Effect of hypokinesia on cardiac contractile function and nervous regulation of the heart

NASA Technical Reports Server (NTRS)

Meyerson, F. Z.; Kapelko, V. I.; Gorina, M. S.; Shchegolkov, A. N.; Larinov, N. P.

1980-01-01

Longterm hypokinesia caused cardiac deadaptation in rabbits, which resulted in the diminishing of the left ventricular rate of contraction and relaxation, joined later by decreased vascular resistance. As a results, the ejection rate as well as stroke volume and cardiac output were normal. The decrease of the relaxation speed was more obvious at a high heart rate and results in shortening of the diastolic pause and diminishing of cardiac output. Hearts of the hypokinetic animals were characterized by normal maximal pressure developed by a unit of muccardial mass aorta clamping, decreased adrenoreactivity, and increased cholinoreactivity. This complex of changes is contrary to changes observed in adaptation to exercise, but is similar to changes observed in compensatory hypertrophy of the heart.

Blood Volume Response to Physical Activity and Inactivity

DTIC Science & Technology

2007-07-01

feedback to promote volume excretion and maintain blood volume at its normal baseline level. Physical activity does not alter either arterial pressure or...although this is less clear. The increase in total blood volume then increases the ability to maintain a high stroke volume and a lower heart rate for...compelling evidence that reduced blood vol- ume with age may be a result of a sedentary, high caloric lifestyle rather than the aging process. There

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.

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.

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.

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

[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.

Body mass and cardiovascular reactivity to racism in African American college students.

PubMed

Clark, Vernessa R; Hill, Oliver W

2009-01-01

The purpose of the present study was to examine the effects of body mass on cardiovascular reactivity to racism in African American college students. Cardiac output, stroke volume, heart rate and blood pressure were measured as participants viewed a racially noxious scene on videotape. Body mass was measured using body mass index calculated using height and weight. We hypothesized that obese individuals would have greater cardiovascular reactivity to the scene than overweight individuals or individuals with normal weight. We also hypothesized that obese women would have the greatest cardiovascular reactivity to the scenes compared to overweight and normal weight women, and obese, overweight, and normal weight men. Lastly, we hypothesized that women would have greater cardiovascular reactivity than their male counterparts. Multivariate analysis of variance revealed that obese participants had significantly greater stroke volume and cardiac output than participants of normal weight, indicating that obese participants were less emotionally aroused by the stressor. There was also a significant interaction between sex and body mass for heart rate reactivity between the stressor and recovery periods. Obese women had the largest drop in heart rate, while obese men had the smallest drop from the stressor period to the recovery period. The findings revealed that obese participants were less aroused by the stressors and recovered from them more quickly than overweight participants and participants of normal weight. The frequent experiences of weight prejudices by the obese group may have desensitized them to other prejudices such as the racial intolerance shown in the stressor.

Striking volume intolerance is induced by mimicking arterial baroreflex failure in normal left ventricular function.

PubMed

Funakoshi, Kouta; Hosokawa, Kazuya; Kishi, Takuya; Ide, Tomomi; Sunagawa, Kenji

2014-01-01

Patients with heart failure and preserved ejection fraction (HFpEF) are supersensitive to volume overload, and a striking increase in left atrial pressure (LAP) often occurs transiently and is rapidly resolved by intravascular volume reduction. The arterial baroreflex is a powerful regulator of intravascular stressed blood volume. We examined whether arterial baroreflex failure (FAIL) mimicked by constant carotid sinus pressure (CSP) causes a striking increase in LAP and systemic arterial pressure (AP) by volume loading in rats with normal left ventricular (LV) function. In anesthetized Sprague-Dawley rats, we isolated bilateral carotid sinuses and controlled CSP by a servo-controlled piston pump. We mimicked the normal arterial baroreflex by matching CSP to instantaneous AP and FAIL by maintaining CSP at a constant value regardless of AP. We infused dextran stepwise (infused volume [Vi]) until LAP reached 15 mm Hg and obtained the LAP-Vi relationship. We estimated the critical Vi as the Vi at which LAP reached 20 mm Hg. In FAIL, critical Vi decreased markedly from 19.4 ± 1.6 mL/kg to 15.6 ± 1.6 mL/kg (P < .01), whereas AP at the critical Vi increased (194 ± 6 mm Hg vs 163 ± 6 mm Hg; P < .01). We demonstrated that an artificial arterial baroreflex system we recently developed could fully restore the physiologic volume intolerance in the absence of native arterial baroreflex. Arterial baroreflex failure induces striking volume intolerance in the absence of LV dysfunction and may play an important role in the pathogenesis of acute heart failure, especially in states of HFpEF. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Exact mode volume and Purcell factor of open optical systems

NASA Astrophysics Data System (ADS)

Muljarov, E. A.; Langbein, W.

2016-12-01

The Purcell factor quantifies the change of the radiative decay of a dipole in an electromagnetic environment relative to free space. Designing this factor is at the heart of photonics technology, striving to develop ever smaller or less lossy optical resonators. The Purcell factor can be expressed using the electromagnetic eigenmodes of the resonators, introducing the notion of a mode volume for each mode. This approach allows an analytic treatment, reducing the Purcell factor and other observables to sums over eigenmode resonances. Calculating the mode volumes requires a correct normalization of the modes. We introduce an exact normalization of modes, not relying on perfectly matched layers. We present an analytic theory of the Purcell effect based on this exact mode normalization and the resulting effective mode volume. We use a homogeneous dielectric sphere in vacuum, which is analytically solvable, to exemplify these findings. We furthermore verify the applicability of the normalization to numerically determined modes of a finite dielectric cylinder.

Relationship between linear and nonlinear dynamics of heart rate and impairment of lung function in COPD patients.

PubMed

Mazzuco, Adriana; Medeiros, Wladimir Musetti; Sperling, Milena Pelosi Rizk; de Souza, Aline Soares; Alencar, Maria Clara Noman; Arbex, Flávio Ferlin; Neder, José Alberto; Arena, Ross; Borghi-Silva, Audrey

2015-01-01

In chronic obstructive pulmonary disease (COPD), functional and structural impairment of lung function can negatively impact heart rate variability (HRV); however, it is unknown if static lung volumes and lung diffusion capacity negatively impacts HRV responses. We investigated whether impairment of static lung volumes and lung diffusion capacity could be related to HRV indices in patients with moderate to severe COPD. Sixteen sedentary males with COPD were enrolled in this study. Resting blood gases, static lung volumes, and lung diffusion capacity for carbon monoxide (DLCO) were measured. The RR interval (RRi) was registered in the supine, standing, and seated positions (10 minutes each) and during 4 minutes of a respiratory sinus arrhythmia maneuver (M-RSA). Delta changes (Δsupine-standing and Δsupine-M-RSA) of the standard deviation of normal RRi, low frequency (LF, normalized units [nu]) and high frequency (HF [nu]), SD1, SD2, alpha1, alpha2, and approximate entropy (ApEn) indices were calculated. HF, LF, SD1, SD2, and alpha1 deltas significantly correlated with forced expiratory volume in 1 second, DLCO, airway resistance, residual volume, inspiratory capacity/total lung capacity ratio, and residual volume/total lung capacity ratio. Significant and moderate associations were also observed between LF/HF ratio versus total gas volume (%), r=0.53; LF/HF ratio versus residual volume, %, r=0.52; and HF versus total gas volume (%), r=-0.53 (P<0.05). Linear regression analysis revealed that ΔRRi supine-M-RSA was independently related to DLCO (r=-0.77, r (2)=0.43, P<0.05). Responses of HRV indices were more prominent during M-RSA in moderate to severe COPD. Moreover, greater lung function impairment was related to poorer heart rate dynamics. Finally, impaired lung diffusion capacity was related to an altered parasympathetic response in these patients.

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

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.

The Cardiovascular Effects of Obesity on Ventricular Function and Mass in Patients after Tetralogy of Fallot Repair.

PubMed

Fogel, Mark A; Pawlowski, Thomas; Keller, Marc S; Cohen, Meryl S; Goldmuntz, Elizabeth; Diaz, Laura; Li, Christine; Whitehead, Kevin K; Harris, Matthew A

2015-08-01

To determine the cardiovascular effects of obesity on patients with tetralogy of Fallot (TOF) repair. Ventricular performance measures were compared between obese (body mass index [BMI] ≥95%), overweight (85% ≤BMI <95%), and normal weight subjects (BMI <85%) in a retrospective review of patients with TOF who underwent cardiac magnetic resonance from 2005-2010. Significance was P < .05. Of 260 consecutive patients with TOF, 32 were obese (12.3%), 48 were overweight (18.5%), and 180 were normal weight (69.2%). Biventricular mass was increased in obese compared with normal weight patients with right ventricular mass more affected than left ventricular mass. Obese patients demonstrated decreased biventricular end-diastolic volume (EDV) and stroke volume (SV) when indexed to body surface area (BSA) with an increased heart rate when compared with normal weight patients; cardiac index, ejection fraction, and pulmonary regurgitation fraction were similar. When indexed to ideal BSA, biventricular EDV and SV were similar. EDV and SV for overweight patients were nearly identical to normal weight patients with ventricular mass in between the other 2 groups. Approximately 12% of patients after TOF repair referred for cardiac magnetic resonance in a tertiary referral center are obese with increased biventricular mass. Obese patients and normal weight patients have similar cardiac indices, however, when indexed to actual BSA, obese patients demonstrate decreased EDV and SV with increased heart rate and similar cardiac indices. When indexed to ideal BSA, no differences in biventricular volumes were noted. Copyright © 2015. Published by Elsevier Inc.

The role of conductivity discontinuities in design of cardiac defibrillation

NASA Astrophysics Data System (ADS)

Lim, Hyunkyung; Cun, Wenjing; Wang, Yue; Gray, Richard A.; Glimm, James

2018-01-01

Fibrillation is an erratic electrical state of the heart, of rapid twitching rather than organized contractions. Ventricular fibrillation is fatal if not treated promptly. The standard treatment, defibrillation, is a strong electrical shock to reinitialize the electrical dynamics and allow a normal heart beat. Both the normal and the fibrillatory electrical dynamics of the heart are organized into moving wave fronts of changing electrical signals, especially in the transmembrane voltage, which is the potential difference between the cardiac cellular interior and the intracellular region of the heart. In a normal heart beat, the wave front motion is from bottom to top and is accompanied by the release of Ca ions to induce contractions and pump the blood. In a fibrillatory state, these wave fronts are organized into rotating scroll waves, with a centerline known as a filament. Treatment requires altering the electrical state of the heart through an externally applied electrical shock, in a manner that precludes the existence of the filaments and scroll waves. Detailed mechanisms for the success of this treatment are partially understood, and involve local shock-induced changes in the transmembrane potential, known as virtual electrode alterations. These transmembrane alterations are located at boundaries of the cardiac tissue, including blood vessels and the heart chamber wall, where discontinuities in electrical conductivity occur. The primary focus of this paper is the defibrillation shock and the subsequent electrical phenomena it induces. Six partially overlapping causal factors for defibrillation success are identified from the literature. We present evidence in favor of five of these and against one of them. A major conclusion is that a dynamically growing wave front starting at the heart surface appears to play a primary role during defibrillation by critically reducing the volume available to sustain the dynamic motion of scroll waves; in contrast, virtual electrodes occurring at the boundaries of small, isolated blood vessels only cause minor effects. As a consequence, we suggest that the size of the heart (specifically, the surface to volume ratio) is an important defibrillation variable.

Using impedance cardiography to assess left ventricular systolic function via postural change in patients with heart failure.

PubMed

DeMarzo, Arthur P; Calvin, James E; Kelly, Russell F; Stamos, Thomas D

2005-01-01

For the diagnosis and management of heart failure, it would be useful to have a simple point-of-care test for assessing ventricular function that could be performed by a nurse. An impedance cardiography (ICG) parameter called systolic amplitude (SA) can serve as an indicator of left ventricular systolic function (LVSF). This study tested the hypothesis that patients with normal LVSF should have a significant increase in SA in response to an increase in end-diastolic volume caused by postural change from sitting upright to supine, while patients with depressed LVSF associated with heart failure should have a minimal increase or a decrease in SA from upright to supine. ICG data were obtained in 12 patients without heart disease and with normal LVSF and 18 patients with clinically diagnosed heart failure. Consistent with the hypothesis, patients with normal LVSF had a significant increase in SA from upright to supine, whereas heart failure patients had a minimal increase or a decrease in SA from upright to supine. This ICG procedure may be useful for monitoring the trend of patient response to titration of beta blockers and other medications. ICG potentially could be used to detect worsening LVSF and provide a means of measurement for adjusting treatment.

Renal denervation in heart failure with normal left ventricular ejection fraction. Rationale and design of the DIASTOLE (DenervatIon of the renAl Sympathetic nerves in hearT failure with nOrmal Lv Ejection fraction) trial.

PubMed

Verloop, Willemien L; Beeftink, Martine M A; Nap, Alex; Bots, Michiel L; Velthuis, Birgitta K; Appelman, Yolande E; Cramer, Maarten-Jan; Agema, Willem R P; Scholtens, Asbjorn M; Doevendans, Pieter A; Allaart, Cor P; Voskuil, Michiel

2013-12-01

Aim Increasing evidence suggests an important role for hyperactivation of the sympathetic nervous system (SNS) in the clinical phenomena of heart failure with normal LVEF (HFNEF) and hypertension. Moreover, the level of renal sympathetic activation is directly related to the severity of heart failure. Since percutaneous renal denervation (pRDN) has been shown to be effective in modulating elevated SNS activity in patients with hypertension, it can be hypothesized that pRDN has a positive effect on HFNEF. The DIASTOLE trial will investigate whether renal sympathetic denervation influences parameters of HFNEF. Methods DIASTOLE is a multicentre, randomized controlled trial. Sixty patients, diagnosed with HFNEF and treated for hypertension, will be randomly allocated in a 1:1 ratio to undergo renal denervation on top of medical treatment (n = 30) or to maintain medical treatment alone (n = 30). The primary objective is to investigate the efficacy of pRDN by means of pulsed wave Doppler echocardiographic parameters. Secondary objectives include safety of pRDN and a comparison of changes in the following parameters after pRDN: LV mass, LV volume, LVEF, and left atrial volume as determined by magnetic resonance imaging. Also, MIBG (metaiodobenzylguanidine) uptake and washout, BNP levels, blood pressure, heart rate variability, exercise capacity, and quality of life will be assessed. Perspective DIASTOLE is a randomized controlled trial evaluating renal denervation as a treatment option for HFNEF. The results of the current trial will provide important information regarding the treatment of HFNEF, and therefore may have major impact on future therapeutic strategies. Trail registration NCT01583881.

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

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.

Intensity-modulated proton therapy further reduces normal tissue exposure during definitive therapy for locally advanced distal esophageal tumors: a dosimetric study.

PubMed

Welsh, James; Gomez, Daniel; Palmer, Matthew B; Riley, Beverly A; Mayankkumar, Amin V; Komaki, Ritsuko; Dong, Lei; Zhu, X Ronald; Likhacheva, Anna; Liao, Zhongxing; Hofstetter, Wayne L; Ajani, Jaffer A; Cox, James D

2011-12-01

We have previously found that ≤ 75% of treatment failures after chemoradiotherapy for unresectable esophageal cancer appear within the gross tumor volume and that intensity-modulated (photon) radiotherapy (IMRT) might allow dose escalation to the tumor without increasing normal tissue toxicity. Proton therapy might allow additional dose escalation, with even lower normal tissue toxicity. In the present study, we compared the dosimetric parameters for photon IMRT with that for intensity-modulated proton therapy (IMPT) for unresectable, locally advanced, distal esophageal cancer. Four plans were created for each of 10 patients. IMPT was delivered using anteroposterior (AP)/posteroanterior beams, left posterior oblique/right posterior oblique (LPO/RPO) beams, or AP/LPO/RPO beams. IMRT was delivered with a concomitant boost to the gross tumor volume. The dose was 65.8 Gy to the gross tumor volume and 50.4 Gy to the planning target volume in 28 fractions. Relative to IMRT, the IMPT (AP/posteroanterior) plan led to considerable reductions in the mean lung dose (3.18 vs. 8.27 Gy, p<.0001) and the percentage of lung volume receiving 5, 10, and 20 Gy (p≤.0006) but did not reduce the cardiac dose. The IMPT LPO/RPO plan also reduced the mean lung dose (4.9 Gy vs. 8.2 Gy, p<.001), the heart dose (mean cardiac dose and percentage of the cardiac volume receiving 10, 20, and 30 Gy, p≤.02), and the liver dose (mean hepatic dose 5 Gy vs. 14.9 Gy, p<.0001). The IMPT AP/LPO/RPO plan led to considerable reductions in the dose to the lung (p≤.005), heart (p≤.003), and liver (p≤.04). Compared with IMRT, IMPT for distal esophageal cancer lowered the dose to the heart, lung, and liver. The AP/LPO/RPO beam arrangement was optimal for sparing all three organs. The dosimetric benefits of protons will need to be tailored to each patient according to their specific cardiac and pulmonary risks. IMPT for esophageal cancer will soon be investigated further in a prospective trial at our institution. Copyright © 2011 Elsevier Inc. All rights reserved.

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 new approach for low-cost noninvasive detection of asymptomatic heart disease at rest.

PubMed

DeMarzo, Arthur P; Calvin, James E

2007-01-01

It would be useful to have an inexpensive, noninvasive point-of-care test for early detection of asymptomatic heart disease. This study used impedance cardiography (ICG) in a new way to assess heart function that did not use stroke volume or cardiac output. There is a model of the ICG dZ/dt waveform that may be used as a template to represent normal heart function. The hypothesis was that a dZ/dt waveform which deviates from that template should indicate heart dysfunction and therefore heart disease. The objective was to assess the accuracy of this new ICG approach, using echocardiography as the standard. Thirty-four outpatients undergoing echocardiographic testing were tested by ICG while sitting upright and supine. All patients had no symptoms or history of a structural or functional heart disorder. Echocardiographic testing showed 17 patients with abnormalities and 17 as normal. ICG testing yielded 16 true positives for heart dysfunction with 1 false negative (sensitivity = 94%) and 17 true negatives with no false positives (specificity = 100%). Considering that the cost, technical skill, and time required for this ICG test are comparable to those of an electrocardiograph, this new approach has potential as a point-of-care screening test for asymptomatic heart disease.

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.

Normalization of respiratory sinus arrhythmia by factoring in tidal volume.

PubMed

Kobayashi, H

1998-09-01

The amplitude of respiratory sinus arrhythmia (RSA) was measured in eight healthy young male students with special reference to the effect of tidal volume (Vt). Under simultaneously controlled respiratory frequency and Vt, the heart rate variability (HRV) of the subjects was measured. While the respiratory frequency was adjusted to either 0.25 or 0.10 Hz, the Vt was controlled at 13 different volumes for each frequency. Linear relationships between RSA amplitude and Vt were observed and close correlations were obtained for 0.25 Hz compared with 0.10 Hz. However, regression equations showed a marked variation among subjects. Furthermore, RSA amplitude was related to vital capacity. Subjects who had lower vital capacity tended to show higher RSA amplitudes at the same Vt. Therefore, the ratio (% Vt) of Vt to vital capacity is a more effective index in normalizing RSA than raw tidal volume. From these results, we have proposed a normalized RSA (RSA amplitude/% Vt) as a new index of autonomic activity that provides a constant value regardless of Vt.

A Five-Dimensional Mathematical Model for Regional and Global Changes in Cardiac Uptake and Motion

NASA Astrophysics Data System (ADS)

Pretorius, P. H.; King, M. A.; Gifford, H. C.

2004-10-01

The objective of this work was to simultaneously introduce known regional changes in contraction pattern and perfusion to the existing gated Mathematical Cardiac Torso (MCAT) phantom heart model. We derived a simple integral to calculate the fraction of the ellipsoidal volume that makes up the left ventricle (LV), taking into account the stationary apex and the moving base. After calculating the LV myocardium volume of the existing beating heart model, we employed the property of conservation of mass to manipulate the LV ejection fraction to values ranging between 13.5% and 68.9%. Multiple dynamic heart models that differ in degree of LV wall thickening, base-to-apex motion, and ejection fraction, are thus available for use with the existing MCAT methodology. To introduce more complex regional LV contraction and perfusion patterns, we used composites of dynamic heart models to create a central region with little or no motion or perfusion, surrounded by a region in which the motion and perfusion gradually reverts to normal. To illustrate this methodology, the following gated cardiac acquisitions for different clinical situations were simulated analytically: 1) reduced regional motion and perfusion; 2) same perfusion as in (1) without motion intervention; and 3) washout from the normal and diseased myocardial regions. Both motion and perfusion can change dynamically during a single rotation or multiple rotations of a simulated single-photon emission computed tomography acquisition system.

Creation of dialysis vascular access with normal flow increases brain natriuretic peptide levels.

PubMed

Malík, Jan; Tuka, Vladimir; Krupickova, Zdislava; Chytilova, Eva; Holaj, Robert; Slavikova, Marcela

2009-12-01

Chronic heart failure is very common in hemodialyzed patients due to several factors such as intermittent volume overload, anemia, and hypertension. Dialysis access flow is usually considered to have a minor effect. We hypothesized that creation of dialysis access with "normal" flow would lead to elevation of B-type natriuretic peptide (BNP), which is a sensitive marker of heart failure. We included subjects with a newly created, well-functioning vascular access and normal left ventricular ejection fraction. They were examined before access creation (baseline), then again 6 weeks and 6 months after the surgery. Only subjects with access flow (Qa) < 1500 ml/min were included. Changes of BNP levels and their relation to access flow were studied. We examined 35 subjects aged 60.6 +/- 13.5 years. Qa was 789 +/- 361 and 823 +/- 313 ml/min at 6 weeks and 6 months after the surgery, respectively. Within 6 weeks after access creation, BNP rose from 217 (294) to 267 (550) ng/l (median (quartile range)) with P = 0.003. Qa was significantly related to BNP levels 6 weeks after access creation (r = 0.37, P = 0.036). Six months after access creation, there was only a trend of BNP decrease (235 (308) ng/l, P = 0.44). Creatinine, blood urea nitrogen and hemoglobin levels as well as patients' weight did not change significantly. Creation of dialysis access with "normal" flow volume leads to significant increase of BNP, which is related to the value of access flow. The increase of BNP probably mirrors worsening of clinically silent heart failure.

Simultaneous measurement of instantaneous heart rate and chest wall plethysmography in short-term, metronome guided heart rate variability studies: suitability for assessment of autonomic dysfunction.

PubMed

Perring, S; Jones, E

2003-08-01

Instantaneous heart rate and chest wall motion were measured using a 3-lead ECG and an air pressure chest wall plethysmography system. Chest wall plethysmography traces were found to accurately represent the breathing pattern as measured by spirometry (average correlation coefficient 0.944); though no attempt was made to calibrate plethysmography voltage output to tidal volume. Simultaneous measurements of heart rate and chest wall motion were made for short periods under metronome guided breathing at 6 breaths per minute. The average peak to trough heart rate change per breath cycle (AVEMAX) and maximum correlation between heart rate and breathing cycle (HRBRCORR) were measured. Studies of 44 normal volunteers indicated clear inverse correlation of heart rate variability parameters with age (AVEMAX R = -0.502, P < 0.001) but no significant change in HRBRCORR with age (R = -0.115). Comparison of normal volunteers with diabetics with no history of symptoms associated with autonomic failure indicated significant lower heart rate variability in diabetics (P = 0.005 for AVEMAX) and significantly worse correlation between heart rate and breathing (P < 0.001 for HRBRCORR). Simultaneous measurement of heart rate and breathing offers the possibility of more sensitive diagnosis of autonomic failure in a simple bedside test and gives further insight into the nature of cardio-ventilatory coupling.

Hyperthyroidism as a reversible cause of right ventricular overload and congestive heart failure

PubMed Central

Di Giovambattista, Raniero

2008-01-01

We describe a case of severe congestive heart failure and right ventricular overload associated with overt hyperthyroidism, completely reversed with antithyroid therapy in a few week. It represents a very unusual presentation of overt hyperthyroidism because of the severity of right heart failure. The impressive right ventricular volume overload made mandatory to perform transesophageal echo and angio-TC examination to exclude the coexistence of ASD or anomalous pulmonary venous return. Only a few cases of reversible right heart failure, with or without pulmonary hypertension, have been reported worldwide. In our case the most striking feature has been the normalization of the cardiovascular findings after six weeks of tiamazole therapy. PMID:18549503

iPhysioMeter: a new approach for measuring heart rate and normalized pulse volume using only a smartphone.

PubMed

Matsumura, Kenta; Yamakoshi, Takehiro

2013-12-01

Heart rate (HR) and normalized pulse volume (NPV) are physiological indices that have been used in a diversity of psychological studies. However, measuring these indices often requires laborious processes. We therefore developed a new smartphone program, named iPhysioMeter, that makes it possible to measure beat-by-beat HR and ln NPV using only a smartphone. We examined its accuracy against conventional laboratory measures. Mental stress tasks were used to alter HR and ln NPV in 12 participants. Bland-Altman analyses revealed negligible proportional bias for HR and ln NPV or for their change values, expressed as ΔHR and Δln NPV. However, a relatively large fixed bias did emerge for ln NPV, as well as a small one for Δln NPV, although both were within the limits of agreement. These findings suggest that iPhysioMeter can yield valid measures of the absolute level of HR and of relative changes in ln NPV.

Microgravity

NASA Image and Video Library

1998-01-01

The heart of the bioreactor is the rotating wall vessel, shown without its support equipment. Volume is about 125 mL. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

NASA Bioreactor

NASA Technical Reports Server (NTRS)

1998-01-01

The heart of the bioreactor is the rotating wall vessel, shown without its support equipment. Volume is about 125 mL. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

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.

The influence of emotional stress on Doppler-derived aortic peak velocity in boxer dogs.

PubMed

Pradelli, D; Quintavalla, C; Crosta, M C; Mazzoni, L; Oliveira, P; Scotti, L; Brambilla, P; Bussadori, C

2014-01-01

Subaortic stenosis (SAS) is a common congenital heart disease in Boxers. Doppler-derived aortic peak velocity (AoPV) is a diagnostic criterion for the disease. To investigate the influence of emotional stress during echocardiographic examination on AoPV in normal and SAS-affected Boxers. To evaluate the effects of aortic root diameters on AoPV in normal Boxers. DOGS: Two hundred and fifteen normal and 19 SAS-affected Boxers. The AoPV was recorded at the beginning of echocardiographic examination (T0), and when the emotional stress of the dog was assumed to decrease based on behavioral parameters and heart rate (T1). AoPV0-AoPV1 was calculated. In normal dogs, stroke volume index was calculated at T0 and T1. Aortic root diameters were measured and their relationship with AoPV and AoPV0-AoPV1 was evaluated. In normal dogs, AoPV was higher at T0 (median, 1.95 m/s; range, 1.60-2.50 m/s) than at T1 (median, 1.76 m/s; range, 1.40-2.20 m/s; P < .0001; reduction 9.2%). The stroke volume index at T0 also was greater than at T1 (P < .0001). Weak negative correlations were detected between aortic root size and aortic velocities. In SAS-affected dogs, AoPV0 was higher than AoPV1 (P < .0001; reduction 7.3%). Aortic peak velocity was affected by emotional stress during echocardiographic examination both in SAS-affected and normal Boxers. In normal Boxers, aortic root size weakly affected AoPVs, but did not affect AoPV0-AoPV1. Stroke volume seems to play a major role in stress-related AoPV increases in normal Boxers. Emotional stress should be taken into account when screening for SAS in the Boxer breed. Copyright © 2014 by the American College of Veterinary Internal Medicine.

A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles

PubMed Central

Choi, Young Joon; Constantino, Jason; Vedula, Vijay; Trayanova, Natalia; Mittal, Rajat

2015-01-01

A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier–Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications. PMID:26442254

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.

Clinical applications of angiocardiography

NASA Technical Reports Server (NTRS)

Dodge, H. T.; Sandler, H.

1974-01-01

Several tables are presented giving left ventricular (LV) data for normal patients and patients with heart disease of varied etiologies, pointing out the salient features. Graphs showing LV pressure-volume relationships (compliance) are presented and discussed. The method developed by Rackley et al. (1964) for determining left ventricular mass in man is described, and limitations to the method are discussed. Some clinical methods for determining LV oxygen consumption are briefly described, and the relation of various abnormalities of ventricular performance to coronary artery disease and ischemic heart disease is characterized.

MRI-based evidence for myocardial involvement in women with hypereosinophilic syndrome.

PubMed

Miszalski-Jamka, Tomasz; Szczeklik, Wojciech; Karwat, Krzysztof; Sokołowska, Barbara; Gąsior, Jolanta; Rucińska, Małgorzata; Mazur, Wojciech; Skotnicki, Aleksander; Kereiakes, Dean J; Urbańczyk, Małgorzata; Jaźwiec, Przemysław; Musiał, Jacek

2015-01-01

The aim of the study was to assess the presence and spectrum of cardiac abnormalities identified by cardiac magnetic resonance (CMR) in women with hypereosinophilic syndrome (HES) of undefined etiology, who present with normal electrocardiography (ECG) and transthoracic echocardiography (TTE) and no history of heart disease. Ten women (mean age, 48 ± 14 years) with HES of undefined etiology, normal ECG and TTE, and no history of heart disease underwent CMR. CMR showed cardiac abnormalities in 6 subjects. Five patients had nonischemic late gadolinium enhancement (LGE) lesions within the left ventricular (LV) myocardium, and 3 patients demonstrated CMR evidence of myocardial inflammation. The LV ejection fraction was 68.5 ± 5.7%, and the end-diastolic volume index was 62.7 ± 14.7 mL/m(2). The maximum measured blood eosinophil count correlated with LVLGE volume (r = 0.80, P = 0.006) and was 11374 ± 6242 cells/μL and 4114 ± 2972 cells/μL (P = 0.047) in patients with and without LGE lesions, respectively. The actual blood eosinophil count in subjects with and without CMR evidence of myocarditis was 1058 ± 520 cells/μL and 354 ± 377 cells/μL (P = 0.04), respectively. Despite normal ECG, TTE, and absence of history of heart disease, women with HES of unknown etiology frequently demonstrate cardiac abnormalities on CMR, the presence and extent of which are related to blood eosinophil count.

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.

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.

Four-dimensional ultrasonography of the fetal heart using color Doppler spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Romero, Roberto; Espinoza, Jimmy; Lee, Wesley; Treadwell, Marjorie; Chintala, Kavitha; Brandl, Helmut; Chaiworapongsa, Tinnakorn

2004-04-01

To describe clinical and research applications of 4-dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. Forty-four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double-inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7-34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume-rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.

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.

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.

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.

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.

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

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

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.

Enhancing ejection fraction measurement through 4D respiratory motion compensation in cardiac PET imaging

NASA Astrophysics Data System (ADS)

Tang, Jing; Wang, Xinhui; Gao, Xiangzhen; Segars, W. Paul; Lodge, Martin A.; Rahmim, Arman

2017-06-01

ECG gated cardiac PET imaging measures functional parameters such as left ventricle (LV) ejection fraction (EF), providing diagnostic and prognostic information for management of patients with coronary artery disease (CAD). Respiratory motion degrades spatial resolution and affects the accuracy in measuring the LV volumes for EF calculation. The goal of this study is to systematically investigate the effect of respiratory motion correction on the estimation of end-diastolic volume (EDV), end-systolic volume (ESV), and EF, especially on the separation of normal and abnormal EFs. We developed a respiratory motion incorporated 4D PET image reconstruction technique which uses all gated-frame data to acquire a motion-suppressed image. Using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms, we simulated dual-gated myocardial perfusion imaging data for normally and abnormally beating hearts. With and without respiratory motion correction, we measured the EDV, ESV, and EF from the cardiac-gated reconstructed images. For all the phantoms, the estimated volumes increased and the biases significantly reduced with motion correction compared with those without. Furthermore, the improvement of ESV measurement in the abnormally beating heart led to better separation of normal and abnormal EFs. The simulation study demonstrated the significant effect of respiratory motion correction on cardiac imaging data with motion amplitude as small as 0.7 cm. The larger the motion amplitude the more improvement respiratory motion correction brought about on the EF measurement. Using data-driven respiratory gating, we also demonstrated the effect of respiratory motion correction on estimating the above functional parameters from list mode patient data. Respiratory motion correction has been shown to improve the accuracy of EF measurement in clinical cardiac PET imaging.

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

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.

Postural hypocapnic hyperventilation is associated with enhanced peripheral vasoconstriction in postural tachycardia syndrome with normal supine blood flow

PubMed Central

Stewart, Julian M.; Medow, Marvin S.; Cherniack, Neil S.; Natelson, Benjamin H.

2015-01-01

Previous investigations have demonstrated a subset of postural tachycardia syndrome (POTS) patients characterized by normal peripheral resistance and blood volume while supine but thoracic hypovolemia and splanchnic blood pooling while upright secondary to splanchnic hyperemia. Such “normal-flow” POTS patients often demonstrate hypocapnia during orthostatic stress. We studied 20 POTS patients (14–23 yr of age) and compared them with 10 comparably aged healthy volunteers. We measured changes in heart rate, blood pressure, heart rate and blood pressure variability, arm and leg strain-gauge occlusion plethysmography, respiratory impedance plethysmography calibrated against pneumotachography, end-tidal partial pressure of carbon dioxide (PetCO2), and impedance plethysmographic indexes of blood volume and blood flow within the thoracic, splanchnic, pelvic (upper leg), and lower leg regional circulations while supine and during upright tilt to 70°. Ten POTS patients demonstrated significant hyperventilation and hypocapnia (POTSHC) while 10 were normocapnic with minimal increase in postural ventilation, comparable to control. While relative splanchnic hypervolemia and hyperemia occurred in both POTS groups compared with controls, marked enhancement in peripheral vasoconstriction occurred only in POTSHC and was related to thoracic blood flow. Variability indexes suggested enhanced sympathetic activation in POTSHC compared with other subjects. The data suggest enhanced cardiac and peripheral sympathetic excitation in POTSHC. PMID:16565300

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

The role of exercise testing in heart failure.

PubMed

Swedberg, K; Gundersen, T

1993-01-01

The objectives of exercise testing in congestive heart failure (CHF) may be summarized as follows: (a) detect impaired cardiac performance, (b) grade severity of cardiac failure and classify functional capability, and (c) assess effects of interventions. Several different methods are available to make these assessments, and we have to ask ourselves how well exercise testing achieves these objectives. It has to be kept in mind that the power generated by the exercising muscles is dependent on the oxygen delivery to the skeletal muscles. Oxygen uptake is the result of an integrated performance of the lungs, heart, and peripheral circulation. In patients, as well as in normal subjects, oxygen uptake is related to hemodynamic indices such as cardiac output, stroke volume, or exercise duration when a stepwise regulated maximal exercise protocol is used. However, there are major differences in the concept of a true maximum in normal subjects versus heart failure patients. Fit-normal subjects will achieve a real maximal oxygen uptake, whereas patients may stop testing before a maximum is reached because of symptoms such as dyspnea or leg fatigue. Therefore, it is better if the actual oxygen uptake can be measured. "Peak" rather than true maximal oxygen uptake has been suggested for the classification of the severity of heart failure. Peripheral factors modify the cardiac output through such factors as vascular resistance, organ function, and hormonal release. Maximal exercise will stress the cardiovascular system to a point where the weakest chain will impose a limiting effect.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

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

The human cardiovascular system in the absence of gravity

NASA Technical Reports Server (NTRS)

Bungo, M. W.; Charles, J. B.

1985-01-01

The data collected from a Space Shuttle crew to investigate cardiovascular changes due to microgravity are presented. The experimental procedures which involved preflight, immediate postflight, and one week following postflight echocardiograms of 13 individuals are described. The immediate postflight results reveal a 20 percent decrease in stroke volume, a 16 percent decrease in left ventricular diastolic volume index (LVDVI), no change in systolic volume, blood pressure, or cardiac index, and a 24 percent increase in heart rate. One week later a 17 percent stroke volume increase, a 29 percent increase in cardiac index, and normal blood pressure, and LVDVI were observed. It is concluded that upon reexposure to gravity a readaptation process for the cardiovascular system occurs.

SU-E-T-300: Dosimetric Comparision of 4D Radiation Therapy and 3D Radiation Therapy for the Liver Tumor Based On 4D Medical Image

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

Ma, C; Yin, Y

Purpose: The purpose of this work was to determine the dosimetric benefit to normal tissues by tracking liver tumor dose in four dimensional radiation therapy (4DRT) on ten phases of four dimensional computer tomagraphy(4DCT) images. Methods: Target tracking each phase with the beam aperture for ten liver cancer patients were converted to cumulative plan and compared to the 3D plan with a merged target volume based on 4DCT image in radiation treatment planning system (TPS). The change in normal tissue dose was evaluated in the plan by using the parameters V5, V10, V15, V20,V25, V30, V35 and V40 (volumes receivingmore » 5, 10, 15, 20, 25, 30, 35 and 40Gy, respectively) in the dose-volume histogram for the liver; mean dose for the following structures: liver, left kidney and right kidney; and maximum dose for the following structures: bowel, duodenum, esophagus, stomach and heart. Results: There was significant difference between 4D PTV(average 115.71cm3 )and ITV(169.86 cm3). When the planning objective is 95% volume of PTV covered by the prescription dose, the mean dose for the liver, left kidney and right kidney have an average decrease 23.13%, 49.51%, and 54.38%, respectively. The maximum dose for bowel, duodenum,esophagus, stomach and heart have an average decrease 16.77%, 28.07%, 24.28%, 4.89%, and 4.45%, respectively. Compared to 3D RT, radiation volume for the liver V5, V10, V15, V20, V25, V30, V35 and V40 by using the 4D plans have a significant decrease(P≤0.05). Conclusion: The 4D plan method creates plans that permit better sparing of the normal structures than the commonly used ITV method, which delivers the same dosimetric effects to the target.« less

Effect of streptozotocin-induced diabetes on left ventricular function in adult rats: an in vivo Pinhole Gated SPECT study

PubMed Central

Cosyns, Bernard; Droogmans, Steven; Weytjens, Caroline; Lahoutte, Tony; Van Camp, Guy; Schoors, Danny; Franken, Philippe R

2007-01-01

Background Recent studies have suggested that diabetes mellitus (DM) may cause left ventricular (LV) dysfunction directly resulting in increased susceptibility to heart failure. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The present study was aimed to assess this new imaging technique for quantifying LV function and remodeling from the Streptozotocin (STZ) rat model compared to controls. Methods Twenty one rats were randomly assigned to control or diabetic group. Six months after the induction of diabetes by STZ, Pinhole 99 m Tc-sestamibi gated SPECT was performed for determining rat LV volumes and function. Post-mortem histopathologic analysis was performed to evaluate the determinant of LV remodeling in this model. Results After six months, the normalized to body weight LV End-systolic volume was significantly different in diabetic rats compared to controls (0.46 ± 0.02 vs 0.33 ± 0.03 μL/g; p = 0.01). The normalized LV End-diastolic volume was also different in both groups (1.51 ± 0.03 vs 0.88 ± 0.05 μL/g; p = 0.001) and the normalized stroke volume was significantly higher in STZ-rats (1.05 ± 0.02 vs 0.54 ± 0.06 μL/g; p = 0.001). The muscular fibers were thinner at histology in the diabetic rats (0.44 ± 0.07 vs 0.32 ± 0.06 AU; p = 0.01). Conclusion Pinhole 99 m Tc-sestamibi gated SPECT can successfully be applied for the evaluation of cardiac function and remodeling in STZ-induced diabetic rats. In this model, LV volumes were significantly changed compared to a control population, leading to a LV dysfunction. These findings were consistent with the histopathological abnormalities. Finally, these data further suggest the presence of diabetes cardiomyopathy. PMID:17937784

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

Hippocampal damage and memory impairment in congenital cyanotic heart disease

PubMed Central

Hoskote, Aparna; Chadwick, Martin J.; Dzieciol, Anna M.; Gadian, David G.; Chong, Kling; Banks, Tina; de Haan, Michelle; Baldeweg, Torsten; Mishkin, Mortimer; Vargha‐Khadem, Faraneh

2017-01-01

ABSTRACT Neonatal hypoxia can lead to hippocampal atrophy, which can lead, in turn, to memory impairment. To test the generalizability of this causal sequence, we examined a cohort of 41 children aged 8‐16, who, having received the arterial switch operation to correct for transposition of the great arteries, had sustained significant neonatal cyanosis but were otherwise neurodevelopmentally normal. As predicted, the cohort had significant bilateral reduction of hippocampal volumes relative to the volumes of 64 normal controls. They also had significant, yet selective, impairment of episodic memory as measured by standard tests of memory, despite relatively normal levels of intelligence, academic attainment, and verbal fluency. Across the cohort, degree of memory impairment was correlated with degree of hippocampal atrophy suggesting that even as early as neonatal life no other structure can fully compensate for hippocampal injury and its special role in serving episodic long term memory. © 2017 Wiley Periodicals, Inc. PMID:28032672

Sacubitril/Valsartan in an Elderly Patient with Heart Failure: A Case Report.

PubMed

Cameli, Matteo; Pastore, Maria Concetta; Pagliaro, Antonio; Di Tommaso, Cristina; Reccia, Rosanna; Curci, Valeria; Mandoli, Giulia Elena; Mondillo, Sergio

2017-01-01

Sacubitril/valsartan has recently been approved for the treatment of heart failure with reduced ejection fraction. Given its recent introduction in the armamentarium for the treatment of heart failure (HF), "field-practice" evidence is required to deepen the clinical management of sacubitril/valsartan therapy. We report a relevant case of an elderly patient who achieved major clinical benefits after only 3 months of sacubitril/valsartan therapy. Importantly, in our assessment, we employed speckle tracking echocardiography (STE), a recent echocardiography technique that is non-Doppler and not angle dependent, which analyzes deformations of heart chambers from standard images and allows a fast, reliable, and reproducible assessment of heart function. After 3 months of therapy, NHYA class decreased from III to I-II and hypertension was controlled. Echocardiography examination also showed a marked improvement, with a reduction of left ventricular diameter, improved diastolic function (E = 0.39 m/s; A 0.69 m/s; E/A 0.55), normalized diastolic function index (E/E' TDI = 6.93), normalized atrial volume (63 mL), and improved atrial strain (15.44%). This case report documents the fast clinical and symptom improvement with sacubitril/valsartan in an elderly patient with HF; comprehensive echocardiographic assessment, including STE, also revealed a marked functional improvement with this compound. © 2017 S. Karger AG, Basel.

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

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

Cardiac damage in athlete's heart: When the "supernormal" heart fails!

PubMed

Carbone, Andreina; D'Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-06-26

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete's blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete's heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded.

Origins and consequences of congenital heart defects affecting the right ventricle.

PubMed

Woudstra, Odilia I; Ahuja, Suchit; Bokma, Jouke P; Bouma, Berto J; Mulder, Barbara J M; Christoffels, Vincent M

2017-10-01

Congenital heart disease is a major health issue, accounting for a third of all congenital defects. Improved early surgical management has led to a growing population of adults with congenital heart disease, including patients with defects affecting the right ventricle, which are often classified as severe. Defects affecting the right ventricle often cause right ventricular volume or pressure overload and affected patients are at high risk for complications such as heart failure and sudden death. Recent insights into the developmental mechanisms and distinct developmental origins of the left ventricle, right ventricle, and the outflow tract have shed light on the common features and distinct problems arising in specific defects. Here, we provide a comprehensive overview of the current knowledge on the development into the normal and congenitally malformed right heart and the clinical consequences of several congenital heart defects affecting the right ventricle. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Cardiac damage in athlete’s heart: When the “supernormal” heart fails!

PubMed Central

Carbone, Andreina; D’Andrea, Antonello; Riegler, Lucia; Scarafile, Raffaella; Pezzullo, Enrica; Martone, Francesca; America, Raffaella; Liccardo, Biagio; Galderisi, Maurizio; Bossone, Eduardo; Calabrò, Raffaele

2017-01-01

Intense exercise may cause heart remodeling to compensate increases in blood pressure or volume by increasing muscle mass. Cardiac changes do not involve only the left ventricle, but all heart chambers. Physiological cardiac modeling in athletes is associated with normal or enhanced cardiac function, but recent studies have documented decrements in left ventricular function during intense exercise and the release of cardiac markers of necrosis in athlete’s blood of uncertain significance. Furthermore, cardiac remodeling may predispose athletes to heart disease and result in electrical remodeling, responsible for arrhythmias. Athlete’s heart is a physiological condition and does not require a specific treatment. In some conditions, it is important to differentiate the physiological adaptations from pathological conditions, such as hypertrophic cardiomyopathy, arrhythmogenic dysplasia of the right ventricle, and non-compaction myocardium, for the greater risk of sudden cardiac death of these conditions. Moreover, some drugs and performance-enhancing drugs can cause structural alterations and arrhythmias, therefore, their use should be excluded. PMID:28706583

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

FAST (Four chamber view And Swing Technique) Echo: a Novel and Simple Algorithm to Visualize Standard Fetal Echocardiographic Planes

PubMed Central

Yeo, Lami; Romero, Roberto; Jodicke, Cristiano; Oggè, Giovanna; Lee, Wesley; Kusanovic, Juan Pedro; Vaisbuch, Edi; Hassan, Sonia S.

2010-01-01

Objective To describe a novel and simple algorithm (FAST Echo: Four chamber view And Swing Technique) to visualize standard diagnostic planes of fetal echocardiography from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView). Methods We developed an algorithm to image standard fetal echocardiographic planes by drawing four dissecting lines through the longitudinal view of the ductal arch contained in a STIC volume dataset. Three of the lines are locked to provide simultaneous visualization of targeted planes, and the fourth line (unlocked) “swings” through the ductal arch image (“swing technique”), providing an infinite number of cardiac planes in sequence. Each line generated the following plane(s): 1) Line 1: three-vessels and trachea view; 2) Line 2: five-chamber view and long axis view of the aorta (obtained by rotation of the five-chamber view on the y-axis); 3) Line 3: four-chamber view; and 4) “Swing” line: three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach. The algorithm was then tested in 50 normal hearts (15.3 – 40 weeks of gestation) and visualization rates for cardiac diagnostic planes were calculated. To determine if the algorithm could identify planes that departed from the normal images, we tested the algorithm in 5 cases with proven congenital heart defects. Results In normal cases, the FAST Echo algorithm (3 locked lines and rotation of the five-chamber view on the y-axis) was able to generate the intended planes (longitudinal view of the ductal arch, pulmonary artery, three-vessels and trachea view, five-chamber view, long axis view of the aorta, four-chamber view): 1) individually in 100% of cases [except for the three-vessel and trachea view, which was seen in 98% (49/50)]; and 2) simultaneously in 98% (49/50). The “swing technique” was able to generate the three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach in 100% of normal cases. In the abnormal cases, the FAST Echo algorithm demonstrated the cardiac defects and displayed views that deviated from what was expected from the examination of normal hearts. The “swing technique” was useful in demonstrating the specific diagnosis due to visualization of an infinite number of cardiac planes in sequence. Conclusions This novel and simple algorithm can be used to visualize standard fetal echocardiographic planes in normal fetal hearts. The FAST Echo algorithm may simplify examination of the fetal heart and could reduce operator dependency. Using this algorithm, the inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease. PMID:20878671

Four-chamber view and 'swing technique' (FAST) echo: a novel and simple algorithm to visualize standard fetal echocardiographic planes.

PubMed

Yeo, L; Romero, R; Jodicke, C; Oggè, G; Lee, W; Kusanovic, J P; Vaisbuch, E; Hassan, S

2011-04-01

To describe a novel and simple algorithm (four-chamber view and 'swing technique' (FAST) echo) for visualization of standard diagnostic planes of fetal echocardiography from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView). We developed an algorithm to image standard fetal echocardiographic planes by drawing four dissecting lines through the longitudinal view of the ductal arch contained in a STIC volume dataset. Three of the lines are locked to provide simultaneous visualization of targeted planes, and the fourth line (unlocked) 'swings' through the ductal arch image (swing technique), providing an infinite number of cardiac planes in sequence. Each line generates the following plane(s): (a) Line 1: three-vessels and trachea view; (b) Line 2: five-chamber view and long-axis view of the aorta (obtained by rotation of the five-chamber view on the y-axis); (c) Line 3: four-chamber view; and (d) 'swing line': three-vessels and trachea view, five-chamber view and/or long-axis view of the aorta, four-chamber view and stomach. The algorithm was then tested in 50 normal hearts in fetuses at 15.3-40 weeks' gestation and visualization rates for cardiac diagnostic planes were calculated. To determine whether the algorithm could identify planes that departed from the normal images, we tested the algorithm in five cases with proven congenital heart defects. In normal cases, the FAST echo algorithm (three locked lines and rotation of the five-chamber view on the y-axis) was able to generate the intended planes (longitudinal view of the ductal arch, pulmonary artery, three-vessels and trachea view, five-chamber view, long-axis view of the aorta, four-chamber view) individually in 100% of cases (except for the three-vessels and trachea view, which was seen in 98% (49/50)) and simultaneously in 98% (49/50). The swing technique was able to generate the three-vessels and trachea view, five-chamber view and/or long-axis view of the aorta, four-chamber view and stomach in 100% of normal cases. In the abnormal cases, the FAST echo algorithm demonstrated the cardiac defects and displayed views that deviated from what was expected from the examination of normal hearts. The swing technique was useful for demonstrating the specific diagnosis due to visualization of an infinite number of cardiac planes in sequence. This novel and simple algorithm can be used to visualize standard fetal echocardiographic planes in normal fetal hearts. The FAST echo algorithm may simplify examination of the fetal heart and could reduce operator dependency. Using this algorithm, inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

Comparison of adverse effects of proton and X-ray chemoradiotherapy for esophageal cancer using an adaptive dose–volume histogram analysis

PubMed Central

Makishima, Hirokazu; Ishikawa, Hitoshi; Terunuma, Toshiyuki; Hashimoto, Takayuki; Yamanashi, Koichi; Sekiguchi, Takao; Mizumoto, Masashi; Okumura, Toshiyuki; Sakae, Takeji; Sakurai, Hideyuki

2015-01-01

Cardiopulmonary late toxicity is of concern in concurrent chemoradiotherapy (CCRT) for esophageal cancer. The aim of this study was to examine the benefit of proton beam therapy (PBT) using clinical data and adaptive dose–volume histogram (DVH) analysis. The subjects were 44 patients with esophageal cancer who underwent definitive CCRT using X-rays (n = 19) or protons (n = 25). Experimental recalculation using protons was performed for the patient actually treated with X-rays, and vice versa. Target coverage and dose constraints of normal tissues were conserved. Lung V5–V20, mean lung dose (MLD), and heart V30–V50 were compared for risk organ doses between experimental plans and actual treatment plans. Potential toxicity was estimated using protons in patients actually treated with X-rays, and vice versa. Pulmonary events of Grade ≥2 occurred in 8/44 cases (18%), and cardiac events were seen in 11 cases (25%). Risk organ doses in patients with events of Grade ≥2 were significantly higher than for those with events of Grade ≤1. Risk organ doses were lower in proton plans compared with X-ray plans. All patients suffering toxicity who were treated with X-rays (n = 13) had reduced predicted doses in lung and heart using protons, while doses in all patients treated with protons (n = 24) with toxicity of Grade ≤1 had worsened predicted toxicity with X-rays. Analysis of normal tissue complication probability showed a potential reduction in toxicity by using proton beams. Irradiation dose, volume and adverse effects on the heart and lung can be reduced using protons. Thus, PBT is a promising treatment modality for the management of esophageal cancer. PMID:25755255

Confocal Microscopy-Based Estimation of Parameters for Computational Modeling of Electrical Conduction in the Normal and Infarcted Heart.

PubMed

Greiner, Joachim; Sankarankutty, Aparna C; Seemann, Gunnar; Seidel, Thomas; Sachse, Frank B

2018-01-01

Computational modeling is an important tool to advance our knowledge on cardiac diseases and their underlying mechanisms. Computational models of conduction in cardiac tissues require identification of parameters. Our knowledge on these parameters is limited, especially for diseased tissues. Here, we assessed and quantified parameters for computational modeling of conduction in cardiac tissues. We used a rabbit model of myocardial infarction (MI) and an imaging-based approach to derive the parameters. Left ventricular tissue samples were obtained from fixed control hearts (animals: 5) and infarcted hearts (animals: 6) within 200 μm (region 1), 250-750 μm (region 2) and 1,000-1,250 μm (region 3) of the MI border. We assessed extracellular space, fibroblasts, smooth muscle cells, nuclei and gap junctions by a multi-label staining protocol. With confocal microscopy we acquired three-dimensional (3D) image stacks with a voxel size of 200 × 200 × 200 nm. Image segmentation yielded 3D reconstructions of tissue microstructure, which were used to numerically derive extracellular conductivity tensors. Volume fractions of myocyte, extracellular, interlaminar cleft, vessel and fibroblast domains in control were (in %) 65.03 ± 3.60, 24.68 ± 3.05, 3.95 ± 4.84, 7.71 ± 2.15, and 2.48 ± 1.11, respectively. Volume fractions in regions 1 and 2 were different for myocyte, myofibroblast, vessel, and extracellular domains. Fibrosis, defined as increase in fibrotic tissue constituents, was (in %) 21.21 ± 1.73, 16.90 ± 9.86, and 3.58 ± 8.64 in MI regions 1, 2, and 3, respectively. For control tissues, image-based computation of longitudinal, transverse and normal extracellular conductivity yielded (in S/m) 0.36 ± 0.11, 0.17 ± 0.07, and 0.1 ± 0.06, respectively. Conductivities were markedly increased in regions 1 ( + 75 , + 171, and + 100%), 2 ( + 53 , + 165, and + 80%), and 3 ( + 42 , + 141, and + 60%) . Volume fractions of the extracellular space including interlaminar clefts strongly correlated with conductivities in control and MI hearts. Our study provides novel quantitative data for computational modeling of conduction in normal and MI hearts. Notably, our study introduces comprehensive statistical information on tissue composition and extracellular conductivities on a microscopic scale in the MI border zone. We suggest that the presented data fill a significant gap in modeling parameters and extend our foundation for computational modeling of cardiac conduction.

Fluid Volume Overload and Congestion in Heart Failure: Time to Reconsider Pathophysiology and How Volume Is Assessed.

PubMed

Miller, Wayne L

2016-08-01

Volume regulation, assessment, and management remain basic issues in patients with heart failure. The discussion presented here is directed at opening a reassessment of the pathophysiology of congestion in congestive heart failure and the methods by which we determine volume overload status. Peer-reviewed historical and contemporary literatures are reviewed. Volume overload and fluid congestion remain primary issues for patients with chronic heart failure. The pathophysiology is complex, and the simple concept of intravascular fluid accumulation is not adequate. The dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to central pulmonary circulation need to be taken into account in strategies of volume management. Clinical bedside evaluations and right heart hemodynamic assessments can alert clinicians of changes in volume status, but only the quantitative measurement of total blood volume can help identify the heterogeneity in plasma volume and red blood cell mass that are features of volume overload in patients with chronic heart failure and help guide individualized, appropriate therapy-not all volume overload is the same. © 2016 American Heart Association, Inc.

Discussion of Source Reconstruction Models Using 3D MCG Data

NASA Astrophysics Data System (ADS)

Melis, Massimo De; Uchikawa, Yoshinori

In this study we performed the source reconstruction of magnetocardiographic signals generated by the human heart activity to localize the site of origin of the heart activation. The localizations were performed in a four compartment model of the human volume conductor. The analyses were conducted on normal subjects and on a subject affected by the Wolff-Parkinson-White syndrome. Different models of the source activation were used to evaluate whether a general model of the current source can be applied in the study of the cardiac inverse problem. The data analyses were repeated using normal and vector component data of the MCG. The results show that a distributed source model has the better accuracy in performing the source reconstructions, and that 3D MCG data allow finding smaller differences between the different source models.

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.

Baroreflex-Mediated Heart Rate and Vascular Resistance Responses 24 h after Maximal Exercise

DTIC Science & Technology

2003-01-01

of normal physiological function in bedridden patients and astronauts. The implication for failure of CVP and plasma volume to return to baseline... FUNCTION , BLOOD PRES- SURE, CENTRAL VENOUS PRESSURE, PHENYLEPHRINE, NECK PRESSURE, LOWER BODY NEGATIVE PRESSURE, COUNTERMEASURES Increased incidence of...orthostatic hypotension and intol-erance in humans is associated with vascular hypovole-mia and attenuated cardiovascular reflex functions

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

Automatic assessment of mitral regurgitation severity based on extensive textural features on 2D echocardiography videos.

PubMed

Moghaddasi, Hanie; Nourian, Saeed

2016-06-01

Heart disease is the major cause of death as well as a leading cause of disability in the developed countries. Mitral Regurgitation (MR) is a common heart disease which does not cause symptoms until its end stage. Therefore, early diagnosis of the disease is of crucial importance in the treatment process. Echocardiography is a common method of diagnosis in the severity of MR. Hence, a method which is based on echocardiography videos, image processing techniques and artificial intelligence could be helpful for clinicians, especially in borderline cases. In this paper, we introduce novel features to detect micro-patterns of echocardiography images in order to determine the severity of MR. Extensive Local Binary Pattern (ELBP) and Extensive Volume Local Binary Pattern (EVLBP) are presented as image descriptors which include details from different viewpoints of the heart in feature vectors. Support Vector Machine (SVM), Linear Discriminant Analysis (LDA) and Template Matching techniques are used as classifiers to determine the severity of MR based on textural descriptors. The SVM classifier with Extensive Uniform Local Binary Pattern (ELBPU) and Extensive Volume Local Binary Pattern (EVLBP) have the best accuracy with 99.52%, 99.38%, 99.31% and 99.59%, respectively, for the detection of Normal, Mild MR, Moderate MR and Severe MR subjects among echocardiography videos. The proposed method achieves 99.38% sensitivity and 99.63% specificity for the detection of the severity of MR and normal subjects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Is cardiac toxicity a relevant issue in the radiation treatment of esophageal cancer?

PubMed

Beukema, Jannet C; van Luijk, Peter; Widder, Joachim; Langendijk, Johannes A; Muijs, Christina T

2015-01-01

In recent years several papers have been published on radiation-induced cardiac toxicity, especially in breast cancer patients. However, in esophageal cancer patients the radiation dose to the heart is usually markedly higher. To determine whether radiation-induced cardiac toxicity is also a relevant issue for this group, we conducted a review of the current literature. A literature search was performed in Medline for papers concerning cardiac toxicity in esophageal cancer patients treated with radiotherapy with or without chemotherapy. The overall crude incidence of symptomatic cardiac toxicity was as high as 10.8%. Toxicities corresponded with several dose-volume parameters of the heart. The most frequently reported complications were pericardial effusion, ischemic heart disease and heart failure. Cardiac toxicity is a relevant issue in the treatment of esophageal cancer. However, valid Normal Tissue Complication Probability models for esophageal cancer are not available at present. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease.

PubMed

Nakano, Stephanie J; Siomos, Austine K; Garcia, Anastacia M; Nguyen, Hieu; SooHoo, Megan; Galambos, Csaba; Nunley, Karin; Stauffer, Brian L; Sucharov, Carmen C; Miyamoto, Shelley D

2017-12-01

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure. Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression. Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right ventricular function (38%). Fibrosis is not a primary contributor to right ventricular failure in infants and young children with single ventricular heart disease. Additional studies are required to understand whether antifibrotic therapies are beneficial in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients.

PubMed

Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook

2015-03-21

Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

Implant breast reconstruction followed by radiotherapy: Can helical tomotherapy become a standard irradiation treatment?

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

Massabeau, Carole, E-mail: cmassabeau@hotmail.com; Fournier-Bidoz, Nathalie; Wakil, Georges

2012-01-01

To evaluate the benefits and limitations of helical tomotherapy (HT) for loco-regional irradiation of patients after a mastectomy and immediate implant-based reconstruction. Ten breast cancer patients with retropectoral implants were randomly selected for this comparative study. Planning target volumes (PTVs) 1 (the volume between the skin and the implant, plus margin) and 2 (supraclavicular, infraclavicular, and internal mammary nodes, plus margin) were 50 Gy in 25 fractions using a standard technique and HT. The extracted dosimetric data were compared using a 2-tailed Wilcoxon matched-pair signed-rank test. Doses for PTV1 and PTV2 were significantly higher with HT (V95 of 98.91 andmore » 97.91%, respectively) compared with the standard technique (77.46 and 72.91%, respectively). Similarly, the indexes of homogeneity were significantly greater with HT (p = 0.002). HT reduced ipsilateral lung volume that received {>=}20 Gy (16.7 vs. 35%), and bilateral lungs (p = 0.01) and neighboring organs received doses that remained well below tolerance levels. The heart volume, which received 25 Gy, was negligible with both techniques. HT can achieve full target coverage while decreasing high doses to the heart and ipsilateral lung. However, the low doses to normal tissue volumes need to be reduced in future studies.« less

Left ventricular performance in various heart diseases with or without heart failure:--an appraisal by quantitative one-plane cineangiocardiography.

PubMed

Lien, W P; Lee, Y S; Chang, F Z; Chen, J J; Shieh, W B

1978-01-01

Quantitative one-plane cineangiocardiography in right anterior oblique position for evaluation of LV performance was carried out in 62 patients with various heart diseases and in 13 subjects with normal LV. Parameters for evaluating both pump and muscle performances were derived from volume and pressure measurements. Of 31 patients with either systolic hypertension or LV myocardial diseases (coronary artery disease or idiopathic cardiomyopathy), 14 had clinical evidence of LV failure before the study. It was found that mean VCF and EF were most sensitive indicators of impaired LV performance among the various parameters. There was a close correlation between mean VCF and EF, yet discordant changes of both parameters were noted in some patients. Furthermore, wall motion abnormalities were not infrequently observed in patients with coronary artery disease or primary cardiomyopathy. Therefore, assessment of at least three ejection properties (EF, mean VCF and wall motion abnormalities) are considered to be essential for full understanding of derangement of LV function in heart disease. This is especially true of patients with coronary artery disease. LV behavior in relation to different pathological stresses or lesions, such as chronic pressure or volume load, myocardial disease and mitral stenosis, was also studied and possible cause of impaired LV myocardial function in mitral stenosis was discussed.

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.

Systolic ventricular filling.

PubMed

Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

2004-03-01

The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles involved in this action. This contraction occurs during the last part of classical systole and the first part of diastole. Therefore, the most important part of ventricular diastole (i.e. the rapid filling phase), in which it receives >70% of the stroke volume, belongs to the active muscular contraction of the ascendent segment. We hope that these facts will give rise to new understanding of the principal mechanisms involved in normal and abnormal diastolic heart function.

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.

Sleep Disordered Breathing in Patients with Heart Failure: Pathophysiology and Management

PubMed Central

Sharma, Bhavneesh; McSharry, David; Malhotra, Atul

2013-01-01

Opinion statement Sleep disordered breathing (SDB) is common in heart failure patients across the range of ejection fractions and is associated with adverse prognosis. Although effective pharmacologic and device-based treatment of heart failure may reduce the frequency or severity of SDB, heart failure treatment alone may not be adequate to restore normal breathing during sleep. Continuous positive airway pressure (CPAP) is the major treatment for SDB in heart failure, especially if obstructive rather than central sleep apnea (CSA) predominates. Adequate suppression of CSA by PAP is associated with a heart transplant-free survival benefit, although randomized trials are ongoing. Bilevel PAP (BPAP) may be as effective as CPAP in treating SDB and may be preferable over CPAP in patients who experience expiratory pressure discomfort. Adaptive (or auto) servo-ventilation (ASV), which adjusts the PAP depending on the patient’s airflow or tidal volume, may be useful in congestive heart failure patients if CPAP is ineffective. Other therapies that have been proposed for SDB in congestive heart failure include nocturnal oxygen, CO2 administration (by adding dead space), theophylline, and acetazolamide; most of which have not been systematically studied in outcome-based prospective randomized trials. PMID:21894522

The effect of excess expression of GFP in a novel heart-specific green fluorescence zebrafish regulated by nppa enhancer at early embryonic development.

PubMed

Huang, Wen; Deng, Yun; Dong, Wei; Yuan, Wuzhou; Wan, Yongqi; Mo, Xiaoyan; Li, Yongqing; Wang, Zequn; Wang, Yuequn; Ocorr, Karen; Zhang, Bo; Lin, Shuo; Wu, Xiushan

2011-02-01

In order to study the impalpable effect of GFP in homozygous heart-specific GFP-positive zebrafish during the early stage, the researchers analyzed the heart function of morphology and physiology at the first 3 days after fertilization. This zebrafish line was produced by a large-scale Tol2 transposon mediated enhancer trap screen that generated a transgenic zebrafish with a heart-specific expression of green fluorescent protein (GFP)-tagged under control of the nppa enhancer. In situ hybridization experiments showed that the nppa:GFP line faithfully recapitulated both the spatial and temporal expressions of the endogenous nppa. Green fluorescence was intensively and specifically expressed in the myocardial cells located both in the heart chambers and in the atrioventricular canal. The embryonic heart of nppa:GFP line developed normally compared with those in the wild type. There was no difference between the nappa:GFP and wild type lines with respect to heart rate, overall size, ejection volume, and fractional shortening. Thus the excess expression of GFP in this transgenic line seemed to exert no detrimental effects on zebrafish hearts during the early stages.

Tachycardia-Induced Right Heart Failure and Severe Tricuspid Regurgitation That Improved with Medication.

PubMed

Yang, Young Ae; Yang, Dong Heon; Kim, Hong Nyun; Kwon, Sang Hoon; Jang, Se Young; Bae, Myung Hwan; Lee, Jang Hoon; Chae, Shung Chull

2015-12-01

Secondary tricuspid regurgitation (TR) primarily develops due to left heart failure or primary pulmonary diseases. Tricuspid annular dilation, which is commonly caused by right ventricular volume and pressure overload followed by right ventricle dilation, is believed to be the main mechanism underlying secondary TR. It is reported that once the tricuspid annulus is dilated, its size cannot spontaneously return to normal, and it may continue to dilate. These reports also suggest the use of an aggressive surgical approach for secondary TR. In the present report, we describe a case of tachycardia-induced severe TR that was completely resolved without the need for surgery.

Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Benjamin, B. A.; Keil, L. C.; Sandler, H.

1984-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes, designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients, to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of 6 deg headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate and blood pressure were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20 percent (P less than 0.05) with T, and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

Heart rate-induced modifications of concentric left ventricular hypertrophy: exploration of a novel therapeutic concept.

PubMed

Klein, Franziska J; Bell, Stephen; Runte, K Elisabeth; Lobel, Robert; Ashikaga, Takamuru; Lerman, Lilach O; LeWinter, Martin M; Meyer, Markus

2016-10-01

Lowering the heart rate is considered to be beneficial in heart failure (HF) with reduced ejection fraction (HFrEF). In a dilated left ventricle (LV), pharmacological heart rate lowering is associated with a reduction in LV chamber size. In patients with HFrEF, this structural change is associated with better survival. HF with preserved ejection fraction (HFpEF) is increasingly prevalent but, so far, without any evidence-based treatment. HFpEF is typically associated with LV concentric remodeling and hypertrophy. The effects of heart rate on this structural phenotype are not known. Analogous with the benefits of a low heart rate on a dilated heart, we hypothesized that increased heart rates could lead to potentially beneficial remodeling of a concentrically hypertrophied LV. This was explored in an established porcine model of concentric LV hypertrophy and fibrosis. Our results suggest that a moderate increase in heart rate can be used to reduce wall thickness, normalize LV chamber volumes, decrease myocardial fibrosis, and improve LV compliance. Our results also indicate that the effects of heart rate can be titrated, are reversible, and do not induce HF. These findings may provide the rationale for a novel therapeutic approach for HFpEF and its antecedent disease substrate. Copyright © 2016 the American Physiological Society.

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.

Impact of the number of image planes of real-time three-dimensional echocardiography on the accuracy of left atrial and ventricular volume measurements.

PubMed

Li, Fang; Wang, Qian; Yao, Gui Hua; Zhang, Peng Fei; Ge, Zhi Ming; Zhang, Mei; Zhang, Yun

2008-01-01

Real-time three-dimensional (3D) echocardiography (RT-3DE) has emerged as a new technique in measuring left atrial and ventricular volume. However, the impact of cutting planes of RT-3DE on the accuracy of volume measurement in patients with a normal or enlarged heart is still unknown. We enrolled 30 normal subjects (control group) and 30 patients with heart failure (patient group). RT-3DE was performed to measure maximal volume of the left atrium (LAVmax) and left ventricular end-diastole volume (LVEDV) with 2-, 4-, 8- and 16-cutting planes, compared with cardiac magnetic resonance imaging (CMRI). In both groups, LAVmax by RT-3DE using 2- and 4-cutting planes was significantly underestimated (mean difference: -10.4 +/- 16.6 mL, p = 0.001 and -8.8 +/- 14.2 mL, p = 0.002 in the control group and -13.4 +/- 19.6 mL, p = 0.001 and -11.2 +/- 17.5 mL, p = 0.001 in the patient group, respectively). These differences became nonsignificant when 8- and 16-cutting planes were adopted (mean difference: -2.1 +/- 7.6 mL and -1.9 +/- 7.4 mL in the control group and -2.7 +/- 8.4 mL and -2.2 +/- 8.3 mL in the patient group, respectively). The agreement for LVEDV was acceptable when 4- or more cutting planes were used in the control group and when 8- or 16-cutting planes were used in the patient group. The time expense for data analysis of LAVmax with 8-image planes was only 7 +/- 4 min in the control group and 6 +/- 5 min in the patient group, almost halving that of the 16-image planes. Similarly, 4- and 8-cutting planes were required for an accurate measurement of LVEDV in the control and patient groups, respectively. In conclusion, RT-3DE with 8-cutting planes is both accurate and timesaving for measurement of LAVmax and LVEDV in patients with normal or enlarged left atria and ventricles.

Hippocampal damage and memory impairment in congenital cyanotic heart disease.

PubMed

Muñoz-López, Mónica; Hoskote, Aparna; Chadwick, Martin J; Dzieciol, Anna M; Gadian, David G; Chong, Kling; Banks, Tina; de Haan, Michelle; Baldeweg, Torsten; Mishkin, Mortimer; Vargha-Khadem, Faraneh

2017-04-01

Neonatal hypoxia can lead to hippocampal atrophy, which can lead, in turn, to memory impairment. To test the generalizability of this causal sequence, we examined a cohort of 41 children aged 8-16, who, having received the arterial switch operation to correct for transposition of the great arteries, had sustained significant neonatal cyanosis but were otherwise neurodevelopmentally normal. As predicted, the cohort had significant bilateral reduction of hippocampal volumes relative to the volumes of 64 normal controls. They also had significant, yet selective, impairment of episodic memory as measured by standard tests of memory, despite relatively normal levels of intelligence, academic attainment, and verbal fluency. Across the cohort, degree of memory impairment was correlated with degree of hippocampal atrophy suggesting that even as early as neonatal life no other structure can fully compensate for hippocampal injury and its special role in serving episodic long term memory. © 2017 Wiley Periodicals, Inc. © 2017 The Authors. Hippocampus Published by Wiley Periodicals, Inc.

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.

The forgotten role of central volume in low frequency oscillations of heart rate variability.

PubMed

Ferrario, Manuela; Moissl, Ulrich; Garzotto, Francesco; Cruz, Dinna N; Tetta, Ciro; Signorini, Maria G; Ronco, Claudio; Grassmann, Aileen; Cerutti, Sergio; Guzzetti, Stefano

2015-01-01

The hypothesis that central volume plays a key role in the source of low frequency (LF) oscillations of heart rate variability (HRV) was tested in a population of end stage renal disease patients undergoing conventional hemodialysis (HD) treatment, and thus subject to large fluid shifts and sympathetic activation. Fluid overload (FO) in 58 chronic HD patients was assessed by whole body bioimpedance measurements before the midweek HD session. Heart Rate Variability (HRV) was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. Time domain and frequency domain analyses were performed on HRV signals. Patients were retrospectively classified in three groups according to tertiles of FO normalized to the extracellular water (FO/ECW%). These groups were also compared after stratification by diabetes mellitus. Patients with the low to medium hydration status before the treatment (i.e. 1st and 2nd FO/ECW% tertiles) showed a significant increase in LF power during last 30 min of HD compared to dialysis begin, while no significant change in LF power was seen in the third group (i.e. those with high pre-treatment hydration values). In conclusion, several mechanisms can generate LF oscillations in the cardiovascular system, including baroreflex feedback loops and central oscillators. However, the current results emphasize the role played by the central volume in determining the power of LF oscillations.

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.

Vagal Nerve Stimulation Evoked Heart Rate Changes and Protection from Cardiac Remodeling.

PubMed

Agarwal, Rahul; Mokelke, Eric; Ruble, Stephen B; Stolen, Craig M

2016-02-01

This study investigated whether vagal nerve stimulation (VNS) leads to improvements in ischemic heart failure via heart rate modulation. At 7 ± 1 days post left anterior descending artery (LAD) ligation, 63 rats with myocardial infarctions (MI) were implanted with ECG transmitters and VNS devices (MI + VNS, N = 44) or just ECG transmitters (MI, N = 17). VNS stimulation was active from 14 ± 1 days to 8 ± 1 weeks post MI. The average left ventricular (LV) end diastolic volumes at 8 ± 1 weeks were MI = 672.40 μl and MI + VNS = 519.35 μl, p = 0.03. The average heart weights, normalized to body weight (± std) at 14 ± 1 weeks were MI = 3.2 ± 0.6 g*kg(-1) and MI + VNS = 2.9 ± 0.3 g*kg(-1), p = 0.03. The degree of cardiac remodeling was correlated with the magnitude of acute VNS-evoked heart rate (HR) changes. Further research is required to determine if the acute heart rate response to VNS activation is useful as a heart failure biomarker or as a tool for VNS therapy characterization.

Active Breathing Control for Hodgkin's Disease in Childhood and Adolescence: Feasibility, Advantages, and Limits

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

Claude, Line; Malet, Claude Phys.; Pommier, Pascal

2007-04-01

Purpose: The challenge in early Hodgkin's disease (HD) in children is to maintain good survival rates while sparing organs at risk. This study assesses the feasibility of active breathing control (ABC) in children, and compares normal tissue irradiation with and without ABC. Methods and Materials: Between May 2003 and June 2004, seven children with HD with mediastinal involvement, median age 15, were treated by chemotherapy and involved-field radiation therapy. A free-breathing computed tomography simulation scan and one additional scan during deep inspiration using ABC were performed. A comparison between planning treatment with clinical target volume including supraclavicular regions, mediastinum, andmore » hila was performed, both in free breathing and using ABC. Results: For a prescription of 36 Gy, pulmonary dose-volume histograms revealed a mean reduction in lung volume irradiated at more than 20 Gy (V20) and 30 Gy (V30) of 25% and 26%, respectively, using ABC (p = 0.016). The mean volume of heart irradiated at 30 Gy or more decreased from 15% to 12% (nonsignificant). The mean dose delivered to breasts in girls was small in both situations (less than 2 Gy) and stable with or without ABC. Considering axillary irradiation, the mean dose delivered to breasts remained low (<9 Gy), without significant difference using ABC or not. The mean radiation dose delivered to thyroid was stable using ABC or not. Conclusions: Using ABC is feasible in childhood. The use of ABC decreases normal lung tissue irradiation. Concerning heart irradiation, a minimal gain is also shown. No significant change has been demonstrated concerning breast and thyroid irradiation.« less

A comparison of heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major.

PubMed

Amoozgar, Hamid; Zeighami, Samaneh; Haghpanah, Sezaneh; Karimi, Mehran

2017-01-01

The goal of this study was to compare heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major. In this cross-sectional study, 60 patients with beta thalassemia major and 60 patients with beta thalassemia intermedia who had clinically no symptoms of arrhythmia and clinically normal heart function were evaluated using 24-hour ambulatory electrocardiogram monitoring and echocardiography. For data analysis SPSS ver.20 software was used. A P-value of less than 0.05 was considered statistically significant. The mean age of the beta thalassemia intermedia patients was 24.18 ± 7.9 years and the mean age in beta thalassemia major was 24.38 ± 7.7 years (P>0.05). Premature atrial contractions (PACs) were observed in 14 (23.3%) patients with beta thalassemia intermedia and in 22 (36.6%) beta thalassemia major patients. Premature ventricular contractions (PVCs) were detected in 8 (13.3%) patients in the beta thalassemia intermediate group and 16 (26.6) patients in the beta thalassemia major group, respectively. The left ventricular diastolic dimension, end-diastolic volume, and stroke volume were significantly higher in beta thalassemia intermedia group (P<0.05). Pulmonary acceleration time as an indicator of pulmonary pressure was lower in beta thalassemia intermedia group. Both atrial and ventricular arrhythmias were more common in the beta thalassemia major group. Higher end-diastolic volume and stroke volume were detected in the beta thalassemia intermedia group. Pulmonary acceleration time was lower in the beta thalassemia intermedia group, which can be an indicator of higher pulmonary pressure.

Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

PubMed

Scholten, Ralph R; Lotgering, Fred K; Hopman, Maria T; Van Dijk, Arie; Van de Vlugt, Maureen; Janssen, Mirian C H; Spaanderman, Marc E A

2015-11-01

Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; P<0.01). Initially normotensive formerly preeclamptic women have 17% chance to develop hypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive. © 2015 American Heart Association, Inc.

Comparison of adverse effects of proton and X-ray chemoradiotherapy for esophageal cancer using an adaptive dose-volume histogram analysis.

PubMed

Makishima, Hirokazu; Ishikawa, Hitoshi; Terunuma, Toshiyuki; Hashimoto, Takayuki; Yamanashi, Koichi; Sekiguchi, Takao; Mizumoto, Masashi; Okumura, Toshiyuki; Sakae, Takeji; Sakurai, Hideyuki

2015-05-01

Cardiopulmonary late toxicity is of concern in concurrent chemoradiotherapy (CCRT) for esophageal cancer. The aim of this study was to examine the benefit of proton beam therapy (PBT) using clinical data and adaptive dose-volume histogram (DVH) analysis. The subjects were 44 patients with esophageal cancer who underwent definitive CCRT using X-rays (n = 19) or protons (n = 25). Experimental recalculation using protons was performed for the patient actually treated with X-rays, and vice versa. Target coverage and dose constraints of normal tissues were conserved. Lung V5-V20, mean lung dose (MLD), and heart V30-V50 were compared for risk organ doses between experimental plans and actual treatment plans. Potential toxicity was estimated using protons in patients actually treated with X-rays, and vice versa. Pulmonary events of Grade ≥2 occurred in 8/44 cases (18%), and cardiac events were seen in 11 cases (25%). Risk organ doses in patients with events of Grade ≥2 were significantly higher than for those with events of Grade ≤1. Risk organ doses were lower in proton plans compared with X-ray plans. All patients suffering toxicity who were treated with X-rays (n = 13) had reduced predicted doses in lung and heart using protons, while doses in all patients treated with protons (n = 24) with toxicity of Grade ≤1 had worsened predicted toxicity with X-rays. Analysis of normal tissue complication probability showed a potential reduction in toxicity by using proton beams. Irradiation dose, volume and adverse effects on the heart and lung can be reduced using protons. Thus, PBT is a promising treatment modality for the management of esophageal cancer. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

New Insight from Using Spatiotemporal Image Correlation in Prenatal Screening of Fetal Conotruncal Defects

PubMed Central

Xie, Zuo-ping; Zhao, Bo-wen; Yuan, Hua; Hua, Qi-qi; Jin, She-hong; Shen, Xiao-yan; Han, Xin-hong; Zhou, Jia-mei; Fang, Min; Chen, Jin-hong

2013-01-01

Background: To establish the reference range of the angle between ascending aorta and main pulmonary artery of fetus in the second and third trimester using spatiotemporal image correlation (STIC), and to investigate the value of this angle in prenatal screening of conotruncal defects (CTDs). Materials and Methods: Volume images of 311 normal fetuses along with 20 fetuses with congenital heart diseases were recruited in this cross-sectional study. An offline analysis of acquired volume datasets was carried out with multiplanar mode. The angle between aorta and pulmonary artery was measured by navigating the pivot point and rotating axes and the reference range was established. The images of ascending aorta and main pulmonary artery in fetuses with congenital heart diseases were observed by rotating the axes within the normal angle reference range. Results: The angle between ascending aorta and main pulmonary artery of the normal fetus (range: 59.1˚~97.0˚, mean ± SD: 78.0˚ ± 9.7˚) was negatively correlated with gestational age (r = -0.52; p<0.01). By rotating the normal angle range corresponding to gestational age, the fetuses with CTD could not display views of their left ventricular long axis and main pulmonary trunk correctly. Conclusion: The left ventricular long axis and main pulmonary trunk views can be displayed using STIC so that the echocardiographic protocol of the cardiovascular joint could be standardized. The reference range of the angle between ascending aorta and main pulmonary artery is clinically useful in prenatal screening of CTD and provides a reliable quantitative standard to estimate the spatial relationship of the large arteries of fetus. PMID:24520485

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.

Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure.

PubMed

Soucy, Kevin G; Bartoli, Carlo R; Phillips, Dustin; Giridharan, Guruprasad A; Sobieski, Michael A; Wead, William B; Dowling, Robert D; Wu, Zhongjun J; Prabhu, Sumanth D; Slaughter, Mark S; Koenig, Steven C

2017-06-01

Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2-4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.

Hyperoxic preconditioning fails to confer additional protection against ischemia-reperfusion injury in acute diabetic rat heart.

PubMed

Pourkhalili, Khalil; Hajizadeh, Sohrab; Akbari, Zahra; Dehaj, Mansour Esmaili; Akbarzadeh, Samad; Alizadeh, Alimohammad

2012-01-01

Experimental studies show that detrimental effects of ischemia-reperfusion (I/R) injury can be attenuated by hyperoxic preconditioning in normal hearts, however, there are few studies about hyperoxia effects in diseased myocardium. The present study was designed to assess the cardioprotective effects of hyperoxia pretreatment (≥ 95 % O2) in acute diabetic rat hearts. Normal and one week acute diabetic rats were either exposed to 60 (H60) and 180 (H180) min of hyperoxia or exposed to normal atmospheric air (21 % O2). Then hearts were isolated immediately and subjected to 30 min of regional ischemia followed by 120 min of reperfusion. Infarct size, cardiomyocyte apoptosis, enzymes release and ischemia induced arrhythmias were determined. Heart of diabetic control rats had less infarct size and decreased LDH and CK-MB release compared to normal hearts. 60 and 180 min of hyperoxia reduced myocardial infarct size and enzymes release in normal hearts. 180 min of hyperoxia also decreased cardiomyocytes apoptosis in normal state. On the other hand, protective values of hyperoxia were not significantly different in diabetic hearts. Moreover, hyperoxia reduced severity of ventricular arrhythmias in normal rat hearts whereas; it did not confer any additional antiarrhythmic protection in diabetic hearts. These findings suggest that diabetic hearts are less susceptible to ischemia-induced arrhythmias and infarction. Hyperoxia greatly protects rat hearts against I/R injury in normal hearts, however, it could not provide added cardioprotective effects in acute phase of diabetes.

Long-term low dose dietary resveratrol supplement reduces cardiovascular structural and functional deterioration in chronic heart failure in rats.

PubMed

Ahmet, Ismayil; Tae, Hyun-Jin; Lakatta, Edward G; Talan, Mark

2017-03-01

A short-term exposure to resveratrol at high dosages exerts a remarkable cardioprotective effect. Whether a long-term exposure to resveratrol at low dosages that can be obtained through consumption of a resveratrol-rich diet is beneficial to heart diseases is unknown. We tested the effects of a resveratrol-enriched diet on cardiovascular remodeling of chronic heart failure (CHF) in rats resulting from permanent ligation of left coronary artery. Two weeks after surgery, rats were started on either a resveratrol-enriched (R; 5 mg/kg per day; n = 23) or normal (Control; n = 23) diet for next 10 months. Serial echocardiography in Control showed a significant decline in LV ejection fraction, increases in LV end-systolic and end-diastolic volumes, and expansion in myocardial infarct from pre-treatment values. In R, compared with Control, there were substantial improvements in those parameters. End-point LV pressure-volume loop analysis showed a significantly improved LV systolic function and AV-coupling, an index of energy transfer efficacy between the heart and aortic tree, in R compared with Control (p < 0.05). Aortic pulse wave velocity, a measure of arterial stiffness, was significantly lower in R (389 ± 15 cm/s; p < 0.05) compared with Control (489 ± 38 cm/s). These results demonstrated that long-term dietary resveratrol supplement reduces cardiovascular structural and functional deterioration in CHF.

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

Cardiovascular Adjustments to Gravitational Stress

NASA Technical Reports Server (NTRS)

Blomqvist, C. Gunnar; Stone, H. Lowell

1991-01-01

The effects of gravity on the cardiovascular system must be taken into account whenever a hemodynamic assessment is made. All intravascular pressure have a gravity-dependent hydrostatic component. The interaction between the gravitational field, the position of the body, and the functional characteristics of the blood vessels determines the distribution of intravascular volume. In turn this distribution largely determines cardiac pump function. Multiple control mechanisms are activated to preserve optimal tissue perfusion when the magnitude of the gravitational field or its direction relative to the body changes. Humans are particularly sensitive to such changes because of the combination of their normally erect posture and the large body mass and blood volume below the level of the heart. Current aerospace technology also exposes human subjects to extreme variations in the gravitational forces that range from zero during space travel to as much an nine-times normal during operation of high-performance military aircraft. This chapter therefore emphasizes human physiology.

Hemodynamics, renal function, plasma renin, and aldosterone in man after 5 to 14 days of bedrest

NASA Technical Reports Server (NTRS)

Melada, G. A.; Goldman, R. H.; Luetscher, J. A.; Zager, P. G.

1975-01-01

Continuous bedrest for 5 to 14 days had no significant effect on resting heart rate, blood pressure, or cardiac output in six normal men. Head-up tilt induced greater tachycardia in 5 of 6 patients after bed rest than in the control period. Propranolol diminished both tachycardia and the incidence of hypotension and faintness in upright posture. Plasma volume fell, extracellular fluid volume increased, and plasma renin activity was significantly elevated following bedrest. Unusually large increases in plasma renin followed head-up tilt or administration of isoproterenol during bedrest and after resuming normal activity. During bedrest, plasma aldosterone was often increased in the early morning. It is concluded that after bedrest, upright posture evokes strong beta-adrenergic activity as well as exaggerated metabolic and circulatory responses which can be reduced or abolished by the beta-adrenergic blocker, propranolol.

Experimental study on acute toxicity of Qingnao tablet to mice

NASA Astrophysics Data System (ADS)

Xie, Guoqi; Wang, Huamin; Ma, Zhenzhen; Hao, Shaojun; Li, Jun; Wang, Hongyu; Wen, Zhonghua; Zhang, Zhengchen

2018-04-01

To investigate the effect of Qingnao tablets on acute toxicity in mice. Forty mice, half male and half female, were randomly divided into normal saline group and Qingnao tablet group. After fasting for 12 hours, the mice were given 0. 4 ml / 10 g in maximum volume. In 1st, the rats were perfused 3 times (every 8 hours). The rats in the saline group were perfused with the same volume of saline in the same way. The mice were observed continuously within 3 hours and then every hour. The mice were given a normal diet for 14 consecutive days, and the changes of autonomous activity, reaction, diet, stool, secretion, eye and nose were observed daily. The mice fasted on the 13th day and weighed on the 14th day. And then put the mice to death, The changes of the liver, heart, spleen, lung, kidney, stomach, intestines, and brain were observed by the naked eye. There was no obvious abnormality in normal saline group. The autonomous activity of mice in the administration group decreased after initial administration, and gradually returned to normal after 2 hours of administration. On the day of administration, the stool of the mice became dark brown, and the feces returned to normal after 1.1 days of normal urination. No other mice had abnormal secretion, reaction, eye nose, diet, etc. On the 14th day, there were no visible heart, liver, spleen, lung, kidney, gastrointestinal tract in normal saline group and Qingnao tablet group. Abnormal changes in brain and other organs (edema, color, etc.). In the normal saline group and Qingnao tablet group, the initial weight of the mice was: 21.70 ± 0.97N 21.71 ± 1.13, and the weight of the mice on the 7th day was 29.70 ± 2.4c28.65 ± 3.11. On the 14th day, the body weight was 32.38 ± 3.40, 33.77 ± 3.82. Qingnao tablet has no obvious toxicity to the main organs of mice, so it can be considered safe in clinical use.

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.

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.

Modelling the heart with the atrioventricular plane as a piston unit.

PubMed

Maksuti, Elira; Bjällmark, Anna; Broomé, Michael

2015-01-01

Medical imaging and clinical studies have proven that the heart pumps by means of minor outer volume changes and back-and-forth longitudinal movements in the atrioventricular (AV) region. The magnitude of AV-plane displacement has also shown to be a reliable index for diagnosis of heart failure. Despite this, AV-plane displacement is usually omitted from cardiovascular modelling. We present a lumped-parameter cardiac model in which the heart is described as a displacement pump with the AV plane functioning as a piston unit (AV piston). This unit is constructed of different upper and lower areas analogous with the difference in the atrial and ventricular cross-sections. The model output reproduces normal physiology, with a left ventricular pressure in the range of 8-130 mmHg, an atrial pressure of approximatly 9 mmHg, and an arterial pressure change between 75 mmHg and 130 mmHg. In addition, the model reproduces the direction of the main systolic and diastolic movements of the AV piston with realistic velocity magnitude (∼10 cm/s). Moreover, changes in the simulated systolic ventricular-contraction force influence diastolic filling, emphasizing the coupling between cardiac systolic and diastolic functions. The agreement between the simulation and normal physiology highlights the importance of myocardial longitudinal movements and of atrioventricular interactions in cardiac pumping. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

Myoarchitecture and connective tissue in hearts with tricuspid atresia

PubMed Central

Sanchez-Quintana, D; Climent, V; Ho, S; Anderson, R

1999-01-01

Objective—To compare the atrial and ventricular myoarchitecture in the normal heart and the heart with tricuspid atresia, and to investigate changes in the three dimensional arrangement of collagen fibrils.
Methods—Blunt dissection and cell maceration with scanning electron microscopy were used to study the architecture of the atrial and ventricular musculature and the arrangement of collagen fibrils in three specimens with tricuspid atresia and six normal human hearts.
Results—There were significant modifications in the myoarchitecture of the right atrium and the left ventricle, both being noticeably hypertrophied. The middle layer of the ventricle in the abnormal hearts was thicker than in the normal hearts. The orientation of the superficial layer in the left ventricle in hearts with tricuspid atresia was irregular compared with the normal hearts. Scanning electron microscopy showed coarser endomysial sheaths and denser perimysial septa in hearts with tricuspid atresia than in normal hearts.
Conclusions—The overall architecture of the muscle fibres and its connective tissue matrix in hearts with tricuspid atresia differed from normal, probably reflecting modelling of the myocardium that is inherent to the malformation. This is in concordance with clinical observations showing deterioration in pump function of the dominant left ventricle from very early in life.

 Keywords: tricuspid atresia; congenital heart defects; connective tissue; fibrosis PMID:9922357

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

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

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

Obesity Alters Molecular and Functional Cardiac Responses to Ischemia-Reperfusion and Glucagon-Like Peptide-1 Receptor Agonism

PubMed Central

Sassoon, Daniel J; Goodwill, Adam G; Noblet, Jillian N; Conteh, Abass M; Herring, B. Paul; McClintick, Jeanette N; Tune, Johnathan D; Mather, Kieren J

2016-01-01

This study tested the hypothesis that obesity alters the cardiac response to ischemia/reperfusion and/or glucagon like peptide-1 (GLP-1) receptor activation, and that these differences are associated with alterations in the obese cardiac proteome and microRNA (miR) transcriptome. Ossabaw swine were fed normal chow or obesogenic diet for 6 months. Cardiac function was assessed at baseline, during a 30-min coronary occlusion, and during 2 hours of reperfusion in anesthetized swine treated with saline or exendin-4 for 24 hours. Cardiac biopsies were obtained from normal and ischemia/reperfusion territories. Fat-fed animals were heavier, and exhibited hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. Plasma troponin-I concentration (index of myocardial injury) was increased following ischemia/reperfusion and decreased by exendin-4 treatment in both groups. Ischemia/reperfusion produced reductions in systolic pressure and stroke volume in lean swine. These indices were higher in obese hearts at baseline and relatively maintained throughout ischemia/reperfusion. Exendin-4 administration increased systolic pressure in lean swine but did not affect blood pressure in obese swine. End-diastolic volume was reduced by exendin-4 following ischemia/reperfusion in obese swine. These divergent physiologic responses were associated with obesity-related differences in proteins related to myocardial structure/function (e.g. titin) and calcium handling (e.g. SERCA2a, histidine-rich Ca2+ binding protein). Alterations in expression of cardiac miRs in obese hearts included miR-15, miR-27, miR-130, miR-181, and let-7. Taken together, these observations validate this discovery approach and reveal novel associations that suggest previously undiscovered mechanisms contributing to the effects of obesity on the heart and contributing to the actions of GLP-1 following ischemia/reperfusion. PMID:27234258

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.

First third filling parameters of left ventricle assessed from gated equilibrium studies in patients with various heart diseases

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

Adatepe, M.H.; Nichols, K.; Powell, O.M.

1984-01-01

The authors determined the first third filling fraction (1/3 FF), the maximum filling rate (1/3 FR) and the mean filling rate (1/3 MFR) for the first third diastolic filling period of the left ventricle in patients with coronary artery disease (CAD), valvular heart disease (VHD), pericardial effusion (PE), cardiomyopathies (CM), chronic obstructive lung disease (COPD) and in 5 normals-all from resting gated equilibrium studies. Parameters are calculated from the third order Fourier fit to the LV volume curve and its derivative. 1/3 FF% = 1/3 diastolic count - end systolic count / 1/3 diastolic count x 100. Patients with CADmore » are divided into two groups: Group I with normal ejection fraction (EF) and wall motion (WM); Group II with abnormal EF and WM. Results are shown in the table. Abnormal filling parameters are found not only in CAD but in VHD, PE and CM. The authors conclude that the first third LV filling parameters are sensitive but non-specific indicators of filling abnormalities caused by diverse etiologic factors. Abnormal first third filling parameters may occur in the presence of a normal resting EF and WM in CAD.« less

Impact of age and sex on normal left heart structure and function.

PubMed

Hagström, Linn; Henein, Michael Y; Karp, Kjell; Waldenström, Anders; Lindqvist, Per

2017-11-01

Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose. We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions. Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years. Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

SU-F-T-498: A Comparative Evaluation of 6MV Flatten Beam and Flattening Filter Free Photon Beam in Carcinoma Breast

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

Tamilarasu, Suresh; Saminathan, Madeswaran

Purpose: Aim of the current study is to look plan quality, treatment beam ON time for IMRT using 6MV FB (Flatten Beam) and FFFB (Flattening Filter Free Beam) in left breast cancer cases. Methods: Ten left breast cancer patients treated with breast conserving surgical (BCS) procedure approach and adjuvant radiotherapy were selected from the department database. Simultaneous Integrated boost (SIB) technique was used to irradiate the total left breast (PTV) to a dose of 50.40Gy with concomitant enhance to the lumpectomy cavity known as gross tumour volume (GTV) to a dose of 59.40Gy in 28 fractions. Plans 6MV FB IMRTmore » and 6MV FFFB IMRT had been generated to achieve dose to 95% target volume (TV) and spare Organ at risks (OAR’s). Homogeneity index (HI), conformity index (CI), treatment monitor unit (MU),normal tissues integral dose (NTID) and low dose volume of normal tissue were compared. Results: There was no statistically huge difference among the plans with respect to target volume coverage, CI HI, Ipsilateral Lung and Breast. But statistically significant difference (p< 0.05) as observed in Heart, V5Gy of Contralateral Lung, MU’s NTID and low dose volume of normal tissue. Conclusion: 6MV FB and FFF beam produce almost equivalent plans in IMRT modality with admire to target volume coverage, HI, CI. Beam on time and NTID was determined to be much less in 6MV FFFB IMRT. FFF beam leads to a time saving treatment delivery and fewer NTID in cancer of left breast cases.« less

Cardiac muscle organization revealed in 3-D by imaging whole-mount mouse hearts using two-photon fluorescence and confocal microscopy.

PubMed

Sivaguru, Mayandi; Fried, Glenn; Sivaguru, Barghav S; Sivaguru, Vignesh A; Lu, Xiaochen; Choi, Kyung Hwa; Saif, M Taher A; Lin, Brian; Sadayappan, Sakthivel

2015-11-01

The ability to image the entire adult mouse heart at high resolution in 3-D would provide enormous advantages in the study of heart disease. However, a technique for imaging nuclear/cellular detail as well as the overall structure of the entire heart in 3-D with minimal effort is lacking. To solve this problem, we modified the benzyl alcohol:benzyl benzoate (BABB) clearing technique by labeling mouse hearts with periodic acid Schiff (PAS) stain. We then imaged the hearts with a combination of two-photon fluorescence microscopy and automated tile-scan imaging/stitching. Utilizing the differential spectral properties of PAS, we could identify muscle and nuclear compartments in the heart. We were also able to visualize the differences between a 3-month-old normal mouse heart and a mouse heart that had undergone heart failure due to the expression of cardiac myosin binding protein-C (cMyBP-C) gene mutation (t/t). Using 2-D and 3-D morphometric analysis, we found that the t/t heart had anomalous ventricular shape, volume, and wall thickness, as well as a disrupted sarcomere pattern. We further validated our approach using decellularized hearts that had been cultured with 3T3 fibroblasts, which were tracked using a nuclear label. We were able to detect the 3T3 cells inside the decellularized intact heart tissue, achieving nuclear/cellular resolution in 3-D. The combination of labeling, clearing, and two-photon microscopy together with tiling eliminates laborious and time-consuming physical sectioning, alignment, and 3-D reconstruction.

Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

PubMed

Maksuti, Elira; Westerhof, Nico; Westerhof, Berend E; Broomé, Michael; Stergiopulos, Nikos

2016-01-01

During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well. In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study. Parameters representing arterial changes (resistance and stiffness) during aging were based on literature values, whereas parameters representing cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). When taking into account arterial changes only, the systolic and diastolic pressure did not agree well with the population data. Between 20 and 80 years, systolic pressure increased from 100 to 122 mmHg, and diastolic pressure decreased from 76 to 55 mmHg. When taking cardiac adaptations into account as well, systolic and diastolic pressure increased from 100 to 151 mmHg and decreased from 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging. The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

Powering a leadless pacemaker using a PiezoMEMS energy harvester

NASA Astrophysics Data System (ADS)

Jackson, Nathan; Olszewski, Oskar; O'Murchu, Cian; Mathewson, Alan

2017-06-01

MEMS based vibrational energy harvesting devices have been a highly researched topic over the past decade. The application targeted in this paper focuses on a leadless pacemaker that will be implanted in the right ventricle of the heart. A leadless pacemaker requires the same functionality as a normal pacemaker, but with significantly reduced volume. The reduced volume limits the space for a battery; therefore an energy harvesting device is required. This paper compares varying the dimensions of a linear MEMS based piezoelectric energy harvester that can harvest energy from the mechanical vibrations of the heart due to shock induced vibration. Typical MEMS linear energy harvesting devices operate at high frequency (<50 Hz) with low acceleration (< 1g). The force generated from the heart acts as a series of impulses as opposed to traditional sinusoidal vibration force with high acceleration (1-4 g). Therefore the design of a MEMS harvester that is based on shock-induced vibration is necessary. PiezoMEMS energy harvesting devices consisting of a silicon substrate and mass with aluminium nitride piezoelectric material were developed and characterized using acceleration forces that mimic the heartbeat. Peak powers of up to 25μW were obtained at 1 g acceleration with a powder density of approximately 1.5 mW cm-3.

Left ventricular stiffness estimated by diastolic wall strain is associated with paroxysmal atrial fibrillation in structurally normal hearts.

PubMed

Uetake, Shunsuke; Maruyama, Mitsunori; Yamamoto, Teppei; Kato, Katsuhito; Miyauchi, Yasushi; Seino, Yoshihiko; Shimizu, Wataru

2016-12-01

Left ventricular (LV) diastolic dysfunction depends on an impaired relaxation and stiffness. Abnormal LV relaxation contributes to the development of atrial fibrillation (AF), but the role of LV stiffness in AF remains unclear. Diastolic wall strain (DWS), a load-independent, noninvasive direct measure of LV stiffness, correlates with prevalent AF. This study included 328 consecutive subjects with structurally normal hearts: 164 paroxysmal AF patients and 164 age- and sex-matched (1:1) controls. We calculated the DWS from the M-mode echocardiographic measurements of the LV posterior wall thickness at end-systole and end-diastole during sinus rhythm. The DWS was lower in the AF patients (0.35 ± 0.07) than in the controls (0.41 ± 0.06; P < 0.001). After adjusting for the risk factors of AF using a conditional logistic regression analysis, a history of hypertension, plasma brain-type natriuretic peptide level, and DWS were independently associated with AF prevalence, whereas body mass index, LV mass index, left atrial volume, and any conventional indices of the diastolic function were not. A low DWS (<0.380) was the strongest indicator of AF (odds ratio: 6.22, 95% confidence interval: 3.08-14.2, P < 0.001). Increased LV stiffness estimated by DWS was a strong determinant of the prevalence of AF. LV stiffness may play a role in the pathogenesis of paroxysmal AF in structurally normal hearts. © 2016 Wiley Periodicals, Inc.

Contribution of titin and extracellular matrix to passive pressure and measurement of sarcomere length in the mouse left ventricle

PubMed Central

Chung, Charles S; Granzier, Henk L

2011-01-01

It remains to be established to what degree titin and the extracellular matrix (ECM) contribute to passive pressure in the left ventricle (LV). Thus, we aimed to elucidate the contribution of major molecular determinants of passive pressure in the normal mouse LV. Furthermore, we determined the working sarcomere length (SL) range of the LV to bridge our findings to earlier work in skinned muscle fibers. We utilized Frank-Starling type protocols to obtain diastolic pressure-volume relationships (PVR) in Langendorff perfused isolated LVs. To quantify the molecular contribution of titin and ECM, we innovated on methods of fiber mechanics to chemically permeabilize intact LVs and measure a fully passive PVR. To differentially dissect the contributions of the ECM and titin, we utilized myofilament extraction techniques in permeabilized LVs, measuring passive PVRs at each stage in the protocol. Myofilament extraction suggests that titin contributes ~80% of passive pressures in the heart. Langendorff perfusion was also used to chemically fix passive and BaCl2 activated hearts at specific volumes to determine that the maximal working SL range of the midwall LV fibers is approximately 1.8-2.2 μm. A model of the passive SL-Volume relationship was then used to estimate the pressure-SL relationships, indicating that the ECM contribution does not exceed titin's contribution until large volumes with SLs>~2.2μm. In conclusion, within physiological volumes titin is the dominant contributor to LV passive pressure, and ECM-based pressures dominates at larger volumes. PMID:21255582

Reduced Gray Matter Volume Is Associated With Poorer Instrumental Activities of Daily Living Performance in Heart Failure.

PubMed

Alosco, Michael L; Brickman, Adam M; Spitznagel, Mary Beth; Narkhede, Atul; Griffith, Erica Y; Cohen, Ronald; Sweet, Lawrence H; Josephson, Richard; Hughes, Joel; Gunstad, John

2016-01-01

Heart failure patients require assistance with instrumental activities of daily living in part because of the high rates of cognitive impairment in this population. Structural brain insult (eg, reduced gray matter volume) is theorized to underlie cognitive dysfunction in heart failure, although no study has examined the association among gray matter, cognition, and instrumental activities of daily living in heart failure. The aim of this study was to investigate the associations among gray matter volume, cognitive function, and functional ability in heart failure. A total of 81 heart failure patients completed a cognitive test battery and the Lawton-Brody self-report questionnaire to assess instrumental activities of daily living. Participants underwent magnetic resonance imaging to quantify total gray matter and subcortical gray matter volume. Impairments in instrumental activities of daily living were common in this sample of HF patients. Regression analyses controlling for demographic and medical confounders showed that smaller total gray matter volume predicted decreased scores on the instrumental activities of daily living composite, with specific associations noted for medication management and independence in driving. Interaction analyses showed that reduced total gray matter volume interacted with worse attention/executive function and memory to negatively impact instrumental activities of daily living. Smaller gray matter volume is associated with greater impairment in instrumental activities of daily living in persons with heart failure, possibly via cognitive dysfunction. Prospective studies are needed to clarify the utility of clinical correlates of gray matter volume (eg, cognitive dysfunction) in identifying heart failure patients at risk for functional decline and determine whether interventions that target improved brain and cognitive function can preserve functional independence in this high-risk population.

Arrhythmias (For Parents)

MedlinePlus

... or a heart function test. What's a Normal Heart Rate? Heart rate is measured by counting the number of beats per minute. Someone's normal heart rate depends on things like the person's age and ...

Tachycardia

MedlinePlus

... normal while at rest. It's normal for your heart rate to rise during exercise or as a physiological ... the heart or both while at rest. Your heart rate is controlled by electrical signals sent across heart ...

Cardiac chamber volumes by echocardiography using a new mathematical method: A promising technique for zero-G use

NASA Technical Reports Server (NTRS)

Buckey, J. C.; Beattie, J. M.; Gaffney, F. A.; Nixon, J. V.; Blomqvist, C. G.

1984-01-01

Accurate, reproducible, and non-invasive means for ventricular volume determination are needed for evaluating cardiovascular function zero-gravity. Current echocardiographic methods, particularly for the right ventricle, suffer from a large standard error. A new mathematical approach, recently described by Watanabe et al., was tested on 1 normal formalin-fixed human hearts suspended in a mineral oil bath. Volumes are estimated from multiple two-dimensional echocardiographic views recorded from a single point at sequential angles. The product of sectional cavity area and center of mass for each view summed over the range of angles (using a trapezoidal rule) gives volume. Multiple (8-14) short axis right ventricle and left ventricle views at 5.0 deg intervals were videotaped. The images were digitized by two independent observers (leading-edge to leading-edge technique) and analyzed using a graphics tablet and microcomputer. Actual volumes were determined by filling the chambers with water. These data were compared to the mean of the two echo measurements.

Exploring Heart and Lung Function in Space: ARMS Experiments

NASA Technical Reports Server (NTRS)

Kuipers, Andre; Cork, Michael; LeGouic, Marine

2002-01-01

The Advanced Respiratory Monitoring System (ARMS) is a suite of monitoring instruments and supplies used to study the heart, lungs, and metabolism. Many experiments sponsored by the European Space Agency (ESA) will be conducted using ARMS during STS-107. The near-weightless environment of space causes the body to undergo many physiological adaptations, and the regulation of blood pressure is no exception. Astronauts also experience a decrease in blood volume as an adaptation to microgravity. Reduced blood volume may not provide enough blood pressure to the head during entry or landing. As a result, astronauts often experience light-headedness, and sometimes even fainting, when they stand shortly after returning to Earth. To help regulate blood pressure and heart rate, baroreceptors, sensors located in artery walls in the neck and near the heart, control blood pressure by sending information to the brain and ensuring blood flow to organs. These mechanisms work properly in Earth's gravity but must adapt in the microgravity environment of space. However, upon return to Earth during entry and landing, the cardiovascular system must readjust itself to gravity, which can cause fluctuation in the control of blood pressure and heart rate. Although the system recovers in hours or days, these occurrences are not easily predicted or understood - a puzzle investigators will study with the ARMS equipment. In space, researchers can focus on aspects of the cardiovascular system normally masked by gravity. The STS-107 experiments using ARMS will provide data on how the heart and lungs function in space, as well as how the nervous system controls them. Exercise will also be combined with breath holding and straining (the Valsalva maneuver) to test how heart rate and blood pressure react to different stresses. This understanding will improve astronauts' cardiopulmonary function after return to Earth, and may well help Earthbound patients who experience similar effects after long-term bed rest.

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.

Dosimetric advantages of generalised equivalent uniform dose-based optimisation on dose–volume objectives in intensity-modulated radiotherapy planning for bilateral breast cancer

PubMed Central

Lee, T-F; Ting, H-M; Chao, P-J; Wang, H-Y; Shieh, C-S; Horng, M-F; Wu, J-M; Yeh, S-A; Cho, M-Y; Huang, E-Y; Huang, Y-J; Chen, H-C; Fang, F-M

2012-01-01

Objective We compared and evaluated the differences between two models for treating bilateral breast cancer (BBC): (i) dose–volume-based intensity-modulated radiation treatment (DV plan), and (ii) dose–volume-based intensity-modulated radiotherapy with generalised equivalent uniform dose-based optimisation (DV-gEUD plan). Methods The quality and performance of the DV plan and DV-gEUD plan using the Pinnacle3® system (Philips, Fitchburg, WI) were evaluated and compared in 10 patients with stage T2–T4 BBC. The plans were delivered on a Varian 21EX linear accelerator (Varian Medical Systems, Milpitas, CA) equipped with a Millennium 120 leaf multileaf collimator (Varian Medical Systems). The parameters analysed included the conformity index, homogeneity index, tumour control probability of the planning target volume (PTV), the volumes V20 Gy and V30 Gy of the organs at risk (OAR, including the heart and lungs), mean dose and the normal tissue complication probability. Results Both plans met the requirements for the coverage of PTV with similar conformity and homogeneity indices. However, the DV-gEUD plan had the advantage of dose sparing for OAR: the mean doses of the heart and lungs, lung V20 Gy, and heart V30 Gy in the DV-gEUD plan were lower than those in the DV plan (p<0.05). Conclusions A better result can be obtained by starting with a DV-generated plan and then improving it by adding gEUD-based improvements to reduce the number of iterations and to improve the optimum dose distribution. Advances to knowledge The DV-gEUD plan provided superior dosimetric results for treating BBC in terms of PTV coverage and OAR sparing than the DV plan, without sacrificing the homogeneity of dose distribution in the PTV. PMID:23091290

Design of a hydraulic analog of the circulatory system for evaluating artificial hearts.

PubMed

Donovan, F M

1975-01-01

A major problem in improving artificial heart designs is the absence of methods for accurate in vitro testing of artificial heart systems. A mock circulatory system has been constructed which hydraulically simulates the systemic and pulmonary circulations of the normal human. The device is constructed of 1/2 in. acrylic sheet and has overall dimensions of 24 in. wide, 16 in. tall, and 8 in. deep. The artificial heart to be tested is attached to the front of the device, and pumps fluid from the systemic venous chamber into the pulmonary arterial chamber and from the pulmonary venous chamber into the systemic arterial chamber. Each of the four chambers is hermetically sealed. The compliance of each chamber is determined by the volume of air trapped above the fluid in that chamber. The pulmonary and systemic resistances are set automatically by bellows-operated valves to simulate the barroreceptor response in the systemic arteries and the passive pulmonary resistance response in the pulmonary arteries. Cardiac output is measured by a turbine flowmeter in the systemic circulation. Results using the Kwan-Gett artificial heart show a good comparison between the mock circulatory system response and the calf response.

Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury.

PubMed

Srimachai, Sirintorn; Devaux, Sylvie; Demougeot, Celine; Kumphune, Sarawut; Ullrich, Nina D; Niggli, Ernst; Ingkaninan, Kornkanok; Kamkaew, Natakorn; Scholfield, C Norman; Tapechum, Sompol; Chootip, Krongkarn

2017-02-20

This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points. In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 μg/ml B. monnieri ethanolic extract (30 min), or (ii) with normal solution or extract for 10 min preceding no-perfusion ischemia (30 min) followed by reperfusion (30 min) with normal solution. Infarct volumes were measured by triphenyltetrazolium staining. L-type Ca 2+ -currents (I Ca, L ) were measured by whole-cell patching in HL-1 cells, a mouse atrial cardiomyocyte cell line. Cytotoxicity of B. monnieri was assessed in rat isolated ventricular myocytes by trypan blue exclusion. In normally perfused hearts, B. monnieri increased coronary flow by 63 ± 13% (30 μg/ml) and 216 ± 21% (100 μg/ml), compared to control (5 ± 3%) (n = 8-10, p < 0.001). B. monnieri treatment preceding ischemia/reperfusion improved left ventricular developed pressure by 84 ± 10% (30 μg/ml), 82 ± 10% (100 μg/ml) and 52 ± 6% (control) compared to pre- ischemia/reperfusion. Similarly, functional recovery showed a sustained increase. Moreover, B. monnieri (100 μg/ml) reduced the percentage of infarct size from 51 ± 2% (control) to 25 ± 2% (n = 6-8, p < 0.0001). B. monnieri (100 μg/ml) reduced I Ca, L by 63 ± 4% in HL-1 cells. Ventricular myocyte survival decreased at higher concentrations (50-1000 μg/ml) B. monnieri. B. monnieri improves myocardial function following ischemia/reperfusion injury through recovery of coronary blood flow, contractile force and decrease in infarct size. Thus this may lead to a novel cardioprotectant strategy.

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.

Comparison of frequencies of left ventricular systolic and diastolic heart failure in Chinese living in Hong Kong.

PubMed

Yip, G W; Ho, P P; Woo, K S; Sanderson, J E

1999-09-01

There is a wide variation (13% to 74%) in the reported prevalence of heart failure associated with normal left ventricular (LV) systolic function (diastolic heart failure). There is no published information on this condition in China. To ascertain the prevalence of diastolic heart failure in this community, 200 consecutive patients with the typical features of congestive heart failure were studied with standard 2-dimensional Doppler echocardiography. A LV ejection fraction (LVEF) >45% was considered normal. The results showed that 12.5% had significant valvular heart disease. Of the remaining 175 patients, 132 had a LVEF >45% (75%). Therefore, 66% of patients with a clinical diagnosis of heart failure had a normal LVEF. Heart failure with normal LV systolic function was more common than systolic heart failure in those >70 years old (65% vs 47%; p = 0.015). Most (57%) had an abnormal relaxation pattern in diastole and 14% had a restrictive filling pattern. In the systolic heart failure group, a restrictive filling pattern was more common (46%). There were no significant differences in the sex distribution, etiology, or prevalence of LV hypertrophy between these 2 heart failure groups. In conclusion, heart failure with a normal LVEF or diastolic heart failure is more common than systolic heart failure in Chinese patients with the symptoms of heart failure. This may be related to older age at presentation and the high prevalence of hypertension in this community.

Prenatal diagnosis of left isomerism with normal heart: a case report

PubMed Central

De Paola, Nico; Ermito, Santina; Nahom, Antonella; Dinatale, Angela; Pappalardo, Elisa Maria; Carrara, Sabina; Cavaliere, Alessandro; Brizzi, Cristiana

2009-01-01

Objective: Left isomerism, also called polysplenia, is a laterality disturbance associated with with paired leftsidedness viscera and multiple small spleens. Left isomerism, heart congenital abnormalities and gastrointestinal malformation are strongly associated. Methods: We present a case of prenatal diagnosis of left isomerism in a fetus with a structurally normal heart. Conclusion: Left isomerism syndrone may coesist with a structurally normal heart. If prenatal left isomerism is suspected, even in presence of a normal heart, is mandatory to esclude sign of gastrointestinal abnormalities, as late poly hy dramnios, and cardiac rhytm disturbance during the pregnancy and neonatal age. PMID:22439041

Vascular capacitance and cardiac output in pacing-induced canine models of acute and chronic heart failure.

PubMed

Ogilvie, R I; Zborowska-Sluis, D

1995-11-01

The relationship between stressed and total blood volume, total vascular capacitance, central blood volume, cardiac output (CO), and pulmonary capillary wedge pressure (Ppcw) was investigated in pacing-induced acute and chronic heart failure. Acute heart failure was induced in anesthetized splenectomized dogs by a volume load (20 mL/kg over 10 min) during rapid right ventricular pacing at 250 beats/min (RRVP) for 60 min. Chronic heart failure was induced by continuous RRVP for 2-6 weeks (average 24 +/- 2 days). Total vascular compliance and capacitance were calculated from the mean circulatory filling pressure (Pmcf) during transient circulatory arrest after acetylcholine at three different circulating volumes. Stressed blood volume was calculated as a product of compliance and Pmcf, with the total blood volume measured by a dye dilution. Central blood volume (CBV) and CO were measured by thermodilution. Central (heart and lung) vascular capacitance was estimated from the plot of Ppcw against CBV. Acute volume loading without RRVP increased capacitance and CO, whereas after volume loading with RRVP, capacitance and CO were unaltered from baseline. Chronic RRVP reduced capacitance and CO. All interventions, volume +/- RRVP or chronic RRVP, increased stressed and central blood volumes and Ppcw. Acute or chronic RRVP reduced central vascular capacitance. Cardiac output was increased when stressed and unstressed blood volumes increased proportionately as during volume loading alone. When CO was reduced and Ppcw increased, as during chronic RRVP or acute RRVP plus a volume load, stressed blood volume was increased and unstressed blood volume was decreased. Thus, interventions that reduced CO and increased Ppcw also increased stressed and reduced unstressed blood volume and total vascular capacitance.

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

Cardiac volumetry in patients with heart failure and reduced ejection fraction: a comparative study correlating multi-slice computed tomography and magnetic resonance tomography. Reasons for intermodal disagreement.

PubMed

Schroeder, Janina; Peterschroeder, Andreas; Vaske, Bernhard; Butz, Thomas; Barth, Peter; Oldenburg, Olaf; Bitter, Thomas; Burchert, Wolfgang; Horstkotte, Dieter; Langer, Christoph

2009-11-01

In humans with normal hearts multi-slice computed tomography (MSCT) based volumetry was shown to correlate well with the gold standard, cardiac magnetic resonance imaging (CMR). We correlated both techniques in patients with various degrees of heart failure and reduced ejection fraction (HFREF) resulting from cardiac dilatation. Twenty-four patients with a left ventricular enddiastolic volume (LV-EDV) of C 150 ml measured by angiography underwent MSCT and CMR scanning for left and right ventricular (LV, RV) volumetry. MSCT based short cardiac axis views were obtained beginning at the cardiac base advancing to the apex. These were reconstructed in 20 different time windows of the RR-interval (0-95%) serving for identification of enddiastole (ED) and end-systole (ES) and for planimetry. ED and ES volumes and the ejection fraction (EF) were calculated for LV and RV. MSCT based volumetry was compared with CMR. MSCT based LV volumetry significantly correlates with CMR as follows: LV-EDV r = 0.94, LV-ESV r = 0.98 and LV-EF r = 0.93, but significantly overestimates LV-EDV and LV-ESV and underestimates EF (P \\ 0.0001). MSCT based RV volumetry significantly correlates with CMR as follows: RV-EDV r = 0.79, RVESV r = 0.78 and RV-EF r = 0.73, but again significantly overestimates RV-EDV and RV-ESV and underestimates RV-EF (P \\ 0.0001). When compared with CMR a continuous overestimation of volumes and underestimation of EF needs to be considered when applying MSCT in HFREF patients.

The non-specificity of the left/right ventricular amplitude ratio (LV/RV) for mitral insufficiency

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

Preston, D.F.; Reinsel, M.S.; Martin, N.L.

1984-01-01

The purpose of this study was to determine the specificity of the LV/RV for mitral insufficiency. One hundred and sixty patients underwent MUGA studies as part of their diagnostic evaluation. Phase analysis was performed. In the amplitude image, the LV/RV was measured. Patients were divided into 11 clinical groups based on chart review after adequate follow-up. The groups were compared by Duncan's Multiple Comparsion Test. Patients with mitral insufficiency (N = 12, mean LV/RV = 2.36), those with idiopathic myocardiopathy (8, 2.29) and those with normal hearts having lung disease on chest x-ray (22, 1.78) formed a group which atmore » the p < .05 level were not different from one another. Patients with idiopathic myocardiography, normal hearts with lung disease on chest x-ray, normal hearts with lung disease (23, 1.71) formed a second group which partially overlapped with both the first and third groups. The third group consisted of normal hearts with lung disease, normal hearts not taking adriamycin (18, 1.53), normal hearts taking adriamycin (22, 1.50), congestive heart failure (19, 1.50), arteriosclerotic heart disease, normal hearts (15, 1.29), chronic obstructive pulmonary disease and acute myocardial infarction. The LV/RV is not specific for mitral insufficiency. Idiopathic myocardiography, and normal hearts with lung disease on chest x-ray (metastases, cancer of the lung, infiltrates, fibrosis, and/or COPD) cannot be differentiated on a statistical basis. The mitral insufficiency group had the greatest values of LV/RV. It appears that decreased RV amplitude seen with diseases causing strain on the right ventricle will result in elevated LV/RV ratios.« 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.

Role of neuropeptide Y in renal sympathetic vasoconstriction: studies in normal and congestive heart failure rats.

PubMed

DiBona, G F; Sawin, L L

2001-08-01

Sympathetic nerve activity, including that in the kidney, is increased in heart failure with increased plasma concentrations of norepinephrine and the vasoconstrictor cotransmitter neuropeptide Y (NPY). We examined the contribution of NPY to sympathetically mediated alterations in kidney function in normal and heart failure rats. Heart failure rats were created by left coronary ligation and myocardial infarction. In anesthetized normal rats, the NPY Y(1) receptor antagonist, H 409/22, at two doses, had no effect on heart rate, arterial pressure, or renal hemodynamic and excretory function. In conscious severe heart failure rats, high-dose H 409/22 decreased mean arterial pressure by 8 +/- 2 mm Hg but had no effect in normal and mild heart failure rats. During graded frequency renal sympathetic nerve stimulation (0 to 10 Hz), high-dose H 409/22 attenuated the decreases in renal blood flow only at 10 Hz (-36% +/- 5%, P <.05) in normal rats but did so at both 4 (-29% +/- 4%, P <.05) and 10 Hz (-33% +/- 5%, P <.05) in heart failure rats. The glomerular filtration rate, urinary flow rate, and sodium excretion responses to renal sympathetic nerve stimulation were not affected by high-dose H 409/22 in either normal or heart failure rats. NPY does not participate in the regulation of kidney function and arterial pressure in normal conscious or anesthetized rats. When sympathetic nervous system activity is increased, as in heart failure and intense renal sympathetic nerve stimulation, respectively, a small contribution of NPY to maintenance of arterial pressure and to sympathetic renal vasoconstrictor responses may be identified.

Unilateral lung transplantation for pulmonary fibrosis.

PubMed

1986-05-01

Improvements in immunosuppression and surgical techniques have made unilateral lung transplantation feasible in selected patients with end-stage interstitial lung disease. We report two cases of successful unilateral lung transplantation for end-stage respiratory failure due to pulmonary fibrosis. The patients, both oxygen-dependent, had progressive disease refractory to all treatment, with an anticipated life expectancy of less than one year on the basis of the rate of progression of the disease. Both patients were discharged six weeks after transplantation and returned to normal life. They are alive and well at 26 months and 14 months after the procedure. Pulmonary-function studies have shown substantial improvement in their lung volumes and diffusing capacities. For both patients, arterial oxygen tension is now normal and there is no arterial oxygen desaturation with exercise. This experience shows that unilateral lung transplantation, for selected patients with end-stage interstitial lung disease, provides a good functional result. Moreover, it avoids the necessity for cardiac transplantation, as required by the combined heart-lung procedure, and permits the use of the donor heart for another recipient.

Respiratory sinus arrhythmia is a limited measure of cardiac parasympathetic control in man.

PubMed Central

Kollai, M; Mizsei, G

1990-01-01

1. Respiratory modulation of cardiac parasympathetic activity and the relationship between respiratory sinus arrhythmia and parasympathetic control has been studied in twenty-nine conscious, healthy young adult subjects. 2. Changes in heart period in propranolol-treated subjects were taken as the measure of changes in cardiac parasympathetic activity; respiratory sinus arrhythmia was quantified as the difference between maximum and minimum heart periods in a given respiratory cycle; cardiac parasympathetic control was defined as the change in heart period after administration of a full dose of atropine. 3. During normal quiet breathing the inspiratory level of cardiac parasympathetic activity was not reduced to zero. The expiratory level was influenced by excitatory inputs whose activation was related to respiratory cycle length. 4. Slow breathing was associated with augmented sinus arrhythmia, but in different individuals the influence on minimum and maximum heart periods varied so that mean heart period was increased in some subjects but decreased in others. This occurred both in control conditions and after administration of a full dose of propranolol. 5. During normal breathing the correlation across subjects between respiratory sinus arrhythmia and parasympathetic control, although significant, was not close (r = 0.61). The relationship was not affected by beta-adrenergic blockade (r = 0.63). The strength of the correlation improved when multiple regression of respiratory sinus arrhythmia was performed on three variables: parasympathetic control, respiratory cycle length and tidal volume (R = 0.93). 6. It is concluded that in conscious human subjects the respiratory modulation of cardiac parasympathetic activity is different from that observed in the anaesthetized dog, and that variations in the amplitude of respiratory sinus arrhythmia do not necessarily reflect proportional changes in cardiac parasympathetic control. PMID:2391653

Neural Control of the Cardiovascular System in Space

NASA Technical Reports Server (NTRS)

Levine, Benjamin D.; Pawelczyk, James A.; Zuckerman, Julie; Zhang, Rong; Fu, Qi; Iwasaki, Kenichi; Ray, Chet; Blomqvist, C. Gunnar; Lane, Lynda D.; Giller, Cole A.

2003-01-01

During the acute transition from lying supine to standing upright, a large volume of blood suddenly moves from the chest into the legs. To prevent fainting, the blood pressure control system senses this change immediately, and rapidly adjusts flow (by increasing heart rate) and resistance to flow (by constricting the blood vessels) to restore blood pressure and maintain brain blood flow. If this system is inadequate, the brain has a backup plan. Blood vessels in the brain can adjust their diameter to keep blood flow constant. If blood pressure drops, the brain blood vessels dilate; if blood pressure increases, the brain blood vessels constrict. This process, which is called autoregulation, allows the brain to maintain a steady stream of oxygen, even when blood pressure changes. We examined what changes in the blood pressure control system or cerebral autoregulation contribute to the blood pressure control problems seen after spaceflight. We asked: (1) does the adaptation to spaceflight cause an adaptation in the blood pressure control system that impairs the ability of the system to constrict blood vessels on return to Earth?; (2) if such a defect exists, could we pinpoint the neural pathways involved?; and (3) does cerebral autoregulation become abnormal during spaceflight, impairing the body s ability to maintain constant brain blood flow when standing upright on Earth? We stressed the blood pressure control system using lower body negative pressure, upright tilt, handgrip exercise, and cold stimulation of the hand. Standard cardiovascular parameters were measured along with sympathetic nerve activity (the nerve activity causing blood vessels to constrict) and brain blood flow. We confirmed that the primary cardiovascular effect of spaceflight was a postflight reduction in upright stroke volume (the amount of blood the heart pumps per beat). Heart rate increased appropriately for the reduction in stroke volume, thereby showing that changes in heart rate regulation alone cannot be responsible for orthostatic hypotension after spaceflight. All of the astronauts in our study had an increase in sympathetic nerve activity during upright tilting on Earth postflight. This increase was well calibrated for the reduction in stroke volume induced by the upright posture. The results obtained from stimulating the sympathetic nervous system using handgrip exercise or cold stress were also entirely normal during and after spaceflight. No astronaut had reduced cerebral blood flow during upright tilt, and cerebral autoregulation was normal or even enhanced inflight. These experiments show that the cardiovascular adaptation to spaceflight does not lead to a defect in the regulation of blood vessel constriction via sympathetic nerve activity. In addition, cerebral autoregulation is well-maintained. It is possible that despite the increased sympathetic nerve activity, blood vessels did not respond with a greater degree of constriction than occurred preflight, possibly uncovering a limit of vasoconstrictor reserve.

Electrocardiogram

MedlinePlus

... history of heart disease in the family Normal Results Normal test results include: Heart rate: 60 to ... minute Heart rhythm: Consistent and even What Abnormal Results Mean Abnormal ECG results may be a sign ...

Restricted Field IMRT Dramatically Enhances IMRT Planning for Mesothelioma

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

Allen, Aaron M.; Schofield, Deborah; Hacker, Fred

2007-12-01

Purpose: To improve the target coverage and normal tissue sparing of intensity-modulated radiotherapy (IMRT) for mesothelioma after extrapleural pneumonectomy. Methods and Materials: Thirteen plans from patients previously treated with IMRT for mesothelioma were replanned using a restricted field technique. This technique was novel in two ways. It limited the entrance beams to 200{sup o} around the target and three to four beams per case had their field apertures restricted down to the level of the heart or liver to further limit the contralateral lung dose. New constraints were added that included a mean lung dose of <9.5 Gy and volumemore » receiving {>=}5 Gy of <55%. Results: In all cases, the planning target volume coverage was excellent, with an average of 97% coverage of the planning target volume by the target dose. No change was seen in the target coverage with the new technique. The heart, kidneys, and esophagus were all kept under tolerance in all cases. The average mean lung dose, volume receiving {>=}20 Gy, and volume receiving {>=}5 Gy with the new technique was 6.6 Gy, 3.0%, and 50.8%, respectively, compared with 13.8 Gy, 15%, and 90% with the previous technique (p < 0.0001 for all three comparisons). The maximal value for any case in the cohort was 8.0 Gy, 7.3%, and 57.5% for the mean lung dose, volume receiving {>=}20 Gy, and volume receiving {>=}5 Gy, respectively. Conclusion: Restricted field IMRT provides an improved method to deliver IMRT to a complex target after extrapleural pneumonectomy. An upcoming Phase I trial will provide validation of these results.« less

Cold pressor stimulus temperature and resting masseter muscle haemodynamics in normal humans.

PubMed

Maekawa, K; Kuboki, T; Clark, G T; Shinoda, M; Yamashita, A

1998-11-01

Cold pressor stimulation reportedly increases sympathetic nerve activity in human skeletal muscles. This study examined the effect of cold pressor stimulation on the resting haemodynamics of the right masseter muscle in normal individuals, using near-infrared spectroscopy. Nine healthy non-smoking males with no history of chronic muscle pain or vascular headaches participated. Their right hand was immersed in a water bath (4, 10, 15 degrees C) for exactly 1 min. Each trial lasted 7 min (1 min before, 1 min during, 5 min after stimulation) and a strictly random order was utilized for the three test temperatures and the mock trial. Masseter muscle haemoglobin concentration and oxygen saturation, as well as heart rate and blood pressure, were continuously recorded in each trial. After completing the four trials, each participant produced and sustained a 30-s maximum voluntary clench in the intercuspal position. Data across the four trials were baseline-corrected and then magnitude-normalized to the individual's highest absolute haemoglobin and oxygen signal during the 30-s maximal clenching effort. Haemoglobin and oxygen saturation increased progressively during cold pressor stimulation as the water temperature decreased (Hb, p < 0.0001; O2, p = 0.0327); very little effect was seen during the mock trial. Heart rate and blood pressure also increased progressively during the stimulation as the temperature decreased (heart rate, p = 0.0013; systolic blood pressure, p = 0.0042; diastolic blood pressure, p = 0.0156). These data suggest that cold pressor, stimulation induces a strong increase in intramuscular blood volume which appears to be due to both a local vasodilative response and increased cardiac output.

New Mathematical Model for the Surface Area of the Left Ventricle by the Truncated Prolate Spheroid

PubMed Central

Vale, Marcos de Paula; Martinez, Carlos Barreira

2017-01-01

The main aim of this study was the formula application of the superficial area of a truncated prolate spheroid (TPS) in Cartesian coordinates in obtaining a cardiac parameter that is not so much discussed in literature, related to the left ventricle (LV) surface area of the human heart, by age and sex. First we obtain a formula for the area of a TPS. Then a simple mathematical model of association of the axes measures of a TPS with the axes of the LV is built. Finally real values of the average dimensions of the humans LV are used to measure surface areas approximations of this heart chamber. As a result, the average superficial area of LV for normal patients is obtained and it is observed that the percentage differences of areas between men and women and their consecutive age groups are constant. A strong linear correlation between the obtained areas and the ventricular volumes normalized by the body areas was observed. The obtained results indicate that the superficial area of the LV, besides enabling a greater knowledge of the geometrical characteristics of the human LV, may be used as one of the normality cardiac verification criteria and be useful for medical and biological applications. PMID:28547001

A semi-automatic method for left ventricle volume estimate: an in vivo validation study

NASA Technical Reports Server (NTRS)

Corsi, C.; Lamberti, C.; Sarti, A.; Saracino, G.; Shiota, T.; Thomas, J. D.

2001-01-01

This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.

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

Liu, R; Liu, T; Qi, S

Purposes: There has been growing interest in treating breast cancer using VMAT technique. Our goal is to compare the dosimetry and treatment delivery parameters for the left-sided breast cancer treatment using various VMAT platforms from commercially available planning systems. Methods: Five consecutive left-sided breast cancer patients initially treated with conventional 3D-conformal radiotherapy (3DCRT) were selected. Four VMAT plans using most popular treatment planning systems, including Eclipse (Version 11, Varian), Pinnacle (Version 9.8, Philips), Monaco (Version 2.03, Elekta) and helical Tomotherapy (V4.0, Accuray). The same structure set and same planning goals were used for all VMAT plans. The dosimetric parameters includingmore » target coverage and minimum/maximum/mean, dose-volume endpoints for the selected normal structures: the heart, ipsilateral-/contralateral lung and breast, were evaluated. Other dosimetric indices including heterogeneity index (HI) were evaluated. The treatment delivery parameters, such as monitor unit (MUs) and delivery time were also compared. Results: VMAT increases dose homogeneity to the treated volume and reduces the irradiated heart and left-lung volumes. Compared to the 3DCRT technique, all VMAT plans offer better heart and left-lung dose sparing; the mean heart doses were 4.5±1.6(Monaco), 1.2±0.4(Pinnacle), 1.3± (Eclipse) and 5.6±4.4(Tomo), the mean left-lung doses were 5.9±1.5(Monaco), 3.7±0.7(Pinnacle), 1.4± (Eclipse) and 5.2±1.6 (Tomo), while for the 3DCRT plan, the mean heart and left-Lung doses were 2.9±2.0, and 6.8±4.4 (Gy) respectively. The averaged contralateral-breast and lung mean doses were higher in VMAT plans than the 3DCRT plans but were not statistically significant. Among all the VMAT plans, the Pinnacle plans often yield the lowest right-lung/breast mean doses, and slightly better heterogeneity indices that are similar to Tomotherapy plans. Treatment delivery time of the VMAT plans (except helical Tomotherapy IMRT) is estimated to be comparable with the conventional 3DCRT. Conclusion: VMAT achieves equal or better PTV coverage and comparable OARs sparing compared to the conventional 3DCRT techniques.« less

Alterations in Skeletal Muscle Indicators of Mitochondrial Structure and Biogenesis in Patients with Type 2 Diabetes and Heart Failure: Effects of Epicatechin Rich Cocoa

PubMed Central

Taub, Pam R.; Ramirez‐Sanchez, Israel; Ciaraldi, Theodore P.; Perkins, Guy; Murphy, Anne N.; Naviaux, Robert; Hogan, Michael; Maisel, Alan S.; Henry, Robert R.; Ceballos, Guillermo

2012-01-01

Abstract (‐)‐Epicatechin (Epi), a flavanol in cacao stimulates mitochondrial volume and cristae density and protein markers of skeletal muscle (SkM) mitochondrial biogenesis in mice. Type 2 diabetes mellitus (DM2) and heart failure (HF) are diseases associated with defects in SkM mitochondrial structure/function. A study was implemented to assess perturbations and to determine the effects of Epi‐rich cocoa in SkM mitochondrial structure and mediators of biogenesis. Five patients with DM2 and stage II/III HF consumed dark chocolate and a beverage containing approximately 100 mg of Epi per day for 3 months. We assessed changes in protein and/or activity levels of oxidative phosphorylation proteins, porin, mitofilin, nNOS, nitric oxide, cGMP, SIRT1, PGC1α, Tfam, and mitochondria volume and cristae abundance by electron microscopy from SkM. Apparent major losses in normal mitochondria structure were observed before treatment. Epi‐rich cocoa increased protein and/or activity of mediators of biogenesis and cristae abundance while not changing mitochondrial volume density. Epi‐rich cocoa treatment improves SkM mitochondrial structure and in an orchestrated manner, increases molecular markers of mitochondrial biogenesis resulting in enhanced cristae density. Future controlled studies are warranted using Epi‐rich cocoa (or pure Epi) to translate improved mitochondrial structure into enhanced cardiac and/or SkM muscle function. Clin Trans Sci 2012; Volume 5: 43–47 PMID:22376256

Functional Tricuspid Regurgitation Caused by Chronic Atrial Fibrillation: A Real-Time 3-Dimensional Transesophageal Echocardiography Study.

PubMed

Utsunomiya, Hiroto; Itabashi, Yuji; Mihara, Hirotsugu; Berdejo, Javier; Kobayashi, Sayuki; Siegel, Robert J; Shiota, Takahiro

2017-01-01

Functional tricuspid regurgitation (TR) with a structurally normal tricuspid valve (TV) may occur secondary to chronic atrial fibrillation (AF). However, the clinical and echocardiographic differences according to functional TR subtypes are unclear. Therefore, characterization of functional TR because of chronic AF (AF-TR) remains undetermined. To investigate the prevalence of AF-TR, 437 patients with moderate to severe TR underwent 3-dimensional (3D) transesophageal echocardiography. TR severity was determined by the averaged vena contracta width on apical and parasternal inflow views. The prevalence of AF-TR was 9.2%, whereas that of functional TR because of left-sided heart disease was 45.3%. Clinical features of AF-TR included advanced age, female sex, greater right atrial than left atrial enlargement and lower systolic pulmonary artery pressure compared with left-sided heart disease-TR with sinus rhythm (all P<0.05). In 3D TV assessment, patients with AF-TR had a larger TV annular area with weaker annular contraction (both P<0.001) but a smaller tethering angle (P<0.001) despite a similar leaflet coaptation status compared with patients with left-sided heart disease-TR with sinus rhythm. On multivariable analysis, only the TV annular area in midsystole (coefficient, 0.059; 95% confidence interval, 0.041-0.078 per 100 mm 2 ; P<0.001) was associated with TR severity in AF-TR. The annular area was more closely correlated with the right atrial volume than right ventricular end-systolic volume in AF-TR (P<0.001). AF-TR is not rare and is associated with advanced age and right atrial enlargement. TV deformations and their association with right heart remodeling differ between AF-TR and left-sided heart disease-TR. Our results suggest that in patients with TR secondary to AF, TV annuloplasty should be effective because this entity has annular dilatation without leaflet deformation. © 2017 American Heart Association, Inc.

Assessment and Management of Volume Overload and Congestion in Chronic Heart Failure: Can Measuring Blood Volume Provide New Insights?

PubMed

Miller, Wayne L

2017-01-01

Volume overload and fluid congestion remain primary clinical challenges in the assessment and management of patients with chronic heart failure (HF). The pathophysiology of volume regulation is complex, and the simple concept of passive intravascular fluid accumulation is not adequate. The dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to the central pulmonary circulation need to be taken into account in strategies of volume management. Clinical bedside evaluations and right heart hemodynamic assessments can alert of changes in volume status, but only the quantitative measurement of total blood volume can help identify the heterogeneity in plasma volume and red blood cell mass that are features of volume overload in chronic HF. The quantitative assessment of intravascular volume is an effective tool to help guide individualized, appropriate therapy. Not all volume overload is the same, and the measurement of intravascular volume identifies heterogeneity to guide tailored therapy.

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.

Preserved semantic access in global amnesia and hippocampal damage.

PubMed

Giovagnoli, A R; Erbetta, A; Bugiani, O

2001-12-01

C.B., a right-handed 33-year-old man, presented with anterograde amnesia after acute heart block. Cognitive abilities were normal except for serious impairment of long-term episodic memory. The access to semantic information was fully preserved. Magnetic resonance showed high signal intensity and marked volume loss in the hippocampus bilaterally; the left and right parahippocampal gyrus, lateral occipito-temporal gyrus, inferior temporal gyrus, and lateral temporal cortex were normal. This case underlines that global amnesia associated with hippocampal damage does not affect semantic memory. Although the hippocampus is important in retrieving context-linked information, its role is not so crucial in retrieving semantic contents. Cortical areas surrounding the hippocampus and lateral temporal areas might guide the recall of semantic information.

Brain volumes predict neurodevelopment in adolescents after surgery for congenital heart disease.

PubMed

von Rhein, Michael; Buchmann, Andreas; Hagmann, Cornelia; Huber, Reto; Klaver, Peter; Knirsch, Walter; Latal, Beatrice

2014-01-01

Patients with complex congenital heart disease are at risk for neurodevelopmental impairments. Evidence suggests that brain maturation can be delayed and pre- and postoperative brain injury may occur, and there is limited information on the long-term effect of congenital heart disease on brain development and function in adolescent patients. At a mean age of 13.8 years, 39 adolescent survivors of childhood cardiopulmonary bypass surgery with no structural brain lesions evident through conventional cerebral magnetic resonance imaging and 32 healthy control subjects underwent extensive neurodevelopmental assessment and cerebral magnetic resonance imaging. Cerebral scans were analysed quantitatively using surface-based and voxel-based morphometry. Compared with control subjects, patients had lower total brain (P = 0.003), white matter (P = 0.004) and cortical grey matter (P = 0.005) volumes, whereas cerebrospinal fluid volumes were not different. Regional brain volume reduction ranged from 5.3% (cortical grey matter) to 11% (corpus callosum). Adolescents with cyanotic heart disease showed more brain volume loss than those with acyanotic heart disease, particularly in the white matter, thalami, hippocampi and corpus callosum (all P-values < 0.05). Brain volume reduction correlated significantly with cognitive, motor and executive functions (grey matter: P < 0.05, white matter: P < 0.01). Our findings suggest that there are long-lasting cerebral changes in adolescent survivors of cardiopulmonary bypass surgery for congenital heart disease and that these changes are associated with functional outcome.

Measuring hemodynamics in the developing heart tube with four-dimensional gated Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Jenkins, Michael W.; Peterson, Lindsy; Gu, Shi; Gargesha, Madhusudhana; Wilson, David L.; Watanabe, Michiko; Rollins, Andrew M.

2010-11-01

Hemodynamics is thought to play a major role in heart development, yet tools to quantitatively assess hemodynamics in the embryo are sorely lacking. The especially challenging analysis of hemodynamics in the early embryo requires new technology. Small changes in blood flow could indicate when anomalies are initiated even before structural changes can be detected. Furthermore, small changes in the early embryo that affect blood flow could lead to profound abnormalities at later stages. We present a demonstration of 4-D Doppler optical coherence tomography (OCT) imaging of structure and flow, and present several new hemodynamic measurements on embryonic avian hearts at early stages prior to the formation of the four chambers. Using 4-D data, pulsed Doppler measurements could accurately be attained in the inflow and outflow of the heart tube. Also, by employing an en-face slice from the 4-D Doppler image set, measurements of stroke volume and cardiac output are obtained without the need to determine absolute velocity. Finally, an image plane orthogonal to the blood flow is used to determine shear stress by calculating the velocity gradient normal to the endocardium. Hemodynamic measurements will be crucial to identifying genetic and environmental factors that lead to congenital heart defects.

Flecainide-induced proarrhythmia is attributed to abnormal changes in repolarization and refractoriness in perfused guinea-pig heart.

PubMed

Osadchii, Oleg E

2012-11-01

Flecainide is nonselective Na(+) channel blocker which may also inhibit I(Kr), the rapid component of the delayed rectifier. This study was designed to explore if proarrhythmic responses to flecainide noted in cardiac patients may be partly attributed to abnormal changes in repolarization and refractoriness. Monophasic action potential duration (APD) and effective refractory periods (ERP) were assessed at distinct epicardial and endocardial sites along with volume-conducted ECG recordings in isolated perfused guinea-pig heart preparations. Flecainide was found to prolong ventricular repolarization, with effect being greater at the left ventricular compared with the right ventricular epicardium. This change translated to reversal of the normal right ventricular-to-left ventricular transepicardial APD difference determined before drug infusion. An inverse correlation between local epicardial APD and corresponding activation time values seen at baseline was eliminated in flecainide-treated hearts, indicating the activation-to-repolarization uncoupling. Over transmural plane, flecainide produced a greater ERP lengthening at endocardium than epicardium, thus markedly increasing ERP dispersion across ventricular wall. Spontaneous short-lasting episodes of monomorphic ventricular tachycardia were observed in 45% of heart preparations upon flecainide infusion. In conclusion, in nonischemic guinea-pig heart, flecainide-induced proarrhythmia may be partly attributed to abnormal spatial gradients in repolarization and refractoriness and impaired transepicardial activation-to-repolarization coupling.

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

Variations from morning to afternoon of middle cerebral and umbilical artery blood flow, and fetal heart rate variability, and fetal characteristics in the normally developing fetus.

PubMed

Avitan, Tehila; Sanders, Ari; Brain, Ursula; Rurak, Dan; Oberlander, Tim F; Lim, Ken

2018-05-01

To determine if there are changes in maternal uterine blood flow, fetal brain blood flow, fetal heart rate variability, and umbilical blood flow between morning (AM) and afternoon (PM) in healthy, uncomplicated pregnancies. In this prospective study, 68 uncomplicated singleton pregnancies (mean 35 + 0.7 weeks gestation) underwent a standard observational protocol at both 08:00 (AM) and 13:30 (PM) of the same day. This protocol included Doppler measurements of uterine, umbilical, and fetal middle cerebral artery (MCA) volume flow parameters (flow, HR, peak systolic velocity [PSV], PI, and RI) followed by computerized cardiotocography. Standard descriptive statistics, χ 2 and t tests were used where appropriate. P < .05 was considered significant. A significant increase in MCA flow and MCA PSV was observed in the PM compared to the AM. This was accompanied by a fall in MCA resistance. Higher umbilical artery resistance indices were also observed in the PM compared to AM. In contrast, fetal heart rate characteristics, maternal uterine artery Doppler flow and resistance indices did not vary significantly between the AM and PM. In normal pregnancies, variations in fetal cerebral and umbilical blood flow parameters were observed between AM and PM independent of other fetal movements or baseline fetal heart rate. In contrast, uterine flow parameters remained stable across the day. These findings may have implications for the use of serial Doppler parameters used to guide clinical management in high-risk pregnancies. © 2017 Wiley Periodicals, Inc.

[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.

Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera

DOEpatents

Majewski, Stanislaw [Morgantown, VA; Umeno, Marc M [Woodinville, WA

2011-09-13

A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.

Desmin loss and mitochondrial damage precede left ventricular systolic failure in volume overload heart failure.

PubMed

Guichard, Jason L; Rogowski, Michael; Agnetti, Giulio; Fu, Lianwu; Powell, Pamela; Wei, Chih-Chang; Collawn, James; Dell'Italia, Louis J

2017-07-01

Heart failure due to chronic volume overload (VO) in rats and humans is characterized by disorganization of the cardiomyocyte desmin/mitochondrial network. Here, we tested the hypothesis that desmin breakdown is an early and continuous process throughout VO. Male Sprague-Dawley rats had aortocaval fistula (ACF) or sham surgery and were examined 24 h and 4 and 12 wk later. Desmin/mitochondrial ultrastructure was examined by transmission electron microscopy (TEM) and immunohistochemistry (IHC). Protein and kinome analysis were performed in isolated cardiomyocytes, and desmin cleavage was assessed by mass spectrometry in left ventricular (LV) tissue. Echocardiography demonstrated a 40% decrease in the LV mass-to-volume ratio with spherical remodeling at 4 wk with ACF and LV systolic dysfunction at 12 wk. Starting at 24 h and continuing to 4 and 12 wk, with ACF there is TEM evidence of extensive mitochondrial clustering, IHC evidence of disorganization associated with desmin breakdown, and desmin protein cleavage verified by Western blot analysis and mass spectrometry. IHC results revealed that ACF cardiomyocytes at 4 and 12 wk had perinuclear translocation of αB-crystallin from the Z disk with increased α, β-unsaturated aldehyde 4-hydroxynonelal. Use of protein markers with verification by TUNEL staining and kinome analysis revealed an absence of cardiomyocyte apoptosis at 4 and 12 wk of ACF. Significant increases in protein indicators of mitophagy were countered by a sixfold increase in p62/sequestosome-1, which is indicative of an inability to complete autophagy. An early and continuous disruption of the desmin/mitochondrial architecture, accompanied by oxidative stress and inhibition of apoptosis and mitophagy, suggests its causal role in LV dilatation and systolic dysfunction in VO. NEW & NOTEWORTHY This study provides new evidence of early onset (24 h) and continuous (4-12 wk) desmin misarrangement and disruption of the normal sarcomeric and mitochondrial architecture throughout the progression of volume overload heart failure, suggesting a causal link between desmin cleavage and mitochondrial disorganization and damage.

Bradycardia

MedlinePlus

... Easily tiring during physical activity When a slow heart rate is normal A resting heart rate slower than 60 beats a minute is normal ... often starts in the sinus node. A slow heart rate might occur because the sinus node: Discharges electrical ...

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

Morphological and biochemical examination of Cosmos 1887 rat heart tissue. Part 1: Ultrastructure

NASA Technical Reports Server (NTRS)

Philpott, D. E.; Popova, I. A.; Kato, K.; Stevenson, J.; Miquel, J.; Sapp, W.

1990-01-01

Morphological changes were observed in the left ventricle of rat heart tissue from animals flown on the Cosmos 1887 biosatellite for 12.5 days. These tissues were compared to the synchronous and vivarium control hearts. While many normal myofibrils were observed, others exhibited ultrastructural alterations, i.e., damaged and irregular-shaped mitochondria and generalized myofibrillar edema. Analysis of variance (ANOVA) of the volume density data revealed a statistically significant increase in glycogen and a significant decrease in mitochondria compared to the synchronous and vivarium controls. Point counting indicated an increase in lipid and myeloid bodies and a decrease in microtubules, but these changes were not statistically significant. In addition, the flight animals exhibited some patchy loss of protofibrils (actin and myosin filaments) and some abnormal supercontracted myofibrils that were not seen in the controls. This study was undertaken to gain insight into the mechanistic aspects of cardiac changes in both animals and human beings as a consequence of space travel. Cardiac hypotrophy and fluid shifts have been observed after actual or simulated weightlessness and raise concerns about the functioning of the heart and circulatory system during and after travel in space.

Pharmacological heart rate lowering in patients with a preserved ejection fraction-review of a failing concept.

PubMed

Meyer, Markus; Rambod, Mehdi; LeWinter, Martin

2018-07-01

Epidemiological studies have demonstrated that high resting heart rates are associated with increased mortality. Clinical studies in patients with heart failure and reduced ejection fraction have shown that heart rate lowering with beta-blockers and ivabradine improves survival. It is therefore often assumed that heart rate lowering is beneficial in other patients as well. Here, we critically appraise the effects of pharmacological heart rate lowering in patients with both normal and reduced ejection fraction with an emphasis on the effects of pharmacological heart rate lowering in hypertension and heart failure. Emerging evidence from recent clinical trials and meta-analyses suggest that pharmacological heart rate lowering is not beneficial in patients with a normal or preserved ejection fraction. This has just begun to be reflected in some but not all guideline recommendations. The detrimental effects of pharmacological heart rate lowering are due to an increase in central blood pressures, higher left ventricular systolic and diastolic pressures, and increased ventricular wall stress. Therefore, we propose that heart rate lowering per se reproduces the hemodynamic effects of diastolic dysfunction and imposes an increased arterial load on the left ventricle, which combine to increase the risk of heart failure and atrial fibrillation. Pharmacologic heart rate lowering is clearly beneficial in patients with a dilated cardiomyopathy but not in patients with normal chamber dimensions and normal systolic function. These conflicting effects can be explained based on a model that considers the hemodynamic and ventricular structural effects of heart rate changes.

SU-E-T-62: Cardiac Toxicity in Dynamic Conformal Arc Therapy, Intensity-Modulated Radiation Therapy and Volumetric Modulated Arc Therapy of Lung Cancers

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

Ming, X; Zhang, Y; Yale University, New Haven, CT, US

2014-06-01

Purpose: The cardiac toxicity for lung cancer patients, each treated with dynamic conformal arc therapy (DAT), intensity-modulated radiation therapy (IMRT), or volumetric modulated arc therapy (VMAT) is investigated. Methods: 120 lung patients were selected for this study: 25 treated with DAT, 50 with IMRT and 45 with VMAT. For comparison, all plans were generated in the same treatment planning system, normalized such that the 100% isodose lines encompassed 95% of planning target volume. The plan quality was evaluated in terms of homogeneity index (HI) and 95% conformity index (%95 CI) for target dose coverage and mean dose, maximum dose, V{submore » 30} Gy as well as V{sub 5} Gy for cardiac toxicity analysis. Results: When all the plans were analyzed, the VMAT plans offered the best target coverage with 95% CI = 0.992 and HI = 1.23. The DAT plans provided the best heart sparing with mean heart dose = 2.3Gy and maximum dose = 11.6Gy, as compared to 5.7 Gy and 31.1 Gy by IMRT as well as 4.6 Gy and 30.9 Gy by VMAT. The mean V30Gy and V5Gy of the heart in the DAT plans were up to 11.7% lower in comparison to the IMRT and VMAT plans. When the tumor volume was considered, the VMAT plans spared up to 70.9% more doses to the heart when the equivalent diameter of the tumor was larger than 4cm. Yet the maximum dose to the heart was reduced the most in the DAT plans with up to 139.8% less than that of the other two plans. Conclusion: Overall, the VMAT plans achieved the best target coverage among the three treatment modalities, and would spare the heart the most for the larger tumors. The DAT plans appeared advantageous in delivering the least maximum dose to the heart as compared to the IMRT and VMAT plans.« less

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.

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.

SU-E-T-605: RapidArc Combined with DIBH Technique for Thoracic Esophageal Carcinoma: The Potential Value of Target Immobilization and Reduced Lung Density in Dose Escalation.

PubMed

Yin, Y; Liu, T; Zhai, D

2012-06-01

To compare the dosimetric benefits of Rapidarc (RA) combined with deep inspiration breath-hold (DIBH) with those of other standard techniques, including free breathing (FB) during fixed-field intensity modulated radiation therapy (IMRT) and dual arc RA, in the treatment of patients with thoracic esophageal carcinoma (EC). Ten patients with EC underwent computed tomography (CT) scans under 2 respiration conditions: free-breathing (FB) and DIBH. These scans were used to generate 3-dimensional conformal treatment plans. For breath-hold scans, the patients were brought to reproducible respiration levels using active breathing control (ABC) maneuvers. Planning target volumes (PTVs) for FB plans included a 0.5 cm margin for setup plus a 1 cm margin equal to the extent of tumor motion for respiration. PTVs for DIBH plans included a 0.5 cm margin for setup error and a 0.5 cm margin for residual uncertainty in tumor position. Using a dose level of 60 Gy to the PTV, three treatment plans were generated: IMRT-FB, RA-FB and RA-ABC, and the target and normal tissue volumes were compared, as were the dosimetry parameters. On average, the DIBH technique resulted in increased lung volumes compared with FB techniques. There was no significant differences in gross tumor volume between the two breathing states (p > 0.05); but PTV and heart volume were larger for FB than for DIBH (p < 0.05). The overall CI and HI for the RA-ABC plan was slightly inferior to those of the IMRT- FB and RA-FB plans (p < 0.05 each). With DIBH, the heart was partly out of the beam portals and the average mean heart dose was reduced. Compared with conventional FB, RA combined with DIBH significantly reduced cardiac and pulmonary doses without compromising the target coverage and may reduce treatment toxicity, enabling dose escalation in future prospective studies of patients with EC. © 2012 American Association of Physicists in Medicine.

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.

Association of auricular pressing and heart rate variability in pre-exam anxiety students.

PubMed

Wu, Wocao; Chen, Junqi; Zhen, Erchuan; Huang, Huanlin; Zhang, Pei; Wang, Jiao; Ou, Yingyi; Huang, Yong

2013-03-25

A total of 30 students scoring between 12 and 20 on the Test Anxiety Scale who had been exhibiting an anxious state > 24 hours, and 30 normal control students were recruited. Indices of heart rate variability were recorded using an Actiheart electrocardiogram recorder at 10 minutes before auricular pressing, in the first half of stimulation and in the second half of stimulation. The results revealed that the standard deviation of all normal to normal intervals and the root mean square of standard deviation of normal to normal intervals were significantly increased after stimulation. The heart rate variability triangular index, very-low-frequency power, low-frequency power, and the ratio of low-frequency to high-frequency power were increased to different degrees after stimulation. Compared with normal controls, the root mean square of standard deviation of normal to normal intervals was significantly increased in anxious students following auricular pressing. These results indicated that auricular pressing can elevate heart rate variability, especially the root mean square of standard deviation of normal to normal intervals in students with pre-exam anxiety.

Association of auricular pressing and heart rate variability in pre-exam anxiety students

PubMed Central

Wu, Wocao; Chen, Junqi; Zhen, Erchuan; Huang, Huanlin; Zhang, Pei; Wang, Jiao; Ou, Yingyi; Huang, Yong

2013-01-01

A total of 30 students scoring between 12 and 20 on the Test Anxiety Scale who had been exhibiting an anxious state > 24 hours, and 30 normal control students were recruited. Indices of heart rate variability were recorded using an Actiheart electrocardiogram recorder at 10 minutes before auricular pressing, in the first half of stimulation and in the second half of stimulation. The results revealed that the standard deviation of all normal to normal intervals and the root mean square of standard deviation of normal to normal intervals were significantly increased after stimulation. The heart rate variability triangular index, very-low-frequency power, low-frequency power, and the ratio of low-frequency to high-frequency power were increased to different degrees after stimulation. Compared with normal controls, the root mean square of standard deviation of normal to normal intervals was significantly increased in anxious students following auricular pressing. These results indicated that auricular pressing can elevate heart rate variability, especially the root mean square of standard deviation of normal to normal intervals in students with pre-exam anxiety. PMID:25206734

Hemodynamic-GUIDEd Management of Heart Failure

ClinicalTrials.gov

2018-03-29

Heart Failure; Heart Failure, Systolic; Heart Failure, Diastolic; Heart Failure NYHA Class II; Heart Failure NYHA Class III; Heart Failure NYHA Class IV; Heart Failure，Congestive; Heart Failure With Reduced Ejection Fraction; Heart Failure With Normal Ejection Fraction; Heart Failure; With Decompensation

Limited Ventricular Preload is the Main Reason for Reduced Stress Reserve After Atrial Baffle Repair.

PubMed

Eicken, Andreas; Michel, Julia; Hager, Alfred; Tanase, Daniel; Kaemmerer, Harald; Cleuziou, Julie; Hess, John; Ewert, Peter

2017-02-01

The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls. Median cardiac output was significantly lower in the ABR group (2.2 vs. 2.6 l/min/m 2 ; p = 0.015), and systemic resistance was significantly elevated (28.9 vs. 22.2 U m 2 ; p = 0.04) in comparison with normals. While stroke volume rose by 27% in the control group, it dropped by 7% in patients after ABR at atrial pacing (80/min). Stroke volume increase after dobutamine was significantly lower after ABR in comparison with normal controls (34 vs. 106%; p = 0.001). Higher NYHA class (p = 0.043), degree of tricuspid regurgitation (p = 0.009) and ventricular function (p = 0.028) were associated with lower stroke volume increase. Limited exercise capability of patients after ABR for TGA is primarily due to limited diastolic filling of the ventricles due to stiff non-compliant atrial pathways. Elevated systemic resistance may lead to severe myocardial hypertrophy with possible ischemia and contribute to the multifactorial decline of ventricular function in some patients.

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

Pleural space elastance and changes in oxygenation after therapeutic thoracentesis in ventilated patients with heart failure and transudative pleural effusions.

PubMed

Chen, Wei-Lin; Chung, Chi-Li; Hsiao, Shih-Hsin; Chang, Shi-Chuan

2010-08-01

Therapeutic thoracentesis (TT) is required in patients with refractory pleural effusions and impaired oxygenation. In this study, the relationship between pleural space elastance (PE) and changes in oxygenation after TT was investigated in ventilated patients with heart failure and transudative pleural effusions. Twenty-six mechanically ventilated patients with heart failure and significant transudative effusions, who were undergoing TT, were studied. The effusion was drained as completely as possible, with monitoring of pleural liquid pressure (Pliq) and chest symptoms. The volume of effusion removed, the changes in Pliq during TT, PE and arterial blood gases before and after TT were recorded. The mean volume of effusion removed was 1011.9 +/- 58.2 mL. The mean Pliq decreased from 14.5 +/- 1.0 to 0.1 +/- 1.5 cm H(2)O after TT, and the mean PE was 15.3 +/- 1.8 cm H(2)O/L. TT significantly increased the mean ratio of PaO(2)/fraction of inspired oxygen (FiO(2)) from 243.2 +/- 19.9 to 336.0 +/- 17.8 mm Hg (P < 0.0001). The changes in PaO(2)/FiO(2) ratio after TT were inversely correlated with PE (r = -0.803, P < 0.0001). The 14 patients (54%) with normal PE (14.5 cm H(2)O/L). Measurement of PE during TT may be valuable for predicting improvement in oxygenation in ventilated patients with heart failure and pleural effusions. Patients with lower PE showed greater improvement in oxygenation after TT.

Technical Note: Dosimetric evaluation of Monte Carlo algorithm in iPlan for stereotactic ablative body radiotherapy (SABR) for lung cancer patients using RTOG 0813 parameters.

PubMed

Pokhrel, Damodar; Badkul, Rajeev; Jiang, Hongyu; Kumar, Pravesh; Wang, Fen

2015-01-08

For stereotactic ablative body radiotherapy (SABR) in lung cancer patients, Radiation Therapy Oncology Group (RTOG) protocols currently require radiation dose to be calculated using tissue heterogeneity corrections. Dosimetric criteria of RTOG 0813 were established based on the results obtained from non-Monte Carlo (MC) algorithms, such as superposition/convolutions. Clinically, MC-based algorithms are now routinely used for lung SABR dose calculations. It is essential to confirm that MC calculations in lung SABR meet RTOG guidelines. This report evaluates iPlan MC plans for SABR in lung cancer patients using dose-volume histogram normalization per current RTOG 0813 compliance criteria. Eighteen Stage I-II non-small cell lung cancer (NSCLC) patients with centrally located tumors, who underwent MC-based lung SABR with heterogeneity correction using X-ray Voxel Monte Carlo (XVMC) algorithm (BrainLAB iPlan version 4.1.2), were analyzed. Total dose of 60 Gy in 5 fractions was delivered to planning target volume (PTV) with at least V100% = 95%. Internal target volumes (ITVs) were delineated on maximum intensity projection (MIP) images of 4D CT scans. PTV (ITV + 5 mm margin) volumes ranged from 10.0 to 99.9 cc (mean = 36.8 ± 20.7 cc). Organs at risk (OARs) were delineated on average images of 4D CT scans. Optimal clinical MC SABR plans were generated using a combination of non-coplanar conformal arcs and beams for the Novalis-TX consisting of high definition multileaf collimators (MLCs) and 6 MV-SRS (1000 MU/min) mode. All plans were evaluated using the RTOG 0813 high and intermediate dose spillage criteria: conformity index (R100%), ratio of 50% isodose volume to the PTV (R50%), maximum dose 2 cm away from PTV in any direction (D2 cm), and percent of normal lung receiving 20 Gy (V20) or more. Other organs-at-risk (OARs) doses were tabulated, including the volume of normal lung receiving 5 Gy (V5), maximum cord dose, dose to < 15 cc of heart, and dose to <5 cc of esophagus. Only six out of 18 patients met all RTOG 0813 compliance criteria. Eight of 18 patients had minor deviations in R100%, four in R50%, and nine in D2 cm. However, only one patient had minor deviation in V20. All other OARs doses, such as maximum cord dose, dose to < 15 cc of heart, and dose to < 5 cc of esophagus, were satisfactory for RTOG criteria, except for one patient, for whom the dose to < 15 cc of heart was higher than RTOG guidelines. The preliminary results for our limited iPlan XVMC dose calculations indicate that the majority (i.e., 2/3) of our patients had minor deviations in the dosimetric guidelines set by RTOG 0813 protocol in one way or another. When using an exclusive highly sophisticated XVMC algorithm, the RTOG 0813 dosimetric compliance criteria such as R100% and D2 cm may need to be revisited. Based on our limited number of patient datasets, in general, about 6% for R100% and 9% for D2 cm corrections could be applied to pass the RTOG 0813 compliance criteria in most of those patients. More patient plans need to be evaluated to make recommendation for R50%. No adjustment is necessary for OAR dose tolerances, including normal lung V20. In order to establish new MC specific dose parameters, further investigation with a large cohort of patients including central, as well as peripheral lung tumors, is anticipated and strongly recommended.

Ischemic preconditioning fails to confer additional protection against ischemia-reperfusion injury in the hypothyroid rat heart.

PubMed

Mourouzis, I; Dimopoulos, A; Saranteas, T; Tsinarakis, N; Livadarou, E; Spanou, D; Kokkinos, A D; Xinaris, C; Pantos, C; Cokkinos, D V

2009-01-01

There is accumulating evidence showing that ischemic preconditioning (PC) may lose its cardioprotective effect in the diseased states. The present study investigated whether PC can be effective in hypothyroidism, a clinical condition which is common and often accompanies cardiac diseases such as heart failure and myocardial infarction. Hypothyroidism was induced in rats by 3-week administration of 6n-propyl-2-thiouracil in water (0.05 %). Normal and hypothyroid hearts (HYPO) were perfused in Langendorff mode and subjected to 20 min of zero-flow global ischemia and 45 min of reperfusion. A preconditioning protocol (PC) was also applied prior to ischemia. HYPO hearts had significantly improved post-ischemic recovery of left ventricular developed pressure, end-diastolic pressure and reduced lactate dehydrogenase release. Furthermore, phospho-JNK and p38 MAPK levels after ischemia and reperfusion were 4.0 and 3.0 fold lower in HYPO as compared to normal hearts (P<0.05). A different response to PC was observed in normal than in HYPO hearts. PC improved the post-ischemic recovery of function and reduced the extent of injury in normal hearts but had no additional effect on the hypothyroid hearts. This response, in the preconditioned normal hearts, resulted in 2.5 and 1.8 fold smaller expression of the phospho-JNK and phospho-p38 MAPK levels at the end of reperfusion, as compared to non-PC hearts (P<0.05), while in HYPO hearts, no additional reduction in the phosphorylation of these kinases was observed after PC. Hypothyroid hearts appear to be tolerant to ischemia-reperfusion injury. This response may be, at least in part, due to the down-regulation of ischemia-reperfusion induced activation of JNKs and p38 MAPK kinases. PC is not associated with further reduction in the activation of these kinases in the hypothyroid hearts and fails to confer added protection in those hearts.

Cardiorespiratory functional assessment after pediatric heart transplantation.

PubMed

Pastore, E; Turchetta, A; Attias, L; Calzolari, A; Giordano, U; Squitieri, C; Parisi, F

2001-12-01

Limited data are available on the exercise capacity of young heart transplant recipients. The aim of this study was therefore to assess cardiorespiratory responses to exercise in this group of patients. Fourteen consecutive heart transplant recipients (six girls and eight boys, age-range 5-15 yr) and 14 healthy matched controls underwent a Bruce treadmill test to determine: duration of test; resting and maximum heart rates; maximum systolic blood pressure; peak oxygen consumption (VO2 peak); and cardiac output. Duration of test and heart rate increase were then compared with: time since transplantation, rejections per year, and immunosuppressive drugs received. The recipients also underwent the following lung function tests: forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). When compared with healthy controls, transplant recipients had tachycardia at rest (126 +/- 3.7 beats/min; p < 0.001); significantly reduced tolerance (9.3 +/- 0.4 min; p < 0.001), a maximum heart rate of 169 +/- 5.4 beats/min (p < 0.05); a cardiac output of 5.65 +/- 0.6 L/min (p < 0.05); and a lower heart-rate increase from rest to peak exercise (p < 0.001) but a similar VO2 peak. The heart-rate increase correlated significantly with time post-transplant (r = 0.55; p < 0.05), number of rejection episodes per year (r = - 0.63; p < 0.05), and number of immunosuppressive drugs (r = - 0.60; p < 0.05). The recipients had normal FVC and FEV1 values. After surgery, few heart transplant recipients undertake physical activity, possibly owing to over-protective parents and teachers and to a lack of suitable supervised facilities. The authors stress the importance of a cardiorespiratory functional evaluation for assessment of health status and to encourage recipients, if possible, to undertake regular physical activity.

The Safety and Effectiveness of Flecainide in Children in the Current Era.

PubMed

Cunningham, Taylor; Uzun, Orhan; Morris, Rachel; Franciosi, Sonia; Wong, Amos; Jeremiasen, Ida; Sherwin, Elizabeth; Sanatani, Shubhayan

2017-12-01

This retrospective study sought to determine the safety and effectiveness of flecainide in children with normal hearts and those with congenital heart disease (CHD) or cardiomyopathy (CMO). Baseline and follow-up data at two pediatric cardiology sites were queried (2000-2015); a total of 175 patients (20 with CHD and two with CMO) receiving flecainide were assessed. When comparing patients with CHD to those with normal hearts, patients with CHD were younger at diagnosis (median age 19 days; IQR 3-157.5 days vs normal heart patients median age 21 days; IQR 7-172 days, p = 0.4) and severe cardiac dysfunction was more prevalent (30% in CHD patients vs 8% in normal heart patients, p = 0.009). Treatment duration did not differ between the two groups (CHD patients median duration 52 weeks; IQR 27-91.5 weeks vs normal heart patients median duration 55 weeks; IQR 32-156 weeks, p = 0.5). Cardiac dysfunction resulting in flecainide discontinuation occurred in two patients (1%), one with CHD and one without. Three patients experienced proarrhythmia (2%) and there were no cardiac arrests during follow-up. There was one death in this cohort in a patient with severe CHD and an RSV infection (<1%). Arrhythmia control did not differ between the groups (90% in CHD patients vs 77% in normal heart patients, p = 0.2). Flecainide was well tolerated in this cohort, with fewer than 3% discontinuing medication due to flecainide-associated adverse events. Contrary to adult studies, there was no difference in the incidence of adverse events between patients with normal hearts and patients with CHD. Flecainide is a safe and effective antiarrhythmic medication, even for children with underlying CHD.

The agreement between 3D, standard 2D and triplane 2D speckle tracking: effects of image quality and 3D volume rate.

PubMed

Trache, Tudor; Stöbe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas

2014-12-01

Comparison of 3D and 2D speckle tracking performed on standard 2D and triplane 2D datasets of normal and pathological left ventricular (LV) wall-motion patterns with a focus on the effect that 3D volume rate (3DVR), image quality and tracking artifacts have on the agreement between 2D and 3D speckle tracking. 37 patients with normal LV function and 18 patients with ischaemic wall-motion abnormalities underwent 2D and 3D echocardiography, followed by offline speckle tracking measurements. The values of 3D global, regional and segmental strain were compared with the standard 2D and triplane 2D strain values. Correlation analysis with the LV ejection fraction (LVEF) was also performed. The 3D and 2D global strain values correlated good in both normally and abnormally contracting hearts, though systematic differences between the two methods were observed. Of the 3D strain parameters, the area strain showed the best correlation with the LVEF. The numerical agreement of 3D and 2D analyses varied significantly with the volume rate and image quality of the 3D datasets. The highest correlation between 2D and 3D peak systolic strain values was found between 3D area and standard 2D longitudinal strain. Regional wall-motion abnormalities were similarly detected by 2D and 3D speckle tracking. 2DST of triplane datasets showed similar results to those of conventional 2D datasets. 2D and 3D speckle tracking similarly detect normal and pathological wall-motion patterns. Limited image quality has a significant impact on the agreement between 3D and 2D numerical strain values.

Left-Ventricular Energetics in Pulmonary Arterial Hypertension-Induced Right-Ventricular Hypertrophic Failure

PubMed Central

Han, June-Chiew; Guild, Sarah-Jane; Pham, Toan; Nisbet, Linley; Tran, Kenneth; Taberner, Andrew J.; Loiselle, Denis S.

2018-01-01

Pulmonary arterial hypertension (PAH) alters the geometries of both ventricles of the heart. While the right ventricle (RV) hypertrophies, the left ventricle (LV) atrophies. Multiple lines of clinical and experimental evidence lead us to hypothesize that the impaired stroke volume and systolic pressure of the LV are a direct consequence of the effect of pressure overload in the RV, and that atrophy in the LV plays only a minor role. In this study, we tested this hypothesis by examining the mechanoenergetic response of the atrophied LV to RV hypertrophy in rats treated with monocrotaline. Experiments were performed across multiple-scales: the whole-heart in vivo and ex vivo, and its trabeculae in vitro. Under the in vivo state where the RV was pressure-overloaded, we measured reduced systemic blood pressure and LV ventricular pressure. In contrast, under both ex vivo and in vitro conditions, where the effect of RV pressure overload was circumvented, we found that LV was capable of developing normal systolic pressure and stress. Nevertheless, LV atrophy played a minor role in that LV stroke volume remained lower, thereby contributing to lower LV mechanical work output. Concomitantly lower oxygen consumption and change of enthalpy were observed, and hence LV energy efficiency was unchanged. Our internally consistent findings between working-heart and trabecula experiments explain the rapid improvement of LV systolic function observed in patients with chronic pulmonary hypertension following surgical relief of RV pressure overload. PMID:29375394

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

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.

A study on quantitative analysis of field size and dose by using gating system in 4D conformal radiation treatment

NASA Astrophysics Data System (ADS)

Ji, Youn-Sang; Dong, Kyung-Rae; Kim, Chang-Bok; Chung, Woon-Kwan; Cho, Jae-Hwan; Lee, Hae-Kag

2012-10-01

This study evaluated the gating-based 4-D conformal radiation therapy (4D-CT) treatment planning by a comparison with the common 3-D conformal radiation therapy (3D-CT) treatment planning and examined the change in treatment field size and dose to the tumors and adjacent normal tissues because an unnecessary dose is also included in the 3-D treatment planning for the radiation treatment of tumors in the chest and abdomen. The 3D-CT and gating-based 4D-CT images were obtained from patients who had undergone radiation treatment for chest and abdomen tumors in the oncology department. After establishing a treatment plan, the CT treatment and planning system were used to measure the change in field size for analysis. A dose volume histogram (DVH) was used to calculate the appropriate dose to planning target volume (PTV) tumors and adjacent normal tissue. The difference in the treatment volume of the chest was 0.6 and 0.83 cm on the X- and Y-axis, respectively, for the gross tumor volume (GTV). Accordingly, the values in the 4D-CT treatment planning were smaller and the dose was more concentrated by 2.7% and 0.9% on the GTV and clinical target volume (CTV), respectively. The normal tissues in the surrounding normal tissues were reduced by 3.0%, 7.2%, 0.4%, 1.7%, 2.6% and 0.2% in the bronchus, chest wall, esophagus, heart, lung and spinal cord, respectively. The difference in the treatment volume of the abdomen was 0.72 cm on the X-axis and 0.51 cm on the Y-axis for the GTV; and 1.06 cm on the X-axis and 1.85 cm on the Y-axis for the PTV. Therefore, the values in the 4D-CT treatment planning were smaller. The dose was concentrated by 6.8% and 4.3% on the GTV and PTV, respectively, whereas the adjacent normal tissues in the cord, Lt. kidney, Rt. kidney, small bowels and whole liver were reduced by 3.2%, 4.2%, 1.5%, 6.2% and 12.7%, respectively. The treatment field size was smaller in volume in the case of the 4D-CT treatment planning. In the DVH, the 4D-CT treatment planning showed a higher dose concentration on the part to be treated than the 3D-CT treatment planning with a lower dose to the adjacent normal tissues. Overall, the gating-based 4D-CT treatment planning is believed to be more helpful than the 3D-CT treatment planning.

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.

[Segmental wall movement of the left ventricle in healthy persons and myocardial infarct patients studied by a catheter-less nuclear medical method (camera-cinematography of the heart)].

PubMed

Geffers, H; Sigel, H; Bitter, F; Kampmann, H; Stauch, M; Adam, W E

1976-08-01

Camera-Kinematography is a nearly noninvasive method to investigate regional motion of the myocard, and allows evaluation of the function of the heart. About 20 min after injection of 15-20 mCi of 99mTC-Human-Serum-Albumin, when the tracer is distributed homogenously within the bloodpool, data acquisition starts. Myocardial wall motion is represented in an appropriate quasi three-dimensional form. In this representation scars can be revealed as "silent" (akinetic) regions, aneurysms by asynchronic motion. Time activity curves for arbitrarily chosen regions can be calculated and give an equivalent for regional volume changes. 16 patients with an old infarction have been investigated. In fourteen cases the location and extent of regions with abnormal motion could be evaluated. Only two cases of a small posterior wall infarction did not show deviations from normal contraction pattern.

[Effect of transurethral resection of the prostate on the state of patients with ischemic heart disease].

PubMed

Belugin, R S; Zabusov, A V; Zhemchugov, A V

2004-01-01

The water-salt equilibrium and the degree of endogenous intoxication (albumin fluorescence test) were examined in 60 patients with transurethral resection of the prostate (TURP), 40 of whom had ischemic heart disease (IHD). Body temperature, ECG, ST segment and echocardioscopy were daily monitored perioperatively in all patients. The results showed a lack of any pronounced changes in the water-salt equilibrium in TURP that lasted up to 1.5 hours and included big volumes of 5% glucose; they were also indicative of a lower postoperative binding albumin ability, which is normally most pronounced in patients with hyperthermia. As for the IHD patients, hyperthermia was found to be concurrent in them with the onset of ischemia of the myocardium and with its low contractive ability, which can be referred to as a significant factor in case of the above patients.

Vascular calcification abrogates the nicorandil mediated cardio-protection in ischemia reperfusion injury of rat heart.

PubMed

Ravindran, Sriram; Murali, Jeyashri; Amirthalingam, Sunil Kumar; Gopalakrishnan, Senthilkumar; Kurian, Gino A

2017-02-01

The present study was aimed to determine the efficacy of nicorandil in treating cardiac reperfusion injury with an underlying co-morbidity of vascular calcification (VC). Adenine diet was used to induce VC in Wistar rat and the heart was isolated to induce global ischemia reperfusion (IR) by Langendorff method, with and without the nicorandil (7.5mg/kg) pre-treatment and compared with those fed on normal diet. The adenine-treated rats displayed abnormal ECG changes and altered mitochondrial integrity compared to a normal rat heart. These hearts, when subjected to IR increased the infarct size, cardiac injury (measured by lactate dehydrogenase and creatine kinase activity in the coronary perfusate) and significantly altered the hemodynamics compared to the normal perfused heart. Nicorandil pretreatment in rat fed on normal diet enhanced the hemodynamics significantly (P<0.05) along with a substantial reduction in the mitochondrial dysfunction (measured by high ADP to oxygen consumption ratio, respiratory control ratio, enzyme activities and less swelling behavior) when subjected to IR. However, this cardio-protective effect of nicorandil was absent in rat heart with underlying calcification. Our results suggest that, the protective effect of nicorandil, a known mitochondrial ATP linked K + channel opener, against myocardial reperfusion injury was confined to normal rat heart. Copyright © 2017 Elsevier Inc. All rights reserved.

Global Intracoronary Infusion of Allogeneic Cardiosphere-Derived Cells Improves Ventricular Function and Stimulates Endogenous Myocyte Regeneration throughout the Heart in Swine with Hibernating Myocardium

PubMed Central

Suzuki, Gen; Weil, Brian R.; Leiker, Merced M.; Ribbeck, Amanda E.; Young, Rebeccah F.; Cimato, Thomas R.; Canty, John M.

2014-01-01

Background Cardiosphere-derived cells (CDCs) improve ventricular function and reduce fibrotic volume when administered via an infarct-related artery using the “stop-flow” technique. Unfortunately, myocyte loss and dysfunction occur globally in many patients with ischemic and non-ischemic cardiomyopathy, necessitating an approach to distribute CDCs throughout the entire heart. We therefore determined whether global intracoronary infusion of CDCs under continuous flow improves contractile function and stimulates new myocyte formation. Methods and Results Swine with hibernating myocardium from a chronic LAD occlusion were studied 3-months after instrumentation (n = 25). CDCs isolated from myocardial biopsies were infused into each major coronary artery (∼33×106 icCDCs). Global icCDC infusion was safe and while ∼3% of injected CDCs were retained, they did not affect ventricular function or myocyte proliferation in normal animals. In contrast, four-weeks after icCDCs were administered to animals with hibernating myocardium, %LADWT increased from 23±6 to 51±5% (p<0.01). In diseased hearts, myocyte proliferation (phospho-histone-H3) increased in hibernating and remote regions with a concomitant increase in myocyte nuclear density. These effects were accompanied by reductions in myocyte diameter consistent with new myocyte formation. Only rare myocytes arose from sex-mismatched donor CDCs. Conclusions Global icCDC infusion under continuous flow is feasible and improves contractile function, regresses myocyte cellular hypertrophy and increases myocyte proliferation in diseased but not normal hearts. New myocytes arising via differentiation of injected cells are rare, implicating stimulation of endogenous myocyte regeneration as the primary mechanism of repair. PMID:25402428

Global longitudinal strain in patients with suspected heart failure and a normal ejection fraction: does it improve diagnosis and risk stratification?

PubMed

Pellicori, Pierpaolo; Kallvikbacka-Bennett, Anna; Khaleva, Olga; Carubelli, Valentina; Costanzo, Pierluigi; Castiello, Teresa; Wong, Kenneth; Zhang, Jufen; Cleland, John G F; Clark, Andrew L

2014-01-01

Many patients have clinical, structural or bio-marker evidence of heart failure (HF) but a normal left ventricular ejection fraction (LVEF; HeFNEF). Measurement of global longitudinal strain (GLS) may add diagnostic and prognostic information. Patients with symptoms suggesting heart failure and LVEF ≥50% were studied: 76 had no substantial cardiac dysfunction (left atrial diameter (LAD) <40 mm and amino-terminal pro-brain natriuretic peptide (NTproBNP) <400 ng/l); 99 had "possible HeFNEF" (LAD ≥40 mm or NTproBNP ≥400 ng/l); and 138 had "definite HeFNEF" (LAD ≥40 mm and NTproBNP ≥400 ng/L). Mean LVEF was 58% in each subgroup. Patients with definite HeFNEF were older, more likely to have atrial fibrillation, had more symptoms and signs of fluid retention, were more likely to have right ventricular dysfunction and had higher pulmonary pressures than other groups. Mean GLS (SD) was less negative in patients with definite HeFNEF (-13.6 (3.0)% vs. possible HeFNEF: -15.2 (3.1)% vs. no substantial cardiac dysfunction: -15.9 (2.4)%; p < 0.001). GLS was -19.1 (2.1)% in 20 controls. During a median follow up of 647 days, cardiovascular death or an unplanned hospitalisation for heart failure occurred in 62 patients. In univariable analysis, GLS but not LVEF predicted events. However, in a multi-variable analysis, only urea, NTproBNP, left atrial volume, inferior vena cava diameter and atrial fibrillation independently predicted adverse outcome. GLS is abnormal in patients who have other evidence of HeFNEF, is associated with a worse prognosis in this population but is not a powerful independent predictor of outcome.

Evaluation of left ventricular Tei index (index of myocardial performance) in healthy dogs and dogs with mitral regurgitation.

PubMed

Teshima, Kenji; Asano, Kazushi; Iwanaga, Koji; Koie, Hiroshi; Uechi, Masami; Kato, Yuka; Kutara, Kenji; Kanno, Nobuyuki; Seki, Mamiko; Edamura, Kazuya; Hasegawa, Atsuhiko; Tanaka, Shigeo

2007-02-01

The left ventricular (LV) Tei index (index of myocardial performance) has been demonstrated to be clinically useful in estimating comprehensive LV function, including the systolic and diastolic performances, in various human cardiac diseases. The purposes of this study were to validate the correlation between the LV Tei index and LV function obtained by cardiac catheterization in healthy dogs, and to evaluate the LV Tei index in dogs with naturally occurring mitral regurgitation (MR). In healthy dogs, the LV Tei index was significantly correlated with the LV peak +dP/dt (r = -0.89) and LV peak -dP/dt (r=0.87). The LV Tei index significantly increased in dogs with MR compared with normal dogs and significantly increased with progressively more severe clinical signs due to heart failure. The elevation of the LV Tei index in dogs with symptomatic MR appears to be associated with shortening of ejection time. The LV Tei index significantly increased with age and was not correlated with heart rate and body weight in normal dogs. In conclusion, our study demonstrated that the LV Tei index was measurable in dogs and not influenced by heart rate and body weight. The LV Tei index significantly increased with the progression of clinical signs in MR dogs. In particular, the elevation of the LV Tei index in dogs with symptomatic MR due to shortening of ejection time may suggest LV systolic dysfunction and the decrement of forward stroke volume.

[Effects of trimetazidine on serum oxygen free radicals in congestive heart failure].

PubMed

Ma, Qi-lin; Xie, Yong; Zhang, Sai-dan

2002-12-28

To investigate the level of serum superoxide dismutase (SOD) and maiondialdehyde (MDA) and left ventricular systolic function in congestive heart failure (CHF) and to evaluate the influence of trimetazidine on them. Serum SOD and MDA were measured in 50 patients with heart function from grade two to four and 15 normal subjects. All the persons underwent echocardiography to determine the left ventricular end-systolic volume index (LVESVI) and the left ventricular ejection fraction (EF). The patients with CHF were randomly treated with trimetazidine plus routine therapy (n = 25) or routine therapy only (n = 25) for 8 weeks with evaluations made before and after the treatment. The SOD level and EF in the patients with CHF significantly decreased and the MDA level and LVESVI in those patients significantly increased compared with the normal subjects (P < 0.05); the severer the CHF, the greater the changes. After the treatment, the SOD level and EF increased significantly and MDA and LVESVI decreased significantly (P < 0.01) in both the trimetazidine and the conventional groups. And these changes were more obvious in the trimetazidine group than in the conventional group(P < 0.01). Oxygen free radicals play an important role in the pathophysiologic changes of CHF. The level of serum SOD and MDA can indicate the degree of CHF. Trimetazidine not only increases the level of SOD and decreases the level of MDA, but also improves the left ventricular systolic function.

Constitutive glycogen synthase kinase-3α/β activity protects against chronic β-adrenergic remodelling of the heart

PubMed Central

Webb, Ian G.; Nishino, Yasuhiro; Clark, James E.; Murdoch, Colin; Walker, Simon J.; Makowski, Marcus R.; Botnar, Rene M.; Redwood, Simon R.; Shah, Ajay M.; Marber, Michael S.

2010-01-01

Aims Glycogen synthase kinase 3 (GSK-3) signalling is implicated in the growth of the heart during development and in response to stress. However, its precise role remains unclear. We set out to characterize developmental growth and response to chronic isoproterenol (ISO) stress in knockin (KI) mice lacking the critical N-terminal serines, 21 of GSK-3α and 9 of GSK-3β respectively, required for inactivation by upstream kinases. Methods and results Between 5 and 15 weeks, KI mice grew more rapidly, but normalized heart weight and contractile performance were similar to wild-type (WT) mice. Isolated hearts of both genotypes responded comparably to acute ISO infusion with increases in heart rate and contractility. In WT mice, chronic subcutaneous ISO infusion over 14 days resulted in cardiac hypertrophy, interstitial fibrosis, and impaired contractility, accompanied by foetal gene reactivation. These effects were all significantly attenuated in KI mice. Indeed, ISO-treated KI hearts demonstrated reversible physiological remodelling traits with increased stroke volume and a preserved contractile response to acute adrenergic stimulation. Furthermore, simultaneous pharmacological inhibition of GSK-3 in KI mice treated with chronic subcutaneous ISO recapitulated the adverse remodelling phenotype seen in WT hearts. Conclusion Expression of inactivation-resistant GSK-3α/β does not affect eutrophic myocardial growth but protects against pathological hypertrophy induced by chronic adrenergic stimulation, maintaining cardiac function and attenuating interstitial fibrosis. Accordingly, strategies to prevent phosphorylation of Ser-21/9, and consequent inactivation of GSK-3α/β, may enable a sustained cardiac response to chronic β-agonist stimulation while preventing pathological remodelling. PMID:20299330

Relation of N-Terminal Pro-B-Type Natriuretic Peptide and Left Ventricular Diastolic Function to Exercise Tolerance in Patients With Significant Valvular Heart Disease and Normal Left Ventricular Systolic Function.

PubMed

Hwang, Ji-Won; Park, Sung-Ji; Cho, Eun Jeong; Kim, Eun Kyoung; Lee, Ga Yeon; Chang, Sung-A; Choi, Jin-Oh; Lee, Sang-Chol; Park, Seung Woo

2017-06-01

An association between N-terminal prohormone brain natriuretic peptide (NT-proBNP) and exercise tolerance in patients with valvular heart disease (VHD) has been suggested; however, there are few data available regarding this relation. The aim of this study is to evaluate the correlation between exercise tolerance and NT-proBNP in patients with asymptomatic or mildly symptomatic significant VHD and normal left ventricular ejection fraction (LV EF). A total of 96 patients with asymptomatic or mildly symptomatic VHD and normal LV EF (≥50%) underwent cardiopulmonary exercise echocardiography. NT-proBNP levels were determined at baseline and after exercise in 3 hours. Patients were divided in 2 groups based on lower (<26 ml/kg/min, n = 47) or higher (≥26 ml/kg/min, n = 49) peak oxygen consumption (VO 2 ) as a representation of exercise tolerance. In the 2 groups, after adjusting for age and gender, the NT-proBNP level after exercise in 3 hours, left atrial volume index before exercise, right ventricular systolic pressure before exercise, E velocity after exercise, and E/e' ratio after exercise varied significantly. In addition, peak VO 2 was inversely related to NT-proBNP before (r = -0.352, p <0.001) and after exercise (r = -0.351, p <0.001). The NT-proBNP level before exercise was directly related to the left atrial volume index, E/e' ratio, and right ventricular systolic pressure before and after exercise. NT-proBNP after exercise was also directly related to the same parameters. NT-proBNP levels both before and after exercise were higher in the group with lower exercise tolerance. In conclusion, through the correlation among exercise tolerance, NT-proBNP, and parameters of diastolic dysfunction, we demonstrated that diastolic dysfunction and NT-proBNP could predict exercise tolerance in patients with significant VHD and normal LV EF. Copyright © 2017 Elsevier Inc. All rights reserved.

Nonlinear and Stochastic Dynamics in the Heart

PubMed Central

Qu, Zhilin; Hu, Gang; Garfinkel, Alan; Weiss, James N.

2014-01-01

In a normal human life span, the heart beats about 2 to 3 billion times. Under diseased conditions, a heart may lose its normal rhythm and degenerate suddenly into much faster and irregular rhythms, called arrhythmias, which may lead to sudden death. The transition from a normal rhythm to an arrhythmia is a transition from regular electrical wave conduction to irregular or turbulent wave conduction in the heart, and thus this medical problem is also a problem of physics and mathematics. In the last century, clinical, experimental, and theoretical studies have shown that dynamical theories play fundamental roles in understanding the mechanisms of the genesis of the normal heart rhythm as well as lethal arrhythmias. In this article, we summarize in detail the nonlinear and stochastic dynamics occurring in the heart and their links to normal cardiac functions and arrhythmias, providing a holistic view through integrating dynamics from the molecular (microscopic) scale, to the organelle (mesoscopic) scale, to the cellular, tissue, and organ (macroscopic) scales. We discuss what existing problems and challenges are waiting to be solved and how multi-scale mathematical modeling and nonlinear dynamics may be helpful for solving these problems. PMID:25267872

Bifunctional staining for ex vivo determination of area at risk in rabbits with reperfused myocardial infarction

PubMed Central

Feng, Yuanbo; Ma, Zhan-Long; Chen, Feng; Yu, Jie; Cona, Marlein Miranda; Xie, Yi; Li, Yue; Ni, Yicheng

2013-01-01

AIM: To develop a method for studying myocardial area at risk (AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging (cMRI). METHODS: Nine rabbits were anesthetized, intubated and subjected to occlusion and reperfusion of the left circumflex coronary artery (LCx) to induce myocardial infarction (MI). ECG-triggered cMRI with delayed enhancement was performed at 3.0 T. After euthanasia, the heart was excised with the LCx re-ligated. Bifunctional staining was performed by perfusing the aorta with a homemade red-iodized-oil (RIO) dye. The heart was then agar-embedded for ex vivo magnetic resonance imaging and sliced into 3 mm-sections. The AAR was defined by RIO-staining and digital radiography (DR). The perfusion density rate (PDR) was derived from DR for the AAR and normal myocardium. The MI was measured by in vivo delayed enhancement (iDE) and ex vivo delayed enhancement (eDE) cMRI. The AAR and MI were compared to validate the bifunctional straining for cardiac imaging research. Linear regression with Bland-Altman agreement, one way-ANOVA with Bonferroni’s multiple comparison, and paired t tests were applied for statistics. RESULTS: All rabbits tolerated well the surgical procedure and subsequent cMRI sessions. The open-chest occlusion and close-chest reperfusion of the LCx, double suture method and bifunctional staining were successfully applied in all animals. The percentage MI volumes globally (n = 6) and by slice (n = 25) were 36.59% ± 13.68% and 32.88% ± 12.38% on iDE, and 35.41% ± 12.25% and 32.40% ± 12.34% on eDE. There were no significant differences for MI determination with excellent linear regression correspondence (rglobal = 0.89; rslice = 0.9) between iDE and eDE. The percentage AAR volumes globally (n = 6) and by slice (n = 25) were 44.82% ± 15.18% and 40.04% ± 13.64% with RIO-staining, and 44.74% ± 15.98% and 40.48% ± 13.26% by DR showing high correlation in linear regression analysis (rglobal = 0.99; rslice = 1.0). The mean differences of the two AAR measurements on Bland-Altman were almost zero, indicating RIO-staining and DR were essentially equivalent or inter-replaceable. The AAR was significantly larger than MI both globally and slice-by-slice (P < 0.01). After correction with the background and the blank heart without bifunctional staining (n = 3), the PDR for the AAR and normal myocardium was 32% ± 15% and 35.5% ± 35%, respectively, which is significantly different (P < 0.001), suggesting that blood perfusion to the AAR probably by collateral circulation was only less than 10% of that in the normal myocardium. CONCLUSION: The myocardial area at risk in ischemic heart disease could be accurately determined postmortem by this novel bifunctional staining, which may substantially contribute to translational cardiac imaging research. PMID:25237621

Obesity depresses baroreflex control of renal sympathetic nerve activity and heart rate in Sprague Dawley rats: role of the renal innervation.

PubMed

Khan, S A; Sattar, M Z A; Abdullah, N A; Rathore, H A; Abdulla, M H; Ahmad, A; Johns, E J

2015-07-01

This study investigated the role of the renal innervation in arterial and cardiopulmonary baroreflex regulation of renal sympathetic nerve activity (RSNA) and heart rate (HR) in rats fed a high-fat diet to induce obesity. Rats received either a normal (12% kcal) or high (45% kcal) fat diet for 60 days. On day 61, rats were anesthetized and prepared for recording left RSNA. In one group, the renal nerves remained intact, while in the other, both kidneys were denervated. Baroreflex gain curves for RSNA and HR were generated by increasing and decreasing blood pressure. Low-pressure baroreceptors were challenged by infusing a saline load. Mean blood pressure was 135 mmHg in the fat-fed and 105 mmHg (P < 0.05) in normal rats. Weight gain, adiposity index and creatinine clearance were 37, 82 and 55% higher (P < 0.05-0.001), but urine flow rate and fractional sodium excretions were 53 and 65% (both P < 0.001) lower, respectively, in the fat-fed compared to normal rats. In fat-fed rats with innervated kidneys, RSNA and HR arterial baroreflex sensitivities were reduced by 73 and 72% (both P < 0.05) but were normal in renally denervated rats. Volume expansion decreased RSNA by 66% (P < 0.001) in normal rats, but not in the intact fat-fed rats and by 51% (P < 0.01) in renally denervated fat-fed rats. Feeding a high-fat diet caused hypertension associated with dysregulation of the arterial and cardiopulmonary baroreflexes which was dependent on an intact renal innervation. This suggests that in obese states neural signals arising from the kidney contribute to a deranged autonomic control. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

4D CT-based Treatment Planning for Intensity-Modulated Radiation Therapy and Proton Therapy for Distal Esophagus Cancer

PubMed Central

Zhang, Xiaodong; Zhao, Kuai-Le; Guerrero, Thomas M.; McGuire, Sean E.; Yaremko, Brian; Komaki, Ritsuko; Cox, James D.; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D.; Mohan, Radhe; Liao, Zhongxing

2008-01-01

Purpose To compare three-dimensional (3D) and 4D computed tomography (CT)– based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. Materials and Methods IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Results Compared with IMRT, median lung volumes exposed to 5,10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%,5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%,8.4%,5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index CI=1.99) and greater irradiation of the heart (heart-V40=41.8%) compared with the IMRT plan(CI=1.55, heart-V40=35.7%) or the three-beam proton plan (CI=1.46, heart-V40=27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas-filling. Conclusions Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses. PMID:18722278

Four-dimensional computed tomography-based treatment planning for intensity-modulated radiation therapy and proton therapy for distal esophageal cancer.

PubMed

Zhang, Xiaodong; Zhao, Kuai-le; Guerrero, Thomas M; McGuire, Sean E; Yaremko, Brian; Komaki, Ritsuko; Cox, James D; Hui, Zhouguang; Li, Yupeng; Newhauser, Wayne D; Mohan, Radhe; Liao, Zhongxing

2008-09-01

To compare three-dimensional (3D) and four-dimensional (4D) computed tomography (CT)-based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. The IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Compared with IMRT, median lung volumes exposed to 5, 10, and 20 Gy and mean lung dose were reduced by 35.6%, 20.5%, 5.8%, and 5.1 Gy for a two-beam proton plan and by 17.4%, 8.4%, 5%, and 2.9 Gy for a three-beam proton plan. The greater lung sparing in the two-beam proton plan was achieved at the expense of less conformity to the target (conformity index [CI], 1.99) and greater irradiation of the heart (heart-V40, 41.8%) compared with the IMRT plan(CI, 1.55, heart-V40, 35.7%) or the three-beam proton plan (CI, 1.46, heart-V40, 27.7%). Target coverage differed by more than 2% between the 3D and 4D plans for patients with substantial diaphragm motion in the three-beam proton and IMRT plans. The difference in spinal cord maximum dose between 3D and 4D plans could exceed 5 Gy for the proton plans partly owing to variations in stomach gas filling. Proton therapy provided significantly better sparing of lung than did IMRT. Diaphragm motion and stomach gas-filling must be considered in evaluating target coverage and cord doses.

Limiting the risk of cardiac toxicity with esophageal-sparing intensity modulated radiotherapy for locally advanced lung cancers.

PubMed

Woodford, Katrina; Panettieri, Vanessa; Ruben, Jeremy D; Senthi, Sashendra

2016-05-01

Intensity modulated radiotherapy (IMRT) is routinely utilized in the treatment of locally advanced non-small cell lung cancer (NSCLC). RTOG 0617 found that overall survival was impacted by increased low (5 Gy) and intermediate (30 Gy) cardiac doses. We evaluated the impact of esophageal-sparing IMRT on cardiac doses with and without the heart considered in the planning process and predicted toxicity compared to 3D-conventional radiotherapy (3DCRT). Ten consecutive patients with N2 Stage III NSCLC treated to 60 Gy in 30 fractions, between February 2012 and September 2014, were evaluated. For each patient, 3DCRT and esophageal-sparing IMRT plans were generated. IMRT plans were then created with and without the heart considered in the optimization process. To compare plans, the dose delivered to 95% and 99% of the target (D95% and D99%), and doses to the esophagus, lung and heart were compared by determining the volume receiving X dose (VXGy) and the normal tissue complication probability (NTCP) calculated. IMRT reduced maximum esophagus dose to below 60 Gy in all patients and produced significant reductions to V50Gy, V40Gy and esophageal NTCP. The cost of this reduction was a non-statistically, non-clinically significant increase in low dose (5 Gy) lung exposure that did not worsen lung NTCP. IMRT plans produced significant cardiac sparing, with the amount of improvement correlating to the amount of heart overlapping with the target. When included in plan optimization, for selected patients further sparing of the heart and improvement in heart NTCP was possible. Esophageal-sparing IMRT can significantly spare the heart even if it is not considered in the optimization process. Further sparing can be achieved if plan optimization constrains low and intermediate heart doses, without compromising lung doses.

3D Finite Element Electrical Model of Larval Zebrafish ECG Signals

PubMed Central

Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

2016-01-01

Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions. PMID:27824910

Inhibition of soluble epoxide hydrolase does not improve the course of congestive heart failure and the development of renal dysfunction in rats with volume overload induced by aorto-caval fistula

PubMed Central

Červenka, Luděk; Melenovský, Vojtěch; Husková, Zuzana; Sporková, Alexandra; Bürgelová, Marcela; Škaroupková, Petra; Hwang, Sung Hee; Hammock, Bruce D.; Imig, John D.; Sadowski, Janusz

2016-01-01

The detailed mechanisms determining the course of congestive heart failure (CHF) and associated renal dysfunction remain unclear. In a volume overload model of CHF induced by creation of aorto-caval fistula (ACF) in Hannover Sprague-Dawley (HanSD) rats we explored the putative pathogenetic contribution of epoxyeicosatrienoic acids (EETs), active products of CYP-450 dependent epoxygenase pathway of arachidonic acid metabolism, and compared it with the role of the renin-angiotensin system (RAS). Chronic treatment with cis-4-[4-(3-adamantan-1-yl-ureido) cyclohexyloxy]benzoic acid (c-AUCB, 3 mg/L in drinking water), an inhibitor of soluble epoxide hydrolase (sEH) which normally degrades EETs, increased intrarenal and myocardial EETs to levels observed in sham-operated HanSD rats, but did not improve the survival or renal function impairment. In contrast, chronic angiotensin-converting enzyme inhibition (ACEi, trandolapril, 6 mg/L in drinking water) increased renal blood flow, fractional sodium excretion and markedly improved survival, without affecting left ventricular structure and performance. Hence, renal dysfunction rather than cardiac remodeling determines long-term mortality in advanced stage of CHF due to volume overload. Strong protective actions of ACEi were associated with suppression of the vasoconstrictor/sodium retaining axis and activation of vasodilatory/natriuretic axis of the renin-angiotensin system in the circulating blood and kidney tissue. PMID:26047375

Structural Integrity of Normal Appearing White Matter and Sex-Specific Outcomes After Acute Ischemic Stroke.

PubMed

Etherton, Mark R; Wu, Ona; Cougo, Pedro; Giese, Anne-Katrin; Cloonan, Lisa; Fitzpatrick, Kaitlin M; Kanakis, Allison S; Boulouis, Gregoire; Karadeli, Hasan H; Lauer, Arne; Rosand, Jonathan; Furie, Karen L; Rost, Natalia S

2017-12-01

Women have worse poststroke outcomes than men. We evaluated sex-specific clinical and neuroimaging characteristics of white matter in association with functional recovery after acute ischemic stroke. We performed a retrospective analysis of acute ischemic stroke patients with admission brain MRI and 3- to 6-month modified Rankin Scale score. White matter hyperintensity and acute infarct volume were quantified on fluid-attenuated inversion recovery and diffusion tensor imaging MRI, respectively. Diffusivity anisotropy metrics were calculated in normal appearing white matter contralateral to the acute ischemia. Among 319 patients with acute ischemic stroke, women were older (68.0 versus 62.7 years; P =0.004), had increased incidence of atrial fibrillation (21.4% versus 12.2%; P =0.04), and lower rate of tobacco use (21.1% versus 35.9%; P =0.03). There was no sex-specific difference in white matter hyperintensity volume, acute infarct volume, National Institutes of Health Stroke Scale, prestroke modified Rankin Scale score, or normal appearing white matter diffusivity anisotropy metrics. However, women were less likely to have an excellent outcome (modified Rankin Scale score <2: 49.6% versus 67.0%; P =0.005). In logistic regression analysis, female sex and the interaction of sex with fractional anisotropy, radial diffusivity, and axial diffusivity were independent predictors of functional outcome. Female sex is associated with decreased likelihood of excellent outcome after acute ischemic stroke. The correlation between markers of white matter integrity and functional outcomes in women, but not men, suggests a potential sex-specific mechanism. © 2017 American Heart Association, Inc.

Heart rate variability in normal-weight patients with polycystic ovary syndrome.

PubMed

Kilit, Celal; Paşalı Kilit, Türkan

2017-05-01

Polycystic ovary syndrome (PCOS) is an endocrine disease closely related to several risk factors of cardiovascular disease. Obese women with PCOS show altered autonomic modulation. The results of studies investigating cardiac autonomic functions of normal-weight women with PCOS are conflicting. The aim of the study was to assess the reactivity of cardiac sympathovagal balance in normal-weight women with PCOS by heart rate variability analysis. We examined the heart rate variability in 60 normal-weight women with PCOS and compared them with that in 60 age-matched healthy women having a similar metabolic profile. Time and frequency domain parameters of heart rate variability were analyzed based on 5-min-long continuous electrocardiography recordings for the following 3 periods: (1) during rest in supine position, (2) during controlled breathing, and (3) during isometric handgrip exercise. Time and frequency domain parameters of heart rate variability for the 3 periods assessed were similar in the two groups. Although modified Ferriman-Gallwey score and serum testosterone and luteinizing hormone levels were significantly higher in women with PCOS, homeostatic model assessment-insulin resistance (HOMA-IR) was not different the between the PCOS and control groups. There were no significant correlations between serum testosterone levels and heart rate variability parameters among the study population. The findings of this study suggest that the reactivity of cardiac sympathovagal balance is not altered in normal-weight women with PCOS having a normal HOMA-IR.

Increased Regional Epicardial Fat Volume Associated with Reversible Myocardial Ischemia in Patients with Suspected Coronary Artery Disease

PubMed Central

Khawaja, Tuba; Greer, Christine; Thadani, Samir R.; Kato, Tomoko S.; Bhatia, Ketan; Shimbo, Daichi; Konkak, Andrew; Bokhari, Sabahat; Einstein, Andrew J.; Schulze, P. Christian

2015-01-01

Epicardial adipose tissue is a source of pro-inflammatory cytokines and has been linked to the development of coronary artery disease. No study has systematically assessed the relationship between local epicardial fat volume (EFV) and myocardial perfusion defects. We analyzed EFV in patients undergoing SPECT myocardial perfusion imaging combined with computed tomography (CT) for attenuation correction. Low-dose CT without contrast was performed in 396 consecutive patients undergoing SPECT imaging for evaluation of coronary artery disease. Regional thickness, cross-sectional areas, and total EFV were assessed. 295 patients had normal myocardial perfusion scans and 101 had abnormal perfusion scans. Mean EFVs in normal, ischemic, and infarcted hearts were 99.8 ± 82.3 cm3, 156.4 ± 121.9 cm3, and 96.3 ± 102.1 cm3, respectively (P < 0.001). Reversible perfusion defects were associated with increased local EFV compared to normal perfusion in the distribution of the right (69.2 ± 51.5 vs 46.6 ± 32.0 cm3; P = 0.03) and left anterior descending coronary artery (87.1 ± 76.4 vs 46.7 ± 40.6 cm3; P = 0.005). Our results demonstrate increased regional epicardial fat in patients with active myocardial ischemia compared to patients with myocardial scar or normal perfusion on nuclear perfusion scans. Our results suggest a potential role for cardiac CT to improve risk stratification in patients with suspected coronary artery disease. PMID:25339129

Reduced left ventricular filling following blood volume extraction does not result in compensatory augmentation of cardiac mechanics.

PubMed

Lord, Rachel; MacLeod, David; George, Keith; Oxborough, David; Shave, Rob; Stembridge, Mike

2018-04-01

What is the central question of this study? A reduction in left ventricular (LV) filling, and concomitant increase in heart rate, augments LV mechanics to maintain stroke volume (SV); however, the impact of reduced LV filling in isolation on SV and LV mechanics is currently unknown. What is the main finding and its importance? An isolated decrease in LV filling did not provoke a compensatory increase in mechanics to maintain SV; in contrast, LV mechanics and SV were reduced. These data indicate that when LV filling is reduced without changes in heart rate, LV mechanics do not compensate to maintain SV. An acute non-invasive reduction in preload has been shown to augment cardiac mechanics to maintain stroke volume and cardiac output. Such interventions induce concomitant changes in heart rate, whereas blood volume extraction reduces preload without changes in heart rate. Therefore, the purpose of this study was to determine whether a preload reduction in isolation resulted in augmented stroke volume achieved via enhanced cardiac mechanics. Nine healthy volunteers (four female, age 29 ± 11 years) underwent echocardiography for the assessment of left ventricular (LV) volumes and mechanics in a supine position at baseline and end extraction after the controlled removal of 25% of total blood volume (1062 ± 342 ml). Arterial blood pressure was monitored continuously by a pressure transducer attached to an indwelling radial artery catheter. Heart rate and total peripheral resistance were unchanged from baseline to end extraction, but systolic blood pressure was reduced (from 148 to 127 mmHg). From baseline to end extraction there were significant reductions in left ventricular end-diastolic volume (from 89 to 71 ml) and stroke volume (from 56 to 37 ml); however, there was no change in LV twist, basal or apical rotation. In contrast, LV longitudinal strain (from -20 to -17%) and basal circumferential strain (from -22 to -19%) were significantly reduced from baseline to end extraction. In conclusion, a reduction in preload during blood volume extraction does not result in compensatory changes in stroke volume or cardiac mechanics. Our data suggest that LV strain is dependent on LV filling and consequent geometry, whereas LV twist could be mediated by heart rate. © 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.

Is the normal heart rate ``chaotic'' due to respiration?

NASA Astrophysics Data System (ADS)

Wessel, Niels; Riedl, Maik; Kurths, Jürgen

2009-06-01

The incidence of cardiovascular diseases increases with the growth of the human population and an aging society, leading to very high expenses in the public health system. Therefore, it is challenging to develop sophisticated methods in order to improve medical diagnostics. The question whether the normal heart rate is chaotic or not is an attempt to elucidate the underlying mechanisms of cardiovascular dynamics and therefore a highly controversial topical challenge. In this contribution we demonstrate that linear and nonlinear parameters allow us to separate completely the data sets of the three groups provided for this controversial topic in nonlinear dynamics. The question whether these time series are chaotic or not cannot be answered satisfactorily without investigating the underlying mechanisms leading to them. We give an example of the dominant influence of respiration on heart beat dynamics, which shows that observed fluctuations can be mostly explained by respiratory modulations of heart rate and blood pressure (coefficient of determination: 96%). Therefore, we recommend reformulating the following initial question: "Is the normal heart rate chaotic?" We rather ask the following: "Is the normal heart rate `chaotic' due to respiration?"

Biomechanics of Cardiac Function

PubMed Central

Voorhees, Andrew P.; Han, Hai-Chao

2015-01-01

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments. PMID:26426462

Exercise cardiac output following Skylab missions - The second manned Skylab mission

NASA Technical Reports Server (NTRS)

Buderer, M. C.; Mauldin, D. G.; Rummel, J. A.; Michel, E. L.; Sawin, C. F.

1976-01-01

Cardiac output was measured during preflight and postflight exercise-stress tests on the Skylab astronauts. In the postflight tests immediately following the 28-, 59-, and 84-d earth orbital missions, the astronauts exhibited an approximate 30% decrease in cardiac output coupled with an approximate 50% decrease in cardiac stroke volume during exercise. These changes were accompanied by elevated heart rates and significant increases in total systemic peripheral vascular resistance. Mean arterial pressure was unchanged. All parameters returned to normal preflight values within 30 d of the end of the orbital period. Duration of the zero-G exposure did not appear to influence either the magnitude of the hemodynamic changes or the time-course of their return to normal. These results are discussed in relation to other cardiovascular findings and possible mechanisms responsible for the observations are outlined.

Idiopathic restrictive cardiomyopathy is part of the clinical expression of cardiac troponin I mutations

PubMed Central

Mogensen, Jens; Kubo, Toru; Duque, Mauricio; Uribe, William; Shaw, Anthony; Murphy, Ross; Gimeno, Juan R.; Elliott, Perry; McKenna, William J.

2003-01-01

Restrictive cardiomyopathy (RCM) is an uncommon heart muscle disorder characterized by impaired filling of the ventricles with reduced volume in the presence of normal or near normal wall thickness and systolic function. The disease may be associated with systemic disease but is most often idiopathic. We recognized a large family in which individuals were affected by either idiopathic RCM or hypertrophic cardiomyopathy (HCM). Linkage analysis to selected sarcomeric contractile protein genes identified cardiac troponin I (TNNI3) as the likely disease gene. Subsequent mutation analysis revealed a novel missense mutation, which cosegregated with the disease in the family (lod score: 4.8). To determine if idiopathic RCM is part of the clinical expression of TNNI3 mutations, genetic investigations of the gene were performed in an additional nine unrelated RCM patients with restrictive filling patterns, bi-atrial dilatation, normal systolic function, and normal wall thickness. TNNI3 mutations were identified in six of these nine RCM patients. Two of the mutations identified in young individuals were de novo mutations. All mutations appeared in conserved and functionally important domains of the gene. PMID:12531876

Evaluation and management of bradycardia in neonates and children.

PubMed

Baruteau, Alban-Elouen; Perry, James C; Sanatani, Shubhayan; Horie, Minoru; Dubin, Anne M

2016-02-01

Heart rate is commonly used in pediatric early warning scores. Age-related changes in the anatomy and physiology of infants and children produce normal ranges for electrocardiogram features that differ from adults and vary with age. Bradycardia is defined as a heart rate below the lowest normal value for age. Pediatric bradycardia most commonly manifests as sinus bradycardia, junctional bradycardia, or atrioventricular block. As a result of several different etiologies, it may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited sinus node dysfunction or progressive cardiac conduction disorders. Management and eventual prognosis of bradycardia in the young are entirely dependent upon the underlying cause. Reasons to intervene for bradycardia are the association of related symptoms and/or the downstream risk of heart failure or pause-dependent tachyarrhythmia. The simplest aspect of severe bradycardia management is reflected in the Pediatric and Advanced Life Support (PALS) guidelines. Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current practice for evaluation and management of bradycardia in neonates and children. Bradycardia is defined as a heart rate below the lowest normal value for age. Age related changes in the anatomy and physiology of infants and children produce normal ranges for electrocardiogram features that differ from adults and vary with age. Pediatric bradycardia most commonly manifests as sinus bradycardia, junctional bradycardia, or atrioventricular block. Management and eventual prognosis of bradycardia in the young are entirely dependent upon the underlying cause. Bradycardia may occur in a structurally normal heart or in association with congenital heart disease. Genetic variants in multiple genes have been described. Reasons to intervene for bradycardia are the association of related symptoms and/or the downstream risk of heart failure or pause-dependent tachyarrhythmia. Early diagnosis and appropriate management are critical in order to prevent sudden death.

The heart of the matter: from guided microtools to 3-D printing and precision genome editing, promising research could lead to new advances in pediatric cardiology.

PubMed

Chandler, David L

2015-01-01

The smooth, powerful muscles of a newborn baby?s heart are pulsing normally, squeezing in and letting go rhythmically as a 3-mm-wide catheter-like tube snakes its way through, entering via an artery and being guided slowly by a surgeon. When it reaches its target?a protruding knot of malformed muscle tissue within a ventricle that has been partly blocking the valve?the tip of the precisely controlled tube whirs into action, with tiny scissor-like rotating blades gently grinding up the excess tissue as those pieces are sucked back into the device, leaving no floating particles that could lead to a blockage elsewhere. The defect is fully removed, and the heart?s function is restored to normal, leaving the child with the prospect of a normal life. The whole minimally invasive process takes place inside a beating heart and would otherwise have required open-heart surgery, with the heart stopped for a cardiopulmonary bypass.

Comparison at Necropsy of Heart Weight in Women Aged 20 to 29 Years With Fatal Trauma or Chemical Intoxication Versus Fatal Natural Cause (A Search for the Normal Adult Heart Weight).

PubMed

Blackbourne, Brian D; Vasudevan, Anupama; Roberts, William C

2017-03-01

The present obesity epidemic makes determining the normal heart weight in adults difficult. This study examines the heart weight at autopsy in 104 women aged 20 to 29 years who died in 1978 to 1980 before the overweight epidemic ensued. Of the 104 cases, the hearts weighed ≤300 g in 86 (83%) and >300 g in 18 (17%). Of the 67 cases dying from an unnatural cause (trauma or chemical intoxication), only 3 (4%) had hearts weighing >300 g; of the 37 patients dying from a variety of natural causes, 15 (41%) had hearts weighing >300 g (p <0.001). The body mass index (BMI) was ≤25 kg/m 2 in 82 cases (79%) and the hearts in them ranged from 120 to 400 g (mean 262 ± 51; median 257 g); of the 22 cases (21%) in whom the BMI was >25 kg/m 2 , the hearts ranged from 230 to 850 g (mean 351 ± 142; median 300 g). In conclusion, the cases dying from an unnatural cause had smaller mean heart weights than those women dying from a natural cause and those with a normal BMI (≤25 kg/m 2 ) had smaller mean heart weights than those with a BMI >25 kg/m 2 . The normal heart weight in young women dying from an unnatural cause with few exceptions is <300 g. Copyright © 2016 Elsevier Inc. All rights reserved.

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

[Analysis of the heart sound with arrhythmia based on nonlinear chaos theory].

PubMed

Ding, Xiaorong; Guo, Xingming; Zhong, Lisha; Xiao, Shouzhong

2012-10-01

In this paper, a new method based on the nonlinear chaos theory was proposed to study the arrhythmia with the combination of the correlation dimension and largest Lyapunov exponent, through computing and analyzing these two parameters of 30 cases normal heart sound and 30 cases with arrhythmia. The results showed that the two parameters of the heart sounds with arrhythmia were higher than those with the normal, and there was significant difference between these two kinds of heart sounds. That is probably due to the irregularity of the arrhythmia which causes the decrease of predictability, and it's more complex than the normal heart sound. Therefore, the correlation dimension and the largest Lyapunov exponent can be used to analyze the arrhythmia and for its feature extraction.

RBC indices

MedlinePlus

... sudden blood loss, long-term diseases, kidney failure , aplastic anemia , or man-made heart valves). MCV above normal. ... sudden blood loss, long-term diseases, kidney failure, aplastic anemia, or man-made heart valves). MCH above normal. ...

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.

Consequences of additional use of PET information for target volume delineation and radiotherapy dose distribution for esophageal cancer.

PubMed

Muijs, Christina T; Schreurs, Liesbeth M; Busz, Dianne M; Beukema, Jannet C; van der Borden, Arnout J; Pruim, Jan; Van der Jagt, Eric J; Plukker, John Th; Langendijk, Johannes A

2009-12-01

To determine the consequences of target volume (TV) modifications, based on the additional use of PET information, on radiation planning, assuming PET/CT-imaging represents the true extent of the tumour. For 21 patients with esophageal cancer, two separate TV's were retrospectively defined based on CT (CT-TV) and co-registered PET/CT images (PET/CT-TV). Two 3D-CRT plans (prescribed dose 50.4 Gy) were constructed to cover the corresponding TV's. Subsequently, these plans were compared for target coverage, normal tissue dose-volume histograms and the corresponding normal tissue complication probability (NTCP) values. The addition of PET led to the modification of CT-TV with at least 10% in 12 of 21 patients (57%) (reduction in 9, enlargement in 3). PET/CT-TV was inadequately covered by the CT-based treatment plan in 8 patients (36%). Treatment plan modifications resulted in significant changes (p<0.05) in dose distributions to heart and lungs. Corresponding changes in NTCP values ranged from -3% to +2% for radiation pneumonitis and from -0.2% to +1.2% for cardiac mortality. This study demonstrated that TV's based on CT might exclude PET-avid disease. Consequences are under dosing and thereby possibly ineffective treatment. Moreover, the addition of PET in radiation planning might result in clinical important changes in NTCP.

Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans.

PubMed

Cui, Jian; McQuillan, Patrick M; Blaha, Cheryl; Kunselman, Allen R; Sinoway, Lawrence I

2012-08-15

We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P < 0.01) and more sustained MSNA and blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects.

A modified Glenn shunt reduces venous congestion during acute right ventricular failure due to pulmonary banding: a randomized experimental study

PubMed Central

Vikholm, Per; Schiller, Petter; Hellgren, Laila

2014-01-01

OBJECTIVES Right ventricular failure after left ventricular assist device implantation is a serious complication with high rates of mortality and morbidity. It has been demonstrated in experimental settings that volume exclusion of the right ventricle with a modified Glenn shunt can improve haemodynamics during ischaemic right ventricular failure. However, the concept of a modified Glenn shunt is dependent on a normal pulmonary vascular resistance, which can limit its use in some patients. The aim of this study was to explore the effects of volume exclusion with a modified Glenn shunt during right ventricular failure due to pulmonary banding, and to study the alterations in genetic expression in the right ventricle due to pressure and volume overload. METHODS Experimental right ventricular failure was induced in pigs (n = 11) through 2 h of pulmonary banding. The pigs were randomized to either treatment with a modified Glenn shunt and pulmonary banding (n = 6) or solely pulmonary banding (n = 5) as a control group. Haemodynamic measurements, blood samples and right ventricular biopsies for genetic analysis were sampled at baseline, at right ventricular failure (i.e. 2 h of pulmonary banding) and 1 h post-right ventricular failure in both groups. RESULTS Right atrial pressure increased from 10 mmHg (9.0–12) to 18 mmHg (16–22) (P < 0.01) and the right ventricular pressure from 31 mmHg (26–35) to 57 mmHg (49–61) (P < 0.01) after pulmonary banding. Subsequent treatment with the modified Glenn shunt resulted in a decrease in right atrial pressure to 13 mmHg (11–14) (P = 0.03). In the control group, right atrial pressure was unchanged at 19 mmHg (16–20) (P = 0.18). At right heart failure, there was an up-regulation of genes associated with heart failure, inflammation, angiogenesis, negative regulation of cell death and proliferation. CONCLUSIONS Volume exclusion with a modified Glenn shunt during right ventricular failure reduced venous congestion compared with the control group. The state of right heart failure was verified through genetic expressional changes. PMID:24396048

Computational prediction of the effects of the intra-aortic balloon pump on heart failure with valvular regurgitation using a 3D cardiac electromechanical model.

PubMed

Kim, Chang-Hyun; Song, Kwang-Soup; Trayanova, Natalia A; Lim, Ki Moo

2018-05-01

Intra-aortic balloon pump (IABP) is normally contraindicated in significant aortic regurgitation (AR). It causes and aggravates pre-existing AR while performing well in the event of mitral regurgitation (MR). Indirect parameters, such as the mean systolic pressure, product of heart rate and peak systolic pressure, and pressure-volume are used to quantify the effect of IABP on ventricular workload. However, to date, no studies have directly quantified the reduction in workload with IABP. The goal of this study is to examine the effect of IABP therapy on ventricular mechanics under valvular insufficiency by using a computational model of the heart. For this purpose, the 3D electromechanical model of the failing ventricles used in previous studies was coupled with a lumped parameter model of valvular regurgitation and the IABP-treated vascular system. The IABP therapy was disturbed in terms of reducing the myocardial tension generation and contractile ATP consumption by valvular regurgitation, particularly in the AR condition. The IABP worsened the problem of ventricular expansion induced as a result of the regurgitated blood volume during the diastole under the AR condition. The IABP reduced the LV stroke work in the AR, MR, and no regurgitation conditions. Therefore, the IABP helped the ventricle to pump blood and reduced the ventricular workload. In conclusion, the IABP partially performed its role in the MR condition. However, it was disturbed by the AR and worsened the cardiovascular responses that followed the AR. Therefore, this study computationally proved the reason for the clinical contraindication of IABP in AR patients.

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

Normal values and standardization of parameters in nuclear cardiology: Japanese Society of Nuclear Medicine working group database.

PubMed

Nakajima, Kenichi; Matsumoto, Naoya; Kasai, Tokuo; Matsuo, Shinro; Kiso, Keisuke; Okuda, Koichi

2016-04-01

As a 2-year project of the Japanese Society of Nuclear Medicine working group activity, normal myocardial imaging databases were accumulated and summarized. Stress-rest with gated and non-gated image sets were accumulated for myocardial perfusion imaging and could be used for perfusion defect scoring and normal left ventricular (LV) function analysis. For single-photon emission computed tomography (SPECT) with multi-focal collimator design, databases of supine and prone positions and computed tomography (CT)-based attenuation correction were created. The CT-based correction provided similar perfusion patterns between genders. In phase analysis of gated myocardial perfusion SPECT, a new approach for analyzing dyssynchrony, normal ranges of parameters for phase bandwidth, standard deviation and entropy were determined in four software programs. Although the results were not interchangeable, dependency on gender, ejection fraction and volumes were common characteristics of these parameters. Standardization of (123)I-MIBG sympathetic imaging was performed regarding heart-to-mediastinum ratio (HMR) using a calibration phantom method. The HMRs from any collimator types could be converted to the value with medium-energy comparable collimators. Appropriate quantification based on common normal databases and standard technology could play a pivotal role for clinical practice and researches.

Saxagliptin and Tadalafil Differentially Alter Cyclic Guanosine Monophosphate (cGMP) Signaling and Left Ventricular Function in Aortic-Banded Mini-Swine.

PubMed

Hiemstra, Jessica A; Lee, Dong I; Chakir, Khalid; Gutiérrez-Aguilar, Manuel; Marshall, Kurt D; Zgoda, Pamela J; Cruz Rivera, Noelany; Dozier, Daniel G; Ferguson, Brian S; Heublein, Denise M; Burnett, John C; Scherf, Carolin; Ivey, Jan R; Minervini, Gianmaria; McDonald, Kerry S; Baines, Christopher P; Krenz, Maike; Domeier, Timothy L; Emter, Craig A

2016-04-20

Cyclic guanosine monophosphate-protein kinase G-phosphodiesterase 5 signaling may be disturbed in heart failure (HF) with preserved ejection fraction, contributing to cardiac remodeling and dysfunction. The purpose of this study was to manipulate cyclic guanosine monophosphate signaling using the dipeptidyl-peptidase 4 inhibitor saxagliptin and phosphodiesterase 5 inhibitor tadalafil. We hypothesized that preservation of cyclic guanosine monophosphate cGMP signaling would attenuate pathological cardiac remodeling and improve left ventricular (LV) function. We assessed LV hypertrophy and function at the organ and cellular level in aortic-banded pigs. Concentric hypertrophy was equal in all groups, but LV collagen deposition was increased in only HF animals. Prevention of fibrotic remodeling by saxagliptin and tadalafil was correlated with neuropeptide Y plasma levels. Saxagliptin better preserved integrated LV systolic and diastolic function by maintaining normal LV chamber volumes and contractility (end-systolic pressure-volume relationship, preload recruitable SW) while preventing changes to early/late diastolic longitudinal strain rate. Function was similar to the HF group in tadalafil-treated animals including increased LV contractility, reduced chamber volume, and decreased longitudinal, circumferential, and radial mechanics. Saxagliptin and tadalafil prevented a negative cardiomyocyte shortening-frequency relationship observed in HF animals. Saxagliptin increased phosphodiesterase 5 activity while tadalafil increased cyclic guanosine monophosphate levels; however, neither drug increased downstream PKG activity. Early mitochondrial dysfunction, evident as decreased calcium-retention capacity and Complex II-dependent respiratory control, was present in both HF and tadalafil-treated animals. Both saxagliptin and tadalafil prevented increased LV collagen deposition in a manner related to the attenuation of increased plasma neuropeptide Y levels. Saxagliptin appears superior for treating heart failure with preserved ejection fraction, considering its comprehensive effects on integrated LV systolic and diastolic function. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Using a whole-body 31P birdcage transmit coil and 16-element receive array for human cardiac metabolic imaging at 7T

PubMed Central

Dragonu, Iulius; Almujayyaz, Salam; Batzakis, Alex; Young, Liam A. J.; Purvis, Lucian A. B.; Clarke, William T.; Wichmann, Tobias; Lanz, Titus; Neubauer, Stefan; Robson, Matthew D.; Klomp, Dennis W. J.; Rodgers, Christopher T.

2017-01-01

Purpose Cardiac phosphorus magnetic resonance spectroscopy (31P-MRS) provides unique insight into the mechanisms of heart failure. Yet, clinical applications have been hindered by the restricted sensitivity of the surface radiofrequency-coils normally used. These permit the analysis of spectra only from the interventricular septum, or large volumes of myocardium, which may not be meaningful in focal disease. Löring et al. recently presented a prototype whole-body (52 cm diameter) transmit/receive birdcage coil for 31P at 7T. We now present a new, easily-removable, whole-body 31P transmit radiofrequency-coil built into a patient-bed extension combined with a 16-element receive array for cardiac 31P-MRS. Materials and methods A fully-removable (55 cm diameter) birdcage transmit coil was combined with a 16-element receive array on a Magnetom 7T scanner (Siemens, Germany). Electro-magnetic field simulations and phantom tests of the setup were performed. In vivo maps of B1+, metabolite signals, and saturation-band efficiency were acquired across the torsos of eight volunteers. Results The combined (volume-transmit, local receive array) setup increased signal-to-noise ratio 2.6-fold 10 cm below the array (depth of the interventricular septum) compared to using the birdcage coil in transceiver mode. The simulated coefficient of variation for B1+ of the whole-body coil across the heart was 46.7% (surface coil 129.0%); and the in vivo measured value was 38.4%. Metabolite images of 2,3-diphosphoglycerate clearly resolved the ventricular blood pools, and muscle tissue was visible in phosphocreatine (PCr) maps. Amplitude-modulated saturation bands achieved 71±4% suppression of phosphocreatine PCr in chest-wall muscles. Subjects reported they were comfortable. Conclusion This easy-to-assemble, volume-transmit, local receive array coil combination significantly improves the homogeneity and field-of-view for metabolic imaging of the human heart at 7T. PMID:29073228

Abnormalities of capillary microarchitecture in a rat model of coronary ischemic congestive heart failure

PubMed Central

Chen, Jiqiu; Yaniz-Galende, Elisa; Kagan, Heather J.; Liang, Lifan; Hekmaty, Saboor; Giannarelli, Chiara

2015-01-01

The aim of the present study is to explore the role of capillary disorder in coronary ischemic congestive heart failure (CHF). CHF was induced in rats by aortic banding plus ischemia-reperfusion followed by aortic debanding. Coronary arteries were perfused with plastic polymer containing fluorescent dye. Multiple fluorescent images of casted heart sections and scanning electric microscope of coronary vessels were obtained to characterize changes in the heart. Cardiac function was assessed by echocardiography and in vivo hemodynamics. Stenosis was found in all levels of the coronary arteries in CHF. Coronary vasculature volume and capillary density in remote myocardium were significantly increased in CHF compared with control. This occurred largely in microvessels with a diameter of ≤3 μm. Capillaries in CHF had a tortuous structure, while normal capillaries were linear. Capillaries in CHF had inconsistent diameters, with assortments of narrowed and bulged segments. Their surfaces appeared rough, potentially indicating endothelial dysfunction in CHF. Segments of main capillaries between bifurcations were significantly shorter in length in CHF than in control. Transiently increasing preload by injecting 50 μl of 30% NaCl demonstrated that the CHF heart had lower functional reserve; this may be associated with congestion in coronary microcirculation. Ischemic coronary vascular disorder is not limited to the main coronary arteries, as it occurs in arterioles and capillaries. Capillary disorder in CHF included stenosis, deformed structure, proliferation, and roughened surfaces. This disorder in the coronary artery architecture may contribute to the reduction in myocyte contractility in the setting of heart failure. PMID:25659485

A model of fluid and solute exchange in the human: validation and implications.

PubMed

Bert, J L; Gyenge, C C; Bowen, B D; Reed, R K; Lund, T

2000-11-01

In order to understand better the complex, dynamic behaviour of the redistribution and exchange of fluid and solutes administered to normal individuals or to those with acute hypovolemia, mathematical models are used in addition to direct experimental investigation. Initial validation of a model developed by our group involved data from animal experiments (Gyenge, C.C., Bowen, B.D., Reed, R.K. & Bert, J.L. 1999b. Am J Physiol 277 (Heart Circ Physiol 46), H1228-H1240). For a first validation involving humans, we compare the results of simulations with a wide range of different types of data from two experimental studies. These studies involved administration of normal saline or hypertonic saline with Dextran to both normal and 10% haemorrhaged subjects. We compared simulations with data including the dynamic changes in plasma and interstitial fluid volumes VPL and VIT respectively, plasma and interstitial colloid osmotic pressures PiPL and PiIT respectively, haematocrit (Hct), plasma solute concentrations and transcapillary flow rates. The model predictions were overall in very good agreement with the wide range of experimental results considered. Based on the conditions investigated, the model was also validated for humans. We used the model both to investigate mechanisms associated with the redistribution and transport of fluid and solutes administered following a mild haemorrhage and to speculate on the relationship between the timing and amount of fluid infusions and subsequent blood volume expansion.

The overloaded right heart and ventricular interdependence.

PubMed

Naeije, Robert; Badagliacca, Roberto

2017-10-01

The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

The algorithm study for using the back propagation neural network in CT image segmentation

NASA Astrophysics Data System (ADS)

Zhang, Peng; Liu, Jie; Chen, Chen; Li, Ying Qi

2017-01-01

Back propagation neural network(BP neural network) is a type of multi-layer feed forward network which spread positively, while the error spread backwardly. Since BP network has advantages in learning and storing the mapping between a large number of input and output layers without complex mathematical equations to describe the mapping relationship, it is most widely used. BP can iteratively compute the weight coefficients and thresholds of the network based on the training and back propagation of samples, which can minimize the error sum of squares of the network. Since the boundary of the computed tomography (CT) heart images is usually discontinuous, and it exist large changes in the volume and boundary of heart images, The conventional segmentation such as region growing and watershed algorithm can't achieve satisfactory results. Meanwhile, there are large differences between the diastolic and systolic images. The conventional methods can't accurately classify the two cases. In this paper, we introduced BP to handle the segmentation of heart images. We segmented a large amount of CT images artificially to obtain the samples, and the BP network was trained based on these samples. To acquire the appropriate BP network for the segmentation of heart images, we normalized the heart images, and extract the gray-level information of the heart. Then the boundary of the images was input into the network to compare the differences between the theoretical output and the actual output, and we reinput the errors into the BP network to modify the weight coefficients of layers. Through a large amount of training, the BP network tend to be stable, and the weight coefficients of layers can be determined, which means the relationship between the CT images and the boundary of heart.

Prenatal Mechanistic Target of Rapamycin Complex 1 (m TORC1) Inhibition by Rapamycin Treatment of Pregnant Mice Causes Intrauterine Growth Restriction and Alters Postnatal Cardiac Growth, Morphology, and Function.

PubMed

Hennig, Maria; Fiedler, Saskia; Jux, Christian; Thierfelder, Ludwig; Drenckhahn, Jörg-Detlef

2017-08-04

Fetal growth impacts cardiovascular health throughout postnatal life in humans. Various animal models of intrauterine growth restriction exhibit reduced heart size at birth, which negatively influences cardiac function in adulthood. The mechanistic target of rapamycin complex 1 (mTORC1) integrates nutrient and growth factor availability with cell growth, thereby regulating organ size. This study aimed at elucidating a possible involvement of mTORC1 in intrauterine growth restriction and prenatal heart growth. We inhibited mTORC1 in fetal mice by rapamycin treatment of pregnant dams in late gestation. Prenatal rapamycin treatment reduces mTORC1 activity in various organs at birth, which is fully restored by postnatal day 3. Rapamycin-treated neonates exhibit a 16% reduction in body weight compared with vehicle-treated controls. Heart weight decreases by 35%, resulting in a significantly reduced heart weight/body weight ratio, smaller left ventricular dimensions, and reduced cardiac output in rapamycin- versus vehicle-treated mice at birth. Although proliferation rates in neonatal rapamycin-treated hearts are unaffected, cardiomyocyte size is reduced, and apoptosis increased compared with vehicle-treated neonates. Rapamycin-treated mice exhibit postnatal catch-up growth, but body weight and left ventricular mass remain reduced in adulthood. Prenatal mTORC1 inhibition causes a reduction in cardiomyocyte number in adult hearts compared with controls, which is partially compensated for by an increased cardiomyocyte volume, resulting in normal cardiac function without maladaptive left ventricular remodeling. Prenatal rapamycin treatment of pregnant dams represents a new mouse model of intrauterine growth restriction and identifies an important role of mTORC1 in perinatal cardiac growth. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Fluid Redistribution and Heart Rate in Humans During Whole-Body Tilting, G(z) Centrifugation, and Lower Body Negative Pressure

NASA Technical Reports Server (NTRS)

Watenpaugh, D. E.; Breit, G. A.; Ballard, R. E.; Murthy, G.; Hargens, A. R.

1994-01-01

Gravity creates blood pressure gradients which redistribute body fluids towards the feet. Positive G(z) centrifugation and lower body negative pressure (LBNP) have been proposed to simulate these and other effects of gravity during long-term existence in microgravity. We hypothesized that the magnitude of upper-to-lower body fluid redistribution would increase according to the following order: short-arm centrifugation (SAC), long-arm centrifugation (LAC), head-up tilt (HUT), and LBNP. To test this hypothesis, we employed strain gauge plethysmography of the neck, thigh and calf during HUT and supine SAC and LAC up to lG(z) at the feet, and during supine LBNP to 100 mm Hg. Supine 100 mm Hg LBNP generates footward force and produces transmural blood pressures in the foot approximately equal to 1 G(z) (90 deg) HUT. Heart rate was measured via cardiotachometry. Control measurements were made while supine. SAC and LAC elicited similar increases in thigh volume at 1 G(z) (2.3 +/- 0.4 and 2.1 +/- 0.1%, respectively; mean +/- se, n greater than or equal to 7). At 100 mm Hg LBNP, thigh volume increased (3.4 +/- 0.3%) significantly more than during l G(z) centrifugation (p less than 0.05). Surprisingly, due to a paradoxical 0.6% reduction of thigh volume between 0.8 and 1.0 G(z) HUT, thigh volume was increased only 0.6 +/- 0.3% at 1 G(z) HUT. The calf demonstrated similar, although less definitive, responses to the various gravitational stimuli. Neck volume tended to decrease less during HUT than during the other stimuli. Heart rate increased similarly during HUT (18 +/- 2 beats/min) and LAC (12 +/- 2 beats/min), and exhibited still greater elevation during LBNP (29 +/- 4 beats/min), yet did not increase during SAC. These results suggest upright posture activates mechanisms that counteract footward fluid redistribution which are not activated during supine applications of simulated gravity. LAC more closely approximated effects of normal gravity (HUT) than LBNP. Therefore, when considering LBNP to simulate gravity, these findings support efforts to reduce the cardiovascular stress imposed by LBNP, while preserving the gravity-like force generated by LBNP.

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.

Postoperative Reverse Remodeling and Symptomatic Improvement in Normal-Flow Low-Gradient Aortic Stenosis After Aortic Valve Replacement.

PubMed

Carter-Storch, Rasmus; Møller, Jacob E; Christensen, Nicolaj L; Irmukhadenov, Akhmadjon; Rasmussen, Lars M; Pecini, Redi; Øvrehus, Kristian A; Søndergård, Eva V; Marcussen, Niels; Dahl, Jordi S

2017-12-01

Severe aortic stenosis (AS) most often presents with reduced aortic valve area (<1 cm 2 ), normal stroke volume index (≥35 mL/m 2 ), and either high mean gradient (≥40 mm Hg; normal-flow high-gradient AS) or low mean gradient (normal-flow low-gradient [NFLG] AS). The benefit of aortic valve replacement (AVR) among NFLG patients is controversial. We compared the impact of NFLG condition on preoperative left ventricular (LV) remodeling and myocardial fibrosis and postoperative remodeling and symptomatic benefit. Eighty-seven consecutive patients with reduced aortic valve area and normal stroke volume index undergoing AVR underwent echocardiography, magnetic resonance imaging, a 6-minute walk test, and measurement of natriuretic peptides before and 1 year after AVR. Myocardial fibrosis was assessed from magnetic resonance imaging. Patients were stratified as NFLG or normal-flow high-gradient. In total, 33 patients (38%) had NFLG. Before AVR, they were characterized by similar symptom burden but less severe AS measured by aortic valve area index (0.50±0.09 versus 0.40±0.08 cm 2 /m 2 ; P <0.0001), lower LV mass index (74±18 versus 90±26 g/m 2 ; P =0.01), but the same degree of myocardial fibrosis. After AVR, NFLG had a smaller reduction in LV mass index (-3±10 versus -±18 g/m 2 ; P <0.0001) and a smaller reduction in natriuretic peptides. Both groups experienced similar symptomatic improvement. Normal-flow high-gradient condition independently predicted change in LV mass index. Patients with NFLG had less severe AS and LV remodeling than patients with normal-flow high-gradient. Furthermore, NFLG patients experienced less reverse remodeling but the same symptomatic benefit. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02316587. © 2017 American Heart Association, Inc.

NOTE: Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

NASA Astrophysics Data System (ADS)

Umur, Asli; van Gemert, Martin J. C.; van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; Nikkels, Peter G. J.

2004-07-01

An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin.

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.

Volumetric modulation arc radiotherapy with flattening filter-free beams compared with static gantry IMRT and 3D conformal radiotherapy for advanced esophageal cancer: a feasibility study.

PubMed

Nicolini, Giorgia; Ghosh-Laskar, Sarbani; Shrivastava, Shyam Kishore; Banerjee, Sushovan; Chaudhary, Suresh; Agarwal, Jai Prakash; Munshi, Anusheel; Clivio, Alessandro; Fogliata, Antonella; Mancosu, Pietro; Vanetti, Eugenio; Cozzi, Luca

2012-10-01

A feasibility study was performed to evaluate RapidArc (RA), and the potential benefit of flattening filter-free beams, on advanced esophageal cancer against intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT). The plans for 3D-CRT and IMRT with three to seven and five to seven fixed beams were compared against double-modulated arcs with avoidance sectors to spare the lungs for 10 patients. All plans were optimized for 6-MV photon beams. The RA plans were studied for conventional and flattening filter-free (FFF) beams. The objectives for the planning target volume were the volume receiving ≥ 95% or at most 107% of the prescribed dose of <1% with a dose prescription of 59.4 Gy. For the organs at risk, the lung volume (minus the planning target volume) receiving ≥ 5 Gy was <60%, that receiving 20 Gy was <20%-30%, and the mean lung dose was <15.0 Gy. The heart volume receiving 45 Gy was <20%, volume receiving 30 Gy was <50%. The spinal dose received by 1% was <45 Gy. The technical delivery parameters for RA were assessed to compare the normal and FFF beam characteristics. RA and IMRT provided equivalent coverage and homogeneity, slightly superior to 3D-CRT. The conformity index was 1.2 ± 0.1 for RA and IMRT and 1.5 ± 0.2 for 3D-CRT. The mean lung dose was 12.2 ± 4.5 for IMRT, 11.3 ± 4.6 for RA, and 10.8 ± 4.4 for RA with FFF beams, 18.2 ± 8.5 for 3D-CRT. The percentage of volume receiving ≥ 20 Gy ranged from 23.6% ± 9.1% to 21.1% ± 9.7% for IMRT and RA (FFF beams) and 39.2% ± 17.0% for 3D-CRT. The heart and spine objectives were met by all techniques. The monitor units for IMRT and RA were 457 ± 139, 322 ± 20, and 387 ± 40, respectively. RA with FFF beams showed, compared with RA with normal beams, a ∼20% increase in monitor units per Gray, a 90% increase in the average dose rate, and 20% reduction in beam on time (owing to different gantry speeds). RA demonstrated, compared with conventional IMRT, a similar target coverage and some better dose sparing to the organs at risk; the advantage against conventional 3D-CRT was more evident. RA with FFF beams resulted in minor improvements in plan quality but with the potential for additional useful reduction in the treatment time. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

Atrial contribution to ventricular filling in mitral stenosis.

PubMed

Meisner, J S; Keren, G; Pajaro, O E; Mani, A; Strom, J A; Frater, R W; Laniado, S; Yellin, E L

1991-10-01

The importance of the contribution of atrial systole to ventricular filling in mitral stenosis is controversial. The cause of reduced cardiac output following the onset of atrial fibrillation may be due to an increased heart rate, a loss of booster pump function, or both. We studied the atrial contribution to filling under a variety of conditions by combining noninvasive studies of patients with computer modeling. Thirty patients in sinus rhythm with mild-to-severe stenosis were studied with two-dimensional and Doppler echocardiography for measurement of mitral flow velocity and mitral valve area (MVA). The mean +/- SD atrial contribution to left ventricular filling volume was 18 +/- 10% and varied inversely with mitral resistance. Patients with mild mitral stenosis (MVA, 1.8 +/- 0.7 cm2) and severe mitral stenosis (MVA, 0.9 +/- 0.2 cm2) had atrial contributions of 29 +/- 4% and 9 +/- 5%, respectively. The pathophysiological mechanisms responsible for these trends were further investigated by the computer model. In modeled severe mitral stenosis, increasing heart rate from 75 to 150 beats/min caused an increase of 5.2 mm Hg in mean left atrial pressure, whereas loss of atrial contraction at a heart rate of 150 beats/min caused only a 1.3 mm Hg increase. The atrial booster pump contributes less to ventricular filling in mitral stenosis than in the normal heart, and the loss of atrial pump function is less important than the effect of increasing heart rate as the cause of decompensation during atrial fibrillation.

Cardiac Dysfunction in HIV-1 Transgenic Mouse: Role of Stress and BAG3.

PubMed

Cheung, Joseph Y; Gordon, Jennifer; Wang, JuFang; Song, Jianliang; Zhang, Xue-Qian; Tilley, Douglas G; Gao, Erhe; Koch, Walter J; Rabinowitz, Joseph; Klotman, Paul E; Khalili, Kamel; Feldman, Arthur M

2015-08-01

Since highly active antiretroviral therapy improved long-term survival of acquired immunodeficiency syndrome (AIDS) patients, AIDS cardiomyopathy has become an increasingly relevant clinical problem. We used human immunodeficiency virus (HIV)-1 transgenic (Tg26) mouse to explore molecular mechanisms of AIDS cardiomyopathy. Tg26 mice had significantly lower left ventricular (LV) mass and smaller end-diastolic and end-systolic LV volumes. Under basal conditions, cardiac contractility and relaxation and single myocyte contraction dynamics were not different between wild-type (WT) and Tg26 mice. Ten days after open heart surgery, contractility and relaxation remained significantly depressed in Tg26 hearts, suggesting that Tg26 mice did not tolerate surgical stress well. To simulate heart failure in which expression of Bcl2-associated athanogene 3 (BAG3) is reduced, we down-regulated BAG3 by small hairpin ribonucleic acid in WT and Tg26 hearts. BAG3 down-regulation significantly reduced contractility in Tg26 hearts. BAG3 overexpression rescued contractile abnormalities in myocytes expressing the HIV-1 protein Tat. We conclude: (i) Tg26 mice exhibit normal contractile function at baseline; (ii) Tg26 mice do not tolerate surgical stress well; (iii) BAG3 down-regulation exacerbated cardiac dysfunction in Tg26 mice; (iv) BAG3 overexpression rescued contractile abnormalities in myocytes expressing HIV-1 protein Tat; and (v) BAG3 may occupy a role in pathogenesis of AIDS cardiomyopathy. © 2015 Wiley Periodicals, Inc.

Ambulatory Monitoring of Congestive Heart Failure by Multiple Bioelectric Impedance Vectors

PubMed Central

Khoury, Dirar S.; Naware, Mihir; Siou, Jeff; Blomqvist, Andreas; Mathuria, Nilesh S.; Wang, Jianwen; Shih, Hue-Teh; Nagueh, Sherif F.; Panescu, Dorin

2009-01-01

Objectives To investigate properties of multiple bioelectric impedance signals recorded during congestive heart failure (CHF) by utilizing various electrode configurations of an implanted cardiac resynchronization therapy (CRT) system. Background Monitoring of CHF has relied mainly on right-heart sensors. Methods Fifteen normal dogs underwent implantation of CRT systems using standard leads. An additional left atrial (LA) pressure lead-sensor was implanted in 5 dogs. Continuous rapid right ventricular (RV) pacing was applied over several weeks. Left ventricular (LV) catheterization and echocardiography were performed biweekly. Six steady-state impedance signals, utilizing intrathorcaic and intracardiac vectors, were measured via ring (r), coil (c), and device Can electrodes. Results All animals developed CHF after 2–4 weeks of pacing. Impedance diminished gradually during CHF induction, but at varying rates for different vectors. Impedance during CHF decreased significantly in all measured vectors: LVr-Can, −17%; LVr-RVr, −15%; LVr-RAr, −11%; RVr-Can, −12%; RVc-Can, −7%; RAr-Can, −5%. The LVr-Can vector reflected both the fastest and largest change in impedance in comparison to vectors employing only right-heart electrodes, and was highly reflective of changes in LV end-diastolic volume and LA pressure. Conclusions Impedance, acquired via different lead-electrodes, have variable responses to CHF. Impedance vectors employing a LV lead are highly responsive to physiologic changes during CHF. Measuring multiple impedance signals could be useful for optimizing ambulatory monitoring in heart failure patients. PMID:19298923

Stroke volume variation as a guide for fluid resuscitation in patients undergoing large-volume liposuction.

PubMed

Jain, Anil Kumar; Khan, Asma M

2012-09-01

: The potential for fluid overload in large-volume liposuction is a source of serious concern. Fluid management in these patients is controversial and governed by various formulas that have been advanced by many authors. Basically, it is the ratio of what goes into the patient and what comes out. Central venous pressure has been used to monitor fluid therapy. Dynamic parameters, such as stroke volume and pulse pressure variation, are better predictors of volume responsiveness and are superior to static indicators, such as central venous pressure and pulmonary capillary wedge pressure. Stroke volume variation was used in this study to guide fluid resuscitation and compared with one guided by an intraoperative fluid ratio of 1.2 (i.e., Rohrich formula). : Stroke volume variation was used as a guide for intraoperative fluid administration in 15 patients subjected to large-volume liposuction. In another 15 patients, fluid resuscitation was guided by an intraoperative fluid ratio of 1.2. The amounts of intravenous fluid administered in the groups were compared. : The mean amount of fluid infused was 561 ± 181 ml in the stroke volume variation group and 2383 ± 1208 ml in the intraoperative fluid ratio group. The intraoperative fluid ratio when calculated for the stroke volume variation group was 0.936 ± 0.084. All patients maintained hemodynamic parameters (heart rate and systolic, diastolic, and mean blood pressure). Renal and metabolic indices remained within normal limits. : Stroke volume variation-guided fluid application could result in an appropriate amount of intravenous fluid use in patients undergoing large-volume liposuction. : Therapeutic, II.

[Computer-aided Diagnosis and New Electronic Stethoscope].

PubMed

Huang, Mei; Liu, Hongying; Pi, Xitian; Ao, Yilu; Wang, Zi

2017-05-30

Auscultation is an important method in early-diagnosis of cardiovascular disease and respiratory system disease. This paper presents a computer-aided diagnosis of new electronic auscultation system. It has developed an electronic stethoscope based on condenser microphone and the relevant intelligent analysis software. It has implemented many functions that combined with Bluetooth, OLED, SD card storage technologies, such as real-time heart and lung sounds auscultation in three modes, recording and playback, auscultation volume control, wireless transmission. The intelligent analysis software based on PC computer utilizes C# programming language and adopts SQL Server as the background database. It has realized play and waveform display of the auscultation sound. By calculating the heart rate, extracting the characteristic parameters of T1, T2, T12, T11, it can analyze whether the heart sound is normal, and then generate diagnosis report. Finally the auscultation sound and diagnosis report can be sent to mailbox of other doctors, which can carry out remote diagnosis. The whole system has features of fully function, high portability, good user experience, and it is beneficial to promote the use of electronic stethoscope in the hospital, at the same time, the system can also be applied to auscultate teaching and other occasions.

Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation.

PubMed

Mekkaoui, Choukri; Huang, Shuning; Chen, Howard H; Dai, Guangping; Reese, Timothy G; Kostis, William J; Thiagalingam, Aravinda; Maurovich-Horvat, Pal; Ruskin, Jeremy N; Hoffmann, Udo; Jackowski, Marcel P; Sosnovik, David E

2012-10-12

The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p < 0.05). This was confirmed histologically by the reduction of HA in the subepicardium from -52.03° ± 2.94° in normal hearts to -37.48° ± 4.05° in the remote zone of the remodeled hearts (p < 0.05). A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward) shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.

Physiological Characterization of the SynCardia Total Artificial Heart in a Mock Circulation System

PubMed Central

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

2014-01-01

The SynCardia total artificial heart (TAH) has emerged as an effective, life-saving bi-ventricular replacement system for a wide variety of patients with end-stage heart failure. While the clinical performance of the TAH is established, modern physiologic characterization, in terms of elastance behavior and pressure-volume characterization has not been defined. Herein we examine the TAH in terms of elastance using a non-ejecting left-ventricle, and then characterize the pressure-volume relationship 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. Further, we show that the TAH has a pressure-volume relationship 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 to the human heart. PMID:25551416

[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.

Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

NASA Technical Reports Server (NTRS)

Nandi, P. S.; Spodick, D. H.

1977-01-01

The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

Ultrasound functional imaging in an ex vivo beating porcine heart platform

NASA Astrophysics Data System (ADS)

Petterson, Niels J.; Fixsen, Louis S.; Rutten, Marcel C. M.; Pijls, Nico H. J.; van de Vosse, Frans N.; Lopata, Richard G. P.

2017-12-01

In recent years, novel ultrasound functional imaging (UFI) techniques have been introduced to assess cardiac function by measuring, e.g. cardiac output (CO) and/or myocardial strain. Verification and reproducibility assessment in a realistic setting remain major issues. Simulations and phantoms are often unrealistic, whereas in vivo measurements often lack crucial hemodynamic parameters or ground truth data, or suffer from the large physiological and clinical variation between patients when attempting clinical validation. Controlled validation in certain pathologies is cumbersome and often requires the use of lab animals. In this study, an isolated beating pig heart setup was adapted and used for performance assessment of UFI techniques such as volume assessment and ultrasound strain imaging. The potential of performing verification and reproducibility studies was demonstrated. For proof-of-principle, validation of UFI in pathological hearts was examined. Ex vivo porcine hearts (n  =  6, slaughterhouse waste) were resuscitated and attached to a mock circulatory system. Radio frequency ultrasound data of the left ventricle were acquired in five short axis views and one long axis view. Based on these slices, the CO was measured, where verification was performed using flow sensor measurements in the aorta. Strain imaging was performed providing radial, circumferential and longitudinal strain to assess reproducibility and inter-subject variability under steady conditions. Finally, strains in healthy hearts were compared to a heart with an implanted left ventricular assist device, simulating a failing, supported heart. Good agreement between ultrasound and flow sensor based CO measurements was found. Strains were highly reproducible (intraclass correlation coefficients  >0.8). Differences were found due to biological variation and condition of the hearts. Strain magnitude and patterns in the assisted heart were available for different pump action, revealing large changes compared to the normal condition. The setup provides a valuable benchmarking platform for UFI techniques. Future studies will include work on different pathologies and other means of measurement verification.

Normal overall leakiness of microvasculature for albumin in patients with chronic obstructive lung disease (COLD).

PubMed

Henriksen, J H; Kok-Jensen, A

1984-04-01

The overall extravasation rate of albumin, TER (i.e. the fraction of the intravascular albumin mass (IVM) passing into, and during steady state returning from, the extravascular space per unit time) was determined from the disappearance of i.v. injected radioiodinated serum albumin in seven patients with severe chronic obstructive lung disease (COLD) and in seven normal controls. Arterial oxygen tension in patients with COLD was median 60 mmHg (range 47-80, normal greater than 75 mmHg), vital capacity was on the average 55% of expected normal value (median 1.80 litre, range 1.45-1.95), and forced expired volume in first sec was decreased to 21% of expected normal value (median 0.55 litre, range 0.40-0.70). Right-heart catheterization revealed pulmonary hypertension in all but one patient. TER in patients with COLD was median 6.1% IVM/h (range 3.5-10.1) as compared to that of normal controls 6.0% IVM/h (range 4.3-7.4), indicating that no significant change in microvascular leakiness to albumin could be found in patients with COLD. Thus, the results bring no support to a generally increased microvascular permeability to proteins in patients with COLD.

Disruption of Desmin-Mitochondrial Architecture in Patients with Regurgitant Mitral Valves and Preserved Ventricular Function

PubMed Central

Soorappan, Rajasekaran Namakkal; Ahmad, Shama; Mariappan, Nithya; Litovsky, Silvio; Gupta, Himanshu; Lloyd, Steven G; Denney, Thomas S; Powell, Pamela Cox; Aban, Inmaculada; Collawn, James; Davies, James E; McGiffin, David C; Dell’Italia, Louis J

2016-01-01

Objective Recent studies have demonstrated improved outcomes in patients receiving early surgery for degenerative mitral valvular regurgitation (MR) rather than adhering to conventional guidelines for surgical intervention. However, studies providing a mechanistic basis for these findings are limited. Methods Left ventricular (LV) myocardium from 22 patients undergoing mitral valve repair for Class I indications was evaluated for desmin, the voltage-dependent anion channel, αβ-crystallin, and α, β unsaturated aldehyde 4-hydroxynonelal by fluorescence microscopy and in 6 normal control LV autopsy specimens. Cardiomyocyte ultrastructure was examined by transmission electron microscopy. Magnetic resonance imaging with tissue tagging was performed in 55 normal subjects and 22 MR patients pre- and 6 months post-mitral valve repair. Results LV end-diastolic volume was 1.5-fold (p<0.0001) higher and LV mass to volume ratio was lower in MR (p=0.004) vs. normal and improvement six months after mitral valve surgery. However, LV ejection fraction decreased from 65 ± 7 to 52 ± 9% (p<0.0001) and LV circumferential (p<0.0001) and longitudinal strain decreased significantly below normal values (p=0.002) post-surgery. MR hearts had a 53% decrease in desmin (p<0.0001) and a 2.6-fold increase in desmin aggregates (p<0.0001) vs. normal along with significant, intense perinuclear staining of α, β unsaturated aldehyde 4-hydroxynonelal in areas of mitochondrial breakdown and clustering. Transmission electron microscopy demonstrated numerous electron dense deposits, myofibrillar loss, Z-line abnormalities and extensive granulofilamentous debris identified as desmin positive by immunogold transmission electron microscopy. Conclusion Despite well-preserved preoperative LV ejection fraction, severe oxidative stress and disruption of cardiomyocyte desmin-mitochondrial sarcomeric architecture may explain post-operative LV functional decline and further supports the move toward earlier surgical intervention. PMID:27464577

Comprehensive characterisation of hypertensive heart disease left ventricular phenotypes

PubMed Central

Rodrigues, Jonathan C L; Amadu, Antonio Matteo; Dastidar, Amardeep Ghosh; Szantho, Gergley V; Lyen, Stephen M; Godsave, Cattleya; Ratcliffe, Laura E K; Burchell, Amy E; Hart, Emma C; Hamilton, Mark C K; Nightingale, Angus K; Paton, Julian F R; Manghat, Nathan E; Bucciarelli-Ducci, Chiara

2016-01-01

Objective Myocardial intracellular/extracellular structure and aortic function were assessed among hypertensive left ventricular (LV) phenotypes using cardiovascular magnetic resonance (CMR). Methods An observational study from consecutive tertiary hypertension clinic patients referred for CMR (1.5 T) was performed. Four LV phenotypes were defined: (1) normal with normal indexed LV mass (LVM) and LVM to volume ratio (M/V), (2) concentric remodelling with normal LVM but elevated M/V, (3) concentric LV hypertrophy (LVH) with elevated LVM but normal indexed end-diastolic volume (EDV) or (4) eccentric LVH with elevated LVM and EDV. Extracellular volume fraction was measured using T1-mapping. Circumferential strain was calculated by voxel-tracking. Aortic distensibility was derived from high-resolution aortic cines and contemporaneous blood pressure measurements. Results 88 hypertensive patients (49±14 years, 57% men, systolic blood pressure (SBP): 167±30 mm Hg, diastolic blood pressure (DBP): 96±14 mm Hg) were compared with 29 age-matched/sex-matched controls (47±14 years, 59% men, SBP: 128±12 mm Hg, DBP: 79±10 mm Hg). LVH resulted from increased myocardial cell volume (eccentric LVH: 78±19 mL/m2 vs concentric LVH: 73±15 mL/m2 vs concentric remodelling: 55±9 mL/m2, p<0.05, respectively) and interstitial fibrosis (eccentric LVH: 33±10 mL/m2 vs concentric LVH: 30±10 mL/m2 vs concentricremodelling: 19±2 mL/m2, p<0.05, respectively). LVH had worst circumferential impairment (eccentric LVH: −12.8±4.6% vs concentric LVH: −15.5±3.1% vs concentric remodelling: –17.1±3.2%, p<0.05, respectively). Concentric remodelling was associated with reduced aortic distensibility, but not with large intracellular/interstitial expansion or myocardial dysfunction versus controls. Conclusions Myocardial interstitial fibrosis varies across hypertensive LV phenotypes with functional consequences. Eccentric LVH has the most fibrosis and systolic impairment. Concentric remodelling is only associated with abnormal aortic function. Understanding these differences may help tailor future antihypertensive treatments. PMID:27260191

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.

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 age and gender on sudomotor and cardiovagal function and blood pressure response to tilt in normal subjects

NASA Technical Reports Server (NTRS)

Low, P. A.; Denq, J. C.; Opfer-Gehrking, T. L.; Dyck, P. J.; O'Brien, P. C.; Slezak, J. M.

1997-01-01

Normative data are limited on autonomic function tests, especially beyond age 60 years. We therefore evaluated these tests in a total of 557 normal subjects evenly distributed by age and gender from 10 to 83 years. Heart rate (HR) response to deep breathing fell with increasing age. Valsalva ratio varied with both age and gender. QSART (quantitative sudomotor axon-reflex test) volume was consistently greater in men (approximately double) and progressively declined with age for all three lower extremity sites but not the forearm site. Orthostatic blood pressure reduction was greater with increasing age. HR at rest was significantly higher in women, and the increment with head-up tilt fell with increasing age. For no tests did we find a regression to zero, and some tests seem to level off with increasing age, indicating that diagnosis of autonomic failure was possible to over 80 years of age.

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.

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

Strain, strain rate, and the force frequency relationship in patients with and without heart failure.

PubMed

Mak, Susanna; Van Spall, Harriette G C; Wainstein, Rodrigo V; Sasson, Zion

2012-03-01

The aim of this study was to examine the effect of heart rate (HR) on indices of deformation in adults with and without heart failure (HF) who underwent simultaneous high-fidelity catheterization of the left ventricle to describe the force-frequency relationship. Right atrial pacing to control HR and high-fidelity recordings of left ventricular (LV) pressure were used to inscribe the force-frequency relationship. Simultaneous two-dimensional echocardiographic imaging was acquired for speckle-tracking analysis. Thirteen patients with normal LV function and 12 with systolic HF (LV ejection fraction, 31 ± 13%) were studied. Patients with HF had depressed isovolumic contractility and impaired longitudinal strain and strain rate. HR-dependent increases in LV+dP/dt(max), the force-frequency relationship, was demonstrated in both groups (normal LV function, baseline to 100 beats/min: 1,335 ± 296 to 1,564 ± 320 mm Hg/sec, P < .0001; HF, baseline to 100 beats/min: 970 ± 207 to 1,083 ± 233 mm Hg/sec, P < .01). Longitudinal strain decreased significantly (normal LV function, baseline to 100 beats/min: 18.0 ± 3.5% to 10.8 ± 6.0%, P < .001; HF: 9.4 ± 4.1% to 7.5 ± 3.4%, P < .01). The decrease in longitudinal strain was related to a decrease in LV end-diastolic dimensions. Strain rate did not change with right atrial pacing. Despite the inotropic effect of increasing HR, longitudinal strain decreases in parallel with stroke volume as load-dependent indices of ejection. Strain rate did not reflect the modest HR-related changes in contractility; on the other hand, the use of strain rate for quantitative stress imaging is also less likely to be confounded by chronotropic responses. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Effects of imposed acid-base derangement on the cardiovascular effects and pharmacokinetics of bupivacaine and thiopental.

PubMed

Mather, Laurence E; Ladd, Leigh A; Copeland, Susan E; Chang, Dennis H-T

2004-06-01

By changing physicochemical properties such as effective lipophilicity, changes in blood pH could alter the distribution, elimination, and effects of weakly ionizing drugs. The authors examined the outcome of imposed acid-base derangement on cardiovascular effects and myocardial and whole body pharmacokinetics of bupivacaine, a weak base, and thiopental, a weak acid. Intravenous infusions of rac-bupivacaine HCl (37.5 mg) or rac-thiopental sodium (250 mg, subanesthetic dose) were administered over 3 min to previously instrumented conscious ewes with normal blood pH, acidemia imposed by lactic acid infusion, or alkalemia imposed by bicarbonate infusion. Hemodynamic and electrocardiographic effects were recorded; arterial and coronary sinus drug blood concentrations were analyzed by chiral high-performance liquid chromatography. Bupivacaine decreased myocardial contractility, coronary perfusion, heart rate, and cardiac output; however, cardiac output and stroke volume were not as affected by bupivacaine with acidemia. Thiopental decreased myocardial contractility and stroke volume and increased heart rate; acidemia enhanced the tachycardia and produced a greater decrease in stroke volume than with alkalemia. Taken as a whole, the cardiovascular changes were not systematically modified by acid-base derangement. Overall, the tissue distribution of bupivacaine was favored by alkalemia, but thiopental pharmacokinetics were essentially unaffected by acid-base derangement. Acid-base derangement did not influence the kinetics of either drug enantioselectively. At the doses used, the hemodynamic and electrocardiographic effects of bupivacaine and thiopental were not systematically modified by acid-base derangement, nor were there changes in regional or whole body pharmacokinetics of either drug that were clearly related to acid-base status.

Supine exercise during lower body negative pressure effectively simulates upright exercise in normal gravity

NASA Technical Reports Server (NTRS)

Murthy, G.; Watenpaugh, D. E.; Ballard, R. E.; Hargens, A. R.

1994-01-01

Exercise within a lower body negative pressure (LBNP) chamber in supine posture was compared with similar exercise against Earth's gravity (without LBNP) in upright posture in nine healthy male volunteers. We measured footward force with a force plate, pressure in soleus and tibialis anterior muscles of the leg with transducer-tipped catheters, calf volume by strain gauge plethysmography, heart rate, and systolic and diastolic blood pressures during two conditions: 1) exercise in supine posture within an LBNP chamber during 100-mmHg LBNP (exercise-LBNP) and 2) exercise in upright posture against Earth's gravity without LBNP (exercise-1 G). Subjects exercised their ankle joints (dorsi- and plantarflexions) for 5 min during exercise-LBNP and for 5 min during exercise-1 G. Mean footward force produced during exercise-LBNP (743 +/- 37 N) was similar to that produced during exercise-1 G (701 +/- 24 N). Peak contraction pressure in the antigravity soleus muscle during exercise-LBNP (115 +/- 10 mmHg) was also similar to that during exercise-1 G (103 +/- 13 mmHg). Calf volume increased significantly by 3.3 +/- 0.5% during exercise-LBNP compared with baseline values. Calf volume did not increase significantly during exercise-1 G. Heart rate was significantly higher during exercise-LBNP (99 +/- 5 beats/min) than during exercise-1 G (81 +/- 3 beats/min). These results indicate that exercise in supine posture within an LBNP chamber can produce similar musculoskeletal stress in the legs and greater systemic cardiovascular stress than exercise in the upright posture against Earth's gravity.

Cardiac-restricted Overexpression of TRAF3 Interacting Protein 2 (TRAF3IP2) Results in Spontaneous Development of Myocardial Hypertrophy, Fibrosis, and Dysfunction *

PubMed Central

Sakamuri, Siva S. V. P.; Siddesha, Jalahalli M.; Saifudeen, Zubaida; Ma, Lixin; Siebenlist, Ulrich; Gardner, Jason D.; Chandrasekar, Bysani

2016-01-01

TRAF3IP2 (TRAF3 interacting protein 2; previously known as CIKS or Act1) is a key intermediate in the normal inflammatory response and the pathogenesis of various autoimmune and inflammatory diseases. Induction of TRAF3IP2 activates IκB kinase (IKK)/NF-κB, JNK/AP-1, and c/EBPβ and stimulates the expression of various inflammatory mediators with negative myocardial inotropic effects. To investigate the role of TRAF3IP2 in heart disease, we generated a transgenic mouse model with cardiomyocyte-specific TRAF3IP2 overexpression (TRAF3IP2-Tg). Echocardiography, magnetic resonance imaging, and pressure-volume conductance catheterization revealed impaired cardiac function in 2-month-old male transgenic (Tg) mice as evidenced by decreased ejection fraction, stroke volume, cardiac output, and peak ejection rate. Moreover, the male Tg mice spontaneously developed myocardial hypertrophy (increased heart/body weight ratio, cardiomyocyte cross-sectional area, GATA4 induction, and fetal gene re-expression). Furthermore, TRAF3IP2 overexpression resulted in the activation of IKK/NF-κB, JNK/AP-1, c/EBPβ, and p38 MAPK and induction of proinflammatory cytokines, chemokines, and extracellular matrix proteins in the heart. Although myocardial hypertrophy decreased with age, cardiac fibrosis (increased number of myofibroblasts and enhanced expression and deposition of fibrillar collagens) increased progressively. Despite these adverse changes, TRAF3IP2 overexpression did not result in cell death at any time period. Interestingly, despite increased mRNA expression, TRAF3IP2 protein levels and activation of its downstream signaling intermediates remained unchanged in the hearts of female Tg mice. The female Tg mice also failed to develop myocardial hypertrophy. In summary, these results demonstrate that overexpression of TRAF3IP2 in male mice is sufficient to induce myocardial hypertrophy, cardiac fibrosis, and contractile dysfunction. PMID:27466370

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

Prolonged Tp-e Interval in Down Syndrome Patients with Congenitally Normal Hearts.

PubMed

Kucuk, Mehmet; Karadeniz, Cem; Ozdemir, Rahmi; Meşe, Timur

2018-03-25

Heterogeneity of ventricular repolarization has been assessed by using the QT dispersion in Down syndrome (DS) patients with congenitally normal hearts. However, novel repolarization indexes, the Tp-e interval and Tp-e/QT ratio, have not previously been evaluated in these patients. The aim of this study was to evaluate the Tp-e interval and Tp-e/QT ratio in DS patients without congenital heart defects. Twelve-lead surface electrocardiograms of 160 DS patients and 110 age- and sex-matched healthy controls were used to evaluate and compare the Tp-e interval, Tp-e dispersion, and Tp-e/QT ratio. Heart rate, Tp-e interval, Tp-e dispersion, Tp-e/QT and Tp-e/QTc ratios were significantly higher in DS group than in the controls. Myocardial repolarization indexes in DS patients with congenitally normal hearts were found to be prolonged compared to those in normal controls. Further evaluation is warranted to reveal a relationship between prolonged repolarization indexes and arrhythmic events in these patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pregnancy as a cardiac stress model

PubMed Central

Chung, Eunhee; Leinwand, Leslie A.

2014-01-01

Cardiac hypertrophy occurs during pregnancy as a consequence of both volume overload and hormonal changes. Both pregnancy- and exercise-induced cardiac hypertrophy are generally thought to be similar and physiological. Despite the fact that there are shared transcriptional responses in both forms of cardiac adaptation, pregnancy results in a distinct signature of gene expression in the heart. In some cases, however, pregnancy can induce adverse cardiac events in previously healthy women without any known cardiovascular disease. Peripartum cardiomyopathy is the leading cause of non-obstetric mortality during pregnancy. To understand how pregnancy can cause heart disease, it is first important to understand cardiac adaptation during normal pregnancy. This review provides an overview of the cardiac consequences of pregnancy, including haemodynamic, functional, structural, and morphological adaptations, as well as molecular phenotypes. In addition, this review describes the signalling pathways responsible for pregnancy-induced cardiac hypertrophy and angiogenesis. We also compare and contrast cardiac adaptation in response to disease, exercise, and pregnancy. The comparisons of these settings of cardiac hypertrophy provide insight into pregnancy-associated cardiac adaptation. PMID:24448313

Left Ventricular Diastolic and Systolic Material Property Estimation from Image Data

PubMed Central

Krishnamurthy, Adarsh; Villongco, Christopher; Beck, Amanda; Omens, Jeffrey; McCulloch, Andrew

2015-01-01

Cardiovascular simulations using patient-specific geometries can help researchers understand the mechanical behavior of the heart under different loading or disease conditions. However, to replicate the regional mechanics of the heart accurately, both the nonlinear passive and active material properties must be estimated reliably. In this paper, automated methods were used to determine passive material properties while simultaneously computing the unloaded reference geometry of the ventricles for stress analysis. Two different approaches were used to model systole. In the first, a physiologically-based active contraction model [1] coupled to a hemodynamic three-element Windkessel model of the circulation was used to simulate ventricular ejection. In the second, developed active tension was directly adjusted to match ventricular volumes at end-systole while prescribing the known end-systolic pressure. These methods were tested in four normal dogs using the data provided for the LV mechanics challenge [2]. The resulting end-diastolic and end-systolic geometry from the simulation were compared with measured image data. PMID:25729778

Heart rate variability and turbulence in hyperthyroidism before, during, and after treatment.

PubMed

Osman, Faizel; Franklyn, Jayne A; Daykin, Jacqueline; Chowdhary, Saqib; Holder, Roger L; Sheppard, Michael C; Gammage, Michael D

2004-08-15

Patients with subclinical and treated overt hyperthyroidism have an excess vascular mortality rate. Several symptoms and signs in overt hyperthyroidism suggest abnormality of cardiac autonomic function that may account in part for this excess mortality rate, but few studies have examined cardiac autonomic function in untreated and treated hyperthyroidism. We assessed heart rate turbulence (HRT) and time-domain parameters of heart rate variability in a large, unselected cohort of patients with overt hyperthyroidism referred to our thyroid clinic (n = 259) and compared findings with a group of normal subjects with euthyroidism (n = 440). These measures were also evaluated during antithyroid therapy (when serum-free thyroxine and triiodothyronine concentrations returned to normal but thyrotropin remained suppressed (i.e., subclinical hyperthyroidism, n = 110) and when subjects were rendered clinically and biochemically euthyroid (normal serum thyrotropin, free thyroxine and triiodothyronine concentrations, n = 219). We found that overall measures of heart rate variability and those specific for cardiac vagal modulation were attenuated in patients with overt hyperthyroidism compared with normal subjects; measurements of overall heart rate variability remained low in those with low levels of serum thyrotropin but returned to normal in patients with biochemical euthyroidism. Measurements of HRT (onset and slope) were also decreased in patients with overt hyperthyroidism, but HRT slope returned to normal values with antithyroid treatment. This study is the first to evaluate HRT in overt and treated hyperthyroidism.

Non-invasive pulmonary function test on Morquio Patients

PubMed Central

Kubaski, Francyne; Tomatsu, Shunji; Patel, Pravin; Shimada, Tsutomu; Xie, Li; Yasuda, Eriko; Mason, Robert; Mackenzie, William G.; Theroux, Mary; Bober, Michael B.; Oldham, Helen M.; Orii, Tadao; Shaffer, Thomas H.

2015-01-01

In clinical practice, respiratory function tests are difficult to perform in Morquio syndrome patients due to their characteristic skeletal dysplasia, small body size and lack of cooperation of young patients, where in some cases, conventional spirometry for pulmonary function is too challenging. To establish feasible clinical pulmonary endpoints and determine whether age impacts lung function in Morquio patients non-invasive pulmonary tests and conventional spirometry were evaluated. The non-invasive pulmonary tests: impulse oscillometry system, pneumotachography, and respiratory inductance plethysmography in conjunction with conventional spirometry were evaluated in twenty-two Morquio patients (18 Morquio A and 4 Morquio B) (7 males), ranging from 3 and 40 years of age. Twenty-two patients were compliant with non-invasive tests (100%) with exception of IOS (81.8%–18 patients). Seventeen patients (77.3%) were compliant with spirometry testing. All subjects had normal vital signs at rest including > 95% oxygen saturation, end tidal CO2 (38–44 mmHg), and age-appropriate heart rate (mean=98.3, standard deviation=19) (two patients were deviated). All patients preserved normal values in impulse oscillometry system, pneumotachography, and respiratory inductance plethysmography, although predicted forced expiratory volume total (72.8 ± 6.9 SE%) decreased with age and was below normal; phase angle (35.5 ± 16.5 Degrees), %Rib Cage (41.6 ± 12.7%), resonant frequency, and forced expiratory volume in one second/forced expiratory volume total (110.0 ± 3.2 SE%) were normal and not significantly impacted by age. The proposed non-invasive pulmonary function tests are able to cover a greater number of patients (young patients and/or wheel-chair bound), thus providing a new diagnostic approach for the assessment of lung function in Morquio syndrome which in many cases may be difficult to evaluate. Morquio patients studied herein demonstrated no clinical or functional signs of restrictive and/or obstructive lung disease. PMID:26116954

Left atrial enlargement increases the risk of major adverse cardiac events independent of coronary vasodilator capacity.

PubMed

Koh, Angela S; Murthy, Venkatesh L; Sitek, Arkadiusz; Gayed, Peter; Bruyere, John; Wu, Justina; Di Carli, Marcelo F; Dorbala, Sharmila

2015-09-01

Longstanding uncontrolled atherogenic risk factors may contribute to left atrial (LA) hypertension, LA enlargement (LAE) and coronary vascular dysfunction. Together they may better identify risk of major adverse cardiac events (MACE). The aim of this study was to test the hypothesis that chronic LA hypertension as assessed by LAE modifies the relationship between coronary vascular function and MACE. In 508 unselected subjects with a normal clinical (82)Rb PET/CT, ejection fraction ≥40 %, no prior coronary artery disease, valve disease or atrial fibrillation, LAE was determined based on LA volumes estimated from the hybrid perfusion and CT transmission scan images and indexed to body surface area. Absolute myocardial blood flow and global coronary flow reserve (CFR) were calculated. Subjects were systematically followed-up for the primary end-point - MACE - a composite of all-cause death, myocardial infarction, hospitalization for heart failure, stroke, coronary artery disease progression or revascularization. During a median follow-up of 862 days, 65 of the subjects experienced a composite event. Compared with subjects with normal LA size, subjects with LAE showed significantly lower CFR (2.25 ± 0.83 vs. 1.95 ± 0.80, p = 0.01). LAE independently and incrementally predicted MACE even after accounting for clinical risk factors, medication use, stress left ventricular ejection fraction, stress left ventricular end-diastolic volume index and CFR (chi-squared statistic increased from 30.9 to 48.3; p = 0.001). Among subjects with normal CFR, those with LAE had significantly worse event-free survival (risk adjusted HR 5.4, 95 % CI 2.3 - 12.8, p < 0.0001). LAE and reduced CFR are related but distinct cardiovascular adaptations to atherogenic risk factors. LAE is a risk marker for MACE independent of clinical factors and left ventricular volumes; individuals with LAE may be at risk of MACE despite normal coronary vascular function.

Paroxysmal supraventricular tachycardia (PSVT)

MedlinePlus

PSVT; Supraventricular tachycardia; Abnormal heart rhythm - PSVT; Arrhythmia - PSVT; Rapid heart rate - PSVT; Fast heart rate - PSVT ... Normally, the chambers of the heart (atria and ventricles) contract in ... are caused by an electrical signal that begins in an area ...

G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish

PubMed Central

Romano, Shannon N.; Edwards, Hailey E.; Ryan, Kevin J.

2017-01-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels. PMID:29065151

G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish.

PubMed

Romano, Shannon N; Edwards, Hailey E; Souder, Jaclyn Paige; Ryan, Kevin J; Cui, Xiangqin; Gorelick, Daniel A

2017-10-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels.

Mean circulatory filling pressure: its meaning and measurement.

PubMed

Rothe, C F

1993-02-01

The volume-pressure relationship of the vasculature of the body as a whole, its vascular capacitance, requires a measurement of the mean circulatory filling pressure (Pmcf). A change in vascular capacitance induced by reflexes, hormones, or drugs has physiological consequences similar to a rapid change in blood volume and thus strongly influences cardiac output. The Pmcf is defined as the mean vascular pressure that exists after a stop in cardiac output and redistribution of blood, so that all pressures are the same throughout the system. The Pmcf is thus related to the fullness of the circulatory system. A change in Pmcf provides a uniquely useful index of a change in overall venous smooth muscle tone if the blood volume is not concomitantly changed. The Pmcf also provides an estimate of the distending pressure in the small veins and venules, which contain most of the blood in the body and comprise most of the vascular compliance. Thus the Pmcf, which is normally independent of the magnitude of the cardiac output, provides an estimate of the upstream pressure that determines the rate of flow returning to the heart.

Circulatory failure during severe hyperthermia in dog.

PubMed

Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S

1983-01-01

The effect of acute hyperthermia on circulatory function was studied in 6 mongrel dogs. At a core temperature of about 40 degrees C, central venous pressure and stroke volume were maintained at almost normal level. Cardiac output significantly increased (26 ml/(kg . min)) while systemic vascular resistance significantly decreased (1.2 mmHg . sec/ml). In addition, significant decrease in vascular compliance by 40% was observed. When body temperature was raised further (severe hyperthermia), an abrupt fall of arterial pressure was observed at the rectal temperature of about 41-42 degrees C. Concomitant decreases in central venous pressure (3 mmHg), stroke volume (2.1 ml/beat) and cardiac output (29 ml/(kg . min)) were observed while heart rate increased (48 beats/min). These results suggest that the decrease in cardiac output during severe hyperthermia is due to the fall of central venous pressure, and the fall was attributed to the increase in unstressed vascular volume of systemic circulation due to the heat-induced cutaneous vasodilation. The observed decrease in systemic vascular compliance is considered to have a significant role in the maintenance of central venous pressure under hyperthermia.

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.

Selection of reference genes for gene expression studies in heart failure for left and right ventricles.

PubMed

Li, Mengmeng; Rao, Man; Chen, Kai; Zhou, Jianye; Song, Jiangping

2017-07-15

Real-time quantitative reverse transcriptase-PCR (qRT-PCR) is a feasible tool for determining gene expression profiles, but the accuracy and reliability of the results depends on the stable expression of selected housekeeping genes in different samples. By far, researches on stable housekeeping genes in human heart failure samples are rare. Moreover the effect of heart failure on the expression of housekeeping genes in right and left ventricles is yet to be studied. Therefore we aim to provide stable housekeeping genes for both ventricles in heart failure and normal heart samples. In this study, we selected seven commonly used housekeeping genes as candidates. By using the qRT-PCR, the expression levels of ACTB, RAB7A, GAPDH, REEP5, RPL5, PSMB4 and VCP in eight heart failure and four normal heart samples were assessed. The stability of candidate housekeeping genes was evaluated by geNorm and Normfinder softwares. GAPDH showed the least variation in all heart samples. Results also indicated the difference of gene expression existed in heart failure left and right ventricles. GAPDH had the highest expression stability in both heart failure and normal heart samples. We also propose using different sets of housekeeping genes for left and right ventricles respectively. The combination of RPL5, GAPDH and PSMB4 is suitable for the right ventricle and the combination of GAPDH, REEP5 and RAB7A is suitable for the left ventricle. Copyright © 2017 Elsevier B.V. All rights reserved.

Gaussian fitting for carotid and radial artery pressure waveforms: comparison between normal subjects and heart failure patients.

PubMed

Liu, Chengyu; Zheng, Dingchang; Zhao, Lina; Liu, Changchun

2014-01-01

It has been reported that Gaussian functions could accurately and reliably model both carotid and radial artery pressure waveforms (CAPW and RAPW). However, the physiological relevance of the characteristic features from the modeled Gaussian functions has been little investigated. This study thus aimed to determine characteristic features from the Gaussian functions and to make comparisons of them between normal subjects and heart failure patients. Fifty-six normal subjects and 51 patients with heart failure were studied with the CAPW and RAPW signals recorded simultaneously. The two signals were normalized first and then modeled by three positive Gaussian functions, with their peak amplitude, peak time, and half-width determined. Comparisons of these features were finally made between the two groups. Results indicated that the peak amplitude of the first Gaussian curve was significantly decreased in heart failure patients compared with normal subjects (P<0.001). Significantly increased peak amplitude of the second Gaussian curves (P<0.001) and significantly shortened peak times of the second and third Gaussian curves (both P<0.001) were also presented in heart failure patients. These results were true for both CAPW and RAPW signals, indicating the clinical significance of the Gaussian modeling, which should provide essential tools for further understanding the underlying physiological mechanisms of the artery pressure waveform.

Analysis of esophageal-sparing treatment plans for patients with high-grade esophagitis.

PubMed

Niedzielski, Joshua; Bluett, Jaques B; Williamson, Ryan T; Liao, Zhongxing; Gomez, Daniel R; Court, Laurence E

2013-07-08

We retrospectively generated IMRT plans for 14 NSCLC patients who had experienced grade 2 or 3 esophagitis (CTCAE version 3.0). We generated 11-beam and reduced esophagus dose plan types to compare changes in the volume and length of esophagus receiving doses of 50, 55, 60, 65, and 70 Gy. Changes in planning target volume (PTV) dose coverage were also compared. If necessary, plans were renormalized to restore 95% PTV coverage. The critical organ doses examined were mean lung dose, mean heart dose, and volume of spinal cord receiving 50 Gy. The effect of interfractional motion was determined by applying a three-dimensional rigid shift to the dose grid. For the esophagus plan, the mean reduction in esophagus V50, V55, V60, V65, and V70 Gy was 2.8, 4.1, 5.9, 7.3, and 9.5 cm(3), respectively, compared with the clinical plan. The mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 2.0, 3.0, 3.8, 4.0, and 4.6 cm, respectively. The mean heart and lung dose decreased 3.0 Gy and 2.4 Gy, respectively. The mean decreases in 90% and 95% PTV coverage were 1.7 Gy and 2.8 Gy, respectively. The normalized plans' mean reduction of esophagus V50, V55, V60, V65, and V70 Gy were 1.6, 2.0, 2.9, 3.9, and 5.5 cm(3), respectively, compared with the clinical plans. The normalized plans' mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 4.9, 5.2, 5.4, 4.9, and 4.8 cm, respectively. The mean reduction in maximum esophagus dose with simulated interfractional motion was 3.0 Gy and 1.4 Gy for the clinical plan type and the esophagus plan type, respectively. In many cases, the esophagus dose can be greatly reduced while maintaining critical structure dose constraints. PTV coverage can be restored by increasing beam output, while still obtaining a dose reduction to the esophagus and maintaining dose constraints.

Analysis of esophageal‐sparing treatment plans for patients with high‐grade esophagitis

PubMed Central

Bluett, Jaques B.; Williamson, Ryan T.; Liao, Zhongxing; Gomez, Daniel R.; Court, Laurence E.

2013-01-01

We retrospectively generated IMRT plans for 14 NSCLC patients who had experienced grade 2 or 3 esophagitis (CTCAE version 3.0). We generated 11‐beam and reduced esophagus dose plan types to compare changes in the volume and length of esophagus receiving doses of 50, 55, 60, 65, and 70 Gy. Changes in planning target volume (PTV) dose coverage were also compared. If necessary, plans were renormalized to restore 95% PTV coverage. The critical organ doses examined were mean lung dose, mean heart dose, and volume of spinal cord receiving 50 Gy. The effect of interfractional motion was determined by applying a three‐dimensional rigid shift to the dose grid. For the esophagus plan, the mean reduction in esophagus V50, V55, V60, V65, and V70 Gy was 2.8, 4.1, 5.9, 7.3, and 9.5 cm3, respectively, compared with the clinical plan. The mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 2.0, 3.0, 3.8, 4.0, and 4.6 cm, respectively. The mean heart and lung dose decreased 3.0 Gy and 2.4 Gy, respectively. The mean decreases in 90% and 95% PTV coverage were 1.7 Gy and 2.8 Gy, respectively. The normalized plans’ mean reduction of esophagus V50, V55, V60, V65, and V70 Gy were 1.6, 2.0, 2.9, 3.9, and 5.5 cm3, respectively, compared with the clinical plans. The normalized plans’ mean reductions in LE50, LE55, LE60, LE65, and LE70 Gy were 4.9, 5.2, 5.4, 4.9, and 4.8 cm, respectively. The mean reduction in maximum esophagus dose with simulated interfractional motion was 3.0 Gy and 1.4 Gy for the clinical plan type and the esophagus plan type, respectively. In many cases, the esophagus dose can be greatly reduced while maintaining critical structure dose constraints. PTV coverage can be restored by increasing beam output, while still obtaining a dose reduction to the esophagus and maintaining dose constraints. PACS number: 87.53 Tf PMID:23835390

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

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

Propafenone

MedlinePlus

... arrhythmia (irregular heartbeat) and to maintain a normal heart rate. Propafenone is in a class of medications called antiarrhythmics. It works by acting on the heart muscle to improve the heart's rhythm.

High Mid-Flow to Vital Capacity Ratio and the Response to Exercise in Children With Congenital Heart Disease.

PubMed

Vilozni, Daphna; Alcaneses-Ofek, Maria Rosario; Reuveny, Ronen; Rosenblum, Omer; Inbar, Omri; Katz, Uriel; Ziv-Baran, Tomer; Dubnov-Raz, Gal

2016-12-01

Pulmonary mechanics may play a role in exercise intolerance in patients with congenital heart disease (CHD). A reduced FVC volume could increase the ratio between mid-flow (FEF 25-75% ) and FVC, which is termed high dysanapsis. The relationship between high dysanapsis and the response to maximum-intensity exercise in children with CHD had not yet been studied. The aim of this work was to examine whether high dysanapsis is related to the cardiopulmonary response to maximum-intensity exercise in pediatric subjects with CHD. We retrospectively collected data from 42 children and adolescents with CHD who had either high dysanapsis (ratio >1.2; n = 21) or normal dysanapsis (control) (n = 21) as measured by spirometry. Data extracted from cardiopulmonary exercise test reports included peak values of heart rate, work load, V̇ O 2 , V̇ CO 2 , and ventilation parameters and submaximum values, including ventilatory threshold and ventilatory equivalents. There were no significant differences in demographic and clinical parameters between the groups. Participants with high dysanapsis differed from controls in lower median peak oxygen consumption (65.8% vs 83.0% of predicted, P = .02), peak oxygen pulse (78.6% vs 87.8% of predicted, P = .02), ventilatory threshold (73.8% vs 85.3% of predicted, P = .03), and maximum breathing frequency (106% vs 121% of predicted, P = .035). In the high dysanapsis group only, median peak ventilation and tidal volume were significantly lower than 80% of predicted values. In children and adolescents with corrected CHD, high dysanapsis was associated with a lower ventilatory capacity and reduced aerobic fitness, which may indicate respiratory muscle impairments. Copyright © 2016 by Daedalus Enterprises.

SU-E-T-125: Application of Jaw-Tracking Function in VMAT for Upper Thoracic Esophageal Cancer

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

Zhang, W; Chen, J; Zhai, T

2015-06-15

Purpose: To explore the effect of the Jaw-tracking with RapidArc(JT-RapidArc) plans for upper thoracic esophageal cancer. Methods: Treatment planning was designed by using RapidArc and JT-RapidArc techniques for 11 consecutive patients. The dose-volume histogram parameters of PTV and the organs at risk(OAR), conformity index(CI), heterogeneity index(HI), low dose volume of normal tissue(B-P) and monitor units(MUs) were compared between the different techniques. Results: JT-RapidArc plans provided the better coverage of PTV1(64) D98 and HI(P<0.05), lower MLD, D2 of PTV1(64) and PTV2(54), but no statistically difference in CI(P>0.05), which comparison with RapidArc plans. Plans with JT- RapidArc had lower Lung of V5,more » V10, V13, V20, V30, MLD(P<0.05); heart of V20, MLD(P<0.05); and B-P of V5, V10, V15, V20, V30(P<0.05); but no significantly different in Spinal cord and SC-PRV as compared with RapidArc plans. JT-RapidArc plans increaseed the MUs by 1%(P>0.05) as compared with RapidArc plans. Conclusion: All of the plans had met the requirements of clinical dosimetry. JT-RapidArc plans as compared with RapidArc plans, showing better part of target coverage, part of OARS(lung and heart) and heart and B-P sparing, which MUs was slightly increased. This work was sponsored by Shantou University Medical College Clinical Research Enhancement Initiative(NO.201424)« less

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.

Normalization of NAD+ Redox Balance as a Therapy for Heart Failure.

PubMed

Lee, Chi Fung; Chavez, Juan D; Garcia-Menendez, Lorena; Choi, Yongseon; Roe, Nathan D; Chiao, Ying Ann; Edgar, John S; Goo, Young Ah; Goodlett, David R; Bruce, James E; Tian, Rong

2016-09-20

Impairments of mitochondrial function in the heart are linked intricately to the development of heart failure, but there is no therapy for mitochondrial dysfunction. We assessed the reduced/oxidized ratio of nicotinamide adenine dinucleotide (NADH/NAD(+) ratio) and protein acetylation in the failing heart. Proteome and acetylome analyses were followed by docking calculation, mutagenesis, and mitochondrial calcium uptake assays to determine the functional role of specific acetylation sites. The therapeutic effects of normalizing mitochondrial protein acetylation by expanding the NAD(+) pool also were tested. Increased NADH/NAD(+) and protein hyperacetylation, previously observed in genetic models of defective mitochondrial function, also are present in human failing hearts as well as in mouse hearts with pathologic hypertrophy. Elevation of NAD(+) levels by stimulating the NAD(+) salvage pathway suppressed mitochondrial protein hyperacetylation and cardiac hypertrophy, and improved cardiac function in responses to stresses. Acetylome analysis identified a subpopulation of mitochondrial proteins that was sensitive to changes in the NADH/NAD(+) ratio. Hyperacetylation of mitochondrial malate-aspartate shuttle proteins impaired the transport and oxidation of cytosolic NADH in the mitochondria, resulting in altered cytosolic redox state and energy deficiency. Furthermore, acetylation of oligomycin-sensitive conferring protein at lysine-70 in adenosine triphosphate synthase complex promoted its interaction with cyclophilin D, and sensitized the opening of mitochondrial permeability transition pore. Both could be alleviated by normalizing the NAD(+) redox balance either genetically or pharmacologically. We show that mitochondrial protein hyperacetylation due to NAD(+) redox imbalance contributes to the pathologic remodeling of the heart via 2 distinct mechanisms. Our preclinical data demonstrate a clear benefit of normalizing NADH/NAD(+) imbalance in the failing hearts. These findings have a high translational potential as the pharmacologic strategy of increasing NAD(+) precursors are feasible in humans. © 2016 American Heart Association, Inc.

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.

In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

NASA Astrophysics Data System (ADS)

Nillesen, M. M.; Lopata, R. G. P.; de Boode, W. P.; Gerrits, I. H.; Huisman, H. J.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

2009-04-01

Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was validated quantitatively by comparing it with the CO values measured from the volume flow in the pulmonary artery. Relative bias varied between 0 and -17%, where the nominal accuracy of the flow meter is in the order of 10%. Assuming the CO measurements from the flow probe as a gold standard, excellent correlation (r = 0.99) was observed with the CO estimates obtained from image segmentation.

SU-E-P-47: Evaluation of Improvement of Esophagus Sparing in SBRT Lung Patients with Biologically Based IMRT Optimization

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

Liang, X; Penagaricano, J; Paudel, N

2015-06-15

Purpose: To study the potential of improving esophageal sparing for stereotactic body radiation therapy (SBRT) lung cancer patients by using biological optimization (BO) compared to conventional dose-volume based optimization (DVO) in treatment planning. Methods: Three NSCLC patients (PTV (62.3cc, 65.1cc, and 125.1cc) adjacent to the heart) previously treated with SBRT were re-planned using Varian Eclipse TPS (V11) using DVO and BO. The prescription dose was 60 Gy in 5 fractions normalized to 95% of the PTV volume. Plans were evaluated by comparing esophageal maximum doses, PTV heterogeneity (HI= D5%/D95%), and Paddick’s conformity (CI) indices. Quality of the plans was assessedmore » by clinically-used IMRT QA procedures. Results: By using BO, the maximum dose to the esophagus was decreased 1384 cGy (34.6%), 502 cGy (16.5%) and 532 cGy (16.2%) in patient 1, 2 and 3 respectively. The maximum doses to spinal cord and the doses to 1000 cc and 1500 cc of normal lung were comparable in both plans. The mean doses (Dmean-hrt) and doses to 15cc of the heart (V15-hrt) were comparable for patient 1 and 2. However for patient 3, with the largest PTV, Dmean-hrt and V15-hrt increased by 62.2 cGy (18.3%) and 549.9 cGy (24.9%) respectively for the BO plans. The mean target HI of BO plans (1.13) was inferior to the DVO plans (1.07). The same trend was also observed for mean CI in BO plans (0.77) versus DVO plans (0.83). The QA pass rates (3%, 3mm) were comparable for both plans. Conclusion: This study demonstrated that the use of biological models in treatment planning optimization can substantially improve esophageal sparing without compromising spinal cord and normal lung doses. However, for the large PTV case (125.1cc) we studied here, Dmean-hrt and V15-hrt increased substantially. The target HI and CI were inferior in the BO plans.« less

An Electromechanical Left Ventricular Wedge Model to Study the Effects of Deformation on Repolarization during Heart Failure

PubMed Central

Rocha, B. M.; Toledo, E. M.; Barra, L. P. S.; dos Santos, R. Weber

2015-01-01

Heart failure is a major and costly problem in public health, which, in certain cases, may lead to death. The failing heart undergo a series of electrical and structural changes that provide the underlying basis for disturbances like arrhythmias. Computer models of coupled electrical and mechanical activities of the heart can be used to advance our understanding of the complex feedback mechanisms involved. In this context, there is a lack of studies that consider heart failure remodeling using strongly coupled electromechanics. We present a strongly coupled electromechanical model to study the effects of deformation on a human left ventricle wedge considering normal and hypertrophic heart failure conditions. We demonstrate through a series of simulations that when a strongly coupled electromechanical model is used, deformation results in the thickening of the ventricular wall that in turn increases transmural dispersion of repolarization. These effects were analyzed in both normal and failing heart conditions. We also present transmural electrograms obtained from these simulations. Our results suggest that the waveform of electrograms, particularly the T-wave, is influenced by cardiac contraction on both normal and pathological conditions. PMID:26550570

Heart Valve Diseases

MedlinePlus

Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...

[Aortic valve insufficiency due to rupture of the cusp in a patient with multiple trauma].

PubMed

Vidmar, J; Brilej, D; Voga, G; Kovacic, N; Smrkolj, V

2003-06-01

Lesions of the heart valve caused by blunt chest trauma is rare, but when it does occur it can significantly injure the patient. On the basis of autopsy studies, research shows that heart valves are injured in less than 5% of patients who have died due to impact thoracic trauma. Among the heart valves, the aortic valve is the most often lacerated, which has been proved by relevant autopsy and clinical studies. Aortic valve lesions can be the only injury, but it is possible that additional heart or large vessel injuries are also present (myocardial contusion, rupture of the atrial septum, aortic rupture, rupture of the left common carotid artery). The force that causes such an injury is often great and often causes injuries to other organs and organ systems. In a multiple trauma patient, it is very important to specifically look for heart-related injuries because it is possible that they may be overlooked or missed by the surgeon, because of other obvious injuries. We describe the case of a 41-year-old man with multiple trauma who was diagnosed with aortic valve insufficiency due to rupture of the left coronary cusp 6 weeks after a road accident. Valvuloplasty was performed. Seven years later the patient is free of symptoms and is in good physical condition. Echocardiography showed normal dimensions of the heart chambers, a normal thickness of the heart walls, and normal systolic and diastolic function of the left ventricle. Heart valves are morphologically normal, and only an unimportant aortic insufficiency was noticed by echocardiography.

NADPH oxidase contributes to coronary endothelial dysfunction in the failing heart.

PubMed

Zhang, Ping; Hou, Mingxiao; Li, Yunfang; Xu, Xin; Barsoum, Michel; Chen, Yingjie; Bache, Robert J

2009-03-01

Increased reactive oxygen species (ROS) produced by the failing heart can react with nitric oxide (NO), thereby decreasing NO bioavailability. This study tested the hypothesis that increased ROS generation contributes to coronary endothelial dysfunction in the failing heart. Congestive heart failure (CHF) was produced in six dogs by ventricular pacing at 240 beats/min for 4 wk. Studies were performed at rest and during treadmill exercise under control conditions and after treatment with the NADPH oxidase inhibitor and antioxidant apocynin (4 mg/kg iv). Apocynin caused no significant changes in heart rate, aortic pressure, left ventricular (LV) systolic pressure, LV end-diastolic pressure, or maximum rate of LV pressure increase at rest or during exercise in normal or CHF dogs. Apocynin caused no change in coronary blood flow (CBF) in normal dogs but increased CBF at rest and during exercise in animals with CHF (P < 0.05). Intracoronary ACh caused dose-dependent increases of CBF that were blunted in CHF. Apocynin had no effect on the response to ACh in normal dogs but augmented the response to ACh in CHF dogs (P < 0.05). The oxidative stress markers nitrotyrosine and 4-hydroxy-2-nonenal were significantly greater in failing than in normal myocardium. Furthermore, coelenterazine chemiluminescence for O(2)(-) was more than twice normal in failing myocardium, and this difference was abolished by apocynin. Western blot analysis of myocardial lysates demonstrated that the p47(phox) and p22(phox) subunits of NADPH were significantly increased in the failing hearts, while real-time PCR demonstrated that Nox2 mRNA was significantly increased. The data indicate that increased ROS generation in the failing heart is associated with coronary endothelial dysfunction and suggest that NADPH oxidase may contribute to this abnormality.

Transabdominal amnioinfusion to avoid fetal demise and intestinal damage in fetuses with gastroschisis and severe oligohydramnios.

PubMed

Sapin, E; Mahieu, D; Borgnon, J; Douvier, S; Carricaburu, E; Sagot, P

2000-04-01

Despite dramatic improvement in survival rate for neonates with gastroschisis, significant postoperative morbidity and a low mortality rate still occur. Furthermore, even in recent publications, some fetal death has been reported. Does this mean that antenatal diagnosis of gastroschisis is a missed opportunity? In fact, decreased amniotic fluid (AF) volume is observed in some fetuses with gastroschisis. However, oligohydramnios is associated with an increased risk of fetal suffering. When severe oligohydramnios is observed, intrapartum amnioinfusion, to restore AF volume, may help avoid fetal complications. Two fetuses with gastroschisis and severe oligohydramnios were treated antenatally with amnioinfusion of saline solution. In one case, fetal heart beat decelerations were observed at 27 weeks' gestation among with the oligohydroamnios and serial transabdominal amnioinfusions were performed. In the second case, severe oligohydramnios was observed at 31, weeks and an amnioinfusion was performed. The 2 babies were delivered at 31 and 34 weeks, respectively. In both cases, exteriorized bowel was nearly normal at birth, and primary closure could be performed. Outcome was favorable, and they were discharged home on day 43 and day 54, respectively. Because fetuses with gastroschisis and oligohydramnios are part of a particular high-risk group, serial ultrasound examination and computerized fetal heart beat monitoring are necessary during the third trimester. In selected cases of gastroschisis associated with severe oligohydramnios, serial amnioinfusion may be required.

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

Excessively High Hydration Volume May Not Be Associated With Decreased Risk of Contrast-Induced Acute Kidney Injury After Percutaneous Coronary Intervention in Patients With Renal Insufficiency.

PubMed

Liu, Yong; Li, Hualong; Chen, Shiqun; Chen, Jiyan; Tan, Ning; Zhou, Yingling; Liu, Yuanhui; Ye, Piao; Ran, Peng; Duan, Chongyang; Chen, Pingyan

2016-05-27

No well-defined protocols currently exist regarding the optimal rate and duration of normal saline administration to prevent contrast-induced acute kidney injury (CI-AKI) in patients with renal insufficiency. Hydration volume ratios (hydration volume/weight; HV/W) were calculated in 1406 patients with renal insufficiency (estimated glomerular filtration rate [eGFR], <90 mL/min per 1.73 m(2)) undergoing percutaneous coronary intervention (PCI) with routine speed hydration (1 or 0.5 mL/kg per hour). We investigated the relationship between hydration volume, risk of CI-AKI (increase in serum creatinine ≥0.5 mg/dL or 25% within 48-72 hours), and prognosis. Mean follow-up duration was 2.85±0.88 years. Individuals with higher HV/W were more likely to develop CI-AKI (quartiles: Q1, Q2, Q3, and Q4: 4.3%, 6.6%, 10.9%, and 15.0%, respectively; P<0.001). After adjusting 12 confounders, including age, sex, eGFR, anemia, emergent PCI, diabetes mellitus, chronic heart failure, diuretics, contrast volume, lesions, smoking status, and number of stents, multivariate analysis showed that a higher HV/W ratio was not associated with a decreased CI-AKI risk (Q2 vs Q1: adjusted odds ratio [OR], 1.13; Q3 vs Q1: adjusted OR, 1.51; Q4 vs Q1: adjusted OR, 1.87; all P>0.05) and even increased CI-AKI risk (HV/W >25 mL/kg: adjusted OR, 2.11; 95% CI, 1.24-3.59; P=0.006). Additionally, higher HV/W was significantly associated with an increased risk of death (Q4 vs Q1: adjusted hazard ratio, 3.44; 95% CI, 1.20-9.88; P=0.022). Excessively high hydration volume at routine speed might be associated with increased risk of CI-AKI and death post-PCI in patients with renal insufficiency. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Esophageal cancer dose escalation using a simultaneous integrated boost technique.

PubMed

Welsh, James; Palmer, Matthew B; Ajani, Jaffer A; Liao, Zhongxing; Swisher, Steven G; Hofstetter, Wayne L; Allen, Pamela K; Settle, Steven H; Gomez, Daniel; Likhacheva, Anna; Cox, James D; Komaki, Ritsuko

2012-01-01

We previously showed that 75% of radiation therapy (RT) failures in patients with unresectable esophageal cancer are in the gross tumor volume (GTV). We performed a planning study to evaluate if a simultaneous integrated boost (SIB) technique could selectively deliver a boost dose of radiation to the GTV in patients with esophageal cancer. Treatment plans were generated using four different approaches (two-dimensional conformal radiotherapy [2D-CRT] to 50.4 Gy, 2D-CRT to 64.8 Gy, intensity-modulated RT [IMRT] to 50.4 Gy, and SIB-IMRT to 64.8 Gy) and optimized for 10 patients with distal esophageal cancer. All plans were constructed to deliver the target dose in 28 fractions using heterogeneity corrections. Isodose distributions were evaluated for target coverage and normal tissue exposure. The 50.4 Gy IMRT plan was associated with significant reductions in mean cardiac, pulmonary, and hepatic doses relative to the 50.4 Gy 2D-CRT plan. The 64.8 Gy SIB-IMRT plan produced a 28% increase in GTV dose and comparable normal tissue doses as the 50.4 Gy IMRT plan; compared with the 50.4 Gy 2D-CRT plan, the 64.8 Gy SIB-IMRT produced significant dose reductions to all critical structures (heart, lung, liver, and spinal cord). The use of SIB-IMRT allowed us to selectively increase the dose to the GTV, the area at highest risk of failure, while simultaneously reducing the dose to the normal heart, lung, and liver. Clinical implications warrant systematic evaluation. Copyright © 2012 Elsevier Inc. All rights reserved.

Esophageal Cancer Dose Escalation using a Simultaneous Integrated Boost Technique

PubMed Central

Welsh, James; Palmer, Matthew B.; Ajani, Jaffer A.; Liao, Zhongxing; Swisher, Steven G.; Hofstetter, Wayne L.; Allen, Pamela K.; Settle, Steven H.; Gomez, Daniel; Likhacheva, Anna; Cox, James D.; Komaki, Ritsuko

2014-01-01

Purpose We previously showed that 75% of radiation therapy (RT) failures in patients with unresectable esophageal cancer are in the gross tumor volume (GTV). We performed a planning study to evaluate if a simultaneous integrated boost (SIB) technique could selectively deliver a boost dose of radiation to the GTV in patients with esophageal cancer. Methods and Materials Treatment plans were generated using four different approaches (two-dimensional conformal RT [2D-CRT] to 50.4 Gy or 64.8 Gy, intensity-modulated RT [IMRT] to 50.4 Gy, and SIB-IMRT to 64.8 Gy) and optimized for 10 patients with distal esophageal cancer. All plans were constructed to deliver the target dose in 28 fractions using heterogeneity corrections. Isodose distributions were evaluated for target coverage and normal tissue exposure. Results The 50.4-Gy IMRT plan was associated with significant reductions in mean cardiac, pulmonary, and hepatic doses relative to the 50.4-Gy 2D-CRT plan. The 64.8-Gy SIB-IMRT plan produced a 28% increase in GTV dose and the same normal tissue doses as the 50.4-Gy IMRT plan; compared with the 50.4-Gy 2D-CRT plan, the 64.8-Gy SIB-IMRT produced significant dose reductions to all critical structures (heart, lung, liver, and spinal cord). Conclusions The use of SIB-IMRT allowed us to selectively increase the dose to the GTV, the area at highest risk of failure, while simultaneously reducing the dose to the normal heart, lung, and liver. Clinical implications warrant systematic evaluation. PMID:21123005

Inhibitors of soluble epoxide hydrolase minimize ischemia-reperfusion-induced cardiac damage in normal, hypertensive, and diabetic rats.

PubMed

Islam, Oliul; Patil, Prashanth; Goswami, Sumanta K; Razdan, Rema; Inamdar, Mohammed N; Rizwan, Mohammed; Mathew, Jubin; Inceoglu, Bora; Stephen Lee, Kin S; Hwang, Sung H; Hammock, Bruce D

2017-06-01

We designed a study to evaluate the cardioprotective effect of two soluble epoxide hydrolase (sEH) inhibitors, 1-(1-propanoylpiperidin-4-yl)-3-(4-trifluoromethoxy)phenyl)urea (TPPU) and trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]cyclohexyloxy}benzoic acid (t-TUCB), in ischemia-reperfusion (IR) model. Cardioprotective effects of the sEH inhibitors were evaluated against IR-induced myocardial damage in hearts from normal, hypertensive, and diabetic rats using Langendorff's apparatus. In addition, the effect of sEH inhibitors on endothelial function was evaluated in vitro and ex vivo using isolated rat thoracic aorta. Ischemia-reperfusion (IR) increased the myocardial damage in hearts from normal rats. IR-induced myocardial damage was augmented in hearts isolated from hypertensive and diabetic rats. Myocardial damage as evident from increase in the activities of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in heart perfusate was associated with significant decrease in the heart rate and developed tension, and increase in the resting tension in isolated heart. Both sEH inhibitors protected the heart in normal, hypertensive, and diabetic rats subjected to IR injury. The sEH inhibitor t-TUCB relaxed phenylephrine precontracted aorta from normal rats. Relaxant effect of acetylcholine (ACh) was reduced in aortas from diabetic and hypertensive rats compared to normal rats. Pretreatment of sEH inhibitors to diabetic and hypertensive rats increased relaxant effect of ACh on aortas isolated from these rats. Prophylactic treatment with sEH inhibitors decreased myocardial damage due to IR, hypertension and diabetes, and decreased endothelial dysfunction created by diabetes and hypertension. Therefore, inhibitors of sEH are useful probes to study cardiovascular pathology, and inhibition of the sEH is a potential approach in the management of IR-induced cardiac damage and endothelial dysfunction-related cardiovascular disorders. © 2017 John Wiley & Sons Ltd.

Cardiac remodelling in a baboon model of intrauterine growth restriction mimics accelerated ageing.

PubMed

Kuo, Anderson H; Li, Cun; Li, Jinqi; Huber, Hillary F; Nathanielsz, Peter W; Clarke, Geoffrey D

2017-02-15

Rodent models of intrauterine growth restriction (IUGR) successfully identify mechanisms that can lead to short-term and long-term detrimental cardiomyopathies but differences between rodent and human cardiac physiology and placental-fetal development indicate a need for models in precocial species for translation to human development. We developed a baboon model for IUGR studies using a moderate 30% global calorie restriction of pregnant mothers and used cardiac magnetic resonance imaging to evaluate offspring heart function in early adulthood. Impaired diastolic and systolic cardiac function was observed in IUGR offspring with differences between male and female subjects, compared to their respective controls. Aspects of cardiac impairment found in the IUGR offspring were similar to those found in normal controls in a geriatric cohort. Understanding early cardiac biomarkers of IUGR using non-invasive imaging in this susceptible population, especially taking into account sexual dimorphisms, will aid recognition of the clinical presentation, development of biomarkers suitable for use in humans and management of treatment strategies. Extensive rodent studies have shown that reduced perinatal nutrition programmes chronic cardiovascular disease. To enable translation to humans, we developed baboon offspring cohorts from mothers fed ad libitum (control) or 70% of the control ad libitum diet in pregnancy and lactation, which were growth restricted at birth. We hypothesized that intrauterine growth restriction (IUGR) offspring hearts would show impaired function and a premature ageing phenotype. We studied IUGR baboons (8 male, 8 female, 5.7 years), control offspring (8 male, 8 female, 5.6 years - human equivalent approximately 25 years), and normal elderly (OLD) baboons (6 male, 6 female, mean 15.9 years). Left ventricular (LV) morphology and systolic and diastolic function were evaluated with cardiac MRI and normalized to body surface area. Two-way ANOVA by group and sex (with P < 0.05) indicated ejection fraction, 3D sphericity indices, cardiac index, normalized systolic volume, normalized LV wall thickness, and average filling rate differed by group. Group and sex differences were found for normalized LV wall thickening and normalized myocardial mass, without interactions. Normalized peak LV filling rate and diastolic sphericity index were not correlated in control but strongly correlated in OLD and IUGR baboons. IUGR programming in baboons produces myocardial remodelling, reduces systolic and diastolic function, and results in the emergence of a premature ageing phenotype in the heart. To our knowledge, this is the first demonstration of the specific characteristics of cardiac programming and early life functional decline with ageing in an IUGR non-human primate model. Further studies across the life span will determine progression of cardiac dysfunction. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Flecainide

MedlinePlus

... of medications called antiarrhythmics. It works by slowing electrical signals in the heart to stabilize the heart ... if you have heart block (condition in which electrical signals are not passed normally from the upper ...

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...

Wavelet packet-based insufficiency murmurs analysis method

NASA Astrophysics Data System (ADS)

Choi, Samjin; Jiang, Zhongwei

2007-12-01

In this paper, the aortic and mitral insufficiency murmurs analysis method using the wavelet packet technique is proposed for classifying the valvular heart defects. Considering the different frequency distributions between the normal sound and insufficiency murmurs in frequency domain, we used two properties such as the relative wavelet energy and the Shannon wavelet entropy which described the energy information and the entropy information at the selected frequency band, respectively. Then, the signal to murmur ratio (SMR) measures which could mean the ratio between the frequency bands for normal heart sounds and for aortic and mitral insufficiency murmurs allocated to 15.62-187.50 Hz and 187.50-703.12 Hz respectively, were employed as a classification manner to identify insufficiency murmurs. The proposed measures were validated by some case studies. The 194 heart sound signals with 48 normal and 146 abnormal sound cases acquired from 6 healthy volunteers and 30 patients were tested. The normal sound signals recorded by applying a self-produced wireless electric stethoscope system to subjects with no history of other heart complications were used. Insufficiency murmurs were grouped into two valvular heart defects such as aortic insufficiency and mitral insufficiency. These murmur subjects included no other coexistent valvular defects. As a result, the proposed insufficiency murmurs detection method showed relatively very high classification efficiency. Therefore, the proposed heart sound classification method based on the wavelet packet was validated for the classification of valvular heart defects, especially insufficiency murmurs.

The Battle of "The Normal Heart."

ERIC Educational Resources Information Center

Rottman, Larry

1990-01-01

The history of the controversy over Southwest Missouri State University's production of "The Normal Heart," a play about acquired immune deficiency syndrome, is chronicled and concern is expressed about the resurgence of bitterness and hatred in the debate over academic freedom, even within the academic community. (MSE)

Internal associations and dynamic expression of c-kit and nanog genes in ventricular remodelling induced by adriamycin.

PubMed

Liu, Zhen; Li, Shuo; Liu, Lingling; Guo, Zhikun; Wang, Pengfei

2016-09-01

The present study aimed to investigate the dynamic expression of the c-kit and nanog genes in rats with left ventricular remodelling induced by adriamycin (ADR), and explore its internal association and mechanism of action. Sprague-Dawley male rats were randomly divided into a normal control group and a heart failure model group. Heart failure was induced by a single intraperitoneal injection of ADR (4 mg/kg) weekly for six weeks. The normal control group was given the same amount of saline. At the eighth week, rat cardiac function was examined to demonstrate the formation of heart failure. The rat hearts were harvested frozen and sectioned, and the expression levels of the nanog and c-kit genes in the myocardial tissue samples were detected using immunohistochemistry, immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). Hematoxylin and eosin staining demonstrated various pathological changes in the myocardial cells in the heart failure model group, whereas myocardial infarction was not observed in the normal control group. Immunohistochemistry and immunofluorescence demonstrated that nanog-positive cells were predominantly expressed in the vascular endothelium, with a few myocardial cells and stem cells in normal myocardium. The expression levels of c-kit and nanog in the myocardium of the rats with heart failure decreased significantly. c-kit-positive cells clustered together in the epicardium and its vicinity, and c-kit expression significantly decreased in the myocardium of rats with heart failure, as compared with normal rats. In both groups, some cells co-expressed both the c-kit and nanog genes. The RT-PCR results demonstrated that the expression levels of the two genes in the heart failure model group were significantly lower compared with those in the normal control group (P<0.05). In conclusion, the c-kit- and nanog-positive stem cells decreased in the myocardium of the rats with left ventricular remodelling induced by ADR. Their abnormal expression was significantly correlated with left ventricular remodelling, thereby indicating an internal association (influences of two indexes in the experimental group and control group) between them.

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.

Echocardiographic findings in stable outpatients with properly functioning HeartMate II left ventricular assist devices.

PubMed

Topilsky, Yan; Oh, Jae K; Atchison, Fawn W; Shah, Dipesh K; Bichara, Valentina M; Schirger, John A; Kushwaha, Sudhir S; Pereira, Naveen L; Park, Soon J

2011-02-01

Continuous-flow left ventricular assist devices (LVADs) have become part of the standard of care for the treatment of advanced heart failure. However, knowledge of normal values for transthoracic echocardiographic examination and measurements in these patients are lacking. All transthoracic echocardiographic examinations in 63 consecutive patients, performed 90 and 180 days after surgery with the implantation of a HeartMate II continuous-flow LVAD between February 2007 and January 2010, were retrospectively analyzed. All patients had to be outpatients at 3 and 6 months after surgery and considered stable on LVAD therapy (New York Heart Association class I or II and no need for inotropes, intravenous furosemide, or hospitalization). End-diastolic and end-systolic diameters and left ventricular mass decreased considerably compared with baseline measurements before LVAD implantation. Mitral inflow deceleration time increased (188 ± 70 vs 132.5 ± 27 msec, P = .009) and left atrial volume (84.1 ± 33 vs 141.7 ± 62 mL, P = .003) and E/e' ratio decreased (20.3 ± 9 vs 26 ± 11, P = .01), all consistent with decreased left ventricular filling pressure. Estimated right ventricular (RV) and right atrial pressure decreased significantly (34.1 ± 10 vs 51.7 ± 14 mm Hg and 9.5 ± 5 vs 14.4 ± 5 mm Hg, respectively, P < .0001 for both). Quantitatively estimated RV function (P = .02), RV fractional area change (27.9 ± 10% vs 37.4 ± 10.9%, P < .0001), and the RV index of myocardial performance (0.32 ± 0.1 vs 0.65 ± 0.2 vs 0.32 ± .01, P < .0001) improved, suggesting improved RV efficiency. LVAD therapy resulted in significant decreases in the severity of mitral regurgitation. Tricuspid regurgitation improved in patients who had concurrent tricuspid surgical correction and was unchanged otherwise. Aortic regurgitation severity increased 3 months after LVAD implantation. There were no significant differences in any of the echocardiographic parameters in the 6-month evaluation compared with the 3-month evaluation. This is the first report of selected typical echocardiographic values in a group of stable patients with normally functioning HeartMate II continuous-flow LVADs. A stable functioning continuous LVAD is associated with evidence of efficient unloading of the left ventricle, improved RV function, significant improvement in mitral regurgitation, improvement in tricuspid regurgitation only in patients undergoing repair, and increased aortic regurgitation. These normal data provide a basis for future echocardiographic studies after LVAD implantation. Copyright © 2011 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Prognostic Significance of Baseline Serum Sodium in Heart Failure With Preserved Ejection Fraction.

PubMed

Patel, Yash R; Kurgansky, Katherine E; Imran, Tasnim F; Orkaby, Ariela R; McLean, Robert R; Ho, Yuk-Lam; Cho, Kelly; Gaziano, J Michael; Djousse, Luc; Gagnon, David R; Joseph, Jacob

2018-06-13

The purpose of this study was to evaluate the relationship between serum sodium at the time of diagnosis and long term clinical outcomes in a large national cohort of patients with heart failure with preserved ejection fraction. We studied 25 440 patients with heart failure with preserved ejection fraction treated at Veterans Affairs medical centers across the United States between 2002 and 2012. Serum sodium at the time of heart failure diagnosis was analyzed as a continuous variable and in categories as follows: low (115.00-134.99 mmol/L), low-normal (135.00-137.99 mmol/L), referent group (138.00-140.99 mmol/L), high normal (141.00-143.99 mmol/L), and high (144.00-160.00 mmol/L). Multivariable Cox regression and negative binomial regression were performed to estimate hazard ratios (95% confidence interval [CI]) and incidence density ratios (95% CI) for the associations of serum sodium with mortality and hospitalizations (heart failure and all-cause), respectively. The average age of patients was 70.8 years, 96.2% were male, and 14% were black. Compared with the referent group, low, low-normal, and high sodium values were associated with 36% (95% CI, 28%-44%), 6% (95% CI, 1%-12%), and 9% (95% CI, 1%-17%) higher risk of all-cause mortality, respectively. Low and low-normal serum sodium were associated with 48% (95% CI, 10%-100%) and 38% (95% CI, 8%-77%) higher risk of number of days of heart failure hospitalizations per year, and with 44% (95% CI, 32%-56%) and 18% (95% CI, 10%-27%) higher risk of number of days of all-cause hospitalizations per year, respectively. Both elevated and reduced serum sodium, including values currently considered within normal range, are associated with adverse outcomes in patients with heart failure with preserved ejection fraction. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Dependence of Cardiac Systolic Function on Elevated Fatty Acid Availability in Obese, Insulin-Resistant Rats.

PubMed

Smith, Wayne; Norton, Gavin R; Woodiwiss, Angela J; Lochner, Amanda; du Toit, Eugene F

2016-07-01

Clinical data advocating an adverse effect of obesity on left ventricular (LV) systolic function independent of comorbidities is controversial. We hypothesized that in obesity with prediabetic insulin resistance, circulating fatty acids (FAs) become a valuable fuel source in the maintenance of normal systolic function. Male Wistar rats were fed a high caloric diet for 32 weeks to induce obesity. Myocardial LV systolic function was assessed using echocardiography and isolated heart preparations. Aortic output was reduced in obese rat hearts over a range of filling pressures (for example: 15 cmH2O, obese: 32.6 ± 1.2 ml/min vs control: 46.2 ± 0.9 ml/min, P < .05) when perfused with glucose alone. Similarly, the slope of the LV end-systolic pressure-volume relationship decreased, and there was a right shift in the LV end-systolic stress-strain relationship as determined in Langendorff perfused, isovolumic rat heart preparations in the presence of isoproterenol (10(-8)M) (LV systolic stress-strain relationship and a reduced load-independent intrinsic systolic myocardial function, obese: 791 ± 62 g/cm(2) vs control: 1186 ± 74 g/cm(2), P < .01). The addition of insulin to the perfusion buffer improved aortic output, whereas the addition of FAs completely normalized aortic output. LV function was maintained in obese animals in vivo during an inotropic challenge. Elevated circulating FA levels may be important to maintain myocardial systolic function in the initial stages of obesity and insulin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

Relevance of water gymnastics in rehabilitation programs in patients with chronic heart failure or coronary artery disease with normal left ventricular function.

PubMed

Teffaha, Daline; Mourot, Laurent; Vernochet, Philippe; Ounissi, Fawzi; Regnard, Jacques; Monpère, Catherine; Dugué, Benoit

2011-08-01

Exercise training is included in cardiac rehabilitation programs to enhance physical capacity and cardiovascular function. Among the existing rehabilitation programs, exercises in water are increasingly prescribed. However, it has been questioned whether exercises in water are safe and relevant in patients with stable chronic heart failure (CHF), coronary artery disease (CAD) with normal systolic left ventricular function. The goal was to assess whether a rehabilitation program, including water-based gymnastic exercises, is safe and induces at least similar benefits as a traditional land-based training. Twenty-four male CAD patients and 24 male CHF patients with stable clinical status participated in a 3-week rehabilitation. They were randomized to either a group performing the training program totally on land (CADl, CHFl; endurance + callisthenic exercises) or partly in water (CADw, CHFw; land endurance + water callisthenic exercises). Before and after rehabilitation, left ventricular systolic and cardiorespiratory functions, hemodynamic variables and autonomic nervous activities were measured. No particular complications were associated with both of our programs. At rest, significant improvements were seen in CHF patients after both types of rehabilitation (increases in stroke volume and left ventricular ejection fraction [LVEF]) as well as a decrease in heart rate (HR) and in diastolic arterial pressure. Significant increases in peaks VO(2), HR, and power output were observed in all patients after rehabilitation in exercise test. The increase in LVEF at rest, in HR and power output at the exercise peak were slightly higher in CHFw than in CHFl. Altogether, both land and water-based programs were well tolerated and triggered improvements in cardiorespiratory function. Copyright © 2011 Elsevier Inc. All rights reserved.

The prevalence and character of crackles (rales) in young women without significant lung disease.

PubMed

Workum, P; Holford, S K; Delbono, E A; Murphy, R L

1982-11-01

Although some investigators have reported that crackles are present only in persons with lung disease, others say they also occur in normal persons. In order to clarify this difference of opinion, we determined the prevalence of crackles in 56 women without significant lung disease. The subjects ranged from 19 to 33 yr of age (mean, 21.3). They all had a FVC greater than 80% predicted and a FEV1/FVC ratio greater than 75%. None had a history of acute or chronic lung disease. During slow inspirations from residual volume, midinspiratory fine crackles were heard at the anterior bases in 35 of 56 subjects by a physician using an acoustic stethoscope, whereas a bioengineer using an 800 Hertz high pass filtered stethoscope heard crackles in 53 subjects. Crackles during tidal breathing were heard in 2 subjects. It is postulated that the crackles noted after expiration to residual volume are nonpathologic, and occur when basilar airways, which close at the end of a forced expiration, suddenly open during inspiration. Examination of the quality, timing, and anatomic distribution of the crackles in apparently normal subjects suggests that they can often be distinguished from those resulting from diseases such as bronchitis, interstitial fibrosis, and congestive heart failure.

Iodine-123 metaiodobenzylguanidine imaging of the heart in idiopathic congestive cardiomyopathy and cardiac transplants

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

Glowniak, J.V.; Turner, F.E.; Gray, L.L.

1989-07-01

Iodine-123 metaiodobenzylguanidine ((/sup 123/I)MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with (/sup 123/I)MIBG was performed in patients with idiopathic congestive cardiomyopathy and compared to normal controls. Initial uptake, half-time of tracer within the heart, and heart to lung ratios were all significantly reduced in patients compared to normals. Uptake in lungs, liver, salivary glands, and spleen was similar in controls and patients with cardiomyopathy indicating that decreased MIBG uptake was not a generalized abnormality in these patients. Iodine-123 MIBG imaging was also performed in cardiacmore » transplant patients to determine cardiac nonneuronal uptake. Uptake in transplants was less than 10% of normals in the first 2 hr and nearly undetectable after 16 hr. The decreased uptake of MIBG suggests cardiac sympathetic nerve dysfunction while the rapid washout of MIBG from the heart suggests increased cardiac sympathetic nerve activity in idiopathic congestive cardiomyopathy.« less

Complete inhibition of creatine kinase in isolated perfused rat hearts

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

Fossel, E.T.; Hoefeler, H.

1987-01-01

Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts aremore » able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. /sup 31/P-NMR of the heart was carried out.« less

Detection of a Heart Defect in the Fetus

MedlinePlus

... problems : There is a wide range of acceptable fetal heart rates (normal is between 120 and 160 but many ... usually go away shortly after birth. More important fetal heart problems include tachycardia (hear rate too fast) and bradycardia (heart rate too slow). ...

Aging changes in the heart and blood vessels

MedlinePlus

Heart disease - aging; Atherosclerosis - aging ... Some changes in the heart and blood vessels normally occur with age. However, many other changes that are common with aging are due to modifiable ...

[Improvement in functional capacity after levothyroxine treatment in patients with chronic heart failure and subclinical hypothyroidism].

PubMed

Curotto Grasiosi, Jorge; Peressotti, Bruno; Machado, Rogelio A; Filipini, Eduardo C; Angel, Adriana; Delgado, Jorge; Cortez Quiroga, Gustavo A; Rus Mansilla, Carmen; Martínez Quesada, María del Mar; Degregorio, Alejandro; Cordero, Diego J; Dak, Marcelo; Izurieta, Carlos; Esper, Ricardo J

2013-10-01

To assess whether levothyroxine treatment improves functional capacity in patients with chronic heart failure (New York Heart Association class i-iii) and subclinical hypothyroidism. One hundred and sixty-three outpatients with stable chronic heart failure followed up for at least 6 months were enrolled. A physical examination was performed, and laboratory tests including thyroid hormone levels, Doppler echocardiogram, radionuclide ventriculography, and Holter monitoring were requested. Functional capacity was assessed by of the 6-min walk test. Patients with subclinical hypothyroidism were detected and, after undergoing the s6-min walk test, were given replacement therapy. When they reached normal thyrotropin (TSH) levels, the 6-min walk test was performed again. The distance walked in both tests was recorded, and the difference in meters covered by each patient was analyzed. Prevalence of subclinical hypothyroidism in patients with heart failure was 13%. These patients walked 292±63m while they were hypothyroid and 350±76m when TSH levels returned to normal, a difference of 58±11m (P<.011). Patients with normal baseline TSH levels showed no significant difference between the 2 6-min walk tests. Patients with chronic heart failure and subclinical hypothyroidism significantly improved their physical performance when normal TSH levels were reached. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

An Evaluation of the Ability of Navy Hospital Corpsmen to Collect Chest Pain Data from Patients

DTIC Science & Technology

1984-01-11

PREVIOUS CARDIO-RESPIRATOFJY ILLNESS: (significant illenss either cardiovascular or respiratory ) YES (64) NO (65) PREVIOUS MAJOR SURGERY...clavicle to chin - elevated) otherwise circle normal) NORMAL (97) RAISED (98) RESPIRATORY MOVEMENT: (abnormal = the difference between...ABNORMAL (100) HEART SOUNDS: (with a stethoscope listen to the 1st and 2nd heart sounds; normal - lub-dub, lub-dub; abnormal " everything else

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

Investigating alcohol-induced congenital heart defects using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gu, Shi; Peterson, Lindsy M.; Ma, Pei; Karunamuni, Ganga; Watanabe, Michiko; Jenkins, Michael W.; Rollins, Andrew M.

2016-03-01

Fetal alcohol syndrome commonly results in neurological and craniofacial defects, additionally, as high as 54% of live-born children with this syndrome also possess cardiac abnormalities. We have previously shown that CNCC-ablated embryos exhibit similar structural and functional phenotypes as ethanol-exposed embryos. Here, we present progress on two fronts toward understanding the association between CNCC dysfunction and FAS-related CHDs. We have developed a technique for measuring the thickness of the cardiac cushions throughout the heart. These values were then mapped onto a surface mesh of the myocardial wall for 3-D visualization. The cushions were observed to be significantly reduced in the outflow tract of CNCC-ablated embryos. We also observed a correlation between abnormal pulsed Doppler waveforms and increased separation of the atrioventricular inferior and superior cushions. This correlation between function and structure will enable rapid phenotyping of perturbed embryos. Finally, we present our preliminary results using methyl donors to rescue ethanol-exposed embryonic CHDs. Betaine was administered along with the ethanol injection to embryos at 21 hours of development. The embryos were then analyzed at day 8 for survival and heart morphology. The administration of betaine resulted in a significant increase in survival and normalization of atrioventricular valve leaflet volume and interventricular septum thickness.

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.

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.

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

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.

Teaching Recognition of Normal and Abnormal Heart Sounds Using Computer-Assisted Instruction

ERIC Educational Resources Information Center

Musselman, Eugene E.; Grimes, George M.

1976-01-01

The computer is being used in an innovative manner to teach the recognition of normal and abnormal canine heart sounds at the University of Chicago. Experience thus far indicates that the PLATO program resources allow the maximum development of the student's proficiency in auscultation. (Editor/LBH)

Effects of far infrared rays irradiated from ceramic material (BIOCERAMIC) on psychological stress-conditioned elevated heart rate, blood pressure, and oxidative stress-suppressed cardiac contractility.

PubMed

Leung, Ting-Kai; Chen, Chien-Ho; Tsai, Shih-Ying; Hsiao, George; Lee, Chi-Ming

2012-10-31

The present study examined the effects of BIOCERAMIC on psychological stress-conditioned elevated heart rate, blood pressure and oxidative stress-suppressed cardiac contractility using in vivo and in vitro animal models. We investigated the effects of BIOCERAMIC on the in vivo cardiovascular hemodynamic parameters of rats by monitoring their heart rates, systolic blood pressure, mean blood pressure and diastolic blood pressure. Thereafter, we assayed its effects on the heart rate in an isolated frog heart with and without adrenaline stimulation, and on cardiac contractility under oxidative stress. BIOCERAMIC caused significant decreases in heart rates and systolic and mean blood pressure in the stress-conditioned heart rate rat models (P < 0.05), as well as in the experimental models of an isolated frog heart with and without adrenaline stimulation (P < 0.05), and normalized cardiac contractility under oxidative stress (P < 0.05). BIOCERAMIC may, therefore, normalize the effects of psychological stress and oxidative stress conditions.

Heart rates increase after hatching in two species of natricine snakes

PubMed Central

Aubret, Fabien

2013-01-01

Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits. PMID:24287712

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.

Hemodynamic adaptation to suboptimal fetal growth in patients with single ventricle physiology.

PubMed

Alsaied, Tarek; Tseng, Stephanie; King, Eileen; Hahn, Eunice; Divanovic, Allison; Habli, Mounira; Cnota, James

2018-06-10

In fetuses with structurally normal heart and suboptimal fetal growth (SFG), umbilical artery vascular resistance increases as measured by umbilical artery pulsatility index (UA-PI). The objective of this study is to compare hemodynamic responses to SFG in fetuses with single ventricle (SV) and controls with structurally normal heart. Fetal echocardiograms around 30 weeks of gestation were reviewed. UA-PI and middle cerebral artery pulsatility index (MCA-PI) were calculated. SFG was defined as a birth weight below 25th percentile for gestational age. Studies from 92 fetuses were reviewed-SV (n = 50) and controls (n = 42). The prevalence of SFG was higher in SV compared to controls (46% vs 21%, P = .02). In patients with normal heart and SFG, UAPI was significantly higher than normal controls (P = .003) suggesting increased placental vascular resistance. In SV with SFG there was no difference in UAPI compared to SV without SFG. There was no difference in MCA-PI between the groups. The hemodynamic response to SFG in SV varies from fetuses with structurally normal heart. The mechanism of SFG and the placental pathology may be distinct in SV. © 2018 Wiley Periodicals, Inc.

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.

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.

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-lung transplant - slideshow

MedlinePlus

... page: //medlineplus.gov/ency/presentations/100147.htm Heart-lung transplant - series—Normal anatomy To use the sharing features ... Editorial team. Related MedlinePlus Health Topics Heart Transplantation Lung Transplantation A.D.A.M., Inc. is accredited by ...

Heart failure - home monitoring

MedlinePlus

... you lose a lot of weight. Checking Your Heart Rate and Pulse Know what your normal pulse rate ... may give you special equipment to check your heart rate. Checking Your Blood Pressure Your provider may ask ...

Effect of suprachiasmatic lesions on diurnal heart rate rhythm in the rat

NASA Technical Reports Server (NTRS)

Saleh, M. A.; Winget, C. M.

1977-01-01

Heart rate and locomotor activity of rats kept under 12L/12D illumination regimen were recorded every six minutes for ten days using implantable radio transmitters. Some of the rats then received bilateral RF lesions into the suprachiasmatic nucleus (SCN). Control sham operations were performed on the rest of the animals. After recovery from surgery, recording of heart rate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heart rate, while normal and sham-operated rats showed the normal diurnal rhythm in that function. The arrhythmic diurnal heart-rate pattern of SCN rats appeared to be correlated with their sporadic activity pattern. The integrity of the suprachiasmatic nucleus is therefore necessary for the generation and/or expression of diurnal rhythmicity in heart rate in the rat.

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)

White Matter Volume Predicts Language Development in Congenital Heart Disease

PubMed Central

Rollins, Caitlin K.; Asaro, Lisa A.; Akhondi-Asl, Alireza; Kussman, Barry D.; Rivkin, Michael J.; Bellinger, David C.; Warfield, Simon K.; Wypij, David; Newburger, Jane W.; Soul, Janet S.

2016-01-01

Objective To determine whether brain volume is reduced at one year and whether these volumes are associated with neurodevelopment in biventricular congenital heart disease (CHD) repaired in infancy. Study design Infants with biventricular CHD (n = 48) underwent brain magnetic resonance imaging (MRI) and neurodevelopmental testing with the Bayley Scales of Infant Development-II (BSID-II) and the MacArthur-Bates Communicative Development Inventories (CDI) at one year. A multi-template based probabilistic segmentation algorithm was applied to volumetric MRI data. We compared volumes with those of 13 healthy control infants of comparable ages. In the CHD group, we measured Spearman correlations between neurodevelopmental outcomes and the residuals from linear regression of the volumes on corrected chronological age at MRI and sex. Results Compared with controls, CHD infant had reductions of 54 mL in total brain (P = 0.009), 40 mL in cerebral white matter (P < 0.001), and 1.2 mL in brainstem (P = 0.003) volumes. Within the CHD group, brain volumes were not correlated with BSID-II scores but did correlate positively with CDI language development. Conclusion Infants with biventricular CHD show total brain volume reductions at one year of age, driven by differences in cerebral white matter. White matter volume correlates with language development, but not broader developmental indices. These findings suggest that abnormalities in white matter development detected months after corrective heart surgery may contribute to language impairment. Trial registration ClinicalTrials.gov: NCT00006183 PMID:27837950

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.

Collagen birefringence assessment in heart chordae tendineae through PS-OCT

NASA Astrophysics Data System (ADS)

Real, Eusebio; Revuelta, José M.; González-Vargas, Nieves; Pontón, Alejandro; Calvo-Díez, Marta; López-Higuera, José M.; Conde, Olga M.

2017-02-01

Degenerative mitral regurgitation is a serious and frequent human heart valve disease. Malfunctioning of this valve brings the left-sided heart through a significant increase of pressure and volume overload. Severe degenerative mitral incompetence generally requires surgical repair or valve replacement with a bioprosthesis or mechanical heart valve. Degenerative disease affects the leaflets or/and the chordae tendineae, which link both leaflets to the papillary muscles. During mitral valve surgical repair, reconstruction of the valve leaflets, annulus and chordae are provided to prevent postoperative recurrence of valve regurgitation. The operative evaluation of the diseased and apparently normal chordae tendineae mainly depends of the surgeońs experience, without any other objective diagnosis tool. In this work, PS-OCT (Polarization Sensitive-Optical Coherence Tomography) is applied for the first time to evaluate the pathological condition of human chordae coming from the mitral valve. It consists on a prospective study to test the viability of this technique for the evaluation of the collagen core of chords. This core presents a strong birefringence due to the longitudinal and organized arrangement of its collagen bundles. Different densities and organizations of the collagen core translate into different birefringence indicators whose measurement become an objective marker of the core structure. Ex-vivo mitral degenerative chordae tendineae have been analyzed with PS-OCT. Intensity OCT is used to obtain complementary morphological information of the chords. Birefringence results correlate with the previously reported values for human tendinous tissue.

Hyaluronidase 2 Deficiency Causes Increased Mesenchymal Cells, Congenital Heart Defects, and Heart Failure.

PubMed

Chowdhury, Biswajit; Xiang, Bo; Liu, Michelle; Hemming, Richard; Dolinsky, Vernon W; Triggs-Raine, Barbara

2017-01-01

Hyaluronan (HA) is required for endothelial-to-mesenchymal transition and normal heart development in the mouse. Heart abnormalities in hyaluronidase 2 (HYAL2)-deficient ( Hyal2 - /- ) mice and humans suggested removal of HA is also important for normal heart development. We have performed longitudinal studies of heart structure and function in Hyal2 -/- mice to determine when, and how, HYAL2 deficiency leads to these abnormalities. Echocardiography revealed atrial enlargement, atrial tissue masses, and valvular thickening at 4 weeks of age, as well as diastolic dysfunction that progressed with age, in Hyal2 -/- mice. These abnormalities were associated with increased HA, vimentin-positive cells, and fibrosis in Hyal2 -/- compared with control mice. Based on the severity of heart dysfunction, acute and chronic groups of Hyal2 -/- mice that died at an average of 12 and 25 weeks respectively, were defined. Increased HA levels and mesenchymal cells, but not vascular endothelial growth factor in Hyal2 -/- embryonic hearts, suggest that HYAL2 is important to inhibit endothelial-to-mesenchymal transition. Consistent with this, in wild-type embryos, HYAL2 and HA were readily detected, and HA levels decreased with age. These data demonstrate that disruption of normal HA catabolism in Hyal2 -/- mice causes increased HA, which may promote endothelial-to-mesenchymal transition and proliferation of mesenchymal cells. Excess endothelial-to-mesenchymal transition, resulting in increased mesenchymal cells, is the likely cause of morphological heart abnormalities in both humans and mice. In mice, these abnormalities result in progressive and severe diastolic dysfunction, culminating in heart failure. © 2016 The Authors.

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.

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.

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.

Content validation of the operational definitions of the nursing diagnoses of activity intolerance, excess fluid volume, and decreased cardiac output in patients with heart failure.

PubMed

de Souza, Vanessa; Zeitoun, Sandra Salloum; Lopes, Camila Takao; de Oliveira, Ana Paula Dias; Lopes, Juliana de Lima; de Barros, Alba Lucia Botura Leite

2014-06-01

To consensually validate the operational definitions of the nursing diagnoses activity intolerance, excessive fluid volume, and decreased cardiac output in patients with decompensated heart failure. Consensual validation was performed in two stages: analogy by similarity of defining characteristics, and development of operational definitions and validation with experts. A total of 38 defining characteristics were found. Operational definitions were developed and content-validated. One hundred percent of agreement was achieved among the seven experts after five rounds. "Ascites" was added in the nursing diagnosis excessive fluid volume. The consensual validation improves interpretation of human response, grounding the selection of nursing interventions and contributing to improved nursing outcomes. Support the assessment of patients with decompensated heart failure. © 2013 NANDA International.

Right Heart Vortex Entrainment Volume and Right Ventricular Diastolic Dysfunction

NASA Astrophysics Data System (ADS)

Browning, James; Hertzberg, Jean; Fenster, Brett; Schroeder, Joyce

2014-11-01

Recent advances in cardiac magnetic resonance imaging (CMR) have allowed for the 3-dimensional characterization of blood flow in the right ventricle (RV) and right atrium (RA). In this study, we investigate and quantify differences in the characteristics of coherent rotating flow structures (vortices) in the RA and RV between subjects with right ventricular diastolic dysfunction (RVDD) and normal controls. Fifteen RVDD subjects and 10 age-matched controls underwent same day 3D time resolved CMR and echocardiography. Echocardiography was used to determine RVDD stage as well as pulmonary artery systolic pressure (PASP). CMR data was used for RA and RV vortex quantification and visualization during early and late ventricular diastole. RA and RV vortex entrainment volume is quantified and visualized using the Lambda-2 criterion, and the results are compared between healthy subjects and those with RVDD. The resulting trends are discussed and hypotheses are presented regarding differences in vortex characteristics between healthy and RVDD subjects cohorts.

Decrease of cardiac chaos in congestive heart failure

NASA Astrophysics Data System (ADS)

Poon, Chi-Sang; Merrill, Christopher K.

1997-10-01

The electrical properties of the mammalian heart undergo many complex transitions in normal and diseased states. It has been proposed that the normal heartbeat may display complex nonlinear dynamics, including deterministic chaos,, and that such cardiac chaos may be a useful physiological marker for the diagnosis and management, of certain heart trouble. However, it is not clear whether the heartbeat series of healthy and diseased hearts are chaotic or stochastic, or whether cardiac chaos represents normal or abnormal behaviour. Here we have used a highly sensitive technique, which is robust to random noise, to detect chaos. We analysed the electrocardiograms from a group of healthy subjects and those with severe congestive heart failure (CHF), a clinical condition associated with a high risk of sudden death. The short-term variations of beat-to-beat interval exhibited strongly and consistently chaotic behaviour in all healthy subjects, but were frequently interrupted by periods of seemingly non-chaotic fluctuations in patients with CHF. Chaotic dynamics in the CHF data, even when discernible, exhibited a high degree of random variability over time, suggesting a weaker form of chaos. These findings suggest that cardiac chaos is prevalent in healthy heart, and a decrease in such chaos may be indicative of CHF.

Ventricular myoarchitecture in tetralogy of Fallot.

PubMed Central

Sanchez-Quintana, D.; Anderson, R. H.; Ho, S. Y.

1996-01-01

BACKGROUND: Little attention has been paid to the architecture of the muscle fibres of the ventricular walls in congenitally malformed hearts. In this study the gross pattern of myocardial fibres in normal hearts was compared with that in cases of tetralogy of Fallot. METHODS AND RESULTS: After morphological examination nine specimens with tetralogy were dissected to study the ventricular myoarchitecture. Changes were found in the shape of the malformed ventricles. The ventricular walls were arranged in layers in all hearts. Superficial and deep layers were present in both ventricles, with the superficial layer showing a more oblique orientation in the specimens with tetralogy than in normal hearts. Modifications of muscle fibre that were related to the type of malformation were seen in the deep layer. A middle layer was present in the left ventricles of normal hearts and specimens with tetralogy: this showed a horizontal orientation in both groups. In contrast, a middle layer was found in the right ventricle only in specimens showing tetralogy. CONCLUSIONS: The malformed hearts showed modifications in ventricular shape, in the arrangement of muscle in the right ventricle, and in the overall myoarchitecture. These changes could well be the consequence of the same agent (or agents) that caused the structural defect. Images PMID:8868990

Mössbauer Spectra of Mouse Hearts Reveal Age-dependent Changes in Mitochondrial and Ferritin Iron Levels.

PubMed

Wofford, Joshua D; Chakrabarti, Mrinmoy; Lindahl, Paul A

2017-03-31

Cardiac function requires continuous high levels of energy, and so iron, a critical player in mitochondrial respiration, is an important component of the heart. Hearts from 57 Fe-enriched mice were evaluated by Mössbauer spectroscopy. Spectra consisted of a sextet and two quadrupole doublets. One doublet was due to residual blood, whereas the other was due to [Fe 4 S 4 ] 2+ clusters and low-spin Fe II hemes, most of which were associated with mitochondrial respiration. The sextet was due to ferritin; there was no evidence of hemosiderin, a ferritin decomposition product. Iron from ferritin was nearly absent in young hearts, but increased steadily with age. EPR spectra exhibited signals similar to those of brain, liver, and human cells. No age-dependent EPR trends were apparent. Hearts from HFE -/- mice with hemochromatosis contained slightly more iron overall than controls, including more ferritin and less mitochondrial iron; these differences typify slightly older hearts, perhaps reflecting the burden due to this disease. HFE -/- livers were overloaded with ferritin but had low mitochondrial iron levels. IRP2 -/- hearts contained less ferritin than controls but normal levels of mitochondrial iron. Hearts of young mice born to an iron-deficient mother contained normal levels of mitochondrial iron and no ferritin; the heart from the mother contained low ferritin and normal levels of mitochondrial iron. High-spin Fe II ions were nearly undetectable in heart samples; these were evident in brains, livers, and human cells. Previous Mössbauer spectra of unenriched diseased human hearts lacked mitochondrial and blood doublets and included hemosiderin features. This suggests degradation of iron-containing species during sample preparation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Obesity and synergistic risk factors for chronic kidney disease in African American adults: the Jackson Heart Study.

PubMed

Olivo, Robert E; Davenport, Clemontina A; Diamantidis, Clarissa J; Bhavsar, Nrupen A; Tyson, Crystal C; Hall, Rasheeda; Bidulescu, Aurelian; Young, Bessie; Mwasongwe, Stanford E; Pendergast, Jane; Boulware, L Ebony; Scialla, Julia J

2017-08-30

African Americans are at high risk for chronic kidney disease (CKD). Obesity may increase the risk for CKD by exacerbating features of the metabolic syndrome and promoting glomerular hyperfiltration. Whether other factors also affecting these pathways may amplify or mitigate obesity-CKD associations has not been investigated. We studied interactions between obesity and these candidate factors in 2043 African Americans without baseline kidney disease enrolled in the Jackson Heart Study. We quantified obesity as body mass index (BMI), sex-normalized waist circumference and visceral adipose volume measured by abdominal computed tomography at an interim study visit. Interactions were hypothesized with (i) metabolic risk factors (dietary quality and physical activity, both quantified by concordance with American Heart Association guidelines) and (ii) factors exacerbating or mitigating hyperfiltration (dietary protein intake, APOL1 risk status and use of renin-angiotensin system blocking medications). Using multivariable regression, we evaluated associations between obesity measures and incident CKD over the follow-up period, as well as interactions with metabolic and hyperfiltration factors. Assessed after a median of 8 years (range 6-11 years), baseline BMI and waist circumference were not associated with incident CKD. Higher visceral adipose volume was independently associated with incident CKD (P   =   0.008) in a nonlinear fashion, but this effect was limited to those with lower dietary quality (P   =   0.001; P-interaction = 0.04). In additional interaction models, higher waist circumference was associated with greater risk of incident CKD among those with the low-risk APOL1 genotype (P   =   0.04) but not those with a high-risk genotype (P-interaction = 0.02). Other proposed factors did not modify obesity-CKD associations. Higher risks associated with metabolically active visceral adipose volume and interactions with dietary quality suggest that metabolic factors may be key determinants of obesity-associated CKD risk. Interactions between obesity and APOL1 genotype should be considered in studies of African Americans. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Transjugular intrahepatic portosystemic shunt: impact on systemic hemodynamics and renal and cardiac function in patients with cirrhosis.

PubMed

Busk, Troels M; Bendtsen, Flemming; Poulsen, Jørgen H; Clemmesen, Jens O; Larsen, Fin S; Goetze, Jens P; Iversen, Jens S; Jensen, Magnus T; Møgelvang, Rasmus; Pedersen, Erling B; Bech, Jesper N; Møller, Søren

2018-02-01

Transjugular intrahepatic portosystemic shunt (TIPS) alleviates portal hypertension and possibly increases central blood volume (CBV). Moreover, renal function often improves; however, its effects on cardiac function are unclear. The aims of our study were to examine the effects of TIPS on hemodynamics and renal and cardiac function in patients with cirrhosis. In 25 cirrhotic patients, we analyzed systemic, cardiac, and splanchnic hemodynamics by catheterization of the liver veins and right heart chambers before and 1 wk after TIPS. Additionally, we measured renal and cardiac markers and performed advanced echocardiography before, 1 wk after, and 4 mo after TIPS. CBV increased significantly after TIPS (+4.6%, P < 0.05). Cardiac output (CO) increased (+15.3%, P < 0.005) due to an increase in stroke volume (SV) (+11.1%, P < 0.005), whereas heart rate (HR) was initially unchanged. Cardiopulmonary pressures increased after TIPS, whereas copeptin, a marker of vasopressin, decreased (-18%, P < 0.005) and proatrial natriuretic peptide increased (+52%, P < 0.0005) 1 wk after TIPS and returned to baseline 4 mo after TIPS. Plasma neutrophil gelatinase-associated lipocalin, renin, aldosterone, and serum creatinine decreased after TIPS (-36%, P < 0.005; -65%, P < 0.05; -90%, P < 0.005; and -13%, P < 0.005, respectively). Echocardiography revealed subtle changes in cardiac function after TIPS, although these were within the normal range. TIPS increases CBV by increasing CO and SV, whereas HR is initially unaltered. These results indicate an inability to increase the heart rate in response to a hemodynamic challenge that only partially increases CBV after TIPS. These changes, however, are sufficient for improving renal function. NEW & NOTEWORTHY For the first time, we have combined advanced techniques to study the integrated effects of transjugular intrahepatic portosystemic shunt (TIPS) in cirrhosis. We showed that TIPS increases central blood volume (CBV) through improved cardiac inotropy. Advanced echocardiography demonstrated that myocardial function was unaffected by the dramatic increase in preload after TIPS. Finally, renal function improved due to the increase in CBV. Recognition of these physiological changes significantly contributes to our clinical understanding of TIPS.

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.

Gender differences and normal left ventricular anatomy in an adult population free of hypertension. A cardiovascular magnetic resonance study of the Framingham Heart Study Offspring cohort.

PubMed

Salton, Carol J; Chuang, Michael L; O'Donnell, Christopher J; Kupka, Michelle J; Larson, Martin G; Kissinger, Kraig V; Edelman, Robert R; Levy, Daniel; Manning, Warren J

2002-03-20

We sought to derive gender-specific cardiovascular magnetic resonance (CMR) reference values for normative left ventricular (LV) anatomy and function in a healthy adult population of clinically relevant age. Cardiovascular magnetic resonance imaging is increasingly applied in the clinical setting, but age-relevant, gender-specific normative values are currently unavailable. A representative sample of 318 Framingham Heart Study (FHS) Offspring participants free of clinically overt cardiovascular disease underwent CMR examination to determine LV end-diastolic and end-systolic volume (EDV and ESV, respectively), mass, ejection fraction (EF) and linear dimensions (wall thickness, cavity length). Subjects with a clinical history of hypertension or those with a systolic blood pressure > or =140 mm Hg or diastolic pressure > or =90 mm Hg at any FHS cycle examination were excluded, leaving 142 subjects (63 men, 79 women; age 57 +/- 9 years). All volumetric (EDV, ESV, mass) and unidimensional measures were significantly greater (p < 0.001) in men than in women and remained greater (p < 0.02) after adjustment for subject height. Volumetric measures were greater (p < 0.001) in men than in women after adjustment for body surface area (BSA), but there were increased linear dimensions in women after adjustment for BSA. In particular, end-diastolic dimension indexed to BSA was greater in women (p < 0.001) than in men. There were no gender differences in global LVEF (men = 0.69; women = 0.70). Cardiovascular magnetic resonance measures of LV volumes, mass and linear dimensions differ significantly according to gender and body size. This study provides gender-specific normal CMR reference values, uniquely derived from a population-based sample of persons free of cardiovascular disease and clinical hypertension. These data may serve as a reference to identify LV pathology in the adult population.

iPhone 4s Photoplethysmography: Which Light Color Yields the Most Accurate Heart Rate and Normalized Pulse Volume Using the iPhysioMeter Application in the Presence of Motion Artifact?

PubMed Central

Matsumura, Kenta; Rolfe, Peter; Lee, Jihyoung; Yamakoshi, Takehiro

2014-01-01

Recent progress in information and communication technologies has made it possible to measure heart rate (HR) and normalized pulse volume (NPV), which are important physiological indices, using only a smartphone. This has been achieved with reflection mode photoplethysmography (PPG), by using a smartphone’s embedded flash as a light source and the camera as a light sensor. Despite its widespread use, the method of PPG is susceptible to motion artifacts as physical displacements influence photon propagation phenomena and, thereby, the effective optical path length. Further, it is known that the wavelength of light used for PPG influences the photon penetration depth and we therefore hypothesized that influences of motion artifact could be wavelength-dependant. To test this hypothesis, we made measurements in 12 healthy volunteers of HR and NPV derived from reflection mode plethysmograms recorded simultaneously at three different spectral regions (red, green and blue) at the same physical location with a smartphone. We then assessed the accuracy of the HR and NPV measurements under the influence of motion artifacts. The analyses revealed that the accuracy of HR was acceptably high with all three wavelengths (all rs > 0.996, fixed biases: −0.12 to 0.10 beats per minute, proportional biases: r = −0.29 to 0.03), but that of NPV was the best with green light (r = 0.791, fixed biases: −0.01 arbitrary units, proportional bias: r = 0.11). Moreover, the signal-to-noise ratio obtained with green and blue light PPG was higher than that of red light PPG. These findings suggest that green is the most suitable color for measuring HR and NPV from the reflection mode photoplethysmogram under motion artifact conditions. We conclude that the use of green light PPG could be of particular benefit in ambulatory monitoring where motion artifacts are a significant issue. PMID:24618594

A Public University's Defense of Free Expression: The Issues and Events in the Staging of "The Normal Heart."

ERIC Educational Resources Information Center

Smith, Ralph R.; Moore, Dale

In 1989, some Springfield, Missouri residents demanded cancellation of the Southwest Missouri State University (SMSU) theater department's production of Larry Kramer's play, "The Normal Heart," which they alleged to be obscene. Opponents purchased newspaper advertisements which charged that the publicly funded production promoted a…

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.

Influence of gestational age and time of day in baseline and heart rate variation of fetuses.

PubMed

Li, Guangfei; Zhang, Song; Yang, Lin; Li, Shufang; Wang, Yan; Hao, Dongmei; Yang, Yimin; Li, Xuwen; Zhang, Lei; Xu, Mingzhou

2016-04-29

Fetal electrocardiography (FECG) places electrodes on the maternal abdomen to convert the fetal electrocardiosignals into fetal heart rate (FHR), improving the accuracy and comfort of pregnant woman. At the same time, FECG simplifies the procedure of long term monitoring in the perinatal period. Investigating the influence of gestational age and time of day on FHR features to distinguish between non-stress test (NST) normal fetuses and NST suspicious fetuses. A novel method of FHR baseline estimation was presented; then baseline value and fetal heart rate variation (FHRV) were analyzed in the time domain using FHR signals recorded from 52 fetuses. Baseline values in 1:00, 2:00, 4:00, 5:00 and heart rate variation (HRV) distribution showed a significant difference (p< 0.05) between NST normal fetuses and NST suspicious fetuses. The results suggest that NST normal and suspicious fetuses had same outcome and different FHR features. Accurately distinguishing normal fetuses and suspicious fetuses is important for lowering the false positive rate and reducing unnecessary clinical intervention.

Dose-mass inverse optimization for minimally moving thoracic lesions

NASA Astrophysics Data System (ADS)

Mihaylov, I. B.; Moros, E. G.

2015-05-01

In the past decade, several different radiotherapy treatment plan evaluation and optimization schemes have been proposed as viable approaches, aiming for dose escalation or an increase of healthy tissue sparing. In particular, it has been argued that dose-mass plan evaluation and treatment plan optimization might be viable alternatives to the standard of care, which is realized through dose-volume evaluation and optimization. The purpose of this investigation is to apply dose-mass optimization to a cohort of lung cancer patients and compare the achievable healthy tissue sparing to that one achievable through dose-volume optimization. Fourteen non-small cell lung cancer (NSCLC) patient plans were studied retrospectively. The range of tumor motion was less than 0.5 cm and motion management in the treatment planning process was not considered. For each case, dose-volume (DV)-based and dose-mass (DM)-based optimization was performed. Nine-field step-and-shoot IMRT was used, with all of the optimization parameters kept the same between DV and DM optimizations. Commonly used dosimetric indices (DIs) such as dose to 1% the spinal cord volume, dose to 50% of the esophageal volume, and doses to 20 and 30% of healthy lung volumes were used for cross-comparison. Similarly, mass-based indices (MIs), such as doses to 20 and 30% of healthy lung masses, 1% of spinal cord mass, and 33% of heart mass, were also tallied. Statistical equivalence tests were performed to quantify the findings for the entire patient cohort. Both DV and DM plans for each case were normalized such that 95% of the planning target volume received the prescribed dose. DM optimization resulted in more organs at risk (OAR) sparing than DV optimization. The average sparing of cord, heart, and esophagus was 23, 4, and 6%, respectively. For the majority of the DIs, DM optimization resulted in lower lung doses. On average, the doses to 20 and 30% of healthy lung were lower by approximately 3 and 4%, whereas lung volumes receiving 2000 and 3000 cGy were lower by 3 and 2%, respectively. The behavior of MIs was very similar. The statistical analyses of the results again indicated better healthy anatomical structure sparing with DM optimization. The presented findings indicate that dose-mass-based optimization results in statistically significant OAR sparing as compared to dose-volume-based optimization for NSCLC. However, the sparing is case-dependent and it is not observed for all tallied dosimetric endpoints.

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

Commonly Asked Questions about Children and Heart Disease

MedlinePlus

... heart is a pump with a built-in electrical system. Normally, electricity starts in the upper chamber and spreads to ... function. Heart block occurs when the spread of electricity from the upper chambers (atria) to the lower ...

Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

1986-01-01

Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

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.

Analysis of Molecular Movement Reveals Latticelike Obstructions to Diffusion in Heart Muscle Cells

PubMed Central

Illaste, Ardo; Laasmaa, Martin; Peterson, Pearu; Vendelin, Marko

2012-01-01

Intracellular diffusion in muscle cells is known to be restricted. Although characteristics and localization of these restrictions is yet to be elucidated, it has been established that ischemia-reperfusion injury reduces the overall diffusion restriction. Here we apply an extended version of raster image correlation spectroscopy to determine directional anisotropy and coefficients of diffusion in rat cardiomyocytes. Our experimental results indicate that diffusion of a smaller molecule (1127 MW fluorescently labeled ATTO633-ATP) is restricted more than that of a larger one (10,000 MW Alexa647-dextran), when comparing diffusion in cardiomyocytes to that in solution. We attempt to provide a resolution to this counterintuitive result by applying a quantitative stochastic model of diffusion. Modeling results suggest the presence of periodic intracellular barriers situated ∼1 μm apart having very low permeabilities and a small effect of molecular crowding in volumes between the barriers. Such intracellular structuring could restrict diffusion of molecules of energy metabolism, reactive oxygen species, and apoptotic signals, enacting a significant role in normally functioning cardiomyocytes as well as in pathological conditions of the heart. PMID:22385844

Prenatal diagnosis of brain abnormalities in Wolf-Hirschhorn (4p-) syndrome.

PubMed

De Keersmaecker, B; Albert, M; Hillion, Y; Ville, Y

2002-05-01

Although there have been occasional reports of prenatal diagnosis of this syndrome, most cases are diagnosed postnatally. The objective was to evaluate the presence of brain abnormalities in the prenatal diagnosis of Wolf-Hirschhorn syndrome. Prenatal ultrasound and MRI examination of the fetal brain were performed in a case of Wolf-Hirschhorn syndrome. A comprehensive review of Wolf-Hirschhorn syndrome reported between 1960 and 2000 in the literature was carried out. The late diagnosis of a growth-retarded fetus with normal amniotic fluid volume, normal Doppler and negative infection screen calls for a detailed examination of the fetal brain and heart. Multifocal white matter lesions and periventricular cystic changes, which are often attributed to perinatal distress, are possible prenatal features causing suspicion of 4p- syndrome in an IUGR fetus. Subtle abnormalities on ultrasound may suggest a chromosomal problem. Standard cytogenetics cannot always demonstrate a microdeletion. High-resolution banding and molecular analysis can help to confirm the diagnosis. Copyright 2002 John Wiley & Sons, Ltd.

Automated liver segmentation using a normalized probabilistic atlas

NASA Astrophysics Data System (ADS)

Linguraru, Marius George; Li, Zhixi; Shah, Furhawn; Chin, See; Summers, Ronald M.

2009-02-01

Probabilistic atlases of anatomical organs, especially the brain and the heart, have become popular in medical image analysis. We propose the construction of probabilistic atlases which retain structural variability by using a size-preserving modified affine registration. The organ positions are modeled in the physical space by normalizing the physical organ locations to an anatomical landmark. In this paper, a liver probabilistic atlas is constructed and exploited to automatically segment liver volumes from abdominal CT data. The atlas is aligned with the patient data through a succession of affine and non-linear registrations. The overlap and correlation with manual segmentations are 0.91 (0.93 DICE coefficient) and 0.99 respectively. Little work has taken place on the integration of volumetric measures of liver abnormality to clinical evaluations, which rely on linear estimates of liver height. Our application measures the liver height at the mid-hepatic line (0.94 correlation with manual measurements) and indicates that its combination with volumetric estimates could assist the development of a noninvasive tool to assess hepatomegaly.

Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

NASA Astrophysics Data System (ADS)

Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

2017-09-01

Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

Dosimetric evaluation of integrated IMRT treatment of the chest wall and supraclavicular region for breast cancer after modified radical mastectomy

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

Yang, Bo; Wei, Xian-ding; Zhao, Yu-tian

2014-07-01

To investigate the dosimetric characteristics of irradiation of the chest wall and supraclavicular region as an integrated volume with intensity-modulated radiation therapy (IMRT) after modified radical mastectomy. This study included 246 patients who received modified radical mastectomy. The patients were scanned with computed tomography, and the chest wall (with or without the internal mammary lymph nodes) and supraclavicular region were delineated. For 143 patients, the chest wall and supraclavicular region were combined as an integrated planning volume and treated with IMRT. For 103 patients, conventional treatments were employed with 2 tangential fields for the chest wall, abutting a mixed fieldmore » of 6-MV x-rays (16 Gy) and 9-MeV electrons (34 Gy) for the upper supraclavicular region. The common prescription dose was 50 Gy/25 Fx/5 W to 90% of the target volume. The dosimetric characteristics of the chest wall, the supraclavicular region, and normal organs were compared. For the chest wall target, compared with conventional treatments, the integrated IMRT plans lowered the maximum dose, increased the minimum dose, and resulted in better conformity and uniformity of the target volume. There was an increase in minimum, average, and 95% prescription dose for the integrated IMRT plans in the supraclavicular region, and conformity and uniformity were improved. The V{sub 30} of the ipsilateral lung and V{sub 10}, V{sub 30}, and mean dose of the heart on the integrated IMRT plans were lower than those of the conventional plans. The V{sub 5} and V{sub 10} of the ipsilateral lung and V{sub 5} of the heart were higher on the integrated IMRT plans (p < 0.05) than on conventional plans. Without an increase in the radiation dose to organs at risk, the integrated IMRT treatment plans improved the dose distribution of the supraclavicular region and showed better dose conformity and uniformity of the integrated target volume of the chest wall and supraclavicular region.« less

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.

Is applying the same exercise-based inpatient program to normal and reduced left ventricular function patients the best strategy after coronary surgery? A focus on autonomic cardiac response.

PubMed

Mendes, Renata Gonçalves; Simões, Rodrigo Polaquini; Costa, Fernando de Souza Melo; Pantoni, Camila Bianca Falasco; Di Thommazo-Luporini, Luciana; Luzzi, Sérgio; Amaral-Neto, Othon; Arena, Ross; Catai, Aparecida Maria; Borghi-Silva, Audrey

2014-01-01

To assess whether the same exercise-based inpatient program applied to patients with normal and reduced left ventricular function (LVF) evokes a similar cardiac autonomic response after coronary artery bypass graft (CABG). Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23; left ventricular ejection fraction (LVEF) ≥ 55%] and reduced LVF (LVFR: n = 21; LVEF 35-54%), were included. All initiated the exercise protocol on post-operative day 1 (PO1), following a whole progressive program until discharge. Cardiac autonomic response was assessed by the indices of heart rate variability (HRV) at rest and during exercise (extremity range of motion and ambulation). During ambulation, lower values of HRV indices were found in the LVFR group compared with the LVFN group [standard deviation of all RR (STDRR; 6.1 ± 2.7 versus 8.9 ± 4.7 ms), baseline width of the RR histogram (TINN; 30.6 ± 14.8 versus 45.8 ± 24.9 ms), SD2 (14.8 ± 8.0 versus 21.3 ± 9.0 ms), Shannon entropy (3.6 ± 0.5 versus 3.9 ± 0.4) and correlation dimension (0.08 ± 0.2 versus 0.2 ± 0.2)]. Also, when comparing the ambulation to rest change, lower values were observed in the LVFR group for linear (STDRR, TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices (p < 0.05). On PO1, we observed only intra-group differences between rest and exercise (extremity range of motion), for mean intervals between heart beats and heart rate. For patients with LVFN, the same inpatient exercise protocol triggered a more attenuated autonomic response compared with patients with LVFR. These findings have implications as to how exercise should be prescribed according to LVF in the early stages following recovery from CABG. Implications for Rehabilitation Exercise-based inpatient program, performed by post-CABG patients who have normal left ventricular function, triggered a more attenuated cardiac autonomic response compared with patients with reduced left ventricular function. Volume of the inpatient exercises should be prescribed according to the left ventricular function in the early stages following recovery from CABG.

Dosimetric comparison of photon and proton treatment techniques for chondrosarcoma of thoracic spine

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

Yadav, Poonam, E-mail: yadav@humonc.wisc.edu; Department of Medical Physics, University of Wisconsin, Madison, WI; University of Wisconsin Riverview Cancer Center, Wisconsin Rapids, WI

2013-10-01

Chondrosarcomas are relatively radiotherapy resistant, and also delivering high radiation doses is not feasible owing to anatomic constraints. In this study, the feasibility of helical tomotherapy for treatment of chondrosarcoma of thoracic spine is explored and compared with other available photon and proton radiotherapy techniques in the clinical setting. A patient was treated for high-grade chondrosarcoma of the thoracic spine using tomotherapy. Retrospectively, the tomotherapy plan was compared with intensity-modulated radiation therapy, dynamic arc photon therapy, and proton therapy. Two primary comparisons were made: (1) comparison of normal tissue sparing with comparable target volume coverage (plan-1), and (2) comparison ofmore » target volume coverage with a constrained maximum dose to the cord center (plan-2). With constrained target volume coverage, proton plans were found to yield lower mean doses for all organs at risk (spinal cord, esophagus, heart, and both lungs). Tomotherapy planning resulted in the lowest mean dose to all organs at risk amongst photon-based methods. For cord dose constrained plans, the static-field intensity-modulated radiation therapy and dynamic arc plans resulted target underdosing in 20% and 12% of planning target volume2 volumes, respectively, whereas both proton and tomotherapy plans provided clinically acceptable target volume coverage with no portion of planning target volume2 receiving less than 90% of the prescribed dose. Tomotherapy plans are comparable to proton plans and produce superior results compared with other photon modalities. This feasibility study suggests that tomotherapy is an attractive alternative to proton radiotherapy for delivering high doses to lesions in the thoracic spine.« less

Evaluation of clinical and paraclinical effects of intraosseous vs intravenous administration of propofol on general anesthesia in rabbits

PubMed Central

Mazaheri-Khameneh, Ramin; Sarrafzadeh-Rezaei, Farshid; Asri-Rezaei, Siamak; Dalir-Naghadeh, Bahram

2012-01-01

This prospective study aimed to compare the intraosseous (IO) and intravenous (IV) effects of propofol on selected blood parameters and physiological variables during general anesthesia in rabbits. Thirty New Zealand White rabbits were studied. Six rabbits received IV propofol (group 1) and another 6 rabbits, were injected propofol intraosseously (Group 2) for 30 minutes (experimental groups). Rabbits of the third and fourth groups received IV and IO normal saline at the same volume given to the experimental groups, respectively. In the fifth group IO cannulation was performed but neither propofol nor normal saline were administered. Blood profiles were assayed before induction and after recovery of anesthesia. Heart and respiratory rates, rectal temperature, saturation of peripheral oxygen and mean arterial blood pressure were recorded. Heart rate increased significantly 1 to 5 minutes after induction of anesthesia in experimental groups (P < 0.05). Although mean arterial blood pressure decreased significantly from baseline, values remained above 60 mm Hg (P < 0.05). Respiratory rate decreased significantly in experimental groups, but remained higher in group 2 (P < 0.05). The lymphocyte count decreased significantly in group 1 (P < 0.05). The concentration of alkaline phosphatase in all rabbits, aspartate aminotransferase and gamma-glutamyl transferase in the first group and gamma-glutamyl transferase in the third group increased significantly (P < 0.05). Total bilirubin decreased significantly in group 2 (P < 0.05). All measured values remained within normal limits. Based on the least significant physiological, hematological and biochemical effects, the IO injection of propofol appears to be safe and suitable method of anesthesia in rabbits with limited vascular access. PMID:25653755

Evaluation of clinical and paraclinical effects of intraosseous vs intravenous administration of propofol on general anesthesia in rabbits.

PubMed

Mazaheri-Khameneh, Ramin; Sarrafzadeh-Rezaei, Farshid; Asri-Rezaei, Siamak; Dalir-Naghadeh, Bahram

2012-01-01

This prospective study aimed to compare the intraosseous (IO) and intravenous (IV) effects of propofol on selected blood parameters and physiological variables during general anesthesia in rabbits. Thirty New Zealand White rabbits were studied. Six rabbits received IV propofol (group 1) and another 6 rabbits, were injected propofol intraosseously (Group 2) for 30 minutes (experimental groups). Rabbits of the third and fourth groups received IV and IO normal saline at the same volume given to the experimental groups, respectively. In the fifth group IO cannulation was performed but neither propofol nor normal saline were administered. Blood profiles were assayed before induction and after recovery of anesthesia. Heart and respiratory rates, rectal temperature, saturation of peripheral oxygen and mean arterial blood pressure were recorded. Heart rate increased significantly 1 to 5 minutes after induction of anesthesia in experimental groups (P < 0.05). Although mean arterial blood pressure decreased significantly from baseline, values remained above 60 mm Hg (P < 0.05). Respiratory rate decreased significantly in experimental groups, but remained higher in group 2 (P < 0.05). The lymphocyte count decreased significantly in group 1 (P < 0.05). The concentration of alkaline phosphatase in all rabbits, aspartate aminotransferase and gamma-glutamyl transferase in the first group and gamma-glutamyl transferase in the third group increased significantly (P < 0.05). Total bilirubin decreased significantly in group 2 (P < 0.05). All measured values remained within normal limits. Based on the least significant physiological, hematological and biochemical effects, the IO injection of propofol appears to be safe and suitable method of anesthesia in rabbits with limited vascular access.

New Role for Interleukin-13 Receptor α1 in Myocardial Homeostasis and Heart Failure.

PubMed

Amit, Uri; Kain, David; Wagner, Allon; Sahu, Avinash; Nevo-Caspi, Yael; Gonen, Nir; Molotski, Natali; Konfino, Tal; Landa, Natalie; Naftali-Shani, Nili; Blum, Galia; Merquiol, Emmanuelle; Karo-Atar, Danielle; Kanfi, Yariv; Paret, Gidi; Munitz, Ariel; Cohen, Haim Y; Ruppin, Eytan; Hannenhalli, Sridhar; Leor, Jonathan

2017-05-20

The immune system plays a pivotal role in myocardial homeostasis and response to injury. Interleukins-4 and -13 are anti-inflammatory type-2 cytokines, signaling via the common interleukin-13 receptor α1 chain and the type-2 interleukin-4 receptor. The role of interleukin-13 receptor α1 in the heart is unknown. We analyzed myocardial samples from human donors (n=136) and patients with end-stage heart failure (n=177). We found that the interleukin-13 receptor α1 is present in the myocardium and, together with the complementary type-2 interleukin-4 receptor chain Il4ra , is significantly downregulated in the hearts of patients with heart failure. Next, we showed that Il13ra1 -deficient mice develop severe myocardial dysfunction and dyssynchrony compared to wild-type mice (left ventricular ejection fraction 29.7±9.9 versus 45.0±8.0; P =0.004, left ventricular end-diastolic diameter 4.2±0.2 versus 3.92±0.3; P =0.03). A bioinformatic analysis of mouse hearts indicated that interleukin-13 receptor α1 regulates critical pathways in the heart other than the immune system, such as extracellular matrix (normalized enrichment score=1.90; false discovery rate q=0.005) and glucose metabolism (normalized enrichment score=-2.36; false discovery rate q=0). Deficiency of Il13ra1 was associated with reduced collagen deposition under normal and pressure-overload conditions. The results of our studies in humans and mice indicate, for the first time, a role of interleukin-13 receptor α1 in myocardial homeostasis and heart failure and suggests a new therapeutic target to treat heart disease. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Optimal Body Temperature in Transitional ELBW Infants Using Heart Rate and Temperature as Indicators

PubMed Central

Knobel, Robin B.; Holditch-Davis, Diane; Schwartz, Todd A.

2013-01-01

Extremely low birth weight (ELBW) infants are vulnerable to cold stress after birth. Therefore, caregivers need to control body temperature optimally to minimize energy expenditure. Objective We explored body temperature in relationship to heart rate in ELBW infants during their first 12 hours to help identify the ideal set point for incubator control of body temperature. Design Within subject, multiple-case design. Setting A tertiary NICU in North Carolina. Participants 10 infants, born less than 29 weeks gestation and weighing 400-1000 grams. Methods Heart rate and abdominal body temperature were measured at 1-minute intervals for 12 hours. Heart rates were considered normal if they were between the 25th and 75th percentile for each infant. Results Abdominal temperatures were low throughout the 12-hour study period (mean 35.17° C-36.68° C). Seven of ten infants had significant correlations between abdominal temperature and heart rate. Heart rates above the 75th percentile were associated with low and high abdominal temperatures; heart rates less than the 25th percentile were associated with very low abdominal temperatures. The extent to which abdominal temperature was abnormally low was related the extent to which the heart rate trended away from normal in six of the ten infants. Optimal temperature control point that maximized normal heart rate observations for each infant was between 36.8° C and 37° C. Conclusions Hypothermia was associated with abnormal heart rates in transitional ELBW infants. We suggest nurses set incubator servo between 36.8° C and 36.9° C to optimally control body temperature for ELBW infants. PMID:20409098

NEUROTICISM PROFILE IN CORONARY HEART DISEASE

PubMed Central

Bhargava, S. C.; Sharma, S. N.; Agarwal, B. V.

1980-01-01

SUMMARY Thirty seven cases of coronary heart disease and 30 normal healthy controls were administered Hindi version of MHQ. The coronary heart disease patients scored significantly higher on total neuroticism, free-floating anxiety and somatic anxiety subscales of MHQ. PMID:22058440

White Matter Volume Predicts Language Development in Congenital Heart Disease.

PubMed

Rollins, Caitlin K; Asaro, Lisa A; Akhondi-Asl, Alireza; Kussman, Barry D; Rivkin, Michael J; Bellinger, David C; Warfield, Simon K; Wypij, David; Newburger, Jane W; Soul, Janet S

2017-02-01

To determine whether brain volume is reduced at 1 year of age and whether these volumes are associated with neurodevelopment in biventricular congenital heart disease (CHD) repaired in infancy. Infants with biventricular CHD (n = 48) underwent brain magnetic resonance imaging (MRI) and neurodevelopmental testing with the Bayley Scales of Infant Development-II and the MacArthur-Bates Communicative Development Inventories at 1 year of age. A multitemplate based probabilistic segmentation algorithm was applied to volumetric MRI data. We compared volumes with those of 13 healthy control infants of comparable ages. In the group with CHD, we measured Spearman correlations between neurodevelopmental outcomes and the residuals from linear regression of the volumes on corrected chronological age at MRI and sex. Compared with controls, infants with CHD had reductions of 54 mL in total brain (P = .009), 40 mL in cerebral white matter (P <.001), and 1.2 mL in brainstem (P = .003) volumes. Within the group with CHD, brain volumes were not correlated with Bayley Scales of Infant Development-II scores but did correlate positively with MacArthur-Bates Communicative Development Inventory language development. Infants with biventricular CHD show total brain volume reductions at 1 year of age, driven by differences in cerebral white matter. White matter volume correlates with language development, but not broader developmental indices. These findings suggest that abnormalities in white matter development detected months after corrective heart surgery may contribute to language impairment. ClinicalTrials.gov: NCT00006183. Copyright © 2016 Elsevier Inc. All rights reserved.

The relationship between heart rate recovery and brain natruretic Peptide in patients with chest discomfort: a study for relationship between heart rate recovery and pre-exercise, post-exercise levels of brain natruretic Peptide in patients with normal systolic function and chest discomfort.

PubMed

Lee, Jae Eun; Kim, Bum Soo; Park, Wan; Huh, Jung Kwon; Kim, Byung Jin; Sung, Ki Chul; Kang, Jin Ho; Lee, Man Ho; Park, Jung Ro

2010-04-01

The correlation between brain natruretic peptide (BNP) level and cardiac autonomic function has been studied in type 2 diabetic patients. However, there is limited data from patients with normal systolic function. We evaluated the association between heart rate recovery (HRR) representing autonomic dysfunction and three plasma BNP levels: pre-exercise, post-exercise, and change during exercise in patients with normal systolic function. Subjects included 105 patients with chest pain and normal systolic function. HRR was defined as the difference between the peak heart rate and the rate measured two minutes after completion of a treadmill exercise test. We measured plasma BNP levels before exercise, 5 minutes after completion of exercise, and during exercise (absolute value of difference between pre- and post-exercise BNP levels). Patients with abnormal HRR values (

Long-Term Coarse Particulate Matter Exposure and Heart Rate Variability in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Adhikari, Richa; D’Souza, Jennifer; Solimon, Elsayed Z.; Burke, Gregory L.; Daviglus, Martha; Jacobs, David R.; Park, Sung Kyun; Sheppard, Lianne; Thorne, Peter S.; Kaufman, Joel D.; Larson, Timothy V.; Adar, Sara D.

2017-01-01

Background Reduced heart rate variability, a marker of impaired cardiac autonomic function, has been linked to short-term exposure to airborne particles. This research adds to the literature by examining associations with long-term exposures to coarse particles (PM10-2.5). Methods Using electrocardiogram recordings from 2,780 participants (45-84 years) from three Multi-Ethnic Study of Atherosclerosis sites, we assessed the standard deviation of normal-to-normal intervals (SDNN) and root-mean square differences of successive normal-to-normal intervals (rMSSD) at a baseline (2000-2002) and follow-up (2010-2012) examination (mean visits/person=1.5). Annual average concentrations of PM10-2.5 mass, copper, zinc, phosphorus, silicon, and endotoxin were estimated using site-specific spatial prediction models. We assessed associations for baseline heart rate variability and rate of change in heart rate variability over time using multivariable mixed models adjusted for time, sociodemographic, lifestyle, health, and neighborhood confounders, including co-pollutants. Results In our primary models adjusted for demographic and lifestyle factors and site, PM10-2.5 mass was associated with 1.0% (95% CI: -4.1, 2.1%) lower SDNN levels per interquartile range of 2 μg/m3. Stronger associations, however, were observed prior to site adjustment and with increasing residential stablity. Similar patterns were found for rMSSD. We found little evidence for associations with other chemical species and with with the rate of change in heart rate variability, though endotoxin was associated with increasing heart rate variability over time. Conclusion We found only weak evidence that long-term PM10-2.5 exposures are associated with lowered heart rate variability. Stronger associations among residentially stable individuals suggest that confirmatory studies are needed. PMID:27035690

Usefulness of the novel risk estimation software, Heart Risk View, for the prediction of cardiac events in patients with normal myocardial perfusion SPECT.

PubMed

Sakatani, Tomohiko; Shimoo, Satoshi; Takamatsu, Kazuaki; Kyodo, Atsushi; Tsuji, Yumika; Mera, Kayoko; Koide, Masahiro; Isodono, Koji; Tsubakimoto, Yoshinori; Matsuo, Akiko; Inoue, Keiji; Fujita, Hiroshi

2016-12-01

Myocardial perfusion single-photon emission-computed tomography (SPECT) can predict cardiac events in patients with coronary artery disease with high accuracy; however, pseudo-negative cases sometimes occur. Heart Risk View, which is based on the prospective cohort study (J-ACCESS), is a software for evaluating cardiac event probability. We examined whether Heart Risk View was useful to evaluate the cardiac risk in patients with normal myocardial perfusion SPECT (MPS). We studied 3461 consecutive patients who underwent MPS to detect myocardial ischemia and those who had normal MPS were enrolled in this study (n = 698). We calculated cardiac event probability by Heart Risk View and followed-up for 3.8 ± 2.4 years. The cardiac events were defined as cardiac death, non-fatal myocardial infarction, and heart failure requiring hospitalization. During the follow-up period, 21 patients (3.0 %) had cardiac events. The event probability calculated by Heart Risk View was higher in the event group (5.5 ± 2.6 vs. 2.9 ± 2.6 %, p < 0.001). According to the receiver-operating characteristics curve, the cut-off point of the event probability for predicting cardiac events was 3.4 % (sensitivity 0.76, specificity 0.72, and AUC 0.85). Kaplan-Meier curves revealed that a higher event rate was observed in the high-event probability group by the log-rank test (p < 0.001). Although myocardial perfusion SPECT is useful for the prediction of cardiac events, risk estimation by Heart Risk View adds more prognostic information, especially in patients with normal MPS.

Nondestructive and rapid detection of potato black heart based on machine vision technology

NASA Astrophysics Data System (ADS)

Tian, Fang; Peng, Yankun; Wei, Wensong

2016-05-01

Potatoes are one of the major food crops in the world. Potato black heart is a kind of defect that the surface is intact while the tissues in skin become black. This kind of potato has lost the edibleness, but it's difficult to be detected with conventional methods. A nondestructive detection system based on the machine vision technology was proposed in this study to distinguish the normal and black heart of potatoes according to the different transmittance of them. The detection system was equipped with a monochrome CCD camera, LED light sources for transmitted illumination and a computer. Firstly, the transmission images of normal and black heart potatoes were taken by the detection system. Then the images were processed by algorithm written with VC++. As the transmitted light intensity was influenced by the radial dimension of the potato samples, the relationship between the grayscale value and the potato radial dimension was acquired by analyzing the grayscale value changing rule of the transmission image. Then proper judging condition was confirmed to distinguish the normal and black heart of potatoes after image preprocessing. The results showed that the nondestructive system built coupled with the processing methods was accessible for the detection of potato black heart at a considerable accuracy rate. The transmission detection technique based on machine vision is nondestructive and feasible to realize the detection of potato black heart.

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

Automated tissue classification of intracardiac optical coherence tomography images (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gan, Yu; Tsay, David; Amir, Syed B.; Marboe, Charles C.; Hendon, Christine P.

2016-03-01

Remodeling of the myocardium is associated with increased risk of arrhythmia and heart failure. Our objective is to automatically identify regions of fibrotic myocardium, dense collagen, and adipose tissue, which can serve as a way to guide radiofrequency ablation therapy or endomyocardial biopsies. Using computer vision and machine learning, we present an automated algorithm to classify tissue compositions from cardiac optical coherence tomography (OCT) images. Three dimensional OCT volumes were obtained from 15 human hearts ex vivo within 48 hours of donor death (source, NDRI). We first segmented B-scans using a graph searching method. We estimated the boundary of each region by minimizing a cost function, which consisted of intensity, gradient, and contour smoothness. Then, features, including texture analysis, optical properties, and statistics of high moments, were extracted. We used a statistical model, relevance vector machine, and trained this model with abovementioned features to classify tissue compositions. To validate our method, we applied our algorithm to 77 volumes. The datasets for validation were manually segmented and classified by two investigators who were blind to our algorithm results and identified the tissues based on trichrome histology and pathology. The difference between automated and manual segmentation was 51.78 +/- 50.96 μm. Experiments showed that the attenuation coefficients of dense collagen were significantly different from other tissue types (P < 0.05, ANOVA). Importantly, myocardial fibrosis tissues were different from normal myocardium in entropy and kurtosis. The tissue types were classified with an accuracy of 84%. The results show good agreements with histology.

Severe tricuspid regurgitation and isolated right heart failure due to thyrotoxicosis

PubMed Central

Bonou, Maria; Lampropoulos, Konstantinos M.; Andriopoulou, Maria; Kotsas, Dimitrios; Lakoumentas, John; Barbetseas, John

2012-01-01

We describe the case of a patient presented with isolated right heart failure with atrial fibrillation and severe tricuspid regurgitation due to hyperthyroidism. Treatment of the thyroid disease resulted in the disappearance of signs of right heart failure and resolution of the valve incompetence and normalization of the heart rhythm. Although thyrotoxicosis may be associated with congestive heart failure, isolated right heart failure with marked tricuspid regurgitation is rarely seen. PMID:23253416

Treatment of shock.

PubMed

Hardaway, R M

1979-03-01

In order to effectively treat shock the physician must understand the physiology of shock. Shock patients may have a low, normal, or high arterial blood pressure, and the blood volume may be below normal, normal, or above normal. Shock is not necessarily accompanied by low arterial pH or low peripheral resistance. Most cases of acute traumatic and hemorrhagic shock show a high arterial pH, partly due to the blowing off of CO2, despite an elevated blood lactic acid level. Most patients also show a very high resistance. A factor that all shock patients have in common is a deficient capillary perfusion, or an insufficient amount of blood flowing through the capillaries. The cornerstone of the treatment of hypovolemic shock is the administration of adequate amounts of the right kinds of intravenous fluids. Focus is on classification of shock (reversible shock, irreversible or fatal shock, hypovolemia), the heart in shock, respiration, drugs (steroids, vasoactive drugs), and disseminated intravascular coagulation. If edema is a problem, diuretics may be helpful. Antibiotics for infection are very important in sepsis and septic shock. Supportive drugs are also important. Steroids and vasoactive drugs have a secondary place in the treatment of shock, and they should be used when these treatments have failed to produce an adequate blood pressure and urinary output.

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.

Recent findings in cardiovascular physiology with space travel.

PubMed

Hughson, Richard L

2009-10-01

The cardiovascular system undergoes major changes in stress with space flight primarily related to the elimination of the head-to-foot gravitational force. A major observation has been that the central venous pressure is not elevated early in space flight yet stroke volume is increased at least early in flight. Recent observations demonstrate that heart rate remains lower during the normal daily activities of space flight compared to Earth-based conditions. Structural and functional adaptations occur in the vascular system that could result in impaired response with demands of physical exertion and return to Earth. Cardiac muscle mass is reduced after flight and contractile function may be altered. Regular and specific countermeasures are essential to maintain cardiovascular health during long-duration space flight.

Automated processing of first-pass radioisotope ventriculography data to determine essential central circulation parameters

NASA Astrophysics Data System (ADS)

Krotov, Aleksei; Pankin, Victor

2017-09-01

The assessment of central circulation (including heart function) parameters is vital in the preventive diagnostics of inherent and acquired heart failures and during polychemotherapy. The protocols currently applied in Russia do not fully utilize the first-pass assessment (FPRNA) and that results in poor data formalization, while the FPRNA is the one of the fastest, affordable and compact methods among other radioisotope diagnostics protocols. A non-imaging algorithm basing on existing protocols has been designed to use the readings of an additional detector above vena subclavia to determine the total blood volume (TBV), not requiring blood sampling in contrast to current protocols. An automated processing of precordial detector readings is presented, in order to determine the heart strike volume (SV). Two techniques to estimate the ejection fraction (EF) of the heart are discussed.

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.

Low Transvalvular Flow Rate Predicts Mortality in Patients With Low-Gradient Aortic Stenosis Following Aortic Valve Intervention.

PubMed

Vamvakidou, Anastasia; Jin, Wenying; Danylenko, Oleksandr; Chahal, Navtej; Khattar, Rajdeep; Senior, Roxy

2018-03-09

This study aimed to assess the value of low transvalvular flow rate (FR) for the prediction of mortality compared with low stroke volume index (SVi) in patients with low-gradient (mean gradient: <40 mm Hg), low aortic valve area (<1 cm 2 ) aortic stenosis (AS) following aortic valve intervention. Transaortic FR defined as stroke volume/left ventricular ejection time is also a marker of flow; however, no data exist comparing the relative prognostic value of these 2 transvalvular flow markers in patients with low-gradient AS who had undergone valve intervention. We retrospectively followed prospectively assessed consecutive patients with low-gradient, low aortic valve area AS who underwent aortic valve intervention between 2010 and 2014 for all-cause mortality. Of the 218 patients with mean age 75 ± 12 years, 102 (46.8%) had low stroke volume index (SVi) (<35 ml/m 2 ), 95 (43.6%) had low FR (<200 ml/s), and 58 (26.6%) had low left ventricular ejection fraction <50%. The concordance between FR and SVi was 78.8% (p < 0.005). Over a median follow-up of 46.8 ± 21 months, 52 (23.9%) deaths occurred. Patients with low FR had significantly worse outcome compared with those with normal FR (p < 0.005). In patients with low SVi, a low FR conferred a worse outcome than a normal FR (p = 0.005), but FR status did not discriminate outcome in patients with normal SVi. By contrast, SVi did not discriminate survival either in patients with normal or low FR. Low FR was an independent predictor of mortality (p = 0.013) after adjusting for age, clinical prognostic factors, European System for Cardiac Operative Risk Evaluation II, dimensionless velocity index, left ventricular mass index, left ventricular ejection fraction, heart rate, time, type of aortic valve intervention, and SVi (p = 0.59). In patients with low-gradient, low valve area aortic stenosis undergoing aortic valve intervention, low FR, not low SVi, was an independent predictor of medium-term mortality. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

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.

Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

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

Dial, Christian; Weiss, Elisabeth; Hugo, Geoffrey D., E-mail: gdhugo@vcu.edu

Purpose: To quantify the potential benefit associated with daily replanning in lung cancer in terms of normal tissue dose sparing and to characterize the tradeoff between adaptive benefit and replanning frequency. Methods: A set of synthetic images and contours, derived from weekly active breathing control images of 12 patients who underwent radiation therapy treatment for nonsmall cell lung cancer, is generated for each fraction of treatment using principal component analysis in a way that preserves temporal anatomical trends (e.g., tumor regression). Daily synthetic images and contours are used to simulate four different treatment scenarios: (1) a “no-adapt” scenario that simulatesmore » delivery of an initial plan throughout treatment, (2) a “midadapt” scenario that implements a single replan for fraction 18, (3) a “weekly adapt” scenario that simulates weekly adaptations, and (4) a “full-adapt” scenario that simulates daily replanning. An initial intensity modulated radiation therapy plan is created for each patient and replanning is carried out in an automated fashion by reoptimizing beam apertures and weights. Dose is calculated on each image and accumulated to the first in the series using deformable mappings utilized in synthetic image creation for comparison between simulated treatments. Results: Target coverage was maintained and cord tolerance was not exceeded for any of the adaptive simulations. Average reductions in mean lung dose (MLD) and volume of lung receiving 20 Gy or more (V20{sub lung}) were 65 ± 49 cGy (p = 0.000 01) and 1.1% ± 1.2% (p = 0.0006), respectively, for all patients. The largest reduction in MLD for a single patient was 162 cGy, which allowed an isotoxic escalation of the target dose of 1668 cGy. Average reductions in cord max dose, mean esophageal dose (MED), dose received by 66% of the heart (D66{sub heart}), and dose received by 33% of the heart (D33{sub heart}), were 158 ± 280, 117 ± 121, 37 ± 77, and 99 ± 120 cGy, respectively. Average incremental reductions in MLD for the midadapt, weekly adapt, and full-adapt treatments were 38, 18, and 8 cGy, respectively. Incremental reductions in MED for the same treatments were 57, 37, and 23 cGy. Reductions in MLD and MED for the full-adapt treatment were correlated with the absolute decrease in the planning target volume (r = 0.34 and r = 0.26). Conclusions: Adaptive radiation therapy for lung cancer yields clinically relevant reductions in normal tissue doses for frequencies of adaptation ranging from a single replan up to daily replanning. Increased frequencies of adaptation result in additional benefit while magnitude of benefit decreases.« less

Impairment of left ventricular function during coronary angioplastic occlusion evaluated with a nonimaging scintillation probe.

PubMed

Hartmann, A; Maul, F D; Zimny, M; Klepzig, H; Vallbracht, C; Kneissl, H G; Schräder, R; Hör, G; Kaltenbach, M

1991-09-01

Impairment of left ventricular function during controlled myocardial ischemia induced by coronary angioplasty has been reported from angiographic and echocardiographic studies. Ejection fraction, peak ejection, peak filling rates, and end-systolic and end-diastolic volumes were investigated before, during and after coronary occlusion on-line with a nonimaging scintillation probe. The study consisted of 18 patients (mean age 59 +/- 10 years) with coronary artery stenosis of greater than 70%. During balloon inflation of 60 seconds' duration, coronary occlusion pressure was 31.6 +/- 12 mm Hg. There was no significant change in heart rate. Delay between first and second dilatation was 109 +/- 63 seconds. Ejection fraction decreased from 53 +/- 16 to 40 +/- 12% (first dilatation, p less than 0.01) and to 39 +/- 14% (second dilatation, p less than 0.01) and recovered to 51 +/- 16% 5 minutes after the second dilatation. Peak ejection rate was significantly reduced during the first and second balloon inflations. Peak filling rate decreased from 2.5 +/- 0.8 to 2.0 +/- 0.7 end-diastolic volume.s-1 (first dilatation, p less than 0.01) and to 1.8 +/- 0.7 end-diastolic volume.s-1 (second dilatation, p less than 0.01) and remained reduced at 2.2 +/- 0.7 end-diastolic volume.s-1 (p = not significant) at 5 minutes after the second dilatation. End-systolic and end-diastolic volumes increased significantly during the first and second dilatations and returned to normal after dilatation. It is concluded that short, controlled myocardial ischemia during coronary angioplasty leads to a decrease in systolic and diastolic left ventricular function. Sequential dilatations do not further decrease function if a sufficient interval is kept.

General anesthesia suppresses normal heart rate variability in humans

NASA Astrophysics Data System (ADS)

Matchett, Gerald; Wood, Philip

2014-06-01

The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.

Quantitative analysis of hypertrophic myocardium using diffusion tensor magnetic resonance imaging

PubMed Central

Tran, Nicholas; Giannakidis, Archontis; Gullberg, Grant T.; Seo, Youngho

2016-01-01

Abstract. Systemic hypertension is a causative factor in left ventricular hypertrophy (LVH). This study is motivated by the potential to reverse or manage the dysfunction associated with structural remodeling of the myocardium in this pathology. Using diffusion tensor magnetic resonance imaging, we present an analysis of myocardial fiber and laminar sheet orientation in ex vivo hypertrophic (6 SHR) and normal (5 WKY) rat hearts using the covariance of the diffusion tensor. First, an atlas of normal cardiac microstructure was formed using the WKY b0 images. Then, the SHR and WKY b0 hearts were registered to the atlas. The acquired deformation fields were applied to the SHR and WKY heart tensor fields followed by the preservation of principal direction (PPD) reorientation strategy. A mean tensor field was then formed from the registered WKY tensor images. Calculating the covariance of the registered tensor images about this mean for each heart, the hypertrophic myocardium exhibited significantly increased myocardial fiber derangement (p=0.017) with a mean dispersion of 38.7 deg, and an increased dispersion of the laminar sheet normal (p=0.030) of 54.8 deg compared with 34.8 deg and 51.8 deg, respectively, in the normal hearts. Results demonstrate significantly altered myocardial fiber and laminar sheet structure in rats with hypertensive LVH. PMID:27872872

Dose to mass for evaluation and optimization of lung cancer radiation therapy.

PubMed

Tyler Watkins, William; Moore, Joseph A; Hugo, Geoffrey D; Siebers, Jeffrey V

2017-11-01

To evaluate potential organ at risk dose-sparing by using dose-mass-histogram (DMH) objective functions compared with dose-volume-histogram (DVH) objective functions. Treatment plans were retrospectively optimized for 10 locally advanced non-small cell lung cancer patients based on DVH and DMH objectives. DMH-objectives were the same as DVH objectives, but with mass replacing volume. Plans were normalized to dose to 95% of the PTV volume (PTV-D95v) or mass (PTV-D95m). For a given optimized dose, DVH and DMH were intercompared to ascertain dose-to-volume vs. dose-to-mass differences. Additionally, the optimized doses were intercompared using DVH and DMH metrics to ascertain differences in optimized plans. Mean dose to volume, D v ‾, mean dose to mass, D M ‾, and fluence maps were intercompared. For a given dose distribution, DVH and DMH differ by >5% in heterogeneous structures. In homogeneous structures including heart and spinal cord, DVH and DMH are nearly equivalent. At fixed PTV-D95v, DMH-optimization did not significantly reduce dose to OARs but reduced PTV-D v ‾ by 0.20±0.2Gy (p=0.02) and PTV-D M ‾ by 0.23±0.3Gy (p=0.02). Plans normalized to PTV-D95m also result in minor PTV dose reductions and esophageal dose sparing (D v ‾ reduced 0.45±0.5Gy, p=0.02 and D M ‾ reduced 0.44±0.5Gy, p=0.02) compared to DVH-optimized plans. Optimized fluence map comparisons indicate that DMH optimization reduces dose in the periphery of lung PTVs. DVH- and DMH-dose indices differ by >5% in lung and lung target volumes for fixed dose distributions, but optimizing DMH did not reduce dose to OARs. The primary difference observed in DVH- and DMH-optimized plans were variations in fluence to the periphery of lung target PTVs, where low density lung surrounds tumor. Copyright © 2017 Elsevier B.V. All rights reserved.

Features of Heart Rate Variability Capture Regulatory Changes During Kangaroo Care in Preterm Infants.

PubMed

Kommers, Deedee R; Joshi, Rohan; van Pul, Carola; Atallah, Louis; Feijs, Loe; Oei, Guid; Bambang Oetomo, Sidarto; Andriessen, Peter

2017-03-01

To determine whether heart rate variability (HRV) can serve as a surrogate measure to track regulatory changes during kangaroo care, a period of parental coregulation distinct from regulation within the incubator. Nurses annotated the starting and ending times of kangaroo care for 3 months. The pre-kangaroo care, during-kangaroo care, and post-kangaroo care data were retrieved in infants with at least 10 accurately annotated kangaroo care sessions. Eight HRV features (5 in the time domain and 3 in the frequency domain) were used to visually and statistically compare the pre-kangaroo care and during-kangaroo care periods. Two of these features, capturing the percentage of heart rate decelerations and the extent of heart rate decelerations, were newly developed for preterm infants. A total of 191 kangaroo care sessions were investigated in 11 preterm infants. Despite clinically irrelevant changes in vital signs, 6 of the 8 HRV features (SD of normal-to-normal intervals, root mean square of the SD, percentage of consecutive normal-to-normal intervals that differ by >50 ms, SD of heart rate decelerations, high-frequency power, and low-frequency/high-frequency ratio) showed a visible and statistically significant difference (P <.01) between stable periods of kangaroo care and pre-kangaroo care. HRV was reduced during kangaroo care owing to a decrease in the extent of transient heart rate decelerations. HRV-based features may be clinically useful for capturing the dynamic changes in autonomic regulation in response to kangaroo care and other changes in environment and state. Copyright © 2016 Elsevier Inc. All rights reserved.

Relationship of echocardiographic indices to pulmonary capillary wedge pressures in healthy volunteers

NASA Technical Reports Server (NTRS)

Firstenberg, M. S.; Levine, B. D.; Garcia, M. J.; Greenberg, N. L.; Cardon, L.; Morehead, A. J.; Zuckerman, J.; Thomas, J. D.

2000-01-01

OBJECTIVES: We sought to determine the relationship between different echocardiographic indices and pulmonary capillary wedge pressures (PCWP) in normal volunteers. BACKGROUND: Indices based on tissue Doppler (TDE) and color M-mode (CMM) echocardiography have been proposed to reflect left (LV) ventricular filling pressures. These include the ratio of early diastolic transmitral velocity (E) to early myocardial velocity measured by TDE (E') and the ratio of E to the wave propagation velocity (Vp) measured from CMM images. These indices, however, have not been validated in normal individuals. METHODS: We studied seven volunteers during two phases of preload altering maneuvers, baseline, with two stages of lower body negative pressure, and repeat baseline with two stages of volume loading. The PCWP obtained from right heart catheterization was compared with diastolic indices using pulsed Doppler, TDE and CMM echocardiography. RESULTS: The PCWP ranged from 2.2 to 23.5 mm Hg. During preload alterations, significant changes in E and septal E' (both p < 0.05) but not lateral E' or Vp were observed. Furthermore, E, septal E' and E/Vp correlated with PCWP (all r > 0.80) but not combined E and TDE indices (both r < 0.15). Within individuals, a similar linear relationship was observed among E/Vp, E and septal E' (average r > 0.80). CONCLUSIONS: In subjects without heart disease, E, septal E' and E/Vp correlate with PCWP. Because the influence of ventricular relaxation is minimized, the ratio E/Vp may be the best overall index of LV filling pressures.

A Prediction Formula for Double Product in Pregnancy.

PubMed

Teli, Anita; Bagali, Shrilaxmi; Ghatanatti, Ravi

2016-02-01

Maternal cardiovascular changes in pregnancy are numerous and increase in double product throughout pregnancy is the part of the same process. Double product is a cardinal surrogate of the myocardial oxygen demand and cardiac workload. It is the product of heart rate and systolic blood pressure and an important determinant of cardiovascular risk in hypertensive patients. This study was intended to determine the double product by comparing normal individuals with different trimesters of pregnancy. A cross sectional study was conducted in 220 healthy women in the age range of 18-35 years with 60 subjects each in 1(st), 2(nd) and 3(rd) trimesters and 40 non pregnant subjects as control group. Cardiovascular parameters were recorded in both the groups. Statistical analysis was done by comparison of parameters using one-way ANOVA and post-hoc by Tukey-Krammer test. Correlation of double product and weeks of pregnancy was done using Pearson's correlation. Regression analysis was done to know the predictor of double product. It was observed that there was statistically very highly significant increase (p=0.000) in the double product throughout the pregnancy and duration of pregnancy was found to be the predictor of the product. The increase in the double product is due to increase in heart rate and stroke volume. Double product is the useful predictor for early identification of preeclampsia and acute myocardial infarction in pregnant women when compared to normal non- pregnant women and hence helps in the early management of complications.

High-resolution echocardiography

NASA Technical Reports Server (NTRS)

Nathan, R.

1979-01-01

High resolution computer aided ultrasound system provides two-and three-dimensional images of beating heart from many angles. System provides means for determining whether small blood vessels around the heart are blocked or if heart wall is moving normally without interference of dead and noncontracting muscle tissue.

Prior publication productivity, grant percentile ranking, and topic-normalized citation impact of NHLBI cardiovascular R01 grants.

PubMed

Kaltman, Jonathan R; Evans, Frank J; Danthi, Narasimhan S; Wu, Colin O; DiMichele, Donna M; Lauer, Michael S

2014-09-12

We previously demonstrated absence of association between peer-review-derived percentile ranking and raw citation impact in a large cohort of National Heart, Lung, and Blood Institute cardiovascular R01 grants, but we did not consider pregrant investigator publication productivity. We also did not normalize citation counts for scientific field, type of article, and year of publication. To determine whether measures of investigator prior productivity predict a grant's subsequent scientific impact as measured by normalized citation metrics. We identified 1492 investigator-initiated de novo National Heart, Lung, and Blood Institute R01 grant applications funded between 2001 and 2008 and linked the publications from these grants to their InCites (Thompson Reuters) citation record. InCites provides a normalized citation count for each publication stratifying by year of publication, type of publication, and field of science. The coprimary end points for this analysis were the normalized citation impact per million dollars allocated and the number of publications per grant that has normalized citation rate in the top decile per million dollars allocated (top 10% articles). Prior productivity measures included the number of National Heart, Lung, and Blood Institute-supported publications each principal investigator published in the 5 years before grant review and the corresponding prior normalized citation impact score. After accounting for potential confounders, there was no association between peer-review percentile ranking and bibliometric end points (all adjusted P>0.5). However, prior productivity was predictive (P<0.0001). Even after normalizing citation counts, we confirmed a lack of association between peer-review grant percentile ranking and grant citation impact. However, prior investigator publication productivity was predictive of grant-specific citation impact. © 2014 American Heart Association, Inc.

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.

A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy.

PubMed

Alter, P; Rupp, H; Rominger, M B; Klose, K J; Maisch, B

2008-01-01

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.

Comparison of electron-beam and ungated helical CT in detecting coronary arterial calcification by using a working heart phantom and artificial coronary arteries.

PubMed

Hopper, Kenneth D; Strollo, Diane C; Mauger, David T

2002-02-01

To determine the sensitivity and specificity of cardiac gated electron-beam computed tomography (CT) and ungated helical CT in detecting and quantifying coronary arterial calcification (CAC) by using a working heart phantom and artificial coronary arteries. A working heart phantom simulating normal cardiac motion and providing attenuation equal to that of an adult thorax was used. Thirty tubes with a 3-mm inner diameter were internally coated with pulverized human cortical bone mixed with epoxy glue to simulate minimal (n = 10), mild (n = 10), or severe (n = 10) calcified plaques. Ten additional tubes were not coated and served as normal controls. The tubes were attached to the same location on the phantom heart and scanned with electron-beam CT and helical CT in horizontal and vertical planes. Actual plaque calcium content was subsequently quantified with atopic spectroscopy. Two blinded experienced radiologic imaging teams, one for each CT system, separately measured calcium content in the model vessels by using a Hounsfield unit threshold of 130 or greater. The sensitivity and specificity of electron-beam CT in detecting CAC were 66.1% and 80.0%, respectively. The sensitivity and specificity of helical CT were 96.4% and 95.0%, respectively. Electron-beam CT was less reliable when vessels were oriented vertically (sensitivity and specificity, 71.4% and 70%; 95% CI: 39.0%, 75.0%) versus horizontally (sensitivity and specificity, 60.7% and 90.0%; 95% CI: 48.0%, 82.0%). When a correction factor was applied, the volume of calcified plaque was statistically better quantified with helical CT than with electron-beam CT (P =.004). Ungated helical CT depicts coronary arterial calcium better than does gated electron-beam CT. When appropriate correction factors are applied, helical CT is superior to electron-beam CT in quantifying coronary arterial calcium. Although further work must be done to optimize helical CT grading systems and scanning protocols, the data of this study demonstrated helical CT's inherent advantage over currently commercially available electron-beam CT systems in CAC detection and quantification.

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

The paradox of left ventricular assist device unloading and myocardial recovery in end-stage dilated cardiomyopathy: implications for heart failure in the elderly.

PubMed

Butler, Craig R; Jugdutt, Bodh I

2012-09-01

Dilated cardiomyopathy (DCM) is a common debilitating condition with limited therapeutic options besides heart transplantation or palliation. It is characterized by maladaptive remodeling of cardiomyocytes, extracellular collagen matrix (ECCM) and left ventricular (LV) geometry which contributes to further dysfunction. LV assist devices (LVADs) can reverse adverse remodeling in end-stage DCM. However, there is a disconnect between the benefits of prolonged unloading with LVAD at molecular and cellular levels and the low rate of bridge to recovery (BTR). Potential explanations for this paradox include insufficient reverse ECCM remodeling and/or excessive reverse cardiomyocyte remodeling with atrophy. LVAD therapy is associated with decreased collagen turnover and cross-linking and increased tissue angiotensin II (AngII), whereas LVAD combined with angiotensin-converting enzyme inhibition results in decreased tissue AngII and collagen cross-linking, normalizes LV end-diastolic pressure volume relationships and is associated with modestly higher rates of BTR. Much remains to be learned about ventricular reverse remodeling after LVAD. This can be facilitated through systematic collection and comparison of recovered and unrecovered myocardium. Importantly, vigilant monitoring for ventricular recovery among LVAD patients is needed, particularly in older patients receiving LVAD for destination therapy. In addition, prospective multicenter trials are needed to clarify the potential benefit of concomitant heart failure therapy with selective β2 agonism on ventricular recovery.

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.

UCP3 Ablation Exacerbates High-Salt Induced Cardiac Hypertrophy and Cardiac Dysfunction.

PubMed

Lang, Hongmei; Xiang, Yang; Ai, Zhihua; You, Zhiqing; Jin, Xiaolan; Wan, Yong; Yang, Yongjian

2018-04-20

Excessive salt intake and left ventricular hypertrophy (LVH) are both critical for the development of hypertension and heart failure. The uncoupling protein 3 (UCP3) plays a cardio-protective role in early heart failure development. However, the potential role for UCP3 in salt intake and LVH is unclear. UCP3-/- and C57BL/6 mice were placed on either a normal-salt (NS, 0.5%) or a high-salt (HS, 8%) diet for 24 weeks. The cardiac function, endurance capacity, energy expenditure, and mitochondrial functional capacity were measured in each group. Elevated blood pressure was only observed in HS-fed UCP3-/- mice. High salt induced cardiac hypertrophy and dysfunction were observed in both C57BL/6 and UCP3-/- mice. However, the cardiac lesions were more profound in HS-fed UCP3-/- mice. Furthermore, HS-fed UCP3-/-mice experienced more severe mitochondrial respiratory dysfunction compared with HS-fed C57BL/6 mice, represented by the decreased volume of oxygen consumption and heat production at the whole-body level. UCP3 protein was involved in the incidence of high-salt induced hypertension and the progression of cardiac dysfunction in the early stages of heart failure. UCP3 ablation exacerbated high-salt-induced cardiac hypertrophy and cardiac dysfunction. © 2018 The Author(s). Published by S. Karger AG, Basel.

Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast-enhanced magnetic resonance imaging.

PubMed

Nielsen, Gitte; Fritz-Hansen, Thomas; Dirks, Christina G; Jensen, Gorm B; Larsson, Henrik B W

2004-09-01

To investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast-enhanced MRI sequence was applied to patients with acute myocardial infarction. Seven patients with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five slices, each having 60 sectors, provided an estimation of the severity and extent of the perfusion deficiency. Reperfusion was assessed both by noninvasive criteria and by coronary angiography (CAG). The Ki maps clearly delineated the infarction in all patients. Thrombolytic treatment was clearly beneficial in one case, but had no effect in the two other cases. Over the time-course of the study, normal perfusion values were not reestablished following thrombolytic treatment in all cases investigated. This study shows that quantitative MRI perfusion values can be obtained from acutely ill patients following acute myocardial infarction. The technique provides information on both the volume and severity of affected myocardial tissue, enabling the power of treatment regimes to be assessed objectively, and this approach should aid individual patient stratification and prognosis. Copyright 2004 Wiley-Liss, Inc.

Response of the oxygen uptake efficiency slope to orthotopic heart transplantation: lack of correlation with changes in central hemodynamic parameters and resting lung function.

PubMed

Van Laethem, Christophe; Goethals, Marc; Verstreken, Sofie; Walravens, Maarten; Wellens, Francis; De Proft, Margot; Bartunek, Jozef; Vanderheyden, Marc

2007-09-01

Recently, a new linear measure of ventilatory response to exercise, the oxygen uptake efficiency slope (OUES), was proposed in the evaluation of heart failure patients. No data are available on the response of the OUES after orthotopic heart transplantation (HTx). Thirty patients who underwent HTx between 1999 and 2003 were included in the study. Data from maximal cardiopulmonary exercise test, resting pulmonary function and hemodynamic assessment were collected before the transplant at time of screening and 1 year after HTx. During the first year after HTx, OUES and normalized OUES for body weight (OUES/kg) increased significantly from 15.6 +/- 4.9 to 19.7 +/- 4.8 (p < 0.05). Changes in OUES/kg were significantly correlated with changes in peak VO2, VAT and peak VE, and inversely to changes in peak VD/VT, but not to changes in VE/VCO2 slope (all p < 0.05). Changes in OUES or OUES/kg did not correlate with any changes in measures of resting lung volumes or capacities and measures of central hemodynamic function after HTx. OUES improved significantly after HTx, but, similar to other exercise parameters, remained considerably impaired. The changes in OUES were highly correlated with the improvements in other exercise variables, but did not correlate with marked improvements in central hemodynamics or resting lung function.

Size and shape of right heart chambers in mitral valve regurgitation in small-breed dogs.

PubMed

Carlsson, C; Häggström, J; Eriksson, A; Järvinen, A -K; Kvart, C; Lord, P

2009-01-01

The contribution of right heart (RH) chamber enlargement to general heart enlargement seen on thoracic radiographs in mitral regurgitation (MR) is not known. To determine the size and shape of the RH chambers in normal dogs and dogs with varying degrees of MR. Fifty-four privately owned dogs: 13 normal, 41 with varying degrees of MR including 25 with congestive heart failure (CHF). Archived first pass radionuclide angiocardiograms were used to produce static images of the RH and left heart (LH) chambers. Indexes of size and shape of the RH and LH chambers were related to severity of MR determined by heart rate-normalized pulmonary transit time (nPTT), vertebral heart scale (VHS), and clinical status. RH shape was measured by a circularity index of RH short axis/long axis. A 2nd degree polynomial fit best described the ratios; RH/LH dimension to nPTT (R(2)= 0.62) and to VHS (R(2)= 0.43), RH/LH area to nPTT (R(2)= 0.64) and to VHS (R(2)= 0.58), all P < .001. RH circularity was decreased in CHF, P < .001. In CHF, the RH chambers of 16 dogs were both flattened and enlarged, whereas 9 had convex septal borders. RH chambers are not significantly dilated in dogs with mild to moderate MR without CHF. In CHF, RH chambers enlarge and also may be compressed by the LH chambers. Pulmonary hypertension probably is present in some dogs with CHF. Increased sternal contact is not a useful sign of right-sided heart dilatation in MR.

Beneficial effect of zinc chloride and zinc ionophore pyrithione on attenuated cardioprotective potential of preconditioning phenomenon in STZ-induced diabetic rat heart.

PubMed

Jamwal, Sumit; Kumar, Kushal; Reddy, B V Krishna

2016-05-01

Ischemic preconditioning (IPC) is well demonstrated to produce cardioprotection by phosphorylation and subsequent inactivation of glycogen synthase kinase-3β (GSk-3β) in the normal rat heart, but its effect is attenuated in the diabetic rat heart. This study was designed to investigate the effect of zinc chloride and zinc ionophore pyrithione (ZIP) on the attenuated cardioprotective potential of IPC in the diabetic rat heart. Diabetes mellitus (DM) was induced by a single intraperitoneal administration of streptozotocin (STZ) (50 mg/kg; i.p). The isolated perfused rat heart was subjected to 30 minutes of ischemia followed by 120 minutes of reperfusion. Myocardial infarct size was estimated by triphenyltetrazolium chloride (TTC) staining and cardiac injury was measured by estimating lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in the coronary effluent. Also, GSK-3β was measured and neutrophil accumulation was measured by estimating myeloperoxidase (MPO) levels. IPC significantly decreased the myocardial infarct size, the release of LDH and CK-MB, the GSK-3β levels and the MPO levels in the normal rat heart. Pre- and post-ischemic treatment with zinc chloride and zinc ionophore pyrithione (ZIP) in the normal and diabetic rat hearts significantly decreased the myocardial infarct size, the level of CK-MB and LDH in the coronary effluent and GSK-3β and MPO levels. Our results suggest that pharmacological preconditioning with zinc chloride and ZIP significantly restored the attenuated cardioprotective potential of IPC in the diabetic rat heart. © The Author(s) 2015.

Emotional reaction evaluation provoked by the vestibular caloric test through physiological variables monitoring.

PubMed

Barona-de-Guzmán, Rafael; Krstulovic-Roa, Claudio; Donderis-Malea, Elena; Barona-Lleó, Luz

2018-03-08

The emotional evaluation of the causes of vertigo is made using the clinical records and several subjective questionnaires. The aim of the present study is to evaluate the emotional response objectively, in normal subjects, during an induced vertigo crisis. A caloric vestibular test with cold water was performed on 30 healthy subjects. The following physiological parameters were monitored during the 60seconds prior to and the 60seconds after the stimulation: Skin Conductivity, Peripheral Pulse Volume, Body Temperature, Muscle Contraction, Heart Rate, and Respiratory Rate. The maximum angular speed of the nystagmus slow phase at each stimulation was assessed. Skin conductance presented a statistically significant increase during the vertigo crisis in relation to the prior period while the peripheral pulse volume presented a statistically significant decrease. There was no relationship between the slow phase of the provoked nystagmus angular speed and skin conductance and peripheral pulse volume changes. The decrease in peripheral pulse volume was significantly higher in the second vertigo crisis. Skin conductance and peripheral pulse volume changed significantly during a vertigo crisis. There was no relation between the provoked vertiginous crisis intensity and the changes produced in those variables. The stress generated by the caloric stimulation is higher in the second crisis, when the subject has experience of the vertigo caused by the stimulation. Copyright © 2018 Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. Publicado por Elsevier España, S.L.U. All rights reserved.

Exercises in anatomy: the normal heart.

PubMed

Anderson, Robert H; Sarwark, Anne; Spicer, Diane E; Backer, Carl L

2014-01-01

In this series of videoclips, we analyze the anatomy of the normal heart. We begin our overview by emphasizing the need, in the current era, to describe the heart in attitudinally appropriate fashion. Increasingly, clinicians are demonstrating the features of the heart as it is located within the body. It is no longer satisfactory, therefore, to describe these components in a ‘Valentine’ fashion, as continues to be the case in most textbooks of normal or cardiac anatomy. We then emphasize the importance of the so-called morphological method, which states that structures within the heart should be defined on the basis of their own intrinsic morphology, and not according to other parts, which are themselves variable. We continue by using this concept to show how the appendages serve to distinguish between the atrial chambers, while the apical trabecular components provide the features to distinguish the ventricles. We then return to the cardiac chambers, emphasizing features of surgical significance, in particular the locations of the cardiac conduction tissues. We proceed by examining the cardiac valves, and conclude by providing a detailed analysis of the septal structures. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Increased heart rate after exercise facilitates the processing of fearful but not disgusted faces.

PubMed

Pezzulo, G; Iodice, P; Barca, L; Chausse, P; Monceau, S; Mermillod, M

2018-01-10

Embodied theories of emotion assume that emotional processing is grounded in bodily and affective processes. Accordingly, the perception of an emotion re-enacts congruent sensory and affective states; and conversely, bodily states congruent with a specific emotion facilitate emotional processing. This study tests whether the ability to process facial expressions (faces having a neutral expression, expressing fear, or disgust) can be influenced by making the participants' body state congruent with the expressed emotion (e.g., high heart rate in the case of faces expressing fear). We designed a task requiring participants to categorize pictures of male and female faces that either had a neutral expression (neutral), or expressed emotions whose linkage with high heart rate is strong (fear) or significantly weaker or absent (disgust). Critically, participants were tested in two conditions: with experimentally induced high heart rate (Exercise) and with normal heart rate (Normal). Participants processed fearful faces (but not disgusted or neutral faces) faster when they were in the Exercise condition than in the Normal condition. These results support the idea that an emotionally congruent body state facilitates the automatic processing of emotionally-charged stimuli and this effect is emotion-specific rather than due to generic factors such as arousal.

Accelerating cine-MR Imaging in Mouse Hearts Using Compressed Sensing

PubMed Central

Wech, Tobias; Lemke, Angela; Medway, Debra; Stork, Lee-Anne; Lygate, Craig A; Neubauer, Stefan; Köstler, Herbert; Schneider, Jürgen E

2011-01-01

Purpose To combine global cardiac function imaging with compressed sensing (CS) in order to reduce scan time and to validate this technique in normal mouse hearts and in a murine model of chronic myocardial infarction. Materials and Methods To determine the maximally achievable acceleration factor, fully acquired cine data, obtained in sham and chronically infarcted (MI) mouse hearts were 2–4-fold undersampled retrospectively, followed by CS reconstruction and blinded image segmentation. Subsequently, dedicated CS sampling schemes were implemented at a preclinical 9.4 T magnetic resonance imaging (MRI) system, and 2- and 3-fold undersampled cine data were acquired in normal mouse hearts with high temporal and spatial resolution. Results The retrospective analysis demonstrated that an undersampling factor of three is feasible without impairing accuracy of cardiac functional parameters. Dedicated CS sampling schemes applied prospectively to normal mouse hearts yielded comparable left-ventricular functional parameters, and intra- and interobserver variability between fully and 3-fold undersampled data. Conclusion This study introduces and validates an alternative means to speed up experimental cine-MRI without the need for expensive hardware. J. Magn. Reson. Imaging 2011. © 2011 Wiley Periodicals, Inc. PMID:21932360

A method for deriving a 4D-interpolated balanced planning target for mobile tumor radiotherapy.

PubMed

Roland, Teboh; Hales, Russell; McNutt, Todd; Wong, John; Simari, Patricio; Tryggestad, Erik

2012-01-01

Tumor control and normal tissue toxicity are strongly correlated to the tumor and normal tissue volumes receiving high prescribed dose levels in the course of radiotherapy. Planning target definition is, therefore, crucial to ensure favorable clinical outcomes. This is especially important for stereotactic body radiation therapy of lung cancers, characterized by high fractional doses and steep dose gradients. The shift in recent years from population-based to patient-specific treatment margins, as facilitated by the emergence of 4D medical imaging capabilities, is a major improvement. The commonly used motion-encompassing, or internal-target volume (ITV), target definition approach provides a high likelihood of coverage for the mobile tumor but inevitably exposes healthy tissue to high prescribed dose levels. The goal of this work was to generate an interpolated balanced planning target that takes into account both tumor coverage and normal tissue sparing from high prescribed dose levels, thereby improving on the ITV approach. For each 4DCT dataset, 4D deformable image registration was used to derive two bounding targets, namely, a 4D-intersection and a 4D-composite target which minimized normal tissue exposure to high prescribed dose levels and maximized tumor coverage, respectively. Through definition of an "effective overlap volume histogram" the authors derived an "interpolated balanced planning target" intended to balance normal tissue sparing from prescribed doses with tumor coverage. To demonstrate the dosimetric efficacy of the interpolated balanced planning target, the authors performed 4D treatment planning based on deformable image registration of 4D-CT data for five previously treated lung cancer patients. Two 4D plans were generated per patient, one based on the interpolated balanced planning target and the other based on the conventional ITV target. Plans were compared for tumor coverage and the degree of normal tissue sparing resulting from the new approach was quantified. Analysis of the 4D dose distributions from all five patients showed that while achieving tumor coverage comparable to the ITV approach, the new planning target definition resulted in reductions of lung V(10), V(20), and V(30) of 6.3% ± 1.7%, 10.6% ± 3.9%, and 12.9% ± 5.5%, respectively, as well as reductions in mean lung dose, mean dose to the GTV-ring and mean heart dose of 8.8% ± 2.5%, 7.2% ± 2.5%, and 10.6% ± 3.6%, respectively. The authors have developed a simple and systematic approach to generate a 4D-interpolated balanced planning target volume that implicitly incorporates the dynamics of respiratory-organ motion without requiring 4D-dose computation or optimization. Preliminary results based on 4D-CT data of five previously treated lung patients showed that this new planning target approach may improve normal tissue sparing without sacrificing tumor coverage.

Acute effect of L-arginine on hemodynamics and vascular capacitance in the canine pacing model of heart failure.

PubMed

Ogilvie, R I; Zborowska-Sluis, D

1995-09-01

The effect of L-arginine, 250 mg/kg over 10 min, on hemodynamics and venous function was studied in nine splenectomized dogs under light pentobarbital anesthesia before and after 17 +/- 1 days of rapid right ventricular pacing (RRVP) at 250 beats/min. Chronic RRVP induced mild congestive heart failure with increased mean circulatory filling (Pmcf), right atrial (Pra) and pulmonary capillary wedge pressures (Ppcw), and reduced cardiac output (CO). During the development of heart failure, total vascular compliance assessed from Pmcf-blood volume relationships during circulatory arrest was unchanged, but total vascular capacitance was markedly reduced, with an increase in stressed and reduction in unstressed blood volumes. At baseline but not after RRVP, L-arginine increased CO and reduced pulmonary vascular resistance. There were no significant changes in Pra, Ppcw, or total peripheral resistance. L-Arginine failed to alter total vascular compliance and capacitance or central blood volume in the baseline or failure state. These results do not support the hypothesis that increased Pmcf and reduced total vascular capacitance in the early stages of pacing-induced heart failure are caused by reduced substrate availability for or an endogenous competitive antagonist of NO synthase in venous endothelial cells.

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.

hnRNP U protein is required for normal pre-mRNA splicing and postnatal heart development and function.

PubMed

Ye, Junqiang; Beetz, Nadine; O'Keeffe, Sean; Tapia, Juan Carlos; Macpherson, Lindsey; Chen, Weisheng V; Bassel-Duby, Rhonda; Olson, Eric N; Maniatis, Tom

2015-06-09

We report that mice lacking the heterogeneous nuclear ribonucleoprotein U (hnRNP U) in the heart develop lethal dilated cardiomyopathy and display numerous defects in cardiac pre-mRNA splicing. Mutant hearts have disorganized cardiomyocytes, impaired contractility, and abnormal excitation-contraction coupling activities. RNA-seq analyses of Hnrnpu mutant hearts revealed extensive defects in alternative splicing of pre-mRNAs encoding proteins known to be critical for normal heart development and function, including Titin and calcium/calmodulin-dependent protein kinase II delta (Camk2d). Loss of hnRNP U expression in cardiomyocytes also leads to aberrant splicing of the pre-mRNA encoding the excitation-contraction coupling component Junctin. We found that the protein product of an alternatively spliced Junctin isoform is N-glycosylated at a specific asparagine site that is required for interactions with specific protein partners. Our findings provide conclusive evidence for the essential role of hnRNP U in heart development and function and in the regulation of alternative splicing.

Fat in the heart: The enzymatic machinery regulating cardiac triacylglycerol metabolism.

PubMed

Heier, Christoph; Haemmerle, Guenter

2016-10-01

The heart predominantly utilizes fatty acids (FAs) as energy substrate. FAs that enter cardiomyocytes can be activated and directly oxidized within mitochondria (and peroxisomes) or they can be esterified and intracellularly deposited as triacylglycerol (TAG) often simply referred to as fat. An increase in cardiac TAG can be a signature of the diseased heart and may implicate a minor role of TAG synthesis and breakdown in normal cardiac energy metabolism. Often overlooked, the heart has an extremely high TAG turnover and the transient deposition of FAs within the cardiac TAG pool critically determines the availability of FAs as energy substrate and signaling molecules. We herein review the recent literature regarding the enzymes and co-regulators involved in cardiomyocyte TAG synthesis and catabolism and discuss the interconnection of these metabolic pathways in the normal and diseased heart. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

[3H]-nitrendipine binding in membranes obtained from hypoxic and reoxygenated heart.

PubMed

Matucci, R; Bennardini, F; Sciammarella, M L; Baccaro, C; Stendardi, I; Franconi, F; Giotti, A

1987-04-01

We compared the binding properties of [3H]-nitrendipine in heart membranes from normal guinea-pig heart and from hypoxic or hypoxic and reoxygenated heart. The [3H]-nitrendipine binds a single class of high capacity (Bmax 667.2 +/- 105.2) with high affinity (KD 0.14 +/- 0.02) binding sites. By contrast, in membranes of hypoxic and reoxygenated heart the Bmax decreases significantly while it remains unaffected during hypoxia. Xanthinoxidase activity is increased in hypoxic-reoxygenated hearts.

Dosimetric Improvements with a Novel Breast Stereotactic Radiotherapy Device for Delivery of Preoperative Partial-Breast Irradiation.

PubMed

Snider, James W; Mutaf, Yildirim; Nichols, Elizabeth; Hall, Andrea; Vadnais, Patrick; Regine, William F; Feigenberg, Steven J

2017-01-01

Partial-breast irradiation (PBI) with external-beam radiotherapy has produced higher than expected rates of fair-to-poor cosmesis. Worsened outcomes have been correlated with larger volumes of breast tissue exposed to radiation. A novel breast-specific stereotactic radiotherapy (BSRT) device (BSRTD) has been developed at our institution and has shown promise in delivering highly conformal dose distributions. We compared normal tissue sparing with this device with that achieved with intensity-modulated radiation therapy (IMRT)-PBI. Fifteen women previously treated with breast conservation therapy were enrolled on an institutional review board-approved protocol. Each of them underwent CT simulation in the prone position using the BSRTD-specific immobilization system. Simulated postoperative and preoperative treatment volumes were generated based on surgical bed/clip position. Blinded planners generated IMRT-PBI plans and BSRT plans for each set of volumes. These plans were compared based on clinically validated markers for cosmetic outcome and toxicity using a Wilcoxon rank-sum test. The BSRT plans consistently reduced the volumes receiving each of several dose levels (Vx) to breast tissue, the chest wall, the lung, the heart, and the skin in both preoperative and postoperative settings (p < 0.05). Preoperative BSRT yielded particularly dramatic improvements. The novel BSRTD has demonstrated significant dosimetric benefits over IMRT-PBI. Further investigation is currently proceeding through initial clinical trials. © 2016 S. Karger AG, Basel.

A Retrospective Evaluation of Echocardiograms to Establish Normative Inferior Vena Cava and Aortic Measurements for Children Younger Than 6 Years.

PubMed

Stenson, Erin K; Punn, Rajesh; Ramsi, Musaab; Kache, Saraswati

2018-02-26

The ability to plot the inferior vena cava (IVC) size on a normal curve for pediatric patients may prove beneficial. First, in patients with normal cardiac anatomy who present in shock, assessing IVC size may be valuable for evaluating the degree of dehydration. Second, in children with heart disease, understanding how a child's IVC size compares to normal could be particularly beneficial for patients with right heart disease. We sought to create normal curves for the IVC and aorta in children younger than 6 years. Data were gathered from 347 echocardiograms of healthy children younger than 6 years in a retrospective study at a quaternary care children's hospital. From the subcostal long- and short-axis images, maximum diameters in the transverse and longitudinal views were obtained for both the IVC and the aorta. Both IVC and aortic dimensions increased in a linear fashion and had excellent correlations with the body surface area, body mass, and height (IVC, r = 0.78-0.81; P < .0001; aorta, r = 0.82-0.86; P < .0001). In children younger than 6 years, the IVC and aorta increase linearly as the children grow. Such normal curves will be beneficial for assessing a pediatric patient's hydration status or right heart function in patients with congenital heart disease. © 2018 by the American Institute of Ultrasound in Medicine.

Reduction of XNkx2-10 expression leads to anterior defects and malformation of the embryonic heart.

PubMed

Allen, Bryan G; Allen-Brady, Kristina; Weeks, Daniel L

2006-10-01

Normal vertebrate heart development depends upon the expression of homeodomain containing proteins related to the Drosophila gene, tinman. In Xenopus laevis, three such genes have been identified in regions that will eventually give rise to the heart, XNkx2-3, XNkx2-5 and XNkx2-10. Although the expression domains of all three overlap in early development, distinctive differences have been noted. By the time the heart tube forms, there is little XNkx2-10 mRNA detected by in situ analysis in the embryonic heart while both XNkx2-3 and XNkx2-5 are clearly present. In addition, unlike XNkx2-3 and XNkx2-5, injection of XNkx2-10 mRNA does not increase the size of the embryonic heart. We have reexamined the expression and potential role of XNkx2-10 in development via oligonucleotide-mediated reduction of XNkx2-10 protein expression. We find that a decrease in XNkx2-10 leads to a broad spectrum of developmental abnormalities including a reduction in heart size. We conclude that XNkx2-10, like XNkx2-3 and XNkx2-5, is necessary for normal Xenopus heart development.

Reduction of XNkx2-10 expression leads to anterior defects and malformation of the embryonic heart

PubMed Central

Allen, Bryan G.; Allen-Brady, Kristina; Weeks, Daniel L.

2007-01-01

Normal vertebrate heart development depends upon the expression of homeodomain containing proteins related to the Drosophila gene, tinman. In Xenopus laevis, three such genes have been identified in regions that will eventually give rise to the heart, XNkx2-3, XNkx2-5 and XNkx2-10. Although the expression domains of all three overlap in early development, distinctive differences have been noted. By the time the heart tube forms, there is little XNkx2-10 mRNA detected by in situ analysis in the embryonic heart while both XNkx2-3 and XNkx2-5 are clearly present. In addition, unlike XNkx2-3 and XNkx2-5, injection of XNkx2-10 mRNA does not increase the size of the embryonic heart. We have reexamined the expression and potential role of XNkx2-10 in development via oligonucleotide-mediated reduction of XNkx2-10 protein expression. We find that a decrease in XNkx2-10 leads to a broad spectrum of developmental abnormalities including a reduction in heart size. We conclude that XNkx2-10, like XNkx2-3 and XNkx2-5, is necessary for normal Xenopus heart development. PMID:16949797

SU-E-T-59: A Novel Multi-Beam Dynamic IMRT with Fixed-Jaw Technique for Left Breast Cancer Patients with Regional Lymph Nodes Radiotherapy

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

Wang, J; Yang, Z; Hu, W

2015-06-15

Purpose: This study was to investigate the dosimetric benefit of a novel intensity modulated radiation therapy (IMRT) technique for irradiating the left breast and regional lymph node (RLN). Methods: The breast and RLN (internal mammary node and periclavicular node) and normal tissue were contoured for 16 consecutive left-sided breast cancer patients previously treated with RT after lumpectomy. Nine equi-spaced fields IMRT (9 -field IMRT), tangential multi-beam IMRT (tangential-IMRT) and IMRT with fixed-jaw technique (FJT-IMRT) were developed and compared with three-dimensional conformal RT (3DCRT). Prescribed dose was 50 Gy in 25 fractions. Dose distributions and dose volume histograms were used tomore » evaluate plans. Results: All IMRTs achieved similar target coverage and substantially reduced heart V30 and V20 compared to the 3DCRT. The average heart mean dose had different changes, which were 9.0Gy for 9-field IMRT, 5.7Gy for tangential-IMRT and 4.2Gy for FJT-IMRT. For the contralateral lung and breast, the 9-field IMRT has the highest mean dose; and the FJT-IMRT and tangential-IMRT had similar lower value. For the thyroid, both 9-field IMRT and FJT-IMRT had similar V30 (20% and 22%) and were significantly lower than that of 3DCRT (34%) and tangential-IMRT (46%). Moreover, the thyroid mean dose of FJT-IMRT is the lowest. For cervical esophagus and humeral head, the FJT-IMRT also had the best sparing. Conclusion: All 9-field IMRT, tangential-IMRT and FJT-IMRT had superiority for targets coverage and substantially reduced the heart volume of high dose irradiation. The FJT-IMRT showed advantages of avoiding the contralateral breast and lung irradiation and decreasing the thyroid, humeral head and cervical esophagus radiation dose at the expense of a slight monitor units (MUs) increasing.« less

Interactive effects of temperature and hypoxia on heart rate and oxygen consumption of the 3-day old chicken embryo.

PubMed

Mortola, Jacopo P; Wills, Kathryn; Trippenbach, Teresa; Al Awam, Khalid

2010-03-01

In the chick embryo at day 3, gas exchange occurs by diffusion and oxygen consumption (V(O(2))) does not depend on the cardiovascular convection of O(2). Whether or not this is the case in hypoxia is not known and represents the aim of the study. The heart of chicken embryos at 72 h (stage HH18) was filmed through a window of the eggshell by a camera attached to a microscope. Stroke volume was estimated from the changes in heart silhouette between systole and diastole. V(O(2))was measured by a closed system methodology. In normoxia, a decrease in temperature (T) from 39 to 31 degrees C had parallel depressant effects on V(O(2))and HR. At 39 degrees C, a progressive decrease in O(2) lowered V(O(2)); HR was maintained until the O(2) threshold of approximately 15%. In severe hypoxia (4% O(2)) V(O(2))and HR were, respectively, approximately 12% and approximately 62% of normoxia. At 32 degrees C the hypoxic threshold for HR was significantly lower. During constant hypoxia (7% O(2)) V(O(2))did not respond to T, while the HR response was preserved. Stroke volume changed little with changes in T or O(2), except at 6 and 4% O(2), when it decreased by approximately 20 and 30%. In embryos growth-retarded because of incubation in chronic hypoxia, V(O(2))and HR responses to T and hypoxia were similar to those of normal embryos. We conclude that in the early embryo during hypoxia cardiovascular O(2) convection is not responsible for the drop in V(O(2)). The generalised hypometabolic response, in combination with the extremely small cardiac V(O(2)), probably explains the minor effects of hypoxia on cardiac activity. Copyright 2009 Elsevier Inc. All rights reserved.

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.

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.

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.

21 CFR 870.5300 - DC-defribrillator (including paddles).

Code of Federal Regulations, 2010 CFR

2010-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

21 CFR 870.5300 - DC-defribrillator (including paddles).

Code of Federal Regulations, 2012 CFR

2012-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

21 CFR 870.5300 - DC-defribrillator (including paddles).

Code of Federal Regulations, 2011 CFR

2011-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

21 CFR 870.5300 - DC-defibrillator (including paddles).

Code of Federal Regulations, 2013 CFR

2013-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

21 CFR 870.5300 - DC-defibrillator (including paddles).

Code of Federal Regulations, 2014 CFR

2014-04-01

... of energy used for defibrillating (restoring normal heart rhythm) the atria or ventricles of the heart or to terminate other cardiac arrhythmias. This generic type of device includes low energy... either directly across the heart or on the surface of the body. (2) Classification. Class II (performance...

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.

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

Heart rot of Virginia pine in Maryland

Treesearch

Richard H. Fenton; Frederick H. Berry

1956-01-01

Loggers and sawmill men have been wary of purchasing Virginia pine sawtimber. They point out that a heart rot, locally called "red heart, may spell the difference between profit and loss on a logging job. It is difficult to detect this rot in standing Virginia pine. It is even harder to estimate the volume loss. And total losses can be determined only after...

[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.

Alterations in plasma L-arginine and methylarginines in heart failure and after heart transplantation.

PubMed

Lundgren, Jakob; Sandqvist, Anna; Hedeland, Mikael; Bondesson, Ulf; Wikström, Gerhard; Rådegran, Göran

2018-04-12

Endothelial function, including the nitric oxide (NO)-pathway, has previously been extensively investigated in heart failure (HF). In contrast, studies are lacking on the NO pathway after heart transplantation (HT). We therefore investigated substances in the NO pathway prior to and after HT in relation to hemodynamic parameters. 12 patients (median age 50.0 yrs, 2 females), heart transplanted between June 2012 and February 2014, evaluated at our hemodynamic lab, at rest, prior to HT, as well as four weeks and six months after HT were included. All patients had normal left ventricular function post-operatively and none had post-operative pulmonary hypertension or acute cellular rejection requiring therapy at the evaluations. Plasma concentrations of ADMA, SDMA, L-Arginine, L-Ornithine and L-Citrulline were analyzed at each evaluation. In comparison to controls, the plasma L-Arginine concentration was low and ADMA high in HF patients, resulting in low L-Arginine/ADMA-ratio pre-HT. Already four weeks after HT L-Arginine was normalized whereas ADMA remained high. Consequently the L-Arginine/ADMA-ratio improved, but did not normalize. The biomarkers remained unchanged at the six-month evaluation and the L-Arginine/ADMA-ratio correlated inversely to pulmonary vascular resistance (PVR) six months post-HT. Plasma L-Arginine concentrations normalize after HT. However, as ADMA is unchanged, the L-Arginine/ADMA-ratio remained low and correlated inversely to PVR. Together these findings suggest that (i) the L-Arginine/ADMA-ratio may be an indicator of pulmonary vascular tone after HT, and that (ii) NO-dependent endothelial function is partly restored after HT. Considering the good postoperative outcome, the biomarker levels may be considered "normal" after HT.

Prostacyclins have no direct inotropic effect on isolated atrial strips from the normal and pressure-overloaded human right heart.

PubMed

Holmboe, Sarah; Andersen, Asger; Jensen, Rebekka V; Kimose, Hans Henrik; Ilkjær, Lars B; Shen, Lei; Clapp, Lucie H; Nielsen-Kudsk, Jens Erik

2017-01-01

Prostacyclins are vasodilatory agents used in the treatment of pulmonary arterial hypertension. The direct effects of prostacyclins on right heart function are still not clarified. The aim of this study was to investigate the possible direct inotropic properties of clinical available prostacyclin mimetics in the normal and the pressure-overloaded human right atrium. Trabeculae from the right atrium were collected during surgery from chronic thromboembolic pulmonary hypertension (CTEPH) patients with pressure-overloaded right hearts, undergoing pulmonary thromboendarterectomy (n = 10) and from patients with normal right hearts operated by valve replacement or coronary bypass surgery (n = 9). The trabeculae were placed in an organ bath, continuously paced at 1 Hz. They were subjected to increasing concentrations of iloprost, treprostinil, epoprostenol, or MRE-269, followed by isoprenaline to elicit a reference inotropic response. The force of contraction was measured continuously. The expression of prostanoid receptors was explored through quantitative polymerase chain reaction (qPCR). Iloprost, treprostinil, epoprostenol, or MRE-269 did not alter force of contraction in any of the trabeculae. Isoprenaline showed a direct inotropic response in both trabeculae from the pressure-overloaded right atrium and from the normal right atrium. Control experiments on ventricular trabeculae from the pig failed to show an inotropic response to the prostacyclin mimetics. qPCR demonstrated varying expression of the different prostanoid receptors in the human atrium. In conclusion, prostacyclin mimetics did not increase the force of contraction of human atrial trabeculae from the normal or the pressure-overloaded right heart. These data suggest that prostacyclin mimetics have no direct inotropic effects in the human right atrium.

Central exogenous nitric oxide decreases cardiac sympathetic drive and improves baroreflex control of heart rate in ovine heart failure.

PubMed

Ramchandra, Rohit; Hood, Sally G; May, Clive N

2014-08-01

Heart failure (HF) is associated with increased cardiac and renal sympathetic drive, which are both independent predictors of poor prognosis. A candidate mechanism for the centrally mediated sympathoexcitation in HF is reduced synthesis of the inhibitory neuromodulator nitric oxide (NO), resulting from downregulation of neuronal NO synthase (nNOS). Therefore, we investigated the effects of increasing the levels of NO in the brain, or selectively in the paraventricular nucleus of the hypothalamus (PVN), on cardiac sympathetic nerve activity (CSNA) and baroreflex control of CSNA and heart rate in ovine pacing-induced HF. The resting level of CSNA was significantly higher in the HF than in the normal group, but the resting level of RSNA was unchanged. Intracerebroventricular infusion of the NO donor sodium nitroprusside (SNP; 500 μg · ml(-1)· h(-1)) in conscious normal sheep and sheep in HF inhibited CSNA and restored baroreflex control of heart rate, but there was no change in RSNA. Microinjection of SNP into the PVN did not cause a similar cardiac sympathoinhibition in either group, although the number of nNOS-positive cells was decreased in the PVN of sheep in HF. Reduction of endogenous NO with intracerebroventricular infusion of N(ω)-nitro-l-arginine methyl ester decreased CSNA in normal but not in HF sheep and caused no change in RSNA in either group. These findings indicate that endogenous NO in the brain provides tonic excitatory drive to increase resting CSNA in the normal state, but not in HF. In contrast, exogenously administered NO inhibited CSNA in both the normal and HF groups via an action on sites other than the PVN. Copyright © 2014 the American Physiological Society.

Fetal heart rate and fetal heart rate variability in Lipizzaner broodmares.

PubMed

Baska-Vincze, Boglárka; Baska, Ferenc; Szenci, Ottó

2015-03-01

Monitoring fetal heart rate (FHR) and fetal heart rate variability (FHRV) helps to understand and evaluate normal and pathological conditions in the foal. The aim of this study was to establish normal heart rate reference values for the ongoing equine pregnancy and to perform a heart rate variability (HRV) time-domain analysis in Lipizzaner mares. Seventeen middle- and late-term (days 121-333) pregnant Lipizzaner mares were examined using fetomaternal electrocardiography (ECG). The mean FHR (P = 0.004) and the standard deviation of FHR (P = 0.012) significantly decreased during the pregnancy. FHR ± SD values decreased from 115 ± 35 to 79 ± 9 bpm between months 5 and 11. Our data showed that HRV in the foal decreased as the pregnancy progressed, which is in contrast with the findings of earlier equine studies. The standard deviation of normal-normal intervals (SDNN) was higher (70 ± 25 to 166 ± 108 msec) than described previously. The root mean square of successive differences (RMSSD) decreased from 105 ± 69 to 77 ± 37 msec between the 5th and 11th month of gestation. Using telemetric ECG equipment, we could detect equine fetal heartbeat on day 121 for the first time. In addition, the large differences observed in the HR values of four mare-fetus pairs in four consecutive months support the assumption that there might be 'high-HR' and 'low-HR' fetuses in horses. It can be concluded that the analysis of FHR and FHRV is a promising tool for the assessment of fetal well-being but the applicability of these parameters in the clinical setting and in studs requires further investigation.

Cardiac support device (ASD) delivers bone marrow stem cells repetitively to epicardium has promising curative effects in advanced heart failure.

PubMed

Yue, Shizhong; Naveed, Muhammad; Gang, Wang; Chen, Dingding; Wang, Zhijie; Yu, Feng; Zhou, Xiaohui

2018-05-12

Ventricular restraint therapy is a non-transplant surgical option for the management of advanced heart failure (HF). To augment the therapeutic applications, it is hypothesized that ASD shows remarkable capabilities not only in delivering stem cells but also in dilated ventricles. Male SD rats were divided into four groups (n = 6): normal, HF, HF + ASD, and HF + ASD-BMSCs respectively. HF was developed by left anterior descending (LAD) coronary artery ligation in all groups except normal group. Post-infarcted electrocardiography (ECG) and brain natriuretic peptide (BNP) showed abnormal heart function in all model groups and HF + ASD-BMSCs group showed significant improvement as compared to other HF, HF + ASD groups on day 30. Masson's trichrome staining was used to study the histology, and a large blue fibrotic area has been observed in HF and HF + ASD groups and quantification of fibrosis was assessed. ASD-treated rats showed normal heart rhythm, demonstrated by smooth -ST and asymmetrical T-wave. The mechanical function of the heart such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and heart rate was brought to normal when treated with ASD-BMSCs. This effect was more prominent than that of ASD therapy alone. In comparison to HF group, the SD rats in HF + ASD-BMBCs group showed a significant decline in BNP levels. So ASD can deliver BMSCs to the cardiomyocytes successfully and broaden the therapeutic efficacy, in comparison to the restraint device alone. An effective methodology to manage the end-stage HF has been proved.

Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

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

He, Shu-Fang; Jin, Shi-Yun; Wu, Hao

Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct sizemore » and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.« less

Respiratory sinus arrhythmia stabilizes mean arterial blood pressure at high-frequency interval in healthy humans.

PubMed

Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne

2015-03-01

Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.

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.

Guide to Understanding Frontonasal Dysplasia

MedlinePlus

... although most people with FND are of normal intelligence. Heart Rare cases of frontonasal dysplasia may be ... prognosis m any people with FND have normal intelligence and can expect a normal lifespan. how can ...

Heart Rate and Electrocardiography Monitoring in Mice

PubMed Central

Ho, David; Zhao, Xin; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.

2011-01-01

The majority of current cardiovascular research involves studies in genetically engineered mouse models. The measurement of heart rate is central to understanding cardiovascular control under normal conditions, with altered autonomic tone, superimposed stress or disease states, both in wild type mice as well as those with altered genes. Electrocardiography (ECG) is the “gold standard” using either hard wire or telemetry transmission. In addition, heart rate is measured or monitored from the frequency of the arterial pressure pulse or cardiac contraction, or by pulse oximetry. For each of these techniques, discussions of materials and methods, as well as advantages and limitations are covered. However, only the direct ECG monitoring will determine not only the precise heart rates but also whether the cardiac rhythm is normal or not. PMID:21743842

Normotensive cardiomyopathy and malignant hypertension in phaeochromocytoma

PubMed Central

Shapiro, L. M.; Trethowan, N.; Singh, S. P.

1982-01-01

A patient with two different presentations of phaeochromocytoma is described. She initially presented with normal blood pressure and heart failure following a prolonged feverish prodrome. A provisional diagnosis of myocarditis or early congestive cardiomyopathy was made and she improved with digoxin and diuretics. Eighteen months later, after a period of normotension free from heart failure, she developed malignant hypertension with recurrence of heart failure. A phaeochromocytoma was surgically removed, with return to normal of blood pressure and cardiac status. It would seem that the initial presentation of the phaeochromocytoma was a catecholamine-induced myocarditis without hypertension and this resolved with the subsequent development of malignant hypertension. The possible mechanisms responsible for this are discussed and it is concluded that phaeochromocytoma should be considered in patients who have heart failure and persistent features of myocarditis. PMID:7100023

Effect of fluorocarbons on acetylcholinesterase activity and some counter measures

NASA Technical Reports Server (NTRS)

Young, W.; Parker, J. A.

1975-01-01

An isolated vagal sympathetic heart system has been successfully used for the study of the effect of fluorocarbons (FCs) on cardiac performance and in situ enzyme activity. Dichlorodifluoromethane sensitizes this preparation to sympathetic stimulation and to exogenous epinephrine challenge. Partial and complete A-V block and even cardiac arrest have been induced by epinephrine challenge in the FC sensitized heart. Potassium chloride alone restores the rhythmicity but not the normal contractility of the heart in such a situation. Addition of glucose will, however, completely restore the normal function of the heart which is sensitized by dichlorodifluoromethane. The ED 50 values of acetylcholinesterase activity which are used as a measure of relative effectiveness of fluorocarbons are compared with the maximum permissible concentration. Kinetic studies indicate that all the fluorocarbons tested so far are noncompetitive.

Cardiac voltage gated calcium channels and their regulation by β-adrenergic signaling.

PubMed

Kumari, Neema; Gaur, Himanshu; Bhargava, Anamika

2018-02-01

Voltage-gated calcium channels (VGCCs) are the predominant source of calcium influx in the heart leading to calcium-induced calcium release and ultimately excitation-contraction coupling. In the heart, VGCCs are modulated by the β-adrenergic signaling. Signaling through β-adrenergic receptors (βARs) and modulation of VGCCs by β-adrenergic signaling in the heart are critical signaling and changes to these have been significantly implicated in heart failure. However, data related to calcium channel dysfunction in heart failure is divergent and contradictory ranging from reduced function to no change in the calcium current. Many recent studies have highlighted the importance of functional and spatial microdomains in the heart and that may be the key to answer several puzzling questions. In this review, we have briefly discussed the types of VGCCs found in heart tissues, their structure, and significance in the normal and pathological condition of the heart. More importantly, we have reviewed the modulation of VGCCs by βARs in normal and pathological conditions incorporating functional and structural aspects. There are different types of βARs, each having their own significance in the functioning of the heart. Finally, we emphasize the importance of location of proteins as it relates to their function and modulation by co-signaling molecules. Its implication on the studies of heart failure is speculated. Copyright © 2017 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.

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.