Myocardial Infarction (MI), of which 6 were treated with a drug which reduced infarction size [1]. We utilised high resolution MRI to assist in segmenting mouse hearts into 5 classes: LVBP, infarcted myocardium, healthy myocardium, lungs/body and background. The signal contribution from these 5 classes was convolved with the point spread function (PSF) of the Cambridge split magnet PET scanner and a non-linear fit was performed on the 5 measured signal components. The corrected IDIF was taken as the fitted LVBP component. It was found that the GTM PVC method could recover an IDIF with less contamination from spillover than an IDIF extracted from PET data alone. More realistic values of Ki were achieved using GTM IDIFs, which were shown to be significantly different (p <; 0.05) between the treated and untreated groups.

[Cardiovascular effects of prostaglandin F 2 alpha in early pregnancy].

PubMed

Retzke, U; Schwarz, R

1976-01-01

In 10 normotensive healthy early pregnant women cardiovascular studies were done before, during and after the intravenous administration of prostaglandin F2alpha with the method of quantitative sphygmometry. Arterial blood pressure was measured graphically with an automatic sphygmomanometer unit. Velocity of aortic pulse wave was determined directly on the principle of exact electronic timing. Prostaglandin F2alpha was infused with electric pump in the dosage of 6, 5, 13 and 26 mug per minute for 30 minutes in each case. Arterial blood pressure is nearly constant. Heart rate, the elasticity coefficient of the arteries E' and total peripheral resistance decreases significantly. Stroke volume, cardiac output, work and power of the heart increases significantly. Nevertheless there are no contra-indications on the part of cardiovascular system for using prostaglandin F2alpha for induction of abortion

Dosimetric aspects of breast radiotherapy with three-dimensional and intensity-modulated radiotherapy helical tomotherapy planning modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Poonam; Service of Radiation Therapy, University of Wisconsin Aspirus Cancer Center, Wisconsin Rapids, WI; Yan, Yue, E-mail: yyan5@mdanderson.org

In this work, we investigated the dosimetric differences between the intensity-modulated radiotherapy (IMRT) plans and the three-dimensional (3D) helical plans based on the TomoTherapy system. A total of 15 patients with supine setup were randomly selected from the data base. For patients with lumpectomy planning target volume (PTV), regional lymph nodes were also included as part of the target. For dose sparing, the significant differences between the helical IMRT and helical 3D were only found in the heart and contralateral breast. For the dose to the heart, helical IMRT reduced the maximum point dose by 6.98 Gy compared to themore » helical 3D plan (p = 0.01). For contralateral breast, the helical IMRT plans significantly reduced the maximum point dose by 5.6 Gy compared to the helical 3D plan. However, compared to the helical 3D plan, the helical IMRT plan increased the volume for lower dose (13.08% increase in V{sub 5} {sub Gy}, p = 0.01). In general, there are no significant differences in dose sparing between helical IMRT and helical 3D plans.« less

Temporal dynamics of the circadian heart rate following low and high volume exercise training in sedentary male subjects.

PubMed

Jelinek, Herbert F; Karmakar, C; Kiviniemi, A M; Hautala, A J; Tulppo, M P; Mäkikallio, T H; Huikuri, H V; Khandoker, A H; Palaniswami, M

2015-10-01

Increased risk of arrhythmic events occurs at certain times during the circadian cycle with the highest risk being in the second and fourth quarter of the day. Exercise improves treatment outcome in individuals with cardiovascular disease. How different exercise protocols affect the circadian rhythm and the associated decrease in adverse cardiovascular risk over the circadian cycle has not been shown. Fifty sedentary male participants were randomized into an 8-week high volume and moderate volume training and a control group. Heart rate was recorded using Polar Electronics and investigated with Cosinor analysis and by Poincaré plot derived features of SD1, SD2 and the complex correlation measure (CCM) at 1-h intervals over the 24-h period. Moderate exercise significantly increased vagal modulation and the temporal dynamics of the heart rate in the second quarter of the circadian cycle (p = 0.004 and p = 0.007 respectively). High volume exercise had a similar effect on vagal output (p = 0.003) and temporal dynamics (p = 0.003). Cosinor analysis confirms that the circadian heart rate displays a shift in the acrophage following moderate and high volume exercise from before waking (1st quarter) to after waking (2nd quarter of day). Our results suggest that exercise shifts vagal influence and increases temporal dynamics of the heart rate to the 2nd quarter of the day and suggest that this may be the underlying physiological change leading to a decrease in adverse arrhythmic events during this otherwise high-risk period.

Unique strain history during ejection in canine left ventricle.

PubMed

Douglas, A S; Rodriguez, E K; O'Dell, W; Hunter, W C

1991-05-01

Understanding the relationship between structure and function in the heart requires a knowledge of the connection between the local behavior of the myocardium (e.g., shortening) and the pumping action of the left ventricle. We asked the question, how do changes in preload and afterload affect the relationship between local myocardial deformation and ventricular volume? To study this, a set of small radiopaque beads was implanted in approximately 1 cm3 of the isolated canine heart left ventricular free wall. Using biplane cineradiography, we tracked the motion of these markers through various cardiac cycles (controlling pre- and afterload) using the relative motion of six markers to quantify the local three dimensional Lagrangian strain. Two different reference states (used to define the strains) were considered. First, we used the configuration of the heart at end diastole for that particular cardiac cycle to define the individual strains (which gave the local "shortening fraction") and the ejection fraction. Second, we used a single reference state for all cardiac cycles i.e., the end-diastolic state at maximum volume, to define absolute strains (which gave local fractional length) and the volume fraction. The individual strain versus ejection fraction trajectories were dependent on preload and afterload. For any one heart, however, each component of absolute strain was more tightly correlated to volume fraction. Around each linear regression, the individual measurements of absolute strain scattered with standard errors that averaged less than 7% of their range. Thus the canine hearts examined had a preferred kinematic (shape) history during ejection, different from the kinematics of filling and independent or pre-or afterload and of stroke volume.

Prognostic Factors in Severe Chagasic Heart Failure

PubMed Central

Costa, Sandra de Araújo; Rassi, Salvador; Freitas, Elis Marra da Madeira; Gutierrez, Natália da Silva; Boaventura, Fabiana Miranda; Sampaio, Larissa Pereira da Costa; Silva, João Bastista Masson

2017-01-01

Background Prognostic factors are extensively studied in heart failure; however, their role in severe Chagasic heart failure have not been established. Objectives To identify the association of clinical and laboratory factors with the prognosis of severe Chagasic heart failure, as well as the association of these factors with mortality and survival in a 7.5-year follow-up. Methods 60 patients with severe Chagasic heart failure were evaluated regarding the following variables: age, blood pressure, ejection fraction, serum sodium, creatinine, 6-minute walk test, non-sustained ventricular tachycardia, QRS width, indexed left atrial volume, and functional class. Results 53 (88.3%) patients died during follow-up, and 7 (11.7%) remained alive. Cumulative overall survival probability was approximately 11%. Non-sustained ventricular tachycardia (HR = 2.11; 95% CI: 1.04 - 4.31; p<0.05) and indexed left atrial volume ≥ 72 mL/m2 (HR = 3.51; 95% CI: 1.63 - 7.52; p<0.05) were the only variables that remained as independent predictors of mortality. Conclusions The presence of non-sustained ventricular tachycardia on Holter and indexed left atrial volume > 72 mL/m2 are independent predictors of mortality in severe Chagasic heart failure, with cumulative survival probability of only 11% in 7.5 years. PMID:28443956

Cardiac Magnetic Resonance-Measured Left Atrial Volume and Function and Incident Atrial Fibrillation: Results From MESA (Multi-Ethnic Study of Atherosclerosis).

PubMed

Habibi, Mohammadali; Samiei, Sanaz; Ambale Venkatesh, Bharath; Opdahl, Anders; Helle-Valle, Thomas M; Zareian, Mytra; Almeida, Andre L C; Choi, Eui-Young; Wu, Colin; Alonso, Alvaro; Heckbert, Susan R; Bluemke, David A; Lima, João A C

2016-08-01

Early detection of structural changes in left atrium (LA) before atrial fibrillation (AF) development could be helpful in identification of those at higher risk for AF. Using cardiac magnetic resonance imaging, we examined the association of LA volume and function, and incident AF in a multiethnic population free of clinical cardiovascular diseases. In a case-cohort study embedded in MESA (Multi-Ethnic Study of Atherosclerosis), baseline LA size and function assessed by cardiac magnetic resonance feature-tracking were compared between 197 participants with incident AF and 322 participants randomly selected from the whole MESA cohort. Participants were followed up for 8 years. Incident AF cases had a larger LA volume and decreased passive, active, and total LA emptying fractions and peak global LA longitudinal strain (peak LA strain) at baseline. In multivariable analysis, elevated LA maximum volume index (hazard ratio, 1.38 per SD; 95% confidence interval, 1.01-1.89) and decreased peak LA strain (hazard ratio, 0.68 per SD; 95% confidence interval, 0.48-0.96), and passive and total LA emptying fractions (hazard ratio for passive LA emptying fractions, 0.55 per SD; 95% confidence interval, 0.40-0.75 and hazard ratio for active LA emptying fractions, 0.70 per SD; 95% confidence interval, 0.52-0.95), but not active LA emptying fraction, were associated with incident AF. Elevated LA volumes and decreased passive and total LA emptying fractions were independently associated with incident AF in an asymptomatic multiethnic population. Including LA functional variables along with other risk factors of AF may help to better risk stratify individuals at risk of AF development. © 2016 American Heart Association, Inc.

Intravenously Delivered Mesenchymal Stem Cells: Systemic Anti-Inflammatory Effects Improve Left Ventricular Dysfunction in Acute Myocardial Infarction and Ischemic Cardiomyopathy.

PubMed

Luger, Dror; Lipinski, Michael J; Westman, Peter C; Glover, David K; Dimastromatteo, Julien; Frias, Juan C; Albelda, M Teresa; Sikora, Sergey; Kharazi, Alex; Vertelov, Grigory; Waksman, Ron; Epstein, Stephen E

2017-05-12

Virtually all mesenchymal stem cell (MSC) studies assume that therapeutic effects accrue from local myocardial effects of engrafted MSCs. Because few intravenously administered MSCs engraft in the myocardium, studies have mainly utilized direct myocardial delivery. We adopted a different paradigm. To test whether intravenously administered MSCs reduce left ventricular (LV) dysfunction both post-acute myocardial infarction and in ischemic cardiomyopathy and that these effects are caused, at least partly, by systemic anti-inflammatory activities. Mice underwent 45 minutes of left anterior descending artery occlusion. Human MSCs, grown chronically at 5% O 2 , were administered intravenously. LV function was assessed by serial echocardiography, 2,3,5-triphenyltetrazolium chloride staining determined infarct size, and fluorescence-activated cell sorting assessed cell composition. Fluorescent and radiolabeled MSCs (1×10 6 ) were injected 24 hours post-myocardial infarction and homed to regions of myocardial injury; however, the myocardium contained only a small proportion of total MSCs. Mice received 2×10 6 MSCs or saline intravenously 24 hours post-myocardial infarction (n=16 per group). At day 21, we harvested blood and spleens for fluorescence-activated cell sorting and hearts for 2,3,5-triphenyltetrazolium chloride staining. Adverse LV remodeling and deteriorating LV ejection fraction occurred in control mice with large infarcts (≥25% LV). Intravenous MSCs eliminated the progressive deterioration in LV end-diastolic volume and LV end-systolic volume. MSCs significantly decreased natural killer cells in the heart and spleen and neutrophils in the heart. Specific natural killer cell depletion 24 hours pre-acute myocardial infarction significantly improved infarct size, LV ejection fraction, and adverse LV remodeling, changes associated with decreased neutrophils in the heart. In an ischemic cardiomyopathy model, mice 4 weeks post-myocardial infarction were randomized to tail-vein injection of 2×10 6 MSCs, with injection repeated at week 3 (n=16) versus PBS control (n=16). MSCs significantly increased LV ejection fraction and decreased LV end-systolic volume. Intravenously administered MSCs for acute myocardial infarction attenuate the progressive deterioration in LV function and adverse remodeling in mice with large infarcts, and in ischemic cardiomyopathy, they improve LV function, effects apparently modulated in part by systemic anti-inflammatory activities. © 2017 American Heart Association, Inc.

Left ventricular function during lower body negative pressure

NASA Technical Reports Server (NTRS)

Ahmad, M.; Blomqvist, C. G.; Mullins, C. B.; Willerson, J. T.

1977-01-01

The response of the human left ventricle to lower body negative pressure (LBNP) and the relation between left ventricular function and hemodynamic response were investigated. Ventricular function curves relating stroke volume to end-diastolic volume were obtained in 12 normal men. Volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during lower body negative pressure (LBNP) at minus 40 mm Hg. End-diastolic volume decreased by 19% and stroke volume by 22%. There were no significant changes in heart rate, arterial blood pressure, or end-systolic volume. Thus, moderate levels of LBNP significantly reduce preload and stroke volume without affecting contractile state. The absence of significant changes in heart rate and arterial blood pressure in the presence of a significant reduction in stroke volume is consistent with an increase in systemic peripheral resistance mediated by low-pressure baroreceptors.

Cardiorespiratory interactions during periodic breathing in awake chronic heart failure patients.

PubMed

Pinna, G D; Maestri, R; Mortara, A; La Rovere, M T

2000-03-01

We applied spectral techniques to the analysis of cardiorespiratory signals [instantaneous lung volume (ILV), instantaneous tidal volume (ITV), arterial O(2) saturation (Sa(O(2))) at the ear, heart rate (HR), systolic (SAP), and diastolic (DAP) arterial pressure] during nonapneic periodic breathing (PB) in 29 awake chronic heart failure (CHF) patients and estimated the timing relationships between respiratory and slow cardiovascular (<0.04 Hz) oscillations. Our aim was 1) to elucidate major mechanisms involved in cardiorespiratory interactions during PB and 2) to test the hypothesis of a central vasomotor origin of PB. All cardiovascular signals were characterized by a dominant (>/=84% of total power) oscillation at the frequency of PB (mean +/- SE: 0.022 +/- 0.0008 Hz), highly coherent (>/=0.89), and delayed with respect to ITV (ITV-HR, 2.4 +/- 0.72 s; ITV-SAP, 6.7 +/- 0.65 s; ITV-DAP, 3.2 +/- 0.61 s; P < 0.01). Sa(O(2)) was highly coherent with (coherence function = 0.96 +/- 0. 009) and almost opposite in phase to ITV. These findings demonstrate the existence of a generalized cardiorespiratory rhythm led by the ventilatory oscillation and suggest that 1) the cyclic increase in inspiratory drive and cardiopulmonary reflexes and 2) mechanical effects of PB-induced changes in intrathoracic pressure are the more likely sources of the HR and blood pressure oscillations, respectively. The timing relationship between ITV and blood pressure signals excludes the possibility that PB represents the effect of a central vasomotor rhythm.

Heart Rots of Red and White Firs

Treesearch

J.W. Kimmey; H.H. Jr. Bynum

1961-01-01

Heart rots, caused by fungi that attack the heartwood of living trees, are responsible for the greatest volume loss sustained by California red fir (Abies magnifica A. Murr.) and white fir (A. concolor (Gord. and Glend.) Lindl.). These two firs comprise 25 percent of the commercial timber of California. More than 13 percent of the volume in these firs is useless cull...

Cardiorespiratory responses to orthostasis and the effects of propranolol

NASA Technical Reports Server (NTRS)

Loeppky, J. A.

1975-01-01

Cardiac output and gas exchange were determined serially using the single-breath method of Kim et al. before, during, and after orthostasis on six subjects after beta-adrenergic blockage and in duplicate controls. In the latter, heart rate increased and pulse pressure dropped immediately on tilting to 60 deg and remained stable while cardiac output and stroke volume declined gradually over 21 min upright. On propranolol, heart rate was 10 bpm lower supine and 20 bpm less at 60 deg but cardiac output was only slightly lower before and following tilt-up. However, after 15 min upright, stroke volume and cardiac output recovered on propranolol exceeding the controls after 21 min without change in heart rate. Returning to supine, heart rate dropped in all tests with a transitory increase in stroke volume, cardiac output and arteriovenous O2 difference. At the same time, apparent O2 uptake increased temporarily, reflecting the return of pooled venous blood to the lungs. Orthostatic tolerance did not appear to be affected by beta-adrenergic blockade.

Vicious circle between progressive right ventricular dilatation and pulmonary regurgitation in patients after tetralogy of Fallot repair? Right heart enlargement promotes flow reversal in the left pulmonary artery.

PubMed

Kato, Atsuko; Drolet, Christian; Yoo, Shi-Joon; Redington, Andrew N; Grosse-Wortmann, Lars

2016-06-07

The left pulmonary artery (LPA) contributes more than the right (RPA) to total pulmonary regurgitation (PR) in patients after tetralogy of Fallot (TOF) repair, but the mechanism of this difference is not well understood. This study aimed to analyze the interplay between heart and lung size, mediastinal geometry, and differential PR. Forty-eight Cardiovascular Magnetic Resonance (CMR) studies in patients after TOF repair were analyzed. In addition to the routine blood flow and ventricular volume quantification cardiac angle between the thoracic anterior-posterior line and the interventricular septum, right and left lung areas as well as right and left hemithorax areas were measured on an axial image. Statistical analysis was performed to compare flow parameters between RPA and LPA and to assess correlation among right ventricular volume, pulmonary blood flow parameters and lung area. There was no difference between LPA and RPA diameters. The LPA showed significantly less total forward flow (2.49 ± 0.87 L/min/m(2) vs 2.86 ± 0.89 L/min/m(2); p = 0.02), smaller net forward flow (1.40 ± 0.51 vs 1.89 ± 0.60 mL/min/m(2); p = <0.001), and greater regurgitant fraction (RF) (34 ± 10 % vs 43 ± 12 %; p = 0.001) than the RPA. There was no difference in regurgitant flow volume between RPA and LPA (p = 0.29). Indexed right ventricular end-diastolic volume (RVEDVi) correlated with LPA RF (R = 0.48, p < 0.001), but not with RPA RF (p = 0.09). Larger RVEDVi correlated with a more leftward cardiac axis (R = 0.46, p < 0.001) and with smaller left lung area (R = -0.58, p < 0.001). LPA RF, but not RPA RF, correlated inversely with left lung area (R = -0.34, p = 0.02). The follow-up CMRs in 20 patients showed a correlation of the rate of RV enlargement with the rates of LPA RF worsening (R = 0.50, p = 0.03), and of increasing left lung compression (R = -0.55, p = 0.012). An enlarged and levorotated heart is associated with left lung compression and impaired flow into the left lung.

[Pulsatile total cavopulmonary shunt for hypoplastic right heart syndrome with abnormal systemic venous return--a case report].

PubMed

Oiwa, H; Kawauchi, M; Chikada, M; Yagyu, K; Kotsuka, Y; Furuse, A

1995-01-01

A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.

Feasibility of using intensity-modulated radiotherapy to improve lung sparing in treatment planning for distal esophageal cancer.

PubMed

Chandra, Anurag; Guerrero, Thomas M; Liu, H Helen; Tucker, Susan L; Liao, Zhongxing; Wang, Xiaochun; Murshed, Hasan; Bonnen, Mark D; Garg, Amit K; Stevens, Craig W; Chang, Joe Y; Jeter, Melinda D; Mohan, Radhe; Cox, James D; Komaki, Ritsuko

2005-12-01

To evaluate the feasibility whether intensity-modulated radiotherapy (IMRT) can be used to reduce doses to normal lung than three-dimensional conformal radiotherapy (3 DCRT) in treating distal esophageal malignancies. Ten patient cases with cancer of the distal esophagus were selected for a retrospective treatment-planning study. IMRT plans using four, seven, and nine beams (4B, 7B, and 9B) were developed for each patient and compared with the 3 DCRT plan used clinically. IMRT and 3 DCRT plans were evaluated with respect to PTV coverage and dose-volumes to irradiated normal structures, with statistical comparison made between the two types of plans using the Wilcoxon matched-pair signed-rank test. IMRT plans (4B, 7B, 9B) reduced total lung volume treated above 10 Gy (V(10)), 20 Gy (V(20)), mean lung dose (MLD), biological effective volume (V(eff)), and lung integral dose (P<0.05). The median absolute improvement with IMRT over 3DCRT was approximately 10% for V(10), 5% for V(20), and 2.5 Gy for MLD. IMRT improved the PTV heterogeneity (P<0.05), yet conformity was better with 7B-9B IMRT plans. No clinically meaningful differences were observed with respect to the irradiated volumes of spinal cord, heart, liver, or total body integral doses. Dose-volume of exposed normal lung can be reduced with IMRT, though clinical investigations are warranted to assess IMRT treatment outcome of esophagus cancers.

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Lee, Wesley; Chaiworapongsa, Tinnakorn; Espinoza, Jimmy; Schoen, Mary Lou; Falkensammer, Peter; Treadwell, Marjorie; Romero, Roberto

2003-12-01

This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC). Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique. Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.

Implications of free breathing motion assessed by 4D-computed tomography on the delivered dose in radiotherapy for esophageal cancer.

PubMed

Duma, Marciana Nona; Berndt, Johannes; Rondak, Ina-Christine; Devecka, Michal; Wilkens, Jan J; Geinitz, Hans; Combs, Stephanie Elisabeth; Oechsner, Markus

2015-01-01

The aim of this study was to assess the effect of breathing motion on the delivered dose in esophageal cancer 3-dimensional (3D)-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT). We assessed 16 patients with esophageal cancer. All patients underwent 4D-computed tomography (4D-CT) for treatment planning. For each of the analyzed patients, 1 3D-CRT, 1 IMRT, and 1 VMAT (RapidArc-RA) plan were calculated. Each of the 3 initial plans was recalculated on the 4D-CT (for the maximum free inspiration and maximum free expiration) to assess the effect of breathing motion. We assessed the minimum dose (Dmin) and mean dose (Dmean) to the esophagus within the planning target volume, the volume changes of the lungs, the Dmean and the total lung volume receiving at least 40Gy (V40), and the V30, V20, V10, and V5. For the heart we assessed the Dmean and the V25. Over all techniques and all patients the change in Dmean as compared with the planned Dmean (planning CT [PCT]) to the esophagus was 0.48% in maximum free inspiration (CT_insp) and 0.55% in maximum free expiration (CT_exp). The Dmin CT_insp change was 0.86% and CT_exp change was 0.89%. The Dmean change of the lungs (heart) was in CT_insp 1.95% (2.89%) and 3.88% (2.38%) in CT_exp. In all, 4 patients had a clinically relevant change of the dose (≥ 5% Dmean to the heart and the lungs) between inspiration and expiration. These patients had a very cranially or caudally situated tumor. There are no relevant differences in the delivered dose to the regions of interest among the 3 techniques. Breathing motion management could be considered to achieve a better sparing of the lungs or heart in patients with cranially or caudally situated tumors. Copyright © 2015 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

FIVE-YEAR RESULTS OF ADJUVANT RADIOTHER

PubMed Central

Osa, Etin-Osa O.; DeWyngaert, Keith; Roses, Daniel; Speyer, James; Guth, Amber; Axelrod, Deborah; Kerimian, Maria Fenton; Goldberg, Judith D.; Formenti, Silvia C.

2015-01-01

Purpose/Objective A technique of prone breast radiotherapy delivered by a regimen of accelerated intensity modulated radiation therapy (IMRT) with a concurrent boost to the tumor bed, was developed at our institution. We report the five year results of this approach. Methods and Materials Between 2003–2006, 404 patients with Stage I–II breast cancer were prospectively enrolled into two consecutive protocols, institutional trials 03–30 and 05–181, that used the same regimen of 40.5Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5Gy (total dose=48Gy). All patients were treated after segmental mastectomy, had negative margins, and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine set-up attempted, and chosen if found to better spare these organs. Results 92% of patients were treated prone, 8% supine. 72% had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 –228.27cc, mean: 19.65cc. In-field heart volume for left breast cancer patients ranged from 0–21.24cc, mean: 1.59cc. There was no heart in the field for right breast cancer patients. At a median follow-up of five years, the five-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% CI: 0.65–1.04). The five-year cumulative incidence of regional recurrence was 0.53% (95% CI:0.41–0.69) and the five-year overall cumulative death rate was 1.28% (95% CI: 0.48–3.38). 82% (95% CI: 77–85) of patients judged their final cosmetic result as excellent/good. Conclusions Prone accelerated IMRT with a concomitant boost results in excellent local control, optimal sparing of heart and lung, with good cosmesis. RTOG 10–05, a phase III, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and fractionation approach to standard six weeks radiotherapy with a sequential boost. PMID:24867535

Implications of free breathing motion assessed by 4D-computed tomography on the delivered dose in radiotherapy for esophageal cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duma, Marciana Nona, E-mail: Marciana.Duma@mri.tum.de; Berndt, Johannes; Rondak, Ina-Christine

2015-01-01

The aim of this study was to assess the effect of breathing motion on the delivered dose in esophageal cancer 3-dimensional (3D)-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT). We assessed 16 patients with esophageal cancer. All patients underwent 4D-computed tomography (4D-CT) for treatment planning. For each of the analyzed patients, 1 3D-CRT, 1 IMRT, and 1 VMAT (RapidArc—RA) plan were calculated. Each of the 3 initial plans was recalculated on the 4D-CT (for the maximum free inspiration and maximum free expiration) to assess the effect of breathing motion. We assessed the minimum dose (D{sub min})more » and mean dose (D{sub mean}) to the esophagus within the planning target volume, the volume changes of the lungs, the D{sub mean} and the total lung volume receiving at least 40 Gy (V{sub 40}), and the V{sub 30}, V{sub 20}, V{sub 10}, and V{sub 5}. For the heart we assessed the D{sub mean} and the V{sub 25}. Over all techniques and all patients the change in D{sub mean} as compared with the planned D{sub mean} (planning CT [PCT]) to the esophagus was 0.48% in maximum free inspiration (CT-insp) and 0.55% in maximum free expiration (CT-exp). The D{sub min} CT-insp change was 0.86% and CT-exp change was 0.89%. The D{sub mean} change of the lungs (heart) was in CT-insp 1.95% (2.89%) and 3.88% (2.38%) in CT-exp. In all, 4 patients had a clinically relevant change of the dose (≥ 5% D{sub mean} to the heart and the lungs) between inspiration and expiration. These patients had a very cranially or caudally situated tumor. There are no relevant differences in the delivered dose to the regions of interest among the 3 techniques. Breathing motion management could be considered to achieve a better sparing of the lungs or heart in patients with cranially or caudally situated tumors.« less

Airway Complications of Total Artificial Heart.

PubMed

Pathak, Vikas; Donovan, Colin; Malhotra, Rajiv

2017-02-01

The total artificial heart is the mechanical device which is used as a bridge to the heart transplant in patients with biventricular failure. Due to the mechanical nature of the device, patients receiving total artificial heart (TAH) require to be on anticoagulation therapy. Hemorrhage and coagulopathy are few of the known complications of TAH.

Heart failure - surgeries and devices

MedlinePlus

... right ventricular assist devices (RVAD) or a total artificial hearts. They are considered for use if you have ... be on a heart-lung bypass machine. Total artificial hearts are being developed, but are not yet in ...

Exploring for the safer ventilation method in laparoscopic urologic patients? Conventional or low tidal?

PubMed

Ela, Yüksel; Bakı, Elif Doğan; Ateş, Mutlu; Kokulu, Serdar; Keleş, İbrahim; Karalar, Mustafa; Şenay, Hasan; Sıvacı, Remziye Gül

2014-11-01

To study the effects of low tidal volume with positive end-expiratory pressure (PEEP) on arterial blood gases of patients undergoing laparoscopic urologic surgeries. Eighty-six laparoscopic urologic patients were enrolled in this study. Patients were randomized into two groups according to the ventilatory settings. In the conventional group (Group C) (n=43), the tidal volume was 10 mL/kg, and the PEEP was set at 0 cm of H2O. In the low tidal volume with PEEP group (Group LP), the tidal volume was 6 mL/kg, with PEEP of 5 cm of H2O. In both groups total minute volume was 6 L/kg. Peak and plateau airway pressure (PPEAK and PPLAT, respectively) and arterial blood gases were recorded before pneumoperitoneum (PNP) (T1) and the first and third hour (T3) after PNP induction and also after extubation in the intensive care unit. Additionally, heart rate, mean arterial pressure, and peripheral O2 saturation of hemoglobin were recorded. Heart rate, PPEAK, and PPLAT values were similar in both groups. Partial arterial O2 pressure values measured postoperatively were significantly higher in Group LP, whereas those measured before PNP induction were similar (P=.014 and P=.056, respectively). Compared with the baseline, partial arterial CO2 pressure values measured at T1 and at T3 after PNP induction were significantly higher in Group C than in Group LP (P<.001). The pH values of Group C at T1 and at T3 postoperatively were significantly lower than the values of Group LP (P<.001). Extubation times were significantly lower in Group LP. The results of the present study suggest that low tidal volume with PEEP application may be a good alternative for preventing high CO2 levels and yielding better oxygenation and lower extubation times in patients undergoing prolonged laparoscopic urology.

SU-G-TeP1-11: Predictors of Cardiac and Lung Dose Sparing in DIBH for Left Breast Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, N; Kalet, A; Fang, L

Purpose: This retrospective study of left sided whole breast radiation therapy (RT) patients investigates possible predictive parameters correlating to cardiac and left lung dose sparing by deep inspiration breath-hold (DIBH) technique compared to free-breathing (FB). Methods: Thirty-one patients having both DIBH and FB CT scans were included in the study. All patients were planned with a standard step-and-shoot tangential technique using MV photons, with prescription of 50Gy or 50.4Gy. The displacement of the breath hold sternal mark during DIBH, the cardiac contact distances of the axial (CCDax) and parasagittal (CCDps) planes, and lateral-heart-to-chest (LHC) distance on FB CT scans weremore » measured. Lung volumes, mean dose and dose-volume histograms (V5, V10 and V20) were analyzed and compared for heart and left lung for both FB and DIBH techniques. Correlation analysis was performed to identify the predictors for heart and left lung dose sparing. Two-tailed Student’s t-test and linear regression were used for data analysis with significance level of P≤0.05. Results: All dosimetric metrics for the heart and left lung were significantly reduced (P<0.01) with DIBH. Breath hold sternal mark displacement ranged from 0.4–1.8 cm and correlated with mean (P=0.05) and V5 (P=0.02) of heart dose reduction by DIBH. FB lung volume showed correlation with mean lung dose reduction by DIBH (P<0.01). The FB-CCDps and FB-LHC distance had strong positive and negative correlation with FB mean heart dose (P<0.01) and mean heart dose reduction by DIBH (P<0.01), respectively. FB-CCDax showed no correlation with dosimetric changes. Conclusion: DIBH technique has been shown to reduce dose to the heart and left lung. In this patient cohort, FB-CCDps, FB-LHC distance, and FB lung volume served as significant predictors for heart and left lung. These parameters can be further investigated to be used as a tool to better select patients who will benefit from DIBH.« less

Total donor ischemic time: relationship to early hemodynamics and intensive care morbidity in pediatric cardiac transplant recipients.

PubMed

Rodrigues, Warren; Carr, Michelle; Ridout, Deborah; Carter, Katherine; Hulme, Sara Louise; Simmonds, Jacob; Elliott, Martin; Hoskote, Aparna; Burch, Michael; Brown, Kate L

2011-11-01

Single-center studies have failed to link modest increases in total donor ischemic time to mortality after pediatric orthotopic heart transplant. We aimed to investigate whether prolonged total donor ischemic time is linked to pediatric intensive care morbidity after orthotopic heart transplant. Retrospective cohort review. Tertiary pediatric transplant center in the United Kingdom. Ninety-three pediatric orthotopic heart transplants between 2002 and 2006. Total donor ischemic time was investigated for association with early post-orthotopic heart transplant hemodynamics and intensive care unit morbidities. Of 43 males and 50 females with median age 7.2 (interquartile range 2.2, 13.0) yrs, 62 (68%) had dilated cardiomyopathy, 20 (22%) had congenital heart disease, and nine (10%) had restrictive cardiomyopathy. The mean total donor ischemic time was 225.9 (sd 65.6) mins. In the first 24 hrs after orthotopic heart transplant, age-adjusted mean arterial blood pressure increased (p < .001), mean pulmonary arterial pressure fell (p = .012), but central venous pressure (p = .58) and left atrial pressure (p = .20) were unchanged. After adjustment for age, primary diagnosis, pre-orthotopic heart transplant mechanical support, and marginal donor factors, longer total donor ischemic time was significantly associated with lower mean arterial blood pressure (p < .001) in the first 24 hrs after orthotopic heart transplant, longer post-orthotopic heart transplant mechanical ventilation (p = .03), longer post-orthotopic heart transplant stay in the intensive care unit (p = .004), and longer post-orthotopic heart transplant stay in hospital (p = .02). Total donor ischemic time was not related to levels of mean pulmonary arterial pressure (p = .62), left atrial pressure (p = .38), or central venous pressure (p = .76) early after orthotopic heart transplant. Prolonged total donor ischemic time has an adverse effect on the donor organ, contributing to lower mean arterial blood pressure, as well as more prolonged ventilation and intensive care unit and hospital stays post-orthotopic heart transplant, reflecting increased morbidity.

Heart rate variability and aerobic fitness.

PubMed

De Meersman, R E

1993-03-01

Heart rate variability, a noninvasive marker of parasympathetic activity, diminishes with aging and is augmented after exercise training. Whether habitual exercise over time can attenuate this loss is unknown. This cross-sectional investigation compared 72 male runners, aged 15 to 83 to 72 age- and weight-matched sedentary control subjects for the amplitude of their heart rate variability. Heart rate variability was assessed during rest while subjects were breathing at a rate of 6 breaths per minute and at an augmented tidal volume (tidal volume = 30% of vital capacity). Fitness levels were assessed with on-line, open-circuit spirometry while subjects were performing an incremental stress test. Overall results between the two groups showed that the physically active group had significantly higher fitness levels (p < 0.001), which were associated with significantly higher levels of heart rate variability, when compared with their sedentary counterparts (p < 0.001). These findings provide suggestive evidence for habitual aerobic exercise as a beneficial modulator of heart rate variability in an aging population.

The association of pericardial fat with incident coronary heart disease: the Multi-Ethnic Study of Atherosclerosis (MESA).

PubMed

Ding, Jingzhong; Hsu, Fang-Chi; Harris, Tamara B; Liu, Yongmei; Kritchevsky, Stephen B; Szklo, Moyses; Ouyang, Pamela; Espeland, Mark A; Lohman, Kurt K; Criqui, Michael H; Allison, Matthew; Bluemke, David A; Carr, J Jeffrey

2009-09-01

Pericardial fat (ie, fat around the heart) may have a direct role in the atherosclerotic process in coronary arteries through local release of inflammation-related cytokines. Cross-sectional studies suggest that pericardial fat is positively associated with coronary artery disease independent of total body fat. We investigated whether pericardial fat predicts future coronary heart disease events. We conducted a case-cohort study in 998 individuals, who were randomly selected from 6814 Multi-Ethnic Study of Atherosclerosis (MESA) participants and 147 MESA participants (26 from those 998 individuals) who developed incident coronary heart disease from 2000 to 2005. The volume of pericardial fat was determined from cardiac computed tomography at baseline. The age range of the subjects was 45-84 y (42% men, 45% white, 10% Asian American, 22% African American, and 23% Hispanic). Pericardial fat was positively correlated with both body mass index (correlation coefficient = 0.45, P < 0.0001) and waist circumference (correlation coefficient = 0.57, P < 0.0001). In unadjusted analyses, pericardial fat (relative hazard per 1-SD increment: 1.33; 95% CI: 1.15, 1.54), but not body mass index (1.00; 0.84, 1.18), was associated with the risk of coronary heart disease. Waist circumference (1.14; 0.97, 1.34; P = 0.1) was marginally associated with the risk of coronary heart disease. The relation between pericardial fat and coronary heart disease remained significant after further adjustment for body mass index and other cardiovascular disease risk factors (1.26; 1.01, 1.59). The relation did not differ by sex. Pericardial fat predicts incident coronary heart disease independent of conventional risk factors, including body mass index.

Knowledge-based reconstruction for measurement of right ventricular volumes on cardiovascular magnetic resonance images in a mixed population.

PubMed

Pieterman, Elise D; Budde, Ricardo P J; Robbers-Visser, Daniëlle; van Domburg, Ron T; Helbing, Willem A

2017-09-01

Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital heart disease with conventional analysis. © 2017 Wiley Periodicals, Inc.

Identification of Pulmonary Hypertension Caused by Left-Sided Heart Disease (World Health Organization Group 2) Based on Cardiac Chamber Volumes Derived From Chest CT Imaging.

PubMed

Aviram, Galit; Rozenbaum, Zach; Ziv-Baran, Tomer; Berliner, Shlomo; Topilsky, Yan; Fleischmann, Dominik; Sung, Yon K; Zamanian, Roham T; Guo, Haiwei Henry

2017-10-01

Evaluations of patients with pulmonary hypertension (PH) commonly include chest CT imaging. We hypothesized that cardiac chamber volumes calculated from the same CT scans can yield additional information to distinguish PH related to left-sided heart disease (World Health Organization group 2) from other PH subtypes. Patients who had PH confirmed by right heart catheterization and contrast-enhanced chest CT studies were enrolled in this retrospective multicenter study. Cardiac chamber volumes were calculated using automated segmentation software and compared between group 2 and non-group 2 patients with PH. This study included 114 patients with PH, 27 (24%) of whom were classified as group 2 based on their pulmonary capillary wedge pressure. Patients with group 2 PH exhibited significantly larger median left atrial (LA) volumes (118 mL vs 63 mL; P < .001), larger median left ventricular (LV) volumes (90 mL vs 76 mL; P = .02), and smaller median right ventricular (RV) volumes (173 mL vs 210 mL; P = .005) than did non-group 2 patients. On multivariate analysis adjusted for age, sex, and mean pulmonary arterial pressure, group 2 PH was significantly associated with larger median LA and LV volumes (P < .001 and P = .008, respectively) and decreased volume ratios of RA/LA, RV/LV, and RV/LA (P = .001, P = .004, and P < .001, respectively). Enlarged LA volumes demonstrated a high discriminatory ability for group 2 PH (area under the curve, 0.92; 95% CI, 0.870-0.968). Volumetric analysis of the cardiac chambers from nongated chest CT scans, particularly with findings of an enlarged left atrium, exhibited high discriminatory ability for identifying patients with PH due to left-sided heart disease. Copyright © 2017. Published by Elsevier Inc.

Aroma profile design of wine spirits: Multi-objective optimization using response surface methodology.

PubMed

Matias-Guiu, Pau; Rodríguez-Bencomo, Juan José; Pérez-Correa, José R; López, Francisco

2018-04-15

Developing new distillation strategies can help the spirits industry to improve quality, safety and process efficiency. Batch stills equipped with a packed column and an internal partial condenser are an innovative experimental system, allowing a fast and flexible management of the rectification. In this study, the impact of four factors (heart-cut volume, head-cut volume, pH and cooling flow rate of the internal partial condenser during the head-cut fraction) on 18 major volatile compounds of Muscat spirits was optimized using response surface methodology and desirability function approaches. Results have shown that high rectification at the beginning of the heart-cut enhances the overall positive aroma compounds of the product, reducing off-flavor compounds. In contrast, optimum levels of heart-cut volume, head-cut volume and pH factors varied depending on the process goal. Finally, three optimal operational conditions (head off-flavors reduction, flowery terpenic enhancement and fruity ester enhancement) were evaluated by chemical and sensory analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Current state of total artificial heart therapy and introduction of the most important total artificial heart systems.

PubMed

Spiliopoulos, Sotirios; Hergesell, Vera; Wasler, Andrae; Dapunt, Otto

2018-06-14

Due to the declining instances of organ donation, total artificial heart (TAH) therapy is of increasing importance for the management of end-stage biventricular heart failure. We introduce the currently most important established and novel TAH systems (SynCardia, CARMAT, ReinHeart, BiVACOR), report clinical outcomes and discuss technical requirements for the successful implementation of TAH therapy as an alternative to cardiac transplantation.

Radiation-induced cardiomyopathy as a function of radiation beam gating to the cardiac cycle

NASA Astrophysics Data System (ADS)

Gladstone, David J.; Flanagan, Michael F.; Southworth, Jean B.; Hadley, Vaughn; Thibualt, Melissa Wei; Hug, Eugen B.; Hoopes, P. Jack

2004-04-01

Portions of the heart are often unavoidably included in the primary treatment volume during thoracic radiotherapy, and radiation-induced heart disease has been observed as a treatment-related complication. Such complications have been observed in humans following radiation therapy for Hodgkin's disease and treatment of the left breast for carcinoma. Recent attempts have been made to prevent re-stenosis following angioplasty procedures using external beam irradiation. These attempts were not successful, however, due to the large volume of heart included in the treatment field and subsequent cardiac morbidity. We suggest a mechanism for sparing the heart from radiation damage by synchronizing the radiation beam with the cardiac cycle and delivering radiation only when the heart is in a relatively hypoxic state. We present data from a rat model testing this hypothesis and show that radiation damage to the heart can be altered by synchronizing the radiation beam with the cardiac cycle. This technique may be useful in reducing radiation damage to the heart secondary to treatment for diseases such as Hodgkin's disease and breast cancer.

Relation of plasma aldosterone concentration to diuretic treatment in patients with severe heart disease.

PubMed Central

Knight, R K; Miall, P A; Hawkins, L A; Dacombe, J; Edwards, C R; Hamer, J

1979-01-01

To assess the relation of hyperaldosteronism and potassium depletion to the intensity of diuretic therapy we have measured plasma aldosterone by radioimmunoassay and total exchangeable potassium by radioisotope dilution in 24 patients when they were stable at the end of their preparation for cardiac operation. Some patients required intensive frusemide therapy to reach an optimal state for operation and many showed hyperaldosteronism. Plasma aldosterone was significantly related to daily dose of frusemide (r=0.77). Depletion of total exchangeable potassium expressed in terms of predicted weight was significantly related to plasma aldosterone (r= -0.64). The reduction in total exchangeable potassium is interpreted as chiefly related to loss of lean tissue mass from the wasting that leads to cardiac cachexia, but evidence is presented on the basis of measurements of extracellular fluid volume as sulphate space (20 patients) of entry of sodium into the cells which may indicate a true cellular potassium loss. Although plasma potassium is usually easily maintained with oral potassium supplements or aldosterone antagonists, we postulate that intensive diuretic therapy in severe heart disease may provoke hyperaldosteronism which accentuates potassium loss and may contribute to wasting and to intracellular potassium depletion in critical tissue, such as myocardium. PMID:508454

Reappearance of beriberi heart disease in Japan. A study of 23 cases.

PubMed

Kawai, C; Wakabayashi, A; Matsumura, T; Yui, Y

1980-09-01

Twenty-three Japanese patients with beriberi heart disease, 17 of them teenagers, were studied. The recent tendency for teenagers to take excessive sweet carbonated soft drinks, instant noodles and powermill-polished rice readily induces relative thiamine deficiency. A sudden increase in thiamine requirements due to strenuous exercise can result in overt beriberi heart disease. Alcohol had nothing to do with the development of the disease. Characteristic features commonly seen in teenage patients include peripheral edema, low peripheral vascular resistance, increased venous pressure enlarged heart, T wave abnormalities, hyperkinetic circulatory state and increased circulating blood volume. Thiamine deficiency was confirmed by a decrease in blood thiamine concentration, a decrease in erythrocyte transketolase activity and an increase in thiamine pyrophosphate (TPP) effect. Improvement was rapidly achieved with thiamine administration, balanced nutrition and rest, especially in the teenage patients. Increased circulating blood volume was useful in differentiating beriberi heart disease from hyperthyroidism.

Left Ventricular Reverse Remodeling With Biventricular Versus Right Ventricular Pacing in Patients With Atrioventricular Block and Heart Failure in the BLOCK HF Trial.

PubMed

St John Sutton, Martin; Plappert, Ted; Adamson, Philip B; Li, Pei; Christman, Shelly A; Chung, Eugene S; Curtis, Anne B

2015-05-01

Biventricular pacing in heart failure (HF) improves survival, relieves symptoms, and attenuates left ventricular (LV) remodeling. However, little is known about biventricular pacing in HF patients with atrioventricular block because they are typically excluded from biventricular trials. The Biventricular versus Right Ventricular Pacing in Heart Failure Patients with Atrioventricular Block (BLOCK HF) trial randomized patients with atrioventricular block, New York Heart Association symptom classes I to III HF, and LV ejection fraction ≤50% to biventricular or right ventricular pacing. Doppler echocardiograms were obtained at randomization (after 30 to 60 days of right ventricular pacing postimplant) and every 6 months through 24 months. Data analysis comparing changes in 10 prespecified echo parameters over time was conducted using a Bayesian design. LV end systolic volume index was also evaluated as a predictor of mortality/morbidity. Of 691 randomized subjects, 624 had paired Doppler echocardiogram data for ≥1 analyses at 6, 12, 18, or 24 months. Biventricular pacing significantly reduced LV volume indices and intraventricular mechanical delay, and improved LV ejection fraction, consistent with LV reverse remodeling. These parameters showed little change with right ventricular pacing alone, indicating no systematic reverse remodeling with right ventricular pacing. LV end systolic volume index was predictive of mortality/morbidity; the estimated risk increased up to 1% for every 1 mL/m(2) increase in LV end systolic volume index. LV end systolic volume index is a significant predictor of mortality/morbidity in this population. Cardiac structure and function are improved with biventricular pacing for patients with atrioventricular block and LV systolic dysfunction. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00267098. © 2015 American Heart Association, Inc.

Force properties of skinned cardiac muscle following increasing volumes of aerobic exercise in rats.

PubMed

Boldt, Kevin Rudi; Rios, Jaqueline Lourdes; Joumaa, Venus; Herzog, Walter

2018-05-03

The positive effects of chronic endurance exercise training on health and performance have been well documented. These positive effects have been evaluated primarily at the structural level, and work has begun to evaluate mechanical adaptations of the myocardium. However, it remains poorly understood how the volume of exercise training affects cardiac adaptation. In order to gain some understanding, we subjected three-month-old Sprague-Dawley rats (N=23) to treadmill running for eleven weeks at one of three exercise volumes (moderate, high, and extra high). Following training, hearts were excised and mechanical testing was completed on skinned trabecular fiber bundles. Performance on a maximal fitness test was dose-dependent upon training volume, where greater levels of training led to greater performance. No differences were observed between animals from any group for active stress production. Heart mass and passive stress increases in a dose-dependent manner for animals in the control, moderate, and high duration groups. However, hearts from animals in the extra high duration group presented with inhibited responses for heart mass and passive stress, despite performing greatest on a graded treadmill fitness test. These results suggest that heart mass and passive stress adapt in a dose-dependent manner, until exercise becomes excessive and adaptation is inhibited. Our findings are in agreement with the beneficial role exercise has in cardiac adaptation. However, excessive exercise comes with risks of maladaptation which must be weighed against the desire to increase performance.

Major adverse events and atrial tachycardia in Ebstein’s anomaly predicted by cardiovascular magnetic resonance

PubMed Central

Rydman, Riikka; Shiina, Yumi; Diller, Gerhard-Paul; Niwa, Koichiro; Li, Wei; Uemura, Hideki; Uebing, Anselm; Barbero, Umberto; Bouzas, Beatriz; Ernst, Sabine; Wong, Tom; Pennell, Dudley J; Gatzoulis, Michael A; Babu-Narayan, Sonya V

2018-01-01

Objectives Patients with Ebstein’s anomaly of the tricuspid valve (EA) are at risk of tachyarrhythmia, congestive heart failure and sudden cardiac death. We sought to determine the value of cardiovascular magnetic resonance (CMR) for predicting these outcomes. Methods Seventy-nine consecutive adult patients (aged 37±15 years) with unrepaired EA underwent CMR and were followed prospectively for a median 3.4 (range 0.4–10.9) years for clinical outcomes, namely major adverse cardiovascular events (MACEs: sustained ventricular tachycardia/heart failure hospital admission/cardiac transplantation/death) and first-onset atrial tachyarrhythmia (AT). Results CMR-derived variables associated with MACE (n=6) were right ventricular (RV) or left ventricular (LV) ejection fraction (EF) (HR 2.06, 95% CI 1.168 to 3.623, p=0.012 and HR 2.35, 95% CI 1.348 to 4.082, p=0.003, respectively), LV stroke volume index (HR 2.82, 95% CI 1.212 to 7.092, p=0.028) and cardiac index (HR 1.71, 95% CI 1.002 to 1.366, p=0.037); all remained significant when tested solely for mortality. History of AT (HR 11.16, 95% CI 1.30 to 95.81, p=0.028) and New York Heart Association class >2 (HR 7.66, 95% CI 1.54 to 38.20, p=0.013) were also associated with MACE; AT preceded all but one MACE, suggesting its potential role as an early marker of adverse outcome (p=0.011). CMR variables associated with first-onset AT (n=17; 21.5%) included RVEF (HR 1.55, 95% CI 1.103 to 2.160, p=0.011), total R/L volume index (HR 1.18, 95% CI 1.06 to 1.32, p=0.002), RV/LV end diastolic volume ratio (HR 1.55, 95% CI 1.14 to 2.10, p=0.005) and apical septal leaflet displacement/total LV septal length (HR 1.03, 95% CI 1.00 to 1.07, p=0.041); the latter two combined enhanced risk prediction (HR 6.12, 95% CI 1.67 to 22.56, p=0.007). Conclusion CMR-derived indices carry prognostic information regarding MACE and first-onset AT among adults with unrepaired EA. CMR may be included in the periodic surveillance of these patients. PMID:28684436

SU-E-T-625: Potential for Reduced Radiation Induced Toxicity for the Treatment of Inoperable Non-Small-Cell Lung Cancer Using RapidArc Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokhrel, D; Sood, S; Badkul, R

2015-06-15

Purpose: To investigate the feasibility of using RapidArc (RA) treatment planning to reduce irradiation volume of normal lung and other organs at risk (OARs) in the treatment of inoperable non-small-cell lung cancer (NSCLC) patients. Methods: A retrospective treatment planning and delivery study was performed to compare target coverage and the volumes of the normal lung, spinal cord, heart and esophagus on 4D-CT scan above their dose tolerances delivered by RA vs. IMRT for ten inoperable NSCLC patients (Stage I-IIIB). RA plans consisted of either one-full or two-partial co-planar arcs used to treat 95% of the planning target volume (PTV) withmore » 6MV beam to a prescription of 66Gy in 33 fractions. IMRT plans were generated using 5–7 co-planar fields with 6MV beam. PTV coverage, dose-volume histograms, homogeneity/conformity indices (CI), total number of monitor units(MUs), beam-on time and delivery accuracy were compared between the two treatment plans. Results: Similar target coverage was obtained between the two techniques. RA (CI=1.02) provided more conformal plans without loss of homogeneity compared to IMRT plans (CI=1.12). Compared to IMRT, RA achieved a significant median dose reduction in V10 (3%), V20 (8%), and mean lung dose (3%) on average, respectively. On average, V5 was comparable between the two treatment plans. RA reduced mean esophagus (6%), mean heart (18%), and maximum spinal cord dose (7%), on average, respectively. Total number of MUs and beam-on time were each reduced almost by a factor of 2 when compared to IMRT-patient comfort, reduced intra-fraction-motion and leakage dose. The average IMRT and RA QA pass rate was about 98% for both types of plans for 3%/3mm criterion. Conclusion: Compared to IMRT plans, RA provided not only comparable target coverage, but also improved conformity, treatment time, and significant reduction in irradiation of OARs. This may potentially allow for target dose escalation without increase in normal tissue toxicity.« less

Response and adaptation of Beagle dogs to hypergravity

NASA Technical Reports Server (NTRS)

Oyama, J.

1975-01-01

Eight male Beagle dogs, five months old, were centrifuged continuously for three months at progressively increasing loads. Heart rate and deep body temperature were monitored continuously by implant biotelemetry. Initially, centrifuged dogs showed transient decreases in heart rate and body temperature along with changes in their diurnal rhythm patterns. Compared with normal gravity controls, exposed dogs showed a slower growth rate and a reduced amount of body fat. Blood protein, total lipids, cholesterol, calcium, packed cell volume, red blood cell count, and hemoglobin were also decreased significantly. Absolute weights of the leg bones of centrifuged dogs were significantly greater than controls. Photon absorptiometry revealed significant density increases in selective regions of the femur and humerus of centrifuged dogs. In spite of the various changes noted, results from this and other studies affirm the view that dogs can tolerate and adapt to sustained loads as high as 2.5 g without serious impairment of their body structure and function.

Cardiovascular responses of women to lower body negative pressure

NASA Technical Reports Server (NTRS)

Frey, M. A. B.; Mathes, K. L.; Hoffler, G. W.

1986-01-01

The effects of lower body negative pressure (LBNP) on the cardiovascular response of 20 women between 23-43 years are evaluated. Calf circumference and cardiovascular data were recorded for women in the follicular and luteal phases of the menstrual cycle at -30, -40, and -50 mm Hg LBNP. The data reveal that the two menstrual phases did not cause differences in the way women respond to LBNP. It is observed that during LBNP calf circumference is enlarged; transthoracic impedance, and heart rate are increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure, and cardiac output are reduced; and total peripheral resistance is elevated. The experimental data are compared to Montgomery et al. (1979). It is noted that the response of women to -50 mm Hg LBNP is similar to that of men; however, women adapt to stresses on the cardiovascular system with greater heart rate adjustments.

Feasibility of single-beat full-volume capture real-time three-dimensional echocardiography for quantification of right ventricular volume: validation by cardiac magnetic resonance imaging.

PubMed

Zhang, Quan Bin; Sun, Jing Ping; Gao, Rui Feng; Lee, Alex Pui-Wai; Feng, Yan Lin; Liu, Xiao Rong; Sheng, Wei; Liu, Feng; Yang, Xing Sheng; Fang, Fang; Yu, Cheuk-Man

2013-10-09

The lack of an accurate noninvasive method for assessing right ventricular (RV) volume and function has been a major deficiency of two-dimensional (2D) echocardiography. The aim of our study was to test the feasibility of single-beat full-volume capture with real-time three-dimensional echo (3DE) imaging system for the evaluation of RV volumes and function validated by cardiac magnetic resonance imaging (CMRI). Sixty-one subjects (16 normal subjects, 20 patients with hypertension, 16 patients with pulmonary heart disease and 9 patients with coronary heart disease) were studied. RV volume and function assessments using 3DE were compared with manual tracing with CMRI as the reference method. Fifty-nine of 61 patients (96.7%; 36 male, mean age, 62 ± 15 years) had adequate three-dimensional echocardiographic data sets for analysis. The mean RV end diastolic volume (EDV) was 105 ± 38 ml, end-systolic volume (ESV) was 60 ± 30 and RV ejection fraction (EF) was 44 ± 11% by CMRI; and EDV 103 ± 38 ml, ESV 60 ± 28 ml and RV EF 41 ± 13% by 3DE. The correlations and agreements between measurements estimated by two methods were acceptable. RV volumes and function can be analyzed with 3DE software in most of subjects with or without heart diseases, which is able to be estimated with single-beat full-volume capture with real-time 3DE compared with CMRI. © 2013.

Characterization of cardiac flow in heart disease patients by computational fluid dynamics and 4D flow MRI

NASA Astrophysics Data System (ADS)

Lantz, Jonas; Gupta, Vikas; Henriksson, Lilian; Karlsson, Matts; Persson, Ander; Carhall, Carljohan; Ebbers, Tino

2017-11-01

In this study, cardiac blood flow was simulated using Computational Fluid Dynamics and compared to in vivo flow measurements by 4D Flow MRI. In total, nine patients with various heart diseases were studied. Geometry and heart wall motion for the simulations were obtained from clinical CT measurements, with 0.3x0.3x0.3 mm spatial resolution and 20 time frames covering one heartbeat. The CFD simulations included pulmonary veins, left atrium and ventricle, mitral and aortic valve, and ascending aorta. Mesh sizes were on the order of 6-16 million cells, depending on the size of the heart, in order to resolve both papillary muscles and trabeculae. The computed flow field agreed visually very well with 4D Flow MRI, with characteristic vortices and flow structures seen in both techniques. Regression analysis showed that peak flow rate as well as stroke volume had an excellent agreement for the two techniques. We demonstrated the feasibility, and more importantly, fidelity of cardiac flow simulations by comparing CFD results to in vivo measurements. Both qualitative and quantitative results agreed well with the 4D Flow MRI measurements. Also, the developed simulation methodology enables ``what if'' scenarios, such as optimization of valve replacement and other surgical procedures. Funded by the Wallenberg Foundation.

Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction

PubMed Central

Nelson, O. Lynne; Rourke, Bryan C.

2013-01-01

SUMMARY Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min−1 to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was ~9.5 times longer, and the diastolic phase was 28× longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance of contraction and relaxation for regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal than during the active period, particularly systolic strain, which was 33% of active, compared with the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin heavy-chain (MyHC) isoforms in a separate cohort of squirrels over 5 months, including time points before hibernation, during hibernation and just prior to emergence. Hibernating individuals were maintained in both a 4°C cold room and a 20°C warm room. Measured by SDS-PAGE, relative percentages of cardiac MyHC alpha were increased during hibernation, at both hibernacula temperatures. A potential increase in contractile speed, and power, from more abundant MyHC alpha may aid force generation at low temperature and at low heart rates. Unlike many models of cardiomyopathies where the alpha isoform is replaced by the beta isoform in order to reduce oxygen consumption, ground squirrels demonstrate a potential cardioprotective mechanism to maintain cardiac output during torpor. PMID:24072796

Progression of Coronary Artery Calcium and Incident Heart Failure: The Multi-Ethnic Study of Atherosclerosis.

PubMed

Bakhshi, Hooman; Ambale-Venkatesh, Bharath; Yang, Xiaoying; Ostovaneh, Mohammad R; Wu, Colin O; Budoff, Matthew; Bahrami, Hossein; Wong, Nathan D; Bluemke, David A; Lima, João A C

2017-04-20

Although the association between coronary artery calcium (CAC) and future heart failure (HF) has been shown previously, the value of CAC progression in the prediction of HF has not been investigated. In this study, we investigated the association of CAC progression with subclinical left ventricular (LV) dysfunction and incident HF in the Multi-Ethnic Study of Atherosclerosis. The Multi-Ethnic Study of Atherosclerosis is a population-based study consisting of 6814 men and women aged 45 to 84, free of overt cardiovascular disease at enrollment, who were recruited from 4 ethnicities. We included 5644 Multi-Ethnic Study of Atherosclerosis participants who had baseline and follow-up cardiac computed tomography and were free of HF and coronary heart disease before the second cardiac computed tomography. Mean (±SD) age was 61.7±10.2 years and 47.2% were male. The Cox proportional hazard models and multivariable linear regression models were deployed to determine the association of CAC progression with incident HF and subclinical LV dysfunction, respectively. Over a median follow-up of 9.6 (interquartile range: 8.8-10.6) years, 182 participants developed incident HF. CAC progression of 10 units per year was associated with 3% of increased risk of HF independent of overt coronary heart disease ( P =0.008). In 2818 participants with available cardiac magnetic resonance images, CAC progression was associated with increased LV end diastolic volume (β=0.16; P =0.03) and LV end systolic volume (β=0.12; P =0.006) after excluding participants with any coronary heart disease. CAC progression was associated with incident HF and modestly increased LV end diastolic volume and LV end systolic volume at follow-up exam independent of overt coronary heart disease. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Adipose-Derived Cell Construct Stabilizes Heart Function and Increases Microvascular Perfusion in an Established Infarct

PubMed Central

Nguyen, Quang T.; Touroo, Jeremy S.; Aird, Allison L.; Chang, Raymond C.; Ng, Chin K.; Hoying, James B.; Williams, Stuart K.

2013-01-01

We have previously shown that myocardial infarction (MI) immediately treated with an epicardial construct containing stromal vascular fraction (SVF) from adipose tissue preserved microvascular function and left ventricle contractile mechanisms. In order to evaluate a more clinically relevant condition, we investigated the cardiac recovery potential of an SVF construct implanted onto an established infarct. SVF cells were isolated from rat adipose tissue, plated on Vicryl, and cultured for 14 days. Fischer-344 rats were separated into MI groups: (a) 6-week MI (MI), (b) 6-week MI treated with an SVF construct at 2 weeks (MI SVF), (c) 6-week MI with Vicryl construct at 2 weeks (MI Vicryl), and (d) MI 2wk (time point of intervention). Emax, an indicator of systolic performance and contractile function, was lower in the MI and MI Vicryl versus MI SVF. Positron emission tomography imaging (18F-fluorodeoxyglucose) revealed a decreased percentage of relative infarct volume in the MI SVF versus MI and MI Vicryl. Total vessel count and percentage of perfusion assessed via immunohistochemistry were both increased in the infarct region of MI SVF versus MI and MI Vicryl. Overall cardiac function, percentage of relative infarct, and percentage of perfusion were similar between MI SVF and MI 2wk; however, total vessel count increased after SVF treatment. These data suggest that SVF treatment of an established infarct stabilizes the heart at the time point of intervention by preventing a worsening of cardiac performance and infarcted volume, and is associated with increased microvessel perfusion in the area of established infarct. PMID:24106337

Assessment of butorphanol-azaperone-medetomidine combination as anesthesia for semen collection and evaluation of semen quality in white-tailed deer (Odocoileus virginianus).

PubMed

Kirschner, S M; Rodenkirch, R

2017-09-01

The aim of this current study was to evaluate the level of anesthesia produced by a combination of butorphanol-azaperone-medetomidine (BAM) for semen collection by electroejaculation on captive white-tailed bucks (Odocoileus virginianus). Ten male white-tailed deer, weighing 68.2-115.9kg, ranging in age from one to four years were randomly selected from housing pens and anesthetized with the BAM drug combination at a dose volume of 2.0mL each. Semen was collected from each animal using a standard cervid electroejaculation protocol while under BAM anesthesia. Physiological data was recorded following induction of anesthesia and during semen collection. Collected ejaculates were prepared for analysis using a standard extender protocol for cryopreservation. Eleven sperm viability parameters were quantified for each sample using a Computerized Assisted Sperm Analysis system, including total seminal volume; sperm concentration and total sperm number. kinematic parameters of motile spermatozoa were also assessed. Results demonstrated that BAM provided an effective plane of anesthesia for successful collection of viable sperm. Measured physiological variables of heart rate, respiration and body temperature all remained within safe, normal limits. Data recorded on semen characteristics from all collected ejaculates correlated well with key traits determined to be important for successful fertilization through measurement of total semen volume; sperm concentration; total sperm number; and kinematic parameters of motile spermatozoa. There were no serious adverse events. This field study indicates that BAM anesthesia is suitable for semen collection in white-tailed deer. Copyright © 2017 Elsevier B.V. All rights reserved.

A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

PubMed Central

2012-01-01

Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP) is presented, that measures the average stroke volume (SV) for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition) with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo). These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds). The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling caused a pattern over the thorax quite distinct from that of atrial filling. The in-vivo tests of the HCP with LVot Doppler resulted in a Pearson’s correlation of R = 0.892, and Bland-Altman plotting of SV yielded a mean bias of -1.6 ml and 2SD =14.8 ml. Conclusions The results indicate that the HCP was able to track the changes in ventricular stroke volume reliably. Furthermore, the HCP produced ventricular volume-time curves that were consistent with the literature, and may be a diagnostic tool as well. PMID:22900831

Association of Serum Vitamin D with the Risk of Incident Dementia and Subclinical Indices of Brain Aging: The Framingham Heart Study.

PubMed

Karakis, Ioannis; Pase, Matthew P; Beiser, Alexa; Booth, Sarah L; Jacques, Paul F; Rogers, Gail; DeCarli, Charles; Vasan, Ramachandran S; Wang, Thomas J; Himali, Jayandra J; Annweiler, Cedric; Seshadri, Sudha

2016-01-01

Identifying nutrition- and lifestyle-based risk factors for cognitive impairment and dementia may aid future primary prevention efforts. We aimed to examine the association of serum vitamin D levels with incident all-cause dementia, clinically characterized Alzheimer's disease (AD), MRI markers of brain aging, and neuropsychological function. Framingham Heart Study participants had baseline serum 25-hydroxyvitamin D (25(OH)D) concentrations measured between 1986 and 2001. Vitamin D status was considered both as a continuous variable and dichotomized as deficient (<10 ng/mL), or at the cohort-specific 20th and 80th percentiles. Vitamin D was related to the 9-year risk of incident dementia (n = 1663), multiple neuropsychological tests (n = 1291) and MRI markers of brain volume, white matter hyperintensities and silent cerebral infarcts (n = 1139). In adjusted models, participants with vitamin D deficiency (n = 104, 8% of the cognitive sample) displayed poorer performance on Trail Making B-A (β= -0.03 to -0.05±0.02) and the Hooper Visual Organization Test (β= -0.09 to -0.12±0.05), indicating poorer executive function, processing speed, and visuo-perceptual skills. These associations remained when vitamin D was examined as a continuous variable or dichotomized at the cohort specific 20th percentile. Vitamin D deficiency was also associated with lower hippocampal volumes (β= -0.01±0.01) but not total brain volume, white matter hyperintensities, or silent brain infarcts. No association was found between vitamin D deficiency and incident all-cause dementia or clinically characterized AD. In this large community-based sample, low 25(OH)D concentrations were associated with smaller hippocampal volume and poorer neuropsychological function.

Vasopressin V2 receptor antagonist tolvaptan is effective in heart failure patients with reduced left ventricular systolic function and low blood pressure.

PubMed

Suzuki, Satoshi; Yoshihisa, Akiomi; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Abe, Yukihiko; Saito, Tomiyoshi; Ohwada, Takayuki; Suzuki, Hitoshi; Saitoh, Shu-ichi; Kubota, Isao; Takeishi, Yasuchika

2015-01-01

Diuresis is a major therapy for the reduction of congestive symptoms in acute decompensated heart failure (ADHF) patients. Carperitide has natriuretic and vasodilatory effects, and tolvaptan produces water excretion without electrolyte excretion. We previously reported the usefulness of tolvaptan compared to carperitide in ADHF patients with fluid volume retention. The purpose of this study was to examine whether the efficacy of tolvaptan was altered in ADHF patients with reduced left ventricular systolic function and in those with hypotension. A total of 109 hospitalized ADHF patients were randomly assigned to either a tolvaptan or a carperitide treatment group. Baseline clinical characteristics were not different between the two groups. We divided these patients based on the left ventricular ejection fraction (EF) by echocardiography, and blood pressure (BP) at the time of admission. Daily urine volume between the tolvaptan and carperitide groups in patients with preserved EF (≥ 50%) was not different, however, in those with reduced EF (< 50%), the urine volume was significantly higher in the tolvaptan group than in the carperitide group (day 2, 3, 4, P < 0.05 for all). Daily urine volume did not differ between these two groups in the high blood pressure group (BP ≥ 140 mmHg), but was significantly higher in the tolvaptan group than in the carperitide group (day 1, P = 0.021; day 3, P = 0.017) in the low blood pressure group (BP < 140 mmHg). The present study reveals that tolvaptan is more effective than carperitide, especially in ADHF patients with reduced left ventricular systolic function and without hypertension.

Oxygen-saving effect of a new cardiotonic agent, MCI-154, in diseased human hearts.

PubMed

Mori, M; Takeuchi, M; Takaoka, H; Hata, K; Hayashi, Y; Yamakawa, H; Yokoyama, M

1997-03-01

The aim of this study was to examine the left ventricular mechanoenergetic effects of a novel Ca2+ sensitizing agent, MCI-154, on diseased human hearts compared with dobutamine. Unlike conventional cardiotonic agents, a Ca2+ sensitizer that could produce a positive inotropic action by altering the responsiveness of myofilament to Ca2+ could generate force with smaller amounts of Ca2+; thus, it may potentially save energy expenditure. The left ventricular pressure-volume relation and myocardial oxygen consumption per beat (Vo2) were measured by a conductance (volume) catheter and a Webster catheter. Left ventricular contractility (Emax), systolic pressure-volume area (PVA [index of left ventricular total mechanical energy]) and Vo2 were assessed before and after infusion of MCI-154 or dobut-amine. The PVA-independent Vo2 (Vo2 mainly for excitation-contraction coupling) was assessed as the Vo2 at zero PVA. Both agents increased Emax comparably (dobutamine: from 3.55 +/- 1.10 [mean +/- SD] to 5.04 +/- 1.16 mm Hg/ml per m2, p < 0.0001; MCI-154: from 3.36 +/- 1.26 to 5.37 +/- 2.14 mm Hg/ml per m2, p < 0.0001); dobutamine increased total Vo2 (from 0.22 +/- 0.08 to 0.27 +/- 0.09 ml O2, p < 0.05) and PVA-independent Vo2 (from 0.019 +/- 0.019 to 0.091 +/- 0.051 ml O2, p < 0.005); but MCI-154 did not change these variables significantly. Consequently, the oxygen cost of contractility (delta PVA-independent Vo2/delta Emax) was less with MCI-154 than with dobutamine (0.14 +/- 0.18 vs. 1.10 +/- 0.80 J/mm Hg per ml per m2, p < 0.05). These results suggest that the cardiotonic action mediated by MCI-154 could provide an energetic advantage over the conventional cardiotonic action with currently used inotropic agents.

Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

NASA Technical Reports Server (NTRS)

Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi;

A comparison of hydration effect on body fluid and temperature regulation between Malaysian and Japanese males exercising at mild dehydration in humid heat

PubMed Central

2014-01-01

Background This study investigated the effect of hydration differences on body fluid and temperature regulation between tropical and temperate indigenes exercising in the heat. Methods Ten Japanese and ten Malaysian males with matched physical characteristics (height, body weight, and peak oxygen consumption) participated in this study. Participants performed exercise for 60 min at 55% peak oxygen uptake followed by a 30-min recovery at 32°C and 70% relative air humidity with hydration (4 times each, 3 mL per kg body weight, 37°C) or without hydration. Rectal temperature, skin temperature, heart rate, skin blood flow, and blood pressure were measured continuously. The percentage of body weight loss and total sweat loss were calculated from body weight measurements. The percentage change in plasma volume was estimated from hemoglobin concentration and hematocrit. Results Malaysian participants had a significantly lower rectal temperature, a smaller reduction in plasma volume, and a lower heart rate in the hydrated condition than in the non-hydrated condition at the end of exercise (P <0.05), whereas Japanese participants showed no difference between the two hydration conditions. Hydration induced a greater total sweat loss in both groups (P <0.05), and the percentage of body weight loss in hydrated Malaysians was significantly less than in hydrated Japanese (P <0.05). A significant interaction between groups and hydration conditions was observed for the percentage of mean cutaneous vascular conductance during exercise relative to baseline (P <0.05). Conclusions The smaller reduction in plasma volume and percentage body weight loss in hydrated Malaysians indicated an advantage in body fluid regulation. This may enable Malaysians to reserve more blood for circulation and heat dissipation and thereby maintain lower rectal temperatures in a hydrated condition. PMID:24490869

Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

PubMed Central

Levine, Benjamin D; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Zuckerman, Julie H; Diedrich, André; Biaggioni, Italo; Ray, Chester A; Smith, Michael L; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D; Buckey, Jay C; Cooke, William H; Baisch, Friedhelm J; Robertson, David; Eckberg, Dwain L; Blomqvist, C Gunnar

2002-01-01

Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts ∼72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (± s.e.m.) stroke volume was lower (46 ± 5 vs. 76 ± 3 ml, P = 0.017) and heart rate was higher (93 ± 1 vs. 74 ± 4 beats min−1, P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 ± 256 vs. 1372 ± 62 dynes s cm−5, P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 ± 4 vs. 17 ± 2 bursts min−1, P = 0.04) and tilted (46 ± 4 vs. 38 ± 3 bursts min−1, P = 0.01) positions. A strong (r2 = 0.91–1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal. PMID:11773340

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei Xiong; Liu, H. Helen; Tucker, Susan L.

Purpose: To identify clinical and dosimetric factors influencing the risk of pericardial effusion (PCE) in patients with inoperable esophageal cancer treated with definitive concurrent chemotherapy and radiation therapy (RT). Methods and Materials: Data for 101 patients with inoperable esophageal cancer treated with concurrent chemotherapy and RT from 2000 to 2003 at our institution were analyzed. The PCE was confirmed from follow-up chest computed tomography scans and radiologic reports, with freedom from PCE computed from the end of RT. Log-rank tests were used to identify clinical and dosimetric factors influencing freedom from PCE. Dosimetric factors were calculated from the dose-volume histogrammore » for the whole heart and pericardium. Results: The crude rate of PCE was 27.7% (28 of 101). Median time to onset of PCE was 5.3 months (range, 1.0-16.7 months) after RT. None of the clinical factors investigated was found to significantly influence the risk of PCE. In univariate analysis, a wide range of dose-volume histogram parameters of the pericardium and heart were associated with risk of PCE, including mean dose to the pericardium, volume of pericardium receiving a dose greater than 3 Gy (V3) to greater than 50 Gy (V50), and heart volume treated to greater than 32-38 Gy. Multivariate analysis selected V30 as the only parameter significantly associated with risk of PCE. Conclusions: High-dose radiation to the pericardium may strongly increase the risk of PCE. Such a risk may be reduced by minimizing the dose-volume of the irradiated pericardium and heart.« less

Epinephrine and left atrial and left ventricular diastolic function decrease in normal subjects.

PubMed

Fuenmayor, Abdel J; Solórzano, Moisés I; Gómez, Luisangelly

2016-10-01

We assessed the effect of epinephrine over left atrial and left ventricular diastolic function in subjects without structural heart disease. Twenty-seven, 34.6±17.2year-old patients without structural heart disease were included. Intravenous epinephrine (50 to 100ng/kg/min) was infused. Left atrial and ventricular functions were evaluated by means of echocardiography before and during the epinephrine infusion. No complications were observed. Significant increases in heart rate and systolic blood pressure were recorded. Both left atrial (minimal and maximal) volumes increased but increase in the minimal volume was more pronounced, and the ejection fraction diminished. Left atrial expansion index decreased and the fraction of left ventricular inflow volume resulting from atrial contraction increased. Two patients displayed abnormal left ventricular diastolic function. During epinephrine infusion, E/A and e' decreased, and isovolumetric relaxation time increased. In this group of young adults without structural heart disease, epinephrine infusion was safe, did not produce any complications, and induced a small but significant decrease in left atrial function and left ventricular diastolic function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Measuring impedance in congestive heart failure: Current options and clinical applications

PubMed Central

Tang, W. H. Wilson; Tong, Wilson

2011-01-01

Measurement of impedance is becoming increasingly available in the clinical setting as a tool for assessing hemodynamics and volume status in patients with heart failure. The 2 major categories of impedance assessment are the band electrode method and the implanted device lead method. The exact sources of the impedance signal are complex and can be influenced by physiologic effects such as blood volume, fluid, and positioning. This article provides a critical review of our current understanding and promises of impedance measurements, the techniques that have evolved, as well as the evidence and limitations regarding their clinical applications in the setting of heart failure management. PMID:19249408

[Measurement of the electric field of the heart in a homogeneous volume conductor].

PubMed

Tsukerman, B M; Titomir, L I

1975-01-01

The paper describes a technique and some results of experimental measurements of electrical potentials generated by an isolated dog heart in homogeneous conductor, drawing equipotential maps of the field, and calculating the characteristics of the dipole equivalent generator of the heart. The form of potential distribution on a spherical surface around the heart and its ideal orthogonal vectorcardiograms are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massie, B.; Kramer, B.L.; Topic, N.

Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responsesmore » at rest were decreases in left and right ventricular end-diastolic volumes from 388 +/- 81 to 350 +/- 77 ml and from 52 +/- 26 to 43 +/- 20 volume units, respectively, and in their corresponding filling pressures, from 24 +/- 10 to 17 +/- 9 mm Hg and 10 +/- 5 to 6 +/- 5 mm Hg. Although stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 +/- 6% to 22+/- 5% and from 25 +/- 9% to 29 +/- 11%, respectively. During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. This, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.« less

Left ventricular volume analysis as a basic tool to describe cardiac function.

PubMed

Kerkhof, Peter L M; Kuznetsova, Tatiana; Ali, Rania; Handly, Neal

2018-03-01

The heart is often regarded as a compression pump. Therefore, determination of pressure and volume is essential for cardiac function analysis. Traditionally, ventricular performance was described in terms of the Starling curve, i.e., output related to input. This view is based on two variables (namely, stroke volume and end-diastolic volume), often studied in the isolated (i.e., denervated) heart, and has dominated the interpretation of cardiac mechanics over the last century. The ratio of the prevailing coordinates within that paradigm is termed ejection fraction (EF), which is the popular metric routinely used in the clinic. Here we present an insightful alternative approach while describing volume regulation by relating end-systolic volume (ESV) to end-diastolic volume. This route obviates the undesired use of metrics derived from differences or ratios, as employed in previous models. We illustrate basic principles concerning ventricular volume regulation by data obtained from intact animal experiments and collected in healthy humans. Special attention is given to sex-specific differences. The method can be applied to the dynamics of a single heart and to an ensemble of individuals. Group analysis allows for stratification regarding sex, age, medication, and additional clinically relevant covariates. A straightforward procedure derives the relationship between EF and ESV and describes myocardial oxygen consumption in terms of ESV. This representation enhances insight and reduces the impact of the metric EF, in favor of the end-systolic elastance concept advanced 4 decades ago.

Physical Activity and Mortality in Patients With Stable Coronary Heart Disease.

PubMed

Stewart, Ralph A H; Held, Claes; Hadziosmanovic, Nermin; Armstrong, Paul W; Cannon, Christopher P; Granger, Christopher B; Hagström, Emil; Hochman, Judith S; Koenig, Wolfgang; Lonn, Eva; Nicolau, José C; Steg, Philippe Gabriel; Vedin, Ola; Wallentin, Lars; White, Harvey D

2017-10-03

Recommendations for physical activity in patients with stable coronary heart disease (CHD) are based on modest evidence. The authors analyzed the association between self-reported exercise and mortality in patients with stable CHD. A total of 15,486 patients from 39 countries with stable CHD who participated in the STABILITY (Stabilization of Atherosclerotic Plaque by Initiation of Darapladib Therapy) study completed questions at baseline on hours spent each week taking mild, moderate, and vigorous exercise. Associations between the volume of habitual exercise in metabolic equivalents of task hours/week and adverse outcomes during a median follow-up of 3.7 years were evaluated. A graded decrease in mortality occurred with increased habitual exercise that was steeper at lower compared with higher exercise levels. Doubling exercise volume was associated with lower all-cause mortality (unadjusted hazard ratio [HR]: 0.82; 95% confidence interval [CI]: 0.79 to 0.85; adjusting for covariates, HR: 0.90; 95% CI: 0.87 to 0.93). These associations were similar for cardiovascular mortality (unadjusted HR: 0.83; 95% CI: 0.80 to 0.87; adjusted HR: 0.92; 95% CI: 0.88 to 0.96), but myocardial infarction and stroke were not associated with exercise volume after adjusting for covariates. The association between decrease in mortality and greater physical activity was stronger in the subgroup of patients at higher risk estimated by the ABC-CHD (Age, Biomarkers, Clinical-Coronary Heart Disease) risk score (p for interaction = 0.0007). In patients with stable CHD, more physical activity was associated with lower mortality. The largest benefits occurred between sedentary patient groups and between those with the highest mortality risk. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Determinants of kinetic energy of blood flow in the four-chambered heart in athletes and sedentary controls.

PubMed

Steding-Ehrenborg, K; Arvidsson, P M; Töger, J; Rydberg, M; Heiberg, E; Carlsson, M; Arheden, H

2016-01-01

The kinetic energy (KE) of intracardiac blood may play an important role in cardiac function. The aims of the present study were to 1) quantify and investigate the determinants of KE, 2) compare the KE expenditure of intracardiac blood between athletes and control subjects, and 3) quantify the amount of KE inside and outside the diastolic vortex. Fourteen athletes and fourteen volunteers underwent cardiac MRI, including four-dimensional phase-contrast sequences. KE was quantified in four chambers, and energy expenditure was calculated by determining the mean KE/cardiac index. Left ventricular (LV) mass was an independent predictor of diastolic LVKE (R(2) = 0.66, P < 0.001), whereas right ventricular (RV) end-diastolic volume was important for diastolic RVKE (R(2) = 0.76, P < 0.001). The mean KE/cardiac index did not differ between groups (control subjects: 0.53 ± 0.14 mJ·l(-1)·min·m(2) and athletes: 0.56 ± 0.21 mJ·l(-1)·min·m(2), P = 0.98). Mean LV diastolic vortex KE made up 70 ± 1% and 73 ± 2% of total LV diastolic KE in athletes and control subjects (P = 0.18). In conclusion, the characteristics of the LV as a pressure pump and the RV as a volume pump are demonstrated as an association between LVKE and LV mass and between RVKE and end-diastolic volume. This also suggests different filling mechanisms where the LV is dependent on diastolic suction, whereas the RV fills with a basal movement of the atrioventricular plane over "stationary" blood. Both groups had similar energy expenditure for intracardiac blood flow, indicating similar pumping efficiency, likely explained by the lower heart rate that cancels the higher KE per heart beat in athletes. The majority of LVKE is found within the LV diastolic vortex, in contrast to earlier findings. Copyright © 2016 the American Physiological Society.

Cardiac Function After Multimodal Breast Cancer Therapy Assessed With Functional Magnetic Resonance Imaging and Echocardiography Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heggemann, Felix, E-mail: felix.heggemann@umm.de; German Center for Cardiovascular Research, Mannheim; Grotz, Hanna

Purpose: Breast intensity modulated radiation therapy (IMRT) reduces high-dose heart volumes but increases low-dose volumes. We prospectively assessed heart changes after 3D conformal RT (3DCRT) and IMRT for left-sided breast cancer. Heart dose was analyzed individually, 3DCRT patients were moderately exposed, and IMRT was performed only in patients with unacceptably high heart doses upon 3DCRT planning. Methods and Materials: In 49 patients (38 patients received 3DCRT; 11 patients received IMRT; and 20 patients received neoadjuvant or adjuvant chemotherapy) magnetic resonance imaging (MRI) and echocardiography were performed before and at 6, 12, and 24 months after treatment. Results: Mean heart dose formore » IMRT was 12.9 ± 3.9 Gy versus 4.5 ± 2.4 Gy for 3DCRT. Heart volumes receiving >40 Gy were 2.6% (3DCRT) versus 1.3% (IMRT); doses were >50 Gy only with 3DCRT. Temporary ejection fraction (EF) decrease was observed on MRI after 6 months (63%-59%, P=.005) resolving at 24 months. Only 3 patients had pronounced largely transient changes of EF and left ventricular enddiastolic diameter (LVEDD). Mitral (M) and tricuspid (T) annular plane systolic excursion (MAPSE and TAPSE) were reduced over the whole cohort (still within normal range). After 24 months left ventricular remodeling index decreased in patients receiving chemotherapy (0.80 vs 0.70, P=.028). Neither wall motion abnormalities nor late enhancements were found. On echocardiography, in addition to EF findings that were similar to those on MRI, global strain was unchanged over the whole cohort at 24 months after a transient decrease at 6 and 12 months. Longitudinal strain decreased in the whole cohort after 24 months in some segments, whereas it increased in others. Conclusions: Until 24 months after risk-adapted modern multimodal adjuvant therapy, only subclinical cardiac changes were observed in both 3DCRT patients with inclusion of small to moderate amounts of heart volume in RT tangents and in the patients treated with IMRT and reduced high-dose heart exposure.« less

Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mory, Cyril, E-mail: cyril.mory@philips.com; Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes; Auvray, Vincent

2014-02-15

Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method,more » which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.« less

Coenzyme Q10 for the treatment of heart failure: a review of the literature

PubMed Central

DiNicolantonio, James J; Bhutani, Jaikrit; McCarty, Mark F; O'Keefe, James H

2015-01-01

Coenzyme Q10 (CoQ10) is an endogenously synthesised and diet-supplied lipid-soluble cofactor that functions in the mitochondrial inner membrane to transfer electrons from complexes I and II to complex III. In addition, its redox activity enables CoQ10 to act as a membrane antioxidant. In patients with congestive heart failure, myocardial CoQ10 content tends to decline as the degree of heart failure worsens. A number of controlled pilot trials with supplemental CoQ10 in heart failure found improvements in functional parameters such as ejection fraction, stroke volume and cardiac output, without side effects. Subsequent meta-analyses have confirmed these findings, although the magnitude of benefit tends to be less notable in patients with severe heart failure, or within the context of ACE inhibitor therapy. The multicentre randomised placebo-controlled Q-SYMBIO trial has assessed the impact of supplemental CoQ10 on hard endpoints in heart failure. A total of 420 patients received either CoQ10 (100 mg three times daily) or placebo and were followed for 2 years. Although short-term functional endpoints were not statistically different in the two groups, CoQ10 significantly reduced the primary long-term endpoint—a major adverse cardiovascular event—which was observed in 15% of the treated participants compared to 26% of those receiving placebo (HR=0.50, CI 0.32 to 0.80, p=0.003). Particularly in light of the excellent tolerance and affordability of this natural physiological compound, supplemental CoQ10 has emerged as an attractive option in the management of heart failure, and merits evaluation in additional large studies. PMID:26512330

Cardiovascular adaptations supporting human exercise-heat acclimation.

PubMed

Périard, Julien D; Travers, Gavin J S; Racinais, Sébastien; Sawka, Michael N

2016-04-01

This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses during exercise-heat acclimation. The cardiovascular system is well recognized as an important contributor to exercise-heat acclimation that acts to minimize physiological strain, reduce the risk of serious heat illness and better sustain exercise capacity. The upright posture adopted by humans during most physical activities and the large skin surface area contribute to the circulatory and blood pressure regulation challenge of simultaneously supporting skeletal muscle blood flow and dissipating heat via increased skin blood flow and sweat secretion during exercise-heat stress. Although it was traditionally held that cardiac output increased during exercise-heat stress to primarily support elevated skin blood flow requirements, recent evidence suggests that temperature-sensitive mechanisms may also mediate an elevation in skeletal muscle blood flow. The cardiovascular adaptations supporting this challenge include an increase in total body water, plasma volume expansion, better sustainment and/or elevation of stroke volume, reduction in heart rate, improvement in ventricular filling and myocardial efficiency, and enhanced skin blood flow and sweating responses. The magnitude of these adaptations is variable and dependent on several factors such as exercise intensity, duration of exposure, frequency and total number of exposures, as well as the environmental conditions (i.e. dry or humid heat) in which acclimation occurs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

[4D-CT-based plan target volume (PTV) definition compared with conventional PTV definition using general margin in radiotherapy for lung cancer].

PubMed

Ju, Xiao; Li, Minghui; Zhou, Zongmei; Zhang, Ke; Han, Wei; Fu, Guishan; Cao, Ying; Wang, Lyuhua

2014-01-01

To investigate the dosimetric benefit of 4D-CT in the planning target volume (PTV) definition process compared with conventional PTV definition using general margin in radiotherapy of lung cancer. A set of 4D-CT images and multiphase helical CT scans were obtained in 10 patients with lung cancer. The radiotherapeutic plans based on PTV determined by 4D-CT and in addition of general margin were performed, respectively. The 3D motion of the centroid of GTV and the 3D spatial motion vectors were calculated. The differences of the two kinds of PTVs, mean lung dose (MLD), V5,V10,V15,V20 of total lung, mean heart dose (MHD), V30 and V40 of heart, D99 and D95 were compared, and the correlation between them and the 3D spatial motion vector was analyzed. The PTV4D in eight patients were smaller than PTVconv, with a mean reduction of (13.0 ± 8.0)% (P = 0.018). In other two patients, whose respiration motion was great, PTV4D was larger than PTVconv. The mean 3D spatial motion vector of GTV centroid was (0.78 ± 0.72)cm. By using 4D-CT, the mean reduction of MLD was (8.6 ± 9.9)% (P = 0.037). V5, V10, V15, V20 of total lung were decreased averagely by (7.2 ± 10.5)%, (5.5 ± 8.9)%, (6.5 ± 8.4)% and (5.7 ± 7.4)%, respectively (P < 0.05 for all). There was a significant positive correlation between PTV4D/PTVconv and the 3D spatial motion vector of the GTV centroid (P = 0.008). A significant inverse correlation was found between D994D/D99conv and the 3D spatial motion vector of the GTV centroid (P = 0.002). D994D/D99conv, (MLDconv-MLD4D) /MLDconv, total lung (V5conv-V54D)/V5conv, total lung (V10conv-V104D)/V10conv, (MHDconv-MHD4D)/MHDconv, heart (V30conv-V304D)/V30conv were inversely correlated with PTV4D/PTVconv (P < 0.05 for all). 4D-CT can be used to evaluate the respiration motion of lung tumor accurately. The 4D-CT-based PTV definition and radiotherapeutic planing can reduce the volume of PTV in patients with small respiration motion, increase the intra-target dose, and decrease the dose of normal tissue sequentially. For patients with large respiration motion, especially those more than 1.5-2 cm, this method can avoid target miss, meanwhile, not increase the dose of normal tissue significantly.

Plasma Amino Acid Abnormalities in Chronic Heart Failure. Mechanisms, Potential Risks and Targets in Human Myocardium Metabolism

PubMed Central

Aquilani, Roberto; La Rovere, Maria Teresa; Corbellini, Daniela; Pasini, Evasio; Verri, Manuela; Barbieri, Annalisa; Condino, Anna Maria; Boschi, Federica

2017-01-01

The goal of this study was to measure arterial amino acid levels in patients with chronic heart failure (CHF), and relate them to left ventricular function and disease severity. Amino acids (AAs) play a crucial role for heart protein-energy metabolism. In heart failure, arterial AAs, which are the major determinant of AA uptake by the myocardium, are rarely measured. Forty-one subjects with clinically stable CHF (New York Heart Association (NYHA) class II to IV) were analyzed. After overnight fasting, blood samples from the radial artery were taken to measure AA concentrations. Calorie (KcalI), protein-, fat-, carbohydrate-intake, resting energy expenditure (REE), total daily energy expenditure (REE × 1.3), and cardiac right catheterization variables were all measured. Eight matched controls were compared for all measurements, with the exception of cardiac catheterization. Compared with controls, CHF patients had reduced arterial AA levels, of which both their number and reduced rates are related to Heart Failure (HF) severity. Arterial aspartic acid correlated with stroke volume index (r = 0.6263; p < 0.0001) and cardiac index (r = 0.4243; p = 0.0028). The value of arterial aspartic acid (µmol/L) multiplied by the cardiac index was associated with left ventricular ejection fraction (r = 0.3765; p = 0.0076). All NYHA groups had adequate protein intake (≥1.1 g/kg/day) and inadequate calorie intake (KcalI < REE × 1.3) was found only in class IV patients. This study showed that CHF patients had reduced arterial AA levels directly related to clinical disease severity and left ventricular dysfunction. PMID:29140312

Brain Dysplasia Associated with Ciliary Dysfunction In Infants with Congenital Heart Disease

PubMed Central

Panigrahy, Ashok; Lee, Vincent; Ceschin, Rafael; Zuccoli, Giulio; Beluk, Nancy; Khalifa, Omar; Votava-Smith, Jodie K; DeBrunner, Mark; Munoz, Ricardo; Domnina, Yuliya; Morell, Victor; Wearden, Peter; De Toledo, Joan Sanchez; Devine, William; Zahid, Maliha; Lo, Cecilia W.

2016-01-01

Objective To test for associations between abnormal respiratory ciliary motion (CM) and brain abnormalities in infants with congenital heart disease (CHD) Study design We recruited 35 infants with CHD preoperatively and performed nasal tissue biopsy to assess respiratory CM by videomicroscopy. Cranial ultrasound and brain magnetic resonance imaging were obtained pre- and/or post-operatively and systematically reviewed for brain abnormalities. Segmentation was used to quantitate cerebrospinal fluid and regional brain volumes. Perinatal and perioperative clinical variables were collected. Results A total of 10 (28.5%) patients with CHD had abnormal CM. Abnormal CM was not associated with brain injury, but was correlated with increased extra-axial CSF volume (p<0.001), delayed brain maturation (p<0.05), and a spectrum of subtle dysplasia including the hippocampus (p<0.0078) and olfactory bulb (p<0.034). Abnormal CM was associated with higher composite dysplasia score (p<0.001) and both were correlated with elevated pre-operative serum lactate (p <0.001). Conclusion Abnormal respiratory CM in infants with CHD is associated with a spectrum of brain dysplasia. These findings suggest that ciliary defects may play a role in brain dysplasia in patients with CHD and have the potential to prognosticate neurodevelopmental risks. PMID:27574995

Spaceflight Did Not Impair Cardiovascular Responses to Upright Posture in an Elderly Astronaut

NASA Technical Reports Server (NTRS)

Rossum, Alfred C.; Ziegler, Michael G.; Meck, Janice V.

2001-01-01

Some of the cardiovascular changes associated with spaceflight have similarities to those associated with aging. We studied the neuroendocrine and hemodynamic responses to upright posture in a 77 year old astronaut before and after spaceflight and compared them to those of a group of 20 younger (41 plus or minus 1 years) astronauts. While arterial pressure responses to standing were similar between the young and old astronauts, hemodynamic profiles were quite different. The elderly astronaut achieved adequate standing arterial pressure primarily by maintaining stroke volume and thus cardiac output. In spite of very high norepinephrine release, he had very little increase in heart rate or total peripheral resistance. This pattern persisted on all test occasions. These responses suggest high sympathetic responses, down-regulated adrenergic receptors and decreased venous compliance typical of aging. In contrast, younger astronauts did not maintain stroke volume or cardiac output with standing, but had significant increases in heart rate and resistance. These results suggest that this elderly subject had cardiovascular responses to standing that are expected in an aged person. These responses were not deleteriously affected by spaceflight. We suggest that healthy, fit elderly individuals are able to withstand the stresses of extreme environments and are not necessarily limited in their activities simply due to their chronological age.

Quantitative computed tomography of pulmonary emphysema and ventricular function in chronic obstructive pulmonary disease patients with pulmonary hypertension.

PubMed

Huang, Yu-Sen; Hsu, Hsao-Hsun; Chen, Jo-Yu; Tai, Mei-Hwa; Jaw, Fu-Shan; Chang, Yeun-Chung

2014-01-01

This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT). Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators. Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume (R(2) = 0.340, p = 0.023), RV stroke volume (R(2) = 0.406, p = 0.011), and RV cardiac output (R(2) = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed. The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.

Longitudinal analysis of quality of life, clinical, radiographic, echocardiographic, and laboratory variables in dogs with myxomatous mitral valve disease receiving pimobendan or benazepril: the QUEST study.

PubMed

Häggström, J; Boswood, A; O'Grady, M; Jöns, O; Smith, S; Swift, S; Borgarelli, M; Gavaghan, B; Kresken, J-G; Patteson, M; Åblad, B; Bussadori, C M; Glaus, T; Kovačević, A; Rapp, M; Santilli, R A; Tidholm, A; Eriksson, A; Belanger, M C; Deinert, M; Little, C J L; Kvart, C; French, A; Rønn-Landbo, M; Wess, G; Eggertsdottir, A; Lynne O'Sullivan, M; Schneider, M; Lombard, C W; Dukes-McEwan, J; Willis, R; Louvet, A; DiFruscia, R

2013-01-01

Myxomatous mitral valve disease (MMVD) is an important cause of morbidity and mortality in dogs. To compare, throughout the period of follow-up of dogs that had not yet reached the primary endpoint, the longitudinal effects of pimobendan versus benazepril hydrochloride treatment on quality-of-life (QoL) variables, concomitant congestive heart failure (CHF) treatment, and other outcome variables in dogs suffering from CHF secondary to MMVD. A total of 260 dogs in CHF because of MMVD. A prospective single-blinded study with dogs randomized to receive pimobendan (0.4-0.6 mg/kg/day) or benazepril hydrochloride (0.25-1.0 mg/kg/day). Differences in outcome variables and time to intensification of CHF treatment were compared. A total of 124 dogs were randomized to pimobendan and 128 to benazepril. No difference was found between groups in QoL variables during the trial. Time from inclusion to 1st intensification of CHF treatment was longer in the pimobendan group (pimobendan 98 days, IQR 30-276 days versus benazepril 59 days, IQR 11-121 days; P = .0005). Postinclusion, dogs in the pimobendan group had smaller heart size based on VHS score (P = .013) and left ventricular diastolic (P = .035) and systolic (P = .0044) dimensions, higher body temperature (P = .030), serum sodium (P = .0027), and total protein (P = .0003) concentrations, and packed cell volume (P = .030). Incidence of arrhythmias was similar in treatment groups. Pimobendan versus benazepril resulted in similar QoL during the study, but conferred increased time before intensification of CHF treatment. Pimobendan treatment resulted in smaller heart size, higher body temperature, and less retention of free water. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Exercise science: research to sustain and enhance performance

NASA Astrophysics Data System (ADS)

Wingo, Jonathan E.

2013-05-01

Cardiovascular adjustments accompanying exercise in high ambient temperatures are likely responsible for diminished aerobic capacity and performance in such conditions. These adjustments include a phenomenon known as cardiovascular drift in which heart rate rises and stroke volume declines progressively over time during constant-rate exercise. A variety of factors modulate the magnitude of cardiovascular drift, e.g., elevated core and skin temperatures, dehydration, and exercise intensity. Regardless of the mode of manipulation, decreases in stroke volume associated with cardiovascular drift result in directionally and proportionally similar decreases in maximal aerobic capacity. Maximal aerobic capacity is determined by maximal heart rate, maximal tissue oxygen extraction, and maximal stroke volume. Because maximal heart rate and maximal tissue oxygen extraction are unaffected during exercise in the heat, decreased stroke volume associated with cardiovascular drift likely persists during maximal efforts and explains the decrease in maximal aerobic capacity. Decreased maximal aerobic capacity results in a greater perceptual and physiological strain accompanying any given level of work. Therefore, sustaining and enhancing performance involves sophisticated monitoring of physiological strain combined with development of countermeasures that mitigate the magnitude of deleterious phenomena like cardiovascular drift.

[Review of wireless energy transmission system for total artificial heart].

PubMed

Zhang, Chi; Yang, Ming

2009-11-01

This paper sums up the fundamental structure of wireless energy transmission system for total artificial heart, and compares the key parameters and performance of some representative systems. After that, it is discussed that the future development trend of wireless energy transmission system for total artificial heart.

Moderate hypothermia technique for chronic implantation of a total artificial heart in calves.

PubMed

Karimov, Jamshid H; Grady, Patrick; Sinkewich, Martin; Sunagawa, Gengo; Dessoffy, Raymond; Byram, Nicole; Moazami, Nader; Fukamachi, Kiyotaka

2017-06-01

The benefit of whole-body hypothermia in preventing ischemic injury during cardiac surgical operations is well documented. However, application of hypothermia during in vivo total artificial heart implantation has not become widespread because of limited understanding of the proper techniques and restrictions implied by constitutional and physiological characteristics specific to each animal model. Similarly, the literature on hypothermic set-up in total artificial heart implantation has also been limited. Herein we present our experience using hypothermia in bovine models implanted with the Cleveland Clinic continuous-flow total artificial heart.

Determinants of incubation period: do reptilian embryos hatch after a fixed total number of heart beats?

PubMed

Du, Wei-Guo; Radder, Rajkumar S; Sun, Bo; Shine, Richard

2009-05-01

The eggs of birds typically hatch after a fixed (but lineage-specific) cumulative number of heart beats since the initiation of incubation. Is the same true for non-avian reptiles, despite wide intraspecific variation in incubation period generated by variable nest temperatures? Non-invasive monitoring of embryo heart beat rates in one turtle species (Pelodiscus sinensis) and two lizards (Bassiana duperreyi and Takydromus septentrionalis) show that the total number of heart beats during embryogenesis is relatively constant over a wide range of warm incubation conditions. However, incubation at low temperatures increases the total number of heart beats required to complete embryogenesis, because the embryo spends much of its time at temperatures that require maintenance functions but that do not allow embryonic growth or differentiation. Thus, cool-incubated embryos allocate additional metabolic effort to maintenance costs. Under warm conditions, total number of heart beats thus predicts incubation period in non-avian reptiles as well as in birds (the total number of heart beats are also similar); however, under the colder nest conditions often experienced by non-avian reptiles, maintenance costs add significantly to total embryonic metabolic expenditure.

Hemodynamic deterioration during extracorporeal membrane oxygenation weaning in a patient with a total artificial heart.

PubMed

Hosseinian, Leila; Levin, Matthew A; Fischer, Gregory W; Anyanwu, Anelechi C; Torregrossa, Gianluca; Evans, Adam S

2015-01-01

The Total Artificial Heart (Syncardia, Tucson, AZ) is approved for use as a bridge-to-transplant or destination therapy in patients who have irreversible end-stage biventricular heart failure. We present a unique case, in which the inferior vena cava compression by a total artificial heart was initially masked for days by the concurrent placement of an extracorporeal membrane oxygenation cannula. This is the case of a 33-year-old man admitted to our institution with recurrent episodes of ventricular tachycardia requiring emergent total artificial heart and venovenous extracorporeal membrane oxygenation placement. This interesting scenario highlights the importance for critical care physicians to have an understanding of exact anatomical localization of a total artificial heart, extracorporeal membrane oxygenation, and their potential interactions. In total artificial heart patients with hemodynamic compromise or reduced device filling, consideration should always be given to venous inflow compression, particularly in those with smaller body surface area. Transesophageal echocardiogram is a readily available diagnostic tool that must be considered standard of care, not only in the operating room but also in the ICU, when dealing with this complex subpopulation of cardiac patients.

Evaluation of General Toxicity, Anti-Oxidant Activity and Effects of Ficus Carica Leaves Extract on Ischemia/Reperfusion Injuries in Isolated Heart of Rat

PubMed Central

Allahyari, Saeideh; Delazar, Abbas; Najafi, Moslem

2014-01-01

Purpose: This study was aimed to evaluate general toxicity, anti-oxidant activity and effects of Ficus carica leaves extract on ischemia/reperfusion injuries. Methods: Antioxidant activity, total phenolic and flavonoid compounds of 70% methanolic extract of Ficus carica leaves were measured. The general toxicity test was carried out by brine shrimp lethality assay. Isolated hearts of male rats were mounted on a Langendorff apparatus and perfused with modified Krebs-Henseleit solution. In control group, the hearts were perfused with normal Krebs solution, however, treatment groups received enriched solution with the extract (0.04, 0.2 and 1 mg/ml) during stabilization and reperfusion (after 30 min global ischemia), respectively. Cardiac arrhythmias were analyzed and TTC method was used for infarct size determination. Results: The extract displayed antioxidant activity in the DPPH assay (RC50=0.06666 mg/ml). Total phenolic content was 12.29 mg GAE/100 g dry sample and the amount of flavonoids was calculated 40.729 mg/g. LD50 value by brine shrimp test was 0.158 mg/ml. The extract decreased number of VEBs, incidence and duration of Rev VF with clear reduction in infarct size and infarct volume (P<0.001). Conclusion: Ficus carica decreased ischemia/reperfusion-induced injuries. These protections are probably due to antioxidant capacity and the existence of flavonoid and phenolic compounds in the extract. PMID:25671192

Left atrial volume index in patients with heart failure and severely impaired left ventricular systolic function: the role of established echocardiographic parameters, circulating cystatin C and galectin-3.

PubMed

Zivlas, Christos; Triposkiadis, Filippos; Psarras, Stelios; Giamouzis, Gregory; Skoularigis, Ioannis; Chryssanthopoulos, Stavros; Kapelouzou, Alkistis; Ramcharitar, Steve; Barnes, Edward; Papasteriadis, Evangelos; Cokkinos, Dennis

2017-11-01

Backround: Left atrial (LA) enlargement plays an important role in the development of heart failure (HF) and is a robust prognostic factor. Fibrotic processes have also been advocated to evoke HF through finite signalling proteins. We examined the association of two such proteins, cystatin C (CysC) and galectin-3 (Gal-3), and other clinical, echocardiographic and biochemical parameters with LA volume index (LAVi) in patients with HF with severely impaired left ventricular ejection fraction (LVEF). Severe renal, liver, autoimmune disease and cancer were exclusion criteria. A total of 40 patients with HF (31 men, age 66.6 ± 1.7) with LVEF = 25.4 ± 0.9% were divided into two groups according to the mean LAVi (51.03 ± 2.9 ml/m 2 ) calculated by two-dimensional transthoracic echocardiography. Greater LAVi was positively associated with LV end-diastolic volume ( p = 0.017), LV end-systolic volume ( p = 0.025), mitral regurgitant volume (MRV) ( p = 0.001), right ventricular systolic pressure (RVSP) ( p < 0.001), restrictive diastolic filling pattern ( p = 0.003) and atrial fibrillation ( p = 0.005). Plasma CysC was positively correlated with LAVi ( R 2 = 0.135, p = 0.019) and log-transformed plasma Gal-3 ( R 2 = 0.109, p = 0.042) by simple linear regression analysis. Stepwise multiple linear regression analysis showed that only MRV ( t = 2.236, p = 0.032), CysC ( t = 2.467, p = 0.019) and RVSP ( t = 2.155, p = 0.038) were significant predictors of LAVi. Apart from known determinants of LAVi, circulating CysC and Gal-3 were associated with greater LA dilatation in patients with HF with reduced LVEF. Interestingly, the correlation between these two fibrotic proteins was positive.

Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, William; Filion, Edith; Roberge, David

2007-09-01

Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superiormore » for the IMRT plans for V{sub 95%} (IMRT, 100%; 3D, 96%; 2D, 98%) and V{sub 107%} (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V{sub 10Gy}, V{sub 15Gy}, and V{sub 20Gy}. The 3D plan was superior for V{sub 5Gy} and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V{sub 10Gy} and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose.« less

Management of hypertension and heart failure in patients with Addison's disease.

PubMed

Inder, Warrick J; Meyer, Caroline; Hunt, Penny J

2015-06-01

Addison's disease may be complicated by hypertension and less commonly by heart failure. We review the pathophysiology of the renin-angiotensin-aldosterone axis in Addison's disease and how this is altered in the setting of hypertension and heart failure. An essential first step in management in both conditions is optimizing glucocorticoid replacement and considering dose reduction if excessive. Following this, if a patient with Addison's disease remains hypertensive, the fludrocortisone dose should be reviewed and reduced if there are clinical and/or biochemical signs of mineralocorticoid excess. In the absence of such signs, where the renin is towards the upper end of the normal range or elevated, an angiotensin II (AII) receptor antagonist or angiotensin converting enzyme (ACE) inhibitor is the treatment of choice, and the fludrocortisone dose should remain unchanged. Dihydropyridine calcium channel blockers are clinically useful as second line agents, but diuretics should be avoided. In the setting of heart failure, there is an increase in total body sodium and water; therefore, it is appropriate to reduce and rarely consider ceasing the fludrocortisone. Loop diuretics may be used, but not aldosterone antagonists such as spironolactone or eplerenone. Standard treatment with ACE inhibitors, or as an alternative, AII receptor antagonists, are appropriate. Measurements of renin are no longer helpful in heart failure to determine the volume status but plasma levels of brain natriuretic peptide (BNP/proBNP) may help guide therapy. © 2014 John Wiley & Sons Ltd.

Anatomy of the python heart.

PubMed

Jensen, Bjarke; Nyengaard, Jens R; Pedersen, Michael; Wang, Tobias

2010-12-01

The hearts of all snakes and lizards consist of two atria and a single incompletely divided ventricle. In general, the squamate ventricle is subdivided into three chambers: cavum arteriosum (left), cavum venosum (medial) and cavum pulmonale (right). Although a similar division also applies to the heart of pythons, this family of snakes is unique amongst snakes in having intracardiac pressure separation. Here we provide a detailed anatomical description of the cardiac structures that confer this functional division. We measured the masses and volumes of the ventricular chambers, and we describe the gross morphology based on dissections of the heart from 13 ball pythons (Python regius) and one Burmese python (P. molurus). The cavum venosum is much reduced in pythons and constitutes approximately 10% of the cavum arteriosum. We suggest that shunts will always be less than 20%, while other studies conclude up to 50%. The high-pressure cavum arteriosum accounted for approximately 75% of the total ventricular mass, and was twice as dense as the low-pressure cavum pulmonale. The reptile ventricle has a core of spongious myocardium, but the three ventricular septa that separate the pulmonary and systemic chambers--the muscular ridge, the bulbuslamelle and the vertical septum--all had layers of compact myocardium. Pythons, however, have unique pads of connective tissue on the site of pressure separation. Because the hearts of varanid lizards, which also are endowed with pressure separation, share many of these morphological specializations, we propose that intraventricular compact myocardium is an indicator of high-pressure systems and possibly pressure separation.

Assessment by three-dimensional power Doppler ultrasound of cerebral blood flow perfusion in fetuses with congenital heart disease.

PubMed

Zeng, S; Zhou, J; Peng, Q; Tian, L; Xu, G; Zhao, Y; Wang, T; Zhou, Q

2015-06-01

To use three-dimensional (3D) power Doppler ultrasound to investigate cerebral blood flow perfusion in fetuses with congenital heart disease (CHD). The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) in the total intracranial volume and the main arterial territories (middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA)) were evaluated prospectively and compared in 112 fetuses with CHD and 112 normal fetuses using 3D power Doppler. Correlations between the 3D power Doppler indices and neurodevelopment scores at 12 months of age were assessed in a subset of the CHD group, and values were compared with those of controls. Compared with the controls, the VI, FI and VFI of the total intracranial volume and the three main arteries were significantly higher in fetuses with hypoplastic left heart syndrome and left-sided obstructive lesions (P < 0.001), and the 3D power Doppler values in the ACA territory were significantly higher in fetuses with transposition of the great arteries (P < 0.01). The largest proportional increase in the blood flow perfusion indices in the fetuses with CHD relative to controls was observed in the ACA territory (P < 0.05). Among 41 cases with CHD that underwent testing, the mean Psychomotor Development Index (PDI) and Mental Development Index (MDI) scores were significantly lower than in 94 of the controls that were tested (P < 0.001). Among these CHD cases, total intracranial FI was positively correlated with PDI (r = 0.342, P = 0.029) and MDI (r = 0.339, P = 0.030), and ACA-VI and ACA-VFI were positively correlated with PDI (r = 0.377 and 0.389, P = 0.015 and 0.012, respectively) but were not correlated with MDI (r = 0.243 and 0.203, P = 0.126 and 0.204, respectively). Cerebral blood flow perfusion was increased relative to controls in most fetuses with CHD and was associated with neurodevelopment scores at 12 months. Prenatal 3D power Doppler ultrasound might help to identify cases of brain vasodilatation earlier and inform parental counseling. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Cardiac index is associated with brain aging: the Framingham Heart Study.

PubMed

Jefferson, Angela L; Himali, Jayandra J; Beiser, Alexa S; Au, Rhoda; Massaro, Joseph M; Seshadri, Sudha; Gona, Philimon; Salton, Carol J; DeCarli, Charles; O'Donnell, Christopher J; Benjamin, Emelia J; Wolf, Philip A; Manning, Warren J

2010-08-17

Cardiac dysfunction is associated with neuroanatomic and neuropsychological changes in aging adults with prevalent cardiovascular disease, theoretically because systemic hypoperfusion disrupts cerebral perfusion, contributing to subclinical brain injury. We hypothesized that cardiac function, as measured by cardiac index, would be associated with preclinical brain magnetic resonance imaging (MRI) and neuropsychological markers of ischemia and Alzheimer disease in the community. Brain MRI, cardiac MRI, neuropsychological, and laboratory data were collected on 1504 Framingham Offspring Cohort participants free of clinical stroke, transient ischemic attack, or dementia (age, 61+/-9 years; 54% women). Neuropsychological and brain MRI variables were related to cardiac MRI-assessed cardiac index (cardiac output/body surface area). In multivariable-adjusted models, cardiac index was positively related to total brain volume (P=0.03) and information processing speed (P=0.02) and inversely related to lateral ventricular volume (P=0.048). When participants with clinically prevalent cardiovascular disease were excluded, the relation between cardiac index and total brain volume remained (P=0.02). Post hoc comparisons revealed that participants in the bottom cardiac index tertile (values <2.54) and middle cardiac index tertile (values between 2.54 and 2.92) had significantly lower brain volumes (P=0.04) than participants in the top cardiac index tertile (values >2.92). Although observational data cannot establish causality, our findings are consistent with the hypothesis that decreasing cardiac function, even at normal cardiac index levels, is associated with accelerated brain aging.

Cardiac index is associated with brain aging: The Framingham Heart Study

PubMed Central

Jefferson, Angela L.; Himali, Jayandra J.; Beiser, Alexa S.; Au, Rhoda; Massaro, Joseph M.; Seshadri, Sudha; Gona, Philimon; Salton, Carol J.; DeCarli, Charles; O’Donnell, Christopher J.; Benjamin, Emelia J.; Wolf, Philip A.; Manning, Warren J.

2010-01-01

Background Cardiac dysfunction is associated with neuroanatomic and neuropsychological changes in aging adults with prevalent cardiovascular disease (CVD), theoretically because systemic hypoperfusion disrupts cerebral perfusion, contributing to subclinical brain injury. We hypothesized that cardiac function, as measured by cardiac index, would be associated with pre-clinical brain magnetic resonance imaging (MRI) and neuropsychological markers of ischemia and Alzheimer’s disease in the community. Methods and Results Brain MRI, cardiac MRI, neuropsychological, and laboratory data were collected on 1504 Framingham Offspring Cohort participants free from clinical stroke, transient ischemic attack, or dementia (61±9 years; 54% women). Neuropsychological and brain MRI variables were related to cardiac MRI-assessed cardiac index (cardiac output/body surface area). In multivariable-adjusted models, cardiac index was positively related to total brain volume (P=0.03) and information processing speed (P=0.02) and inversely related to lateral ventricular volume (P=0.048). When participants with clinically prevalent CVD were excluded, the relation between cardiac index and total brain volume remained (P=0.02). Post-hoc comparisons revealed that participants in the bottom cardiac index tertile (values<2.54) and middle cardiac index tertile (values between 2.54 and 2.92) had significantly lower brain volumes (P=0.04) than participants in the top cardiac index tertile (values>2.92). Conclusions Although observational data cannot establish causality, our findings are consistent with the hypothesis that decreasing cardiac function, even at normal cardiac index levels, is associated with accelerated brain aging. PMID:20679552

Haemodynamic and energetic properties of stunned myocardium in rabbit hearts.

PubMed Central

Schipke, J. D.; Korbmacher, B.; Dorszewski, A.; Selcan, G.; Sunderdiek, U.; Arnold, G.

1996-01-01

OBJECTIVE--To amplify the description of myocardial stunning. DESIGN--Control versus 30 min after a 20 min no flow ischaemia. EXPERIMENTAL ANIMALS--15 isolated rabbit hearts perfused with erythrocyte suspension. MAIN OUTCOME MEASURES--Left ventricular systolic function in terms of aortic flow, peak systolic pressure (LVPmax), dP/dtmax, and the end systolic pressure-volume relation (ESPVR); early relaxation from dP/dtmin and rate of left ventricular pressure decay (tau). Passive properties: ventricular and myocardial stiffness. Coronary resistance from coronary blood flow and perfusion pressure. Total myocardial oxygen consumption (MVo2tot). Total mechanical energy via pressure-volume area (PVA). Contractile efficiency (Econ) and MVo2 of the unloaded contracting heart (MVo2unl). External mechanical efficiency (Eext) from stroke work and MVo2tot. RESULTS--Systolic variables in stunned myocardium were significantly decreased (mean (SD)): aortic flow: 38 (13) v 9 (11) ml/min; LVPmax: 112 (19) v 74 (18) mm Hg; dP/dtmax: 1475 (400) v 1075 (275) mm Hg/s. ESPVR was not significantly decreased, at 138 (73) v 125 (58) mm Hg/ml, but the volume axis intercept was shifted rightward: 0.30 (0.37) v 0.65 (0.25) ml. Likewise, early relaxation was impaired: dP/dtmin (-1275 (250) v -975 (250) mm Hg/s) and tau (37 (7) v 46 (10) ms). LVPed was significantly decreased at 19 (12) v 12 (7) mm Hg, and both the ventricular (end diastolic pressure-volume relation) and the myocardial stiffness (constant k) were increased by 75% and 31%, respectively. Coronary resistance increased non-significantly from 0.83 (0.31) to 1.04 (0.41) mm Hg/(ml/min/100 g). Decreases in PVA (570 (280) v 270 (200) mm Hg.ml/100 g), MVo2tot (40 (9) v 34 (8) microliters/beat/100 g), and MVo2unl (26 (9) v 22 (6) microliters/beat/100 g) did not reach significance, in contrast to significant decreases in Econ (31 (18) v 14 (7)%) and Eext (0.75 (0.29) v 0.18 (0.25) arbitrary units). CONCLUSIONS--Ventricular systolic function is decreased after brief episodes of ischaemia. The decrease in diastolic function probably amplifies the systolic deterioration during myocardial stunning. Passive diastolic properties are also changed, shown by increases in both ventricular and myocardial stiffness. The increase in coronary resistance indicates stunning at the vascular level which could limit oxygen supply. With maintained MVo2tot during stunning, external efficiency is decreased. Possible candidates for this metabolic stunning are inadequate excitation-contraction coupling and disturbed O2 utilisation by the contractile apparatus. Images PMID:8624873

Exercise physiology with a left ventricular assist device: Analysis of heart-pump interaction with a computational simulator.

PubMed

Fresiello, Libera; Rademakers, Frank; Claus, Piet; Ferrari, Gianfranco; Di Molfetta, Arianna; Meyns, Bart

2017-01-01

Patients with a Ventricular Assist Device (VAD) are hemodynamically stable but show an impaired exercise capacity. Aim of this work is to identify and to describe the limiting factors of exercise physiology with a VAD. We searched for data concerning exercise in heart failure condition and after VAD implantation from the literature. Data were analyzed by using a cardiorespiratory simulator that worked as a collector of inputs coming from different papers. As a preliminary step the simulator was used to reproduce the evolution of hemodynamics from rest to peak exercise (ergometer cycling) in heart failure condition. Results evidence an increase of cardiac output of +2.8 l/min and a heart rate increase to 67% of the expected value. Then, we simulated the effect of a continuous-flow VAD at both rest and exercise. Total cardiac output increases of +3.0 l/min (+0.9 l/min due to the VAD and +2.1 l/min to the native ventricle). Since the left ventricle works in a non-linear portion of the diastolic stiffness line, we observed a consistent increase of pulmonary capillary wedge pressure (from 14 to 20 mmHg) for a relatively small increase of end-diastolic volume (from 182 to 189 cm3). We finally increased VAD speed during exercise to the maximum possible value and we observed a reduction of wedge pressure (-4.5 mmHg), a slight improvement of cardiac output (8.0 l/min) and a complete unloading of the native ventricle. The VAD can assure a proper hemodynamics at rest, but provides an insufficient unloading of the left ventricle and does not prevent wedge pressure from rising during exercise. Neither the VAD provides major benefits during exercise in terms of total cardiac output, which increases to a similar extend to an unassisted heart failure condition. VAD speed modulation can contribute to better unload the ventricle but the maximal flow reachable with the current devices is below the cardiac output observed in a healthy heart.

Optimal hydration volume among high-risk patients with advanced congestive heart failure undergoing coronary angiography

PubMed Central

Wang, Kun; Chen, Ping Yan; Chen, Ji-Yan; Tan, Ning; Li, Li-Wen

2018-01-01

We investigated the relationship between weight-adjusted hydration volumes and the risk of developing contrast-induced acute kidney injury (CI-AKI) and worsening heart failure (WHF) and explored the relative safety of optimal hydration volumes in patients with advanced congestive heart failure (CHF) undergoing coronary angiography (CAG) or percutaneous coronary intervention. We included 551 patients with advanced CHF (New York Heart Association class > 2 or history of pulmonary edema) undergoing CAG (follow-up period 2.62 ± 0.9 years). There was a significant association between hydration volume-to-weight ratio (HV/W) (quintile Q1, Q2, Q3, Q4, and Q5) and the incidence of CI-AKI (3.7%, 14.6%, 14.3%, 21.1%, and 31.5%, respectively) and WHF (3.6%, 5.4%, 8.3%, 13.6%, and 19.1%, respectively) (all P-trend < 0.001). Receiver operating curve analysis indicated that HV/W = 15 mL/kg and the mean HV/W (60.87% sensitivity and 64.96% specificity) were fair discriminators for CI-AKI (C-statistic 0.696). HV/W >15 mL/kg independently predicted CI-AKI (adjusted odds ratio [OR] 2.33; P = 0.016) and WHF (adjusted OR 2.13; P = 0.018). Moreover, both CI-AKI and WHF were independently associated with increased long-term mortality. Thus, for high-risk patients with advanced CHF undergoing CAG, HV/W > 15 mL/kg might be associated with an increased risk of developing CI-AKI and WHF. The potential benefits of a personalized limitation of hydration volume need further evaluation. PMID:29805771

Evaluating Spatiotemporal Image Correlation Technology as a Tool for Training Nonexpert Sonographers to Perform Examinations of the Fetal Heart.

PubMed

Avnet, Hagai; Mazaaki, Eyal; Shen, Ori; Cohen, Sarah; Yagel, Simcha

2016-01-01

We aimed to evaluate the use of spatiotemporal image correlation (STIC) as a tool for training nonexpert examiners to perform screening examinations of the fetal heart by acquiring and examining STIC volumes according to a standardized questionnaire based on the 5 transverse planes of the fetal heart. We conducted a prospective study at 2 tertiary care centers. Two sonographers without formal training in fetal echocardiography received theoretical instruction on the 5 fetal echocardiographic transverse planes, as well as STIC technology. Only women with conditions allowing 4-dimensional STIC volume acquisitions (grayscale and Doppler) were included in the study. Acquired volumes were evaluated offline according to a standardized protocol that required the trainee to mark 30 specified structures on 5 required axial planes. Volumes were then reviewed by an expert examiner for quality of acquisition and correct identification of specified structures. Ninety-six of 112 pregnant women examined entered the study. Patients had singleton pregnancies between 20 and 32 weeks' gestation. After an initial learning curve of 20 examinations, trainees succeeded in identifying 97% to 98% of structures, with a highly significant degree of agreement with the expert's analysis (P < .001). A median of 2 STIC volumes for each examination was necessary for maximal structure identification. Acquisition quality scores were high (8.6-8.7 of a maximal score of 10) and were found to correlate with identification rates (P = .017). After an initial learning curve and under expert guidance, STIC is an excellent tool for trainees to master extended screening examinations of the fetal heart.

Self‐expanding stent effects on radiation dosimetry in esophageal cancer

PubMed Central

Francis, Samual R.; Wang, Brian; Williams, Greg V.; Cox, Kristen; Adler, Douglas G.; Shrieve, Dennis C.; Salter, Bill J.

2013-01-01

It is the purpose of this study to evaluate how self‐expanding stents (SESs) affect esophageal cancer radiation planning target volumes (PTVs) and dose delivered to surrounding organs at risk (OARs). Ten patients were evaluated, for whom a SES was placed before radiation. A computed tomography (CT) scan obtained before stent placement was fused to the post‐stent CT simulation scan. Three methods were used to represent pre‐stent PTVs: 1) image fusion (IF), 2) volume approximation (VA), and 3) diameter approximation (DA). PTVs and OARs were contoured per RTOG 1010 protocol using Eclipse Treatment Planning software. Post‐stent dosimetry for each patient was compared to approximated pre‐stent dosimetry. For each of the three pre‐stent approximations (IF, VA, and DA), the mean lung and liver doses and the estimated percentages of lung volumes receiving 5 Gy, 10 Gy, 20 Gy, and 30 Gy, and heart volumes receiving 40 Gy were significantly lower (p‐values <0.02) than those estimated in the post‐stent treatment plans. The lung V5, lung V10, and heart V40 constraints were achieved more often using our pre‐stent approximations. Esophageal SES placement increases the dose delivered to the lungs, heart, and liver. This may have clinical importance, especially when the dose‐volume constraints are near the recommended thresholds, as was the case for lung V5, lung V10, and heart V40. While stents have established benefits for treating patients with significant dysphagia, physicians considering stent placement and radiation therapy must realize the effects stents can have on the dosimetry. PACS number: 87.55.dk PMID:23835387

Self-expanding stent effects on radiation dosimetry in esophageal cancer.

PubMed

Francis, Samual R; Anker, Christopher J; Wang, Brian; Williams, Greg V; Cox, Kristen; Adler, Douglas G; Shrieve, Dennis C; Salter, Bill J

2013-07-08

It is the purpose of this study to evaluate how self-expanding stents (SESs) affect esophageal cancer radiation planning target volumes (PTVs) and dose delivered to surrounding organs at risk (OARs). Ten patients were evaluated, for whom a SES was placed before radiation. A computed tomography (CT) scan obtained before stent placement was fused to the post-stent CT simulation scan. Three methods were used to represent pre-stent PTVs: 1) image fusion (IF), 2) volume approximation (VA), and 3) diameter approximation (DA). PTVs and OARs were contoured per RTOG 1010 protocol using Eclipse Treatment Planning software. Post-stent dosimetry for each patient was compared to approximated pre-stent dosimetry. For each of the three pre-stent approximations (IF, VA, and DA), the mean lung and liver doses and the estimated percentages of lung volumes receiving 5 Gy, 10 Gy, 20 Gy, and 30 Gy, and heart volumes receiving 40 Gy were significantly lower (p-values < 0.02) than those estimated in the post-stent treatment plans. The lung V5, lung V10, and heart V40 constraints were achieved more often using our pre-stent approximations. Esophageal SES placement increases the dose delivered to the lungs, heart, and liver. This may have clinical importance, especially when the dose-volume constraints are near the recommended thresholds, as was the case for lung V5, lung V10, and heart V40. While stents have established benefits for treating patients with significant dysphagia, physicians considering stent placement and radiation therapy must realize the effects stents can have on the dosimetry.

Effects of depth and chest volume on cardiac function during breath-hold diving.

PubMed

Marabotti, Claudio; Scalzini, Alessandro; Cialoni, Danilo; Passera, Mirko; Ripoli, Andrea; L'Abbate, Antonio; Bedini, Remo

2009-07-01

Cardiac response to breath-hold diving in human beings is primarily characterized by the reduction of both heart rate and stroke volume. By underwater Doppler-echocardiography we observed a "restrictive/constrictive" left ventricular filling pattern compatible with the idea of chest squeeze and heart compression during diving. We hypothesized that underwater re-expansion of the chest would release heart constriction and normalize cardiac function. To this aim, 10 healthy male subjects (age 34.2 +/- 10.4) were evaluated by Doppler-echocardiography during breath-hold immersion at a depth of 10 m, before and after a single maximal inspiration from a SCUBA device. During the same session, all subjects were also studied at surface (full-body immersion) and at 5-m depth in order to better characterize the relationship of echo-Doppler pattern with depth. In comparison to surface immersion, 5-m deep diving was sufficient to reduce cardiac output (P = 0.042) and increase transmitral E-peak velocity (P < 0.001). These changes remained unaltered at a 10-m depth. Chest expansion at 10 m decreased left ventricular end-systolic volume (P = 0.024) and increased left ventricular stroke volume (P = 0.024). In addition, it decreased transmitral E-peak velocity (P = 0.012) and increased deceleration time of E-peak (P = 0.021). In conclusion the diving response, already evident during shallow diving (5 m) did not progress during deeper dives (10 m). The rapid improvement in systolic and diastolic function observed after lung volume expansion is congruous with the idea of a constrictive effect on the heart exerted by chest squeeze.

Noninvasive quantification of left ventricular mass by cardiac magnetic resonance imaging: Development of the method and experimental validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddahi, J.; Crues, J.; Berman, D.S.

1985-05-01

Determination of left ventricular myocardial (LV) mass may aid evaluation of hypertrophic cardiomyopathies as well as percent viable myocardium in ischemic heart disease. The validity of cardiac NMR for determination of LV mass was evaluated in 9 dogs using a superconducting magnet operating at 0.35 Tesla. In-vivo gated spin echo pulsing sequences were used obtaining 0.7 cm thick slices of the heart, spaced by 1 cm, in three orthogonal planes. After sacrifice, the nonbeating hearts were imaged in-situ without gating. On each NMR slice, the LV surface area was planimetered and multiplied by slice spacing (1) and myocardial specific gravitymore » (1.05) to obtain slice mass. For total LV mass, slice masses were added on coronal (Method (Meth) 1), transaxial (Meth 2), and sagittal (Meth 3) planes. Mass of the LV portions subject to partial volume effect were derived from an orthogonal plane. Excised LV weight ranged from 27 to 134 grams. The intra- and inter-observer agreement for planimetry of the NMR slices was high (r=.99 and r=.97, respectively). For in-situ imaging, r values of all methods were high (r=.99, .99, and .98); however, the slope and intercept of the regression line were closes to the line of identity with Meth 1 (y=0.94x+0.52). For in-vivo beating heart images, Meth 1 also had the best results (r=.99, y= 0.99x+8.3). Failure to correct for partial volume effect resulted in underestimation of in-situ and in-vivo LV masses as indicated by slope of <1 (r=,.98, y=0.77x+3.9; r=.98, y= 0.88x+0.98, respectively, Meth 1). Thus, cardiac NMR is a reproducible and accurate method for noninvasive determination of LV myocardial mass.« less

The effect of lifelong exercise dose on cardiovascular function during exercise

PubMed Central

Carrick-Ranson, Graeme; Hastings, Jeffrey L.; Bhella, Paul S.; Fujimoto, Naoki; Shibata, Shigeki; Palmer, M. Dean; Boyd, Kara; Livingston, Sheryl; Dijk, Erika

2014-01-01

An increased “dose” of endurance exercise training is associated with a greater maximal oxygen uptake (V̇o2max), a larger left ventricular (LV) mass, and improved heart rate and blood pressure control. However, the effect of lifelong exercise dose on metabolic and hemodynamic response during exercise has not been previously examined. We performed a cross-sectional study on 101 (69 men) seniors (60 yr and older) focusing on lifelong exercise frequency as an index of exercise dose. These included 27 who had performed ≤2 exercise sessions/wk (sedentary), 25 who performed 2–3 sessions/wk (casual), 24 who performed 4–5 sessions/wk (committed) and 25 who performed ≥6 sessions/wk plus regular competitions (Masters athletes) over at least the last 25 yr. Oxygen uptake and hemodynamics [cardiac output, stroke volume (SV)] were collected at rest, two levels of steady-state submaximal exercise, and maximal exercise. Doppler ultrasound measures of LV diastolic filling were assessed at rest and during LV loading (saline infusion) to simulate increased LV filling. Body composition, total blood volume, and heart rate recovery after maximal exercise were also examined. V̇o2max increased in a dose-dependent manner (P < 0.05). At maximal exercise, cardiac output and SV were largest in committed exercisers and Masters athletes (P < 0.05), while arteriovenous oxygen difference was greater in all trained groups (P < 0.05). At maximal exercise, effective arterial elastance, an index of ventricular-arterial coupling, was lower in committed exercisers and Masters athletes (P < 0.05). Doppler measures of LV filling were not enhanced at any condition, irrespective of lifelong exercise frequency. These data suggest that performing four or more weekly endurance exercise sessions over a lifetime results in significant gains in V̇o2max, SV, and heart rate regulation during exercise; however, improved SV regulation during exercise is not coupled with favorable effects on LV filling, even when the heart is fully loaded. PMID:24458750

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massie, B.; Kramer, B.L.; Topic, N.

Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responsesmore » at rest were decreases in left and right ventricular end-diastolic volumes from 388 + 81 to 350 + 77 ml (p < 0.01) and from 52 + 26 to 43 + 20 volume units (p < 0.01), respectively, and in their corresponding filling pressures, from 24 + 10 to 17 + 9 mm Hg and 10 + 5 to and + 5 mm Hg (both p < 0.01). Altough stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 + 6% to 22 + 5% and from 25 + 9% to 29 + 11%, respectively (both p < 0.01). During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. Thus, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.« less

SU-F-T-85: Energy Modulated Electron Postmastectomy Unreconstructed (PU) Chest Wall (CW) Irradiation Technique to Achieve Heart Sparing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, L; Ballangrud, A; Mechalakos, J

Purpose: For left-sided PU patients requiring CW and nodal irradiation, sometimes partial wide tangents (PWT) are not feasible due to abnormal chest wall contour or heart position close to the anterior chest wall or unusual wide excision scar. We developed an energy modulated electron chest wall irradiation technique that will achieve heart sparing. Methods: Ten left-sided PU patients were selected for this dosimetry study. If PWT were used, the amount of the ipsilateral lung would be ranged 3.4 to 4.4 cm, and the amount of heart would be ranged 1.3 to 3.8 cm. We used electron paired fields that matchedmore » on the skin to achieve dose conformity to the chest wall. The enface electron fields were designed at extended SSD from a single isocenter and gantry angle with different energy beams using different cutout. Lower energy was used in the central chest wall part and higher energy was used in the periphery of the chest wall. Bolus was used for the electron fields to ensure adequate skin dose coverage. The electron fields were matched to the photon supra-clavicle field in the superior region. Daily field junctions were used to feather the match lines between all the fields. Target volumes and normal tissues were drawn according to institutional protocols. Prescription dose was 2Gy per fraction for a total 50Gy. Dose calculations were done with Eclipse EMC-11031 for Electron and AAA-11031 for photons. Results: Six patients were planned using 6/9MeV, three using 9/12MeV and one 6/12MeV. Target volumes achieved adequate coverage. For heart, V30Gy, V20Gy and Mean Dose were 0.6%±0.6%, 2.7%±1.7%, and 3.0Gy±0.8Gy respectively. For ipsilateral lung, V50Gy, V20Gy, V10Gy and V5Gy were 0.9%±1.1%, 34.3%±5.1%, 51.6%±6.3% and 64.1%±7.5% respectively. Conclusion: For left-sided PU patients with unusual anatomy, energy modulated electron CW irradiation technique can achieve heart sparing with acceptable lung dose.« less

A protocol to study ex vivo mouse working heart at human-like heart rate.

PubMed

Feng, Han-Zhong; Jin, Jian-Ping

2018-01-01

Genetically modified mice are widely used as experimental models to study human heart function and diseases. However, the fast rate of normal mouse heart at 400-600bpm limits its capacity of assessing kinetic parameters that are important for the physiology and pathophysiology of human heart that beats at a much slower rate (75-180bpm). To extend the value of mouse models, we established a protocol to study ex vivo mouse working hearts at a human-like heart rate. In the presence of 300μM lidocaine to lower pacemaker and conductive activities and prevent arrhythmia, a stable rate of 120-130bpm at 37°C is achieved for ex vivo mouse working hearts. The negative effects of decreased heart rate on force-frequency dependence and lidocaine as a myocardial depressant on intracellular calcium can be compensated by using a higher but still physiological level of calcium (2.75mM) in the perfusion media. Multiple parameters were studied to compare the function at the human-like heart rate with that of ex vivo mouse working hearts at the standard rate of 480bpm. The results showed that the conditions for slower heart rate in the presence of 300μM lidocaine did not have depressing effect on left ventricular pressure development, systolic and diastolic velocities and stroke volume with maintained positive inotropic and lusitropic responses to β-adrenergic stimulation. Compared with that at 480bpm, the human-like heart rate increased ventricular filling and end diastolic volume with enhanced Frank-Starling responses. Coronary perfusion was increased from longer relaxation time and interval between beats whereas cardiac efficiency was significantly improved. Although the intrinsic differences between mouse and human heart remain, this methodology for ex vivo mouse hearts to work at human-like heart rate extends the value of using genetically modified mouse models to study cardiac function and human heart diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Blood-threshold CMR volume analysis of functional univentricular heart.

PubMed

Secchi, Francesco; Alì, Marco; Petrini, Marcello; Pluchinotta, Francesca Romana; Cozzi, Andrea; Carminati, Mario; Sardanelli, Francesco

2018-05-01

To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH). We evaluated retrospectively 44 FUH patients aged 25 ± 8 years (mean ± standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used. No significant difference was found between SV (median 57.7 ml; interquartile range 47.9-75.6) and aortic forward flow (57.4 ml; 48.9-80.4) (p = 0.123), with a high correlation (r = 0.789, p < 0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively. The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.

Two-dimensional echo-cardiographic estimation of left atrial volume and volume load in patients with congenital heart disease.

PubMed

Kawaguchi, A; Linde, L M; Imachi, T; Mizuno, H; Akutsu, H

1983-12-01

To estimate the left atrial volume (LAV) and pulmonary blood flow in patients with congenital heart disease (CHD), we employed two-dimensional echocardiography (TDE). The LAV was measured in dimensions other than those obtained in conventional M-mode echocardiography (M-mode echo). Mathematical and geometrical models for LAV calculation using the standard long-axis, short-axis and apical four-chamber planes were devised and found to be reliable in a preliminary study using porcine heart preparations, although length (10%), area (20%) and volume (38%) were significantly and consistently underestimated with echocardiography. Those models were then applied and correlated with angiocardiograms (ACG) in 25 consecutive patients with suspected CHD. In terms of the estimation of the absolute LAV, accuracy seemed commensurate with the number of the dimensions measured. The correlation between data obtained by TDE and ACG varied with changing hemodynamics such as cardiac cycle, absolute LAV and presence or absence of volume load. The left atrium was found to become spherical and progressively underestimated with TDE at ventricular endsystole, in larger LAV and with increased volume load. Since this tendency became less pronounced in measuring additional dimensions, reliable estimation of the absolute LAV and volume load was possible when 2 or 3 dimensions were measured. Among those calculation models depending on 2 or 3 dimensional measurements, there was only a small difference in terms of accuracy and predictability, although algorithm used varied from one model to another. This suggests that accurate cross-sectional area measurement is critically important for volume estimation rather than any particular algorithm involved. Cross-sectional area measurement by TDE integrated into a three dimensional equivalent allowed a reliable estimate of the LAV or volume load in a variety of hemodynamic situations where M-mode echo was not reliable.

Cardiovascular effects of anti-G suit inflation at 1 and 2 G.

PubMed

Montmerle, Stéphanie; Linnarsson, Dag

2005-06-01

We sought to determine to which pressure a full-coverage anti-G suit needs to be inflated in order to obtain the same stroke volume during a brief exposure to twice the normal gravity (2 G) as that at 1 G without anti-G suit inflation. Nine sitting subjects were studied at normal (1 G) and during 20 s of exposure to 2 G. They wore anti-G suits, which were inflated at both G-levels to the following target pressures: 0, 70, 140 and 210 mmHg. Stroke volume was computed from cardiac output, which was measured by rebreathing. Heart rate and mean arterial pressure at heart level were recorded. Inflation to 70 mmHg compensated for the decrease in stroke volume and cardiac output caused by hypergravity. Mean arterial pressure at heart level was comparable at 1 G and at 2 G and increased gradually and similarly with inflation (P<0.001) at both gravity levels. Thus, anti-G suits act by increasing both preload and afterload but the two effects counteract each other in terms of cardiac output, so that cardiac output at 2 G is maintained at its 1 G level. This effect is reached already at 70 mmHg of inflation. Greater inflation pressure further increases mean arterial pressure at heart level and compensates for the increased difference in hydrostatic pressure between heart and head in moderate hypergravity.

The efficacy of tolvaptan in the perioperative management of chronic kidney disease patients undergoing open-heart surgery.

PubMed

Yamada, Mitsutomo; Nishi, Hiroyuki; Sekiya, Naosumi; Horikawa, Kohei; Takahashi, Toshiki; Sawa, Yoshiki

2017-04-01

The perioperative management of chronic kidney disease (CKD) patients undergoing open-heart surgery is challenging. In this study, we evaluated the effects of tolvaptan in CKD patients after open-heart surgery. Between 2010 to 2015, 731 patients underwent open-heart surgery in our hospital. We consecutively selected 71 patients with stage IIIa-IV CKD and divided them into two groups. Those who received tolvaptan postoperatively were defined as the "Tolvaptan group" (n = 25) and those who did not were defined as the "Non-tolvaptan group" (n = 46). We compared the urine volume of postoperative days (POD) 1 and 2, the number of days to return to preoperative body weight (BW), and the change in the postoperative estimated glomerular filtration rate (eGFR). In the tolvaptan group, the urine volume was significantly larger (P = .04) and the duration to preoperative BW tended to be shorter. Overall, the postoperative change in the eGFR tended to be better in the tolvaptan group (P = .008). In particular, we found a significantly better trend in CKD stage IV (P = .04) patients and in the patients, whose cardiopulmonary bypass (CPB) time was longer than 120 min (P = .03). Tolvaptan can safely be used for CKD patients undergoing open-heart surgery and can provide a feasible urine volume without leading to a deterioration of their renal function.

[Total artificial heart].

PubMed

Antretter, H; Dumfarth, J; Höfer, D

2015-09-01

To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

Effect of lung volume reduction surgery on resting pulmonary hemodynamics in severe emphysema.

PubMed

Criner, Gerard J; Scharf, Steven M; Falk, Jeremy A; Gaughan, John P; Sternberg, Alice L; Patel, Namrata B; Fessler, Henry E; Minai, Omar A; Fishman, Alfred P

2007-08-01

To determine the effect of medical treatment versus lung volume reduction surgery (LVRS) on pulmonary hemodynamics. Three clinical centers of the National Emphysema Treatment Trial (NETT) screened patients for additional inclusion into a cardiovascular (CV) substudy. Demographics were determined, and lung function testing, six-minute-walk distance, and maximum cardiopulmonary exercise testing were done at baseline and 6 months after medical therapy or LVRS. CV substudy patients underwent right heart catheterization at rest prerandomization (baseline) and 6 months after treatment. A total of 110 of the 163 patients evaluated for the CV substudy were randomized in NETT (53 were ineligible), 54 to medical treatment and 56 to LVRS. Fifty-five of these patients had both baseline and repeat right heart catheterization 6 months postrandomization. Baseline demographics and lung function data revealed CV substudy patients to be similar to the remaining 1,163 randomized NETT patients in terms of age, sex, FEV(1), residual volume, diffusion capacity of carbon monoxide, Pa(O(2)), Pa(CO(2)), and six-minute-walk distance. CV substudy patients had moderate pulmonary hypertension at rest (Ppa, 24.8 +/- 4.9 mm Hg); baseline hemodynamic measurements were similar across groups. Changes from baseline pressures to 6 months post-treatment were similar across treatment groups, except for a smaller change in pulmonary capillary wedge pressure at end-expiration post-LVRS compared with medical treatment (-1.8 vs. 3.5 mm Hg, p = 0.04). In comparison to medical therapy, LVRS was not associated with an increase in pulmonary artery pressures.

Age at menarche, total mortality and mortality from ischaemic heart disease and stroke: the Adventist Health Study, 1976–88

PubMed Central

Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E

2009-01-01

Background Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. Methods A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. Results An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16–18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3–6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2–10.6)] and stroke [8.6% (95% CI 1.6–15.1)] mortality. Conclusions The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality. PMID:19188208

Age at menarche, total mortality and mortality from ischaemic heart disease and stroke: the Adventist Health Study, 1976-88.

PubMed

Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E

2009-02-01

Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16-18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3-6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2-10.6)] and stroke [8.6% (95% CI 1.6-15.1)] mortality. The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality.

Pulmonary hypertension due to left heart disease: diagnostic and prognostic value of CT in chronic systolic heart failure.

PubMed

Colin, Geoffrey C; Gerber, Bernhard L; de Meester de Ravenstein, Christophe; Byl, David; Dietz, Anna; Kamga, Michele; Pasquet, Agnes; Vancraeynest, David; Vanoverschelde, Jean-Louis; D'Hondt, Anne-Marie; Ghaye, Benoit; Pouleur, Anne-Catherine

2018-05-14

To evaluate the ability of chest computed tomography (CT) to predict pulmonary hypertension (PH) and outcome in chronic heart failure with reduced ejection fraction (HFrEF). We reviewed 119 consecutive patients with HFrEF by CT, transthoracic echocardiography (TTE) and right heart catheterization (RHC). CT-derived pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio), left atrial, right atrial, right ventricular (RV) and left ventricular volumes were correlated with RHC mean pulmonary arterial pressure (mPAP) . Diagnostic accuracy to predict PH and ability to predict primary composite endpoint of all-cause mortality and HF events were evaluated. RV volume was significantly higher in 81 patients with PH compared to 38 patients without PH (133 ml/m 2 vs. 79 ml/m 2 , p < 0.001) and was moderately correlated with mPAP (r=0.55, p < 0.001). Also, RV volume had higher ability to predict PH (area under the curve: 0.88) than PA diameter (0.79), PA:A ratio (0.76) by CT and tricuspid regurgitation gradient (0.83) and RV basal diameter by TTE (0.84, all p < 0.001). During the follow-up period (median: 3.4 years), 51 patients (43%) had HF events or died. After correction for important clinical, TTE and RHC parameters, RV volume (adjusted hazard ratio [HR]: 1.71, 95% CI 1.31-2.23, p < 0.001) and PA diameter (HR: 1.61, 95% CI 1.18-2.22, p = 0.003) were independent predictors of the primary endpoint. In patients with HFrEF, measurement of RV volume and PA diameter on ungated CT are non-invasive markers of PH and may help to predict the patient outcome. • Right ventricular (RV) volume measured by chest CT has good ability to identify pulmonary hypertension (PH) in patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF). • The accuracy of pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio) to predict PH was similar to previous studies, however, with lower cut-offs (28.1 mm and 0.92, respectively). • Chest CT-derived PA diameter and RV volume independently predict all-cause mortality and HF events and improve outcome prediction in patients with advanced HFrEF.

Hemodynamic Correlates of Abnormal Aortic Root Dimension in an Adult Population: The Strong Heart Study.

PubMed

de Simone, Giovanni; Roman, Mary J; De Marco, Marina; Bella, Jonathan N; Izzo, Raffaele; Lee, Elisa T; Devereux, Richard B

2015-09-28

We evaluated the relationship of aortic root dimension (ARD) with flow output and both peripheral and central blood pressure, using multivariable equations predicting ideal sex-specific ARD at a given age and body height. We measured echocardiographic diastolic ARD at the sinuses of Valsalva in 3160 adults (aged 42±16 years, 61% women) from the fourth examination of the Strong Heart Study who were free of prevalent coronary heart disease, and we compared measured data with the theoretical predicted value to calculate a z score. Central blood pressure was estimated by applanation tonometry of the radial artery in 2319 participants. ARD z scores were divided into tertiles representing small, normal, and large ARD. Participants with large ARD exhibited greater prevalence of central obesity and higher levels of inflammatory markers and lipids (0.05

Ongoing right ventricular hemodynamics in heart failure: clinical value of measurements derived from an implantable monitoring system.

PubMed

Adamson, Philip B; Magalski, Anthony; Braunschweig, Frieder; Böhm, Michael; Reynolds, Dwight; Steinhaus, David; Luby, Allyson; Linde, Cecilia; Ryden, Lars; Cremers, Bodo; Takle, Teri; Bennett, Tom

2003-02-19

This study examined the characteristics of continuously measured right ventricular (RV) hemodynamic information derived from an implantable hemodynamic monitor (IHM) in heart failure patients. Hemodynamic monitoring might improve the day-to-day management of patients with chronic heart failure (CHF). Little is known about the characteristics of long-term hemodynamic information in patients with CHF or how such information relates to meaningful clinical events. Thirty-two patients with CHF received a permanent RV IHM system similar to a single-lead pacemaker. Right ventricular systolic and diastolic pressures, heart rate, and pressure derivatives were continuously measured for nine months without using the data for clinical decision-making or management of patients. Data were then made available to clinical providers, and the patients were followed up for 17 months. Pressure characteristics during optimal volume, clinically determined volume-overload exacerbations, and volume depletion events were examined. The effect of IHM on hospitalizations was examined using the patients' historical controls. Long-term RV pressure measurements had either marked variability or minimal time-related changes. During 36 volume-overload events, RV systolic pressures increased by 25 +/- 4% (p < 0.05) and heart rate increased by 11 +/- 2% (p < 0.05). Pressure increases occurred in 9 of 12 events 4 +/- 2 days before the exacerbations requiring hospitalization. Hospitalizations before using IHM data for clinical management averaged 1.08 per patient year and decreased to 0.47 per patient-year (57% reduction, p < 0.01) after hemodynamic data were used. Long-term ambulatory pressure measurements from an IHM may be helpful in guiding day-to-day clinical management, with a potentially favorable impact on CHF hospitalizations.

Correlation of primary middle and distal esophageal cancers motion with surrounding tissues using four-dimensional computed tomography.

PubMed

Wang, Wei; Li, Jianbin; Zhang, Yingjie; Shao, Qian; Xu, Min; Guo, Bing; Shang, Dongping

2016-01-01

To investigate the correlation of gross tumor volume (GTV) motion with the structure of interest (SOI) motion and volume variation for middle and distal esophageal cancers using four-dimensional computed tomography (4DCT). Thirty-three patients with middle or distal esophageal carcinoma underwent 4DCT simulation scan during free breathing. All image sets were registered with 0% phase, and the GTV, apex of diaphragm, lung, and heart were delineated on each phase of the 4DCT data. The position of GTV and SOI was identified in all 4DCT phases, and the volume of lung and heart was also achieved. The phase relationship between the GTV and SOI was estimated through Pearson's correlation test. The mean peak-to-peak displacement of all primary tumors in the lateral (LR), anteroposterior (AP), and superoinferior (SI) directions was 0.13 cm, 0.20 cm, and 0.30 cm, respectively. The SI peak-to-peak motion of the GTV was defined as the greatest magnitude of motion. The displacement of GTV correlated well with heart in three dimensions and significantly associated with bilateral lung in LR and SI directions. A significant correlation was found between the GTV and apex of the diaphragm in SI direction (r left=0.918 and r right=0.928). A significant inverse correlation was found between GTV motion and varying lung volume, but the correlation was not significant with heart (r LR=-0.530, r AP=-0.531, and r SI=-0.588) during respiratory cycle. For middle and distal esophageal cancers, GTV should expand asymmetric internal margins. The primary tumor motion has quite good correlation with diaphragm, heart, and lung.

Three-dimensional histology: tools and application to quantitative assessment of cell-type distribution in rabbit heart

PubMed Central

Burton, Rebecca A.B.; Lee, Peter; Casero, Ramón; Garny, Alan; Siedlecka, Urszula; Schneider, Jürgen E.; Kohl, Peter; Grau, Vicente

2014-01-01

Aims Cardiac histo-anatomical organization is a major determinant of function. Changes in tissue structure are a relevant factor in normal and disease development, and form targets of therapeutic interventions. The purpose of this study was to test tools aimed to allow quantitative assessment of cell-type distribution from large histology and magnetic resonance imaging- (MRI) based datasets. Methods and results Rabbit heart fixation during cardioplegic arrest and MRI were followed by serial sectioning of the whole heart and light-microscopic imaging of trichrome-stained tissue. Segmentation techniques developed specifically for this project were applied to segment myocardial tissue in the MRI and histology datasets. In addition, histology slices were segmented into myocytes, connective tissue, and undefined. A bounding surface, containing the whole heart, was established for both MRI and histology. Volumes contained in the bounding surface (called ‘anatomical volume’), as well as that identified as containing any of the above tissue categories (called ‘morphological volume’), were calculated. The anatomical volume was 7.8 cm3 in MRI, and this reduced to 4.9 cm3 after histological processing, representing an ‘anatomical’ shrinkage by 37.2%. The morphological volume decreased by 48% between MRI and histology, highlighting the presence of additional tissue-level shrinkage (e.g. an increase in interstitial cleft space). The ratio of pixels classified as containing myocytes to pixels identified as non-myocytes was roughly 6:1 (61.6 vs. 9.8%; the remaining fraction of 28.6% was ‘undefined’). Conclusion Qualitative and quantitative differentiation between myocytes and connective tissue, using state-of-the-art high-resolution serial histology techniques, allows identification of cell-type distribution in whole-heart datasets. Comparison with MRI illustrates a pronounced reduction in anatomical and morphological volumes during histology processing. PMID:25362175

Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)

NASA Technical Reports Server (NTRS)

Pantalos, George M.; Bennett, Thomas E.; Sharp, M. Keith; Woodruff, Stewart; Oleary, Sean; Gillars, Kevin; Lemon, Mark; Sojka, Jan

1995-01-01

The investigation of cardiovascular adaptation to space flight has seen substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented an initial increase, followed by a progressive reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been identified. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a Get Away Special (GAS) payload within the next year.

Smaller size of high metabolic rate organs explains lower resting energy expenditure in Asian-Indian Than Chinese men.

PubMed

Song, L L T; Venkataraman, K; Gluckman, P; Chong, Y S; Chee, M-W L; Khoo, C M; Leow, M-Ks; Lee, Y S; Tai, E S; Khoo, E Y H

2016-04-01

In Singapore, the obesity prevalence is disproportionately higher in the Asian-Indians and Malays than the Chinese. Lower resting energy expenditure (REE) may be a contributory factor. We explored the association between ethnicity and REE in Chinese, Asian-Indian and Malay men living in Singapore and determined the influence of body composition, mass/volume of high metabolic rate organs, represented by brain volume and trunk fat-free mass (FFM), and physical activity on ethnic differences. Two hundred and forty-four men from Singapore (n=100 Chinese, 70 Asian-Indians and 74 Malays), aged 21-40 years and body mass index of 18.5-30.0 kg m(-2), were recruited in this cross-sectional study. REE was assessed by indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Brain volume was measured by magnetic resonance imaging. Physical activity was assessed by the Singapore Prospective Study Program Physical Activity Questionnaire. REE was significantly lower in Asian-Indians compared with that in Chinese after adjusting for body weight. FFM (total, trunk and limb) and total fat mass were important predictors of REE across all ethnic groups. Brain volume was positively associated with REE only in Malays. Moderate and vigorous physical activity was positively associated with REE only in Asian-Indians and Malays. The difference in REE between Asian-Indians and Chinese was attenuated but remained statistically significant after adjustment for total FFM (59±20 kcal per day), fat mass (67±20 kcal per day) and brain volume (54±22 kcal per day). The association between REE and ethnicity was no longer statistically significant after total FFM was replaced by trunk FFM (which includes heart, liver, kidney and spleen) but not when it was replaced by limb FFM (skeletal muscle). We have demonstrated a lower REE in Asian-Indians compared with Chinese who may contribute to the higher rates of obesity in the former. This difference could be accounted for by differences in metabolically active organs.

Gastrointestinal hemodynamics during compensation for hemorrhage and measurement of Pmcf.

PubMed

Rothe, C F; Maass-Moreno, R

1994-03-01

To quantify the degree of autonomic reflex control of the gastrointestinal vasculature, we studied the responses to a 10-ml/kg hemorrhage or transfusion and autonomic blockade in fentanyl- and pentobarbital-anesthetized dogs. The active total blood volume was estimated by indocyanine green dilution. Transfusion and hemorrhage did not significantly change gastrointestinal vascular compliance [1.82 +/- 0.68 (SD) ml/mmHg], but autonomic blockade with hexamethonium and atropine increased it by 0.57 +/- 0.37 ml/mmHg. Neither hemorrhage nor autonomic blockade significantly changed gastrointestinal vascular resistance from its control value of 10.8 +/- 4 mmHg.ml-1.min.kg body wt, but transfusion reduced it by 3.0 +/- 1.2 mmHg.ml-1.min.kg body wt. The ratio of gastrointestinal vascular resistance to total peripheral resistance was not significantly changed, however. We conclude that vascular compliance and resistance of the gastrointestinal bed are minimally influenced by the autonomic nervous system under the conditions studied. Portal pressure and flow measurements (transit-time ultrasound) during the above maneuvers were also combined with estimations of mean circulatory filling pressure (Pmcf) to test the hypothesis that, when the heart is stopped to measure Pmcf, portal pressure equals central venous pressure (Pcv) and hence that portal flow is zero. Seven seconds after the heart was stopped, portal venous pressure (Ppv) remained 0.83 +/- 0.78 mmHg higher than Pcv and portal flow decreased to only 25% of its control value. However, gastrointestinal compliance times (Ppv-Pcv), an estimate of the extra distending volume, was only 0.07 +/- 0.07 ml/kg body wt. Thus we conclude that the error in estimating Pmcf, given this (Ppv-Pcv) difference, is physiologically insignificant.

The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

NASA Technical Reports Server (NTRS)

Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

1994-01-01

Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

Respiration Induced Heart Motion and Indications of Gated Delivery for Left-Sided Breast Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, X. Sharon, E-mail: xiangrong.qi@ucdenver.edu; Hu, Angela; Wang Kai

Purpose: To investigate respiration-induced heart motion for left-sided breast irradiation using a four-dimensional computed tomography (4DCT) technique and to determine novel indications to assess heart motion and identify breast patients who may benefit from a gated treatment. Methods and Materials: Images of 4DCT acquired during free breathing for 20 left-sided breast cancer patients, who underwent whole breast irradiation with or without regional nodal irradiation, were analyzed retrospectively. Dose distributions were reconstructed in the phases of 0%, 20%, and 50%. The intrafractional heart displacement was measured in three selected transverse CT slices using D{sub LAD} (the distance from left ascending aortamore » to a fixed line [connecting middle point of sternum and the body] drawn on each slice) and maximum heart depth (MHD, the distance of the forefront of the heart to the line). Linear regression analysis was used to correlate these indices with mean heart dose and heart dose volume at different breathing phases. Results: Respiration-induced heart displacement resulted in observable variations in dose delivered to the heart. During a normal free-breathing cycle, heart-induced motion D{sub LAD} and MHD changed up to 9 and 11 mm respectively, resulting in up to 38% and 39% increases of mean doses and V{sub 25.2} for the heart. MHD and D{sub LAD} were positively correlated with mean heart dose and heart dose volume. Respiratory-adapted gated treatment may better spare heart and ipsilateral-lung compared with the conventional non-gated plan in a subset of patients with large D{sub LAD} or MHD variations. Conclusion: Proposed indices offer novel assessment of heart displacement based on 4DCT images. MHD and D{sub LAD} can be used independently or jointly as selection criteria for respiratory gating procedure before treatment planning. Patients with great intrafractional MHD variations or tumor(s) close to the diaphragm may particularly benefit from the gated treatment.« less

Emerging hemodynamic signatures of the right heart (Third International Right Heart Failure Summit, part 2).

PubMed

Maron, Bradley A

2014-12-01

Despite the importance of preserved right ventricular structure and function with respect to outcome across the spectrum of lung, cardiac, and pulmonary vascular diseases, only recently have organized efforts developed to consider the pulmonary vascular-right ventricular apparatus as a specific unit within the larger context of cardiopulmonary pathophysiology. The Third International Right Heart Failure Summit (Boston, MA) was a multidisciplinary event dedicated to promoting a dialogue about the scientific and clinical basis of right heart disease. The current review provides a synopsis of key discussions presented during the section of the summit titled "Emerging Hemodynamic Signatures of the Right Heart." Specifically, topics emphasized in this element of the symposium included (1) the effects of pulmonary vascular dysfunction at rest or provoked by exercise on the right ventricular pressure-volume relationship, (2) the role of pressure-volume loop analysis as a method to characterize right ventricular inefficiency and predict right heart failure, and (3) the importance of a systems biology approach to identifying novel factors that contribute to pathophenotypes associated with pulmonary arterial hypertension and/or right ventricular dysfunction. Collectively, these concepts frame a forward-thinking paradigm shift in the approach to right heart disease by emphasizing factors that regulate the transition from adaptive to maladaptive right ventricular-pulmonary vascular (patho)physiology.

Hemodynamic and neurohormonal responses to extreme orthostatic stress in physically fit young adults

NASA Astrophysics Data System (ADS)

Grasser, E. K.; Goswami, N.; Rössler, A.; Vrecko, K.; Hinghofer-Szalkay, H.

2009-04-01

Blood pressure stability may be jeopardized in astronauts experiencing orthostatic stress. There is disagreement about cardiovascular and endocrine stress responses that emerge when a critical (presyncopal) state is reached. We studied hemodynamic and neurohormonal changes as induced by an orthostatic stress paradigm (head-up tilt combined with lower body negative pressure) that leads to a syncopal endpoint. From supine control to presyncope, heart rate increased by 78% and thoracic impedance by 12%. There was a 49% fall in stroke volume index, 19% in mean arterial blood pressure, 14% in total peripheral resistance index and 11% in plasma volume. Plasma norepinephrine rose by 107, epinephrine by 491, plasma renin activity by 167, and cortisol by 25%. Hemodynamic and hormonal changes of clearly different magnitude emerge in presyncope as compared to supine rest. Additional studies are warranted to reveal the exact time course of orthostatic changes up to syncopal levels.

Effects of Vildagliptin on Ventricular Function in Patients With Type 2 Diabetes Mellitus and Heart Failure: A Randomized Placebo-Controlled Trial.

PubMed

McMurray, John J V; Ponikowski, Piotr; Bolli, Geremia B; Lukashevich, Valentina; Kozlovski, Plamen; Kothny, Wolfgang; Lewsey, James D; Krum, Henry

2018-01-01

This study sought to examine the safety of the dipeptidyl peptidase-4 inhibitor, vildagliptin, in patients with heart failure and reduced ejection fraction. Many patients with type 2 diabetes mellitus have heart failure and it is important to know about the safety of new treatments for diabetes in these individuals. Patients 18 to 85 years of age with type 2 diabetes and heart failure (New York Heart Association functional class I to III and left ventricular ejection fraction [LVEF] <0.40) were randomized to 52 weeks treatment with vildagliptin 50 mg twice daily (50 mg once daily if treated with a sulfonylurea) or matching placebo. The primary endpoint was between-treatment change from baseline in echocardiographic LVEF using a noninferiority margin of -3.5%. A total of 254 patients were randomly assigned to vildagliptin (n = 128) or placebo (n = 126). Baseline LVEF was 30.6 ± 6.8% in the vildagliptin group and 29.6 ± 7.7% in the placebo group. The adjusted mean change in LVEF was 4.95 ± 1.25% in vildagliptin treated patients and 4.33 ± 1.23% in placebo treated patients, a difference of 0.62 (95% confidence interval [CI]: -2.21 to 3.44; p = 0.667). This difference met the predefined noninferiority margin of -3.5%. Left ventricular end-diastolic and end-systolic volumes increased more in the vildagliptin group by 17.1 ml (95% CI: 4.6 to 29.5 ml; p = 0.007) and 9.4 ml (95% CI: -0.49 to 19.4 ml; p = 0.062), respectively. Decrease in hemoglobin A 1c  from baseline to 16 weeks, the main secondary endpoint, was greater in the vildagliptin group: -0.62% (95% CI: -0.93 to -0.30%; p < 0.001; -6.8 mmol/mol; 95% CI: -10.2 to -3.3 mmol/mol). Compared with placebo, vildagliptin had no major effect on LVEF but did lead to an increase in left ventricular volumes, the cause and clinical significance of which is unknown. More evidence is needed regarding the safety of dipeptidyl peptidase-4 inhibitors in patients with heart failure and left ventricular systolic dysfunction. (Effect of Vildagliptin on Left Ventricular Function in Patients With Type 2 Diabetes and Congestive Heart Failure; NCT00894868). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

ACCF/AHA/HFSA 2011 survey results: current staffing profile of heart failure programs, including programs that perform heart transplant and mechanical circulatory support device implantation.

PubMed

Jessup, Mariell; Albert, Nancy M; Lanfear, David E; Lindenfeld, JoAnn; Massie, Barry M; Walsh, Mary Norine; Zucker, Mark J

2011-05-01

There have been no published recommendations about staffing needs for a heart failure (HF) clinic or an office setting focused on heart transplant. The goal of this survey was to understand the current staffing environment of HF, transplant, and mechanical circulatory support device (MCSD) programs in the United States and abroad. This report identifies current staffing patterns but does not endorse a particular staffing model. An online survey, jointly sponsored by the American College of Cardiology Foundation (ACCF), American Heart Association (AHA), and the Heart Failure Society of America (HFSA), was sent to the members of all 3 organizations who had identified themselves as interested in HF, heart transplant, or both, between March 12, 2009, and May 12, 2009. The overall response rate to the 1,823 e-mail surveys was 23%. There were 257 unique practices in the United States (81% of total sites) and 58 international sites (19%); approximately 30% of centers were in a cardiovascular group practice and 30% in a medical school hospital setting. The large majority of practices delivered HF care in both an inpatient and outpatient environment, and slightly more centers were implanting MCSDs (47%) than performing cardiac transplantation (39%). Most practices (43%) were small, with <4 staff members, or small- to medium-sized (34%), with 4 to 10 staff members, with only 23% being medium (11-20 staff) or large programs (>20 staff). On average, a U.S. HF practice cared for 1,641 outpatients annually. An average HF program with transplant performed 10 transplants. Although larger programs were able to perform more transplants and see more outpatient HF visits, their clinician staffing volume tended to double for approximately every 500 to 700 additional HF visits annually. The average staffing utilization was 2.65 physician full-time equivalents (FTEs), 2.21 nonphysician practitioner (nurse practitioner or physician assistant) FTEs, and 2.61 nurse coordinator FTEs annually. The HF patient population is growing in number in the United States and internationally, and the clinicians who provide the highly skilled and time-consuming care to this population are under intense scrutiny as a result of focused quality improvement initiatives and reduced financial resources. Staffing guidelines should be developed to ensure that an adequate number of qualified professionals are hired for a given practice volume. These survey results are an initial step in developing such standards. Copyright © 2011. Published by Elsevier Inc.

Congestive Heart Failure Leads to Prolongation of the PR Interval and Atrioventricular Junction Enlargement and Ion Channel Remodelling in the Rabbit

PubMed Central

Nikolaidou, Theodora; Cai, Xue J.; Stephenson, Robert S.; Yanni, Joseph; Lowe, Tristan; Atkinson, Andrew J.; Jones, Caroline B.; Sardar, Rida; Corno, Antonio F.; Dobrzynski, Halina; Withers, Philip J.; Jarvis, Jonathan C.; Hart, George; Boyett, Mark R.

2015-01-01

Heart failure is a major killer worldwide. Atrioventricular conduction block is common in heart failure; it is associated with worse outcomes and can lead to syncope and bradycardic death. We examine the effect of heart failure on anatomical and ion channel remodelling in the rabbit atrioventricular junction (AVJ). Heart failure was induced in New Zealand rabbits by disruption of the aortic valve and banding of the abdominal aorta resulting in volume and pressure overload. Laser micro-dissection and real-time polymerase chain reaction (RT-PCR) were employed to investigate the effects of heart failure on ion channel remodelling in four regions of the rabbit AVJ and in septal tissues. Investigation of the AVJ anatomy was performed using micro-computed tomography (micro-CT). Heart failure animals developed first degree heart block. Heart failure caused ventricular myocardial volume increase with a 35% elongation of the AVJ. There was downregulation of HCN1 and Cx43 mRNA transcripts across all regions and downregulation of Cav1.3 in the transitional tissue. Cx40 mRNA was significantly downregulated in the atrial septum and AVJ tissues but not in the ventricular septum. mRNA abundance for ANP, CLCN2 and Navβ1 was increased with heart failure; Nav1.1 was increased in the inferior nodal extension/compact node area. Heart failure in the rabbit leads to prolongation of the PR interval and this is accompanied by downregulation of HCN1, Cav1.3, Cx40 and Cx43 mRNAs and anatomical enlargement of the entire heart and AVJ. PMID:26509807

Propofol Pharmacokinetics and Estimation of Fetal Propofol Exposure during Mid-Gestational Fetal Surgery: A Maternal-Fetal Sheep Model

PubMed Central

Niu, Jing; Venkatasubramanian, Raja; Vinks, Alexander A.; Sadhasivam, Senthilkumar

2016-01-01

Background Measuring fetal drug concentrations is extremely difficult in humans. We conducted a study in pregnant sheep to simultaneously describe maternal and fetal concentrations of propofol, a common intravenous anesthetic agent used in humans. Compared to inhalational anesthesia, propofol supplemented anesthesia lowered the dose of desflurane required to provide adequate uterine relaxation during open fetal surgery. This resulted in better intraoperative fetal cardiac outcome. This study describes maternal and fetal propofol pharmacokinetics (PK) using a chronically instrumented maternal-fetal sheep model. Methods Fetal and maternal blood samples were simultaneously collected from eight mid-gestational pregnant ewes during general anesthesia with propofol, remifentanil and desflurane. Nonlinear mixed-effects modeling was performed by using NONMEM software. Total body weight, gestational age and hemodynamic parameters were tested in the covariate analysis. The final model was validated by bootstrapping and visual predictive check. Results A total of 160 propofol samples were collected. A 2-compartment maternal PK model with a third fetal compartment appropriately described the data. Mean population parameter estimates for maternal propofol clearance and central volume of distribution were 4.17 L/min and 37.7 L, respectively, in a typical ewe with a median heart rate of 135 beats/min. Increase in maternal heart rate significantly correlated with increase in propofol clearance. The estimated population maternal-fetal inter-compartment clearance was 0.0138 L/min and the volume of distribution of propofol in the fetus was 0.144 L. Fetal propofol clearance was found to be almost negligible compared to maternal clearance and could not be robustly estimated. Conclusions For the first time, a maternal-fetal PK model of propofol in pregnant ewes was successfully developed. This study narrows the gap in our knowledge in maternal-fetal PK model in human. Our study confirms that maternal heart rate has an important influence on the pharmacokinetics of propofol during pregnancy. Much lower propofol concentration in the fetus compared to maternal concentrations explain limited placental transfer in in-vivo paired model, and less direct fetal cardiac depression we observed earlier with propofol supplemented inhalational anesthesia compared to higher dose inhalational anesthesia in humans and sheep. PMID:26752560

Continuous Positive Airway Pressure for Motion Management in Stereotactic Body Radiation Therapy to the Lung: A Controlled Pilot Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, Jeffrey D.; Lawrence, Yaacov R.; Sackler School of Medicine, Tel Aviv University, Tel Aviv

Objective: To determine the effect of continuous positive airway pressure (CPAP) on tumor motion, lung volume, and dose to critical organs in patients receiving stereotactic body radiation therapy (SBRT) for lung tumors. Methods and Materials: After institutional review board approval in December 2013, patients with primary or secondary lung tumors referred for SBRT underwent 4-dimensional computed tomographic simulation twice: with free breathing and with CPAP. Tumor excursion was calculated by subtracting the vector of the greatest dimension of the gross tumor volume (GTV) from the internal target volume (ITV). Volumetric and dosimetric determinations were compared with the Wilcoxon signed-rank test.more » CPAP was used during treatment if judged beneficial. Results: CPAP was tolerated well in 10 of the 11 patients enrolled. Ten patients with 18 lesions were evaluated. The use of CPAP decreased tumor excursion by 0.5 ± 0.8 cm, 0.4 ± 0.7 cm, and 0.6 ± 0.8 cm in the superior–inferior, right–left, and anterior–posterior planes, respectively (P≤.02). Relative to free breathing, the mean ITV reduction was 27% (95% confidence interval [CI] 16%-39%, P<.001). CPAP significantly augmented lung volume, with a mean absolute increase of 915 ± 432 cm{sup 3} and a relative increase of 32% (95% CI 21%-42%, P=.003), contributing to a 22% relative reduction (95% CI 13%-32%, P=.001) in mean lung dose. The use of CPAP was also associated with a relative reduction in mean heart dose by 29% (95% CI 23%-36%, P=.001). Conclusion: In this pilot study, CPAP significantly reduced lung tumor motion compared with free breathing. The smaller ITV, the planning target volume (PTV), and the increase in total lung volume associated with CPAP contributed to a reduction in lung and heart dose. CPAP was well tolerated, reproducible, and simple to implement in the treatment room and should be evaluated further as a novel strategy for motion management in radiation therapy.« less

Left Atrial Remodeling and Atrioventricular Coupling in a Canine Model of Early Heart Failure With Preserved Ejection Fraction

PubMed Central

Zakeri, Rosita; Moulay, Gilles; Chai, Qiang; Ogut, Ozgur; Hussain, Saad; Takahama, Hiroyuki; Lu, Tong; Wang, Xiao-Li; Linke, Wolfgang A.; Lee, Hon-Chi; Redfield, Margaret M.

2016-01-01

Background Left atrial (LA) compliance and contractility influence left ventricular (LV) stroke volume. We hypothesized that diminished LA compliance and contractile function occur early during development of heart failure with preserved ejection fraction (HFpEF) and impair overall cardiac performance. Method and Results Cardiac magnetic resonance imaging, echocardiography, LV and LA pressure-volume studies, and tissue analyses were performed in a model of early HFpEF (elderly dogs, renal wrap-induced hypertension, exogenous aldosterone; n=9) and young control dogs (sham surgery; n=13). Early HFpEF was associated with LA enlargement, cardiomyocyte hypertrophy and enhanced LA contractile function (median active emptying fraction 16% [95% CI 13–24] vs 12[10–14]%, p=0.008; end-systolic pressure-volume relationship slope 2.4[1.9–3.2]mmHg/mL HFpEF vs 1.5[1.2–2.2]mmHg/mL controls, p=0.01). However, atrioventricular coupling was impaired and the curvilinear LA end-reservoir pressure-volume relationship was shifted upward/leftward in HFpEF (LA stiffness constant, βLA, 0.16[0.11–0.18]mmHg/mL vs 0.06[0.04–0.10]mmHg/mL controls, p=0.002) indicating reduced LA compliance. Impaired atrioventricular coupling and lower LA compliance correlated with lower LV stroke volume. Total fibrosis and titin isoform composition were similar between groups, however titin was hyperphosphorylated in HFpEF and correlated with βLA. LA microvascular reactivity was diminished in HFpEF versus controls. LA microvascular density tended to be lower in HFpEF and inversely correlated with βLA. Conclusions In early-stage hypertensive HFpEF, LA cardiomyocyte hypertrophy, titin hyperphosphorylation and microvascular dysfunction occur in association with increased systolic and diastolic LA chamber stiffness, impaired atrioventricular coupling and decreased LV stroke volume. These data indicate that maladaptive LA remodeling occurs early during HFpEF development, supporting a concept of global myocardial remodeling. PMID:27758811

[Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

PubMed

Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

2017-10-01

Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Mortality-related resource utilization in the inpatient care of hypoplastic left heart syndrome.

PubMed

Danford, David A; Karels, Quentin; Kulkarni, Aparna; Hussain, Aysha; Xiao, Yunbin; Kutty, Shelby

2015-10-22

Quantifying resource utilization in the inpatient care of congenital heart diease is clinically relevant. Our purpose is to measure the investment of inpatient care resources to achieve survival in hypoplastic left heart syndrome (HLHS), and to determine how much of that investment occurs in hospitalizations that have a fatal outcome, the mortality-related resource utilization fraction (MRRUF). A collaborative administrative database, the Pediatric Health Information System (PHIS) containing data for 43 children's hospitals, was queried by primary diagnosis for HLHS admissions of patients ≤21 years old during 2004-2013. Institution, patient age, inpatient deaths, billed charges (BC) and length of stay (LOS) were recorded. In all, 11,122 HLHS admissions were identified which account for total LOS of 277,027 inpatient-days and $3,928,794,660 in BC. There were 1145 inpatient deaths (10.3%). LOS was greater among inpatient deaths than among patients discharged alive (median 17 vs. 12, p < 0.0001). BC were greater among inpatient deaths than among patients discharged alive (median 4.09 × 10(5) vs. 1.63 × 10(5), p < 0.0001). 16% of all LOS and 21% of all BC were accrued by patients who did not survive their hospitalization. These proportions showed no significant change year-by-year. The highest volume institutions had lower mortality rates, but there was no relation between institutional volume and the MRRUF. These data should alert providers and consumers that current practices often result in major resource expenditure for inpatient care of HLHS that does not result in survival to hospital dismissal. They highlight the need for data-driven critical review of standard practices to identify patterns of care associated with success, and to modify approaches objectively.

Serum concentrations of asymmetric and symmetric dimethylarginine are associated with mortality in acute heart failure patients.

PubMed

Potočnjak, Ines; Radulović, Bojana; Degoricija, Vesna; Trbušić, Matias; Pregartner, Gudrun; Berghold, Andrea; Meinitzer, Andreas; Frank, Saša

2018-06-15

Serum concentrations of asymmetric (ADMA) and symmetric (SDMA) dimethylarginine are established predictors of total and cardiovascular mortality. However, the predictive capacity of ADMA and SDMA for hospital and 3-months mortality of patients with acute heart failure (AHF) is unknown. Out of 152 included AHF patients, 79 (52%) were female, and the mean patient age was 75.2 ± 10.3 years. Hospital and three-month mortality rates were 14.5% and 27.4%, respectively. Serum ADMA and SDMA levels at admission, determined by reversed phase high performance liquid chromatography, were higher in patients having at least one of the three signs implying venous volume overload (enlarged liver, ascites, peripheral edema), a consequence of right-sided heart failure, compared to patients without those signs. Univariable logistic regression analyses revealed a significant positive association of ADMA and SDMA concentrations with hospital mortality [odds ratio (OR) and 95% confidence interval (CI) per standard deviation (SD) increase: 2.22 (1.37-3.79), p = 0.002, and 2.04 (1.34-3.18), p = 0.001, respectively], and 3-months mortality [2.06 (1.36-3.26), p = 0.001, and 2.52 (1.67-4.04), p < 0.001, respectively]. These associations remained significant after adjusting for age, sex, mean arterial pressure, low-density lipoprotein cholesterol, glomerular filtration rate, and N-terminal pro-brain natriuretic peptide. We conclude that ADMA and SDMA concentrations are associated with hospital and 3-month mortality and are increased by venous volume overload in AHF patients. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Progressive exercise preconditioning protects against circulatory shock during experimental heatstroke.

PubMed

Hung, Ching-Hsia; Chang, Nen-Chung; Cheng, Bor-Chih; Lin, Mao-Tsun

2005-05-01

Heat shock protein (HSP) 72 expression protects against arterial hypotension in rat heatstroke. HSP72 can also be induced in multiple organs, including hearts from rats with endurance exercise. We validated the hypothesis that progressive exercise preconditioning may confer cardiovascular protection during heatstroke by inducing the overexpression of HSP72 in multiple organs. To deal with the matter, we assessed the effects of heatstroke on mean arterial pressure, heart rate, cardiac output, stroke volume, total peripheral vascular resistance, colonic temperature, blood gases, and serum or tissue levels of tumor necrosis factor-alpha (TNF-alpha) in urethane-anesthetized rats pretreated without or with progressive exercise training for 1, 2, or 3 weeks. In addition, HSP72 expression in multiple organs was determined in different groups of animals. Heatstroke was induced by exposing the rats to a high blanket temperature (43 degrees C); the moment at which mean arterial pressure decreased from the peak value was taken as the time of heatstroke onset. Previous exercise training for 3 weeks, but not 1 or 2 weeks, conferred significant protection against hyperthermia, arterial hypotension, decreased cardiac output, decreased stroke volume, decreased peripheral vascular resistance, and increased levels of serum or tissue TNF-alpha during heatstroke and correlated with overexpression of HSP72 in multiple organs, including heart, liver, and adrenal gland. However, 10 days after 3 weeks of progressive exercise training, when HSP72 expression in multiple organs returned to basal values, the beneficial effects exerted by 3 weeks of exercise training were no longer observed. These results strongly suggest that HSP72 preconditioning with progressive exercise training protects against hyperthermia, circulatory shock, and TNF-alpha overproduction during heatstroke.

Left Recumbent Position Decreases Heart Rate without Alterations in Cardiac Autonomic Nervous System Activity in Healthy Young Adults.

PubMed

Sasaki, Konosuke; Haga, Mayu; Endo, Yoichi; Fujiwara, Junko; Maruyama, Ryoko

2017-04-01

Some studies have reported that recumbent position may have advantages in patients with heart disease and in pregnancy. However, it remains controversial whether recumbent position affects autonomic nervous system activity and hemodynamics in healthy adults. The aim of this study was to evaluate alterations in heart rate variability (HRV) and hemodynamics in the supine, left recumbent and right recumbent positions in healthy young adults. A total of 80 participants aged 22.8 ± 3.1 years were enrolled in this observational study. Fifty-eight volunteers (29 men and 29 women) maintained the supine position followed by the left and right recumbent positions, while electrocardiographic data were recorded for spectral analysis of HRV to assess cardiac vagal nerve and sympathetic nerve activities. The heart rate (HR) was significantly lower in the left recumbent position than in the other positions. There were no statistically significant differences in HRV among the three positions. Considering the possibility that the echographic procedure affects autonomic nervous system (ANS) activity, the other 22 participants (11 men and 11 women) underwent an echographic evaluation of hemodynamics in the heart and inferior vena cava (IVC) across the three positions. Although a low HR was also observed, there were no statistically significant differences in the IVC or the heart blood volume between the supine and the left recumbent positions. A postural change to the left recumbent position does not affect the cardiac blood circulation or ANS activity, though it does decrease HR in healthy young adults. This finding indicates that the lower HR in the left recumbent position is not attributable to the ANS activity.

Dissociation of heart rate variability and heart rate recovery in well-trained athletes.

PubMed

Lee, C Matthew; Mendoza, Albert

2012-07-01

The purpose of this investigation was to examine the relationships between aerobic fitness, volume of physical activity (PA), heart rate variability (HRV), and heart rate recovery (HRR) in a group of well-trained endurance athletes. Nineteen endurance athletes participated in this study and had aerobic capacities that placed them above the 99th percentile based on normative values (VO(2max): 67.1 ± 2 ml kg(-1) min(-1)). HRV was obtained via an EKG collected during supine rest and reported as high-frequency (HF), low-frequency (LF), and total power (TP). Natural log (ln) transformation was applied when variables violated assumptions of normality. HRR recovery was reported as the reduction in heart rate from peak exercise to the heart rate 1 min after cessation of exercise and PA was estimated from a questionnaire. HRR was significantly correlated with PA and VO(2max) (r = 0.67, P = 0.003 and 0.51, P = 0.039, respectively), but not with any index of HRV. Age was significantly correlated with lnHF (r = -0.49, P = 0.033), lnLF/lnHF (r = 0.48, P = 0.037), and normalized units (NU) of LF (r = 0.47, P = 0.042) and HF (r = -0.47, P = 0.042). Stepwise regression revealed that the strongest predictor of HRR was PA (R (2) = 0.45) and that VO(2max) did not add significant predictive value to the model. The relationship between HRV and age is evident in well-trained endurance athletes, whereas the relationship between HRV and PA/aerobic fitness is not. The maintained relationship between HRR and PA/aerobic fitness suggests that HRR may be a better marker of fitness-related differences in autonomic control in this population.

Peripheral Intravenous Volume Assessment (PIVA) for Quantitating Volume Overload in Patients Hospitalized with Acute Decompensated Heart Failure-a Pilot Study.

PubMed

Miles, Merrick; Alvis, Bret D; Hocking, Kyle; Baudenbacher, Franz; Guth, Christy; Lindenfeld, JoAann; Brophy, Colleen; Eagle, Susan

2018-05-16

To determine the feasibility of Peripheral Intravenous Volume Assessment (PIVA) of venous waveforms for assessing volume overload in patients admitted to the hospital with acute decompensated heart failure (ADHF). Venous waveforms were captured from a peripheral intravenous catheter in subjects admitted for ADHF and healthy age-matched controls. Admission PIVA signal, brain natriuretic peptide, and chest radiographic measurements were related to the net volume removed during diuresis. ADHF patients had a significantly greater PIVA signal on admission compared to the control group (P=0.0013, n=18). At discharge, ADHF patients had a PIVA signal similar to the control group. PIVA signal, not BNP or chest radiographic measures, accurately predicted the amount of volume removed during diuresis (R 2 =0.781, n=14). PIVA signal at time of discharge greater than 0.20, demonstrated 83.3% 120-day readmission rate. This study demonstrates the feasibility of PIVA for assessment of volume overload in patients admitted to the hospital with ADHF. Copyright © 2018. Published by Elsevier Inc.

Changes in cardiac output and tibial artery flow during and after progressive LBNP

NASA Technical Reports Server (NTRS)

1980-01-01

A 3.0 MHz Pulsed Doppler velocity meter (PD) was used to determine blood velocities in the ascending aorta from the suprasternal notch before, during and after progressive 5 min stages of lower body negative pressure (LBNP) in 7 subjects. Changes in stroke volume were calculated from the systolic velocity integrals. A unique 20 MHz PD was used to estimate bloodflow in the posterior tibial artery. With -20 torr mean stroke volume fell 11% and then continued to decline by 48% before LBNP was terminated. Mean tibial flow fell progressively with LBNP stress, due to an increase in reverse flow component and a reduction in peak forward flow and diameter. Stroke volume increased and heart rate fell dramatically during the first 15 sec of recovery. The LBNP was terminated early in 2 subjects because of vasovagal symptons (V). During V the stroke volume rose 86% which more than compensated for the drop in heart rate. This implies that V is accompanied by a paradoxical increase in venous return and that the reduction in HR is the primary cardiovascular event. During the first 15 sec of recovery these 2 subjects had a distinctive marked rise to heart rate reminiscent of the Bainbridge reflex.

Role of bioimpedance vectorial analysis in cardio-renal syndromes.

PubMed

Aspromonte, Nadia; Cruz, Dinna N; Ronco, Claudio; Valle, Roberto

2012-01-01

The cardio-renal syndromes (CRS) are the result of complex bidirectional organ cross-talk between the heart and kidney, with tremendous overlap of diseases such as coronary heart disease, heart failure (HF), and renal dysfunction in the same patient. Volume overload plays an important role in the pathophysiology of CRS. The appropriate treatment of overhydration, particularly in HF and in chronic kidney disease, has been associated with improved outcomes and blood pressure control. Clinical examination alone is often insufficient for accurate assessment of volume status because significant volume overload can exist even in the absence of peripheral or pulmonary edema on physical examination or radiography. Bioelectrical impedance techniques increasingly are being used in the management of patients with HF and those on chronic dialysis. These methods provide more objective estimates of volume status in such patients. Used in conjunction with standard clinical assessment and biomarkers such as the natriuretic peptides, bioimpedance analysis may be useful in guiding pharmacologic and ultrafiltration therapies and subsequently restoring such patients to a euvolemic or optivolemic state. In this article, we review the use of these techniques in CRS. Copyright © 2012 Elsevier Inc. All rights reserved.

Comparison of surgical conditions in 2 different anesthesia techniques of esmolol-induced controlled hypotension in breast reduction surgery

PubMed Central

Besir, Ahmet; Cekic, Bahanur; Kutanis, Dilek; Akdogan, Ali; Livaoglu, Murat

2017-01-01

Abstract Background: Breast reduction surgery is a common cosmetic surgery with a high incidence of blood loss and transfusion. In this surgery, the reduction of blood loss related to surgical manipulation and the volume of resected tissue is a target. In the present study, we compared the effects of esmolol-induced controlled hypotension on surgical visibility, surgical bleeding, and the duration of surgery in patients anesthetized with propofol/remifentanil (PR) or sevoflurane/remifentanil (SR). Methods: Patients in the American Society of Anesthesiologists I/II risk group undergoing breast reduction surgery were prospectively randomized into PR (n = 25) and SR (n = 25) groups. Controlled hypotension was induced with esmolol in both groups. During the intraoperative period, the heart rate (HR), mean arterial pressure (MAP), operation duration, volume of intraoperative blood loss, volume of blood received through postoperative drains, volume of resected tissues, and surgical area bleeding score were recorded. Results: The duration of operation in the incisional period was shorter in group PR compared to group SR (P = 0.04). The change in HR was lower in incision and hemostasis periods in the group PR compared to the group SR (P < 0.001). Total intraoperative intraoperative bleeding volume and volume of blood received through drains on postoperative postoperative day 1, day 2, and in total were found to be significantly lower in group PR compared to group SR. Surgical visibility scoring was more effective in group PR compared to SR. Conclusion: In the breast reduction surgery performed under esmolol-induced controlled hypotension, the effect of propofol + remifentanil anesthesia on the duration of incisional surgery, surgical visibility, and volume of surgical blood loss was more reliable and effective compared to that of sevoflurane + remifentanil, which seems to be an advantage. PMID:28272228

Total Artificial Heart Implantation Blood Pressure Management as Resolving Treatment for Massive Hemolysis following Total Artificial Heart Implantation.

PubMed

Ghodsizad, Ali; Koerner, Michael M; El-Banayosy, A; Zeriouh, Mohamed; Ruhparwar, Arjang; Loebe, Matthias

2016-10-21

The SynCardia Total Artificial Heart (TAH) has been used for patients with biventricular failure, who cannot be managed with implantation of a left ventricular (LV) assist device. Following TAH implantation, our patient developed severe hemolysis, which could only be managed successfully by aggressive blood pressure control [Ohashi 2003; Nakata 1998].

Ethical Analysis of Withdrawing Total Artificial Heart Support.

PubMed

DeMartino, Erin S; Wordingham, Sara E; Stulak, John M; Boilson, Barry A; Fuechtmann, Kayla R; Singh, Nausheen; Sulmasy, Daniel P; Pajaro, Octavio E; Mueller, Paul S

2017-05-01

To describe the characteristics of patients who undergo withdrawal of total artificial heart support and to explore the ethical aspects of withdrawing this life-sustaining treatment. We retrospectively reviewed the medical records of all adult recipients of a total artificial heart at Mayo Clinic from the program's inception in 2007 through June 30, 2015. Management of other life-sustaining therapies, approach to end-of-life decision making, engagement of ethics and palliative care consultation, and causes of death were analyzed. Of 47 total artificial heart recipients, 14 patients or their surrogates (30%) requested withdrawal of total artificial heart support. No request was denied by treatment teams. All 14 patients were supported with at least 1 other life-sustaining therapy. Only 1 patient was able to participate in decision making. It is widely held to be ethically permissible to withdraw a life-sustaining treatment when the treatment no longer meets the patient's health care-related goals (ie, the burdens outweigh the benefits). These data suggest that some patients, surrogates, physicians, and other care providers believe that this principle extends to the withdrawal of total artificial heart support. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Magnetic Resonance Characterization of Cardiac Adaptation and Myocardial Fibrosis in Pulmonary Hypertension Secondary to Systemic-To-Pulmonary Shunt.

PubMed

Pereda, Daniel; García-Lunar, Inés; Sierra, Federico; Sánchez-Quintana, Damián; Santiago, Evelyn; Ballesteros, Constanza; Encalada, Juan F; Sánchez-González, Javier; Fuster, Valentín; Ibáñez, Borja; García-Álvarez, Ana

2016-09-01

Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are strong predictors of morbidity and mortality among patients with congenital heart disease. Early detection of RV involvement may be useful in the management of these patients. We aimed to assess progressive cardiac adaptation and quantify myocardial extracellular volume in an experimental porcine model of PH because of aorto-pulmonary shunt using cardiac magnetic resonance (CMR). To characterize serial cardiac adaptation, 12 pigs (aorto-pulmonary shunt [n=6] or sham operation [n=6]) were evaluated monthly with right heart catheterization, CMR, and computed tomography during 4 months, followed by pathology analysis. Extracellular volume by CMR in different myocardial regions was studied in 20 animals (aorto-pulmonary shunt [n=10] or sham operation [n=10]) 3 months after the intervention. All shunted animals developed PH. CMR evidenced progressive RV hypertrophy and dysfunction secondary to increased afterload and left ventricular dilatation secondary to volume overload. Shunt flow by CMR strongly correlated with PH severity, left ventricular end-diastolic pressure, and left ventricular dilatation. T1-mapping sequences demonstrated increased extracellular volume at the RV insertion points, the interventricular septum, and the left ventricular lateral wall, reproducing the pattern of fibrosis found on pathology. Extracellular volume at the RV insertion points strongly correlated with pulmonary hemodynamics and RV dysfunction. Prolonged systemic-to-pulmonary shunting in growing piglets induces PH with biventricular remodeling and myocardial fibrosis that can be detected and monitored using CMR. These results may be useful for the diagnosis and management of congenital heart disease patients with pulmonary overcirculation. © 2016 American Heart Association, Inc.

Vortex-ring mixing as a measure of diastolic function of the human heart: Phantom validation and initial observations in healthy volunteers and patients with heart failure.

PubMed

Töger, Johannes; Kanski, Mikael; Arvidsson, Per M; Carlsson, Marcus; Kovács, Sándor J; Borgquist, Rasmus; Revstedt, Johan; Söderlind, Gustaf; Arheden, Håkan; Heiberg, Einar

2016-06-01

To present and validate a new method for 4D flow quantification of vortex-ring mixing during early, rapid filling of the left ventricle (LV) as a potential index of diastolic dysfunction and heart failure. 4D flow mixing measurements were validated using planar laser-induced fluorescence (PLIF) in a phantom setup. Controls (n = 23) and heart failure patients (n = 23) were studied using 4D flow at 1.5T (26 subjects) or 3T (20 subjects) to determine vortex volume (VV) and inflowing volume (VVinflow ). The volume mixed into the vortex-ring was quantified as VVmix-in = VV-VVinflow . The mixing ratio was defined as MXR = VVmix-in /VV. Furthermore, we quantified the fraction of the end-systolic volume (ESV) mixed into the vortex-ring (VVmix-in /ESV) and the fraction of the LV volume at diastasis (DV) occupied by the vortex-ring (VV/DV). PLIF validation of MXR showed fair agreement (R(2) = 0.45, mean ± SD 1 ± 6%). MXR was higher in patients compared to controls (28 ± 11% vs. 16 ± 10%, P < 0.001), while VVmix-in /ESV and VV/DV were lower in patients (10 ± 6% vs. 18 ± 12%, P < 0.01 and 25 ± 8% vs. 50 ± 6%, P < 0.0001). Vortex-ring mixing can be quantified using 4D flow. The differences in mixing parameters observed between controls and patients motivate further investigation as indices of diastolic dysfunction. J. Magn. Reson. Imaging 2016;43:1386-1397. © 2015 Wiley Periodicals, Inc.

Radiobiological Determination of Dose Escalation and Normal Tissue Toxicity in Definitive Chemoradiation Therapy for Esophageal Cancer☆

PubMed Central

Warren, Samantha; Partridge, Mike; Carrington, Rhys; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A.

2014-01-01

Purpose This study investigated the trade-off in tumor coverage and organ-at-risk sparing when applying dose escalation for concurrent chemoradiation therapy (CRT) of mid-esophageal cancer, using radiobiological modeling to estimate local control and normal tissue toxicity. Methods and Materials Twenty-one patients with mid-esophageal cancer were selected from the SCOPE1 database (International Standard Randomised Controlled Trials number 47718479), with a mean planning target volume (PTV) of 327 cm3. A boost volume, PTV2 (GTV + 0.5 cm margin), was created. Radiobiological modeling of tumor control probability (TCP) estimated the dose required for a clinically significant (+20%) increase in local control as 62.5 Gy/25 fractions. A RapidArc (RA) plan with a simultaneously integrated boost (SIB) to PTV2 (RA62.5) was compared to a standard dose plan of 50 Gy/25 fractions (RA50). Dose-volume metrics and estimates of normal tissue complication probability (NTCP) for heart and lungs were compared. Results Clinically acceptable dose escalation was feasible for 16 of 21 patients, with significant gains (>18%) in tumor control from 38.2% (RA50) to 56.3% (RA62.5), and only a small increase in predicted toxicity: median heart NTCP 4.4% (RA50) versus 5.6% (RA62.5) P<.001 and median lung NTCP 6.5% (RA50) versus 7.5% (RA62.5) P<.001. Conclusions Dose escalation to the GTV to improve local control is possible when overlap between PTV and organ-at-risk (<8% heart volume and <2.5% lung volume overlap for this study) generates only negligible increase in lung or heart toxicity. These predictions from radiobiological modeling should be tested in future clinical trials. PMID:25304796

Cardiopulmonary function and oxygen delivery during total liquid ventilation.

PubMed

Tsagogiorgas, Charalambos; Alb, Markus; Herrmann, Peter; Quintel, Michael; Meinhardt, Juergen P

2011-10-01

Total liquid ventilation (TLV) with perfluorocarbons has shown to improve cardiopulmonary function in the injured and immature lung; however there remains controversy over the normal lung. Hemodynamic effects of TLV in the normal lung currently remain undetermined. This study compared changes in cardiopulmonary and circulatory function caused by either liquid or gas tidal volume ventilation. In a prospective, controlled study, 12 non-injured anesthetized, adult New Zealand rabbits were primarily conventionally gas-ventilated (CGV). After instrumentation for continuous recording of arterial (AP), central venous (CVP), left artrial (LAP), pulmonary arterial pressures (PAP), and cardiac output (CO) animals were randomized into (1) CGV group and (2) TLV group. In the TLV group partial liquid ventilation was initiated with instillation of perfluoroctylbromide (12 ml/kg). After 15 min, TLV was established for 3 hr applying a volume-controlled, pressure-limited, time-cycled ventilation mode using a double-piston configured TLV. Controls (CGV) remained gas-ventilated throughout the experiment. During TLV, heart rate, CO, PAP, MAP, CVP, and LAP as well as derived hemodynamic variables, arterial and mixed venous blood gases, oxygen delivery, PVR, and SVR did not differ significantly compared to CGV. Liquid tidal volumes suitable for long-term TLV in non-injured rabbits do not significantly impair CO, blood pressure, and oxygen dynamics when compared to CGV. Copyright © 2011 Wiley-Liss, Inc.

[Camera-cinematography of the heart (author's transl)].

PubMed

Adam, W E; Meyer, G; Bitter, F; Kampmann, H; Bargon, G; Stauch, M

1975-07-01

By "camera-cinematography" of the heart, we mean an isotope method which permits detailed observation of cardiac mechanics without the use of a catheter. All that is necessary is an intravenous injection of 10 to 15 mCi 99mTc human serum albumen followed after ten minutes by a five to ten minute period of observation with a scintilation camera. At this time the isotope has become distributed in the blood. Variations in the precordial impulses correspond with intra-cardiac changes of blood volume during a cardiac cycle. Analysis of the R-wave provides adequate information of cyclical volume changes in limited portions of the heart. This is achieved by a monitor with a pseudo-3-dimensional display; contraction and relaxation of the myocardium can be shown for any chosen longitudinal or horizontal diameter of the heart. Our programme allows simultaneous presentation of the movement of any point on the myocardium as a time-activity curve. The method is recommended as an addition to chest radiography, heart screening or cardiac kymography before carrying out cardiac catheterisation.

A blood circulation model for reference man

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, R.W.; Eckerman, K.F.; Williams, L.R.

This paper describes a dynamic blood circulation model that predicts the movement and gradual dispersal of a bolus of material in the circulation after its intravascular injection into an adult human. The main purpose of the model is to improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The total blood volume is partitioned into the blood contents of 24 separate organs or tissues, right heart chambers, left heart chambers, pulmonary circulation, arterial outflow to the systemic tissues (aorta and large arteries), and venous return from the systemic tissues (large veins). As amore » compromise between physical reality and computational simplicity, the circulation of blood is viewed as a system of first-order transfers between blood pools, with the delay time depending on the mean transit time across the pool. The model allows consideration of incomplete, tissue-dependent extraction of material during passage through the circulation and return of material from tissues to plasma.« less

STS-40 Mission Specialist (MS) Seddon on ergometer conducts Exp. No. 066

NASA Image and Video Library

1991-06-14

STS040-211-019 (5-14 June 1991) --- Astride the bicycle ergometer, astronaut Rhea Seddon, mission specialist, breathes into the cardiovascular re-breathing unit during the exercise phase of an experiment. The investigation, In-flight Study of Cardiovascular Deconditioning (Experiment 066), was developed by Dr. Leon E. Farhi of the State University of New York in Buffalo. It focuses on the deconditioning of the heart and lungs and changes in cardiopulmonary function that occur upon return to Earth. By using non-invasive techniques of prolonged expiration and re-breathing, investigators can determine the amount of blood pumped out of the heart (cardiac output), the ease with which blood flows through all the vessels (total peripheral resistance), oxygen used and carbon dioxide released by the body, and lung function and volume changes. Measurements are made both while crew members are resting and while they pedal the exercise bicycle, as Dr. Seddon is doing here. This scene was photographed with a 35mm camera.

Perioperative Care of the Patient With the Total Artificial Heart.

PubMed

Yaung, Jill; Arabia, Francisco A; Nurok, Michael

2017-05-01

Advanced heart failure continues to be a leading cause of morbidity and mortality despite improvements in pharmacologic therapy. High demand for cardiac transplantation and shortage of donor organs have led to an increase in the utilization of mechanical circulatory support devices. The total artificial heart is an effective biventricular assist device that may be used as a bridge to transplant and that is being studied for destination therapy. This review discusses the history, indications, and perioperative management of the total artificial heart with emphasis on the postoperative concerns.

Total Artificial Heart Implantation After Undifferentiated High-Grade Sarcoma Excision

PubMed Central

Kremer, Jamila; Farag, Mina; Arif, Rawa; Brcic, Andreas; Sabashnikov, Anton; Schmack, Bastian; Popov, Aron-Frederik; Karck, Matthias; Dohmen, Pascal M.; Ruhparwar, Arjang; Weymann, Alexander

2016-01-01

Background Total artificial heart (TAH) implantation in patients with aggressive tumor infiltration of the heart can be challenging. Case Report We report on a patient with a rare primary undifferentiated high-grade spindle cell sarcoma of the mitral valve and in the left atrium, first diagnosed in 2014. The referring center did a first resection in 2014. In the course of 17 months, computer tomography (CT) scan again showed massive invasion of the mitral valve and left atrium. Partial resection and mitral valve replacement was not an option. We did a subtotal heart excision with total artificial heart implantation. In this report we discuss complications, risk factors, and perioperative management of this patient. Conclusions Patients with aggressive tumors of the heart can be considered for TAH implantation. PMID:27803495

Total Artificial Heart Implantation After Undifferentiated High-Grade Sarcoma Excision.

PubMed

Kremer, Jamila; Farag, Mina; Arif, Rawa; Brcic, Andreas; Sabashnikov, Anton; Schmack, Bastian; Popov, Aron-Frederik; Karck, Matthias; Dohmen, Pascal M; Ruhparwar, Arjang; Weymann, Alexander

2016-11-02

BACKGROUND Total artificial heart (TAH) implantation in patients with aggressive tumor infiltration of the heart can be challenging. CASE REPORT We report on a patient with a rare primary undifferentiated high-grade spindle cell sarcoma of the mitral valve and in the left atrium, first diagnosed in 2014. The referring center did a first resection in 2014. In the course of 17 months, computer tomography (CT) scan again showed massive invasion of the mitral valve and left atrium. Partial resection and mitral valve replacement was not an option. We did a subtotal heart excision with total artificial heart implantation. In this report we discuss complications, risk factors, and perioperative management of this patient. CONCLUSIONS Patients with aggressive tumors of the heart can be considered for TAH implantation.

Machines versus medication for biventricular heart failure: focus on the total artificial heart.

PubMed

Arabia, Francisco A; Moriguchi, Jaime D

2014-09-01

The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

The Visible Heart® project and free-access website 'Atlas of Human Cardiac Anatomy'.

PubMed

Iaizzo, Paul A

2016-12-01

Pre- and post-evaluations of implantable cardiac devices require innovative and critical testing in all phases of the design process. The Visible Heart ® Project was successfully launched in 1997 and 3 years later the Atlas of Human Cardiac Anatomy website was online. The Visible Heart ® methodologies and Atlas website can be used to better understand human cardiac anatomy, disease states and/or to improve cardiac device design throughout the development process. To date, Visible ® Heart methodologies have been used to reanimate 75 human hearts, all considered non-viable for transplantation. The Atlas is a unique free-access website featuring novel images of functional and fixed human cardiac anatomies from >400 human heart specimens. Furthermore, this website includes education tutorials on anatomy, physiology, congenital heart disease and various imaging modalities. For instance, the Device Tutorial provides examples of commonly deployed devices that were present at the time of in vitro reanimation or were subsequently delivered, including: leads, catheters, valves, annuloplasty rings, leadless pacemakers and stents. Another section of the website displays 3D models of vasculature, blood volumes, and/or tissue volumes reconstructed from computed tomography (CT) and magnetic resonance images (MRI) of various heart specimens. A new section allows the user to interact with various heart models. Visible Heart ® methodologies have enabled our laboratory to reanimate 75 human hearts and visualize functional cardiac anatomies and device/tissue interfaces. The website freely shares all images, video clips and CT/MRI DICOM files in honour of the generous gifts received from donors and their families. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

Reduced lung dose during radiotherapy for thoracic esophageal carcinoma: VMAT combined with active breathing control for moderate DIBH.

PubMed

Gong, Guanzhong; Wang, Ruozheng; Guo, Yujie; Zhai, Deyin; Liu, Tonghai; Lu, Jie; Chen, Jinhu; Liu, Chengxin; Yin, Yong

2013-12-20

Lung radiation injury is a critical complication of radiotherapy (RT) for thoracic esophageal carcinoma (EC). Therefore, the goal of this study was to investigate the feasibility and dosimetric effects of reducing the lung tissue irradiation dose during RT for thoracic EC by applying volumetric modulated arc radiotherapy (VMAT) combined with active breathing control (ABC) for moderate deep inspiration breath-hold (mDIBH). Fifteen patients with thoracic EC were randomly selected to undergo two series of computed tomography (CT) simulation scans with ABC used to achieve mDIBH (representing 80% of peak DIBH value) versus free breathing (FB). Gross tumor volumes were contoured on different CT images, and planning target volumes (PTVs) were obtained using different margins. For PTV-FB, intensity-modulated radiotherapy (IMRT) was designed with seven fields, and VMAT included two whole arcs. For PTV-DIBH, VMAT with three 135° arcs was applied, and the corresponding plans were named: IMRT-FB, VMAT-FB, and VMAT-DIBH, respectively. Dosimetric differences between the different plans were compared. The heart volumes decreased by 19.85%, while total lung volume increased by 52.54% in mDIBH, compared to FB (p < 0.05). The mean conformality index values and homogeneity index values for VMAT-DIBH (0.86, 1.07) were slightly worse than those for IMRT-FB (0.90, 1.05) and VMAT-FB (0.90, 1.06) (p > 0.05). Furthermore, compared to IMRT-FB and VMAT-FB, VMAT-DIBH reduced the mean total lung dose by 18.64% and 17.84%, respectively (p < 0.05); moreover, the V5, V10, V20, and V30 values for IMRT-FB and VMAT-FB were reduced by 10.84% and 10.65% (p > 0.05), 12.5% and 20% (p < 0.05), 30.77% and 33.33% (p < 0.05), and 50.33% and 49.15% (p < 0.05), respectively. However, the heart dose-volume indices were similar between VMAT-DIBH and VMAT-FB which were lower than IMRT-FB without being statistically significant (p > 0.05). The monitor units and treatment time of VMAT-DIBH were also the lowest (p < 0.05). VMAT combined with ABC to achieve mDIBH is a feasible approach for RT of thoracic EC. Furthermore, this method has the potential to effectively reduce lung dose in a shorter treatment time and with better targeting accuracy.

ABO-incompatible blood transfusion and invasive therapeutic approaches during pediatric cardiopulmonary bypass.

PubMed

Aliç, Yasin; Akpek, Elif A; Dönmez, Asli; Ozkan, Süleyman; Perfusionist, Güray Yener; Aslamaci, Sait

2008-10-01

Human error has been identified as a major source of ABO-incompatible blood transfusion which most often results from blood being given to the wrong patient. We present a case of inadvertent administration of ABO-incompatible blood to a 6-mo-old child who underwent congenital heart surgery and discuss the use of invasive therapeutic approaches. Invasive techniques included total circulatory arrest and large-volume exchange transfusion, along with conventional ultrafiltration and plasmapheresis, which could all be performed rapidly and effectively. The combination of standard pharmacologic therapies and alternative invasive techniques after a massive ABO-incompatible blood transfusion led to a favorable outcome in our patient.

Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

PubMed

Kleinheyer, Matthias; Timms, Daniel L; Tansley, Geoffrey D; Nestler, Frank; Greatrex, Nicholas A; Frazier, O Howard; Cohn, William E

2016-09-01

Unlike the earlier reciprocating volume displacement-type pumps, rotary blood pumps (RBPs) typically operate at a constant rotational speed and produce continuous outflow. When RBP technology is used in constructing a total artificial heart (TAH), the pressure waveform that the TAH produces is flat, without the rise and fall associated with a normal arterial pulse. Several studies have suggested that pulseless circulation may impair microcirculatory perfusion and the autoregulatory response and may contribute to adverse events such as gastrointestinal bleeding, arteriovenous malformations, and pump thrombosis. It may therefore be beneficial to attempt to reproduce pulsatile output, similar to that generated by the native heart, by rapidly modulating the speed of an RBP impeller. The choice of an appropriate speed profile and control strategy to generate physiologic waveforms while minimizing power consumption and blood trauma becomes a challenge. In this study, pump operation modes with six different speed profiles using the BiVACOR TAH were evaluated in vitro. These modes were compared with respect to: hemodynamic pulsatility, which was quantified as surplus hemodynamic energy (SHE); maximum rate of change of pressure (dP/dt); pulse power index; and motor power consumption as a function of pulse pressure. The results showed that the evaluated variables underwent different trends in response to changes in the speed profile shape. The findings indicated a possible trade-off between SHE levels and flow rate pulsatility related to the relative systolic duration in the speed profile. Furthermore, none of the evaluated measures was sufficient to fully characterize hemodynamic pulsatility. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Beat-by-beat analysis of cardiac output and blood pressure responses to short-term barostimulation in different body positions

NASA Astrophysics Data System (ADS)

Hildebrandt, Wulf; Schütze, Harald; Stegemann, J.

Rapid quantification of the human baro-reflex control of heart rate has been achieved on a beat-by-beat basis using a neck-chamber with quick ECG-triggered pressure changes. Referring to recent findings on heart rate and stroke volume, the present study uses this technique to compare cardiac output as well as blood pressure changes in supine and upright position to investigate feedback effects and to confirm postural reflex modifications not revealed by RR-interval changes. A suction profile starting at +40 mmHg and running 7 steps of pressure decrease down to -65 mmHg was examined in 0° and 90° tilting position while beat-by-beat recordings were done of heart rate, stroke volume (impedance-cardiography) and blood pressure (Finapres tm) (n=16). The percentual heart rate decrease failed to be significantly different between positions. A suction-induced stroke volume increase led to a cardiac output almost maintained when supine and significantly increased when upright. A decrease in all blood pressure values was found during suction, except for systolic values in upright position which increased. Conclusively, (a) it is confirmed that different inotropy accounts for the seen gravitational effect on the cardiac output not represented by heart rate; (b) identical suction levels in different positions lead to different stimuli at the carotid receptor. This interference has to be considered in microgravity studies by beat-by-beat measurement of cardiac output and blood pressure.

The Impact of Hospital Size on CMS Hospital Profiling.

PubMed

Sosunov, Eugene A; Egorova, Natalia N; Lin, Hung-Mo; McCardle, Ken; Sharma, Vansh; Gelijns, Annetine C; Moskowitz, Alan J

2016-04-01

The Centers for Medicare & Medicaid Services (CMS) profile hospitals using a set of 30-day risk-standardized mortality and readmission rates as a basis for public reporting. These measures are affected by hospital patient volume, raising concerns about uniformity of standards applied to providers with different volumes. To quantitatively determine whether CMS uniformly profile hospitals that have equal performance levels but different volumes. Retrospective analysis of patient-level and hospital-level data using hierarchical logistic regression models with hospital random effects. Simulation of samples including a subset of hospitals with different volumes but equal poor performance (hospital effects=+3 SD in random-effect logistic model). A total of 1,085,568 Medicare fee-for-service patients undergoing 1,494,993 heart failure admissions in 4930 hospitals between July 1, 2005 and June 30, 2008. CMS methodology was used to determine the rank and proportion (by volume) of hospitals reported to perform "Worse than US National Rate." Percent of hospitals performing "Worse than US National Rate" was ∼40 times higher in the largest (fifth quintile by volume) compared with the smallest hospitals (first quintile). A similar gradient was seen in a cohort of 100 hospitals with simulated equal poor performance (0%, 0%, 5%, 20%, and 85% in quintiles 1 to 5) effectively leaving 78% of poor performers undetected. Our results illustrate the disparity of impact that the current CMS method of hospital profiling has on hospitals with higher volumes, translating into lower thresholds for detection and reporting of poor performance.

Mean circulatory filling pressure: potential problems with measurement.

PubMed

Gaddis, M L; Rothe, C F; Tunin, R S; Moran, M; MacAnespie, C L

1986-10-01

Three experimental series using 22 acutely splenectomized mongrel dogs were completed to 1) compare fibrillation (Fib) and acetylcholine (ACh) injection as methods to stop the heart for the mean circulatory filling pressure (Pmcf) maneuver, and 2) test whether Pmcf equals portal venous pressure 7 s after heart stoppage (Pportal7s). Blood volume changes of -10, -20, +10, or +20 ml/kg were imposed and Pmcf and Pportal measurements were obtained. Pportal7s and Pmcf were significantly different with volume depletion but were similar under control conditions. Pmcf with ACh and Pmcf with Fib were significantly different only after a volume change of -20 ml/kg. However, severe pulmonary congestion and atelectasis were detected in animals where Ach was used to stop the heart. In some cases (with injection directly into the pulmonary artery) the damage was severe enough to cause irreversible arterial hypoxia. Thus we conclude that the repeated use of ACh may exert a detrimental influence on pulmonary function, changing the physiological status of the experimental animal. Also, the central venous pressure at 7 s of heart stoppage (Pcv7s) is not a fully accurate estimate of the true mean circulatory filling pressure during the Pmcf maneuver, because Pcv7s did not equal the Pportal7s under all experimental conditions.

Effects of local irradiation combined with sunitinib on early remodeling, mitochondria, and oxidative stress in the rat heart

PubMed Central

Sridharan, Vijayalakshmi; Thomas, Chanice J.; Cao, Maohua; Melnyk, Stepan B.; Pavliv, Oleksandra; Joseph, Jacob; Singh, Sharda P.; Sharma, Sunil; Moros, Eduardo G.; Boerma, Marjan

2016-01-01

Background and Purpose Thoracic (chemo)radiation therapy is increasingly administered with tyrosine kinase inhibitors (TKI). While TKI have adverse effects on the heart, it is unknown whether combination with other cancer therapies causes enhanced toxicity. We used an animal model to investigate whether radiation and sunitinib interact in their effects on the heart. Material and Methods Male Sprague-Dawley rats received local heart irradiation (9 Gy per day, 5 days). Oral sunitinib (8 or 15 mg/kg bodyweight per day) started on day 1 of irradiation and continued for 2 weeks. Cardiac function was examined with echocardiography. Cardiac remodeling, cell death, left ventricular (LV) oxidative stress markers, mitochondrial morphology and membrane permeability transition pore (mPTP) opening were assessed. Results Cardiac diameter, stroke volume, and LV volume, mass and anterior wall thickness increased in time, but only in the vehicle group. Sunitinib reduced LV inner diameter and volume in systole, which were counteracted by radiation. Sunitinib and radiation showed enhanced effects on mitochondrial morphology and mPTP opening, but not on cardiac troponin I, mast cell numbers or markers of oxidative stress. Conclusions This study found no early enhanced effects of radiation and sunitinib on cardiac function or structure. Long-term effects remain to be determined. PMID:27072940

Total artificial heart implantation in a young Marfan syndrome patient.

PubMed

Rao, Prashant; Keenan, Jack B; Rajab, Taufiek K; Kim, Samuel; Smith, Richard; Amabile, Orazio; Khalpey, Zain

2018-03-01

Cardiovascular complications represent the leading cause of morbidity and mortality in patients with Marfan syndrome. Here, we describe a unique case where a total artificial heart was implanted in a young Marfan syndrome woman. A 22-year-old postpartum African American female with Marfan syndrome developed multiple severe valve dysfunction and biventricular failure that was refractory to medical management. She previously had a Bentall procedure for Type A aortic dissection and repair of a Type B dissection. We implanted a total artificial heart with a good outcome. Total artificial heart is a durable option for severe biventricular failure and multiple valvular dysfunction as a bridge to transplant in a young patient with Marfan syndrome.

Quantification of free and total bisphenol A and bisphenol B in human urine by dispersive liquid-liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography-mass spectrometry (MD-GC/MS).

PubMed

Cunha, S C; Fernandes, J O

2010-11-15

A novel method combining dispersive liquid-liquid microextraction (DLLME) and heart-cutting multidimensional gas chromatography coupled to mass spectrometry was developed for the determination of free and total bisphenol A (BPA) and bisphenol B (BPB) in human urine samples. The DLLME procedure combines extraction, derivatization and concentration of the analytes into one step. Several important variables influencing the extraction efficiency and selectivity such as nature and volume of extractive and dispersive solvents as well as the amount of acetylating reagent were investigated. The temperature and time to hydrolyze BPA and BPB conjugates with a β-glucuronidase and sulfatase enzyme preparation were also studied. Under the optimized conditions good efficiency extraction (71-93%) and acceptable total DLLME yields (56-77%) were obtained for both analytes. Matrix-matched calibration curves were linear with correlation coefficients higher than 0.996 in the range level 0.1-5 μg/l, and the relative standard deviations (%RSD) were lower than 20% (n=6). The limits of detection were 0.03 and 0.05 μg/l for BPA and BPB, respectively. The applicability of the proposed method for determining urinary free and total BPA and BPB was assessed by analyzing the human urine of a group of 20 volunteers. Free BPA was detected in 45% of the sample whereas total BPA was detected in 85% of the samples at concentrations ranging between 0.39 and 4.99 μg/l. BPB was detected in conjugated form in two samples. Copyright © 2010 Elsevier B.V. All rights reserved.

Dosimetric Considerations in Respiratory-Gated Deep Inspiration Breath-Hold for Left Breast Irradiation.

PubMed

Walston, Steve; Quick, Allison M; Kuhn, Karla; Rong, Yi

2017-02-01

To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol. Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy. Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison. The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans. Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V 20 or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association. It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose. Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold. Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.

Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

PubMed

Kawabori, Masashi; Kurihara, Chitaru; Miller, Yair; Heck, Kent A; Bogaev, Roberta C; Civitello, Andrew B; Cohn, William E; Frazier, O H; Morgan, Jeffrey A

2017-09-01

Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

Extracorporeal total artificial heart as bailout surgery.

PubMed

Perrodin, Stéphanie F; Muller, Olivier; Gronchi, Fabrizio; Liaudet, Lucas; Hullin, Roger; Kirsch, Matthias

2017-03-01

We report the use of a total extracorporeal heart for uncontrolled bleeding following a proximal left anterior descending artery perforation, using two centrifugal ventricular assist devices after heart explantation. The literature describing similar techniques and patient outcomes for this "bailout" technique are reviewed. © 2017 Wiley Periodicals, Inc.

Dosimetric evaluation of total marrow irradiation using 2 different planning systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nalichowski, Adrian, E-mail: nalichoa@karmanos.org; Eagle, Don G.; Burmeister, Jay

This study compared 2 different treatment planning systems (TPSs) for quality and efficiency of total marrow irradiation (TMI) plans. The TPSs used in this study were VOxel-Less Optimization (VoLO) (Accuray Inc, Sunnyvale, CA) using helical dose delivery on a Tomotherapy Hi-Art treatment unit and Eclipse (Varian Medical Systems Inc, Palo Alto, CA) using volumetric modulated arc therapy (VMAT) dose delivery on a Varian iX treatment unit. A total dose of 1200 cGy was prescribed to cover 95% of the planning target volume (PTV). The plans were optimized and calculated based on a single CT data and structure set using themore » Alderson Rando phantom (The Phantom Laboratory, Salem, NY) and physician contoured target and organ at risk (OAR) volumes. The OARs were lungs, heart, liver, kidneys, brain, and small bowel. The plans were evaluated based on plan quality, time to optimize the plan and calculate the dose, and beam on time. The resulting mean and maximum doses to the PTV were 1268 and 1465 cGy for VoLO and 1284 and 1541 cGy for Eclipse, respectively. For 5 of 6 OAR structures the VoLO system achieved lower mean and D10 doses ranging from 22% to 52% and 3% to 44%, respectively. Total computational time including only optimization and dose calculation were 0.9 hours for VoLO and 3.8 hours for Eclipse. These times do not include user-dependent target delineation and field setup. Both planning systems are capable of creating high-quality plans for total marrow irradiation. The VoLO planning system was able to achieve more uniform dose distribution throughout the target volume and steeper dose fall off, resulting in superior OAR sparing. VoLO's graphics processing unit (GPU)–based optimization and dose calculation algorithm also allowed much faster creation of TMI plans.« less

Research to improve the accuracy of determining the stroke volume of an artificial ventricle using the wavelet transform

NASA Astrophysics Data System (ADS)

Grad, Leszek; Murawski, Krzysztof; Sulej, Wojciech

2017-08-01

In the article we presented results obtained during research, which are the continuation of work on the use of artificial neural networks to determine the relationship between the view of the membrane and the stroke volume of the blood chamber of the mechanical prosthetic heart. The purpose of the research was to increase the accuracy of determining the blood chamber volume. Therefore, the study was focused on the technique of the features that the image extraction gives. During research we used the wavelet transform. The achieved results were compared to the results obtained by other previous methods. Tests were conducted on the same mechanical prosthetic heart model used in previous experiments.

Right heart overload contributes to cardiac natriuretic hormone elevation in patients with heart failure.

PubMed

Passino, Claudio; Maria Sironi, Anna; Favilli, Brunella; Poletti, Roberta; Prontera, Concetta; Ripoli, Andrea; Lombardi, Massimo; Emdin, Michele

2005-09-15

Atrial and brain natriuretic peptides (ANP and BNP) plasma concentration increases and holds a prognostic significance in patients with left ventricular dysfunction. We assessed the hypothesis that right ventricular (RV) overload might significantly contribute to plasma elevation of cardiac natriuretic hormones in patients with heart failure. Forty-one patients with cardiomyopathy and depressed left ventricular (LV) function (ejection fraction, EF, <40%), underwent cardiac magnetic resonance imaging (MRI) and resting plasma determination of ANP and BNP. Nineteen healthy subjects were also studied as control group. Ventricular volumes and function were assessed by MRI. In the group of patients, LVEF was 22.6+/-1.2% (controls: 61.2+/-1.3%, P<0.001, mean+/-S.E.M.), while RVEF was 48.2+/-2.5% (controls: 66.7+/-1.6%, P<0.001); LV and RV end diastolic/systolic volumes, corrected by body surface area, were 143+/-7/114+/-7 ml/m2 (controls 70+/-3/27+/-2 ml/m2, both P<0.001) and 66+/-3/37+/-4 ml/m2 (controls: 63+/-4/21+/-2 ml/m2, P<0.01 only for end-systolic volume). BNP plasma value was on average 324+/-39 pg/ml (range: 23-1280, controls 10+/-2 pg/ml), ANP value was 144+/-17 pg/ml (range: 26-534, controls 15+/-1 pg/ml). BNP positively correlated with either end-diastolic or end-systolic RV volume in patients, less with LV systolic, and not with LV diastolic volume. Moreover, a significant negative correlation was observed between BNP and either LVEF or RVEF. Conversely, ANP showed a significant correlation only with end-systolic RV volume and with both RVEF and LVEF. When multivariate stepwise linear regression analysis was applied LVEF resulted the only independent predictor for ANP plasma values (R=0.591, P<0.001), while LVEF and RV end-diastolic volume for BNP (R=0.881, P<0.001, and R=0.881, P=0.035, respectively). Right heart overload contributes independently to plasma elevation of natriuretic peptides. RV involvement, which is known to independently worsen prognosis in patients with cardiomyopathy, might contribute to their established prognostic power, inducing compensatory secretion of plasma cardiac natriuretic hormones.

Clinical associations of total kidney volume: the Framingham Heart Study.

PubMed

Roseman, Daniel A; Hwang, Shih-Jen; Oyama-Manabe, Noriko; Chuang, Michael L; O'Donnell, Christopher J; Manning, Warren J; Fox, Caroline S

2017-08-01

Total kidney volume (TKV) is an imaging biomarker that may have diagnostic and prognostic utility. The relationships between kidney volume, renal function and cardiovascular disease (CVD) have not been characterized in a large community-dwelling population. This information is needed to advance the clinical application of TKV. We measured TKV in 1852 Framingham Heart Study participants (mean age 64.1 ± 9.2 years, 53% women) using magnetic resonance imaging. A healthy sample was used to define reference values. The associations between TKV, renal function and CVD risk factors were determined using multivariable logistic regression analysis. Overall, mean TKV was 278 ± 54 cm3 for women and 365 ± 66 cm3 for men. Risk factors for high TKV (>90% healthy referent size) were body surface area (BSA), diabetes, smoking and albuminuria, while age, female and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 were protective. Participants with high TKV had higher odds of diabetes [odds ratio (OR) 2.15, P < 0.001] and lower odds of eGFR <60 mL/min/1.73 m2 (OR 0.32, P = 0.007). Risk factors for low TKV (<10% healthy referent size) were age, female and eGFR <60 mL/min/1.73 m2, while BSA and diabetes were protective. Participants with low TKV had higher odds of eGFR <60 mL/min/1.73 m2 (OR 6.12, P < 0.001) and albuminuria (OR 1.56, P = 0.03). Low TKV is associated with markers of kidney damage including albuminuria and eGFR <60 mL/min/1.73 m2, while high TKV is associated with diabetes and decreased odds of eGFR <60 mL/min/1.73 m2. Prospective studies are needed to characterize the natural progression and clinical consequences of TKV. Published by Oxford University Press on behalf of ERA-EDTA 2016. This work is written by US Government employees and is in the public domain in the US.

Efficacy and safety of tolvaptan in heart failure patients with volume overload despite the standard treatment with conventional diuretics: a phase III, randomized, double-blind, placebo-controlled study (QUEST study).

PubMed

Matsuzaki, Masunori; Hori, Masatsugu; Izumi, Tohru; Fukunami, Masatake

2011-12-01

Diuretics are recommended to treat volume overload with heart failure (HF), however, they may cause serum electrolyte imbalance, limiting their use. Moreover, patients with advanced HF could poorly respond to these diuretics. In this study, we evaluated the efficacy and safety of Tolvaptan, a competitive vasopressin V2-receptor antagonist developed as a new drug to treat volume overload in HF patients. A phase III, multicenter, randomized, double-blind, placebo-controlled parallel study was performed to assess the efficacy and safety of tolvaptan in treating HF patients with volume overload despite the use of conventional diuretics. One hundred and ten patients were randomly assigned to receive either placebo or 15 mg/day tolvaptan for 7 consecutive days. Compared with placebo, tolvaptan administered for 7 days significantly reduced body weight and improved symptoms associated with volume overload. The safety profile of tolvaptan was considered acceptable for clinical use with minimal adverse effects. Tolvaptan reduced volume overload and improved congestive symptoms associated with HF by a potent water diuresis (aquaresis).

Image-Guided Radiotherapy for Left-Sided Breast Cancer Patients: Geometrical Uncertainty of the Heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Topolnjak, Rajko; Borst, Gerben R.; Nijkamp, Jasper

Purpose: To quantify the geometrical uncertainties for the heart during radiotherapy treatment of left-sided breast cancer patients and to determine and validate planning organ at risk volume (PRV) margins. Methods and Materials: Twenty-two patients treated in supine position in 28 fractions with regularly acquired cone-beam computed tomography (CBCT) scans for offline setup correction were included. Retrospectively, the CBCT scans were reconstructed into 10-phase respiration correlated four-dimensional scans. The heart was registered in each breathing phase to the planning CT scan to establish the respiratory heart motion during the CBCT scan ({sigma}{sub resp}). The average of the respiratory motion was calculatedmore » as the heart displacement error for a fraction. Subsequently, the systematic ({Sigma}), random ({sigma}), and total random ({sigma}{sub tot}={radical}({sigma}{sup 2}+{sigma}{sub resp}{sup 2})) errors of the heart position were calculated. Based on the errors a PRV margin for the heart was calculated to ensure that the maximum heart dose (D{sub max}) is not underestimated in at least 90% of the cases (M{sub heart} = 1.3{Sigma}-0.5{sigma}{sub tot}). All analysis were performed in left-right (LR), craniocaudal (CC), and anteroposterior (AP) directions with respect to both online and offline bony anatomy setup corrections. The PRV margin was validated by accumulating the dose to the heart based on the heart registrations and comparing the planned PRV D{sub max} to the accumulated heart D{sub max}. Results: For online setup correction, the cardiac geometrical uncertainties and PRV margins were N-Ary-Summation = 2.2/3.2/2.1 mm, {sigma} = 2.1/2.9/1.4 mm, and M{sub heart} = 1.6/2.3/1.3 mm for LR/CC/AP, respectively. For offline setup correction these were N-Ary-Summation = 2.4/3.7/2.2 mm, {sigma} = 2.9/4.1/2.7 mm, and M{sub heart} = 1.6/2.1/1.4 mm. Cardiac motion induced by breathing was {sigma}{sub resp} = 1.4/2.9/1.4 mm for LR/CC/AP. The PRV D{sub max} underestimated the accumulated heart D{sub max} for 9.1% patients using online and 13.6% patients using offline bony anatomy setup correction, which validated that PRV margin size was adequate. Conclusion: Considerable cardiac position variability relative to the bony anatomy was observed in breast cancer patients. A PRV margin can be used during treatment planning to take these uncertainties into account.« less

Evaluation of the acute and chronic safety of the biosense injection catheter system in porcine hearts.

PubMed

Kornowski, R; Fuchs, S; Tio, F O; Pierre, A; Epstein, S E; Leon, M B

1999-12-01

Direct myocardial injection of therapeutic agents has been explored as a new method for myocardial revascularization. The integration of a 3D electromechanical mapping catheter with a retractable injection needle should allow for intramyocardial injection to identified sites, obviating the need for open heart surgery. This study assessed the procedural safety and performance characteristics of a novel guided catheter-based transendocardial injection system. The electromagnetic guidance system was coupled with a retrievable 27G needle for left ventricular endocardial injection. Using this system, we injected, transendocardially, methylene-blue (MB) dye tracer at a volume of 0.1 or 0.2 ml per injection in eight normal pigs. Animals were sacrificed acutely, at 1, 3, and 7 days (two animal in each time). Three animals served as controls. The injections were followed by coronary angiography and echocardiogram to assess possible ventricular or coronary perforation and wall motion abnormalities. CK-MB levels were measured up to 24 hr following the procedure. The animals were sacrificed at the assigned time for gross and histopathology evaluation. A total of 101 injections were made in all regions of the heart except the apex and the mitral valve. No animal died as a result of the mapping or injection procedures. Vital signs did not change relative to baseline after the mapping and injection procedures. CK-MB values did not increase over time and there was no evidence of sustained arrhythmia or hemodynamic compromise. There was no evidence of left ventricular or coronary perforation, global or regional wall motion abnormalities, or hemopericardium. On histologic evaluation, the estimated volume of tissue staining was greater than the volume of the injected MB dye due to dispersion of the injectate in the interstitial and intracellular fluid compartments. It is concluded that using this magnetic guidance catheter-based navigational system, it is feasible and safe to perform the transendocardial injection procedure. Thus, if it is determined that direct intramyocardial injection of drugs is a valid therapeutic strategy, this approach offers a clear advantage over surgically based transepicardial injection procedures. Cathet. Cardiovasc. Intervent. 48:447-453, 1999. Copyright 1999 Wiley-Liss, Inc.

Mathematical Model Analysis of Heart-Arterial Interaction in Hypertension

DTIC Science & Technology

2001-10-25

conscious dogs with dilated cardiomyopathy ,” ! " # , vol. 260, pp. H1903-H1911, 1991. [7] P. Segers, N...with data measured in the isolated canine [14] or cat [15] heart, pumping into an artificial load or in the intact sheep [16] and human [7]. Left...instantaneous pressure-volume ratio of the canine left ventricle and effects of epinephrine and heart rate on the ratio,” , vol. 32, pp. 314

A novel cardiac MR chamber volume model for mechanical dyssynchrony assessment

NASA Astrophysics Data System (ADS)

Song, Ting; Fung, Maggie; Stainsby, Jeffrey A.; Hood, Maureen N.; Ho, Vincent B.

2009-02-01

A novel cardiac chamber volume model is proposed for the assessment of left ventricular mechanical dyssynchrony. The tool is potentially useful for assessment of regional cardiac function and identification of mechanical dyssynchrony on MRI. Dyssynchrony results typically from a contraction delay between one or more individual left ventricular segments, which in turn leads to inefficient ventricular function and ultimately heart failure. Cardiac resynchronization therapy has emerged as an electrical treatment of choice for heart failure patients with dyssynchrony. Prior MRI techniques have relied on assessments of actual cardiac wall changes either using standard cine MR images or specialized pulse sequences. In this abstract, we detail a semi-automated method that evaluates dyssynchrony based on segmental volumetric analysis of the left ventricular (LV) chamber as illustrated on standard cine MR images. Twelve sectors each were chosen for the basal and mid-ventricular slices and 8 sectors were chosen for apical slices for a total of 32 sectors. For each slice (i.e. basal, mid and apical), a systolic dyssynchrony index (SDI) was measured. SDI, a parameter used for 3D echocardiographic analysis of dyssynchrony, was defined as the corrected standard deviation of the time at which minimal volume is reached in each sector. The SDI measurement of a healthy volunteer was 3.54%. In a patient with acute myocardial infarction, the SDI measurements 10.98%, 16.57% and 1.41% for basal, mid-ventricular and apical LV slices, respectively. Based on published 3D echocardiogram reference threshold values, the patient's SDI corresponds to moderate basal dysfunction, severe mid-ventricular dysfunction, and normal apical LV function, which were confirmed on echocardiography. The LV chamber segmental volume analysis model and SDI is feasible using standard cine MR data and may provide more reliable assessment of patients with dyssynchrony especially if the LV myocardium is thin or if the MR images have spatial resolution insufficient for proper resolution of wall thickness-features problematic for dyssynchrony assessment using existing MR techniques.

Dosimetric evaluation of anatomical changes during treatment to identify criteria for adaptive radiotherapy in oesophageal cancer patients.

PubMed

Nyeng, Tine Bisballe; Nordsmark, Marianne; Hoffmann, Lone

2015-01-01

Some oesophageal cancer patients undergoing chemotherapy and concomitant radiotherapy (chemoRT) show large interfractional anatomical changes during treatment. These changes may modify the dose delivered to the target and organs at risk (OARs). The aim of the presenwt study was to investigate the dosimetric consequences of anatomical changes during treatment to obtain criteria for an adaptive RT decision support system. Twenty-nine patients were treated with chemoRT for oesophageal and gastro-oesophageal junction cancer and set up according to daily cone beam computed tomography (CBCTs) scans. All patients had an additional replanning CT scan at median fraction number 10 (9-14), which was deformably registered to the original planning CT. Gross tumour volumes (GTVs), clinical target volumes (CTVs) and OARs were transferred to the additional CT and corrected by an exwperienced physician. Treatment plans were recalculated and dose to targets and OARs was evaluated. Treatment was adapted if the volume receiving 95% of the prescribed dose (V95%) coverage of CTV decreased > 1% or planning target volume (PTV) decreased by > 3%. In total, nine adaptive events were observed: All nine were triggered by PTV V95% decrease > 3% [median 11% (5-41%)] and six of these were additionally triggered by CTV V95% decrease > 1% [median 5% (2-35%)]. The largest discrepancies were caused by interfractional baseline or amplitude shifts in diaphragm position (n = 5). Mediastinal (n = 6), oesophageal (n = 6) and bowel filling changes (n = 2) caused the remainder of the changes. For patients with dosimetric changes exceeding the adaptation limits, the discrepancies were confirmed by inspecting the daily CBCTs. In 31% of all patients, heart V30Gy increased more than 2% (maximum 5%). Only minor changes in lung dose or liver dose were seen. Target coverage throughout the course of chemoRT treatment is compromised in some patients due to interfractional anatomical changes. Dose to the heart may increase as well.

Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer

PubMed Central

Xu, Dandan; Li, Guowen; Li, Hongfei; Jia, Fei

2017-01-01

Abstract Background: Esophageal cancer (EC) is a common cancer with high mortality because of its rapid progression and poor prognosis. Radiotherapy is one of the most effective treatments for EC. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are 2 recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity, and reducing toxicity to normal organs. However, these advantages have not been demonstrated in the treatment of EC. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of EC in terms of dose–volume histograms and outcomes including survival and toxicity. Methods: A literature search was performed in PubMed, Embase, and the Cochrane library databases from their inceptions to Dec 30, 2016. Two authors independently assessed the included studies and extracted data. The average percent irradiated volumes of adjacent noncancerous organs were calculated and compared between IMRT and 3D-CRT. The odds ratio of overall survival (OS), and radiation pneumonitis and radiation esophagitis was also evaluated. Results: Totally 7 studies were included. Of them, 5 studies (80 patients) were included in the dosimetric comparison, 3 studies (871 patients) were included in the OS analysis, and 2 studies (205 patients) were included in the irradiation toxicity analysis. For lung in patients receiving doses ≥20 Gy and heart in patients receiving dose = 50 Gy, the average irradiated volumes of IMRT were less than those from 3D-CRT. IMRT resulted in a higher OS than 3D-CRT. However, no significant difference was observed in the incidence of radiation pneumonitis and radiation esophagitis between 2 radiotherapy techniques. Conclusion: Our data suggest that IMRT-delivered high radiation dose produces significantly less average percent volumes of irradiated lung and heart than 3D-CRT. IMRT is superior to 3D-CRT in the OS of EC while shows no benefit on radiation toxicity. PMID:28767597

Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer: A systematic review and meta-analysis.

PubMed

Xu, Dandan; Li, Guowen; Li, Hongfei; Jia, Fei

2017-08-01

Esophageal cancer (EC) is a common cancer with high mortality because of its rapid progression and poor prognosis. Radiotherapy is one of the most effective treatments for EC. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are 2 recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity, and reducing toxicity to normal organs. However, these advantages have not been demonstrated in the treatment of EC. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of EC in terms of dose-volume histograms and outcomes including survival and toxicity. A literature search was performed in PubMed, Embase, and the Cochrane library databases from their inceptions to Dec 30, 2016. Two authors independently assessed the included studies and extracted data. The average percent irradiated volumes of adjacent noncancerous organs were calculated and compared between IMRT and 3D-CRT. The odds ratio of overall survival (OS), and radiation pneumonitis and radiation esophagitis was also evaluated. Totally 7 studies were included. Of them, 5 studies (80 patients) were included in the dosimetric comparison, 3 studies (871 patients) were included in the OS analysis, and 2 studies (205 patients) were included in the irradiation toxicity analysis. For lung in patients receiving doses ≥20 Gy and heart in patients receiving dose = 50 Gy, the average irradiated volumes of IMRT were less than those from 3D-CRT. IMRT resulted in a higher OS than 3D-CRT. However, no significant difference was observed in the incidence of radiation pneumonitis and radiation esophagitis between 2 radiotherapy techniques. Our data suggest that IMRT-delivered high radiation dose produces significantly less average percent volumes of irradiated lung and heart than 3D-CRT. IMRT is superior to 3D-CRT in the OS of EC while shows no benefit on radiation toxicity.

Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

PubMed Central

Vieira, Stella S.; Lemes, Brunno; de T. C. de Carvalho, Paulo; N. de Lima, Rafael; S. Bocalini, Danilo; A. S. Junior, José; Arsa, Gisela; A. Casarin, Cezar; L. Andrade, Erinaldo; J. Serra, Andrey

2016-01-01

Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load. PMID:27347221

Relationship between shortening load, contractility, and myocardial energetics in intact dog.

PubMed

Dell'Italia, L J; Evanochko, W T; Blackwell, G G; Pearce, D J; Pohost, G M

1993-06-01

A canine model was developed to estimate left ventricular wall stress, volumes, contractility, and high-energy phosphate metabolites without the need for major surgery. A percutaneously inserted catheter-tip manometer was used to record high-fidelity left ventricular pressure while gradient echo cinemagnetic resonance (cine-MR) imaging alternated with in vivo 31P-nuclear magnetic resonance (NMR) spectroscopy during pharmacological maneuvers to increase cardiac work. Left ventricular circumferential wall stress, volumes, maximum rate of pressure development (dP/dtmax), and the ratio of phosphocreatine (PCr) to gamma-ATP (PCr/gamma-ATP) were recorded sequentially during control 1, dobutamine infusion, control 2, angiotensin infusion, and control 3 in five anesthetized, closed-chest dogs. PCr/gamma-ATP did not change significantly during controls 1-3, angiotensin, and dobutamine infusion. Left ventricular peak positive dP/dt (+dP/dtmax) increased significantly during dobutamine (3,338 +/- 831 mmHg/s, P < 0.001) but was unchanged during angiotensin (1,818 +/- 317 mmHg/s) and controls 1-3 (1,915 +/- 434 vs. 1,808 +/- 478 vs. 1,859 +/- 414 mmHg/s). However, dobutamine decreased the total systolic stress integral (area under the wall stress-time relationship) and end-diastolic and end-systolic volumes, whereas angiotensin increased these parameters compared with control conditions. The unchanged PCr/gamma-ATP is in accord with the results from other open-chest surface coil 31P-NMR experiments in the normal heart. Our assessment of left ventricular functional parameters provides new information that complements these more invasive studies in which heart rate-pressure product was measured during increases in cardiac work.(ABSTRACT TRUNCATED AT 250 WORDS)

Utility of Left Atrial Expansion Index and Stroke Volume in Management of Chronic Systolic Heart Failure.

PubMed

Hsiao, Shih-Hung; Lin, Shih-Kai; Chiou, Yi-Ran; Cheng, Chin-Chang; Hwang, Hwong-Ru; Chiou, Kuan-Rau

2018-06-01

Titration of evidence-based medications, important for treating heart failure (HF), is often underdosed by symptom-guided treatment. The aim of this study was to investigate, using echocardiographic parameters, stroke volume and left ventricular (LV) filling pressure to guide up-titration of medications, increasing prognostic benefits. A total of 765 patients with chronic HF and severely reduced LV ejection fractions (<35%), referred from 2008 to 2016, were prospectively studied. Echocardiographic guidance was performed in 149 patients. LV filling pressure was assessed by left atrial expansion index, and stroke volume was estimated from diameter and time-velocity integral in the LV outflow tract. Up-titration of evidence-based medications and adjustment for side effects or worsening clinical conditions according to those parameters were performed. Propensity score matching was used to match pairs of patients with (n = 110) or without (n = 110) echocardiographic guidance. End points were 4-year frequencies of HF hospitalization and all-cause mortality. During a mean follow-up time of 4.1 years, rates of adverse events were 58 (52.7%) with no echocardiographic guidance and 36 (32.7%) with echocardiographic guidance (P < .0001). Echocardiography provided effective guidance to reduce prescribing frequency and dose of diuretics and to promote evidence-based medication prescription. It reduced HF rehospitalization and all-cause mortality. By multivariate analysis, prognostic improvement was associated with up-titration of medications with echocardiographic guidance. There was a statistically significant difference in long-term prognosis between propensity score-matched pairs of patients with chronic severe HF with and without echocardiographic guidance. These findings need further validation in large prospective clinical trials. Copyright © 2018 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Use of the Frank-Starling mechanism during exercise is linked to exercise-induced changes in arterial load

PubMed Central

Chantler, Paul D.; Melenovsky, Vojtech; Schulman, Steven P.; Gerstenblith, Gary; Becker, Lewis C.; Ferrucci, Luigi; Fleg, Jerome L.; Najjar, Samer S.

2012-01-01

Effective arterial elastance(EA) is a measure of the net arterial load imposed on the heart that integrates the effects of heart rate(HR), peripheral vascular resistance(PVR), and total arterial compliance(TAC) and is a modulator of cardiac performance. To what extent the change in EA during exercise impacts on cardiac performance and aerobic capacity is unknown. We examined EA and its relationship with cardiovascular performance in 352 healthy subjects. Subjects underwent rest and exercise gated scans to measure cardiac volumes and to derive EA[end-systolic pressure/stroke volume index(SV)], PVR[MAP/(SV*HR)], and TAC(SV/pulse pressure). EA varied with exercise intensity: the ΔEA between rest and peak exercise along with its determinants, differed among individuals and ranged from −44% to +149%, and was independent of age and sex. Individuals were separated into 3 groups based on their ΔEAI. Individuals with the largest increase in ΔEA(group 3;ΔEA≥0.98 mmHg.m2/ml) had the smallest reduction in PVR, the greatest reduction in TAC and a similar increase in HR vs. group 1(ΔEA<0.22 mmHg.m2/ml). Furthermore, group 3 had a reduction in end-diastolic volume, and a blunted increase in SV(80%), and cardiac output(27%), during exercise vs. group 1. Despite limitations in the Frank-Starling mechanism and cardiac function, peak aerobic capacity did not differ by group because arterial-venous oxygen difference was greater in group 3 vs. 1. Thus the change in arterial load during exercise has important effects on the Frank-Starling mechanism and cardiac performance but not on exercise capacity. These findings provide interesting insights into the dynamic cardiovascular alterations during exercise. PMID:22003052

Association of intraventricular mechanical dyssynchrony with response to cardiac resynchronization therapy in heart failure patients with a narrow QRS complex

PubMed Central

van Bommel, Rutger J.; Tanaka, Hidekazu; Delgado, Victoria; Bertini, Matteo; Borleffs, Carel Jan Willem; Ajmone Marsan, Nina; Holzmeister, Johannes; Ruschitzka, Frank; Schalij, Martin J.; Bax, Jeroen J.; Gorcsan, John

2010-01-01

Aims Current criteria for cardiac resynchronization therapy (CRT) are restricted to patients with a wide QRS complex (>120 ms). Overall, only 30% of heart failure patients demonstrate a wide QRS complex, leaving the majority of heart failure patients without this treatment option. However, patients with a narrow QRS complex exhibit left ventricular (LV) mechanical dyssynchrony, as assessed with echocardiography. To further elucidate the possible beneficial effect of CRT in heart failure patients with a narrow QRS complex, this two-centre, non-randomized observational study focused on different echocardiographic parameters of LV mechanical dyssynchrony reflecting atrioventricular, interventricular and intraventricular dyssynchrony, and the response to CRT in these patients. Methods and results A total of 123 consecutive heart failure patients with a narrow QRS complex (<120 ms) undergoing CRT was included at two centres. Several widely accepted measures of mechanical dyssynchrony were evaluated: LV filling ratio (LVFT/RR), LV pre-ejection time (LPEI), interventricular mechanical dyssynchrony (IVMD), opposing wall delay (OWD), and anteroseptal posterior wall delay with speckle tracking (ASPWD). Response to CRT was defined as a reduction ≥15% in left ventricular end-systolic volume at 6 months follow-up. Measures of dyssynchrony can frequently be observed in patients with a narrow QRS complex. Nonetheless, for LVFT/RR, LPEI, and IVMD, presence of predefined significant dyssynchrony is <20%. Significant intraventricular dyssynchrony is more widely observed in these patients. With receiver operator characteristic curve analyses, both OWD and ASPWD demonstrated usefulness in predicting response to CRT in narrow QRS patients with a cut-off value of 75 and 107 ms, respectively. Conclusion Mechanical dyssynchrony can be widely observed in heart failure patients with a narrow QRS complex. In particular, intraventricular measures of mechanical dyssynchrony may be useful in predicting LV reverse remodelling at 6 months follow-up in heart failure patients with a narrow QRS complex, but with more stringent cut-off values than currently used in ‘wide’ QRS patients. PMID:20864484

Validation of a defibrillation lead ventricular volume measurement compared to three-dimensional echocardiography.

PubMed

Haines, David E; Wong, Wilson; Canby, Robert; Jewell, Coty; Houmsse, Mahmoud; Pederson, David; Sugeng, Lissa; Porterfield, John; Kottam, Anil; Pearce, John; Valvano, Jon; Michalek, Joel; Trevino, Aron; Sagar, Sandeep; Feldman, Marc D

2017-10-01

There is increasing evidence that using frequent invasive measures of pressure in patients with heart failure results in improved outcomes compared to traditional measures. Admittance, a measure of volume derived from preexisting defibrillation leads, is proposed as a new technique to monitor cardiac hemodynamics in patients with an implantable defibrillator. The purpose of this study was to evaluate the accuracy of a new ventricular volume sensor (VVS, CardioVol) compared with 3-dimenssional echocardiography (echo) in patients with an implantable defibrillator. Twenty-two patients referred for generator replacement had their defibrillation lead attached to VVS to determine the level of agreement to a volume measurement standard (echo). Two opposite hemodynamic challenges were sequentially applied to the heart (overdrive pacing and dobutamine administration) to determine whether real changes in hemodynamics could be reliably and repeatedly assessed with VVS. Equivalence of end-diastolic volume (EDV) and stroke volume (SV) determined by both methods was also assessed. EDV and SV were compared using VVS and echo. VVS tracked expected physiologic trends. EDV was modulated -10% by overdrive pacing (14 mL). SV was modulated -13.7% during overdrive pacing (-6 mL) and increased over baseline +14.6% (+8 mL) with dobutamine. VVS and echo mean EDVs were found statistically equivalent, with margin of equivalence 13.8 mL (P <.05). Likewise, mean SVs were found statistically equivalent with margin of equivalence 15.8 mL (P <.05). VVS provides an accurate method for ventricular volume assessment using chronically implanted defibrillator leads and is statistically equivalent to echo determination of mean EDV and SV. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Characterizing Heart Failure in the Ventricular Volume Domain

PubMed Central

Kerkhof, Peter LM

2015-01-01

Heart failure (HF) may be accompanied by considerable alterations of left ventricular (LV) volume, depending on the particular phenotype. Two major types of HF have been identified, although heterogeneity within each category may be considerable. All variants of HF show substantially elevated LV filling pressures, which tend to induce changes in LV size and shape. Yet, one type of HF is characterized by near-normal values for LV end-diastolic volume (EDV) and even a smaller end-systolic volume (ESV) than in matched groups of persons without cardiac disease. Furthermore, accumulating evidence indicates that, both in terms of shape and size, in men and women, the heart reacts differently to adaptive stimuli as well as to certain pharmacological interventions. Adjustments of ESV and EDV such as in HF patients are associated with (reverse) remodeling mechanisms. Therefore, it is logical to analyze HF subtypes in a graphical representation that relates ESV to EDV. Following this route, one may expect that the two major phenotypes of HF are identified as distinct entities localized in different areas of the LV volume domain. The precise coordinates of this position imply unique characteristics in terms of the actual operating point for LV volume regulation. Evidently, ejection fraction (EF; equal to 1 minus the ratio of ESV and EDV) carries little information within the LV volume representation. Thus far, classification of HF is based on information regarding EF combined with EDV. Our analysis shows that ESV in the two HF groups follows different patterns in dependency of EDV. This observation suggests that a superior HF classification system should primarily be founded on information embodied by ESV. PMID:25780344

Safe Hydration Volume to Prevent Contrast-induced Acute Kidney Injury and Worsening Heart Failure in Patients With Heart Failure and Preserved Ejection Fraction After Cardiac Catheterization.

PubMed

Bei, Wei-Jie; Wang, Kun; Li, Hua-Long; Lin, Kai-Yang; Guo, Xiao-Sheng; Chen, Shi-Qun; Liu, Yong; Yi, Shi-Xin; Luo, De-Mou; Chen, Ji-Yan; Tan, Ning

2017-09-01

Few studies have investigated the efficacy and safety of hydration to prevent contrast-induced acute kidney injury (CI-AKI) and worsening heart failure (WHF) after cardiac catheterization in heart failure and preserved ejection fraction (HFpEF; HF and EF ≥50%) patients. We recruited 1206 patients with HFpEF undergoing cardiac catheterization with periprocedural hydration volume/weight (HV/W) ratio data and investigated the relationship between hydration volumes and risk of CI-AKI and WHF. Incidence of CI-AKI was not significantly reduced in individuals with higher HV/W [quartile (Q) 1, Q2, Q3, and Q4: 9.7%, 10.2%, 12.7%, and 12.2%, respectively; P = 0.219]. Multivariate analysis indicated that higher HV/W ratios were not associated with decreased CI-AKI risks [Q2 vs. Q1: odds ratio (OR), 0.95; Q3 vs. Q1: OR, 1.07; Q4 vs. Q1: OR, 0.92; all P > 0.05]. According to multivariate analysis, higher HV/W significantly increased the WHF risk (Q4 vs. Q1: adjusted OR, 8.13 and 95% confidence interval, 1.03-64.02; P = 0.047). CI-AKI and WHF were associated with a significantly increased risk of long-term mortality (mean follow-up, 2.33 years). For HFpEF patients, an excessively high hydration volume might not be associated with lower risk of CI-AKI but may increase the risk of postprocedure WHF.

Combined heart-kidney transplantation after total artificial heart insertion.

PubMed

Ruzza, A; Czer, L S C; Ihnken, K A; Sasevich, M; Trento, A; Ramzy, D; Esmailian, F; Moriguchi, J; Kobashigawa, J; Arabia, F

2015-01-01

We present the first single-center report of 2 consecutive cases of combined heart and kidney transplantation after insertion of a total artificial heart (TAH). Both patients had advanced heart failure and developed dialysis-dependent renal failure after implantation of the TAH. The 2 patients underwent successful heart and kidney transplantation, with restoration of normal heart and kidney function. On the basis of this limited experience, we consider TAH a safe and feasible option for bridging carefully selected patients with heart and kidney failure to combined heart and kidney transplantation. Recent FDA approval of the Freedom driver may allow outpatient management at substantial cost savings. The TAH, by virtue of its capability of providing pulsatile flow at 6 to 10 L/min, may be the mechanical circulatory support device most likely to recover patients with marginal renal function and advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

Balancing tissue perfusion demands: cardiovascular dynamics of Cancer magister during exposure to low salinity and hypoxia.

PubMed

McGaw, Iain J; McMahon, Brian R

2003-01-01

Decapod crustaceans inhabit aquatic environments that are frequently subjected to changes in salinity and oxygen content. The physiological responses of decapod crustaceans to either salinity or hypoxia are well documented; however, there are many fewer reports on the physiological responses during exposure to these parameters in combination. We investigated the effects of simultaneous and sequential combinations of low salinity and hypoxia on the cardiovascular physiology of the Dungeness crab, Cancer magister. Heart rate, as well as haemolymph flow rates through the anterolateral, hepatic, sternal and posterior arteries were measured using a pulsed-Doppler flowmeter. Summation of flows allowed calculation of cardiac output and division of this by heart rate yielded stroke volume. When hypoxia and low salinity were encountered simultaneously, the observed changes in cardiac properties tended to be a mix of both factors. Hypoxia caused a bradycardia, whereas exposure to low salinity was associated with a tachycardia. However, the hypoxic conditions had the dominant effect on heart rate. Although hypoxia caused an increase in stroke volume of the heart, the low salinity had a more pronounced effect, causing an overall decrease in stroke volume. The patterns of haemolymph flow through the arterial system also varied when hypoxia and low salinity were offered together. The resulting responses were a mix of those resulting from exposure to either parameter alone. When low salinity and hypoxia were offered sequentially, the parameter experienced first tended to have the dominant effect on cardiac function and haemolymph flows. Low salinity exposure was associated with an increase in heart rate, a decrease in stroke volume and cardiac output, and a concomitant decrease in haemolymph flow rates. Subsequent exposure to hypoxic conditions caused a slight decrease in rate, but other cardiovascular variables were largely unaffected. In contrast, when low salinity followed acclimation to hypoxic conditions, apart from an increased heart rate, there were no other cardiovascular changes associated with the low salinity episode. The implications of these changes in cardiovascular dynamics are discussed in relation to physiological mechanisms and the ecology of decapod crustaceans, in hypoxic or low salinity environments. Copyright 2003, Wiley-Liss, Inc.

The total artificial heart for biventricular heart failure and beyond.

PubMed

Kasirajan, Vigneshwar; Tang, Daniel G; Katlaps, Gundars J; Shah, Keyur B

2012-05-01

Treatment options for late-stage biventricular heart failure are limited but include medical therapy with intravenous inotropes, biventricular assist devices (Bi-VADs) and the total artificial heart (TAH). In this manuscript, we review the indications, surgical techniques and outcomes for the TAH. The TAH offers biventricular replacement, rather than 'assistance', as the device is placed orthotopically after excision of the entire ventricular myocardium and all four native valves. In contrast to patients with Bi-VADs, patients with the TAH have no postoperative inotrope requirements, arrhythmias or inflow/outflow cannulae-related complications. Additionally, patients participate in rehabilitation early after device placement and the development of a portable drive may facilitate hospital discharge in the USA. Furthermore, total heart replacement may be ideal for heart failure associated with unique anatomical and mechanical complications. The TAH is an effective therapeutic option for the treatment of patients dying of heart failure who may not be suitable candidates for left ventricular assist devices.

Sleep Wakefulness Determinations From Heart Rate Data. Volume III.

DTIC Science & Technology

1977-05-31

differentiating It from states such as coma, trance, and anesthesia . The study of the phenomena of sleep has occupied researchers for many years...pressure and heart rate in the rabbit during animal hypnosis . Electroencephalog. Clln. Neurophslol., 37:231-237, 1974. 19. Clausen, J., Sersen, E.A

Spacelab

NASA Image and Video Library

1995-06-01

Spacelab Life Science -1 (SLS-1) was the first Spacelab mission dedicated solely to life sciences. The main purpose of the SLS-1 mission was to study the mechanisms, magnitudes, and time courses of certain physiological changes that occur during space flight, to investigate the consequences of the body's adaptation to microgravity and readjustment to Earth's gravity, and bring the benefits back home to Earth. The mission was designed to explore the responses of the heart, lungs, blood vessels, kidneys, and hormone-secreting glands to microgravity and related body fluid shifts; examine the causes of space motion sickness; and study changes in the muscles, bones, and cells. This photograph shows astronaut Rhea Seddon conducting an inflight study of the Cardiovascular Deconditioning experiment by breathing into the cardiovascular rebreathing unit. This experiment focused on the deconditioning of the heart and lungs and changes in cardiopulmonary function that occur upon return to Earth. By using noninvasive techniques of prolonged expiration and rebreathing, investigators can determine the amount of blood pumped out of the heart (cardiac output), the ease with which blood flows through all the vessels (total peripheral resistance), oxygen used and carbon dioxide released by the body, and lung function and volume changes. SLS-1 was launched aboard the Space Shuttle Orbiter Columbia (STS-40) on June 5, 1995.

Spacelab Life Science-1 Mission Onboard Photograph

NASA Technical Reports Server (NTRS)

1995-01-01

Spacelab Life Science -1 (SLS-1) was the first Spacelab mission dedicated solely to life sciences. The main purpose of the SLS-1 mission was to study the mechanisms, magnitudes, and time courses of certain physiological changes that occur during space flight, to investigate the consequences of the body's adaptation to microgravity and readjustment to Earth's gravity, and bring the benefits back home to Earth. The mission was designed to explore the responses of the heart, lungs, blood vessels, kidneys, and hormone-secreting glands to microgravity and related body fluid shifts; examine the causes of space motion sickness; and study changes in the muscles, bones, and cells. This photograph shows astronaut Rhea Seddon conducting an inflight study of the Cardiovascular Deconditioning experiment by breathing into the cardiovascular rebreathing unit. This experiment focused on the deconditioning of the heart and lungs and changes in cardiopulmonary function that occur upon return to Earth. By using noninvasive techniques of prolonged expiration and rebreathing, investigators can determine the amount of blood pumped out of the heart (cardiac output), the ease with which blood flows through all the vessels (total peripheral resistance), oxygen used and carbon dioxide released by the body, and lung function and volume changes. SLS-1 was launched aboard the Space Shuttle Orbiter Columbia (STS-40) on June 5, 1995.

A randomized controlled clinical trial to evaluate blood pressure changes in patients undergoing extraction under local anesthesia with vasopressor use.

PubMed

Uzeda, Marcelo José; Moura, Brenda; Louro, Rafael Seabra; da Silva, Licínio Esmeraldo; Calasans-Maia, Mônica Diuana

2014-05-01

The control of hypertensive patients' blood pressure and heart rate using vasoconstrictors during surgical procedures under anesthesia is still a major concern in everyday surgical practice. This clinical trial aimed to evaluate the variation of blood pressure and heart rate in nonhypertensive and controlled hypertensive voluntary subjects undergoing oral surgery under local anesthesia with lidocaine hydrochloride and epinephrine at 1:100,000 (Alphacaine; DFL, Brazil), performed in the Oral Surgery Department, Dentistry School, Fluminense Federal University. In total, 25 voluntary subjects were divided into 2 groups: nonhypertensive (n = 15) and controlled hypertensives (n = 10). Blood pressure and heart rate were measured at 4 different times: T0, in the waiting room; T1, after placement of the surgical drapes; T2, 10 minutes after anesthesia injection; and T3, at the end of the surgical procedure. A statistically significant difference (P < 0.05) between the groups was found at times T0 and T2 for the systolic pressure but only at time T0 for the diastolic pressure. The assessment of the heart rate of both groups showed a statistically significant difference (P < 0.05) at time T1. An analysis of the employed anesthetic volume indicated no statistically significant difference (P > 0.05) between the amount administered to nonhypertensive and hypertensive subjects. It was concluded that the local anesthetics studied could safely be used in controlled hypertensive and nonhypertensive patients in compliance with the maximum recommended doses.

[Experts consensus on the management of the right heart function in critically ill patients].

PubMed

Wang, X T; Liu, D W; Zhang, H M; Long, Y; Guan, X D; Qiu, H B; Yu, K J; Yan, J; Zhao, H; Tang, Y Q; Ding, X; Ma, X C; Du, W; Kang, Y; Tang, B; Ai, Y H; He, H W; Chen, D C; Chen, H; Chai, W Z; Zhou, X; Cui, N; Wang, H; Rui, X; Hu, Z J; Li, J G; Xu, Y; Yang, Y; Ouyan, B; Lin, H Y; Li, Y M; Wan, X Y; Yang, R L; Qin, Y Z; Chao, Y G; Xie, Z Y; Sun, R H; He, Z Y; Wang, D F; Huang, Q Q; Jiang, D P; Cao, X Y; Yu, R G; Wang, X; Chen, X K; Wu, J F; Zhang, L N; Yin, M G; Liu, L X; Li, S W; Chen, Z J; Luo, Z

2017-12-01

To establish the experts consensus on the right heart function management in critically ill patients. The panel of consensus was composed of 30 experts in critical care medicine who are all members of Critical Hemodynamic Therapy Collaboration Group (CHTC Group). Each statement was assessed based on the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) principle. Then the Delphi method was adopted by 52 experts to reassess all the statements. (1) Right heart function is prone to be affected in critically illness, which will result in a auto-exaggerated vicious cycle. (2) Right heart function management is a key step of the hemodynamic therapy in critically ill patients. (3) Fluid resuscitation means the process of fluid therapy through rapid adjustment of intravascular volume aiming to improve tissue perfusion. Reversed fluid resuscitation means reducing volume. (4) The right ventricle afterload should be taken into consideration when using stroke volume variation (SVV) or pulse pressure variation (PPV) to assess fluid responsiveness.(5)Volume overload alone could lead to septal displacement and damage the diastolic function of the left ventricle. (6) The Starling curve of the right ventricle is not the same as the one applied to the left ventricle,the judgement of the different states for the right ventricle is the key of volume management. (7) The alteration of right heart function has its own characteristics, volume assessment and adjustment is an important part of the treatment of right ventricular dysfunction (8) Right ventricular enlargement is the prerequisite for increased cardiac output during reversed fluid resuscitation; Nonetheless, right heart enlargement does not mandate reversed fluid resuscitation.(9)Increased pulmonary vascular resistance induced by a variety of factors could affect right heart function by obstructing the blood flow. (10) When pulmonary hypertension was detected in clinical scenario, the differentiation of critical care-related pulmonary hypertension should be a priority. (11) Attention should be paid to the change of right heart function before and after implementation of mechanical ventilation and adjustment of ventilator parameter. (12) The pulmonary arterial pressure should be monitored timingly when dealing with critical care-related pulmonary hypertension accompanied with circulatory failure.(13) The elevation of pulmonary aterial pressure should be taken into account in critical patients with acute right heart dysfunction. (14) Prone position ventilation is an important measure to reduce pulmonary vascular resistance when treating acute respiratory distress syndrome patients accompanied with acute cor pulmonale. (15) Attention should be paid to right ventricle-pulmonary artery coupling during the management of right heart function. (16) Right ventricular diastolic function is more prone to be affected in critically ill patients, the application of critical ultrasound is more conducive to quantitative assessment of right ventricular diastolic function. (17) As one of the parameters to assess the filling pressure of right heart, central venous pressure can be used to assess right heart diastolic function. (18). The early and prominent manifestation of non-focal cardiac tamponade is right ventricular diastolic involvement, the elevated right atrial pressure should be noticed. (19) The effect of increased intrathoracic pressure on right heart diastolic function should be valued. (20) Ttricuspid annular plane systolic excursion (TAPSE) is an important parameter that reflects right ventricular systolic function, and it is recommended as a general indicator of critically ill patient. (21) Circulation management with right heart protection as the core strategy is the key point of the treatment of acute respiratory distress syndrome. (22) Right heart function involvement after cardiac surgery is very common and should be highly valued. (23) Right ventricular dysfunction should not be considered as a routine excuse for maintaining higher central venous pressure. (24) When left ventricular dilation, attention should be paid to the effect of left ventricle on right ventricular diastolic function. (25) The impact of left ventricular function should be excluded when the contractility of the right ventricle is decreased. (26) When the right heart load increases acutely, the shunt between the left and right heart should be monitored. (27) Attention should be paid to the increase of central venous pressure caused by right ventricular dysfunction and its influence on microcirculation blood flow. (28) When the vasoactive drugs was used to reduce the pressure of pulmonary circulation, different effects on pulmonary and systemic circulation should be evaluated. (29) Right atrial pressure is an important factor affecting venous return. Attention should be paid to the influence of the pressure composition of the right atrium on the venous return. (30) Attention should be paid to the role of the right ventricle in the acute pulmonary edema. (31) Monitoring the difference between the mean systemic filling pressure and the right atrial pressure is helpful to determine whether the infusion increases the venous return. (32) Venous return resistance is often considered to be a insignificant factor that affects venous return, but attention should be paid to the effect of the specific pathophysiological status, such as intrathoracic hypertension, intra-abdominal hypertension and so on. Consensus can promote right heart function management in critically ill patients, optimize hemodynamic therapy, and even affect prognosis.

Cardiac magnetic resonance imaging in heart failure: where the alphabet begins!

PubMed

Aljizeeri, Ahmed; Sulaiman, Abdulbaset; Alhulaimi, Naji; Alsaileek, Ahmed; Al-Mallah, Mouaz H

2017-07-01

Cardiac Magnetic Resonance Imaging has become a cornerstone in the evaluation of heart failure. It provides a comprehensive evaluation by answering all the pertinent clinical questions across the full pathological spectrum of heart failure. Nowadays, CMR is considered the gold standard in evaluation of ventricular volumes, wall motion and systolic function. Through its unique ability of tissue characterization, it provides incremental diagnostic and prognostic information and thus has emerged as a comprehensive imaging modality in heart failure. This review outlines the role of main conventional CMR sequences in the evaluation of heart failure and their impact in the management and prognosis.

Dynamic Energy Loss Characteristics in the Native Aortic Valve

NASA Astrophysics Data System (ADS)

Hwai Yap, Choon; Dasi, Laksmi P.; Yoganathan, Ajit P.

2009-11-01

Aortic Valve (AV) stenosis if untreated leads to heart failure. From a mechanics standpoint, heart failure implies failure to generate sufficient mechanical power to overcome energy losses in the circulation. Thus energy efficiency-based measures are direct measures of AV disease severity, which unfortunately is not used in current clinical measures of stenosis severity. We present an analysis of the dynamic rate of energy dissipation through the AV from direct high temporal resolution measurements of flow and pressure drop across the AV in a pulsatile left heart setup. Porcine AV was used and measurements at various conditions were acquired: varying stroke volumes; heart rates; and stenosis levels. Energy dissipation waveform has a distinctive pattern of being skewed towards late systole, attributed to the explosive growth of flow instabilities from adverse pressure gradient. Increasing heart rate and stroke volume increases energy dissipation, but does not alter the normalized shape of the dissipation temporal profile. Stenosis increases energy dissipation and also alters the normalized shape of dissipation waveform with significantly more losses during late acceleration phase. Since stenosis produces a departure from the signature dissipation waveform shape, dynamic energy dissipation analysis can be extended into a clinical tool for AV evaluation.

Human sinus arrhythmia as an index of vagal cardiac outflow

NASA Technical Reports Server (NTRS)

Eckberg, D. L.

1983-01-01

The human central vagal mechanisms were investigated by measuring the intervals between heartbeats during controlled breathing (at breathing intervals of 2.5-10 s and nominal tidal volumes of 1000 and 1500 ml) in six young men and women. It was found that as the breathing interval increased, the longest heart periods became longer, the shortest heart periods became shorter, and the peak-valley P-P intervals increased asymptotically. Peak-valley intervals also increased in proportion to tidal volume, although this influence was small. The phase angles between heart period changes and respiration were found to vary as linear functions of breathing interval. Heart period shortening began in inspiration at short breathing intervals and in expiration at long breathing intervals, while heart period lengthening began in early expiration at all breathing intervals studied. It is concluded that a close relationship exists between variations of respiratory depth and interval and the quantity, periodicity, and timing of vagal cardiac outflow in conscious humans. The results indicate that at usual breathing rates, phasic respiration-related changes of vagal motoneuron activity begin in expiration, progress slowly, and are incompletely expressed at fast breathing ratges.

Perflurooctanoic Acid Induces Developmental Cardiotoxicity in ...

EPA Pesticide Factsheets

Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPAR_). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that d

Heart Dose Is an Independent Dosimetric Predictor of Overall Survival in Locally Advanced Non-Small Cell Lung Cancer.

PubMed

Speirs, Christina K; DeWees, Todd A; Rehman, Sana; Molotievschi, Alerson; Velez, Maria A; Mullen, Daniel; Fergus, Sandra; Trovo, Marco; Bradley, Jeffrey D; Robinson, Cliff G

2017-02-01

In the randomized trial of standard- versus high-dose chemoradiotherapy for locally advanced (LA) NSCLC (Radiation Therapy Oncology Group 0617), overall survival (OS) was worse in the high-dose arm. Although heart dose was suggested as a contributing factor, actionable parameters have not been established. We present an analysis of clinical and dosimetric parameters affecting OS in this patient population, focusing on heart dose. Clinical data were collected on 416 patients with LA NSCLC treated at a single institution, with a subset of 333 available treatment plans recontoured using Radiation Therapy Oncology Group 0617 normal tissue guidelines. Toxicity and dosimetry data were analyzed for 322 patients; multivariate analysis was performed on 251 patients. Dosimetric parameters of radiation to tumor and organs at risk were analyzed with clinical data pertaining to OS, disease-free survival, and toxicity. Patients were treated with radiation therapy to prescribed doses of 50.0 to 84.9 Gy (median 66.0 Gy). Median follow-up was 14.5 months. Median OS was 16.8 months. The 1- and 2-year OS rates were 61.4% and 38.8%, respectively. On multivariate analysis, factors independently associated with worse OS were increasing heart V 50 (volume receiving ≥50 Gy), heart volume, lung V 5 (proportion of the lung structure [excluding the target volume]) receiving at least 5 Gy), bilateral mediastinal lymph node involvement, and lack of concurrent chemotherapy. When stratified by heart V 50 less than 25% versus 25% or greater, the 1-year OS rates were 70.2% versus 46.8% and the 2-year OS rates were 45.9% versus 26.7% (p < 0.0001). Median heart V 50 was significantly higher (20.8% versus 13.9%, p < 0.0001) for patients with cardiac toxicity with a Common Terminology Criteria for Adverse Events grade of 1 or higher. Heart dose is associated with OS and cardiac toxicity for patients with LA NSCLC treated with chemoradiotherapy. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

SU-E-J-244: Development and Validation of a Knowledge Based Planning Model for External Beam Radiation Therapy of Locally Advanced Non-Small Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Z; Kennedy, A; Larsen, E

2015-06-15

Purpose: The study aims to develop and validate a knowledge based planning (KBP) model for external beam radiation therapy of locally advanced non-small cell lung cancer (LA-NSCLC). Methods: RapidPlan™ technology was used to develop a lung KBP model. Plans from 65 patients with LA-NSCLC were used to train the model. 25 patients were treated with VMAT, and the other patients were treated with IMRT. Organs-at-risk (OARs) included right lung, left lung, heart, esophagus, and spinal cord. DVH and geometric distribution DVH were extracted from the treated plans. The model was trained using principal component analysis and step-wise multiple regression. Boxmore » plot and regression plot tools were used to identify geometric outliers and dosimetry outliers and help fine-tune the model. The validation was performed by (a) comparing predicted DVH boundaries to actual DVHs of 63 patients and (b) using an independent set of treatment planning data. Results: 63 out of 65 plans were included in the final KBP model with PTV volume ranging from 102.5cc to 1450.2cc. Total treatment dose prescription varied from 50Gy to 70Gy based on institutional guidelines. One patient was excluded due to geometric outlier where 2.18cc of spinal cord was included in PTV. The other patient was excluded due to dosimetric outlier where the dose sparing to spinal cord was heavily enforced in the clinical plan. Target volume, OAR volume, OAR overlap volume percentage to target, and OAR out-of-field volume were included in the trained model. Lungs and heart had two principal component scores of GEDVH, whereas spinal cord and esophagus had three in the final model. Predicted DVH band (mean ±1 standard deviation) represented 66.2±3.6% of all DVHs. Conclusion: A KBP model was developed and validated for radiotherapy of LA-NSCLC in a commercial treatment planning system. The clinical implementation may improve the consistency of IMRT/VMAT planning.« less

Congenital heart defects in cats: A retrospective study of 162 cats (1996-2013).

PubMed

Tidholm, Anna; Ljungvall, Ingrid; Michal, Jenny; Häggström, Jens; Höglund, Katja

2015-12-01

To study the prevalence and distribution of congenital heart defects in cats presented at two referral centers in Sweden between 1996 and 2013. 162 client-owned cats with congenital heart defects. Case records of cats diagnosed with congenital heart disease were reviewed retrospectively. The overall prevalence of congenital heart disease was 0.2% of the total number of patient cats, and 8% of cats diagnosed with heart disease. A total of 182 heart defects were identified as 16 cats were diagnosed with more than one defect. Ventricular septal defect (VSD) was most prevalent, found in 50% of cats, followed by tricuspid valve dysplasia (11%), pulmonic stenosis (10%), atrial septal defect (10%), aortic stenosis (9%), mitral valve dysplasia (9%), tetralogy of Fallot (5%), patent ductus arteriosus (3%), common atrioventricular canal (2%), and the following defects that each accounted for 0.6% of cats: double chamber right ventricle, double outlet right ventricle, endocardial fibroelastosis, dextroposition of the aorta, persistent right aortic arch, and pulmonary atresia. The prevalence of congenital heart disease was 0.2% of the total number of patient cats, and 8% of cats diagnosed with heart disease. Ventricular septal defect was the most common congenital heart defect in this study. Copyright © 2014 Elsevier B.V. All rights reserved.

Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

PubMed Central

Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

2015-01-01

Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge. PMID:25973923

Measuring hospital performance in congenital heart surgery: Administrative vs. clinical registry data

PubMed Central

Pasquali, Sara K.; He, Xia; Jacobs, Jeffrey P.; Jacobs, Marshall L.; Gaies, Michael G.; Shah, Samir S.; Hall, Matthew; Gaynor, J. William; Peterson, Eric D.; Mayer, John E.; Hirsch-Romano, Jennifer C.

2015-01-01

Background In congenital heart surgery, hospital performance has historically been assessed using widely available administrative datasets. Recent studies have demonstrated inaccuracies in case ascertainment (coding and inclusion of eligible cases) in administrative vs. clinical registry data, however it is unclear whether this impacts assessment of performance on a hospital-level. Methods Merged data from the Society of Thoracic Surgeons (STS) Database (clinical registry), and Pediatric Health Information Systems Database (administrative dataset) on 46,056 children undergoing heart surgery (2006–2010) were utilized to evaluate in-hospital mortality for 33 hospitals based on their administrative vs. registry data. Standard methods to identify/classify cases were used: Risk Adjustment in Congenital Heart Surgery (RACHS-1) in the administrative data, and STS–European Association for Cardiothoracic Surgery (STAT) methodology in the registry. Results Median hospital surgical volume based on the registry data was 269 cases/yr; mortality was 2.9%. Hospital volumes and mortality rates based on the administrative data were on average 10.7% and 4.7% lower, respectively, although this varied widely across hospitals. Hospital rankings for mortality based on the administrative vs. registry data differed by ≥ 5 rank-positions for 24% of hospitals, with a change in mortality tertile classification (high, middle, or low mortality) for 18%, and change in statistical outlier classification for 12%. Higher volume/complexity hospitals were most impacted. Agency for Healthcare Quality and Research methods in the administrative data yielded similar results. Conclusions Inaccuracies in case ascertainment in administrative vs. clinical registry data can lead to important differences in assessment of hospital mortality rates for congenital heart surgery. PMID:25624057

Choice and competition between adult congenital heart disease centers: evidence of considerable geographical disparities and association with clinical or academic results.

PubMed

Diller, Gerhard-Paul; Kempny, Aleksander; Piorkowski, Adam; Grübler, Martin; Swan, Lorna; Baumgartner, Helmut; Dimopoulos, Konstantinos; Gatzoulis, Michael A

2014-03-01

Although concentrating adult congenital heart disease services at high-volume centers has been widely advocated, the potential beneficial effects of competition and patient choice have received relatively little attention. We aimed to assess the degree of patient choice and competition between adult congenital heart disease units and to investigate whether competition indices correlate with clinical quality or research output. Competition between the 10 major adult congenital heart disease units in England was evaluated based on the Herfindahl-Hirschman Index, representing the sum of squared market shares of individual units. In addition, to account for geography and feasible access, we calculated spatial indices of competition based on travel time by road. These indices were correlated with 30-day mortality postpulmonary valve replacement in adult patients (as obtained from the National Central Cardiac Audit Database) and the aggregate research impact factors of individual centers. On a national level, a high level of competition without obvious dominant players was found (Herfindahl-Hirschman Index between 0.107 and 0.013). When accounting for geography, however, important disparities in patient choice and competition faced by individual centers emerged. The degree of local competition was correlated significantly with clinical outcomes and research output. In contrast, no association between center volume and outcome could be established. Beyond the usual focus on concentrating services at high-volume centers, the potentially beneficial effects of competition should not be ignored. Therefore, policymakers should consider fostering a competitive environment for adult congenital heart disease centers or at least avoiding creating government-granted monopolies in the field.

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags

PubMed Central

Nelson, Todd G.; Zimmerman, Trent K.; Fernelius, Janette D.; Magleby, Spencer P.; Howell, Larry L.

2016-01-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the ‘flasher’ and the ‘inverted-cone fold’, for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver’s side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes. PMID:27703707

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags

NASA Astrophysics Data System (ADS)

Bruton, Jared T.; Nelson, Todd G.; Zimmerman, Trent K.; Fernelius, Janette D.; Magleby, Spencer P.; Howell, Larry L.

2016-09-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the `flasher' and the `inverted-cone fold', for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver's side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes.

Packing and deploying Soft Origami to and from cylindrical volumes with application to automotive airbags.

PubMed

Bruton, Jared T; Nelson, Todd G; Zimmerman, Trent K; Fernelius, Janette D; Magleby, Spencer P; Howell, Larry L

2016-09-01

Packing soft-sheet materials of approximately zero bending stiffness using Soft Origami (origami patterns applied to soft-sheet materials) into cylindrical volumes and their deployment via mechanisms or internal pressure (inflation) is of interest in fields including automobile airbags, deployable heart stents, inflatable space habitats, and dirigible and parachute packing. This paper explores twofold patterns, the 'flasher' and the 'inverted-cone fold', for packing soft-sheet materials into cylindrical volumes. Two initial packing methods and mechanisms are examined for each of the flasher and inverted-cone fold patterns. An application to driver's side automobile airbags is performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. Following deployment tests, two additional packing methods for the inverted-cone fold pattern are explored and applied to automobile airbags. It is shown that modifying the packing method (using different methods to impose the same base pattern on the soft-sheet material) can lead to different deployment performance. In total, two origami patterns and six packing methods are examined, and the benefits of using Soft Origami patterns and packing methods are discussed. Soft Origami is presented as a viable method for efficiently packing soft-sheet materials into cylindrical volumes.

Human Rehabilitation Techniques. Disability Analyses: Chronic Disease Disabilities. Volume II, Part C.

ERIC Educational Resources Information Center

Sigelman, C.; And Others

Volume II, Section C of a six-volume final report (which covers the findings of a research project on policy and technology related to rehabilitation of disabled individuals) presents a review of literature on six types of chronic disease disabilities--rheumatoid arthritis, coronary heart disease, emphysema, carcinoma of the colon/rectum, kidney…

[Experimental evaluation of the role of the coronary sinus pressure in the regulation of coronary return volume via the coronary sinus. Surgical considerations in atrio-pulmonary diversion procedures].

PubMed

Fantidis, P; Fernández Ruiz, M A; Madero Jarabo, R; Moreno Granados, F; Cordovilla Zurdo, G; Sanz Galeote, E

1990-11-01

In order to find out the validity of the vascular waterfall mechanism in coronary venous circulation, the role of coronary sinus pressure in the regulation of coronary return volume via the coronary sinus is studied in healthy animals. An experimental model of pressure regulation in the coronary sinus was prepared, and aortic pressure, EKG and the cardiac output (measured by thermodilution) were recorded. The return volume via the coronary sinus was measured at coronary sinus pressure of 10 or less, 15, 20, and 25 mmHg or more, for a total of 36 determinations. Increased coronary sinus pressure did not produce significant changes in aortic pressure, heart rate, cardiac index or coronary return volume via coronary sinus. When coronary sinus pressure was 25 mmHg or more, there was a significant decline in the average of coronary return volume via coronary sinus. Nevertheless, stepwise variant regression showed that the coronary sinus pressure per se does not condition the volume of coronary return via the coronary sinus. Our results suggest that in the healthy animals, the vascular waterfall mechanism in coronary venous circulation is not valid. Our results suggest that in the correction of congenital cardiac malformations using atriopulmonary anastomosis procedures, employing techniques that ensure coronary sinus drainage into the left atrium, in order to avoid the hemodynamic repercussions attributable to the vascular waterfall mechanism, is not justified.

Hammersmith cardiology workshop series. Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maseri, A.

1985-01-01

This book contains over 30 selections. Some of the titles are: Digital Subtraction Angiography: The Optimal Radiologic Technique for Cardiac Diagnosis; NMR Imaging of the Heart; Radioisotopes in the Evaluation of Right and Left Ventricular Function; Role of Membrane Abnormalities in the Pathogenesis of Heart Disease; and Influence of Arrhythmias on Cardiac Function.

Successful heart transplant after 1374 days living with a total artificial heart.

PubMed

Gerosa, Gino; Gallo, Michele; Bottio, Tomaso; Tarzia, Vincenzo

2016-04-01

The CardioWest Total Artificial Heart (CW-TAH) has been approved as a temporary device for bridge to cardiac transplantation and is under investigation for destination therapy by US Food and Drug Administration (FDA). We herein report the longest worldwide survival out of hospital (1374 days) of a patient supported with Cardio West Total Artificial Heart (CW-TAH). This experience is intended as a proof of concept of using CW-TAH as the destination therapy in patients with biventricular failure. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Analytical-Based Partial Volume Recovery in Mouse Heart Imaging

NASA Astrophysics Data System (ADS)

Dumouchel, Tyler; deKemp, Robert A.

2011-02-01

Positron emission tomography (PET) is a powerful imaging modality that has the ability to yield quantitative images of tracer activity. Physical phenomena such as photon scatter, photon attenuation, random coincidences and spatial resolution limit quantification potential and must be corrected to preserve the accuracy of reconstructed images. This study focuses on correcting the partial volume effects that arise in mouse heart imaging when resolution is insufficient to resolve the true tracer distribution in the myocardium. The correction algorithm is based on fitting 1D profiles through the myocardium in gated PET images to derive myocardial contours along with blood, background and myocardial activity. This information is interpolated onto a 2D grid and convolved with the tomograph's point spread function to derive regional recovery coefficients enabling partial volume correction. The point spread function was measured by placing a line source inside a small animal PET scanner. PET simulations were created based on noise properties measured from a reconstructed PET image and on the digital MOBY phantom. The algorithm can estimate the myocardial activity to within 5% of the truth when different wall thicknesses, backgrounds and noise properties are encountered that are typical of healthy FDG mouse scans. The method also significantly improves partial volume recovery in simulated infarcted tissue. The algorithm offers a practical solution to the partial volume problem without the need for co-registered anatomic images and offers a basis for improved quantitative 3D heart imaging.

Assessment of the physiologic contribution of right atrial function to total right heart function in patients with and without pulmonary arterial hypertension.

PubMed

Sivak, Joseph A; Raina, Amresh; Forfia, Paul R

2016-09-01

Total right heart function requires normal function of both the right ventricle and the right atrium. However, the degree to which right atrial (RA) function and right ventricular (RV) function each contribute to total right heart function has not been quantified. In this study, we aimed to quantify the contribution of RA function to total right heart function in a group of pulmonary arterial hypertension (PAH) patients compared to a cohort of normal controls without cardiovascular disease. The normal cohort comprised 35 subjects with normal clinical echocardiograms, while the PAH cohort included 37 patients, of whom 31 had echocardiograms before and after initiation of PAH-specific therapy. Total right heart function was measured via tricuspid annular plane excursion (TAPSE). TAPSE was broken down into two components, the excursion occurring during RA contraction (TAPSERA) and that occurring before RA contraction (TAPSERV). RA fractional area change (RA-FAC) was also compared between the two groups. In the PAH cohort, more than half of the total TAPSE occurred during atrial systole, compared to less than one-third in the normal cohort (51.0% vs. 32.1%; P < 0.0001). There was a significant correlation between RA-FAC and TAPSE in the PAH cohort but not in the normal cohort. TAPSE improved significantly in the posttreatment cohort (1.7 vs. 2.1 cm), but TAPSERA continued to account for about half of the total TAPSE after treatment. RA function accounts for a significantly greater proportion of total right heart function in patients with PAH than in normal subjects.

Assessment of the physiologic contribution of right atrial function to total right heart function in patients with and without pulmonary arterial hypertension

PubMed Central

Sivak, Joseph A.; Raina, Amresh

2016-01-01

Abstract Total right heart function requires normal function of both the right ventricle and the right atrium. However, the degree to which right atrial (RA) function and right ventricular (RV) function each contribute to total right heart function has not been quantified. In this study, we aimed to quantify the contribution of RA function to total right heart function in a group of pulmonary arterial hypertension (PAH) patients compared to a cohort of normal controls without cardiovascular disease. The normal cohort comprised 35 subjects with normal clinical echocardiograms, while the PAH cohort included 37 patients, of whom 31 had echocardiograms before and after initiation of PAH-specific therapy. Total right heart function was measured via tricuspid annular plane excursion (TAPSE). TAPSE was broken down into two components, the excursion occurring during RA contraction (TAPSERA) and that occurring before RA contraction (TAPSERV). RA fractional area change (RA-FAC) was also compared between the two groups. In the PAH cohort, more than half of the total TAPSE occurred during atrial systole, compared to less than one-third in the normal cohort (51.0% vs. 32.1%; P < 0.0001). There was a significant correlation between RA-FAC and TAPSE in the PAH cohort but not in the normal cohort. TAPSE improved significantly in the posttreatment cohort (1.7 vs. 2.1 cm), but TAPSERA continued to account for about half of the total TAPSE after treatment. RA function accounts for a significantly greater proportion of total right heart function in patients with PAH than in normal subjects. PMID:27683609

Calcium scoring with dual-energy CT in men and women: an anthropomorphic phantom study

NASA Astrophysics Data System (ADS)

Li, Qin; Liu, Songtao; Myers, Kyle; Gavrielides, Marios A.; Zeng, Rongping; Sahiner, Berkman; Petrick, Nicholas

2016-03-01

This work aimed to quantify and compare the potential impact of gender differences on coronary artery calcium scoring with dual-energy CT. An anthropomorphic thorax phantom with four synthetic heart vessels (diameter 3-4.5 mm: female/male left main and left circumflex artery) were scanned with and without female breast plates. Ten repeat scans were acquired in both single- and dual-energy modes and reconstructed at six reconstruction settings: two slice thicknesses (3 mm, 0.6 mm) and three reconstruction algorithms (FBP, IR3, IR5). Agatston and calcium volume scores were estimated from the reconstructed data using a segmentation-based approach. Total calcium score (summation of four vessels), and male/female calcium scores (summation of male/female vessels scanned in phantom without/with breast plates) were calculated accordingly. Both Agatston and calcium volume scores were found comparable between single- and dual-energy scans (Pearson r= 0.99, p<0.05). The total calcium scores were larger for the thinner slice thickness. Among the scores obtained from the three reconstruction algorithms, FBP yielded the highest and IR5 yielded the lowest scores. The total calcium scores from the phantom without breast plates were significantly larger than those from the phantom with breast plates, and the difference increased with the stronger denoising in iterative algorithm and with thicker slices. Both gender-based anatomical differences and vessel size impacted the calcium scores. The calcium volume scores tended to be underestimated when the vessels were smaller. These findings are valuable for understanding inconsistencies between women and men in calcium scoring, and for standardizing imaging protocols for improved gender-specific calcium scoring.

Physiological rules for the heart, lungs and other pressure-based organs

PubMed Central

Camilleri, Liberato; Manché, Alexander; Gatt, Ruben; Gauci, Marilyn; Camilleri-Podesta, Marie-Therese; Grima, Joseph N.; Chetcuti, Stanley

2017-01-01

Background The adherence of the heart to physical laws, such as Laplace’s Law, may act as a measure of the organ’s relative efficiency. Allometric relationships were investigated to assess the heart’s efficiency concerning end-diastolic and end-systolic volumes, cardiac pressurization energy, cardiac output and mass. Methods Data to generate allometric relationships was obtained using a literature search, identifying heart and lung data across different mammalian and bird species. Statistical analysis was carried out using ordinary least squares (OLS) estimation. Results Near isometric relationships exist between body mass and seven parameters indicating no “efficiency of size” with scaling of the heart, and size-matching of the heart to the lungs and whole body. Even though there was equal efficiency in pressurization energy generation, cardiac output was maximally efficient in small mammals <10 kg and birds; the human heart reached only 71% efficiency. This loss in cardiac efficiency with increasing body mass can be explained by the aortic cross-section that scales following the three-quarter allometry law, compared to end-systolic and end-diastolic volumes that scale isometrically. The heart is therefore throttled by a relatively small aorta at large body size. Conclusions Mammalian and avian hearts operate at similar efficiencies, demonstrating a high degree of symmorphosis, however cardiac output efficiency decreases in larger animals due to a relatively negative aortic cross-section allometry. This work has a myriad of potential applications including explaining cardiac dysfunction in athletes, patient-prosthesis mismatch in aortic valve replacement and why heavy exercise is associated with a worse prognosis than mild or moderate exercise. PMID:29268387

Intercostal and forearm muscle deoxygenation during respiratory fatigue in patients with heart failure: potential role of a respiratory muscle metaboreflex.

PubMed

Moreno, A M; Castro, R R T; Silva, B M; Villacorta, H; Sant'Anna Junior, M; Nóbrega, A C L

2014-11-01

The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66 ± 12 years; left ventricle ejection fraction, 34 ± 3%) and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as they could sustain the predetermined inspiratory pressure. Intercostal and forearm muscle blood volume and oxygenation were continuously monitored by near-infrared spectroscopy with transducers placed on the seventh left intercostal space and the left forearm. Data were compared by two-way ANOVA and Bonferroni correction. Respiratory fatigue occurred at 5.1 ± 1.3 min in heart failure patients and at 9.3 ± 1.4 min in controls (P<0.05), but perceived effort, changes in heart rate, and in systolic blood pressure were similar between groups (P>0.05). Respiratory fatigue in heart failure reduced intercostal and forearm muscle blood volume (P<0.05) along with decreased tissue oxygenation both in intercostal (heart failure, -2.6 ± 1.6%; controls, +1.6 ± 0.5%; P<0.05) and in forearm muscles (heart failure, -4.5 ± 0.5%; controls, +0.5 ± 0.8%; P<0.05). These results suggest that respiratory fatigue in patients with heart failure causes an oxygen demand/delivery mismatch in respiratory muscles, probably leading to a reflex reduction in peripheral limb muscle perfusion, featuring a respiratory metaboreflex.

Heart dosimetric analysis of three types of cardiac toxicity in patients treated on dose-escalation trials for Stage III non-small-cell lung cancer.

PubMed

Wang, Kyle; Pearlstein, Kevin A; Patchett, Nicholas D; Deal, Allison M; Mavroidis, Panayiotis; Jensen, Brian C; Lipner, Matthew B; Zagar, Timothy M; Wang, Yue; Lee, Carrie B; Eblan, Michael J; Rosenman, Julian G; Socinski, Mark A; Stinchcombe, Thomas E; Marks, Lawrence B

2017-11-01

To assess associations between radiation dose/volume parameters for cardiac subvolumes and different types of cardiac events in patients treated on radiation dose-escalation trials. Patients with Stage III non-small-cell lung cancer received dose-escalated radiation (median 74 Gy) using 3D-conformal radiotherapy on six prospective trials from 1996 to 2009. Volumes analyzed included whole heart, left ventricle (LV), right atrium (RA), and left atrium (LA). Cardiac events were divided into three categories: pericardial (symptomatic effusion and pericarditis), ischemia (myocardial infarction and unstable angina), and arrhythmia. Univariable competing risks analysis was used. 112 patients were analyzed, with median follow-up 8.8 years for surviving patients. Nine patients had pericardial, seven patients had ischemic, and 12 patients had arrhythmic events. Pericardial events were correlated with whole heart, RA, and LA dose (eg, heart-V30 [p=0.024], RA-V30 [p=0.013], and LA-V30 [p=0.001]), but not LV dose. Ischemic events were correlated with LV and whole heart dose (eg, LV-V30 [p=0.012], heart-V30 [p=0.048]). Arrhythmic events showed borderline significant associations with RA, LA, and whole heart dose (eg, RA-V30 [p=0.082], LA-V30 [p=0.076], heart-V30 [p=0.051]). Cardiac events were associated with decreased survival on univariable analysis (p=0.008, HR 2.09), but only disease progression predicted for decreased survival on multivariable analysis. Cardiac events were heterogeneous and associated with distinct heart subvolume doses. These data support the hypothesis of distinct etiologies for different types of radiation-associated cardiotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Theory of heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, L.; Hunter, P.; McCulloch, A.

1991-01-01

In recent years there has been a growth in interest in studying the heart from the perspective of the physical sciences: mechanics, fluid flow, electromechanics. This volume is the result of a workshop held in July 1989 at the Institute for Nonlinear Sciences at the University of California at San Diego that brought together scientists and clinicians with graduate students and postdoctoral fellows who share an interest in the heart. The chapters were prepared by the invited speakers as didactic reviews of their subjects but also include up-to-date results in their fields. Topics covered include the structure, mechanical properties, andmore » function of the heart and the myocardium, electrical activity of the heart and myocardium, and mathematical models of heart function. Individual chapters are abstracted separately.« less

Heart rate sensitive optical coherence angiography

NASA Astrophysics Data System (ADS)

Alvarez, Karl; Lopez-Tremoleda, Jordi; Donnan, Rob; Michael-Titus, Adina T.; Tomlins, Peter H.

2018-02-01

Optical coherence angiography (OCA) enables visualisation of three-dimensional micro-vasculature from optical coherence tomography data volumes. Typically, various statistical methods are used to discriminate static tissue from blood flow within vessels. In this paper, we introduce a new method that relies upon the beating heart frequency to isolate blood vessels from the surrounding tissue. Vascular blood flow is assumed to be more strongly modulated by the heart-beat compared to surrounding tissue and therefore short-time Fourier transform of sequential measurements can discriminate the two. Furthermore, it is demonstrated that adjacent B-Scans within an OCT data volume can provide the required sampling frequency. As such, the technique can be considered to be a spatially mapped variation of photoplethysmography (PPG), whereby each image voxel operates as a PPG detector. This principle is demonstrated using both a model system and in vivo for monitoring the vascular changes effected by traumatic brain injury in mice. In vivo measurements were acquired at an A-Scan rate of 10kHz to form a 500x500x512 (lateral x lateral x axial) pixel volume, enabling sequential sampling of the mouse heart rate in an expected range of 300-600 bpm. One of the advantages of this new OCA processing method is that it can be used in conjunction with existing algorithms as an additional filter for signal to noise enhancement.

Prognostic value of real-time three-dimensional echocardiography compared to two-dimensional echocardiography in patients with systolic heart failure.

PubMed

Mancuso, Frederico J N; Moises, Valdir A; Almeida, Dirceu R; Poyares, Dalva; Storti, Luciana J; Brito, Flavio S; Tufik, Sergio; de Paola, Angelo A V; Carvalho, Antonio C C; Campos, Orlando

2018-04-01

Heart failure (HF) is associated with morbidity and mortality. Real-time three-dimensional echocardiography (RT3DE) may offer additional prognostic data in patients with HF. The study aimed to evaluate the prognostic value of real-time three-dimensional echocardiography (RT3DE). This is a prospective study that included 89 patients with HF and left ventricular ejection fraction (LVEF) < 0.50 who were followed for 48 months. Left atrium and ventricular volumes and functions were evaluated by RT3DE. TDI and two-dimensional echocardiography parameters were also obtained. The endpoint was a composite of death, heart transplantation and hospitalization for acute decompensated HF. The mean age was 55 ± 11 years, and the LVEF was 0.32 ± 0.10. The composite endpoint occurred in 49 patients (18 deaths, 30 hospitalizations, one heart transplant). Patients with outcomes had greater left atrial volume (40 ± 16 vs. 32 ± 12 mL/m 2 ; p < 0.01) and right ventricle diameter (41 ± 9 vs. 37 ± 8 mm, p = 0.01), worse total emptying fraction of the left atrium (36 ± 13% vs. 41 ± 11%; p = 0.03), LVEF (0.30 ± 0.09 vs. 0.34 ± 0.11; p = 0.02), right ventricle fractional area change (34.8 ± 12.1% vs. 39.2 ± 11.3%; p = 0.04), and greater E/e' ratio (19 ± 9 vs. 16 ± 8; p = 0.04) and systolic pulmonary artery pressure (SPAP) (50 ± 15 vs. 36 ± 11 mmHg; p < 0.01). In multivariate analysis, LVEF (OR 4.6; CI 95% 1.2-17.6; p < 0.01) and SPAP (OR 12.5; CI 95% 1.8-86.9; p < 0.01) were independent predictors of patient outcomes. LVEF and the SPAP were independent predictors of outcomes in patients with HF.

Cardiorespiratory interactions in humans and animals: Rhythms for life.

PubMed

Elstad, Maja; O'Callaghan, Erin L; Smith, Alexander J; Ben-Tal, A; Ramchandra, Rohit

2018-03-09

The cardiorespiratory system exhibits oscillations from a range of sources. One of the most studied oscillations is heart rate variability, which is thought to be beneficial and can serve as an index of a healthy cardiovascular system. Heart rate variability is dampened in many diseases including depression, autoimmune diseases, hypertension and heart failure. Thus, understanding the interactions that lead to heart rate variability, and its physiological role, could help with prevention, diagnosis and treatment of cardiovascular diseases. In this review we consider three types of cardiorespiratory interactions; Respiratory Sinus Arrhythmia - variability in heart rate at the frequency of breathing, Cardioventilatory Coupling - synchronization between the heart beat and the onset of inspiration, and Respiratory Stroke Volume Synchronization - constant phase difference between the right and the left stroke volumes over one respiratory cycle. While the exact physiological role of these oscillations continues to be debated, the redundancies in the mechanisms responsible for its generation and its strong evolutionary conservation point to the importance of cardiorespiratory interactions. The putative mechanisms driving cardiorespiratory oscillations as well as the physiological significance of these oscillations will be reviewed. We suggest that cardiorespiratory interactions have the capacity to both dampen the variability in systemic blood flow as well as improve the efficiency of work done by the heart while maintaining physiological levels of arterial CO 2 . Given that reduction in variability is a prognostic indicator of disease, we argue that restoration of this variability via pharmaceutical or device-based approaches may be beneficial in prolonging life.

Flow dynamics and energy efficiency of flow in the left ventricle during myocardial infarction.

PubMed

Vasudevan, Vivek; Low, Adriel Jia Jun; Annamalai, Sarayu Parimal; Sampath, Smita; Poh, Kian Keong; Totman, Teresa; Mazlan, Muhammad; Croft, Grace; Richards, A Mark; de Kleijn, Dominique P V; Chin, Chih-Liang; Yap, Choon Hwai

2017-10-01

Cardiovascular disease is a leading cause of death worldwide, where myocardial infarction (MI) is a major category. After infarction, the heart has difficulty providing sufficient energy for circulation, and thus, understanding the heart's energy efficiency is important. We induced MI in a porcine animal model via circumflex ligation and acquired multiple-slice cine magnetic resonance (MR) images in a longitudinal manner-before infarction, and 1 week (acute) and 4 weeks (chronic) after infarction. Computational fluid dynamic simulations were performed based on MR images to obtain detailed fluid dynamics and energy dynamics of the left ventricles. Results showed that energy efficiency flow through the heart decreased at the acute time point. Since the heart was observed to experience changes in heart rate, stroke volume and chamber size over the two post-infarction time points, simulations were performed to test the effect of each of the three parameters. Increasing heart rate and stroke volume were found to significantly decrease flow energy efficiency, but the effect of chamber size was inconsistent. Strong complex interplay was observed between the three parameters, necessitating the use of non-dimensional parameterization to characterize flow energy efficiency. The ratio of Reynolds to Strouhal number, which is a form of Womersley number, was found to be the most effective non-dimensional parameter to represent energy efficiency of flow in the heart. We believe that this non-dimensional number can be computed for clinical cases via ultrasound and hypothesize that it can serve as a biomarker for clinical evaluations.

Augmented baroreflex heart rate gain after moderate-intensity, dynamic exercise

NASA Technical Reports Server (NTRS)

Halliwill, J. R.; Taylor, J. A.; Hartwig, T. D.; Eckberg, D. L.

1996-01-01

The occurrence of a sustained vasodilation and hypotension after acute, dynamic exercise suggests that exercise may alter arterial baroreflex mechanisms. Therefore, we assessed systemic hemodynamics, baroreflex regulation of heart rate, and cardiac vagal tone after 60 min of cycling at 60% peak oxygen consumption in 12 healthy, untrained men and women (ages 21-28 yr). We derived sigmoidal carotid-cardiac baroreflex relations by measurement of R-R interval changes induced by ramped, stepwise, R-wave-triggered changes in external neck pressure from 40 to -65 mmHg. We estimated tonic cardiac vagal control with power spectral analysis of R-R interval variability in the respiratory frequency band (0.2-0.3 Hz) during frequency- and tidal volume-controlled breathing. Both mean arterial pressure and total peripheral resistance were reduced postexercise [pressure: from 86 +/- 2 (mean +/- SE) to 81 +/- 2 mmHg; resistance: from 23 +/- 2 to 16 +/- 1 units; both P < 0.05]. Cardiac output was increased postexercise (from 3.9 +/- 0.3 to 5.5 +/- 0.5 l/min, P < 0.05). Both slope and range of the carotid-cardiac baroreflex relation were increased postexercise (slope: from 4.7 +/- 0.7 to 6.1 +/- 0.9 ms/mmHg; range: from 186 +/- 23 to 238 +/- 30 ms, P < 0.05). Respiratory R-R interval variability (cardiac vagal tone) was not changed at any time after exercise, whereas heart rate and plasma norepinephrine levels were elevated. Thus moderate-intensity, dynamic exercise increases heart rate and cardiac output, reduces peripheral vascular resistance, and augments baroreflex responsiveness. Our data suggest that augmented baroreflex heart rate gain restrains rather than contributes to postexercise hypotension, which appears to be mediated predominately by vasodilation.

Short-Term Thyroid Hormone Excess Affects the Heart but Does not Affect Adrenal Activity in Rats

PubMed Central

Szkudlarek, Ariani Cavazzani; Aldenucci, Bruno; Miyagui, Nelson Itiro; Silva, Ilana Kassouf; Moraes, Rosana Nogueira; Ramos, Helton Estrela; Fogaça, Rosalva Tadeu Hochmuller

2014-01-01

Background Hyperthyroidism (Hy) exerts a broad range of influences on a variety of physiological parameters. Its disruptive effect on cardiovascular system is one of its most remarkable impacts. Moreover, Hy has been clinically associated with stress - induced hyperactivation of the hypothalamic-pituitary-adrenal axis. Objective Evaluate the impact of short-term Hy on cardiac performance and adrenal activity of rats. Methods Induction of Hy in Wistar rats through injections of T3 (150 µg/kg) for 10 days (hyperthyroid group - HG) or vehicle (control group). The cardiovascular performance was evaluated by: echocardiography (ECHO); heart weight/body weight (mg/gr) ratio; contractility of isolated papillary muscles (IPM) and direct measurement of blood pressures. Adrenal activity was evaluated by adrenal weight/body weight (mg/gr) ratio and 24-hour fecal corticosterone (FC) levels on the, 5th and 10th days of T3 treatment. Results In HG, the ECHO showed reduction of the End Systolic and End Diastolic Volumes, Ejection, Total Diastolic and Isovolumic Relaxation Times, Diastolic and Systolic Areas and E/A ratio. Heart Rate, Ejection Fraction and Cardiac Output increased. The heart weight/body weight ratio was higher. Similarly, in IPM, the maximum rate of force decay during relaxation was higher in all extracellular calcium concentrations. Systolic blood pressure (SBP) levels were higher. (p ≤ 0.05). On the other hand, there was no difference in the adrenal weight/body weight ratio or in the 24-hour FC levels. Conclusions Hy induces positive inotropic, chronotropic and lusitropic effects on the heart by direct effects of T3 and increases SBP. Those alterations are not correlated with changes in the adrenal activity. PMID:24676225

Clinical usefulness of the definitions for defining characteristics of activity intolerance, excess fluid volume and decreased cardiac output in decompensated heart failure: a descriptive exploratory study.

PubMed

de Souza, Vanessa; Zeitoun, Sandra Salloum; Lopes, Camila Takao; de Oliveira, Ana Paula Dias; Lopes, Juliana de Lima; de Barros, Alba Lucia Bottura Leite

2015-09-01

To assess the clinical usefulness of the operational definitions for the defining characteristics of the NANDA International nursing diagnoses, activity intolerance, decreased cardiac output and excess fluid volume, and the concomitant presence of those diagnoses in patients with decompensated heart failure. Content validity of the operational definitions for the defining characteristics of activity intolerance, excess fluid volume and decreased cardiac output have been previously validated by experts. Their clinical usefulness requires clinical validation. This was a descriptive exploratory study. Two expert nurses independently assessed 25 patients with decompensated heart failure for the presence or absence of 29 defining characteristics. Interrater reliability was analysed using the Kappa coefficient as a measure of clinical usefulness. The Fisher's exact test was used to test the association of the defining characteristics of activity intolerance and excess fluid volume in the presence of decreased cardiac output, and the correlation between the three diagnoses. Assessments regarding the presence of all defining characteristics reached 100% agreement, except with anxiety. Five defining characteristics of excess fluid volume were significantly associated with the presence of decreased cardiac output. Concomitant presence of the three diagnoses occurred in 80% of the patients. However, there was no significant correlation between the three diagnoses. The operational definitions for the diagnoses had strong interrater reliability, therefore they were considered clinically useful. Only five defining characteristics were representative of the association between excess fluid volume and decreased cardiac output. Therefore, excess fluid volume is related to decreased cardiac output, although these diagnoses are not necessarily associated with activity intolerance. The operational definitions may favour early recognition of the sequence of responses to decompensation, guiding the choice of common interventions to improve or resolve excess fluid volume and decreased cardiac output. © 2015 John Wiley & Sons Ltd.

Total Artificial Heart as Rescue Therapy for Primary Graft Failure in an Infant.

PubMed

Ziegler, Luke A; Sainathan, Sandeep; Morell, Victor O; Sharma, Mahesh S

2018-04-01

An infant unable to be weaned from cardiopulmonary bypass after orthotopic heart transplantation was cannulated for extracorporeal membrane oxygenation. During the next 3 days, allograft failure and intracardiac thrombosis necessitated cardiectomy. To provide acute mechanical circulatory support, artificial atrial chambers were constructed with Gore-Tex conduits and PediMag centrifugal pumps were connected to each by Berlin Heart EXCOR cannulae. The PediMag pumps were subsequently exchanged for 10-mL Berlin Heart EXCOR pumps. After 60 days of support by total artificial heart, the patient was bridged successfully to a second heart transplant. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Closing the loop: modelling of heart failure progression from health to end-stage using a meta-analysis of left ventricular pressure-volume loops.

PubMed

Warriner, David R; Brown, Alistair G; Varma, Susheel; Sheridan, Paul J; Lawford, Patricia; Hose, David R; Al-Mohammad, Abdallah; Shi, Yubing

2014-01-01

The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models. A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax). For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.

Quantifying the impact of immediate reconstruction in postmastectomy radiation: a large, dose-volume histogram-based analysis.

PubMed

Ohri, Nisha; Cordeiro, Peter G; Keam, Jennifer; Ballangrud, Ase; Shi, Weiji; Zhang, Zhigang; Nerbun, Claire T; Woch, Katherine M; Stein, Nicholas F; Zhou, Ying; McCormick, Beryl; Powell, Simon N; Ho, Alice Y

2012-10-01

To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data. Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment. Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P<.0001). These associations persisted on propensity-matched analysis (all P<.0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 >98%). IMN coverage was superior in patients with reconstruction (D95 >92.0 vs 75.7%, P<.001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P<.05) but minimally affected those without reconstruction (all P>.05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P=.022), and mean and maximum heart doses were higher than in patients without reconstruction (P=.006, P=.015, respectively). Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary determinant of target coverage and normal tissue doses. Published by Elsevier Inc.

Radiobiological Determination of Dose Escalation and Normal Tissue Toxicity in Definitive Chemoradiation Therapy for Esophageal Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Samantha, E-mail: Samantha.warren@oncology.ox.ac.uk; Partridge, Mike; Carrington, Rhys

2014-10-01

Purpose: This study investigated the trade-off in tumor coverage and organ-at-risk sparing when applying dose escalation for concurrent chemoradiation therapy (CRT) of mid-esophageal cancer, using radiobiological modeling to estimate local control and normal tissue toxicity. Methods and Materials: Twenty-one patients with mid-esophageal cancer were selected from the SCOPE1 database (International Standard Randomised Controlled Trials number 47718479), with a mean planning target volume (PTV) of 327 cm{sup 3}. A boost volume, PTV2 (GTV + 0.5 cm margin), was created. Radiobiological modeling of tumor control probability (TCP) estimated the dose required for a clinically significant (+20%) increase in local control as 62.5more » Gy/25 fractions. A RapidArc (RA) plan with a simultaneously integrated boost (SIB) to PTV2 (RA{sub 62.5}) was compared to a standard dose plan of 50 Gy/25 fractions (RA{sub 50}). Dose-volume metrics and estimates of normal tissue complication probability (NTCP) for heart and lungs were compared. Results: Clinically acceptable dose escalation was feasible for 16 of 21 patients, with significant gains (>18%) in tumor control from 38.2% (RA{sub 50}) to 56.3% (RA{sub 62.5}), and only a small increase in predicted toxicity: median heart NTCP 4.4% (RA{sub 50}) versus 5.6% (RA{sub 62.5}) P<.001 and median lung NTCP 6.5% (RA{sub 50}) versus 7.5% (RA{sub 62.5}) P<.001. Conclusions: Dose escalation to the GTV to improve local control is possible when overlap between PTV and organ-at-risk (<8% heart volume and <2.5% lung volume overlap for this study) generates only negligible increase in lung or heart toxicity. These predictions from radiobiological modeling should be tested in future clinical trials.« less

Simulation of Dose to Surrounding Normal Structures in Tangential Breast Radiotherapy Due to Setup Error

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhakar, Ramachandran; Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi; Department of Radiology, All India Institute of Medical Sciences, New Delhi

Setup error plays a significant role in the final treatment outcome in radiotherapy. The effect of setup error on the planning target volume (PTV) and surrounding critical structures has been studied and the maximum allowed tolerance in setup error with minimal complications to the surrounding critical structure and acceptable tumor control probability is determined. Twelve patients were selected for this study after breast conservation surgery, wherein 8 patients were right-sided and 4 were left-sided breast. Tangential fields were placed on the 3-dimensional-computed tomography (3D-CT) dataset by isocentric technique and the dose to the PTV, ipsilateral lung (IL), contralateral lung (CLL),more » contralateral breast (CLB), heart, and liver were then computed from dose-volume histograms (DVHs). The planning isocenter was shifted for 3 and 10 mm in all 3 directions (X, Y, Z) to simulate the setup error encountered during treatment. Dosimetric studies were performed for each patient for PTV according to ICRU 50 guidelines: mean doses to PTV, IL, CLL, heart, CLB, liver, and percentage of lung volume that received a dose of 20 Gy or more (V20); percentage of heart volume that received a dose of 30 Gy or more (V30); and volume of liver that received a dose of 50 Gy or more (V50) were calculated for all of the above-mentioned isocenter shifts and compared to the results with zero isocenter shift. Simulation of different isocenter shifts in all 3 directions showed that the isocentric shifts along the posterior direction had a very significant effect on the dose to the heart, IL, CLL, and CLB, which was followed by the lateral direction. The setup error in isocenter should be strictly kept below 3 mm. The study shows that isocenter verification in the case of tangential fields should be performed to reduce future complications to adjacent normal tissues.« less

Echocardiography in the flight program

NASA Technical Reports Server (NTRS)

Charles, John B.; Bungo, Michael W.; Mulvagh, Sharon L.

1991-01-01

Observations on American and Soviet astronauts have documented the association of changes in cardiovascular function during orthostasis with space flight. A basic understanding of the cardiovascular changes occurring in astronauts requires the determination of cardiac output and total peripheral vascular resistance as a minimum. In 1982, we selected ultrasound echocardiography as our means of acquiring this information. Ultrasound offers a quick, non-invasive and accurate means of determining stroke volume which, when combined with the blood pressure and heart rate measurements of the stand test, allows calculation of changes in peripheral vascular resistance, the body's major response to orthostatic stress. The history of echocardiography in the Space Shuttle Program is discussed and the results are briefly presented.

Anatomy of the bovine ascending aorta and brachiocephalic artery found unfavorable for total artificial heart implant.

PubMed

Karimov, Jamshid H; Sunagawa, Gengo; Such, Kimberly A; Sale, Shiva; Golding, Leonard A R; Moazami, Nader; Fukamachi, Kiyotaka

2015-12-01

The biocompatibility assessment of the Cleveland Clinic continuous-flow total artificial heart is an important part of the device developmental program. Surgical and postoperative management are key factors in achieving optimal outcomes. However, the presence of vascular anatomical abnormalities in experimental animal models is often unpredictable and may worsen the expected outcomes. We report a technical impediment encountered during total artificial heart implantation complicated by unfavorable bovine anatomy of the ascending aorta and brachiocephalic arterial trunk.

Post-explant visualization of thrombi in outflow grafts and their junction to a continuous-flow total artificial heart using a high-definition miniaturized camera.

PubMed

Karimov, Jamshid H; Horvath, David; Sunagawa, Gengo; Byram, Nicole; Moazami, Nader; Golding, Leonard A R; Fukamachi, Kiyotaka

2015-12-01

Post-explant evaluation of the continuous-flow total artificial heart in preclinical studies can be extremely challenging because of the device's unique architecture. Determining the exact location of tissue regeneration, neointima formation, and thrombus is particularly important. In this report, we describe our first successful experience with visualizing the Cleveland Clinic continuous-flow total artificial heart using a custom-made high-definition miniature camera.

Embryonic cardiac morphometry in Carnegie stages 15-23, from the Complutense University of Madrid Institute of Embryology Human Embryo Collection.

PubMed

Arráez-Aybar, L A; Turrero-Nogués, A; Marantos-Gamarra, D G

2008-01-01

We performed a morphometric study of cardiac development on human embryos to complement the scarce data on human embryonic cardiac morphometry and to attempt to establish, from these, algorithms describing cardiac growth during the second month of gestation. Thirty human embryos from Carnegie stages 15-23 were included in the study. Shrinkage and compression effects from fixation and inclusion in paraffin were considered in our calculations. Growth of the cardiac (whole heart) volume and volume of ventricular myocardium through the Carnegie stages were analysed by ANOVA. Linear correlation was used to describe the relationship between the ventricular myocardium and cardiac volumes. Comparisons of models were carried out through the R2 statistic. The relationship volume of ventricular myocardium versus cardiac volume is expressed by the equation: cardiac volume = 0.6266 + 2.4778 volume of ventricular myocardium. The relationship cardiac volume versus crown-rump length is expressed by the equation: cardiac volume = 1.3 e(0.126 CR length), where e is the base of natural logarithms. At a clinical level, these results can contribute towards the establishment of a normogram for cardiac development, useful for the design of strategies for early diagnosis of congenital heart disease. They can also help in the study of embryogenesis, for example in the discussion of ventricular trabeculation. Copyright 2007 S. Karger AG, Basel.

Israel: coronary and structural heart interventions from 2010 to 2015.

PubMed

Finkelstein, Ariel; Minha, Saar; Kornowski, Ran; Danenberg, Haim; Banai, Shmuel; Lotan, Haim; Segev, Amit; Barbash, Israel M

2017-05-15

The Israel Heart Society is a member of the European Society of Cardiology, and the Israeli Working Group of Interventional Cardiology is an active participant in EAPCI. The aim of this manuscript is to provide a snapshot of cardiac interventions performed in the State of Israel during the period 2010-2015. Data for this manuscript were collected via collaboration with the National Diseases Registries Unit of the Israel Center for Disease Control. During the survey period, the Israeli population increased by 7% but only one additional hospital with an active cardiac catheterisation laboratory was opened. The vast majority of the percutaneous procedures are performed in public hospital settings. Total coronary angiography procedures remained stable throughout the survey period, and the percentage of PCI out of total coronary angiography procedures remained approximately 50% throughout the survey period. More than 90% of the PCI procedures were performed using stent deployment, and the use of drug-eluting stents increased significantly during the survey period from 46% in 2010 to 92% in 2015. The number of TAVI procedures increased dramatically, by more than sixfold, from 130 procedures in 2010 to 851 procedures in 2015 (with 130 implants/million population at Q4 of 2015). The vast majority of interventional cardiology procedures are funded by the governmental healthcare providers, and all the citizens of the country have access to the most advanced cardiac interventions. If corrected for the increase in the population, the volumes of coronary interventions are decreasing throughout the country. However, structural heart disease interventions, and specifically valvular interventions, are growing rapidly and this trend is expected to continue in the near future.

A first step beyond traditional boundaries: destination therapy with the SynCardia total artificial heart.

PubMed

Spiliopoulos, Sotirios; Koerfer, Reiner; Tenderich, Gero

2014-06-01

The SynCardia total artificial heart is currently used as a bridge to transplantation therapy in cases of irreversible, acute or chronic, biventricular heart failure. We describe the implementation of this technology in the context of destination therapy in a patient with an end-stage heart failure on grounds of primary amyloidosis. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

What Is Heart Surgery?

MedlinePlus

... heart surgery that is becoming more common is robotic-assisted surgery. For this surgery, a surgeon uses a computer ... surgeon always is in total control of the robotic arms; they don't move on their own. Who Needs Heart Surgery? Heart surgery is used to treat many heart ...

Electrolyte-carbohydrate beverage prevents water loss in the early stage of high altitude training.

PubMed

Yanagisawa, Kae; Ito, Osamu; Nagai, Satsuki; Onishi, Shohei

2012-01-01

To prevent water loss in the early stage of high altitude training, we focused on the effect of electrolyte-carbohydrate beverage (EC). Subjects were 16 male university students who belonged to a ski club. They had ski training at an altitude of 1,800 m. The water (WT) group drank only water, and the EC group drank only an electrolyte-carbohydrate beverage. They arrived at the training site in the late afternoon. The study started at 7 pm on the day of arrival and continued until noon of the 4(th) day. In the first 12 hours, 1 L of beverages were given. On the second and third days, 2.5 L of beverages were given. All subjects ate the same meals. Each morning while in fasting condition, subjects were weighed and blood was withdrawn for various parameters (hemoglobin, hematocrit, sodium, potassium and aldosterone). Urine was collected at 12 hour intervals for a total 60 hours (5 times). The urine volume, gravity, sodium and potassium concentrations were measured. Peripheral oxygen saturation and heart rate were measured during sleep with a pulse oximeter. Liquid intakes in both groups were similar, hence the electrolytes intake was higher in the EC group than in the WT group. The total urine volume was lower in the EC group than in the WT group, respectively (p<0.05). Plasma volume decreased in the WT group and increased in the EC group but a significant difference was not observed in the final value. Aldosterone concentration tended to be less in the EC group than in the WT group. Electrolyte-carbohydrate beverage in the early stage of high altitude training may be effective in decreasing urinary output and preventing loss of blood plasma volume.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paliwal, B; Asprey, W; Yan, Y

Purpose: In order to take advantage of the high resolution soft tissue imaging available in MR images, we investigated 3D images obtained with the low field 0.35 T MR in ViewRay to serve as an alternative to CT scans for radiotherapy treatment planning. In these images, normal and target structure delineation can be visualized. Assessment is based upon comparison with the CT images and the ability to produce comparable contours. Methods: Routine radiation oncology CT scans were acquired on five patients. Contours of brain, brainstem, esophagus, heart, lungs, spinal cord, and the external body were drawn. The same five patientsmore » were then scanned on the ViewRay TrueFISP-based imaging pulse sequence. The same organs were selected on the MR images and compared to those from the CT scan. Physical volume and the Dice Similarity Coefficient (DSC) were used to assess the contours from the two systems. Image quality stability was quantitatively ensured throughout the study following the recommendations of the ACR MR accreditation procedure. Results: The highest DSC of 0.985, 0.863, and 0.843 were observed for brain, lungs, and heart respectively. On the other hand, the brainstem, spinal cord, and esophagus had the lowest DSC. Volume agreement was most satisfied for the heart (within 5%) and the brain (within 2%). Contour volume for the brainstem and lung (a widely dynamic organ) varied the most (27% and 19%). Conclusion: The DSC and volume measurements suggest that the results obtained from ViewRay images are quantitatively consistent and comparable to those obtained from CT scans for the brain, heart, and lungs. MR images from ViewRay are well-suited for treatment planning and for adaptive MRI-guided radiotherapy. The physical data from 0.35 T MR imaging is consistent with our geometrical understanding of normal structures.« less

Variations of intrathoracic amount of blood as a reason of ECG voltage changes.

PubMed

Saltykova, Marina; Capderou, Andre; Atkov, Oleg; Gusakov, Victor; Konovalov, Gennagiy; Voronin, Leonid; Kaspranskiy, Rustem; Morgun, Valeriy; Bailliart, Olivier; Cermack, Milan; Vaïda, Pierre

2003-10-01

It is known that electroconduction of intrathoracic organs and tissues significantly influences the ECG voltage. It changes during therapy or exercise test due to redistribution and/or volume variations of blood and body fluids and their electroconductivity variations. This fact must be taken into consideration during interpretation of corresponding ECG. But there are no quantitative estimations of this influence on human ECG. The goals of this study were to estimate the influence of variations of thoracic electroconduction, and heart volume on QRS voltage in humans, due to gravity change. ECGs of 26 healthy volunteers were analyzed in upright and supine position. Experimental conditions-acute change of gravity--are created in a special aircraft flying on Kepler's parabola trajectory. Each parabola includes phases of normo-, hypergravity (blood shifts in caudal direction), and microgravity (blood redistributes in cranial direction). Amplitude of QRS in Frank leads in all phases has been analyzed. 2-D echo studies for six subjects were used for estimation of heart volume change. In an upright position during hypergravity the amplitude of R wave in Z increases in 95% of cases (mean 0.19 mV). During microgravity amplitude of R wave in Z decreases in 95% (mean 0.24 mV). In supine position changes of QRS voltage are not significantly. Blood redistribution during gravity change leads to changes of QRS voltage, which is more expressed and steady on R in Z lead: an average near 0.2 mV. It is due to the balance between two factors: (a). changes of degree of short circuiting by variations in the amount of blood in thorax (b). changes of distance between heart and electrodes as a result of change in the position, form, and volume of the heart.

Payer leverage and hospital compliance with a benchmark: a population-based observational study

PubMed Central

Hollingsworth, John M; Krein, Sarah L; Miller, David C; DeMonner, Sonya; Hollenbeck, Brent K

2007-01-01

Background Since 1976, Medicare has linked reimbursement for hospitals performing organ transplants to the attainment of certain benchmarks, including transplant volume. While Medicare is a stakeholder in all transplant services, its role in renal transplantation is likely greater, given its coverage of end-stage renal disease. Thus, Medicare's transplant experience allows us to examine the role of payer leverage in motivating hospital benchmark compliance. Methods Nationally representative discharge data for kidney (n = 29,272), liver (n = 7,988), heart (n = 3,530), and lung (n = 1,880) transplants from the Nationwide Inpatient Sample (1993 – 2003) were employed. Logistic regression techniques with robust variance estimators were used to examine the relationship between hospital volume compliance and Medicare market share; generalized estimating equations were used to explore the association between patient-level operative mortality and hospital volume compliance. Results Medicare's transplant market share varied by organ [57%, 28%, 27%, and 18% for kidney, lung, heart, and liver transplants, respectively (P < 0.001)]. Volume-based benchmark compliance varied by transplant type [85%, 75%, 44%, and 39% for kidney, liver, heart, and lung transplants, respectively (P < 0.001)], despite a lower odds of operative mortality at compliant hospitals. Adjusting for organ supply, high market leverage was independently associated with compliance at hospitals transplanting kidneys (OR, 143.00; 95% CI, 18.53 – 1103.49), hearts (OR, 2.84; 95% CI, 1.51 – 5.34), and lungs (OR, 3.24; 95% CI, 1.57 – 6.67). Conclusion These data highlight the influence of payer leverage–an important contextual factor in value-based purchasing initiatives. For uncommon diagnoses, these data suggest that at least 30% of a provider's patients might need to be "at risk" for an incentive to motivate compliance. PMID:17640364

Specialized physiological studies in support of manned space flight

NASA Technical Reports Server (NTRS)

Luft, U. C.

1976-01-01

Subjects were tested for tolerance to lower body negative pressure (LBNP) before and after acute dehydration by working intermittenly for two hours without fluid replacement. On the second day there-after the LBNP tests were repeated before and after acute dehydration. The LBNP test consisted of 5 min long consective stages at -20, -30, -40, -50 and -60 Torr. Tests were terminated when syncope was imminent or the full sequence was completed. Tolerance was expressed in terms of cumulative stress in Torr x min. Measurements of body mass, density, fat fraction and total body water (TBW) were made before and after acclimation. Blood volume and its constituents were determined before and after each of the four LBNP tests. During LBNP, heart rate, blood pressure, and changes in calf and forearm volume were recorded every minute. Results showed: acute dehydration caused a significant loss in average LBNP tolerance on all subjects. Acclimation to heat did not significantly affect LBNP tolerance in hydrated subjects but significantly improved it on dehydrated subjects.

Determinants and predictors of the cost of COPD in primary care: A Spanish perspective

PubMed Central

de Miguel Diez, Javier; Garrido, Pilar Carrasco; Carballo, Marta García; de Miguel, Angel Gil; Gutierrez, Javier Rejas; Cano, José M Bellón; Barrera, Valentín Hernández; García, Rodrigo Jimenez

2008-01-01

Objectives 1) To estimate the annual cost of patients with stable chronic obstructive pulmonary disease (COPD) followed in primary care in Spain; 2) To analyze the possible cost predictor variables. Patients and methods A multicenter, epidemiological, observational, descriptive study. Sociodemographic data, severity of disease, associated comorbidity, treatment followed by patients, quality of life (SF-12 questionnaire), health care resource utilization in the previous 12 months and duration of working disability due to COPD were collected. Results A total of 10,711 patients (75.6% men; 24.4% women) with a mean age of 67.1 ± 9.66 years were evaluated. The mean forced expiratory volume in one second (FEV1) value was 57.4 ± 13.4%. The total cost per patient per year was €1,922.60 ± 2,306.44. The largest component of this cost was hospitalization (€788.72 ± 1,766.65), followed by cost of drugs (€492.87 ± 412.15) and visits to emergency rooms (€134.32 ± 195.44). Linear regression analysis found associated heart disease, FEV1, physical component of quality of life, number of medical visits (primary care physician, pneumologist and emergency room), hospital admissions (frequency and duration of stay) and duration of working disability to be significant predictors of the total annual cost. Conclusions The total annual cost of a COPD patient followed in primary care in Spain was considered high in this study. The presence of associated heart disease, severity of airflow obstruction, physical component of quality of life, health care resource utilization and duration of work disability were found to be predictor of cost. PMID:19281084

Facing Up to the Learning Organization Challenge: Selected European Writings. Volume II. CEDEFOP Reference Series.

ERIC Educational Resources Information Center

Nyhan, Barry, Ed.; Kelleher, Michael, Ed.; Cressey, Peter, Ed.; Poell, Rob, Ed.

This volume, the second of a two-volume publication, comprises 15 papers that present the work of individual European projects dealing with learning within organizations. These five chapters in Part 1, The Meaning of the Learning Organization, examine the conceptual frameworks and dilemmas at the heart of the notion of the learning organization:…

Ontological Modeling of Transformation in Heart Defect Diagrams

PubMed Central

Viswanath, Venkatesh; Tong, Tuanjie; Dinakarpandian, Deendayal; Lee, Yugyung

2006-01-01

The accurate portrayal of a large volume data of variable heart defects is crucial to providing good patient care in pediatric cardiology. Our research aims to span the universe of congenital heart defects by generating illustrative diagrams that enhance data interpretation. To accommodate the range and severity of defects to be represented, we base our diagrams on transformation models applied to a normal heart rather than a static set of defects. These models are based on a domain-specific ontology, clustering, association rule mining and the use of parametric equations specified in a mathematical programming language. PMID:17238451

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tobler, Matt; Watson, Gordon; Leavitt, Dennis

Radiotherapy plays a key role in the definitive or adjuvant management of patients with mesothelioma of the pleural surface. Many patients are referred for radiation with intact lung following biopsy or subtotal pleurectomy. Delivery of efficacious doses of radiation to the pleural lining while avoiding lung parenchyma toxicity has been a difficult technical challenge. Using opposed photon fields produce doses in lung that result in moderate-to-severe pulmonary toxicity in 100% of patients treated. Combined photon-electron beam treatment, at total doses of 4250 cGy to the pleural surface, results in two-thirds of the lung volume receiving over 2100 cGy. We havemore » developed a technique using intensity-modulated photon arc therapy (IMRT) that significantly improves the dose distribution to the pleural surface with concomitant decrease in dose to lung parenchyma compared to traditional techniques. IMRT treatment of the pleural lining consists of segments of photon arcs that can be intensity modulated with varying beam weights and multileaf positions to produce a more uniform distribution to the pleural surface, while at the same time reducing the overall dose to the lung itself. Computed tomography (CT) simulation is critical for precise identification of target volumes as well as critical normal structures (lung and heart). Rotational arc trajectories and individual leaf positions and weightings are then defined for each CT plane within the patient. This paper will describe the proposed rotational IMRT technique and, using simulated isodose distributions, show the improved potential for sparing of dose to the critical structures of the lung, heart, and spinal cord.« less

Long-term Effects of Large-volume Liposuction on Metabolic Risk Factors for Coronary Heart Disease

PubMed Central

Mohammed, B. Selma; Cohen, Samuel; Reeds, Dominic; Young, V. Leroy; Klein, Samuel

2009-01-01

Abdominal obesity is associated with metabolic risk factors for coronary heart disease (CHD). Although we previously found that using liposuction surgery to remove abdominal subcutaneous adipose tissue (SAT) did not result in metabolic benefits, it is possible that postoperative inflammation masked the beneficial effects. Therefore, this study provides a long-term evaluation of a cohort of subjects from our original study. Body composition and metabolic risk factors for CHD, including oral glucose tolerance, insulin resistance, plasma lipid profile, and blood pressure were evaluated in seven obese (39 ± 2 kg/m2) women before and at 10, 27, and 84–208 weeks after large-volume liposuction. Liposuction surgery removed 9.4 ± 1.8 kg of body fat (16 ± 2% of total fat mass; 6.1 ± 1.4 kg decrease in body weight), primarily from abdominal SAT; body composition and weight remained the same from 10 through 84–208 weeks. Metabolic endpoints (oral glucose tolerance, homeostasis model assessment of insulin resistance, blood pressure and plasma triglyceride (TG), high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol concentrations) obtained at 10 through 208 weeks were not different from baseline and did not change over time. These data demonstrate that removal of a large amount of abdominal SAT by using liposuction does not improve CHD metabolic risk factors associated with abdominal obesity, despite a long-term reduction in body fat. PMID:18820648

Unexpected severe calcification after transplantation of bone marrow cells in acute myocardial infarction.

PubMed

Yoon, Young-Sup; Park, Jong-Seon; Tkebuchava, Tengiz; Luedeman, Corinne; Losordo, Douglas W

2004-06-29

There has been a rapid increase in the number of clinical trials using unselected bone marrow (BM) cells or the mononuclear fraction of BM cells for treating ischemic heart diseases. Thus far, no significant deleterious effects or complications have been reported in any studies using BM-derived cells for treatment of various cardiac diseases. Seven-week-old female Fisher-344 rats underwent surgery to induce acute myocardial infarction and were randomized into 3 groups of 16 rats, each receiving intramyocardial injection of either 7x10(5) DiI-labeled total BM cells (TBMCs), the same number of DiI-labeled, clonally expanded BM multipotent stem cells, or the same volume of phosphate-buffered saline in the peri-infarct area. Echocardiography 2 weeks after cell transplantation indicated intramyocardial calcification in 4 of 14 surviving rats (28.5%) in the TBMC group. Histological examination with hematoxylin and eosin staining and von Kossa staining confirmed the presence of extensive intramyocardial calcification. Alkaline phosphatase staining revealed strong positivity surrounding the calcified area suggestive of ongoing osteogenic activity. Fluorescent microscopic examination revealed that acellular calcific areas were surrounded by DiI-labeled TBMCs, suggesting the direct involvement of transplanted TBMCs in myocardial calcification. In contrast, in hearts receiving equal volumes of saline or BM multipotent stem cells delivered in the same manner, there was no evidence of calcification. These results demonstrate that direct transplantation of unselected BM cells into the acutely infarcted myocardium may induce significant intramyocardial calcification.

Hemodynamic alterations in chronically conscious unrestrained diabetic rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbonell, L.F.; Salmon, M.G.; Garcia-Estan, J.

1987-05-01

Important cardiovascular dysfunctions have been described in streptozotocin (STZ)-diabetic rats. To determine the influence of these changes on the hemodynamic state and whether insulin treatment can avoid them, different hemodynamic parameters, obtained by the thermodilution method, were studied in STZ-induced (65 mg/kg) diabetic male Wistar rats, as well as in age-control, weight-control, and insulin-treated diabetic ones. Plasma volume was measured by dilution of radioiodinated (/sup 125/I) human serum albumin. All rats were examined in the conscious, unrestrained state 12 wk after induction of diabetes or acidified saline (pH 4.5) injection. At 12 wk of diabetic state most important findings weremore » normotension, high blood volume, bradycardia, increase in stroke volume, cardiac output, and cardiosomatic ratio, and decrease in total peripheral resistance and cardiac contractility and relaxation (dP/dt/sub max/ and dP/dt/sub min/ of left ventricular pressure curves). The insulin-treated diabetic rats did not show any hemodynamic differences when compared with the control animals. These results suggest that important hemodynamic alterations are present in the chronic diabetic states, possibly conditioning congestive heart failure. These alterations can be prevented by insulin treatment.« less

Long-Term Exposure to Ambient Air Pollution and Subclinical Cerebrovascular Disease in NOMAS (the Northern Manhattan Study).

PubMed

Kulick, Erin R; Wellenius, Gregory A; Kaufman, Joel D; DeRosa, Janet T; Kinney, Patrick L; Cheung, Ying Kuen; Wright, Clinton B; Sacco, Ralph L; Elkind, Mitchell S

2017-07-01

Long-term exposure to ambient air pollution is associated with higher risk of cardiovascular disease and stroke. We hypothesized that long-term exposure to air pollution would be associated with magnetic resonance imaging markers of subclinical cerebrovascular disease. Participants were 1075 stroke-free individuals aged ≥50 years drawn from the magnetic resonance imaging subcohort of the Northern Manhattan Study who had lived at the same residence for at least 2 years before magnetic resonance imaging. Cross-sectional associations between ambient air pollution and subclinical cerebrovascular disease were analyzed. We found an association between distance to roadway, a proxy for residential exposure to traffic pollution, and white matter hyperintensity volume; however, after adjusting for risk factors, this relationship was no longer present. All other associations between pollutant measures and white matter hyperintensity volume were null. There was no clear association between exposure to air pollutants and subclinical brain infarcts or total cerebral brain volume. We found no evidence that long-term exposure to ambient air pollution is independently associated with subclinical cerebrovascular disease in an urban population-based cohort. © 2017 American Heart Association, Inc.

Myocardial scar location as detected by cardiac magnetic resonance is associated with the outcome in heart failure patients undergoing surgical ventricular reconstruction.

PubMed

Castelvecchio, Serenella; Careri, Giulia; Ambrogi, Federico; Camporeale, Antonia; Menicanti, Lorenzo; Secchi, Francesco; Lombardi, Massimo

2018-01-01

Post-infarction myocardial scar causes adverse left ventricular remodelling and negatively affects the prognosis. We sought to investigate whether scar extent and location obtained by cardiac magnetic resonance may affect the reverse remodelling and survival of heart failure patients undergoing surgical ventricular reconstruction. From January 2011 to December 2015, 151 consecutive patients with previous myocardial infarction and left ventricular remodelling underwent surgical ventricular reconstruction at our Institution, of which 88 (58%) patients had a preoperative protocol-standardized late gadolinium enhancement (LGE)-cardiac magnetic resonance examination during the week before surgery. We excluded 40 patients with devices (26%), 15 patients with irregular heart rhythm (permanent atrial fibrillation, 10% not included in the device group) or mixed contraindications (severe claustrophobia or presence of material magnetic resonance not compatible). Among the 145 survivors, 11 patients received an implantable cardioverter defibrillator after surgery (mostly for persistent low ejection fraction) and were excluded as well, yielding a total of 59 patients (48 men, aged 65 ± 9 years) who repeated a protocol-standardized LGE-cardiac magnetic resonance examination even 6 months postoperatively and therefore represent the study population. Patients were grouped according to the presence of LGE in the antero-basal left ventricular segments (Group A) or the absence of LGE in the same segments (Group B). The postoperative left ventricular end-systolic volume index was considered the primary end-point. After surgery, left ventricular end-systolic volume index and end-diastolic volume index significantly decreased (P < 0.001, for both), while diastolic sphericity index and ejection fraction significantly increased (P = 0.015 and P < 0.001, respectively). The presence of LGE in the antero-basal left ventricular segments (10 patients, Group A) was the only independent predictor of outcome (P = 0.02) at multivariate analysis, being the postoperative left ventricular end-systolic volume index significantly higher compared to that of patients of Group B (49 patients) (78 ± 26 ml/m2 vs 55 ± 20 ml/m2, P = 0.003). Furthermore, patients with a postoperative left ventricular end-systolic volume index >60 ml/m2 showed a higher risk of cardiac events (hazard ratio = 3.67, P = 0.02). In patients undergoing surgical ventricular reconstruction, LGE scar location affects the left ventricular reverse remodelling, which in turn might limit the survival benefit. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Total Artificial Heart Bridge to Transplantation for a Patient With Occult Intracardiac Malignancy: Case Report.

PubMed

Reich, H; Czer, L; Bannykh, S; De Robertis, M; Wolin, E; Amersi, F; Moriguchi, J; Kobashigawa, J; Arabia, F

2015-09-01

Malignancy is the leading cause of long-term morbidity and mortality after heart and other solid organ transplantation; therefore, great emphasis is placed on pre- and post-transplantation cancer screening. Even with meticulous screening during evaluation for heart transplant candidacy, an occult cancer may not be apparent. Here, we share the case of a 51-year-old man with refractory heart failure who underwent total artificial heart implantation as a bridge to transplantation with the surprise finding of an isolated deposit of metastatic carcinoid tumor nested within a left ventricular papillary muscle in his explanted heart. The primary ileal carcinoid tumor was identified and resected completely. After remaining cancer-free for 14 months, he was listed for heart transplantation and was transplanted 2 months later. He is currently 3.5 months out from heart transplantation and doing well, without evidence of recurring malignancy. Copyright © 2015 Elsevier Inc. All rights reserved.

Elevated levels of psychophysiological arousal and cortisol in patients with somatization syndrome.

PubMed

Rief, W; Shaw, R; Fichter, M M

1998-01-01

This study investigates psychological and psychobiological processes in patients with somatization syndrome. We compared physiological measures (heart rate, finger pulse volume, electrodermal activity, electromyography), cortisol levels, and subjective well-being during rest and during a mental stress task as well as selective attention and memory for illness-related words in 58 patients with somatization syndrome and 21 healthy controls. The somatization group had higher morning salivary cortisol concentrations, higher heart rates, and lower levels of finger pulse volume. During the mental stress task, patients with somatization syndrome felt more distressed and had higher heart rates, whereas controls showed habituation to the experimental situation. We were unable to demonstrate an attention or memory bias specific for somatization. The results point to several psychological, psychophysiological, and psychobiological mechanisms that might be involved in the maintenance of somatization syndrome. These results are discussed from a cognitive-psychobiological perspective.

Metformin and phenformin activate AMP-activated protein kinase in the heart by increasing cytosolic AMP concentration.

PubMed

Zhang, Li; He, Huamei; Balschi, James A

2007-07-01

AMP-activated protein kinase (AMPK) acts as a cellular energy sensor: it responds to an increase in AMP concentration ([AMP]) or the AMP-to-ATP ratio (AMP/ATP). Metformin and phenformin, which are biguanides, have been reported to increase AMPK activity without increasing AMP/ATP. This study tests the hypothesis that these biguanides increase AMPK activity in the heart by increasing cytosolic [AMP]. Groups of isolated rat hearts (n = 5-7 each) were perfused with Krebs-Henseleit buffer with or without 0.2 mM phenformin or 10 mM metformin, and (31)P-NMR-measured phosphocreatine, ATP, and intracellular pH were used to calculate cytosolic [AMP]. At various times, hearts were freeze-clamped and assayed for AMPK activity, phosphorylation of Thr(172) on AMPK-alpha, and phosphorylation of Ser(79) on acetyl-CoA carboxylase, an AMPK target. In hearts treated with phenformin for 18 min and then perfused for 20 min with Krebs-Henseleit buffer, [AMP] began to increase at 26 min and AMPK activity was elevated at 36 min. In hearts treated with metformin, [AMP] was increased at 50 min and AMPK activity, phosphorylated AMPK, and phosphorylated acetyl-CoA carboxylase were elevated at 61 min. In metformin-treated hearts, HPLC-measured total AMP content and total AMP/ATP did not increase. In summary, phenformin and metformin increase AMPK activity and phosphorylation in the isolated heart. The increase in AMPK activity was always preceded by and correlated with increased cytosolic [AMP]. Total AMP content and total AMP/ATP did not change. Cytosolic [AMP] reported metabolically active AMP, which triggered increased AMPK activity, but measures of total AMP did not.

Temporal Evaluation of Cardiac Myocyte Hypertrophy and Hyperplasia in Male Rats Secondary to Chronic Volume Overload

PubMed Central

Du, Yan; Plante, Eric; Janicki, Joseph S.; Brower, Gregory L.

2010-01-01

The temporal myocardial remodeling induced by chronic ventricular volume overload in male rats was examined. Specifically, left ventricular (LV) cardiomyocyte length and width, sarcomere length, and number of nuclei were measured in male rats (n = 8 to 17) at 1, 3, 5, 7, 21, 35, and 56 days after creation of an infrarenal aortocaval fistula. In contrast to previously published reports of progressive increases in cardiomyocyte length and cross-sectional area at 5 days post-fistula and beyond in female hearts, cardiomyocyte length and width did not increase significantly in males during the first 35 days of volume overload. Furthermore, a significant decrease in cardiomyocyte length relative to age-matched controls, together with a reduced number of sarcomeres per cell, was noted in male hearts at 5 days post-fistula. There was a concurrent increase in the percentage of mononucleated cardiomyocytes from 11.6% to 18% at 5 days post-fistula. These initial differences could not be attributed to cardiomyocyte proliferation, and treatment with a microtubule stabilizing agent prevented them from occurring. The subsequent significant increase in LV weight without corresponding increases in cardiomyocyte dimensions is indicative of hyperplasia. Thus, these findings indicate hyperplasia resulting from cytokinesis of cardiomyocytes is a key mechanism, independent of hypertrophy, that contributes to the significant increase in LV mass in male hearts subjected to chronic volume overload. PMID:20651227

Denoising and 4D visualization of OCT images

PubMed Central

Gargesha, Madhusudhana; Jenkins, Michael W.; Rollins, Andrew M.; Wilson, David L.

2009-01-01

We are using Optical Coherence Tomography (OCT) to image structure and function of the developing embryonic heart in avian models. Fast OCT imaging produces very large 3D (2D + time) and 4D (3D volumes + time) data sets, which greatly challenge ones ability to visualize results. Noise in OCT images poses additional challenges. We created an algorithm with a quick, data set specific optimization for reduction of both shot and speckle noise and applied it to 3D visualization and image segmentation in OCT. When compared to baseline algorithms (median, Wiener, orthogonal wavelet, basic non-orthogonal wavelet), a panel of experts judged the new algorithm to give much improved volume renderings concerning both noise and 3D visualization. Specifically, the algorithm provided a better visualization of the myocardial and endocardial surfaces, and the interaction of the embryonic heart tube with surrounding tissue. Quantitative evaluation using an image quality figure of merit also indicated superiority of the new algorithm. Noise reduction aided semi-automatic 2D image segmentation, as quantitatively evaluated using a contour distance measure with respect to an expert segmented contour. In conclusion, the noise reduction algorithm should be quite useful for visualization and quantitative measurements (e.g., heart volume, stroke volume, contraction velocity, etc.) in OCT embryo images. With its semi-automatic, data set specific optimization, we believe that the algorithm can be applied to OCT images from other applications. PMID:18679509

Cerebral venous circulatory system evaluation by ultrasonography.

PubMed

Zavoreo, Iris; Basić-Kes, Vanja; Zadro-Matovina, Lucija; Lisak, Marijana; Corić, Lejla; Cvjeticanin, Timon; Ciliga, Dubravka; Bobić, Tatjana Trost

2013-06-01

Venous system can be classified as pulmonary veins, systemic veins and venous sinuses that are present only within the skull. Cerebral venous system is divided into two main parts, the superficial and the deep system. The main assignment of veins is to carry away deoxygenated blood and other maleficient materials from the tissues towards the heart. Veins have thinner walls and larger lumina than arteries. Between 60% and 70% of the total blood volume is found in veins. The major factors that influence venous function are the respiratory cycle, venous tone, the function of the right heart, gravity, and the muscle pump. Venous system, in general, can be presented by selective venography, Doppler sonography, computed tomography (CT) venography and magnetic resonance (MR) venography, and cerebral venous system can be displayed by selective venography, cerebral CT venography, cerebral MR venography, and specialized extracranial and transcranial Doppler sonography. The aim of this paper is to show the possibilities of intracranial and extracranial ultrasound evaluation of the head and neck venous circulation and chronic cerebrospinal venous insufficiency as one of the most common pathologies evaluated as part of neurodegenerative processes in the central nervous system.

Artificial heart development program. Volume I. System development. Phase III summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-01-01

The report documents efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power systems portion is physically that portion of the implantable model between the Pu-238 heat sources and the blood pump ventricles. The work performed had two parallel themes. The first of these was the development of an integrated implantable model for bench and animal experiments plus design effort on a more advanced model. The second was research andmore » development on components of the system done in conjunction with the development of the implantable model and to provide technology for incorporation into advanced models plus support to implantations, at the University of Utah, of the systems blood pumping elements when driven by electric motor. The efforts and results of implantable model development are covered, mainly, in the text of the report. The research and development efforts and results are reported, primarily, in the appendices (Vol. 2).« less

Cardiopoietic cell therapy for advanced ischaemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial.

PubMed

Bartunek, Jozef; Terzic, Andre; Davison, Beth A; Filippatos, Gerasimos S; Radovanovic, Slavica; Beleslin, Branko; Merkely, Bela; Musialek, Piotr; Wojakowski, Wojciech; Andreka, Peter; Horvath, Ivan G; Katz, Amos; Dolatabadi, Dariouch; El Nakadi, Badih; Arandjelovic, Aleksandra; Edes, Istvan; Seferovic, Petar M; Obradovic, Slobodan; Vanderheyden, Marc; Jagic, Nikola; Petrov, Ivo; Atar, Shaul; Halabi, Majdi; Gelev, Valeri L; Shochat, Michael K; Kasprzak, Jaroslaw D; Sanz-Ruiz, Ricardo; Heyndrickx, Guy R; Nyolczas, Noémi; Legrand, Victor; Guédès, Antoine; Heyse, Alex; Moccetti, Tiziano; Fernandez-Aviles, Francisco; Jimenez-Quevedo, Pilar; Bayes-Genis, Antoni; Hernandez-Garcia, Jose Maria; Ribichini, Flavio; Gruchala, Marcin; Waldman, Scott A; Teerlink, John R; Gersh, Bernard J; Povsic, Thomas J; Henry, Timothy D; Metra, Marco; Hajjar, Roger J; Tendera, Michal; Behfar, Atta; Alexandre, Bertrand; Seron, Aymeric; Stough, Wendy Gattis; Sherman, Warren; Cotter, Gad; Wijns, William

2017-03-01

Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort. This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein-Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann-Whitney estimator 0.54, 95% confidence interval [CI] 0.47-0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200-370 mL (60% of patients) (Mann-Whitney estimator 0.61, 95% CI 0.52-0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death. The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Respiratory uncoupling by increased H(+) or K(+) flux is beneficial for heart mitochondrial turnover of reactive oxygen species but not for permeability transition.

PubMed

Morota, Saori; Piel, Sarah; Hansson, Magnus J

2013-09-22

Ischemic preconditioning has been proposed to involve changes in mitochondrial H(+) and K(+) fluxes, in particular through activation of uncoupling proteins and ATP-sensitive K(+) channels (MitoKATP). The objectives of the present study were to explore how increased H(+) and K(+) fluxes influence heart mitochondrial physiology with regard to production and scavenging of reactive oxygen species (ROS), volume changes and resistance to calcium-induced mitochondrial permeability transition (mPT). Isolated rat heart mitochondria were exposed to a wide concentration range of the protonophore CCCP or the potassium ionophore valinomycin to induce increased H(+) and K(+) conductance, respectively. Simultaneous monitoring of mitochondrial respiration and calcium retention capacity (CRC) demonstrated that the relative increase in respiration caused by valinomycin or CCCP correlated with a decrease in CRC, and that no level of respiratory uncoupling was associated with enhanced resistance to mPT. Mitochondria suspended in hyperosmolar buffer demonstrated a dose-dependent reduction in CRC with increasing osmolarity. However, mitochondria in hypoosmolar buffer to increase matrix volume did not display increased CRC. ROS generation was reduced by both K(+)- and H(+)-mediated respiratory uncoupling. The ability of heart mitochondria to detoxify H2O2 was substantially greater than the production rate. The H2O2 detoxification was dependent on respiratory substrates and was dramatically decreased following calcium-induced mPT, but was unaffected by uncoupling via increased K(+) and H(+) conductance. It is concluded that respiratory uncoupling is not directly beneficial to rat heart mitochondrial resistance to calcium overload irrespective of whether H(+) or K(+) conductance is increased. The negative effects of respiratory uncoupling thus probably outweigh the reduction in ROS generation and a potential positive effect by increased matrix volume, resulting in a net sensitization of heart mitochondria to mPT activation.

Cardiopoietic cell therapy for advanced ischaemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

PubMed Central

Bartunek, Jozef; Terzic, Andre; Davison, Beth A.; Filippatos, Gerasimos S.; Radovanovic, Slavica; Beleslin, Branko; Merkely, Bela; Musialek, Piotr; Wojakowski, Wojciech; Andreka, Peter; Horvath, Ivan G.; Katz, Amos; Dolatabadi, Dariouch; El Nakadi, Badih; Arandjelovic, Aleksandra; Edes, Istvan; Seferovic, Petar M.; Obradovic, Slobodan; Vanderheyden, Marc; Jagic, Nikola; Petrov, Ivo; Atar, Shaul; Halabi, Majdi; Gelev, Valeri L.; Shochat, Michael K.; Kasprzak, Jaroslaw D.; Sanz-Ruiz, Ricardo; Heyndrickx, Guy R.; Nyolczas, Noémi; Legrand, Victor; Guédès, Antoine; Heyse, Alex; Moccetti, Tiziano; Fernandez-Aviles, Francisco; Jimenez-Quevedo, Pilar; Bayes-Genis, Antoni; Hernandez-Garcia, Jose Maria; Ribichini, Flavio; Gruchala, Marcin; Waldman, Scott A.; Teerlink, John R.; Gersh, Bernard J.; Povsic, Thomas J.; Henry, Timothy D.; Metra, Marco; Hajjar, Roger J.; Tendera, Michal; Behfar, Atta; Alexandre, Bertrand; Seron, Aymeric; Stough, Wendy Gattis; Sherman, Warren; Cotter, Gad; Wijns, William

2017-01-01

Aims Cardiopoietic cells, produced through cardiogenic conditioning of patients’ mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort. Methods and results This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein–Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann–Whitney estimator 0.54, 95% confidence interval [CI] 0.47–0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200–370 mL (60% of patients) (Mann–Whitney estimator 0.61, 95% CI 0.52–0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death. Conclusion The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted. PMID:28025189

Effect of Leukocyte Telomere Length on Total and Regional Brain Volumes in a Large Population-Based Cohort

PubMed Central

King, Kevin S.; Kozlitina, Julia; Rosenberg, Roger N.; Peshock, Ronald M.; McColl, Roderick W.; Garcia, Christine K.

2017-01-01

Importance Telomere length has been associated with dementia and psychological stress, but its relationship with human brain size is unknown. Objective To determine if peripheral blood telomere length is associated with brain volume. Design, Setting, and Participants Peripheral blood leukocyte telomere length and brain volumes were measured for 1960 individuals in the Dallas Heart Study, a population-based, probability sample of Dallas County, Texas, residents, with a median (25th-75th percentile) age of 50 (42-58) years. Global and 48 regional brain volumes were assessed from the automated analysis of magnetic resonance imaging. Main Outcomes and Measures Telomere length and global and regional brain volumes. Results Leukocyte telomere length was associated with total cerebral volume (β [SE], 0.06 [0.01], P <.001) including white and cortical gray matter volume (β [SE], 0.04 [0.01], P = .002; β [SE], 0.07 [0.02], P <.001, respectively), independent of age, sex, ethnicity, and total intracranial volume. While age was associated with the size of most subsegmental regions of the cerebral cortex, telomere length was associated with certain subsegmental regions. Compared with age, telomere length (TL) explained a sizeable proportion of the variance in volume of the hippocampus, amygdala, and inferior temporal region (hippocampus: βTL [SE], 0.08 [0.02], R2, 0.91% vs βage [SE], −0.16 [0.02], R2, 3.80%; amygdala: βTL [SE], 0.08 [0.02], R2, 0.78% vs βage [SE], −0.19 [0.02], R2,4.63%; inferior temporal: βTL [SE], 0.07 [0.02], R2, 0.92% vs βage [SE], −0.14 [0.02], R2, 3.98%) (P <.001 for all). The association of telomere length and the size of the inferior and superior parietal, hippocampus, and fusiform regions was stronger in individuals older than 50 years than younger individuals (inferior parietal: β>50 [SE], 0.13 [0.03], P <.001 vs β≤50 [SE], 0.02 [0.02], P = .51, P for interaction = .001; superior parietal: β>50 [SE], 0.11 [0.03], P <.001 vs β≤50 [SE], 0.01 [0.02], P = .71, P for interaction = .004; hippocampus: β>50 [SE], 0.10 [0.03], P = .004 vs β≤50 [SE], 0.05 [0.02], P = .07, P for interaction = .04; fusiform: β>50 [SE], 0.09 [0.03], P = .002, β≤50 [SE], 0.03 [0.02], P = .31, P for interaction = .03). The volume of the hippocampus, amygdala, superior and inferior temporal, precuneus, lateral orbitofrontal, posterior cingulate, thalamus and ventral diencephalon were independently associated with telomere length after adjustment for all covariates (age, gender, ethnicity, total intracranial volume, body mass index, blood pressure, diabetes, smoking status, and APOE genotype). Conclusions and Relevance To our knowledge, this is the first population-based study to date to evaluate telomere length as an independent predictor of global and regional brain size. Future studies are needed to determine how telomere length and anatomic structural changes are related to cognitive function, dementia, and psychological disease. PMID:25090243

[Effects of low-dose insulin on oxidation-reduction in rat organs after major burns].

PubMed

Wang, Wei; Jiang, Hong-mei; Li, Wei-ren; Zuo, Lu; Tao, Lei; Yu, Xiang

2013-11-12

To explore the effects of low-dose insulin on oxidation-reduction of heart and kidney in rats immediately after severe burns. Twenty four male Sprague-Dawley (SD) rats were randomly divided into 3 groups of sham burn, burn and treatment (n = 8 each). The sham burn group was placed into 37 °C warm water for 15 seconds to simulate burn process and received no fluid replacement. The burn and treatment groups were immersed into (95 ± 0.5) °C hot water for 15 seconds to make a rat model of 30% total burn surface area, III degree burn injury and immediately received an intraperitoneal injection of physiological saline (40 ml/kg). At the same time, a subcutaneous injection of insulin (1.0 U×kg(-1)×d(-1)) was given in the treatment group and a subcutaneous injection of same-volume physiological saline in the burn group. The rats were sacrificed after 24 post-scald hours (PSH). Abdominal aortic blood was collected for an analysis of blood glucose. The oxidation and antioxidation parameters of heart and kidney, such as malondialdehyde (MDA), xanthine oxidase (XO), myeloperoxidase (MPO), total superoxide dismutase (T-SOD), superoxide dismutase 1, 2 (SOD1, 2), catalase (CAT) and glutathione peroxidase (GPx), were detected by spectrophotometry. Compared with the sham burn group, MDA content, XO and MPO activities of heart and kidney were significantly higher in the burn group (all P < 0.05); in the treatment group, MDA content and XO activity of heart were significantly lower than the burn group ((0.85 ± 0.07) vs (1.11 ± 0.07) nmol/mg, (69.72 ± 1.94) vs (77.21 ± 2.10) U/g) while the MPO activities of heart and kidney were significantly lower (all P < 0.05).compared with the sham burn group, the activities of T-SOD, CAT, GPx of heart and kidney were significantly lower in the burn group, SOD1 activity of kidney was significantly lower, but SOD2 activity of kidney was significantly higher while SOD2 activity of heart was significantly lower (all P < 0.05); Compared with the burn group, the activities of T-SOD and SOD1 of heart in the treatment group were significantly higher ((83.5 ± 2.5) vs (79.6 ± 3.2), (62.8 ± 2.3) vs (58.8 ± 3.0) U/mg), CAT and GPx activity of heart and kidney were significantly higher (all P < 0.05). Compared with the sham burn group, blood glucose in the burn and treatment group were significantly higher ((7.81 ± 0.30), (7.19 ± 0.22) vs (6.30 ± 0.24) mmol/L) and blood glucose in the treatment group was significantly lower than the burn group((7.81 ± 0.30) mmol/L)(all P < 0.05). During an early stage, a low-dose insulin may intervene in heart tissue lipid peroxidation of severely burned rats. And differences exist in the effects of oxidation-reduction between heart and kidney.

Development and Validation of a Heart Atlas to Study Cardiac Exposure to Radiation Following Treatment for Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Mary, E-mail: maryfeng@umich.ed; Moran, Jean M.; Koelling, Todd

2011-01-01

Purpose: Cardiac toxicity is an important sequela of breast radiotherapy. However, the relationship between dose to cardiac structures and subsequent toxicity has not been well defined, partially due to variations in substructure delineation, which can lead to inconsistent dose reporting and the failure to detect potential correlations. Here we have developed a heart atlas and evaluated its effect on contour accuracy and concordance. Methods and Materials: A detailed cardiac computed tomography scan atlas was developed jointly by cardiology, cardiac radiology, and radiation oncology. Seven radiation oncologists were recruited to delineate the whole heart, left main and left anterior descending interventricularmore » branches, and right coronary arteries on four cases before and after studying the atlas. Contour accuracy was assessed by percent overlap with gold standard atlas volumes. The concordance index was also calculated. Standard radiation fields were applied. Doses to observer-contoured cardiac structures were calculated and compared with gold standard contour doses. Pre- and post-atlas values were analyzed using a paired t test. Results: The cardiac atlas significantly improved contour accuracy and concordance. Percent overlap and concordance index of observer-contoured cardiac and gold standard volumes were 2.3-fold improved for all structures (p < 0.002). After application of the atlas, reported mean doses to the whole heart, left main artery, left anterior descending interventricular branch, and right coronary artery were within 0.1, 0.9, 2.6, and 0.6 Gy, respectively, of gold standard doses. Conclusions: This validated University of Michigan cardiac atlas may serve as a useful tool in future studies assessing cardiac toxicity and in clinical trials which include dose volume constraints to the heart.« less

Geographic Variations in Incremental Costs of Heart Disease Among Medicare Beneficiaries, by Type of Service, 2012.

PubMed

Wakim, Rita; Ritchey, Matthew; Hockenberry, Jason; Casper, Michele

2016-12-29

Using 2012 data on fee-for-service Medicare claims, we documented regional and county variation in incremental standardized costs of heart disease (ie, comparing costs between beneficiaries with heart disease and beneficiaries without heart disease) by type of service (eg, inpatient, outpatient, post-acute care). Absolute incremental total costs varied by region. Although the largest absolute incremental total costs of heart disease were concentrated in southern and Appalachian counties, geographic patterns of costs varied by type of service. These data can be used to inform development of policies and payment models that address the observed geographic disparities.

Assessing cardiac function from total-variation-regularized 4D C-arm CT in the presence of angular undersampling

NASA Astrophysics Data System (ADS)

Taubmann, O.; Haase, V.; Lauritsch, G.; Zheng, Y.; Krings, G.; Hornegger, J.; Maier, A.

2017-04-01

Time-resolved tomographic cardiac imaging using an angiographic C-arm device may support clinicians during minimally invasive therapy by enabling a thorough analysis of the heart function directly in the catheter laboratory. However, clinically feasible acquisition protocols entail a highly challenging reconstruction problem which suffers from sparse angular sampling of the trajectory. Compressed sensing theory promises that useful images can be recovered despite massive undersampling by means of sparsity-based regularization. For a multitude of reasons—most notably the desired reduction of scan time, dose and contrast agent required—it is of great interest to know just how little data is actually sufficient for a certain task. In this work, we apply a convex optimization approach based on primal-dual splitting to 4D cardiac C-arm computed tomography. We examine how the quality of spatially and temporally total-variation-regularized reconstruction degrades when using as few as 6.9+/- 1.2 projection views per heart phase. First, feasible regularization weights are determined in a numerical phantom study, demonstrating the individual benefits of both regularizers. Secondly, a task-based evaluation is performed in eight clinical patients. Semi-automatic segmentation-based volume measurements of the left ventricular blood pool performed on strongly undersampled images show a correlation of close to 99% with measurements obtained from less sparsely sampled data.

New Stethoscope With Extensible Diaphragm.

PubMed

Takashina, Tsunekazu; Shimizu, Masashi; Muratake, Torakazu; Mayuzumi, Syuichi

2016-08-25

This study compared the diagnostic efficacy of the common suspended diaphragm stethoscope (SDS) with a new extensible diaphragm stethoscope (EDS) for low-frequency heart sounds. The EDS was developed by using an ethylene propylene diene monomer diaphragm. The results showed that the EDS enhanced both the volume and quality of low-frequency heart sounds, and improved the ability of examiners to auscultate such heart sounds. Based on the results of the sound analysis, the EDS is more efficient than the SDS. (Circ J 2016; 80: 2047-2049).

Plasma Biomarkers Reflecting Profibrotic Processes in Heart Failure With a Preserved Ejection Fraction: Data From the Prospective Comparison of ARNI With ARB on Management of Heart Failure With Preserved Ejection Fraction Study.

PubMed

Zile, Michael R; Jhund, Pardeep S; Baicu, Catalin F; Claggett, Brian L; Pieske, Burkert; Voors, Adriaan A; Prescott, Margaret F; Shi, Victor; Lefkowitz, Martin; McMurray, John J V; Solomon, Scott D

2016-01-01

Heart failure with preserved ejection fraction is a clinical syndrome that has been associated with changes in the extracellular matrix. The purpose of this study was to determine whether profibrotic biomarkers accurately reflect the presence and severity of disease and underlying pathophysiology and modify response to therapy in patients with heart failure with preserved ejection fraction. Four biomarkers, soluble form of ST2 (an interleukin-1 receptor family member), galectin-3, matrix metalloproteinase-2, and collagen III N-terminal propeptide were measured in the Prospective Comparison of ARNI With ARB on Management of Heart Failure With Preserved Ejection Fraction (PARAMOUNT) trial at baseline, 12 and 36 weeks after randomization to valsartan or LCZ696. We examined the relationship between baseline biomarkers, demographic and echocardiographic characteristics, change in primary (change in N-terminal pro B-type natriuretic peptide) and secondary (change in left atrial volume) end points. The median (interquartile range) value for soluble form of ST2 (33 [24.6-48.1] ng/mL) and galectin 3 (17.8 [14.1-22.8] ng/mL) were higher, and for matrix metalloproteinase-2 (188 [155.5-230.6] ng/mL) lower, than in previously published referent controls; collagen III N-terminal propeptide (5.6 [4.3-6.9] ng/mL) was similar to referent control values. All 4 biomarkers correlated with severity of disease as indicated by N-terminal pro B-type natriuretic peptide, E/E', and left atrial volume. Baseline biomarkers did not modify the response to LCZ696 for lowering N-terminal pro B-type natriuretic peptide; however, left atrial volume reduction varied by baseline level of soluble form of ST2 and galectin 3; patients with values less than the observed median (<33 ng/mL soluble form of ST2 and <17.8 ng/mL galectin 3) had reduction in left atrial volume, those above median did not. Although LCZ696 reduced N-terminal pro B-type natriuretic peptide, levels of the other 4 biomarkers were not affected over time. In patients with heart failure with preserved ejection fraction, biomarkers that reflect collagen homeostasis correlated with the presence and severity of disease and underlying pathophysiology, and may modify the structural response to treatment. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00887588. © 2016 American Heart Association, Inc.

Predicted Hemodynamic Benefits Of Counterpulsation Therapy Using A Superficial Surgical Approach

PubMed Central

Giridharan, Guruprasad A.; Pantalos, George M.; Litwak, Kenneth N.; Spence, Paul A.; Koenig, Steven C.

2010-01-01

A volume-displacement counterpulsation device (CPD) intended for chronic implantation via a superficial surgical approach is proposed. The CPD is a pneumatically driven sac that fills during native heart systole and empties during diastole through a single, valveless cannula anastomosed to the subclavian artery. Computer simulation was performed to predict and compare the physiological responses of the CPD to the intraaortic balloon pump (IABP) in a clinically relevant model of early stage heart failure. The effect of device stroke volume (0–50 ml) and control modes (timing, duration, morphology) on landmark hemodynamic parameters and the LV pressure–volume relationship were investigated. Simulation results predicted that the CPD would provide hemodynamic benefits comparable to an IABP as evidenced by up to 25% augmentation of peak diastolic aortic pressure, which increases diastolic coronary perfusion by up to 34%. The CPD may also provide up to 34% reduction in LV end-diastolic pressure and 12% reduction in peak systolic aortic pressure, lowering LV workload by up to 26% and increasing cardiac output by up to 10%. This study demonstrated that the superficial CPD technique may be used acutely to achieve similar improvements in hemodynamic function as the IABP in early stage heart failure patients. PMID:16436889

Occult constrictive pericardial disease emerging 40 years after chest radiation therapy: a case report.

PubMed

Goten, Chiaki; Murai, Hisayoshi; Takashima, Shin-Ichiro; Kato, Takeshi; Usui, Soichiro; Furusho, Hiroshi; Saeki, Takahiro; Sakagami, Satoru; Takemura, Hirofumi; Kaneko, Shuichi; Takamura, Masayuki

2018-05-31

The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert disease in which CP is manifested in a condition of volume overload. A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication. This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.

Cardiovascular adaptation to extrauterine life after intrauterine growth restriction.

PubMed

Rodriguez-Guerineau, Luciana; Perez-Cruz, Miriam; Gomez Roig, María D; Cambra, Francisco J; Carretero, Juan; Prada, Fredy; Gómez, Olga; Crispi, Fátima; Bartrons, Joaquim

2018-02-01

Introduction The adaptive changes of the foetal heart in intrauterine growth restriction can persist postnatally. Data regarding its consequences for early circulatory adaptation to extrauterine life are scarce. The aim of this study was to assess cardiac morphometry and function in newborns with late-onset intrauterine growth restriction to test the hypothesis that intrauterine growth restriction causes cardiac shape and functional changes at birth. A comprehensive echocardiographic study was performed in 25 neonates with intrauterine growth restriction and 25 adequate-for-gestational-age neonates. Compared with controls, neonates with intrauterine growth restriction had more globular ventricles, lower longitudinal tricuspid annular motion, and higher left stroke volume without differences in the heart rate. Neonates with intrauterine growth restriction also showed subclinical signs of diastolic dysfunction in the tissue Doppler imaging with lower values of early (e') diastolic annular peak velocities in the septal annulus. Finally, the Tei index in the tricuspid annulus was higher in the intrauterine growth restriction group. Neonates with history of intrauterine growth restriction showed cardiac remodelling and signs of systolic and diastolic dysfunction. Overall, there was a significant tendency to worse cardiac function results in the right heart. The adaptation to extrauterine life occurred with more globular hearts, higher stroke volumes but a similar heart rate compared to adequate-for-gestational-age neonates.

A mock heart engineered with helical aramid fibers for in vitro cardiovascular device testing.

PubMed

Jansen-Park, So-Hyun; Hsu, Po-Lin; Müller, Indra; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas

2017-04-01

Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters. Ventricle and aorta molds were produced based on MRI data and cast with silicone. Aramid fibers were layered in the silicone ventricle to reproduce ventricle torsion. A rotating hollow shaft was connected to the apex enabling the rotation of the MH and the connection of a VAD. Silicone wall thickness, aramid fiber angle and fiber pitch were varied to generate different MH models. All MH models were placed in a tank filled with variable amounts of water and air simulating the compliance. In this work, physiological ventricular torsion angles (15°-26°) and physiological pressure-volume loops were achieved. This MHCL can serve as a comprehensive testing platform for cardiovascular devices, such as artificial heart valves and cannulation of VADs.

[Obesity and heart failure].

PubMed

Weismann, D; Wiedmann, S; Bala, M; Frantz, S; Fassnacht, M

2015-02-01

Obesity is an important risk factor for the development of heart failure. In normotensive obese patients, a reduced peripheral resistance is typically observed and is accompanied by an increased fluid volume and an increase in cardiac work, resulting in hypertrophy and diastolic heart failure, which can be visualized with echocardiography. However, in the presence of arterial hypertension cardiac geometry is not different to hypertensive heart disease without obesity. Furthermore, the typical changes found with obesity, such as reduced peripheral resistance and increased blood volume, are no longer present. Obstructive sleep apnea (OSA) is very common in obesity and warrants screening but levels of the heart failure marker N-terminal pro-brain natriuretic peptide (NT-ProBNP) might be misleading as the values are lower in obesity than in normal weight controls. Body weight reduction is advisable but difficult to achieve and much more difficult to maintain. Furthermore, diet and exercise has not been proven to enhance life expectancy in obesity. However, with bariatric surgery, long-term weight reduction can be achieved and mortality can be reduced. With effective weight loss and improved clinical outcome after bariatric surgery, treatment of obesity has shifted much more into focus. Regardless of technical challenges in the work-up of obese patients, clinical symptoms suggestive of cardiac disorders warrant prompt investigation with standard techniques following recommendations as established for normal weight patients.

Heart failure: when form fails to follow function.

PubMed

Katz, Arnold M; Rolett, Ellis L

2016-02-01

Cardiac performance is normally determined by architectural, cellular, and molecular structures that determine the heart's form, and by physiological and biochemical mechanisms that regulate the function of these structures. Impaired adaptation of form to function in failing hearts contributes to two syndromes initially called systolic heart failure (SHF) and diastolic heart failure (DHF). In SHF, characterized by high end-diastolic volume (EDV), the left ventricle (LV) cannot eject a normal stroke volume (SV); in DHF, with normal or low EDV, the LV cannot accept a normal venous return. These syndromes are now generally defined in terms of ejection fraction (EF): SHF became 'heart failure with reduced ejection fraction' (HFrEF) while DHF became 'heart failure with normal or preserved ejection fraction' (HFnEF or HFpEF). However, EF is a chimeric index because it is the ratio between SV--which measures function, and EDV--which measures form. In SHF the LV dilates when sarcomere addition in series increases cardiac myocyte length, whereas sarcomere addition in parallel can cause concentric hypertrophy in DHF by increasing myocyte thickness. Although dilatation in SHF allows the LV to accept a greater venous return, it increases the energy cost of ejection and initiates a vicious cycle that contributes to progressive dilatation. In contrast, concentric hypertrophy in DHF facilitates ejection but impairs filling and can cause heart muscle to deteriorate. Differences in the molecular signals that initiate dilatation and concentric hypertrophy can explain why many drugs that improve prognosis in SHF have little if any benefit in DHF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

A step-wise approach for analysis of the mouse embryonic heart using 17.6 Tesla MRI

PubMed Central

Gabbay-Benziv, Rinat; Reece, E. Albert; Wang, Fang; Bar-Shir, Amnon; Harman, Chris; Turan, Ozhan M.; Yang, Peixin; Turan, Sifa

2018-01-01

Background The mouse embryo is ideal for studying human cardiac development. However, laboratory discoveries do not easily translate into clinical findings partially because of histological diagnostic techniques that induce artifacts and lack standardization. Aim To present a step-wise approach using 17.6 T MRI, for evaluation of mice embryonic heart and accurate identification of congenital heart defects. Subjects 17.5-embryonic days embryos from low-risk (non-diabetic) and high-risk (diabetic) model dams. Study design Embryos were imaged using 17.6 Tesla MRI. Three-dimensional volumes were analyzed using ImageJ software. Outcome measures Embryonic hearts were evaluated utilizing anatomic landmarks to locate the four-chamber view, the left- and right-outflow tracts, and the arrangement of the great arteries. Inter- and intra-observer agreement were calculated using kappa scores by comparing two researchers’ evaluations independently analyzing all hearts, blinded to the model, on three different, timed occasions. Each evaluated 16 imaging volumes of 16 embryos: 4 embryos from normal dams, and 12 embryos from diabetic dams. Results Inter-observer agreement and reproducibility were 0.779 (95% CI 0.653–0.905) and 0.763 (95% CI 0.605–0.921), respectively. Embryonic hearts were structurally normal in 4/4 and 7/12 embryos from normal and diabetic dams, respectively. Five embryos from diabetic dams had defects: ventricular septal defects (n = 2), transposition of great arteries (n = 2) and Tetralogy of Fallot (n = 1). Both researchers identified all cardiac lesions. Conclusion A step-wise approach for analysis of MRI-derived 3D imaging provides reproducible detailed cardiac evaluation of normal and abnormal mice embryonic hearts. This approach can accurately reveal cardiac structure and, thus, increases the yield of animal model in congenital heart defect research. PMID:27569369

The total artificial heart.

PubMed

Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

2015-12-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart.

PubMed

Yeo, Lami; Romero, Roberto

2013-09-01

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology. We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum). In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy. The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify examination of the fetal heart and reduce operator dependency. The observation of abnormal echocardiography views in the diagnostic planes and/or VIS-Assistance® should raise the index of suspicion for congenital heart disease. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Immediate central and peripheral haemodynamic effects of a new vasodilating agent Pinacidil (P1134) in hypertensive man.

PubMed

Carlsen, J E; Kardel, T; Hilden, T; Tangø, M; Trap-Jensen, J

1981-08-01

The purpose of this study was to evaluate the immediate central and peripheral haemodynamic effects of a new vasodilating agent P 1134, in hypertensive man. After oral administration of 25 mg P 1134, the maximal haemodynamic changes were (mean +/- 1 SEM): mean blood pressure fell from 121.8 +/- 6.5 to 80.5 +/- 7.8 mmHg, heart rate increased 24.2 +/- 4.5 beats/min, cardiac output rose 2.9 +/- 0.3 1/min and forearm blood flow increased 1.0 +/- 0.1 ml/100 ml tissue/min. Stroke volume increased 17.0 +/- 2.1 ml and the inotropic state of the heart as judged from systolic time intervals increased. Total peripheral resistance and forearm vascular resistance were both reduced by approx. 50%. Linear correlations were found between the serum concentration of P 1134 and the change in mean blood pressure and total peripheral resistance. Changes in the other parameters mentioned above occurred progressively with changes in mean blood pressure and total peripheral resistance. It can be concluded that P 1134 is a very potent hypotensive agent with a haemodynamic profile identical to that seen with vasodilators with preferably act on precapillary resistance vessels. Potency and maximal efficacy exceeds that of hydralazine and seems like that of minoxidil. P 1134 is remarkably free from side-effects apart from causing water retention as all other vasodilators. It can be administered orally as well as intravenously. This makes P 1134 a very interesting compound in the treatment of moderate to severe hypertension, and further studies are well-founded.

Ultrafiltration and modified ultrafiltration in pediatric open heart operations.

PubMed

Elliott, M J

1993-12-01

The capillary leak associated with cardiopulmonary bypass results in an increase in content of water in the tissues measurable by an increase in total body water after cardiac operation. Following work by Magilligan in the 1970s, ultrafiltration was introduced during bypass as a means of hemoconcentrating patients and potentially removing water from the tissues. Conventional methods proved inconsistent; thus, we modified the technique to ultrafilter the patients immediately after cessation of bypass. Modified ultrafiltration takes 10 minutes and results in an elevation of the on-bypass hematocrit to about 35% or 40%. In pilot studies comparing bypass in absence of ultrafiltration with conventional ultrafiltration and modified ultrafiltration, only the modified technique was seen reliably to reduce the elevation in total body water to only 4%, within a narrow range. Subsequent prospective studies confirmed the reduction in accumulation of total body water and also demonstrated a reduction in blood loss and in requirements for blood transfusion. Systolic blood pressure was observed to increase uniformly in all patients undergoing modified ultrafiltration. This effect was investigated and found to be associated with a marked increase in cardiac index, no change in systemic vascular resistance, a decrease in heart rate, and a marked decrease in pulmonary vascular resistance. Recently, we have demonstrated an increase in contractility and a decrease in myocardial wall volume. The modified technique of ultrafiltration has been employed successfully in more than 400 patients in our institution, and represents an excellent option for perioperative management of both accumulation of fluid in the tissues and hemodynamics after hypothermic bypass.

Dosimetric comparison of three intensity-modulated radiation therapies for left breast cancer after breast-conserving surgery.

PubMed

Zhang, Huai-Wen; Hu, Bo; Xie, Chen; Wang, Yun-Lai

2018-05-01

This study aimed to evaluate dosimetric differences of intensity-modulated radiation therapy (IMRT) in target and normal tissues after breast-conserving surgery. IMRT five-field plan I, IMRT six-field plan II, and field-in-field-direct machine parameter optimization-IMRT plan III were designed for each of the 50 patients. One-way analysis of variance was performed to compare differences, and P < 0.05 was considered statistically significant. Homogeneity index of plan III is lower than those of plans I and II. No difference was identified in conformity index of targets. Plan I exhibited difference in mean dose (D mean ) for the heart (P < 0.05). Plan I featured smaller irradiation dose volumes in V 5 , V 20 (P < 0.05) of the left lung than II. Plan I exhibited significantly higher V 5 in the right lung than plans II and III (P < 0.05). Under plan I, irradiation dose at V 5 in the right breast is higher than that in plans II and III. Patients in plan III presented less total monitor unit and total treatment time than those in plans I and II (P < 0.05). IMRT six-field plans II, and field-in-field-direct machine parameter optimization-IMRT plans III can reduce doses and volumes to the lungs and heart better while maintaining satisfying conformity index and homogeneity index of target. Nevertheless, plan II neglects target movements caused by respiration. In the same manner, plan III can substantially reduce MU and shorten patient treatment time. Therefore, plan III, which considers target movement caused by respiration, is a more practical radiation mode. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Ultracompact, completely implantable permanent use electromechanical ventricular assist device and total artificial heart.

PubMed

Honda, N; Inamoto, T; Nogawa, M; Takatani, S

1999-03-01

An ultracompact, completely implantable permanent use electromechanical ventricular assist device (VAD) and total artificial heart (TAH) intended for 50-60 kg size patients have been developed. The TAH and VAD share a miniature electromechanical actuator that comprises a DC brushless motor and a planetary roller screw. The rotational force of the motor is converted into the rectilinear force of the roller screw to actuate the blood pump. The TAH is a one piece design with left and right pusher plate type blood pumps sandwiching an electromechanical actuator. The VAD is one half of the TAH with the same actuator but a different pump housing and a backplate. The blood contacting surfaces, including those of the flexing diaphragm and pump housing, of both the VAD and TAH were made of biocompatible polyurethane. The diameter, thickness, volume, and weight of the VAD are 90 mm, 56 mm, 285 cc, and 380 g, respectively, while those of the TAH are 90 mm, 73 mm, 400 cc, and 440 g, respectively. The design stroke volume of both the VAD and TAH is 60 cc with the stroke length being 12 mm. The stroke length and motor speed are controlled solely based on the commutation signals of the motor. An in vitro study revealed that a maximum pump flow of 7.5 L/min can be obtained with a pump rate of 140 bpm against a mean afterload of 100 mm Hg. The power requirement ranged from 4 to 6 W to deliver a 4-5 L/min flow against a 100 mm Hg afterload with the electrical-to-hydraulic efficiency being 19-20%. Our VAD and TAH are the smallest of the currently available devices and suitable for bridge to transplant application as well as for permanent circulatory support of 50-60 kg size patients.

[Effects of multidisciplinary blood management strategy on transfusion and outcomes in patients undergoing valvular heart surgery].

PubMed

Ji, Hongwen; Li, Zhiyuan; Sun, Hansong; Li, Lihuan; Long, Cun; Ma, Li; Chen, Lei; Wang, Wei; Hu, Shengshou

2014-02-25

To evaluate the effect of multidisciplinary blood management strategy in adults patients undergoing valvular heart surgery. A multidisciplinary patient blood management (PBM) strategy was instituted in Fuwai Hospital since January 2009. It includes Establishment of a multidisciplinary blood transfusion management team and designation of a coordinator; Enactment perioperative transfusion triggers (Hb < 80 g/L) for adults patients undergoing cardiac surgery; recommendation of antifibrinolytics, cell salvage, reduced cardiopulmonary bypass circuit; setting up Blood Consumption Announcement and Scoring System, which regularly publishes notifications of blood volume consumed per case, per single procedure and per surgeon. Clinical date before and after multidisciplinary patient blood management strategy will be presented. A total of 3 951 consecutive patients underwent Valvular Heart Surgery were analyzed. 1 713 cases were in pre-PBM group, and 2 238 cases were in post-PBM group. Both incidence and average units of allogeneic red blood cell transfusion perioperatively in post-PBM group were decreased (28.5% vs 75.3%, P = 0.000, and 1.2 U vs 4.0 U, P = 0.000). The postoperative length of stay in hospital and incidence of pneumonia were reduced in post-PBM group (8.2 d vs 10.5 d, P = 0.02, and 2.7% vs 3.5%, P = 0.04). The post-PBM group had lower in-hospital mortality (0.6% vs 1.2%, P = 0.000). Multidisciplinary patient blood management strategy significantly reduced blood transfusion, morbidity and mortality in patients underwent valvular heart surgery. It save plenty of blood resources.

Comparison of the cardiovascular effects of meptazinol and naloxone following haemorrhagic shock in rats and cats.

PubMed Central

Chance, E.; Paciorek, P. M.; Todd, M. H.; Waterfall, J. F.

1985-01-01

The cardiovascular effects of the opioid mixed agonist-antagonist, meptazinol, and the opioid antagonist, naloxone, have been evaluated in conscious rats, anaesthetized rats and anaesthetized cats following the induction of haemorrhagic shock. The mean arterial pressure of conscious rats decreased by 17-29 mmHg following a haemorrhage of 20% of blood volume. Meptazinol (17 mg kg-1, i.m.) administered after haemorrhage evoked a rapid and sustained increase in mean arterial pressure to pre-haemorrhage levels. Naloxone (10 mg kg-1, i.v.) also increased mean arterial pressure to a level significantly higher than post-haemorrhage values. Neither haemorrhage nor subsequent drug treatments evoked significant changes in the heart rates of conscious rats. In anaesthetized rats, 20% haemorrhage evoked decreases in mean arterial pressure, heart rate and cardiac output. Blood flow to the heart, skin, skeletal muscle, kidneys, spleen and liver (arterial) was decreased. Meptazinol and naloxone increased blood pressure and total peripheral resistance, but did not significantly alter heart rate or cardiac output. Hepatic arterial flow decreased further in both drug and vehicle treated groups. In addition meptazinol slightly reduced skeletal muscle flow. In anaesthetized cats 40% haemorrhage decreased mean arterial pressure by 46 +/- 3 mmHg. An intravenous infusion of either meptazinol or naloxone (cumulative 2 mg kg-1, i.v.) partially restored blood pressure. In experimental animal models of haemorrhagic shock, meptazinol has a similar cardiovascular profile to naloxone. The established analgesic activity of meptazinol may confer an advantage in some shock states. PMID:4052729

[Pharmacological and mechanical support of the myocardium in perioperative period in cardio-surgical patients with chronic heart failure].

PubMed

Babaev, M A; Eremenko, A A; Ziuliaeva, T P; Fedulova, S V; Molochnikov, I O; Fominykh, M V; Poliakova, P V; Dzemeshkevich, S L

2014-01-01

The article deals with a retrospective study devoted to the combined methods of myocardial support in cardiosurgical patients with chronic heart failure (III-IY FC according to NYHA) and low myocardial reserves capacity (LVEF 28.3 +/- 9.4%). This methods include pharmacologic (Levosimendan) and mechanical support (IABP). During the work we have analyzed data of 116 patients and measured pressure in the pulmonary artery (mmHg), end-systolic volume (ESV ml), end-diastolic volume (ED, ml), stroke volume output (SVO, ml), left ventricular ejection fraction (LVEF, %). We evaluated the level of valvular insufficiency and pulmonary hypertension (PH) and BNP concentration (pg/ml). The following indications for the usage of pharmacological and/or mechanical myocardial support were identified: I) Preventive usage of pharmacological and/or mechanical myocardial support is recommended for patients with CHF III-IY FC (NYHA) and low left ventricular EF(< or = 35%), significant valvular insufficiency, PH, PICS (postinfarction cardiosclerosis); 2) The certain method of the support can be chosen with the help of Levosimendan infusion testing; 3) In case one of the above mentioned indications (point 1) or in case of mild reaction to levosimendan infusion in patients with the lesions of more than 2 coronary arteries (including the trunk of the left coronary artery) the usage of combined support is recommended; 4) In case of < or = 6 scores according to EUROSCORE scale, lesions of 2 or more coronary arteries, tricuspid insufficiency (TriI), PH, and high pressure in pulmonary artery (higher than the 2nd degree), high end-diastolic volume, end-systolic volume of LV the isolated usage of levosimendan is recommended; 5) In case of significant ischemic heart disease, PICS, lesions of more than 2 coronary arteries, (including the trunk of the left coronary artery) but without significant decrease of pressure in the pulmonary artery, end-diastolic volume, end-systolic volume and TriI the isolated usage of IABP is recommended.

Pediatric heart allocation and transplantation in Eurotransplant.

PubMed

Smits, Jacqueline M; Thul, Josef; De Pauw, Michel; Delmo Walter, Eva; Strelniece, Agita; Green, Dave; de Vries, Erwin; Rahmel, Axel; Bauer, Juergen; Laufer, Guenther; Hetzer, Roland; Reichenspurner, Hermann; Meiser, Bruno

2014-09-01

Pediatric heart allocation in Eurotransplant (ET) has evolved over the past decades to better serve patients and improve utilization. Pediatric heart transplants (HT) account for 6% of the annual transplant volume in ET. Death rates on the pediatric heart transplant waiting list have decreased over the years, from 25% in 1997 to 18% in 2011. Within the first year after listing, 32% of all infants (<12 months), 20% of all children aged 1-10 years, and 15% of all children aged 11-15 years died without having received a heart transplant. Survival after transplantation improved over the years, and in almost a decade, the 1-year survival went from 83% to 89%, and the 3-year rates increased from 81% to 85%. Improved medical management of heart failure patients and the availability of mechanical support for children have significantly improved the prospects for children on the heart transplant waiting list. © 2014 Steunstichting ESOT.

Effect of antioxidant therapy with dl-alpha-tocopherol on cardiovascular structure in experimental renal failure.

PubMed

Amann, Kerstin; Törnig, Johannes; Buzello, Mareike; Kuhlmann, Alexander; Gross, Marie-Luise; Adamczak, Marcin; Buzello, Moriz; Ritz, Eberhard

2002-09-01

Chronic renal failure is characterized by remodeling of the structure of the heart and the vasculature, for example, left ventricular hypertrophy, myocardial fibrosis, capillary/myocyte mismatch, as well as thickening of intramyocardial arteries and of peripheral arteries and veins. Furthermore, uremia is a state of increased oxygen stress. It was the purpose of this study to examine whether these findings are interrelated. To investigate whether antioxidative therapy with dl-alpha-tocopherol (Toco; vitamin E) interferes with the development of abnormal cardiovascular structure in experimental renal failure, 28 male Sprague-Dawley rats were subjected to partial renal ablation (subtotal nephrectomy, SNX) or to sham operation (sham). SNX were either left untreated or received the antioxidant Toco (2 x 1500 IE/kg BW/week in the pellets). Blood pressure was measured using tail plethysmography. The experiment was terminated after 12 weeks. Heart and left ventricular weight were determined and the following parameters were measured using morphometry and stereology: volume densities of cardiomyocytes, capillaries and non-vascular interstitium; length density and total length of cardiac capillaries, wall thickness of intramyocardial arterioles and of the aorta. Systolic blood pressure and body weight were comparable in all groups. Treatment with Toco led to significantly increased plasma concentrations of Toco. Left ventricular weight and wall thickness of intramyocardial arteries were significantly higher in both SNX groups compared to sham controls. Volume density of the cardiac interstitial tissue was significantly higher in untreated SNX than in Toco treated SNX and sham control rats. Length density of capillaries was significantly lower in untreated SNX than in control rats; however, the values were significantly higher, and even higher than in sham controls, when SNX were treated with Toco. Treatment with the antioxidant dl-alpha-tocopherol prevented cardiomyocyte/capillary mismatch, and to some extent also myocardial fibrosis in rats with renal failure. The results point to a role of oxidative stress in the genesis of myocardial interstitial fibrosis and capillary deficit of the heart.

Footprint and imprint: an ecologic time-trend analysis of cardiovascular publications in general and specialty journals.

PubMed

Baldridge, Abigail S; Huffman, Mark D; Bloomfield, Gerald S; Prabhakaran, Dorairaj

2014-06-01

Studies have demonstrated strong associations between publication source and citations, as well as investigatory analysis of collaboration effects, in general and medical literature, but are limited to specific journals or short duration of time. This study sought to analyze time trends in cardiovascular research publications in leading general and specialty journals and to determine the association between collaboration and citation index. Cardiovascular publications were retrieved from Web of Knowledge by a cardiovascular bibliometric filter, and annual publication volumes in 8 general and specialty journals were compared. Univariable linear regression models were used to determine global and journal-specific trends for overall publication, cardiovascular publication, proportion of cardiovascular publication, collaboration, and citations. Cardiovascular publications increased (1999 to 2008) by 36% and number of sources by 74%. Volume increased in European Heart Journal (beta: 18.4, 95% confidence interval [CI]: 10.6 to 26.3) and decreased in Circulation (beta: -42.9, 95% CI: -79.3 to -6.5), Annals of Internal Medicine (beta: -1.9, 95% CI: -3.5 to -0.3), and Lancet (beta: -11.2, 95% CI: -14.7 to -7.8). Number of contributing countries increased in 3 journals: BMJ (beta: 0.8, 95% CI: 0.2 to 1.5), European Heart Journal (beta: -1.2, 95% CI: 0.8 to 1.7), and New England Journal of Medicine (beta: 1.6, 95% CI: 0.6 to 2.7). Fraction of collaborative publications increased (beta: 1.1 to 2.9) in all but Annals of Internal Medicine. Collaboration was associated with a higher median actual citation index (p < 0.0001). We found increasing trends in collaboration and citation in both general and specialty journals. Contribution by country in selected journals was disproportionate and under-represents total cardiovascular research in low- and middle-income countries. Copyright © 2014 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

Cardiac function is preserved following 4 weeks of voluntary wheel running in a rodent model of chronic kidney disease.

PubMed

Kuczmarski, James M; Martens, Christopher R; Kim, Jahyun; Lennon-Edwards, Shannon L; Edwards, David G

2014-09-01

The purpose of this investigation was to determine the effect of 4 wk of voluntary wheel running on cardiac performance in the 5/6 ablation-infarction (AI) rat model of chronic kidney disease (CKD). We hypothesized that voluntary wheel running would be effective in preserving cardiac function in AI. Male Sprague-Dawley rats were divided into three study groups: 1) sham, sedentary nondiseased control; 2) AI-SED, sedentary AI; and 3) AI-WR, wheel-running AI. Animals were maintained over a total period of 8 wk following AI and sham surgery. The 8-wk period included 4 wk of disease development followed by a 4-wk voluntary wheel-running intervention/sedentary control period. Cardiac performance was assessed using an isolated working heart preparation. Left ventricular (LV) tissue was used for biochemical tissue analysis. In addition, soleus muscle citrate synthase activity was measured. AI-WR rats performed a low volume of exercise, running an average of 13 ± 2 km, which resulted in citrate synthase activity not different from that in sham animals. Isolated AI-SED hearts demonstrated impaired cardiac performance at baseline and in response to preload/afterload manipulations. Conversely, cardiac function was preserved in AI-WR vs. sham hearts. LV nitrite + nitrate and expression of LV nitric oxide (NO) synthase isoforms 2 and 3 in AI-WR were not different from those of sham rats. In addition, LV H2O2 in AI-WR was similar to that of sham and associated with increased expression of LV superoxide-dismutase-2 and glutathione peroxidase-1/2. The findings of the current study suggest that a low-volume exercise intervention is sufficient to maintain cardiac performance in rats with CKD, potentially through a mechanism related to improved redox homeostasis and increased NO. Copyright © 2014 the American Physiological Society.

Percutaneous dilatational tracheostomy following total artificial heart implantation.

PubMed

Spiliopoulos, Sotirios; Dimitriou, Alexandros Merkourios; Serrano, Maria Rosario; Guersoy, Dilek; Autschbach, Ruediger; Goetzenich, Andreas; Koerfer, Reiner; Tenderich, Gero

2015-07-01

Coagulation disorders and an immune-altered state are common among total artificial heart patients. In this context, we sought to evaluate the safety of percutaneous dilatational tracheostomy in cases of prolonged need for mechanical ventilatory support. We retrospectively analysed the charts of 11 total artificial heart patients who received percutaneous dilatational tracheostomy. We focused on early and late complications. We observed no major complications and no procedure-related deaths. Early minor complications included venous oozing (45.4%) and one case of local infection. Late complications, including subglottic stenosis, stomal infection or infections of the lower respiratory tract, were not observed. In conclusion, percutaneous dilatational tracheostomy in total artificial heart patients is safe. Considering the well-known benefits of early tracheotomy over prolonged translaryngeal intubation, we advocate early timing of therapy in cases of prolonged mechanical ventilation. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Decay causes little loss in hickory

Treesearch

Frederick H. Berry; John A. Beaton

1972-01-01

A study of 600 hickory trees indicated that heart-rot fungi cause little economic loss in species of the genus Carya. More than half of the decay volume for which a fungus could be identified was caused by Poria spiculosa, one of seven species of heart-rot fungi associated with decay in hickory that were isolated and identified....

A comparison of methods to quantify the in-season training load of professional soccer players.

PubMed

Scott, Brendan R; Lockie, Robert G; Knight, Timothy J; Clark, Andrew C; Janse de Jonge, Xanne A K

2013-03-01

To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer. Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; <14.4 km/h], high-speed running [HSR; >14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product-moment correlations. Physical measures of TD, LSA volume, and player load provided large, significant (r = .71-.84; P < .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant (r = .40-.67; P < .01) correlations with measures of internal TL. While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.

Variation in critical care unit admission rates and outcomes for patients with acute coronary syndromes or heart failure among high- and low-volume cardiac hospitals.

PubMed

van Diepen, Sean; Bakal, Jeffrey A; Lin, Meng; Kaul, Padma; McAlister, Finlay A; Ezekowitz, Justin A

2015-02-27

Little is known about cross-hospital differences in critical care units admission rates and related resource utilization and outcomes among patients hospitalized with acute coronary syndromes (ACS) or heart failure (HF). Using a population-based sample of 16,078 patients admitted to a critical care unit with a primary diagnosis of ACS (n=14,610) or HF (n=1467) between April 1, 2003 and March 31, 2013 in Alberta, Canada, we stratified hospitals into high (>250), medium (200 to 250), or low (<200) volume based on their annual volume of all ACS and HF hospitalization. The percentage of hospitalized patients admitted to critical care units varied across low, medium, and high-volume hospitals for both ACS and HF as follows: 77.9%, 81.3%, and 76.3% (P<0.001), and 18.0%, 16.3%, and 13.0% (P<0.001), respectively. Compared to low-volume units, critical care patients with ACS and HF admitted to high-volume hospitals had shorter mean critical care stays (56.6 versus 95.6 hours, P<0.001), more critical care procedures (1.9 versus 1.2 per patient, <0.001), and higher resource-intensive weighting (2.8 versus 1.5, P<0.001). No differences in in-hospital mortality (5.5% versus 6.2%, adjusted odds ratio 0.93; 95% CI, 0.61 to 1.41) were observed between high- and low-volume hospitals; however, 30-day cardiovascular readmissions (4.6% versus 6.8%, odds ratio 0.77; 95% CI, 0.60 to 0.99) and cardiovascular emergency-room visits (6.6% versus 9.5%, odds ratio 0.80; 95% CI, 0.69 to 0.94) were lower in high-volume compared to low-volume hospitals. Outcomes stratified by ACS or HF admission diagnosis were similar. Cardiac patients hospitalized in low-volume hospitals were more frequently admitted to critical care units and had longer hospitals stays despite lower resource-intensive weighting. These findings may provide opportunities to standardize critical care utilization for ACS and HF patients across high- and low-volume hospitals. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Abnormal cardiovascular responses induced by localized high power microwave exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, S.-T; Brown, D.O.; Johnson, C.E.

1992-05-01

A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz and 16 Hz pulsemodulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in themore » neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power but not to the lower average power microwaves. Depression of pulse pressure, an indication of a decrease in stroke volume, and increased or decreased heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals.« less

Pre-shift fluid intake: effect on physiology, work and drinking during emergency wildfire fighting.

PubMed

Raines, Jenni; Snow, Rodney; Petersen, Aaron; Harvey, Jack; Nichols, David; Aisbett, Brad

2012-05-01

Wildfire fighters are known to report to work in a hypohydrated state, which may compromise their work performance and health. To evaluate whether ingesting a bolus of fluid before the shift had any effect on firefighters' fluid consumption, core temperature, or the time they spent in high heart rate and work activity zones when fighting emergency wildfires. Thirty-two firefighters were divided into non-bolus (AD) and pre-shift drinking bolus (PS, 500 ml water) groups. Firefighters began work hypohydrated as indicated by urine colour, specific gravity and plasma osmolality (P(osm)) results. Post-shift, firefighters were classified as euhydrated according to P(osm) and hypohydrated by urinary markers. No significant differences existed between the drinking groups in pre- or post-shift hydration status, total fluid intake, activity, heart rate or core temperature. Consuming a bolus of fluid, pre-shift provided no benefit over non-consumption as both groups had consumed equivalent ad libitum volumes of fluid, 2.5 h into the shift. No benefits of bolus consumption were observed in firefighter activity, heart rate response or core temperature response across the shift in the mild weather conditions experienced. Ad libitum drinking was adequate to facilitate rehydration in firefighters upon completion of their emergency firefighting work shift. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Pharmacokinetics and dromotropic activity of ajmaline in rats with hyperthyroidism.

PubMed Central

Hashimoto, Y.; Yasuhara, M.; Kamiya, A.; Okumura, K.; Hori, R.

1989-01-01

1. The pharmacokinetics and the dromotropic action (increased PQ interval) of intravenously administered ajmaline (2 mg kg-1) were studied in hyperthyroid rats with sinus tachycardia. The hyperthyroidism was induced by intraperitoneal injection of 3,5,3'-triiodo-L-thyronine (0.5 mg kg-1) for 4 days. 2. The change in the ajmaline concentration in whole blood could be described by a biexponential equation. The steady state distribution volume of ajmaline decreased from 4.81 l kg-1 in control rats to 3.80 l kg-1 in hyperthyroid rats and the total body blood clearance was slightly higher in hyperthyroid rats than in control rats. 3. Ajmaline exhibited a saturable binding to rat plasma proteins, and one kind of binding site was found in the observed range of concentrations. The binding capacity was 2 fold higher in hyperthyroid rats than in control rats. 4. On the basis of the plasma unbound concentration, ajmaline exhibited an increased negative dromotropic activity in hyperthyroid rats compared with control rats. 5. A positive correlation was found between the pacing rate and the dromotropic action of ajmaline on atrioventricular conduction in isolated perfused hearts. There was no significant difference in the rate-dependence of the effect of ajmaline on the heart between control and hyperthyroid rats. 6. Our findings suggest that the increased dromotropic activity of ajmaline is mainly due to the increased heart rate in hyperthyroid rats. PMID:2924068

Reduced baroreflex sensitivity with volume loading in conscious dogs

NASA Technical Reports Server (NTRS)

Vatner, S. F.; Boettcher, D. H.; Heyndrickx, G. R.; Mcritchie, R. J.

1975-01-01

Results of studies of the Bainbridge reflex in intact conscious dogs are presented. They indicate that arterial baroreflex sensitivity is reduced progressively as atrial pressure is raised by volume loading; this observation explains how heart rate can rise markedly in the presence of an elevated arterial blood pressure.

Demikhov's "Mechanical Heart": The Circumstances Surrounding Creation of the World's First Implantable Total Artificial Heart in 1937.

PubMed

Glyantsev, Sergey P; Tchantchaleishvili, Vakhtang; Bockeria, Leo A

2016-01-01

The world's first implantable total artificial heart was designed by Vladimir Demikhov as a fourth year biology student in Voronezh, Soviet Union, in 1937. As a prototype of his device, Demikhov must have used an apparatus for extracorporeal blood circulation invented by Sergei Bryukhonenko of Moscow. The device was the size of a dog's native heart and consisted of two diaphragm pumps brought into motion by an electric motor. A dog with an implanted device lived for 2.5 hours. In addition to having the prototype, the preconditions for Demikhov's artificial heart creation were his manual dexterity, expertise in animal physiology, and his mechanistic worldview.

Functional adaptations of the coronary microcirculation to anaemia in fetal sheep.

PubMed

Jonker, Sonnet S; Davis, Lowell; Soman, Divya; Belcik, J Todd; Davidson, Brian P; Atkinson, Tamara M; Wilburn, Adrienne; Louey, Samantha; Giraud, George D; Lindner, Jonathan R

2016-11-01

In fetuses, chronic anaemia stimulates cardiac growth; simultaneously, blood flow to the heart muscle itself is increased, and reserve blood flow capacity of the coronary vascular bed is preserved. Here we examined functional adaptations of the capillaries and small blood vessels responsible for delivering oxygen to the anaemic fetal heart muscle using contrast-enhanced echocardiography. We demonstrate that coronary microvascular flux rate doubled in anaemic fetuses compared to control fetuses, both at rest and during maximal flow, suggesting reduced microvascular resistance consistent with capillary widening. Cardiac fractional microvascular blood volume was not greater in anaemic fetuses, suggesting that growth of new microvascular vessels does not contribute to the increased flow per volume of myocardium. These unusual changes in microvascular function during anaemia may indicate novel adaptive strategies in the fetal heart. Fetal anaemia causes cardiac adaptations that have immediate and life-long repercussions on heart function and health. It is known that resting and maximal coronary conductance both increase during chronic fetal anaemia, but the coronary microvascular changes responsible for the adaptive response are unknown. Until recently, technical limitations have prevented quantifying functional capillary-level adaptations in the in vivo fetal heart. Our objective was to characterise functional microvascular adaptations in chronically anaemic fetal sheep. Chronically instrumented fetuses were randomized to a control group (n = 11) or were made anaemic by isovolumetric haemorrhage (n = 12) for 1 week prior to myocardial contrast echocardiography at 85% of gestation. Anaemia augmented cardiac mass by 23% without changing body weight. In anaemic fetuses, microvascular blood flow per volume of myocardium was twice that of control fetuses at rest, during vasodilatory hyperaemia, and during hyperaemia plus increased aortic pressure. The elevated blood flow was attributable almost entirely to an increase in microvascular blood flux rate whereas microvascular blood volumes were not different between groups at baseline, during hyperaemia, or with hyperaemia plus increased aortic pressure. Increased coronary microvascular flux rate in response to chronic fetal anaemia is consistent with expected reductions in capillary resistance from capillary diameter widening detected in earlier histological studies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Treatment of Heart Failure With Associated Functional Mitral Regurgitation Using the ARTO System: Initial Results of the First-in-Human MAVERIC Trial (Mitral Valve Repair Clinical Trial).

PubMed

Rogers, Jason H; Thomas, Martyn; Morice, Marie-Claude; Narbute, Inga; Zabunova, Milana; Hovasse, Thomas; Poupineau, Mathieu; Rudzitis, Ainars; Kamzola, Ginta; Zvaigzne, Ligita; Greene, Samantha; Erglis, Andrejs

2015-07-01

MAVERIC (Mitral Valve Repair Clinical Trial) reports the safety and efficacy of the ARTO system in patients with symptomatic heart failure and functional mitral regurgitation (FMR). The ARTO system percutaneously modifies the mitral annulus to improve leaflet coaptation in FMR. The MAVERIC trial is a prospective, nonrandomized first-in-human study. Key inclusion criteria were systolic heart failure New York Heart Association functional classes II to IV, FMR grade ≥2+, left ventricular (LV) ejection fraction ≤40%, LV end-diastolic diameter >50 mm and ≤75 mm. Exclusion criteria were clinical variables that precluded feasibility of the ARTO procedure. Primary outcomes were safety (30-day major adverse events) and efficacy (MR reduction, LV volumes, and functional status). Eleven patients received the ARTO system, and there were no procedural adverse events. From baseline to 30 days, there were meaningful improvements. Effective regurgitant orifice area decreased from 30.3 ± 11.1 mm(2) to 13.5 ± 7.1 mm(2) and regurgitant volumes from 45.4 ± 15.0 ml to 19.5 ± 10.2 ml. LV end-systolic volume index improved from 77.5 ± 24.3 ml/m(2) to 68.5 ± 21.4 ml/m(2), and LV end-diastolic volume index 118.7 ± 28.6 ml/m(2) to 103.9 ± 21.2 ml/m(2). Mitral annular anteroposterior diameter decreased from 45.0 ± 3.3 mm to 38.7 ± 3.0 mm. Functional status was 81.8% New York Heart Association functional class III/IV improving to 54.6% functional class I/II. At 30 days, there were 2 adverse events: 1 pericardial effusion requiring surgical drainage; and 1 asymptomatic device dislodgement. The ARTO system is a novel transcatheter device that can be used safely with meaningful efficacy in the treatment of FMR. (Mitral Valve Repair Clinical Trial [MAVERIC]; NCT02302872). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Applying the technique of volume-modulated arc radiotherapy to upper esophageal carcinoma.

PubMed

Ma, Pan; Wang, Xiaozhen; Xu, Yingjie; Dai, Jianrong; Wang, Luhua

2014-05-08

This study aims to evaluate the possibility of using the technique of volume-modulated arc therapy (VMAT) to combine the advantages of simplified intensity-modulated radiation therapy (sIMRT) with that of regular intensity-modulated radiation therapy (IMRT) in upper esophageal cancer. Ten patients with upper esophageal carcinoma were randomly chosen in this retrospective study. sIMRT, IMRT, and VMAT plans were generated to deliver 60 Gy in 30 fractions to the planning target volume (PTV). For each patient, with the same clinical requirements (target dose prescription, and dose/dose-volume constraints to organs at risk (OARs)), three plans were designed for sIMRT (five equispaced coplanar beams), IMRT (seven equispaced coplanar beams), and VMAT (two complete arcs). Comparisons were performed for dosimetric parameters of PTV and of OARs (lungs, spinal cord PRV, heart and normal tissue (NT)). All the plans were delivered to a phantom to evaluate the treatment time. The Wilcoxon matched-pairs, signed-rank test was used for intragroup comparison. For all patients, compared to sIMRT plans, VMAT plans statistically provide: a) significant improvement in HI and CI for PTV; b) significant decrease in delivery time, lung V20, MLD, heart V30 and spinal cord PRV D1cc; c) significant increase in NT V5; and d) no significant reduction in lung V5, V10, and heart MD. For all patients, compared to IMRT plans, VMAT plans statistically provide: a) significant improvement in CI for PTV; b) significant decrease in delivery time, lung V20, MLD, NT and spinal cord PRV D1cc; c) significant increase in NT V5; and d) no significant reduction in HI for PTV, lung V5, V10, heart V30 and heart MD. For patients with upper esophageal carcinoma, using VMAT significantly reduces the delivery time and the dose to the lungs compared with IMRT, and consequently saves as much treatment time as sIMRT. Considering those significant advantages, compared to sIMRT and IMRT, VMAT is the first choice of radiotherapy techniques for upper esophageal carcinoma.

The Blood Volume of the Guinea Pig: Effects of Epinephrine and Isoproterenol upon the Red Cell and Plasma Volumes, Heart Rate, and Mean Arterial Pressure,

DTIC Science & Technology

1987-09-01

capillaries (4), blood volumes calculated from plasma volume measures must correct for label that has left the system between the time of the injected dose...Splenic sequestration and contraction are mediated by the autonomic nervous system and blood-borne agents (10). Sympathetic nerve fibers from the truncus...sympathlcus and parasympathetic neurons of the nervus vagus (cranial nerve X) innervate the celiac plexus (8, 11). A subdivision of the celiac plexus

Comparison of PDR brachytherapy and external beam radiation therapy in the case of breast cancer

NASA Astrophysics Data System (ADS)

Teymournia, L.; Berger, D.; Kauer-Dorner, D.; Poljanc, K.; Seitz, W.; Aiginger, H.; Kirisits, C.

2009-04-01

Pulsed dose rate brachytherapy (PDR) was compared to external beam radiation therapy (EBRT) in the case of breast cancer. The benefits were figured out by evaluation of dosimetric parameters and calculating the normal tissue complication probability (NTCP). PDR plans were set up for five randomly chosen left-sided breast cancer patients delivering a total dose of 50.4 Gy to the target (dose rate 0.8 Gy h-1). For EBRT five left-sided breast cancer patients were planned using 3D-conformal tangential photon beams with a prescribed total dose of 50 Gy (2 Gy/fraction) to the total breast volume. For plan ranking and NTCP calculation the physical dose was first converted into the biologically effective dose (BED) and then into the normalized total dose (NTD) using the linear quadratic model with an α/β ratio of 3 Gy. In PDR the relative effectiveness (RE) was calculated for each dose bin of the differential dose volume histogram to get the BED. NTCPs were calculated for the ipsilateral lung and the heart as contoured on CT slices based on the Lyman model and the Kutcher reduction scheme. Dosimetric parameters as Vth (percentage of the total volume exceeding a threshold dose) and Jackson's fdam (fraction of the organ damaged) were also used to figure out the benefits. The comparison of calculated NTCPs in PDR and EBRT showed no difference between these two modalities. All values were below 0.01%. fdam derived from EBRT was always higher (mean value 8.95% versus 1.21% for the lung). The mean V10 and V20 of the lung related to BED were 6.32% and 1.72% for PDR versus 11.72% and 9.59% for EBRT. When using dosimetric parameters as Vth and fdam, PDR was mostly superior to EBRT in respect of sparing normal tissues. NTCP calculation as a single method of modality ranking showed a lack of information, especially when normal tissue was exposed to low radiation doses.

Cardioprotective Effects of Total Flavonoids Extracted from Xinjiang Sprig Rosa rugosa against Acute Ischemia/Reperfusion-Induced Myocardial Injury in Isolated Rat Heart.

PubMed

Hou, Xuejiao; Han, Jichun; Yuan, Changsheng; Ren, Huanhuan; Zhang, Ya; Zhang, Tao; Xu, Lixia; Zheng, Qiusheng; Chen, Wen

2016-01-01

This study evaluated the antioxidative and cardioprotective effects of total flavonoids extracted from Xinjiang sprig Rosa rugosa on ischemia/reperfusion (I/R) injury using an isolated Langendorff rat heart model. The possible mechanism of Xinjiang sprig rose total flavonoid (XSRTF) against I/R injury was also studied. XSRTF (5, 10, and 20 µg/mL) dissolved in Krebs-Henseleit buffer was administered to isolated rat heart. The XSRTF showed remarkable scavenging effects against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide anion radicals in vitro. XSRTF pretreatment improved the heart rate, increased LVDP, and decreased CK and LDH levels in coronary flow. This pretreatment also increased SOD activity and GSH/GSSG ratio but decreased MDA, TNF-α, and CRP levels and IL-8 and IL-6 activities. The infarct size and cell apoptosis in the hearts from the XSRTF-treated group were lower than those in the hearts from the I/R group. Therefore, the cardioprotective effects of XSRTF may be attributed to its antioxidant, antiapoptotic, and anti-inflammatory activities.

Physiological responses of mules on prolonged exposure to high altitude (3 650 m)

NASA Astrophysics Data System (ADS)

Riar, S. S.; Shankar Bhat, K.; Sen Gupta, J.

1982-06-01

Eight healthy male animals were inducted and kept for 2 1/2 years at 3 650 m altitude and subjected to normal work schedules. Physiological measurements viz. heart rate, blood pressure, minute ventilation, oxygen consumption, respiration rate, hemoglobin, packed cell haematocrit volume and eosinophil count were made on these animals at periodic intervals. On acute induction to an altitude of 3 650 m these animals demonstrated a sudden increase in tidal volume, a decrease in Rf and no change in VE, suggesting a decreased dead space/tidal volume ratio at altitude. However, all these changes stabilised within 3 weeks but on prolongation of stay, the physical state of these animals was adversely affected. The respiratory adjustments occurring on return to sea level appear to be a response to thermal stress. The initial increase in heart rate and blood pressure stabilised by the 2nd week.

Dynamic three-dimensional phase-contrast technique in MRI: application to complex flow analysis around the artificial heart valve

NASA Astrophysics Data System (ADS)

Kim, Soo Jeong; Lee, Dong Hyuk; Song, Inchang; Kim, Nam Gook; Park, Jae-Hyeung; Kim, JongHyo; Han, Man Chung; Min, Byong Goo

1998-07-01

Phase-contrast (PC) method of magnetic resonance imaging (MRI) has bee used for quantitative measurements of flow velocity and volume flow rate. It is a noninvasive technique which provides an accurate two-dimensional velocity image. Moreover, Phase Contrast Cine magnetic resonance imaging combines the flow dependent contrast of PC-MRI with the ability of cardiac cine imaging to produce images throughout the cardiac cycle. However, the accuracy of the data acquired from the single through-plane velocity encoding can be reduced by the effect of flow direction, because in many practical cases flow directions are not uniform throughout the whole region of interest. In this study, we present dynamic three-dimensional velocity vector mapping method using PC-MRI which can visualize the complex flow pattern through 3D volume rendered images displayed dynamically. The direction of velocity mapping can be selected along any three orthogonal axes. By vector summation, the three maps can be combined to form a velocity vector map that determines the velocity regardless of the flow direction. At the same time, Cine method is used to observe the dynamic change of flow. We performed a phantom study to evaluate the accuracy of the suggested PC-MRI in continuous and pulsatile flow measurement. Pulsatile flow wave form is generated by the ventricular assistant device (VAD), HEMO-PULSA (Biomedlab, Seoul, Korea). We varied flow velocity, pulsatile flow wave form, and pulsing rate. The PC-MRI-derived velocities were compared with Doppler-derived results. The velocities of the two measurements showed a significant linear correlation. Dynamic three-dimensional velocity vector mapping was carried out for two cases. First, we applied to the flow analysis around the artificial heart valve in a flat phantom. We could observe the flow pattern around the valve through the 3-dimensional cine image. Next, it is applied to the complex flow inside the polymer sac that is used as ventricle in totally implantable artificial heart (TAH). As a result we could observe the flow pattern around the valves of the sac, though complex flow can not be detected correctly in the conventional phase contrast method. In addition, we could calculate the cardiac output from TAH sac by quantitative measurement of the volume of flow across the outlet valve.

N-Terminal Pro-B-Type Natriuretic Peptide and Subclinical Brain Damage in the General Population.

PubMed

Zonneveld, Hazel I; Ikram, M Arfan; Hofman, Albert; Niessen, Wiro J; van der Lugt, Aad; Krestin, Gabriel P; Franco, Oscar H; Vernooij, Meike W

2017-04-01

Purpose To investigate the association between N-terminal pro-B-type natriuretic peptide (NT-proBNP), which is a marker of heart disease, and markers of subclinical brain damage on magnetic resonance (MR) images in community-dwelling middle-aged and elderly subjects without dementia and without a clinical diagnosis of heart disease. Materials and Methods This prospective population-based cohort study was approved by a medical ethics committee overseen by the national government, and all participants gave written informed consent. Serum levels of NT-proBNP were measured in 2397 participants without dementia or stroke (mean age, 56.6 years; age range, 45.7-87.3 years) and without clinical diagnosis of heart disease who were drawn from the population-based Rotterdam Study. All participants were examined with a 1.5-T MR imager. Multivariable linear and logistic regression analyses were used to investigate the association between NT-proBNP level and MR imaging markers of subclinical brain damage, including volumetric, focal, and microstructural markers. Results A higher NT-proBNP level was associated with smaller total brain volume (mean difference in z score per standard deviation increase in NT-proBNP level, -0.021; 95% confidence interval [CI]: -0.034, -0.007; P = .003) and was predominantly driven by gray matter volume (mean difference in z score per standard deviation increase in NT-proBNP level, -0.037; 95% CI: -0.057, -0.017; P < .001). Higher NT-proBNP level was associated with larger white matter lesion volume (mean difference in z score per standard deviation increase in NT-proBNP level, 0.090; 95% CI: 0.051, 0.129; P < .001), with lower fractional anisotropy (mean difference in z score per standard deviation increase in NT-proBNP level, -0.048; 95% CI: -0.088, -0.008; P = .019) and higher mean diffusivity (mean difference in z score per standard deviation increase in NT-proBNP level, 0.054; 95% CI: 0.018, 0.091; P = .004) of normal-appearing white matter. Conclusion In community-dwelling persons, higher serum NT-proBNP levels are associated with volumetric and microstructural MR imaging markers of subclinical brain damage. © RSNA, 2016 Online supplemental material is available for this article.

[Photoselective vaporization of the prostate in severe heart disease or dementia patients who are not candidates for TUR-P].

PubMed

Kuwahara, Yoshitaka; Otsuki, Hideo; Nagakubo, Ichiro; Horiba, Masaki

2008-09-01

TUR-P for the treatment of BPH is not performed in cases with severe heart disease due to the risk of bleeding and hyponatremia etc. Besides, in cases with severe central nerve disease and dementia, TUR-P is not performed because patients cannot take postoperative rest. We report the efficacy and the safety of Photoselective Vaporization of the Prostate (PVP) using a high-power 80 W KTP (potassiumu-titayl-phosphate) in patients for whom TUR-P cannot be performed. 312 patients underwent PVP in our hospital. Of these 312 patients, 8 patients with severe heart disease (American Society of Anesthesiology score of 3 or greater) and 4 patients with severe dementia (Performance status of 3 or greater) were evaluated. We assessed peak flow rate and post-void residual urine volume preoperatively and at 3 months postoperatively, safety of the procedure, and complication rates. The mean age was 81 years old (range 67 to 94) and the mean prostate volume was 63.8 ml (range 19 to 120). Urethral catheter was used in 8 patients because of chronic urinary retention. PVP was performed with GreenLightPV and a saline solution was used for irrigation. Upon completion of the procedure an 18Fr Foley catheter was inserted without continuous bladder irrigation and removed next morning, as a rule. In all 12 patients, PVP was performed successfully without any intraoperative complications. Mean operating time was 101 minutes (range 28 to 184), mean total laser energy was 336,853 J (range 74,396 to 550,000), and mean irrigation volume was 21 L (range 8 to 36). The hemoglobin value changed from mean 13.1 mg/dl preoperatively to 12.2 mg/dl postoperatively. Blood transfusions were not required and hyponatremia was not observed. In 1 case, the urethral catheter was removed 3 hours following surgery. In the other cases, the urethral catheter was removed next morning. All patients could urinate after catheter removal and were discharged on the day following operation. Mean peak flow rate increased to 18 ml/s and mean post-void residual urine decreased to 46.9 ml at 3 months. No postoperative complications (urinary retention, hematuria, urinary tract infection, etc.) were observed. PVP is safe and effective in high-risk patients who are not candidates for TUR-P.

A new simplified volume-loaded heterotopic rabbit heart transplant model with improved techniques and a standard operating procedure.

PubMed

Lu, Wei; Zheng, Jun; Pan, Xu-Dong; Li, Bing; Zhang, Jin-Wei; Wang, Long-Fei; Sun, Li-Zhong

2015-04-01

The classic non-working (NW) heterotopic heart transplant (HTX) model in rodents had been widely used for researches related to immunology, graft rejection, evaluation of immunosuppressive therapies and organ preservation. But unloaded models are considered not suitable for some researches. Accordingly, We have constructed a volume-loaded (VL) model by a new and simple technique. Thirty male New Zealand White rabbits were randomly divided into two groups, group NW with 14 rabbits and group VL with 16 rabbits, which served as donors and recipients. We created a large and nonrestrictive shunt to provide left heart a sufficient preload. The donor superior vena cave and ascending aorta (AO) were anastomosed to the recipient abdominal aorta (AAO) and inferior vena cava (IVC), respectively. No animals suffered from paralysis, pneumonia and lethal bleeding. Recipients' mortality and morbidity were 6.7% (1/15) and 13.3% (2/15), respectively. The cold ischemia time in group VL is slight longer than that in group NW. The maximal aortic velocity (MAV) of donor heart was approximately equivalent to half that of native heart in group VL. Moreover, the similar result was achieved in the parameter of late diastolic mitral inflow velocity between donor heart and native heart in group VL. The echocardiography (ECHO) showed a bidirectional flow in donor SVC of VL model, inflow during diastole and outflow during systole. PET-CT imaging showed the standard uptake value (SUV) of allograft was equal to that of native heart in both groups on the postoperative day 3. We have developed a new VL model in rabbits, which imitates a native heart hemodynamically while only requiring a minor additional procedure. Surgical technique is simple compared with currently used HTX models. We also developed a standard operating procedure that significantly improved graft and recipient survival rate. This study may be useful for investigations in transplantation in which a working model is required.

Cardiovascular models of simulated moon and mars gravities: head-up tilt vs. lower body unweighting.

PubMed

Kostas, Vladimir I; Stenger, Michael B; Knapp, Charles F; Shapiro, Robert; Wang, Siqi; Diedrich, André; Evans, Joyce M

2014-04-01

In this study we compare two models [head-up tilt (HUT) vs. body unweighting using lower body positive pressure (LBPP)] to simulate Moon, Mars, and Earth gravities. A literature search did not reveal any comparisons of this type performed previously. We hypothesized that segmental fluid volume shifts (thorax, abdomen, upper and lower leg), cardiac output, and blood pressure (BP), heart rate (HR), and total peripheral resistance to standing would be similar in the LBPP and HUT models. There were 21 subjects who were studied while supine (simulation of spaceflight) and standing at 100% (Earth), 40% (Mars), and 20% (Moon) bodyweight produced by LBPP in Alter-G and while supine and tilted at 80 degrees, 20 degrees, and 10 degrees HUT (analogues of Earth, Mars, and Moon gravities, respectively). Compared to supine, fluid shifts from the chest to the abdomen, increases in HR, and decreases in stroke volume were greater at 100% bodyweight than at reduced weights in response to both LBPP and HUT. Differences between the two models were found for systolic BP, diastolic BP, mean arterial BP, stroke volume, total peripheral resistance, and thorax and abdomen impedances, while HR, cardiac output, and upper and lower leg impedances were similar. Bodyweight unloading via both LBPP and HUT resulted in cardiovascular changes similar to those anticipated in actual reduced gravity environments. The LBPP model/Alter-G has the advantage of providing an environment that allows dynamic activity at reduced bodyweight; however, the significant increase in blood pressures in the Alter-GC may favor the HUT model.

Postexercise hypotension in an endurance-trained population of men and women following high-intensity interval and steady-state cycling.

PubMed

Rossow, Lindy; Yan, Huimin; Fahs, Christopher A; Ranadive, Sushant M; Agiovlasitis, Stamatis; Wilund, Kenneth R; Baynard, Tracy; Fernhall, Bo

2010-04-01

The acute effect of high-intensity interval exercise (HI) on blood pressure (BP) is unknown although this type of exercise has similar or greater cardiovascular benefits compared to steady-state aerobic exercise (SS). This study examined postexercise hypotension (PEH) and potential mechanisms of this response in endurance-trained subjects following acute SS and HI. Sex differences were also evaluated. A total of 25 endurance-trained men (n = 15) and women (n = 10) performed a bout of HI and a bout of SS cycling in randomized order on separate days. Before exercise, 30 min postexercise, and 60 min postexercise, we measured brachial and aortic BP. Cardiac output (CO), stroke volume (SV), end diastolic volume (EDV), end systolic volume (ESV), and left ventricular wall-velocities were measured using ultrasonography with tissue Doppler capabilities. Ejection fraction and fractional shortening (FS), total peripheral resistance (TPR), and calf vascular resistance were calculated from the above variables and measures of leg blood flow. BP, ejection fraction, and FS decreased by a similar magnitude following both bouts but changes in CO, heart rate (HR), TPR, and calf vascular resistance were greater in magnitude following HI than following SS. Men and women responded similarly to HI. Although men and women exhibited a similar PEH following SS, they showed differential changes in SV, EDV, and TPR. HI acutely reduces BP similarly to SS. The mechanistic response to HI appears to differ from that of SS, and endurance-trained men and women may exhibit differential mechanisms for PEH following SS but not HI.

Survival in pediatric lung transplantation: The effect of center volume and expertise.

PubMed

Khan, Muhammad S; Zhang, Wei; Taylor, Rachel A; Dean McKenzie, E; Mallory, George B; Schecter, Marc G; Morales, David L S; Heinle, Jeffrey S; Adachi, Iki

2015-08-01

Institutional operative volume has been shown to impact outcomes of various procedures including lung transplantation (LTx). We sought to determine whether this holds true with pediatric LTx by comparing outcomes of adult centers (with larger overall volume) to those of pediatric centers (with smaller volume but more pediatric-specific experience). A retrospective analysis of the Organ Procurement and Transplant Network data was performed. Centers were categorized as either adult (LTx volume predominantly in adult patients), high-volume pediatric (HVP, ≥4 LTxs/year), or low-volume pediatric (LVP, <4 LTxs/year). Outcomes were compared in "younger children" (<12 years) and "older children and adolescents" (12 to 17 years). In total, 1,046 pediatric LTxs were performed between 1987 and 2012 at 62 centers (adult 51 [82%], HVP 3 [5%], LVP 8 [13%]). Although adult centers had larger overall LTx volume, their pediatric experiences were severely limited (median 1/year). In younger children, HVP centers were significantly better than LVP centers for patient survival (half-life: 7.3 vs 2.9 years, p = 0.002). Similarly, in older children and adolescents, HVP centers were significantly better than adult centers for patient survival (half-life: 4.6 vs 2.5 years, p = 0.001). Of note, even LVP centers tended to have longer patient survival than adult centers (p = 0.064). Multivariable analysis identified adult centers as an independent risk factor for graft failure (hazard ratio: 1.5, p < 0.001) as with LVP (hazard ratio: 1.3, p = 0.0078). Despite larger overall clinical volume, outcomes among pediatric LTx recipients in adult centers are not superior to those of pediatric centers. Not only center volume but pediatric-specific experience has an impact on outcomes in pediatric LTx. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Increased risk of volume overload with plasma compared with four‐factor prothrombin complex concentrate for urgent vitamin K antagonist reversal

PubMed Central

Refaai, Majed A.; Goldstein, Joshua N.; Lee, Martin L.; Durn, Billie L.; Milling, Truman J.; Sarode, Ravi

2015-01-01

BACKGROUND Plasma is commonly used for vitamin K antagonist (VKA) reversal, but observational studies suggest that it is associated with transfusion‐related adverse reactions (e.g., volume overload). However, this issue has not previously been addressed in a randomized controlled trial (RCT). STUDY DESIGN AND METHODS Factors associated with volume overload were examined using data from two Phase IIIb RCTs comparing plasma with four‐factor prothrombin complex concentrate (4F‐PCC, Beriplex/Kcentra, CSL Behring) for urgent VKA reversal. VKA‐treated patients with major bleeding (NCT00708435) or requiring an urgent surgical or invasive procedure (NCT00803101) were randomly assigned (1:1) to receive either plasma or 4F‐PCC, concomitant with vitamin K. Adverse events (AEs) and serious AEs were prospectively captured up to Day 10 and 45, respectively. Volume overload predictors were evaluated on a univariate and multivariate basis. RESULTS A total of 388 patients (4F‐PCC, n = 191; plasma, n = 197) were enrolled. Volume overload occurred in 34 (9%) patients (4F‐PCC, n = 9; plasma, n = 25). In univariate analyses, use of plasma (vs. 4F‐PCC), use of nonstudy plasma and/or platelets, race, history of congestive heart failure (CHF), and history of renal disease were associated with volume overload. In multivariate analyses, use of plasma (vs. 4F‐PCC), history of CHF, and history of renal disease were independent volume overload predictors. In an additional analysis restricted to volume overload events recorded up to Day 7, only use of plasma (vs. 4F‐PCC) was an independent volume overload predictor. CONCLUSIONS After adjusting for other potential risk factors, plasma use was independently associated with a greater risk of volume overload than 4F‐PCC in patients requiring urgent VKA reversal. PMID:26135740

Beat by beat stroke volume assessment by PDE in upright and supine exercise

NASA Technical Reports Server (NTRS)

1980-01-01

A 3.0 MHz pulse Doppler echocardiograph was used to estimate instantaneous stroke volume and cardiac output in 8 men during steady state supine and upright exercise at 300 kpm/min which were compared with other studies utilizing invasive procedures. The mean transients in heart rate and stroke volume and cardiac output for the first 20 sec of exercise in each posture were then determined. Centerline blood velocities were obtained in the ascending aorta with the transducer positioned manually in the suprasternal notch. Mean supine values for stroke volume and cardiac output at rest and exercise were 111 (6.4) and 112 ml (9.7 L/min), respectively, for supine. The corresponding results for upright were 76 (5.6) and 92 ml (8.4 L/min). These values compare favorably with prior studies. The transient response of cardiac output following the onset of upright was about twice as fast as in S because of the rapid and almost immediate upsurge in stroke volume. In supine, only heart rate served to augment cardiac output as stroke volume initially fell. The faster initial aortic flow in upright must represent the rapid mobilization of pooled venous blood from the leg veins which more than accounts for the additional volume (184 ml) of blood passing through the aorta during upright compared with supine in the first 20 sec.

Past and Present of Total Artificial Heart Therapy: A Success Story.

PubMed

Samak, Mostafa; Fatullayev, Javid; Sabashnikov, Anton; Zeriouh, Mohamed; Rahmanian, Parwis B; Choi, Yeong-Hoon; Wippermann, Jens; Wahlers, Thorsten; Schmack, Bastian; Ruhparwar, Arjang; Dohmen, Pascal M; Karck, Matthias; Popov, Aron-Frederik; Simon, André R; Weymann, Alexander

2015-09-07

The totally artificial heart (TAH) is among the most prominent medical innovations of the 21st century, especially due to the increasing population with end-stage heart failure. The progressive course of the disease, its resistance to conventional therapy, and the scarcity of hearts available for transplantation were the prime impetus for developing a TAH, especially when other options of mechanical circulatory assist devices are exhausted. In this review, we narrate the history of TAH, give an overview of its technology, and address the pros and cons of the currently available TAH models in light of published clinical experience.

Relationship Between Central and Peripheral Atherosclerosis and Left Ventricular Dysfunction in a Community Population

PubMed Central

Tsao, Connie W.; Gona, Philimon; Salton, Carol; Murabito, Joanne M.; Oyama, Noriko; Danias, Peter G.; O’Donnell, Christopher J.; Manning, Warren J.; Yeon, Susan B.

2011-01-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and PAD in a community cohort. 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65±9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional LV systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at Examination 7. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p<0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p<0.001) and volume of aortic plaque were associated with decreased ABI (p<0.001). After multivariable adjustment, ABI≤0.9 or prior revascularization was associated with a three-fold odds of aortic plaque (p=0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p<0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment suggesting shared mechanisms beyond those captured by traditional risk factors. PMID:21708875

The total artificial heart

PubMed Central

Cook, Jason A.; Shah, Keyur B.; Quader, Mohammed A.; Cooke, Richard H.; Kasirajan, Vigneshwar; Rao, Kris K.; Smallfield, Melissa C.; Tchoukina, Inna

2015-01-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient’s native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review. PMID:26793338

Mitral regurgitation: anatomy is destiny.

PubMed

Athanasuleas, Constantine L; Stanley, Alfred W H; Buckberg, Gerald D

2018-04-26

Mitral regurgitation (MR) occurs when any of the valve and ventricular mitral apparatus components are disturbed. As MR progresses, left ventricular remodelling occurs, ultimately causing heart failure when the enlarging left ventricle (LV) loses its conical shape and becomes globular. Heart failure and lethal ventricular arrhythmias may develop if the left ventricular end-systolic volume index exceeds 55 ml/m2. These adverse changes persist despite satisfactory correction of the annular component of MR. Our goal was to describe this process and summarize evolving interventions that reduce the volume of the left ventricle and rebuild its elliptical shape. This 'valve/ventricle' approach addresses the spherical ventricular culprit and offsets the limits of treating MR by correcting only its annular component.

Scaling dependence and synchronization of forced mercury beating heart systems

NASA Astrophysics Data System (ADS)

Biswas, Animesh; Das, Dibyendu; Parmananda, P.

2017-04-01

We perform experiments on a nonautonomous Mercury beating heart system, which is forced to pulsate using an external square wave potential. At suitable frequencies and volumes, the drop exhibits pulsation with polygonal shapes having n corners. We find the scaling dependence of the forcing frequency νn on the volume V of the drop and establish the relationship νn∝n/√{V } . It is shown that the geometrical shape of substrate is important for obtaining closer match to these scaling relationships. Furthermore, we study synchronization of two nonidentical drops driven by the same frequency and establish that synchrony happens when the relationship n2/n1=√{V2/V1 } is satisfied.

A Heart of Wisdom: Life Writing as Empathetic Inquiry. Complicated Conversation: A Book Series of Curriculum Studies. Volume 39

ERIC Educational Resources Information Center

Chambers, Cynthia M., Ed.; Hasebe-Ludt, Erika, Ed.; Leggo, Carl, Ed.; Sinner, Anita, Ed.

2012-01-01

This anthology explores life writing as a mode of educational inquiry, one where students and teachers may get a "heart of wisdom" as they struggle with the tensions and complexities of learning and teaching in challenging contemporary circumstances. Contributors write first-person creative non-fiction in a variety of life-writing…

Cardiopulmonary physiology: why the heart and lungs are inextricably linked.

PubMed

Verhoeff, Kevin; Mitchell, Jamie R

2017-09-01

Because the heart and lungs are confined within the thoracic cavity, understanding their interactions is integral for studying each system. Such interactions include changes in external constraint to the heart, blood volume redistribution (venous return), direct ventricular interaction (DVI), and left ventricular (LV) afterload. During mechanical ventilation, these interactions can be amplified and result in reduced cardiac output. For example, increased intrathoracic pressure associated with mechanical ventilation can increase external constraint and limit ventricular diastolic filling and, therefore, output. Similarly, high intrathoracic pressures can alter blood volume distribution and limit diastolic filling of both ventricles while concomitantly increasing pulmonary vascular resistance, leading to increased DVI, which may further limit LV filling. While LV afterload is generally considered to decrease with increased intrathoracic pressure, the question arises if the reduced LV afterload is primarily a consequence of a reduced LV preload. A thorough understanding of the interaction between the heart and lungs can be complicated but is essential for clinicians and health science students alike. In this teaching review, we have attempted to highlight the present understanding of certain salient aspects of cardiopulmonary physiology and pathophysiology, as well as provide a resource for multidisciplined health science educators and students. Copyright © 2017 the American Physiological Society.

Stroke volume obtained from the brachial artery using transbrachial electrical bioimpedance velocimetry.

PubMed

Henry, Isaac C; Bernstein, Donald P; Banet, Matt J

2012-01-01

Stroke volume (SV) is the quantity of blood ejected by the cardiac ventricles per each contraction. When SV is multiplied by heart rate, cardiac output is the result. Cardiac output (CO), in conjunction with hemoglobin concentration and arterial oxygen saturation are the cornerstones of oxygen transport. Measurement of CO is important, especially in sick humans suffering from decompensated heart disease and systemic diseases affecting the contractility or loading conditions of the heart. Although reasonably accurate invasive cardiac output methods are available, their use is restricted to those individuals hospitalized in the intensive care units. Thus, a robust noninvasive alternative is considered desirable. Impedance cardiography (ICG) is one such method, but in patients with severe heart disease and/or excess extravascular lung water, the method is inaccurate. This paper concerns the introduction of a new method, transbrachial electrical bioimpedance velocimetry (TBEV). The technique involves passage of a constant magnitude, high frequency, and low amperage ac from the upper arm to the antecubital fossa. In all other respects, the operational aspects of TBEV are consistent with ICG. There is good evidence suggesting that the TBEV waveform and its derivatives are generated by blood resistivity changes only.

Total anomalous pulmonary venous return

MedlinePlus

... the heart do not attach normally to the left atrium (left upper chamber of the heart). Instead, they attach ... returns through the pulmonary (lung) veins to the left side of the heart, which sends blood out ...

Heart position in snakes: response to "phylogeny, ecology, and heart position in snakes".

PubMed

Lillywhite, Harvey B; Seymour, Roger S

2011-01-01

Here we comment on a recent article (Gartner et al. 2010 ) that addresses previous adaptive interpretations of heart position in the context of gravity effects on blood circulation of snakes. The authors used phylogenetically based statistical methods and concluded that both habitat and phylogeny influence heart position, which they contend is relatively more posterior in arboreal compared to terrestrial species. Their result is based on measurements of heart position relative to snout-vent length, rather than total body length as in previous studies. However, gravity acts on the total length of the arterial-venous vasculature, and caudal segments of continuous blood columns cannot be ignored. Arboreal snakes have relatively long tails; therefore anterior hearts appear to be more "posterior" when the position is described relative to a shorter trunk. There is no physiologically valid explanation for the alleged posterior heart position in arboreal snakes, and multiple lines of published evidence to the contrary are ignored. The authors secondarily evaluated their data set with estimates for total body length based on measurements from other taxa. They found no statistical difference between heart position in arboreal versus terrestrial species, yet their article implied otherwise. Gartner et al. ( 2010 ) contrasted "aquatic" and terrestrial species throughout their paper, and they claimed there is no correlation between heart position and habitat among "aquatic and terrestrial species." But they did not include any aquatic species in their data set. Therefore, the article confuses rather than promotes understanding of cardiovascular adaptation to gravity.

SU-E-P-51: Dosimetric Comparison to Organs at Risk Sparing Using Volumetric-Modulated Arc Therapy Versus Intensity-Modulated Radiotherapy in Postoperative Radiotherapy of Left-Sided Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiao, L; Deng, G; Xie, J

2015-06-15

Purpose: To compare the dosimetric characteristics of volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for left-sided breast cancer patients with modified radical mastectomy. Methods: Twenty-four left-sided breast cancer patients treated with modified radical mastectomy were selected in this study. The planning target volume (PTV) was generated by using 7-mm uniform expansion of the clinical target volume (CTV) in all direction except the skin surface. The organs at risk (OARs) included heart, left lung, right lung, and right breast. Dose volume histograms (DVHs) were utilized to evaluate the dose distribution in PTV and OARs. Results: Bothmore » VMAT and IMRT plans met the requirement of PTV coverage. VMAT was superior to IMRT in terms of conformity, with a statistically significant difference (p=0.024). Mean doses, V5 and V10 of heart and both lungs in VMAT plans were significantly decreased compared to IMRT plans (P<0.05), but in terms of heart volume irradiated by high doses (V30 and V45), no significant differences were observed (P>0.05). For right breast, VMAT showed the reduction of V5 in comparison with IMRT (P<0.05). Additionally, the mean number of monitor units (MU) and treatment time in VMAT (357.21, 3.62 min) were significantly less than those in IMRT (1132.85, 8.74 min). Conclusion: VMAT showed similar PTV coverage and significant advantage in OARs sparing compared with IMRT, especially in terms of decreased volumes irradiated by low doses, while significantly reducing the treatment time and MU number.« less

Medication regimen complexity in ambulatory older adults with heart failure.

PubMed

Cobretti, Michael R; Page, Robert L; Linnebur, Sunny A; Deininger, Kimberly M; Ambardekar, Amrut V; Lindenfeld, JoAnn; Aquilante, Christina L

2017-01-01

Heart failure prevalence is increasing in older adults, and polypharmacy is a major problem in this population. We compared medication regimen complexity using the validated patient-level Medication Regimen Complexity Index (pMRCI) tool in "young-old" (60-74 years) versus "old-old" (75-89 years) patients with heart failure. We also compared pMRCI between patients with ischemic cardiomyopathy (ISCM) versus nonischemic cardiomyopathy (NISCM). Medication lists were retrospectively abstracted from the electronic medical records of ambulatory patients aged 60-89 years with heart failure. Medications were categorized into three types - heart failure prescription medications, other prescription medications, and over-the-counter (OTC) medications - and scored using the pMRCI tool. The study evaluated 145 patients (n=80 young-old, n=65 old-old, n=85 ISCM, n=60 NISCM, mean age 73±7 years, 64% men, 81% Caucasian). Mean total pMRCI scores (32.1±14.4, range 3-84) and total medication counts (13.3±4.8, range 2-30) were high for the entire cohort, of which 72% of patients were taking eleven or more total medications. Total and subtype pMRCI scores and medication counts did not differ significantly between the young-old and old-old groups, with the exception of OTC medication pMRCI score (6.2±4 young-old versus 7.8±5.8 old-old, P =0.04). With regard to heart failure etiology, total pMRCI scores and medication counts were significantly higher in patients with ISCM versus NISCM (pMRCI score 34.5±15.2 versus 28.8±12.7, P =0.009; medication count 14.1±4.9 versus 12.2±4.5, P =0.008), which was largely driven by other prescription medications. Medication regimen complexity is high in older adults with heart failure, and differs based on heart failure etiology. Additional work is needed to address polypharmacy and to determine if medication regimen complexity influences adherence and clinical outcomes in this population.

Magnetic resonance imaging during untreated ventricular fibrillation reveals prompt right ventricular overdistention without left ventricular volume loss.

PubMed

Berg, Robert A; Sorrell, Vincent L; Kern, Karl B; Hilwig, Ronald W; Altbach, Maria I; Hayes, Melinda M; Bates, Kathryn A; Ewy, Gordon A

2005-03-08

Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms. Ventricular dimensions were determined by MRI for 30 minutes of untreated VF in a closed-chest, closed-pericardium model in 6 swine. Within 1 minute of untreated VF, mean right ventricular volume increased by 29% but did not increase thereafter. During the first 5 minutes of untreated VF, mean left ventricular volume increased by 34%. Between 20 and 30 minutes of VF, stone heart occurred as manifested by dramatic thickening of the myocardium and concomitant substantial decreases in left ventricular volume. In this closed-chest swine model of VF, substantial right ventricular volume changes occurred early and did not result in smaller left ventricular volumes. The changes in ventricular volumes before the late development of stone heart do not explain why defibrillation from brief duration VF (<5 minutes) typically results in a pulsatile rhythm with return of spontaneous circulation, whereas defibrillation from prolonged VF (5 to 15 minutes) does not.

National practice patterns for management of adult congenital heart disease: operation by pediatric heart surgeons decreases in-hospital death.

PubMed

Karamlou, Tara; Diggs, Brian S; Person, Thomas; Ungerleider, Ross M; Welke, Karl F

2008-12-02

Surgery for grown-up (age > or = 18 years) patients with congenital heart disease (GUCH) is frequently performed by surgeons without specialization in pediatric heart surgery. We sought to define national practice patterns and to determine whether outcomes for GUCH patients are improved if they are treated by specialized pediatric heart surgeons (PHSs) compared with non-PHSs. We identified index cardiac procedures in patients with 12 congenital heart disease diagnostic groups using the Nationwide Inpatient Sample 1988 to 2003. PHSs were defined as surgeons whose annual practice volumes were made of >75% annual pediatric heart cases. GUCH operations were defined as operations within these 12 diagnoses occurring in patients > or =18 years of age. We identified 30,250 operations, yielding a national estimate of 152,277 +/- 7,875 operations. Of these, 111,816 +/- 7,456 (73%) were pediatric operations, and 40,461 +/- 1,365 (27%) were GUCH operations. PHSs performed 68% of pediatric operations in all diagnostic groups, whereas non-PHSs performed 95% of GUCH operations within the same diagnostic groups (P<0.0001). In-hospital death rates for GUCH patients operated on by PHSs were lower than death rates for GUCH patients operated on by non-PHSs (1.87% [95% CI, 0.62 to 3.13] versus 4.84% [95% CI, 4.30 to 5.38%]; P<0.0001). Survival advantage increased with increasing surgeon annual pediatric volume (P=0.0031). Pediatric patients within specific diagnostic groups are more likely to undergo operation by PHSs, whereas GUCH patients within the same diagnostic groups are more likely to undergo operation by non-PHSs. In-hospital death rates are lower for GUCH patients operated on by PHSs. GUCH patients should be encouraged to obtain surgical operation by PHS.

Modelling the interaction among several mechanisms in the short-term arterial pressure control.

PubMed

Ursino, M

2000-01-01

A Mathematical model of the short-term arterial pressure control in humans is presented. It includes a six-compartment description of the vascular system, an elastance variable model of the pulsating heart, two groups of baroreceptors (high-pressure or sinoaortic baroreceptors and low-pressure or cardiopulmonary baroreceptors), the efferent activity in the sympathetic nerves and in the vagus, and the response of four distinct effectors (heart period, systemic peripheral resistance, systemic venous unstressed volume and heart contractility). Several experimental results reported in the physiological literature can be reproduced with the model quite well. The examples presented in this work include the effect of combined sympathetic and vagal stimulation on heart rate, the baroreflex response to mild and severe acute haemorrhages, and the baroreflex response to ventricular pacing at different rates performed during atrioventricular block. The results suggest that: i) The sympathetic nerves and the vagus interact linearly in regulating heart period. The apparent negative interaction observed experimentally can be ascribed merely to the hyperbolic relationship which links heart rate to heart period. ii) The cardiopulmonary baroafferents play a significant role in the control of systemic arterial pressure during mild haemorrhages (lower than 3-4% of the overall blood volume). In this range, they may allow arterial pressure to be maintained at its normal level without the intervention of the sinoaortic baroreceptors. In contrast, the sinoaortic baroreceptors become the major responsible of the observed cardiovascular adjustments during more severe haemorrhages, when the role of cardiopulmonary baroreceptors becomes progressively exhausted. iii) The stability margin of the closed-loop system is quite low. Increasing the static gain of the baroreceptors or reducing the rate-dependent component may result in self-sustained oscillations similar to Mayer waves.

Effect of Different Formulations of Magnesium Chloride Used As Anesthetic Agents on the Performance of the Isolated Heart of Octopus vulgaris.

PubMed

Pugliese, Chiara; Mazza, Rosa; Andrews, Paul L R; Cerra, Maria C; Fiorito, Graziano; Gattuso, Alfonsina

2016-01-01

Magnesium chloride (MgCl 2 ) is commonly used as a general anesthetic in cephalopods, but its physiological effects including those at cardiac level are not well-characterized. We used an in vitro isolated perfused systemic heart preparation from the common octopus, Octopus vulgaris , to investigate: (a) if in vivo exposure to MgCl 2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery and (b) direct effects of MgCl 2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl 2 in sea water (20 min) or to a mixture of MgCl 2 + ethanol (1.12/1%; 20 min) showed cardiac function (heart rate, stroke volume, cardiac output) comparable to hearts removed from animals killed under hypothermia. However, 3.5% MgCl 2 (1:1, sea water: distilled water, 20 min) produced a significant impairment of the Frank-Starling response as did 45 min exposure to the MgCl 2 + ethanol mixture. Perfusion of the isolated heart with MgCl 2 ± ethanol formulations produced a concentration-related bradycardia (and arrest), a decreased stroke volume and cardiac output indicating a direct effect on the heart. The cardiac effects of MgCl 2 are discussed in relation to the involvement of magnesium, sodium, chloride, and calcium ions, exposure time and osmolality of the formulations and the implications for the use of various formulations of MgCl 2 as anesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl 2 in sea water or to a mixture of MgCl 2 + ethanol is limited to ~20 min, residual effects on cardiac function are unlikely to impact post-anesthetic recovery.

Influence of different treatment techniques on radiation dose to the LAD coronary artery

PubMed Central

Nieder, Carsten; Schill, Sabine; Kneschaurek, Peter; Molls, Michael

2007-01-01

Background The purpose of this proof-of-principle study was to test the ability of an intensity-modulated radiotherapy (IMRT) technique to reduce the radiation dose to the heart plus the left ventricle and a coronary artery. Radiation-induced heart disease might be a serious complication in long-term cancer survivors. Methods Planning CT scans from 6 female patients were available. They were part of a previous study of mediastinal IMRT for target volumes used in lymphoma treatment that included 8 patients and represent all cases where the left anterior descending coronary artery (LAD) could be contoured. We compared 6 MV AP/PA opposed fields to a 3D conformal 4-field technique and an optimised 7-field step-and-shoot IMRT technique and evaluated DVH's for several structures. The planning system was BrainSCAN 5.21 (BrainLAB, Heimstetten, Germany). Results IMRT maintained target volume coverage but resulted in better dose reduction to the heart, left ventricle and LAD than the other techniques. Selective dose reduction could be accomplished, although not to the degree initially attempted. The median LAD dose was approximately 50% lower with IMRT. In 5 out of 6 patients, IMRT was the best technique with regard to heart sparing. Conclusion IMRT techniques are able to reduce the radiation dose to the heart. In addition to dose reduction to whole heart, individualised dose distributions can be created, which spare, e.g., one ventricle plus one of the coronary arteries. Certain patients with well-defined vessel pathology might profit from an approach of general heart sparing with further selective dose reduction, accounting for the individual aspects of pre-existing damage. PMID:17547777

Characteristics of patients with severe heart failure exhibiting exercise oscillatory ventilation.

PubMed

Matsuki, Ryosuke; Kisaka, Tomohiko; Ozono, Ryoji; Kinoshita, Hiroki; Sada, Yoshiharu; Oda, Noboru; Hidaka, Takayuki; Tashiro, Naonori; Takahashi, Makoto; Sekikawa, Kiyokazu; Ito, Yoshihiro; Kimura, Hiroaki; Hamada, Hironobu; Kihara, Yasuki

2013-01-01

This study aims to elucidate the characteristics of patients with severe nonischemic heart failure exhibiting exercise oscillatory ventilation (EOV) and the association of these characteristics with the subjective dyspnea. Forty-six patients with nonischemic heart failure who were classified into the New York Heart Association (NYHA) functional class III underwent cardiopulmonary exercise testing (CPX) and were divided into two groups according to the presence or absence of EOV. We evaluated the patients by using the Specific Activity Scale (SAS), biochemical examination, echocardiographic evaluation, results of CPX and symptoms during CPX (Borg scale), and reasons for exercise termination. EOV was observed in 20 of 46 patients. The following characteristics were observed in patients with EOV as compared with those without EOV with statistically significant differences: more patients complaining dyspnea as the reason for exercise termination, lower SAS score, higher N-terminal pro-brain natriuretic peptide level, larger left atrial dimension and volume, left ventricular end-diastolic volume, higher Borg scale score at rest and at the anerobic threshold, higher respiratory rate at rest and at peak exercise, and higher slope of the minute ventilation-to-CO₂ output ratio, and lower end-tidal CO₂ pressure at peak exercise. Among the subjects with NYHA III nonischemic heart failure, more patients with EOV had a stronger feeling of dyspnea during exercise as compared with those without EOV, and the subjective dyspnea was an exercise-limiting factor in many cases.

A dual-input nonlinear system analysis of autonomic modulation of heart rate

NASA Technical Reports Server (NTRS)

Chon, K. H.; Mullen, T. J.; Cohen, R. J.

1996-01-01

Linear analyses of fluctuations in heart rate and other hemodynamic variables have been used to elucidate cardiovascular regulatory mechanisms. The role of nonlinear contributions to fluctuations in hemodynamic variables has not been fully explored. This paper presents a nonlinear system analysis of the effect of fluctuations in instantaneous lung volume (ILV) and arterial blood pressure (ABP) on heart rate (HR) fluctuations. To successfully employ a nonlinear analysis based on the Laguerre expansion technique (LET), we introduce an efficient procedure for broadening the spectral content of the ILV and ABP inputs to the model by adding white noise. Results from computer simulations demonstrate the effectiveness of broadening the spectral band of input signals to obtain consistent and stable kernel estimates with the use of the LET. Without broadening the band of the ILV and ABP inputs, the LET did not provide stable kernel estimates. Moreover, we extend the LET to the case of multiple inputs in order to accommodate the analysis of the combined effect of ILV and ABP effect on heart rate. Analyzes of data based on the second-order Volterra-Wiener model reveal an important contribution of the second-order kernels to the description of the effect of lung volume and arterial blood pressure on heart rate. Furthermore, physiological effects of the autonomic blocking agents propranolol and atropine on changes in the first- and second-order kernels are also discussed.

Increased pulmonary transit times in asymptomatic dogs with mitral regurgitation.

PubMed

Lord, Peter; Eriksson, Anders; Häggström, Jens; Järvinen, Anna-Kaisa; Kvart, Clarence; Hansson, Kerstin; Maripuu, Enn; Mäkelä, Olli

2003-01-01

Pulmonary transit time (PTT) normalized to heart rate (nPTT) is a measure of the pulmonary blood volume (PBV) to stroke volume ratio (PBV/SV). It is an index of cardiac performance. To determine the effect of compensated mitral regurgitation (CMR) and decompensated mitral regurgitation (DMR) caused by valvular endocardiosis on the index nPTT, we measured nPTT by first-pass radionuclide angiocardiography and ECG in 13 normal dogs, 18 dogs with CMR, and 13 dogs with DMR. PTT was measured as time between onset of appearance of activity at the pulmonary trunk and the left atrium. In the normal dogs, the relationship between PTT and mean R-R interval (mRR) was PTT = 4.08 x mRR + 0.15 (R2 = 0.71). Normal nPTT was 4.4 +/- 0.6 (SD) (range. 3.6-5.3). in CMR, 6.3 +/- 1.6 (SD) (range, 4.0-9.7). and in DMR, 11.9 +/- 3.4 (SD) (range, 8.0-18.8). The differences among all groups were significant. Heart rates were 110 +/- 22 bpm in normal dogs, 111 +/- 20 in dogs with CMR, and 144 +/- 18 in dogs with DMR (P < .001 for difference between DMR group and normal and CMR groups). Increased nPTT in CMR indicates preclinical heart pump dysfunction. Heart rate-normalized pulmonary transit times may be a useful index of heart function in mitral regurgitation.

Serial optical coherence scanning reveals an association between cardiac function and the heart architecture in the aging rodent heart

PubMed Central

Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Avti, Pramod; Moeini, Mohammad; Lesage, Frédéric

2017-01-01

Normal aging is accompanied by structural changes in the heart architecture. To explore this remodeling, we used a serial optical coherence tomography scanner to image entire mouse hearts at micron scale resolution. Ex vivo hearts of 7 young (4 months) and 5 old (24 months) C57BL/6 mice were acquired with the imaging platform. OCT of the myocardium revealed myofiber orientation changing linearly from the endocardium to the epicardium. In old mice, this rate of change was lower when compared to young mice while the average volume of old mice hearts was significantly larger (p<0.05). Myocardial wall thickening was also accompanied by extracellular spacing in the endocardium, resulting in a lower OCT attenuation coefficient in old mice endocardium (p<0.05). Prior to serial sectioning, cardiac function of the same hearts was imaged in vivo using MRI and revealed a reduced ejection fraction with aging. The use of a serial optical coherence tomography scanner allows new insight into fine age-related changes of the heart associated with changes in heart function. PMID:29188099

Problem Behavior and Heart Rate Reactivity in Adopted Adolescents: Longitudinal and Concurrent Relations

ERIC Educational Resources Information Center

Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.

2008-01-01

The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…

[Effect of the sharply strengthened motor activity on heart pumping ability of rats and mechanisms of its regulation].

PubMed

Nikitin, A S; Abzalov, R A; Abzalov, N I; Vafina, E Z

2013-08-01

The indicators of heart pumping ability of rats at a muscular loading of the maximum power and also in the conditions of transition from sharply strengthened motor activity regime on a strengthened motor activity regime at adrenergic influence stimulation and blockade were investigated. At rats of 100-daily age at the strengthened motor activity heart rate is less, and blood stroke volume is more, than in the rats, subject to muscular loading of the maximum power. The adrenergic influence on the heart's pumping ability of sharply strengthened motor activity rats is much more, than of unlimited motor activity rats. At the α1-adrenoreceptors blockade at 100-daily rats the decreasing in intensity of muscular loading causes increased in adrenergic influence on heart pumping ability.

Monte Carlo calculated doses to treatment volumes and organs at risk for permanent implant lung brachytherapy

NASA Astrophysics Data System (ADS)

Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

2013-10-01

Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used with sublobar resection to treat stage I non-small cell lung cancer and other radionuclides, 169Yb and 103Pd, are considered for these treatments. This work investigates the dosimetry of permanent implant lung brachytherapy for a range of source energies and various implant sites in the lung. Monte Carlo calculated doses are calculated in a patient CT-derived computational phantom using the EGsnrc user-code BrachyDose. Calculations are performed for 103Pd, 125I, 131Cs seeds and 50 and 100 keV point sources for 17 implant positions. Doses to treatment volumes, ipsilateral lung, aorta, and heart are determined and compared to those determined using the TG-43 approach. Considerable variation with source energy and differences between model-based and TG-43 doses are found for both treatment volumes and organs. Doses to the heart and aorta generally increase with increasing source energy. TG-43 underestimates the dose to the heart and aorta for all implants except those nearest to these organs where the dose is overestimated. Results suggest that model-based dose calculations are crucial for selecting prescription doses, comparing clinical endpoints, and studying radiobiological effects for permanent implant lung brachytherapy.

A computer model of the pediatric circulatory system for testing pediatric assist devices.

PubMed

Giridharan, Guruprasad A; Koenig, Steven C; Mitchell, Michael; Gartner, Mark; Pantalos, George M

2007-01-01

Lumped parameter computer models of the pediatric circulatory systems for 1- and 4-year-olds were developed to predict hemodynamic responses to mechanical circulatory support devices. Model parameters, including resistance, compliance and volume, were adjusted to match hemodynamic pressure and flow waveforms, pressure-volume loops, percent systole, and heart rate of pediatric patients (n = 6) with normal ventricles. Left ventricular failure was modeled by adjusting the time-varying compliance curve of the left heart to produce aortic pressures and cardiac outputs consistent with those observed clinically. Models of pediatric continuous flow (CF) and pulsatile flow (PF) ventricular assist devices (VAD) and intraaortic balloon pump (IABP) were developed and integrated into the heart failure pediatric circulatory system models. Computer simulations were conducted to predict acute hemodynamic responses to PF and CF VAD operating at 50%, 75% and 100% support and 2.5 and 5 ml IABP operating at 1:1 and 1:2 support modes. The computer model of the pediatric circulation matched the human pediatric hemodynamic waveform morphology to within 90% and cardiac function parameters with 95% accuracy. The computer model predicted PF VAD and IABP restore aortic pressure pulsatility and variation in end-systolic and end-diastolic volume, but diminish with increasing CF VAD support.

Automated segmentation of cardiac visceral fat in low-dose non-contrast chest CT images

NASA Astrophysics Data System (ADS)

Xie, Yiting; Liang, Mingzhu; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

2015-03-01

Cardiac visceral fat was segmented from low-dose non-contrast chest CT images using a fully automated method. Cardiac visceral fat is defined as the fatty tissues surrounding the heart region, enclosed by the lungs and posterior to the sternum. It is measured by constraining the heart region with an Anatomy Label Map that contains robust segmentations of the lungs and other major organs and estimating the fatty tissue within this region. The algorithm was evaluated on 124 low-dose and 223 standard-dose non-contrast chest CT scans from two public datasets. Based on visual inspection, 343 cases had good cardiac visceral fat segmentation. For quantitative evaluation, manual markings of cardiac visceral fat regions were made in 3 image slices for 45 low-dose scans and the Dice similarity coefficient (DSC) was computed. The automated algorithm achieved an average DSC of 0.93. Cardiac visceral fat volume (CVFV), heart region volume (HRV) and their ratio were computed for each case. The correlation between cardiac visceral fat measurement and coronary artery and aortic calcification was also evaluated. Results indicated the automated algorithm for measuring cardiac visceral fat volume may be an alternative method to the traditional manual assessment of thoracic region fat content in the assessment of cardiovascular disease risk.

Influence of Dai-kenchu-to (DKT) on human portal blood flow.

PubMed

Ogasawara, Takashi; Morine, Yuji; Ikemoto, Tetsuya; Imura, Satoru; Fujii, Masahiko; Soejima, Yuji; Shimada, Mitsuo

2008-01-01

Dai-kenchu-to (DKT) is known as an herbal medicine used for postoperative ileus. However, no report exists about the effect of DKT on portal blood flow. The aim of this study is to clarify the influence of DKT on portal blood flow. To healthy volunteers (Healthy; n = 6), cirrhotic patients (Cirrhosis; n = 7) and liver-transplant patients (LTx; n = 3), DKT (2.5g) with 100mL of warm water was orally administrated in the DKT group, and only warm water was administrated in the control group. The portal blood flow rate (M-VEL: cm/sec.) and portal blood flow (Flow volume: mL/min.) was measured each time after administration using an ultrasonic Doppler method. Furthermore, the arterial blood pressure and heart rate was measured at the same time points. In the DKT group, a significant increase of M-VEL (120%) and flow volume (150%) 30 minutes after administration was observed in both Healthy and Cirrhosis in comparison with the control group. In LTx, there was also a significant increase of flow volume (128%) 30 minutes after administration. However, there was no change in average blood pressure and heart rate in all groups. DKT increases portal blood flow in early phase after oral administration without any significant changes in the blood pressure and heart rate.

Modification of a Volume-Overload Heart Failure Model to Track Myocardial Remodeling and Device-Related Reverse Remodeling

PubMed Central

Tuzun, Egemen; Bick, Roger; Kadipasaoglu, Cihan; Conger, Jeffrey L.; Poindexter, Brian J.; Gregoric, Igor D.; Frazier, O. H.; Towbin, Jeffrey A.; Radovancevic, Branislav

2011-01-01

Purpose. To provide an ovine model of ventricular remodeling and reverse remodeling by creating congestive heart failure (CHF) and then treating it by implanting a left ventricular assist device (LVAD). Methods. We induced volume-overload heart failure in 2 sheep; 20 weeks later, we implanted an LVAD and assessed recovery 11 weeks thereafter. We examined changes in histologic and hemodynamic data and levels of cellular markers of CHF. Results. After CHF induction, we found increases in LV end-diastolic pressure, LV systolic and diastolic dimensions, wall thickness, left atrial diameter, and atrial natriuretic protein (ANP) and endothelin-1 (ET-1) levels; β-adrenergic receptor (BAR) and dystrophin expression decreased markedly. Biopsies confirmed LV remodeling. After LVAD support, LV systolic and diastolic dimensions, wall thickness, and mass, and ANP and ET-1 levels decreased. Histopathologic and hemodynamic markers improved, and BAR and dystrophin expression normalized. Conclusions. We describe a successful sheep model for ventricular and reverse remodeling. PMID:22347659

Extracellular matrix directions estimation of the heart on micro-focus x-ray CT volumes

NASA Astrophysics Data System (ADS)

Oda, Hirohisa; Oda, Masahiro; Kitasaka, Takayuki; Akita, Toshiaki; Mori, Kensaku

2017-03-01

In this paper we propose an estimation method of extracellular matrix directions of the heart. Myofiber are surrounded by the myocardial cell sheets whose directions have strong correspondence between heart failure. Estimation of the myocardial cell sheet directions is difficult since they are very thin. Therefore, we estimate the extracellular matrices which are touching to the sheets as if piled up. First, we perform a segmentation of the extracellular matrices by using the Hessian analysis. Each extracellular matrix region has sheet-like shape. We estimate the direction of each extracellular matrix region by the principal component analysis (PCA). In our experiments, mean inclination angles of two normal canine hearts were 50.6 and 46.2 degrees, while the angle of a failing canine heart was 57.4 degrees. This results well fit the anatomical knowledge that failing hearts tend to have vertical myocardical cell sheets.

'Athlete's heart' in prepubertal children.

PubMed

Rowland, T W; Delaney, B C; Siconolfi, S F

1987-05-01

Bradycardia, cardiomegaly, heart murmurs, and ECG changes are typically observed in adult endurance athletes, but frequency of such changes among children involved in sports training is unclear. Pediatricians need to be aware of whether these features of the "athlete's heart" occur in their patients, because such features may mimic those of cardiac disease. Fourteen prepubertal competitive male swimmers were evaluated by physical examination, ECG and echocardiogram, and findings were compared to those of a group of active but nontrained control boys. Lower resting heart rates and echocardiographic manifestations of chronic left ventricular volume overload were observed among the swimmers. These changes were not manifest on physical examination, however, and no significant ECG alterations were identified among the athletes. These findings indicate that, although features of the athlete's heart are present in children involved in endurance training, seldom will these findings simulate heart disease or be apparent on routine clinical examination.

Bursting into space: alterations of sympathetic control by space travel

NASA Technical Reports Server (NTRS)

Eckberg, D. L.

2003-01-01

AIM: Astronauts return to Earth with reduced red cell masses and hypovolaemia. Not surprisingly, when they stand, their heart rates may speed inordinately, their blood pressures may fall, and some may experience frank syncope. We studied autonomic function in six male astronauts (average +/- SEM age: 40 +/- 2 years) before, during, and after the 16-day Neurolab space shuttle mission. METHOD: We recorded electrocardiograms, finger photoplethysmographic arterial pressures, respiration, peroneal nerve muscle sympathetic activity, plasma noradrenaline and noradrenaline kinetics, and cardiac output, and we calculated stroke volume and total peripheral resistance. We perturbed autonomic function before and during spaceflight with graded Valsalva manoeuvres and lower body suction, and before and after the mission with passive upright tilt. RESULTS: In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33%) in three subjects, in whom noradrenaline spillover and clearance also were increased. Valsalva straining provoked greater reductions of arterial pressure, and proportionally greater sympathetic responses in space than on Earth. Lower body suction elicited greater increases of sympathetic nerve activity, plasma noradrenaline, and noradrenaline spillover in space than on Earth. After the Neurolab mission, left ventricular stroke volume was lower and heart rate was higher during tilt, than before spaceflight. No astronaut experienced orthostatic hypotension or pre-syncope during 10 min of post-flight tilting. CONCLUSION: We conclude that baseline sympathetic outflow, however measured, is higher in space than on earth, and that augmented sympathetic nerve responses to Valsalva straining, lower body suction, and post-flight upright tilt represent normal adjustments to greater haemodynamic stresses associated with hypovolaemia.

Cerebral blood velocity and other cardiovascular responses to 2 days of head-down tilt

NASA Technical Reports Server (NTRS)

Frey, Mary A. B.; Mader, Thomas H.; Bagian, James P.; Charles, John B.; Meehan, Richard T.

1993-01-01

Spaceflight induces a cephalad redistribution of fluid volume and blood flow within the human body, and space motion sickness, which is a problem during the first few days of space flight, could be related to these changes in fluid status and in blood flow of the cerebrum and vestibular system. To evaluate possible changes in cerebral blood flow during simulated weightlessness, we measured blood velocity in the middle cerebral artery (MCA) along with retinal vascular diameters, intraocular pressure, impedance cardiography, and sphygmomanometry on nine men (26.2 +/- 6.6 yr) morning and evening for 2 days during continuous 10 deg head-down tilt (HDT). When subjects went from seated to head-down bed rest, their heart rate and retinal diameters decreased, and intraocular pressures increased. After 48 h of HDT, blood flow velocity in the MCA was decreased and thoracic impedance was increased, indicating less fluid in the thorax. Percent changes in blood flow velocities in the MCA after 48 h of HDT were inversely correlated with percent changes in retinal vascular diameters. Blood flow velocities in the MCA were inversely correlated (intersubject) with arterial pressures and retinal vascular diameters. Heart rate, stroke volume, cardiac output, systolic arterial pressure, and at times pulse pressure and blood flow velocities in the MCA were greater in the evening. Total peripheral resistance was higher in the morning. Although cerebral blood velocity is reduced after subjects are head down for 2 days, the inverse relationship with retinal vessel diameters, which have control analogous to that of cerebral vessels, indicates cerebral blood flow is not reduced.