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Sample records for 64-slice cardiac computed

  1. Visual claudicatio: diagnosis with 64-slice computed tomography.

    PubMed

    Cademartiri, Filippo; Maffei, Erica; Palumbo, Alessandro; Mollet, Nico R; van der Lugt, Aad; Crisi, Girolamo

    2007-06-01

    We present a case of a 78-year-old male referred presented to our institution with amaurosis fugax after walking 20 steps ("visual claudicatio"). Duplex ultrasound was not able to visualize the carotid arteries. Multislice computed tomography (Sensation 64 Cardiac, Siemens, Germany) of the cerebro-vascular circulation was performed from its origin at the level of the aortic arch to the circle of Willis. The investigation demonstrated a complete occlusion of both common carotid arteries at their origin and a severe origo stenosis of both vertebral arteries. An important collateral circulation of the vertebral arteries through the minor vessels of the neck was also displayed. Both comunicans posterior arteries were small but patent. The intra-cranial arteries were patent. Multislice CT of the cerebro-vascular circulation is an optimal tool for a comprehensive evaluation when duplex ultrasound fails.

  2. 64-Slice Computed Tomographic Angiography for the Diagnosis of Intermediate Risk Coronary Artery Disease

    PubMed Central

    2010-01-01

    Executive Summary In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities. After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website). The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html Single Photon Emission Computed Tomography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Stress Echocardiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Stress Echocardiography with Contrast for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis 64-Slice Computed Tomographic Angiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Cardiac

  3. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    PubMed

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (<1 years old) with CHD undergoing 128-slice CT prospective ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  4. 64 slice-coronary computed tomography sensitivity and specificity in the evaluation of coronary artery bypass graft stenosis: A meta-analysis.

    PubMed

    Barbero, Umberto; Iannaccone, Mario; d'Ascenzo, Fabrizio; Barbero, Cristina; Mohamed, Abdirashid; Annone, Umberto; Benedetto, Sara; Celentani, Dario; Gagliardi, Marco; Moretti, Claudio; Gaita, Fiorenzo

    2016-08-01

    A non-invasive approach to define grafts patency and stenosis in the follow-up of coronary artery bypass graft (CABG) patients may be an interesting alternative to coronary angiography. 64-slice-coronary computed tomography is nowadays a diffused non-invasive method that permits an accurate evaluation of coronary stenosis, due to a high temporal and spatial resolution. However, its sensitivity and specificity in CABG evaluation has to be clearly defined, since published studies used different protocols and scanners. We collected all studies investigating patients with stable symptoms and previous CABG and reporting the comparison between diagnostic performances of invasive coronary angiography and 64-slice-coronary computed tomography. As a result, sensitivity and specificity of 64-slice-coronary computed tomography for CABG occlusion were 0.99 (95% CI 0.97-1.00) and 0.99 (95% CI: 0.99-1.00) with an area under the curve (AUC) of 0.99. 64-slice-coronary computed tomography sensitivity and specificity for the presence of any CABG stenosis >50% were 0.98 (95% CI: 0.97-0.99) and 0.98 (95% CI: 0.96-0.98), while AUC was 0.99. At meta-regression, neither the age nor the time from graft implantation had effect on sensitivity and specificity of 64-slice-coronary computed tomography detection of significant CABG stenosis or occlusion. In conclusion 64-slice-coronary computed tomography confirmed its high sensitivity and specificity in CABG stenosis or occlusion evaluation.

  5. Beam hardening artifacts by dental implants: Comparison of cone-beam and 64-slice computed tomography scanners

    PubMed Central

    Esmaeili, Farzad; Johari, Masume; Haddadi, Pezhman

    2013-01-01

    Background: Cone beam computed tomography (CBCT) is an alternative to a computed tomography (CT) scan, which is appropriate for a wide range of craniomaxillofacial indications. The long-term use of metallic materials in dentistry means that artifacts caused by metallic restorations in the oral cavity should be taken into account when utilizing CBCT and CT scanners. The aim of this study was to quantitatively compare the beam hardening artifacts produced by dental implants between CBCT and a 64-Slice CT scanner. Materials and Methods: In this descriptive study, an implant drilling model similar to the human mandible was used in the present study. The implants (Dentis) were placed in the canine, premolar and molar areas. Three series of scans were provided from the implant areas using Somatom Sensation 64-slice and NewTom VGi (CBCT) CT scanners. Identical images were evaluated by three radiologists. The artifacts in each image were determined based on pre-determined criteria. Kruskal-Wallis test was used to compare mean values; Mann-Whitney U test was used for two-by-two comparisons when there was a statistical significance (P < 0.05). Results: The images of the two scanners had similar resolutions in axial sections (P = 0.299). In coronal sections, there were significant differences in the resolutions of the images produced by the two scanners (P < 0.001), with a higher resolution in the images produced by NewTom VGi scanner. On the whole, there were significant differences between the resolutions of the images produced by the two CT scanners (P < 0.001), with higher resolution in the images produced by NewTom VGi scanner in comparison to those of Somatom Sensation. Conclusion: Given the high quality of the images produced by NewTom VGi and the lower costs in comparison to CT, the use of the images of this scanner in dental procedures is recommended, especially in patients with extensive restorations, multiple prostheses and previous implants. PMID:24019808

  6. 64-Slice spiral computed tomography and three-dimensional reconstruction in the diagnosis of cystic pancreatic tumors

    PubMed Central

    WEN, ZHAOXIA; YAO, FENGQING; WANG, YUXING

    2016-01-01

    The present study aimed to describe the characteristics of cystic pancreatic tumors using computed tomography (CT) and to evaluate the diagnostic accuracy (DA) of post-imaging three-dimensional (3D) reconstruction. Clinical and imaging data, including multi-slice spiral CT scans, enhanced scans and multi-faceted reconstruction, from 30 patients with pathologically confirmed cystic pancreatic tumors diagnosed at the Linyi People's Hospital between August 2008 and June 2014 were retrospectively analyzed. Following the injection of Ultravist® 300 contrast agent, arterial, portal venous and parenchymal phase scans were obtained at 28, 60 and 150 sec, respectively, and 3D reconstructions of the CT images were generated. The average age of the patients was 38.4 years (range, 16–77 years), and the cohort included 5 males and 25 females (ratio, 1:5). The patients included 8 cases of mucinous cystadenoma (DA), 80%]; 9 cases of cystadenocarcinoma (DA, 84%); 6 cases of serous cystadenoma (DA, 100%); 3 cases of solid pseudopapillary tumor (DA, 100%); and 4 cases of intraductal papillary mucinous neoplasm (DA, 100%). 3D reconstructions of CT images were generated and, in the 4 cases of intraductal papillary mucinous neoplasm, the tumor was connected to the main pancreatic duct and multiple mural nodules were detected in one of these cases. The DA of the 3D-reconstructed images of cystic pancreatic tumors was 89.3%. The 64-slice spiral CT and 3D-reconstructed CT images facilitated the visualization of cystic pancreatic tumor characteristics, in particular the connections between the tumor and the main pancreatic duct. In conclusion, the 3D reconstruction of multi-slice CT data may provide an important source of information for the surgical team, in combination with the available clinical data. PMID:27073473

  7. [Examination of the effectiveness of heart rate control using intravenous β-blocker in 64-slice coronary computed tomography angiography].

    PubMed

    Yamaguchi, Takayoshi; Takahashi, Daichi; Nakagawa, Shingo; Morita, Mari; Noda, Rie; Nakamura, Yoko; Igarashi, Keiichi

    2012-01-01

    The purpose of this study is to clarify the effectiveness of the use of β-blocker in coronary computed tomography angiography (CCTA). In 1783 patients, heart rate was controlled by propranolol injection to patients with heart rates of 61 bpm or more. As a result, the scan heart rate (58.8±6.5 bpm) decreased significantly compared with the initial heart rate (72.7±9.4 bpm). Prospective gating method was used by 61.9% including 64.3% of the intravenous β-blocker injection group. Moreover, daily use of oral β-blocker had influence on reduction of the scan heart rate (daily use group: 60.1±6.5 bpm vs. unuse group: 58.5±6.3 bpm p<0.01). When we evaluated the image quality of CCTA by the score, the improvement of the score was obviously admitted by 65 bpm or less of the scan heart rate. The ratio of scan heart rate that was controlled by 65 bpm or less was decreased in the initial heart rate groups that were 81 bpm or more. The incidence of adverse reactions by the propranolol injection was few, and these instances only involved slight symptoms. Therefore, heart rate control with the use of β-blocker is useful for the image quality improvement of CCTA. This form of treatment can be safely enforced.

  8. Non-invasive Detection of Aortic and Coronary Atherosclerosis in Homozygous Familial Hypercholesterolemia by 64 Slice Multi-detector Row Computed Tomography Angiography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector-row ...

  9. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  10. Preoperative quantification of aortic valve stenosis: comparison of 64-slice computed tomography with transesophageal and transthoracic echocardiography and size of implanted prosthesis.

    PubMed

    Mizia-Stec, Katarzyna; Pysz, Piotr; Jasiński, Marek; Adamczyk, Tomasz; Drzewiecka-Gerber, Agnieszka; Chmiel, Artur; Krejca, Michał; Bochenek, Andrzej; Woś, Stanisław; Sosnowski, Maciej; Gąsior, Zbigniew; Trusz-Gluza, Maria; Tendera, Michał

    2012-02-01

    Precise measurements of aortic complex diameters are essential for preoperative examinations of patients with aortic stenosis (AS) scheduled for aortic valve (AV) replacement. We aimed to prospectively compare the accuracy of transthoracic echocardiography (TTE), transoesophageal echocardiography (TEE) and multi-slice computed tomography (MSCT) measurements of the AV complex and to analyze the role of the multi-modality aortic annulus diameter (AAd) assessment in the selection of the optimal prosthesis to be implanted in patients surgically treated for degenerative AS. 20 patients (F/M: 3/17; age: 69 ± 6.5 years) with severe degenerative AS were enrolled into the study. TTE, TEE and MSCT including AV calcium score (AVCS) assessment were performed in all patients. The values of AAd obtained in the long AV complex axis (TTE, TEE, MSCT) and in multiplanar perpendicular imaging (MSCT) were compared to the size of implanted prosthesis. The mean AAd was 24 ± 3.6 mm using TTE, 26 ± 4.2 mm using TEE, and 26.9 ± 3.2 in MSCT (P = 0.04 vs. TTE). The mean diameter of the left ventricle out-flow tract in TTE (19.9 ± 2.7 mm) and TEE (19.5 ± 2.7 mm) were smaller than in MSCT (24.9 ± 3.3 mm, P < 0.001 for both). The mean size of implanted prosthesis (22.2 ± 2.3 mm) was significantly smaller than the mean AAd measured by TTE (P = 0.0039), TEE (P = 0.0004), and MSCT (P < 0.0001). The implanted prosthesis size correlated significantly to the AAd: r = 0.603, P = 0.005 for TTE, r = 0.592, P = 0.006 for TEE, and r = 0.791, P < 0.001 for MSCT. Obesity and extensive valve calcification (AV calcium score ≥ 3177Ag.U.) were identified as potent factors that caused a deterioration of both TTE and MSCT performance. The accuracy of AAd measurements in TEE was only limited by AV calcification. In multivariate regression analysis the mean value of the minimum and maximum AAd obtained in MSCT-multiplanar perpendicular imaging was an

  11. Hemodialysis fistula occlusion: demonstration with 64-slice CT angiography.

    PubMed

    Neyman, Edward G; Johnson, Pamela T; Fishman, Elliot K

    2006-01-01

    The speed and resolution of 64-slice CT have resulted in new applications for CT angiography (CTA) owing to rapid data acquisition during the arterial phase, improved visualization of small vessels, and lengthened anatomic coverage. Extremity CT angiography is one such region. This case report shows the utility of multislice CTA for the evaluation of hemodialysis graft dysfunction.

  12. The value of 64-slice spiral CT perfusion imaging in the treatment of liver cancer with argon-helium cryoablation

    PubMed Central

    Lv, Yinggang; Jin, Yurong; Yan, Qiaohuan; Yuan, Dingling; Wang, Yanling; Li, Xianping; Shen, Yanfeng

    2016-01-01

    We analyzed the effectiveness of using 64-slice spiral computed tomography (CT) and perfusion imaging to guide argon-helium cryoablation treatment of liver cancer. In total, 60 cases of advanced hepatocellular carcinoma before surgery treated with argon-helium cryoablation were inlcuded in the present study. Retrospective summary of the 60 cases of metaphase and advanced liver cancer were used as the control group. The control group were treated using cryoablation with argon-helium knife. We used enhanced scanning with 64-slice spiral CT to define the extent of their lesions and prepared a plan of percutaneous cryoablation for the treatment. Intraoperatively, we used the dynamics of CT perfusion imaging to observe the frozen ablation range and decreased the rate of complications. After surgery, the patients were followed-up regularly by 64-slice CT. We used conventional X-ray, CT and magnetic resonance imaging (MRI) for pre-operative lateralization. Intraoperative X-ray or ultrasound guidance and follow-up with CT or MTI were added to determine the clinical effectiveness and prognosis. The results showed that the total effective rate was improved significantly and incidence rate of overall complications decreased markedly in the observation group. Following treatment, AFP decreased significantly while the total freezing area and time were reduced significantly. The median survival time was increased significantly in the observation group. The numeric values of hepatic arterial perfusion, portal vein perfusion and hepatic arterial perfusion index were all markedly lowered after treatment. Differences were statistically significant (P<0.05). In conclusion, the use of 64-slice spiral CT perfusion imaging may considerably improve the effects of liver cancer treatment using the argon-helium cryoablation. It extended the survival time and reduced complications. PMID:28105165

  13. Controlled Cardiac Computed Tomography

    PubMed Central

    Wang, Chenglin; Liu, Ying; Wang, Ge

    2006-01-01

    Cardiac computed tomography (CT) has been a hot topic for years because of the clinical importance of cardiac diseases and the rapid evolution of CT systems. In this paper, we propose a novel strategy for controlled cardiac CT that may effectively reduce image artifacts due to cardiac and respiratory motions. Our approach is radically different from existing ones and is based on controlling the X-ray source rotation velocity and powering status in reference to the cardiac motion. We theoretically show that by such a control-based intervention the data acquisition process can be optimized for cardiac CT in the cases of periodic and quasiperiodic cardiac motions. Specifically, we formulate the corresponding coordination/control schemes for either exact or approximate matches between the ideal and actual source positions, and report representative simulation results that support our analytic findings. PMID:23165017

  14. Dosimetric and image quality assessment of different acquisition protocols of a novel 64-slice CT scanner

    NASA Astrophysics Data System (ADS)

    Vite, Cristina; Mangini, Monica; Strocchi, Sabina; Novario, Raffaele; Tanzi, Fabio; Carrafiello, Gianpaolo; Conte, Leopoldo; Fugazzola, Carlo

    2006-03-01

    Dose and image quality assessment in computed tomography (CT) are almost affected by the vast variety of CT scanners (axial CT, spiral CT, low-multislice CT (2-16), high-multislice CT (32-64)) and imaging protocols in use. Very poor information is at the moment available on 64 slices CT scanners. Aim of this work is to assess image quality related to patient dose indexes and to investigate the achievable dose reduction for a commercially available 64 slices CT scanner. CT dose indexes (weighted computed tomography dose index, CTDI w and Dose Length Product, DLP) were measured with a standard CT phantom for the main protocols in use (head, chest, abdomen and pelvis) and compared with the values displayed by the scanner itself. The differences were always below 7%. All the indexes were below the Diagnostic Reference Levels defined by the European Council Directive 97/42. Effective doses were measured for each protocol with thermoluminescent dosimeters inserted in an anthropomorphic Alderson Rando phantom and compared with the same values computed by the ImPACT CT Patient Dosimetry Calculator software code and corrected by a factor taking in account the number of slices (from 16 to 64). The differences were always below 25%. The effective doses range from 1.5 mSv (head) to 21.8 mSv (abdomen). The dose reduction system of the scanner was assessed comparing the effective dose measured for a standard phantom-man (a cylinder phantom, 32 cm in diameter) to the mean dose evaluated on 46 patients. The standard phantom was considered as no dose reduction reference. The dose reduction factor range from 16% to 78% (mean of 46%) for all protocols, from 29% to 78% (mean of 55%) for chest protocol, from 16% to 76% (mean of 42%) for abdomen protocol. The possibility of a further dose reduction was investigated measuring image quality (spatial resolution, contrast and noise) as a function of CTDI w. This curve shows a quite flat trend decreasing the dose approximately to 90% and a

  15. Evaluation of temporal windows for coronary artery bypass graft imaging with 64-slice CT.

    PubMed

    Desbiolles, Lotus; Leschka, Sebastian; Plass, André; Scheffel, Hans; Husmann, Lars; Gaemperli, Oliver; Garzoli, Elisabeth; Marincek, Borut; Kaufmann, Philipp A; Alkadhi, Hatem

    2007-11-01

    Temporal windows providing the best image quality of different segments and types of coronary artery bypass grafts (CABGs) with 64-slice computed tomography (CT) were evaluated in an experimental set-up. Sixty-four-slice CT with a rotation time of 330 ms was performed in 25 patients (four female; mean age 59.9 years). A total of 84 CABGs (62 individual and 22 sequential grafts) were evaluated, including 28 internal mammary artery (33.3%), one radial artery with sequential grafting (2.4%), and 54 saphenous vein grafts (64.3%). Ten data sets were reconstructed in 10% increments of the RR-interval. Each graft was separated into segments (proximal and distal anastomosis, and body), and CABG types were grouped according to target arteries. Two readers independently assessed image quality of each CABG segment in each temporal window. Diagnostic image quality was found with good inter-observer agreement (kappa=0.62) in 98.5% (202/205) of all graft segments. Image quality was significantly better for saphenous vein grafts versus arterial grafts (P<0.001) and for distal anastomosis to the right coronary compared with other target coronary arteries (P<0.05). Overall, best image quality was found at 60%. Image quality of proximal segments did not significantly vary with the temporal window, whereas for all other segments image quality was significantly better at 60% compared with other temporal windows (P<0.05). Sixty-four-slice CT provides best image quality of various segments and types of CABG at 60% of the RR-interval.

  16. A new approach to the assessment of lumen visibility of coronary artery stent at various heart rates using 64-slice MDCT

    PubMed Central

    Groen, J. M.; van Ooijen, P. M. A.; Oudkerk, M.

    2007-01-01

    Coronary artery stent lumen visibility was assessed as a function of cardiac movement and temporal resolution with an automated objective method using an anthropomorphic moving heart phantom. Nine different coronary stents filled with contrast fluid and surrounded by fat were scanned using 64-slice multi-detector computed tomography (MDCT) at 50–100 beats/min with the moving heart phantom. Image quality was assessed by measuring in-stent CT attenuation and by a dedicated tool in the longitudinal and axial plane. Images were scored by CT attenuation and lumen visibility and compared with theoretical scoring to analyse the effect of multi-segment reconstruction (MSR). An average increase in CT attenuation of 144 ± 59 HU and average diminished lumen visibility of 29 ± 12% was observed at higher heart rates in both planes. A negative correlation between image quality and heart rate was non-significant for the majority of measurements (P > 0.06). No improvement of image quality was observed in using MSR. In conclusion, in-stent CT attenuation increases and lumen visibility decreases at increasing heart rate. Results obtained with the automated tool show similar behaviour compared with attenuation measurements. Cardiac movement during data acquisition causes approximately twice as much blurring compared with the influence of temporal resolution on image quality. Electronic supplementary material The online version of this article (doi:10.1007/s00330-007-0568-8) contains supplementary material, which is available to authorized users. PMID:17429648

  17. Carotid stenosis evaluation by 64-slice CTA: comparison of NASCET, ECST and CC grading methods.

    PubMed

    Kılıçkap, Gülsüm; Ergun, Elif; Başbay, Elif; Koşar, Pınar; Kosar, Uğur

    2012-06-01

    Purpose is to evaluate the intraobserver and interobserver variability of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST) and Common Carotid (CC) methods, which are used to measure the degree of ICA stenosis, using 64-slice CT angiography and to compare the measurements made by these three methods. 88 cases (111 carotid arteries) were included in the study. Carotid CTA was performed by a 64 slice scanner (Toshiba, Aqullion 64).Two radiologists measured the degree of carotid stenosis by using NASCET, ECST and CC methods. Intraobserver and interobserver variability of each method was determined by intraclass correlation coefficient (ICC), Bland-Altman plots and kappa and linear weighted kappa statistics. The relation between the measurements was assessed by correlation coefficient (with linear and quadratic methods). Correlation coefficients showed that there is linear correlation between the measurements made by the three methods. The degree of stenosis measured with the NASCET method had the lowest value, while the corresponding values measured with the ECST and CC methods were close to each other. ICC and Bland-Altman plots showed high intra and inter observer agreement for NASCET, ECST and CC methods whereas kappa statistics showed moderate to substantial agreement. CC method had slightly higher agreement when compared with the other two methods. Intra and interobserver agreement is high for NASCET, ECST and CC methods however CC method has a slightly higher reproducibility. There is linear correlation between the measurements made by the three methods.

  18. Integrative computed tomographic imaging of cardiac structure, function, perfusion, and viability.

    PubMed

    Thilo, Christian; Hanley, Michael; Bastarrika, Gorka; Ruzsics, Balazs; Schoepf, U Joseph

    2010-01-01

    Recent advances in multidetector-row computed tomography (MDCT) technology have created new opportunities in cardiac imaging and provided new insights into a variety of disease states. Use of 64-slice coronary computed tomography angiography has been validated for the evaluation of clinically relevant coronary artery stenosis with high negative predictive values for ruling out significant obstructive disease. This technology has also advanced the care of patients with acute chest pain by simultaneous assessment of acute coronary syndrome, pulmonary embolism, and acute aortic syndrome ("triple rule out"). Although MDCT has been instrumental in the advancement of cardiac imaging, there are still limitations in patients with high or irregular heart rates. Newer MDCT scanner generations hold promise to improve some of these limitations for noninvasive cardiac imaging. The evaluation of coronary artery stenosis remains the primary clinical indication for cardiac computed tomography angiography. However, the use of MDCT for simultaneous assessment of coronary artery stenosis, atherosclerotic plaque formation, ventricular function, myocardial perfusion, and viability with a single modality is under intense investigation. Recent technical developments hold promise for accomplishing this goal and establishing MDCT as a comprehensive stand-alone test for integrative imaging of coronary heart disease.

  19. Acute chest pain in emergency room. Preliminary findings with 40-64-slice CT ECG-gated of the whole chest.

    PubMed

    Coche, E

    2007-01-01

    ECG-gated MDCT of the entire chest represents the latest technical advance in the diagnostic work-up of atypical chest pain. The authors report their preliminary experience with the use of 40 and 64-slice CT in the emergency room and recommend to study only patients with moderate likelihood of coronary artery disease. ECG-gated MDCT of the entire chest will be preferentially performed on 64-slice MDCT rather than 40-slice MDCT because it enable to reduce the scan time (18 seconds versus 28 seconds acquisition time), the volume of contrast medium (82 mL + 15 mL versus 97 mL + 15 mL of highly concentrated contrast agent for a patient of 70 kgs) and radiation exposure (17 mSv versus 19 mSv). Approximately 1500 to 2000 of images are produced and need to be analysed on a dedicated workstation by a radiologist expert in cardiac and thoracic disorders. At the present time, only a few studies exist in the literature showing some promising results but further large clinical studies are needed before to implement such sophisticated protocol in emergency room.

  20. Diagnostic Capabilities of 64 Slice CT Coronography Compared to Classic in Coronary Disease Detection

    PubMed Central

    Sehovic, Sanja

    2013-01-01

    Introduction: Cardiovascular disease, among which the most common is coronary disease of the hearth are the main cause of death at middle aged persons in the majority of European countries. Percent of cardiovascular disease in overall mortality among our population is even more than 50%. Up to 55 years of live myocardial infarction is by 5-6 times more common among men, and up to age of 75 years that difference decreases to 2.5 times. Goal: The goal of this study is to determine the diagnostic value of 64 slices computerized tomography in detection of coronary disease compared to classic, invasive coronography. Material and methods: Study included 50 patients, of both genders, at average age of 60 years. Patients underwent CT coronography as well as classic coronography. Results: Our research prove that the sensitivity of MSCT coronography 92% with positive predictive value of 86%. Mayor difference was in the analysis of CX artery in the evaluation of significant and non-significant stenosis in application of these two methods. During the analysis of LAD and RCA artery there was no statistically significant difference in findings of these two methods. Conclusion: CT coronography is non-invasive, comfortable and reliable method in coronary disease diagnostics. Thanks to its high sensitivity and PPV it enables reliable exclusion of coronary disease and takes significant place in a cardiovascular diseases diagnostic algorithm. PMID:24167394

  1. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution: A cardiac phantom study

    SciTech Connect

    Greuter, M. J. W.; Groen, J. M.; Nicolai, L. J.; Dijkstra, H.; Oudkerk, M.

    2009-11-15

    Purpose: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative method which corrects for the influences of these parameters using a linear moving cardiac phantom. Methods: On a robotic arm with artificial arteries with four calcifications of increasing density, a linear movement was applied between 0 and 120 mm/s (step of 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT, and EBT using a standard acquisition protocol. The average Agatston, volume, and mass scores were determined for each velocity, calcification, and scanner. Susceptibility to motion was quantified using a cardiac motion susceptibility (CMS) index. Resemblance to EBT and physical volume and mass was quantified using a {Delta} index. Results: Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The calcium score showed a linear dependency on motion from which a correction factor could be derived. This correction factor showed a linear dependency on the mean calcification density with a good fit for all three scoring methods and all three scanners (0.73{<=}R{sup 2}{<=}0.95). The slope and offset of this correction factor showed a linear dependency on temporal resolution with a good fit for all three scoring methods and all three scanners (0.83{<=}R{sup 2}{<=}0.98). CMS was minimal for EBT and increasing values were observed for DSCT and highest values for 64-slice MDCT. CMS was minimal for mass score and increasing values were observed for volume score and highest values for Agatston score. For all densities and scoring methods DSCT showed on average the closest resemblance to EBT calcium scores. When using the correction factor, CMS index decreased on average by

  2. Prospectively gated cardiac computed tomography.

    PubMed

    Moore, S C; Judy, P F; Garnic, J D; Kambic, G X; Bonk, F; Cochran, G; Margosian, P; McCroskey, W; Foote, F

    1983-01-01

    A fourth-generation scanner has been modified to perform prospectively gated cardiac computed tomography (CT). A computer program monitors the electrocardiogram (ECG) and predicts when to initiate the next scan in a gated series in order to acquire all projection data for a desired phase of the heart cycle. The system has been tested with dogs and has produced cross-sectional images of all phases of the cardiac cycle. Eight to ten scans per series were sufficient to obtain reproducible images of each transverse section in the end-diastolic and end-systolic phases. The radiation dose to the skin was approximately 1.4 cGy per scan. The prospectively gated system is more than twice as efficient as a retrospectively gated system in obtaining complete angular projection data for a 10% heart cycle window. A temporal smoothing technique to suppress reconstruction artifacts due to sorting inconsistent projection data was developed and evaluated. Image noise was reduced by averaging together any overlapping projection data. Prospectively gated cardiac CT has also been used to demonstrate that the error in attenuation measured with a single nongated CT scan through the heart can be as large as 50-60 CT numbers outside the heart in the lung field.

  3. Applications of Computational Modeling in Cardiac Surgery

    PubMed Central

    Lee, Lik Chuan; Genet, Martin; Dang, Alan B.; Ge, Liang; Guccione, Julius M.; Ratcliffe, Mark B.

    2014-01-01

    Although computational modeling is common in many areas of science and engineering, only recently have advances in experimental techniques and medical imaging allowed this tool to be applied in cardiac surgery. Despite its infancy in cardiac surgery, computational modeling has been useful in calculating the effects of clinical devices and surgical procedures. In this review, we present several examples that demonstrate the capabilities of computational cardiac modeling in cardiac surgery. Specifically, we demonstrate its ability to simulate surgery, predict myofiber stress and pump function, and quantify changes to regional myocardial material properties. In addition, issues that would need to be resolved in order for computational modeling to play a greater role in cardiac surgery are discussed. PMID:24708036

  4. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    NASA Astrophysics Data System (ADS)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  5. Integrated assessment of coronary anatomy and myocardial perfusion using a retractable SPECT camera combined with 64-slice CT: initial experience.

    PubMed

    Thilo, Christian; Schoepf, U Joseph; Gordon, Leonie; Chiaramida, Salvatore; Serguson, Jill; Costello, Philip

    2009-04-01

    We evaluated a prototype SPECT system integrated with multidetector row CT (MDCT) for obtaining complementary information on coronary anatomy and hemodynamic lesion significance. Twenty-five consecutive patients with known or suspected coronary artery disease (CAD) underwent routine SPECT myocardial perfusion imaging (MPI). All patients also underwent repeat MPI with a mobile SPECT unit which could be attached to a 64-slice MDCT system. Coronary CT angiography (cCTA) was performed without repositioning the patient. Investigational MPI was compared with routine MPI for detection of myocardial perfusion defects (PD). Two observers diagnosed presence or absence of CAD based on MPI alone, cCTA alone, and based on combined MPI and cCTA with fused image display. In 22/24 patients investigative MPI corresponded with routine MPI (r = 0.80). Stenosis >or= 50% at cCTA was detected in 6/24 patients. Six out of 24 patients had PD at regular MPI. Three of these six patients had no significant stenosis at cCTA. Three out of 19 patients with normal MPI studies had significant stenosis at cCTA. Our initial experience indicates that the integration of SPECT MPI with cCTA is technically feasible and enables the comprehensive evaluation of coronary artery anatomy and myocardial perfusion with a single instrumental setup.

  6. The 'mill-wheel' murmur and computed tomography of intracardiac air emboli.

    PubMed

    Rubal, Bernard J; Leon, Alisa; Meyers, Belinda L; Bell, Christopher M

    2009-05-01

    The 'water-wheel' or 'mill-wheel' murmur is classically associated with large intracardiac air emboli and described as a "characteristic splashing auscultatory sound due to the presence of gas in the cardiac chambers." We used 64-slice computed tomography (slice thickness, 0.5 mm; revolution time, 400 msec) and 3D fly-through software imagery to capture previously unreported intracardiac air-blood interface dynamics associated with this murmur and ineffective right ventricular contraction in a porcine model.

  7. Body physique and heart rate variability determine the occurrence of stair-step artefacts in 64-slice CT coronary angiography with prospective ECG-triggering.

    PubMed

    Husmann, Lars; Herzog, Bernhard A; Burkhard, Nina; Tatsugami, Fuminari; Valenta, Ines; Gaemperli, Oliver; Wyss, Christophe A; Landmesser, Ulf; Kaufmann, Philipp A

    2009-07-01

    The purpose of this study was to describe and characterize the frequency and extent of stair-step artefacts in computed tomography coronary angiography (CTCA) with prospective electrocardiogram (ECG)-triggering and to identify their determinants. One hundred and forty three consecutive patients (55 women, mean age 57 +/- 13 years) underwent 64-slice CTCA using prospective ECG-triggering. Occurrence of stair-step artefacts in CTCA of the thoracic wall and the coronary arteries was determined and maximum offset was measured. If stair-step artefacts occurred in both cases, a difference between thoracic wall and coronary artery offset of 0.6 mm or greater was attributed to additional motion of the heart. Mean effective radiation dose was 2.1 +/- 0.7 mSv (range 1.0-3.5 mSv). Eighty-nine patients (62%) had stair-step artefacts in CTCA of the coronary arteries (mean offset of 1.7 +/- 1.1 mm), while only 77 patients had thoracic wall stair-step artefacts (mean offset of 1.0 +/- 0.3 mm; significantly different, P < 0.001). Stair-step artefacts in CTCA of the thoracic wall were determined by BMI and weight (P < 0.01), while artefacts in CTCA of the coronary arteries were associated with heart rate variability (P < 0.05). Stair-step artefacts in CTCA with prospective ECG-triggering are determined by (a) motion of the entire patient during table travel, particularly in large patients and (b) by motion of the heart, particularly when heart rates are variable.

  8. Computing effective dose in cardiac CT

    NASA Astrophysics Data System (ADS)

    Huda, Walter; Tipnis, Sameer; Sterzik, Alexander; Schoepf, U. Joseph

    2010-07-01

    We present a method of estimating effective doses in cardiac CT that accounts for selected techniques (kV mAs-1), anatomical location of the scan and patient size. A CT dosimetry spreadsheet (ImPACT CT Patient Dosimetry Calculator) was used to estimate effective doses (E) using ICRP 103 weighting factors for a 70 kg patient undergoing cardiac CT examinations. Using dose length product (DLP) for the same scans, we obtained values of E/DLP for three CT scanners used in cardiac imaging from two vendors. E/DLP ratios were obtained as a function of the anatomical location in the chest and for x-ray tube voltages ranging from 80 to 140 kV. We also computed the ratio of the average absorbed dose in a water cylinder modeling a patient weighing W kg to the corresponding average absorbed dose in a water cylinder equivalent to a 70 kg patient. The average E/DLP for a 16 cm cardiac heart CT scan was 26 µSv (mGy cm)-1, which is about 70% higher than the current E/DLP values used for chest CT scans (i.e. 14-17 µSv (mGy cm)-1). Our cardiac E/DLP ratios are higher because the cardiac region is ~30% more radiosensitive than the chest, and use of the ICRP 103 tissue weighting factors increases cardiac CT effective doses by ~30%. Increasing the x-ray tube voltage from 80 to 140 kV increases the E/DLP conversion factor for cardiac CT by 17%. For the same incident radiation at 120 kV, doses in 45 kg adults were ~22% higher than those in 70 kg adults, whereas doses in 120 kg adults were ~28% lower. Accurate estimates of the patient effective dose in cardiac CT should use ICRP 103 tissue weighting factors, and account for a choice of scan techniques (kV mAs-1), exposed scan region, as well as patient size.

  9. Experimental assessment of the influence of beam hardening filters on image quality and patient dose in volumetric 64-slice X-ray CT scanners.

    PubMed

    Ay, Mohammad Reza; Mehranian, Abolfazl; Maleki, Asghar; Ghadiri, Hossien; Ghafarian, Pardis; Zaidi, Habib

    2013-05-01

    Beam hardening filters have long been employed in X-ray Computed Tomography (CT) to preferentially absorb soft and low-energy X-rays having no or little contribution to image formation, thus allowing the reduction of patient dose and beam hardening artefacts. In this work, we studied the influence of additional copper (Cu) and aluminium (Al) flat filters on patient dose and image quality and seek an optimum filter thickness for the GE LightSpeed VCT 64-slice CT scanner using experimental phantom measurements. Different thicknesses of Cu and Al filters (0.5-1.6mm Cu, 0.5-4mm Al) were installed on the scanner's collimator. A planar phantom consisting of 13 slabs of Cu having different thicknesses was designed and scanned to assess the impact of beam filtration on contrast in the intensity domain (CT detector's output). To assess image contrast and image noise, a cylindrical phantom consisting of a polyethylene cylinder having 16 holes filled with different concentrations of K2HPO4 solution mimicking different tissue types was used. The GE performance and the standard head CT dose index (CTDI) phantoms were also used to assess image resolution characterized by the modulation transfer function (MTF) and patient dose defined by the weighted CTDI. A 100mm pencil ionization chamber was used for CTDI measurement. Finally, an optimum filter thickness was determined from an objective figure of merit (FOM) metric. The results show that the contrast is somewhat compromised with filter thickness in both the planar and cylindrical phantoms. The contrast of the K2HPO4 solutions in the cylindrical phantom was degraded by up to 10% for a 0.68mm Cu filter and 6% for a 4.14mm Al filter. It was shown that additional filters increase image noise which impaired the detectability of low density K2HPO4 solutions. It was found that with a 0.48mm Cu filter the 50% MTF value is shifted by about 0.77lp/cm compared to the case where the filter is not used. An added Cu filter with approximately

  10. [Cardiac computed tomography: new applications of an evolving technique].

    PubMed

    Martín, María; Corros, Cecilia; Calvo, Juan; Mesa, Alicia; García-Campos, Ana; Rodríguez, María Luisa; Barreiro, Manuel; Rozado, José; Colunga, Santiago; de la Hera, Jesús M; Morís, César; Luyando, Luis H

    2015-01-01

    During the last years we have witnessed an increasing development of imaging techniques applied in Cardiology. Among them, cardiac computed tomography is an emerging and evolving technique. With the current possibility of very low radiation studies, the applications have expanded and go further coronariography In the present article we review the technical developments of cardiac computed tomography and its new applications.

  11. Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

    PubMed Central

    Matsuura, Noriaki; Yamamoto, Hideya; Kiguchi, Masao; Fujioka, Chikako; Kitagawa, Toshiro; Ito, Katsuhide

    2009-01-01

    Objective To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT. Materials and Methods One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD). Results The estimated effective dose was 1.5 ± 0.2 mSv. The mean heart rate was 63 ± 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 ± 4.5 kg/m2 (range, 15.5-42.3 kg/m2). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 ± 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level. Conclusion The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05). PMID:19568461

  12. The role of 64-slice CT following perfusion with iohexol via the hepatopancreatic ampulla in assessing pancreaticobiliary junctions.

    PubMed

    Guo, Wan-Liang; Bai, Xue-Jie; Huang, Shun-Gen; Fang, Lin; Wang, Jian

    2015-07-01

    The aim of this study was to delineate the structure of the pancreatic and biliary ducts in premature infants using a novel imaging method. The duodenal papillae of 30 premature infant cadavers were dissected. The pancreatic and biliary ducts were visualized using 64-detector multislice spiral computed tomography (MSCT). Contrast agent was injected into the duodenal papilla via the hepatopancreatic ampulla of Vater. MSCT scanning revealed both the pancreatic and biliary ducts as well as the common channel in 18 cases. The bile duct was visualized in the remaining 12 cases. Four patterns of the pancreaticobiliary ductal junction were noted: Y-type (73.3%), U-type (13.3%), V-type (6.7%), and II-type (6.7%). The results showed that MSCT and three-dimensional reconstruction can be used to visualize the junction pattern and common channel of the pancreatic and biliary ducts, and the structure of the surrounding tissue, in premature infants.

  13. Evaluation of organ doses and specific k effective dose of 64-slice CT thorax examination using an adult anthropomorphic phantom

    NASA Astrophysics Data System (ADS)

    Hashim, S.; Karim, M. K. A.; Bakar, K. A.; Sabarudin, A.; Chin, A. W.; Saripan, M. I.; Bradley, D. A.

    2016-09-01

    The magnitude of radiation dose in computed tomography (CT) depends on the scan acquisition parameters, investigated herein using an anthropomorphic phantom (RANDO®) and thermoluminescence dosimeters (TLD). Specific interest was in the organ doses resulting from CT thorax examination, the specific k coefficient for effective dose estimation for particular protocols also being determined. For measurement of doses representing five main organs (thyroid, lung, liver, esophagus and skin), TLD-100 (LiF:Mg, Ti) were inserted into selected holes in a phantom slab. Five CT thorax protocols were investigated, one routine (R1) and four that were modified protocols (R2 to R5). Organ doses were ranked from greatest to least, found to lie in the order: thyroid>skin>lung>liver>breast. The greatest dose, for thyroid at 25 mGy, was that in use of R1 while the lowest, at 8.8 mGy, was in breast tissue using R3. Effective dose (E) was estimated using three standard methods: the International Commission on Radiological Protection (ICRP)-103 recommendation (E103), the computational phantom CT-EXPO (E(CTEXPO)) method, and the dose-length product (DLP) based approach. E103 k factors were constant for all protocols, ~8% less than that of the universal k factor. Due to inconsistency in tube potential and pitch factor the k factors from CTEXPO were found to vary between 0.015 and 0.010 for protocols R3 and R5. With considerable variation between scan acquisition parameters and organ doses, optimization of practice is necessary in order to reduce patient organ dose.

  14. Computational approaches to understand cardiac electrophysiology and arrhythmias

    PubMed Central

    Roberts, Byron N.; Yang, Pei-Chi; Behrens, Steven B.; Moreno, Jonathan D.

    2012-01-01

    Cardiac rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. These impulses spread throughout the cardiac muscle to manifest as electrical waves in the whole heart. Regularity of electrical waves is critically important since they signal the heart muscle to contract, driving the primary function of the heart to act as a pump and deliver blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. For more than 50 years, mathematically based models of cardiac electrical activity have been used to improve understanding of basic mechanisms of normal and abnormal cardiac electrical function. Computer-based modeling approaches to understand cardiac activity are uniquely helpful because they allow for distillation of complex emergent behaviors into the key contributing components underlying them. Here we review the latest advances and novel concepts in the field as they relate to understanding the complex interplay between electrical, mechanical, structural, and genetic mechanisms during arrhythmia development at the level of ion channels, cells, and tissues. We also discuss the latest computational approaches to guiding arrhythmia therapy. PMID:22886409

  15. Images as drivers of progress in cardiac computational modelling.

    PubMed

    Lamata, Pablo; Casero, Ramón; Carapella, Valentina; Niederer, Steve A; Bishop, Martin J; Schneider, Jürgen E; Kohl, Peter; Grau, Vicente

    2014-08-01

    Computational models have become a fundamental tool in cardiac research. Models are evolving to cover multiple scales and physical mechanisms. They are moving towards mechanistic descriptions of personalised structure and function, including effects of natural variability. These developments are underpinned to a large extent by advances in imaging technologies. This article reviews how novel imaging technologies, or the innovative use and extension of established ones, integrate with computational models and drive novel insights into cardiac biophysics. In terms of structural characterization, we discuss how imaging is allowing a wide range of scales to be considered, from cellular levels to whole organs. We analyse how the evolution from structural to functional imaging is opening new avenues for computational models, and in this respect we review methods for measurement of electrical activity, mechanics and flow. Finally, we consider ways in which combined imaging and modelling research is likely to continue advancing cardiac research, and identify some of the main challenges that remain to be solved.

  16. Computational modeling of cardiac hemodynamics: Current status and future outlook

    NASA Astrophysics Data System (ADS)

    Mittal, Rajat; Seo, Jung Hee; Vedula, Vijay; Choi, Young J.; Liu, Hang; Huang, H. Howie; Jain, Saurabh; Younes, Laurent; Abraham, Theodore; George, Richard T.

    2016-01-01

    The proliferation of four-dimensional imaging technologies, increasing computational speeds, improved simulation algorithms, and the widespread availability of powerful computing platforms is enabling simulations of cardiac hemodynamics with unprecedented speed and fidelity. Since cardiovascular disease is intimately linked to cardiovascular hemodynamics, accurate assessment of the patient's hemodynamic state is critical for the diagnosis and treatment of heart disease. Unfortunately, while a variety of invasive and non-invasive approaches for measuring cardiac hemodynamics are in widespread use, they still only provide an incomplete picture of the hemodynamic state of a patient. In this context, computational modeling of cardiac hemodynamics presents as a powerful non-invasive modality that can fill this information gap, and significantly impact the diagnosis as well as the treatment of cardiac disease. This article reviews the current status of this field as well as the emerging trends and challenges in cardiovascular health, computing, modeling and simulation and that are expected to play a key role in its future development. Some recent advances in modeling and simulations of cardiac flow are described by using examples from our own work as well as the research of other groups.

  17. Influence of computer work under time pressure on cardiac activity.

    PubMed

    Shi, Ping; Hu, Sijung; Yu, Hongliu

    2015-03-01

    Computer users are often under stress when required to complete computer work within a required time. Work stress has repeatedly been associated with an increased risk for cardiovascular disease. The present study examined the effects of time pressure workload during computer tasks on cardiac activity in 20 healthy subjects. Heart rate, time domain and frequency domain indices of heart rate variability (HRV) and Poincaré plot parameters were compared among five computer tasks and two rest periods. Faster heart rate and decreased standard deviation of R-R interval were noted in response to computer tasks under time pressure. The Poincaré plot parameters showed significant differences between different levels of time pressure workload during computer tasks, and between computer tasks and the rest periods. In contrast, no significant differences were identified for the frequency domain indices of HRV. The results suggest that the quantitative Poincaré plot analysis used in this study was able to reveal the intrinsic nonlinear nature of the autonomically regulated cardiac rhythm. Specifically, heightened vagal tone occurred during the relaxation computer tasks without time pressure. In contrast, the stressful computer tasks with added time pressure stimulated cardiac sympathetic activity.

  18. Verification of computational models of cardiac electro-physiology.

    PubMed

    Pathmanathan, Pras; Gray, Richard A

    2014-05-01

    For computational models of cardiac activity to be used in safety-critical clinical decision-making, thorough and rigorous testing of the accuracy of predictions is required. The field of 'verification, validation and uncertainty quantification' has been developed to evaluate the credibility of computational predictions. The first stage, verification, is the evaluation of how well computational software correctly solves the underlying mathematical equations. The aim of this paper is to introduce novel methods for verifying multi-cellular electro-physiological solvers, a crucial first stage for solvers to be used with confidence in clinical applications. We define 1D-3D model problems with exact solutions for each of the monodomain, bidomain, and bidomain-with-perfusing-bath formulations of cardiac electro-physiology, which allow for the first time the testing of cardiac solvers against exact errors on fully coupled problems in all dimensions. These problems are carefully constructed so that they can be easily run using a general solver and can be used to greatly increase confidence that an implementation is correct, which we illustrate by testing one major solver, 'Chaste', on the problems. We then perform case studies on calculation verification (also known as solution verification) for two specific applications. We conclude by making several recommendations regarding verification in cardiac modelling.

  19. Extracellular volume quantification by dynamic equilibrium cardiac computed tomography in cardiac amyloidosis

    PubMed Central

    Treibel, Thomas A.; Bandula, Steve; Fontana, Marianna; White, Steven K.; Gilbertson, Janet A.; Herrey, Anna S.; Gillmore, Julian D.; Punwani, Shonit; Hawkins, Philip N.; Taylor, Stuart A.; Moon, James C.

    2015-01-01

    Background Cardiac involvement determines outcome in patients with systemic amyloidosis. There is major unmet need for quantification of cardiac amyloid burden, which is currently only met in part through semi-quantitative bone scintigraphy or Cardiovascular Magnetic Resonance (CMR), which measures ECVCMR. Other accessible tests are needed. Objectives To develop cardiac computed tomography to diagnose and quantify cardiac amyloidosis by measuring the myocardial Extracellular Volume, ECVCT. Methods Twenty-six patients (21 male, 64 ± 14 years) with a biopsy-proven systemic amyloidosis (ATTR n = 18; AL n = 8) were compared with twenty-seven patients (19 male, 68 ± 8 years) with severe aortic stenosis (AS). All patients had undergone echocardiography, bone scintigraphy, NT-pro-BNP measurement and EQ-CMR. Dynamic Equilibrium CT (DynEQ-CT) was performed using a prospectively gated cardiac scan prior to and after (5 and 15 minutes) a standard Iodixanol (1 ml/kg) bolus to measure ECVCT. ECVCT was compared to the reference ECVCMR and conventional amyloid measures: bone scintigraphy and clinical markers of cardiac amyloid severity (NT-pro-BNP, Troponin, LVEF, LV mass, LA and RA area). Results ECVCT and ECVCMR results were well correlated (r2 = 0.85 vs r2 = 0.74 for 5 and 15 minutes post bolus respectively). ECVCT was higher in amyloidosis than AS (0.54 ± 0.11 vs 0.28 ± 0.04, p<0.001) with no overlap. ECVCT tracked clinical markers of cardiac amyloid severity (NT-pro-BNP, Troponin, LVEF, LV mass, LA and RA area), and bone scintigraphy amyloid burden (p<0.001). Conclusion Dynamic Equilibrium CT, a 5 minute contrast-enhanced gated cardiac CT, has potential for non-invasive diagnosis and quantification of cardiac amyloidosis. PMID:26209459

  20. Images as drivers of progress in cardiac computational modelling

    PubMed Central

    Lamata, Pablo; Casero, Ramón; Carapella, Valentina; Niederer, Steve A.; Bishop, Martin J.; Schneider, Jürgen E.; Kohl, Peter; Grau, Vicente

    2014-01-01

    Computational models have become a fundamental tool in cardiac research. Models are evolving to cover multiple scales and physical mechanisms. They are moving towards mechanistic descriptions of personalised structure and function, including effects of natural variability. These developments are underpinned to a large extent by advances in imaging technologies. This article reviews how novel imaging technologies, or the innovative use and extension of established ones, integrate with computational models and drive novel insights into cardiac biophysics. In terms of structural characterization, we discuss how imaging is allowing a wide range of scales to be considered, from cellular levels to whole organs. We analyse how the evolution from structural to functional imaging is opening new avenues for computational models, and in this respect we review methods for measurement of electrical activity, mechanics and flow. Finally, we consider ways in which combined imaging and modelling research is likely to continue advancing cardiac research, and identify some of the main challenges that remain to be solved. PMID:25117497

  1. Computational models reduce complexity and accelerate insight into cardiac signaling networks.

    PubMed

    Yang, Jason H; Saucerman, Jeffrey J

    2011-01-07

    Cardiac signaling networks exhibit considerable complexity in size and connectivity. The intrinsic complexity of these networks complicates the interpretation of experimental findings. This motivates new methods for investigating the mechanisms regulating cardiac signaling networks and the consequences these networks have on cardiac physiology and disease. Next-generation experimental techniques are also generating a wealth of genomic and proteomic data that can be difficult to analyze or interpret. Computational models are poised to play a key role in addressing these challenges. Computational models have a long history in contributing to the understanding of cardiac physiology and are useful for identifying biological mechanisms, inferring multiscale consequences to cell signaling activities and reducing the complexity of large data sets. Models also integrate well with experimental studies to explain experimental observations and generate new hypotheses. Here, we review the contributions computational modeling approaches have made to the analysis of cardiac signaling networks and forecast opportunities for computational models to accelerate cardiac signaling research.

  2. Computational modeling of muscular thin films for cardiac repair

    NASA Astrophysics Data System (ADS)

    Böl, Markus; Reese, Stefanie; Parker, Kevin Kit; Kuhl, Ellen

    2009-03-01

    Motivated by recent success in growing biohybrid material from engineered tissues on synthetic polymer films, we derive a computational simulation tool for muscular thin films in cardiac repair. In this model, the polydimethylsiloxane base layer is simulated in terms of microscopically motivated tetrahedral elements. Their behavior is characterized through a volumetric contribution and a chain contribution that explicitly accounts for the polymeric microstructure of networks of long chain molecules. Neonatal rat ventricular cardiomyocytes cultured on these polymeric films are modeled with actively contracting truss elements located on top of the sheet. The force stretch response of these trusses is motivated by the cardiomyocyte force generated during active contraction as suggested by the filament sliding theory. In contrast to existing phenomenological models, all material parameters of this novel model have a clear biophyisical interpretation. The predictive features of the model will be demonstrated through the simulation of muscular thin films. First, the set of parameters will be fitted for one particular experiment documented in the literature. This parameter set is then used to validate the model for various different experiments. Last, we give an outlook of how the proposed simulation tool could be used to virtually predict the response of multi-layered muscular thin films. These three-dimensional constructs show a tremendous regenerative potential in repair of damaged cardiac tissue. The ability to understand, tune and optimize their structural response is thus of great interest in cardiovascular tissue engineering.

  3. Usefulness of Age and Gender in the Early Triage of Patients with Acute Chest Pain Having Cardiac Computed Tomographic Angiography

    PubMed Central

    Bamberg, Fabian; Truong, Quynh A.; Blankstein, Ron; Nasir, Khurram; Lee, Hang; Rogers, Ian S.; Achenbach, Stephan; Brady, Thomas J.; Nagurney, John T.; Reiser, Maximilian F.; Hoffmann, Udo

    2009-01-01

    To identify age- and gender- specific sub-populations of patients with acute chest pain in whom coronary CT angiography (CTA) yields the highest diagnostic benefit. Subjects with acute chest pain and an inconclusive initial evaluation (non-diagnostic electrocardiogram, negative cardiac biomarkers) underwent contrast-enhanced 64-slice CT coronary angiography as part of an observational cohort study. Independent investigators determined the presence of significant coronary stenosis (>50% luminal narrowing) and the occurrence of acute coronary syndrome (ACS) during index hospitalization. We determined diagnostic accuracy and impact on pretest probability of ACS using Bayes' theorem. Among 368 patients (52.7±12 age, 61% males), 8% had ACS. Presence of significant coronary stenosis by CT and the occurrence of ACS increased with age for both men and women (p<0.001). Cardiac CTA was highly sensitive and specific in women younger than 65 years of age (sensitivity: 100% and specificity >87%) and men younger than 55 years of age (sensitivity: 100% in <45 and 80% in 45-54 years old men; specificity: >88.2%). Moreover, in these patients coronary CTA led to restratification from low to high (for a positive CTA) or from low to very low risk (for a negative CTA). In contrast, a negative CTA result did not result in restratification to low risk category in women >65 and men >55 years of age. In conclusion, this analysis provides initial evidence that men <55 and women <65 might benefit more from cardiac CTA than elderly patients. Thus, age and gender may serve as simple criteria to appropriately select patients who may derive the greatest diagnostic benefit from coronary CTA in the setting of acute chest pain. PMID:19840556

  4. A 64-slice multi-detector CT scan could evaluate the change of the left atrial appendage thrombi of the atrial fibrillation patient, which was reduced by warfarin therapy.

    PubMed

    Takeuchi, Hidekazu

    2011-08-19

    Curable cause of stroke is the left atrial appendage (LAA) thrombi of atrial fibrillation (AF) patients. Some AF patients have the LAA thrombi. It is very important to cure AF patients by warfarin. Transoesophageal echocardiography (TOE) is the usual clinical tool to detect the LAA thrombi. Recently, a 64-slice multi-detector CT (64-MDCT) scan enables us to display the LAA thrombi more easily than TOE. I reported a case that a 64-MDCT scan had been used successfully in displaying the change of the LAA thrombi reduced by warfarin therapy. The size of the LAA thrombi was reduced from 25.2 mm × 19.3 mm (figure 1) to 22.1 mm × 14.8 mm (figure 2) after the 3-month warfarin therapy. It was useful to estimate the LAA thrombi by a 64-MDCT scan to estimate LAA thrombi itself and the change of LAA thrombi to evaluate the effectiveness of warfarin therapy.

  5. Standardized medical terminology for cardiac computed tomography: a report of the Society of Cardiovascular Computed Tomography.

    PubMed

    Weigold, Wm Guy; Abbara, Suhny; Achenbach, Stephan; Arbab-Zadeh, Armin; Berman, Daniel; Carr, J Jeffrey; Cury, Ricardo C; Halliburton, Sandra S; McCollough, Cynthia H; Taylor, Allen J

    2011-01-01

    Since the emergence of cardiac computed tomography (CT) at the turn of the 21st century, there has been an exponential growth in research and clinical development of the technique, with contributions from investigators and clinicians from varied backgrounds: physics and engineering, informatics, cardiology, and radiology. However, terminology for the field is not unified. As a consequence, there are multiple abbreviations for some terms, multiple terms for some concepts, and some concepts that lack clear definitions and/or usage. In an effort to aid the work of all those who seek to contribute to the literature, clinical practice, and investigation of the field, the Society of Cardiovascular Computed Tomography sets forth a standard set of medical terms commonly used in clinical and investigative practice of cardiac CT.

  6. Design of a specialized computer for on-line monitoring of cardiac stroke volume

    NASA Technical Reports Server (NTRS)

    Webb, J. A., Jr.; Gebben, V. D.

    1972-01-01

    The design of a specialized analog computer for on-line determination of cardiac stroke volume by means of a modified version of the pressure pulse contour method is presented. The design consists of an analog circuit for computation and a timing circuit for detecting necessary events on the pressure waveform. Readouts of arterial pressures, systolic duration, heart rate, percent change in stroke volume, and percent change in cardiac output are provided for monitoring cardiac patients. Laboratory results showed that computational accuracy was within 3 percent, while animal experiments verified the operational capability of the computer. Patient safety considerations are also discussed.

  7. Human cardiac systems electrophysiology and arrhythmogenesis: iteration of experiment and computation.

    PubMed

    Holzem, Katherine M; Madden, Eli J; Efimov, Igor R

    2014-11-01

    Human cardiac electrophysiology (EP) is a unique system for computational modelling at multiple scales. Due to the complexity of the cardiac excitation sequence, coordinated activity must occur from the single channel to the entire myocardial syncytium. Thus, sophisticated computational algorithms have been developed to investigate cardiac EP at the level of ion channels, cardiomyocytes, multicellular tissues, and the whole heart. Although understanding of each functional level will ultimately be important to thoroughly understand mechanisms of physiology and disease, cardiac arrhythmias are expressly the product of cardiac tissue-containing enough cardiomyocytes to sustain a reentrant loop of activation. In addition, several properties of cardiac cellular EP, that are critical for arrhythmogenesis, are significantly altered by cell-to-cell coupling. However, relevant human cardiac EP data, upon which to develop or validate models at all scales, has been lacking. Thus, over several years, we have developed a paradigm for multiscale human heart physiology investigation and have recovered and studied over 300 human hearts. We have generated a rich experimental dataset, from which we better understand mechanisms of arrhythmia in human and can improve models of human cardiac EP. In addition, in collaboration with computational physiologists, we are developing a database for the deposition of human heart experimental data, including thorough experimental documentation. We anticipate that accessibility to this human heart dataset will further human EP computational investigations, as well as encourage greater data transparency within the field of cardiac EP.

  8. Human cardiac systems electrophysiology and arrhythmogenesis: iteration of experiment and computation

    PubMed Central

    Holzem, Katherine M.; Madden, Eli J.; Efimov, Igor R.

    2014-01-01

    Human cardiac electrophysiology (EP) is a unique system for computational modelling at multiple scales. Due to the complexity of the cardiac excitation sequence, coordinated activity must occur from the single channel to the entire myocardial syncytium. Thus, sophisticated computational algorithms have been developed to investigate cardiac EP at the level of ion channels, cardiomyocytes, multicellular tissues, and the whole heart. Although understanding of each functional level will ultimately be important to thoroughly understand mechanisms of physiology and disease, cardiac arrhythmias are expressly the product of cardiac tissue—containing enough cardiomyocytes to sustain a reentrant loop of activation. In addition, several properties of cardiac cellular EP, that are critical for arrhythmogenesis, are significantly altered by cell-to-cell coupling. However, relevant human cardiac EP data, upon which to develop or validate models at all scales, has been lacking. Thus, over several years, we have developed a paradigm for multiscale human heart physiology investigation and have recovered and studied over 300 human hearts. We have generated a rich experimental dataset, from which we better understand mechanisms of arrhythmia in human and can improve models of human cardiac EP. In addition, in collaboration with computational physiologists, we are developing a database for the deposition of human heart experimental data, including thorough experimental documentation. We anticipate that accessibility to this human heart dataset will further human EP computational investigations, as well as encourage greater data transparency within the field of cardiac EP. PMID:25362174

  9. Multiple cardiac lipomas and pericardial lipomatosis: multidedector-row computer tomography findings.

    PubMed

    Sanal, Hatice Tuba; Kocaoğlu, Murat; Yildirim, Düzgün; Ors, Fatih

    2007-10-01

    Being rare tumors of the heart, cardiac lipomas are usually discovered incidentally during non-cardiac-related examinations of the chest. Although they are reported to be typically solitary, multiplicity has been described in tuberosclerosis patients. Here we reported the multidedector-row computer tomography (MDCT) findings of a nontuberosclerosis case with multiple cardiac lipomas along with pericardial lipomatosis, who presented with symptoms of left heart failure after a hysterectomy surgery but otherwise healthy before that operation.

  10. Analysis of left atrial respiratory and cardiac motion for cardiac ablation therapy

    NASA Astrophysics Data System (ADS)

    Rettmann, M. E.; Holmes, D. R.; Johnson, S. B.; Lehmann, H. I.; Robb, R. A.; Packer, D. L.

    2015-03-01

    Cardiac ablation therapy is often guided by models built from preoperative computed tomography (CT) or magnetic resonance imaging (MRI) scans. One of the challenges in guiding a procedure from a preoperative model is properly synching the preoperative models with cardiac and respiratory motion through computational motion models. In this paper, we describe a methodology for evaluating cardiac and respiratory motion in the left atrium and pulmonary veins of a beating canine heart. Cardiac catheters were used to place metal clips within and near the pulmonary veins and left atrial appendage under fluoroscopic and ultrasound guidance and a contrast-enhanced, 64-slice multidetector CT scan was collected with the clips in place. Each clip was segmented from the CT scan at each of the five phases of the cardiac cycle at both end-inspiration and end-expiration. The centroid of each segmented clip was computed and used to evaluate both cardiac and respiratory motion of the left atrium. A total of three canine studies were completed, with 4 clips analyzed in the first study, 5 clips in the second study, and 2 clips in the third study. Mean respiratory displacement was 0.2+/-1.8 mm in the medial/lateral direction, 4.7+/-4.4 mm in the anterior/posterior direction (moving anterior on inspiration), and 9.0+/-5.0 mm superior/inferior (moving inferior with inspiration). At end inspiration, the mean left atrial cardiac motion at the clip locations was 1.5+/-1.3 mm in the medial/lateral direction, and 2.1+/-2.0 mm in the anterior/posterior and 1.3+/-1.2 mm superior/inferior directions. At end expiration, the mean left atrial cardiac motion at the clip locations was 2.0+/-1.5mm in the medial/lateral direction, 3.0+/-1.8mm in the anterior/posterior direction, and 1.5+/-1.5 mm in the superior/inferior directions.

  11. Intraindividual comparison of gadolinium- and iodine-enhanced 64-slice multidetector CT pulmonary angiography for the detection of pulmonary embolism in a porcine model.

    PubMed

    Henes, Frank Oliver Gerhard; Groth, Michael; Begemann, Philipp G C; Adam, Gerhard; Regier, Marc

    2011-06-01

    This study is an evaluation of the diagnostic accuracy of gadolinium-enhanced computed tomography pulmonary angiography (CTPA) for the detection of pulmonary embolism (PE) in comparison with iodine-enhanced CTPA. PE was induced in five anesthetized pigs by administration of blood clots through an 11-F catheter inside the jugular vein. Animals underwent CTPA in breathhold with i.v. bolus injection of 50 ml gadopentetate dimeglumine (0.4 mmol/kg, 4 ml/s). Subsequently, CTPA was performed using the same imaging parameters but under administration of 70 ml nonionic iodinated contrast material (400 mg/ml, 4 ml/s). All images were reconstructed with 1 mm slice thickness. A consensus readout of the iodium-enhanced CTPAs by both radiologists served as reference standard. Gadolinium-enhanced CTPAs were evaluated independently by two experienced radiologists, and differences in detection rate between both contrast agents were assessed on a per embolus basis using the Wilcoxon signed-rank test. Interobserver agreement was determined by calculation of қ values. PE was diagnosed independently by both readers in all five pigs by the use of gadolinium-enhanced CTPA. Out of 60 pulmonary emboli detected in the iodine-enhanced scans, 47 (78.3%; reader 1) and 44 (62.8%; reader 2) emboli were detected by the use of gadolinium. All 13 (100%) emboli in lobar arteries (by both readers) and 26 (reader 1) and 25 (reader 2) out of 27 emboli (96.3% and 92.6%) in segmental arteries were detected by the use of the gadolinium-enhanced CTPA. In subsegmental arteries, only 8 (40%; reader 1) and 6 (30%; reader 2) out of 20 emboli were detected by the gadolinium-enhanced CTPA. By comparing both scans on a per vessel basis (Wilcoxon test), Gd-enhanced CTPA was significantly inferior in emboli detection on subsegmental level (P < 0.0001). The interobserver agreement was excellent on lobar and segmental level (қ = 1.0 and 0.93, respectively), whereas readers only reached moderate

  12. Cardiac amyloidosis imaged by dual-source computed tomography.

    PubMed

    Marwan, Mohamed; Pflederer, Tobias; Ropers, Dieter; Schmid, Michael; Wasmeier, Gerald; Söder, Stephan; Daniel, Werner G; Achenbach, Stephan

    2008-11-01

    The ability of contrast-enhanced CT to detect "late enhancement" in a fashion similar to magnetic resonance imaging has been reported previously. Typical myocardial distribution patterns of "late enhancement" have been described for MRI. The same patterns can be observed in CT imaging, albeit at a lower signal to noise ratio. We report a case of cardiac amyloidosis with a typical pattern of subendocardial, circumferential late enhancement in all four cardiac chambers.

  13. Uncertainty and variability in computational and mathematical models of cardiac physiology

    PubMed Central

    Mirams, Gary R.; Pathmanathan, Pras; Gray, Richard A.; Challenor, Peter

    2016-01-01

    Key points Mathematical and computational models of cardiac physiology have been an integral component of cardiac electrophysiology since its inception, and are collectively known as the Cardiac Physiome.We identify and classify the numerous sources of variability and uncertainty in model formulation, parameters and other inputs that arise from both natural variation in experimental data and lack of knowledge.The impact of uncertainty on the outputs of Cardiac Physiome models is not well understood, and this limits their utility as clinical tools.We argue that incorporating variability and uncertainty should be a high priority for the future of the Cardiac Physiome.We suggest investigating the adoption of approaches developed in other areas of science and engineering while recognising unique challenges for the Cardiac Physiome; it is likely that novel methods will be necessary that require engagement with the mathematics and statistics community. Abstract The Cardiac Physiome effort is one of the most mature and successful applications of mathematical and computational modelling for describing and advancing the understanding of physiology. After five decades of development, physiological cardiac models are poised to realise the promise of translational research via clinical applications such as drug development and patient‐specific approaches as well as ablation, cardiac resynchronisation and contractility modulation therapies. For models to be included as a vital component of the decision process in safety‐critical applications, rigorous assessment of model credibility will be required. This White Paper describes one aspect of this process by identifying and classifying sources of variability and uncertainty in models as well as their implications for the application and development of cardiac models. We stress the need to understand and quantify the sources of variability and uncertainty in model inputs, and the impact of model structure and complexity and

  14. Preliminary Experimental Results on Controlled Cardiac Computed Tomography: A Phantom Study

    PubMed Central

    Lu, Yang; Cai, Zhijun; Wang, Ge; Zhao, Jun; Bai, Er-Wei

    2010-01-01

    In this paper, we present the preliminary experimental results on controlled cardiac computed tomography (CT), which aims to reduce the motion artifacts by means of controlling the x-ray source rotation speed. An innovative cardiac phantom enables us to perform this experiment without modifying the scanner. It is the first experiment on the cardiac CT with speed controlled x-ray source. Experimental results demonstrate that the proposed method successfully separates the phantom images at different phases (improve the temporal resolution) though controlling the x-ray speed. PMID:19696470

  15. Evaluating the Effectiveness of an Interactive Multimedia Computer-based Patient Education Program in Cardiac Rehabilitation.

    ERIC Educational Resources Information Center

    Jenny, Ng Yuen Yee; Fai, Tam Sing

    2001-01-01

    A study compared 48 cardiac patients who used an interactive multimedia computer-assisted patient education program and 48 taught by tutorial. The computer-assisted instructional method resulted in significantly better knowledge about exercise and self-management of chronic diseases. (Contains 29 references.) (JOW)

  16. Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation-based phase-to-phase deviation measure

    PubMed Central

    Wick, Carson A.; McClellan, James H.; Arepalli, Chesnal D.; Auffermann, William F.; Henry, Travis S.; Khosa, Faisal; Coy, Adam M.; Tridandapani, Srini

    2015-01-01

    Purpose: Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation-based, phase-to-phase deviation measure was developed. Methods: Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as well as the IVS was calculated using phase-to-phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board-certified radiologists, fellowship-trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic. Results: Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase-to-phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (PAGG) and IVS (PIV S) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (PCT). The one exception was the RCA, which improved for PAGG for 18 of the 20 subjects when compared to PCT (PCT = 2.48; PAGG = 2.07, p = 0

  17. Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation-based phase-to-phase deviation measure

    SciTech Connect

    Wick, Carson A.; McClellan, James H.; Arepalli, Chesnal D.; Auffermann, William F.; Henry, Travis S.; Khosa, Faisal; Coy, Adam M.; Tridandapani, Srini

    2015-02-15

    Purpose: Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation-based, phase-to-phase deviation measure was developed. Methods: Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as well as the IVS was calculated using phase-to-phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board-certified radiologists, fellowship-trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic. Results: Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase-to-phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (P{sub AGG}) and IVS (P{sub IV} {sub S}) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (P{sub CT}). The one exception was the RCA, which improved for P{sub AGG} for 18 of the 20 subjects when compared to P

  18. Computer Modelling for Better Diagnosis and Therapy of Patients by Cardiac Resynchronisation Therapy

    PubMed Central

    Pluijmert, Marieke; Lumens, Joost; Potse, Mark; Delhaas, Tammo; Auricchio, Angelo; Prinzen, Frits W

    2015-01-01

    Mathematical or computer models have become increasingly popular in biomedical science. Although they are a simplification of reality, computer models are able to link a multitude of processes to each other. In the fields of cardiac physiology and cardiology, models can be used to describe the combined activity of all ion channels (electrical models) or contraction-related processes (mechanical models) in potentially millions of cardiac cells. Electromechanical models go one step further by coupling electrical and mechanical processes and incorporating mechano-electrical feedback. The field of cardiac computer modelling is making rapid progress due to advances in research and the ever-increasing calculation power of computers. Computer models have helped to provide better understanding of disease mechanisms and treatment. The ultimate goal will be to create patient-specific models using diagnostic measurements from the individual patient. This paper gives a brief overview of computer models in the field of cardiology and mentions some scientific achievements and clinical applications, especially in relation to cardiac resynchronisation therapy (CRT). PMID:26835103

  19. Conversion of cardiac performance data in analog form for digital computer entry

    NASA Technical Reports Server (NTRS)

    Miller, R. L.

    1972-01-01

    A system is presented which will reduce analog cardiac performance data and convert the results to digital form for direct entry into a commercial time-shared computer. Circuits are discussed which perform the measurement and digital conversion of instantaneous systolic and diastolic parameters from the analog blood pressure waveform. Digital averaging over a selected number of heart cycles is performed on these measurements, as well as those of flow and heart rate. The determination of average cardiac output and peripheral resistance, including trends, is the end result after processing by digital computer.

  20. Ubiquitous Computing for Remote Cardiac Patient Monitoring: A Survey

    PubMed Central

    Kumar, Sunil; Kambhatla, Kashyap; Hu, Fei; Lifson, Mark; Xiao, Yang

    2008-01-01

    New wireless technologies, such as wireless LAN and sensor networks, for telecardiology purposes give new possibilities for monitoring vital parameters with wearable biomedical sensors, and give patients the freedom to be mobile and still be under continuous monitoring and thereby better quality of patient care. This paper will detail the architecture and quality-of-service (QoS) characteristics in integrated wireless telecardiology platforms. It will also discuss the current promising hardware/software platforms for wireless cardiac monitoring. The design methodology and challenges are provided for realistic implementation. PMID:18604301

  1. Cardiac lineage selection: integrating biological complexity into computational models.

    PubMed

    Foley, Ann

    2009-01-01

    The emergence of techniques to study developmental processes using systems biology approaches offers exciting possibilities for the developmental biologist. In particular cardiac lineage selection may be particularly amenable to these types of studies since the heart is the first fully functional organ to form in vertebrates. However there are many technical obstacles that need to be overcome for these studies to proceed. Here we present a brief overview of cardiomyocyte lineage deterimination and discuss how different aspects of this process either benefit from or present unique challenges for the development of systems biology approaches.

  2. Strategies for reduction of radiation dose in cardiac multislice CT.

    PubMed

    Paul, Jean-François; Abada, Hicham T

    2007-08-01

    Because cardiac computed tomography (CT) (mainly coronary CT angiography) is a very promising technique, used more and more for coronary artery evaluation, the benefits and risks of this new low-invasive technique must be balanced. Radiation dose is a major concern for coronary CT angiography, especially in case of repeated examinations or in particular subgroups of patients (for example young female patients). Radiation dose to patient tends to increase from 16- to 64-slice CT. Radiation exposure in ECG-gated acquisitions may reach up to 40 mSv; considerable differences are attributable to the performance of CT machines, to technical dose-sparing tools, but also to radiological habits. Setting radiation dose at the lowest level possible should be a constant goal for the radiologist. Current technological tools are detailed in regard to their efficiency. Optimisation is necessary, by a judicious use of technological tools and also by individual adaptation of kV or mAs. This paper reviews the different current strategies for radiation dose reduction, keeping image quality constant. Data from the literature are discussed, and future technological developments are considered in regards to radiation dose reduction. The particular case of paediatric patients with congenital heart disease is also addressed.

  3. ASCI 2010 appropriateness criteria for cardiac computed tomography: a report of the Asian Society of Cardiovascular Imaging Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging Guideline Working Group.

    PubMed

    Tsai, I-Chen; Choi, Byoung Wook; Chan, Carmen; Jinzaki, Masahiro; Kitagawa, Kakuya; Yong, Hwan Seok; Yu, Wei

    2010-02-01

    In Asia, the healthcare system, populations and patterns of disease differ from Western countries. The current reports on the criteria for cardiac CT scans, provided by Western professional societies, are not appropriate for Asian cultures. The Asian Society of Cardiovascular Imaging, the only society dedicated to cardiovascular imaging in Asia, formed a Working Group and invited 23 Technical Panel members representing a variety of Asian countries to rate the 51 indications for cardiac CT in clinical practice in Asia. The indications were rated as 'appropriate' (7-9), 'uncertain' (4-6), or 'inappropriate' (1-3) on a scale of 1-9. The median score was used for the final result if there was no disagreement. The final ratings for indications were 33 appropriate, 14 uncertain and 4 inappropriate. And 20 of them are highly agreed (19 appropriate and 1 inappropriate). Specifically, the Asian representatives considered cardiac CT as an appropriate modality for Kawasaki disease and congenital heart diseases in follow up and in symptomatic patients. In addition, except for some specified conditions, cardiac CT was considered to be an appropriate modality for one-stop shop ischemic heart disease evaluation due to its general appropriateness in coronary, structure and function evaluation. This report is expected to have a significant impact on the clinical practice, research and reimbursement policy in Asia.

  4. Comprehensive Modeling and Visualization of Cardiac Anatomy and Physiology from CT Imaging and Computer Simulations.

    PubMed

    Xiong, Guanglei; Sun, Peng; Zhou, Haoyin; Ha, Seongmin; Hartaigh, Briain O; Truong, Quynh A; Min, James K

    2017-02-01

    In clinical cardiology, both anatomy and physiology are needed to diagnose cardiac pathologies. CT imaging and computer simulations provide valuable and complementary data for this purpose. However, it remains challenging to gain useful information from the large amount of high-dimensional diverse data. The current tools are not adequately integrated to visualize anatomic and physiologic data from a complete yet focused perspective. We introduce a new computer-aided diagnosis framework, which allows for comprehensive modeling and visualization of cardiac anatomy and physiology from CT imaging data and computer simulations, with a primary focus on ischemic heart disease. The following visual information is presented: (1) Anatomy from CT imaging: geometric modeling and visualization of cardiac anatomy, including four heart chambers, left and right ventricular outflow tracts, and coronary arteries; (2) Function from CT imaging: motion modeling, strain calculation, and visualization of four heart chambers; (3) Physiology from CT imaging: quantification and visualization of myocardial perfusion and contextual integration with coronary artery anatomy; (4) Physiology from computer simulation: computation and visualization of hemodynamics (e.g., coronary blood velocity, pressure, shear stress, and fluid forces on the vessel wall). Substantially, feedback from cardiologists have confirmed the practical utility of integrating these features for the purpose of computer-aided diagnosis of ischemic heart disease.

  5. Comprehensive Modeling and Visualization of Cardiac Anatomy and Physiology from CT Imaging and Computer Simulations

    PubMed Central

    Sun, Peng; Zhou, Haoyin; Ha, Seongmin; Hartaigh, Bríain ó; Truong, Quynh A.; Min, James K.

    2016-01-01

    In clinical cardiology, both anatomy and physiology are needed to diagnose cardiac pathologies. CT imaging and computer simulations provide valuable and complementary data for this purpose. However, it remains challenging to gain useful information from the large amount of high-dimensional diverse data. The current tools are not adequately integrated to visualize anatomic and physiologic data from a complete yet focused perspective. We introduce a new computer-aided diagnosis framework, which allows for comprehensive modeling and visualization of cardiac anatomy and physiology from CT imaging data and computer simulations, with a primary focus on ischemic heart disease. The following visual information is presented: (1) Anatomy from CT imaging: geometric modeling and visualization of cardiac anatomy, including four heart chambers, left and right ventricular outflow tracts, and coronary arteries; (2) Function from CT imaging: motion modeling, strain calculation, and visualization of four heart chambers; (3) Physiology from CT imaging: quantification and visualization of myocardial perfusion and contextual integration with coronary artery anatomy; (4) Physiology from computer simulation: computation and visualization of hemodynamics (e.g., coronary blood velocity, pressure, shear stress, and fluid forces on the vessel wall). Substantially, feedback from cardiologists have confirmed the practical utility of integrating these features for the purpose of computer-aided diagnosis of ischemic heart disease. PMID:26863663

  6. Advanced computer techniques for inverse modeling of electric current in cardiac tissue

    SciTech Connect

    Hutchinson, S.A.; Romero, L.A.; Diegert, C.F.

    1996-08-01

    For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

  7. Advanced Imaging of Athletes: Added Value of Coronary Computed Tomography and Cardiac Magnetic Resonance Imaging.

    PubMed

    Martinez, Matthew W

    2015-07-01

    Cardiac magnetic resonance imaging and cardiac computed tomographic angiography have become important parts of the armamentarium for noninvasive diagnosis of cardiovascular disease. Emerging technologies have produced faster imaging, lower radiation dose, improved spatial and temporal resolution, as well as a wealth of prognostic data to support usage. Investigating true pathologic disease as well as distinguishing normal from potentially dangerous is now increasingly more routine for the cardiologist in practice. This article investigates how advanced imaging technologies can assist the clinician when evaluating all athletes for pathologic disease that may put them at risk.

  8. Tetralogy of Fallot Cardiac Function Evaluation and Intelligent Diagnosis Based on Dual-Source Computed Tomography Cardiac Images.

    PubMed

    Cai, Ken; Rongqian, Yang; Li, Lihua; Xie, Zi; Ou, Shanxing; Chen, Yuke; Dou, Jianhong

    2016-05-01

    Tetralogy of Fallot (TOF) is the most common complex congenital heart disease (CHD) of the cyanotic type. Studies on ventricular functions have received an increasing amount of attention as the development of diagnosis and treatment technology for CHD continues to advance. Reasonable options for imaging examination and accurate assessment of preoperative and postoperative left ventricular functions of TOF patients are important in improving the cure rate of TOF radical operation, therapeutic evaluation, and judgment prognosis. Therefore, with the aid of dual-source computed tomography (DSCT), cardiac images with high temporal resolution and high definition, we measured the left ventricular time-volume curve using image data and calculating the left ventricular function parameters to conduct the preliminary evaluation on TOF patients. To comprehensively evaluate the cardiac function, the segmental ventricular wall function parameters were measured, and the measurement results were mapped to a bull's eye diagram to realize the standardization of segmental ventricular wall function evaluation. Finally, we introduced a new clustering method based on auto-regression model parameters and combined this method with Euclidean distance measurements to establish an intelligent diagnosis of TOF. The results of this experiment show that the TOF evaluation and the intelligent diagnostic methods proposed in this article are feasible.

  9. [Evaluation of cardiac tumors by multidetector computed tomography and magnetic resonance imaging].

    PubMed

    Mercado-Guzman, Marcela P; Meléndez-Ramírez, Gabriela; Castillo-Castellon, Francisco; Kimura-Hayama, Eric

    Cardiac tumors, are a rare pathology (0.002-0.3%) in all age groups, however, they have a clinic importance, due the affected organ. They are classified in primary (benign or malignant) and secondary (metastasis) types. Among primary type, mixoma, is the most common benign tumor, and sarcoma represents most of the malignant injuries. Cardiac metastasis are more frequent than primary tumors. Clinic effects of cardiac tumors are unspecific and vary according their location, size and agresivity. The use of Multidetector Computed Tomography (MDCT) and Magnetic Resonance Imaging (MRI) assist on the location, sizing, anatomical relationships and the compromise of adyacents structures, besides, MRI is useful for tissue characterization of the tumor. Due to the previous reasons, studies based on noninvasive cardiovascular imaging, have an important role on the characterization of these lesions and the differential diagnosis among them.

  10. Noninvasive computational imaging of cardiac electrophysiology for 3-D infarct.

    PubMed

    Wang, Linwei; Wong, Ken C L; Zhang, Heye; Liu, Huafeng; Shi, Pengcheng

    2011-04-01

    Myocardial infarction (MI) creates electrophysiologically altered substrates that are responsible for ventricular arrhythmias, such as tachycardia and fibrillation. The presence, size, location, and composition of infarct scar bear significant prognostic and therapeutic implications for individual subjects. We have developed a statistical physiological model-constrained framework that uses noninvasive body-surface-potential data and tomographic images to estimate subject-specific transmembrane-potential (TMP) dynamics inside the 3-D myocardium. In this paper, we adapt this framework for the purpose of noninvasive imaging, detection, and quantification of 3-D scar mass for postMI patients: the framework requires no prior knowledge of MI and converges to final subject-specific TMP estimates after several passes of estimation with intermediate feedback; based on the primary features of the estimated spatiotemporal TMP dynamics, we provide 3-D imaging of scar tissue and quantitative evaluation of scar location and extent. Phantom experiments were performed on a computational model of realistic heart-torso geometry, considering 87 transmural infarct scars of different sizes and locations inside the myocardium, and 12 compact infarct scars (extent between 10% and 30%) at different transmural depths. Real-data experiments were carried out on BSP and magnetic resonance imaging (MRI) data from four postMI patients, validated by gold standards and existing results. This framework shows unique advantage of noninvasive, quantitative, computational imaging of subject-specific TMP dynamics and infarct mass of the 3-D myocardium, with the potential to reflect details in the spatial structure and tissue composition/heterogeneity of 3-D infarct scar.

  11. Computer simulation of the reentrant cardiac arrhythmias in ischemic myocardium.

    PubMed

    Zhang, Hong; Yang, Lin; Jin, Yin-bin; Zhang, Zhen-xi; Huang, Yi-zhuo

    2005-09-30

    Computer simulation was performed to determine how reentrant activity could occur due to the spatial heterogeneity in refractoriness induced by the regional ischemia. Two regional ischemic models were developed by decreasing the intracellular ATP concentration, reducing conductance of the inward Na+ current and increasing the extracellular K+ concentration on the two-dimensional sheet. Operator splitting method was used to integrate the models. The vulnerability to reentry was estimated from the timings of premature stimuli on the constructed models, which could result in unidirectionally propagating action potentials. Two kinds of sustained spiral waves and their Pseudo-Electroscardiograms were observed in numerical simulation. The results showed that the dispersion of refractory period increased with ischemic aggravation, and led to augment of the vulnerable window. A permature stimulation within the vulnerable window could easily induce spiral reentry. The Pseudo-Electrocardiograms of the spiral waves exhibited monomorphic tachycardiac waveforms. Thus, the spatial heterogeneity in refractoriness could be a substrate for reentrant ventricular tachyarrhythmias on the regional ischemic tissue.

  12. Physiologic Assessment of Coronary Artery Disease by Cardiac Computed Tomography

    PubMed Central

    Kochar, Minisha

    2013-01-01

    Coronary artery disease (CAD) remains the leading cause of death and morbidity worldwide. To date, diagnostic evaluation of patients with suspected CAD has relied upon the use of physiologic non-invasive testing by stress electrocardiography, echocardiography, myocardial perfusion imaging (MPI) and magnetic resonance imaging. Indeed, the importance of physiologic evaluation of CAD has been highlighted by large-scale randomized trials that demonstrate the propitious benefit of an integrated anatomic-physiologic evaluation method by performing lesion-specific ischemia assessment by fractional flow reserve (FFR)-widely considered the "gold" standard for ischemia assessment-at the time of invasive angiography. Coronary CT angiography (CCTA) has emerged as an attractive non-invasive test for anatomic illustration of the coronary arteries and atherosclerotic plaque. In a series of prospective multicenter trials, CCTA has been proven as having high diagnostic performance for stenosis detection as compared to invasive angiography. Nevertheless, CCTA evaluation of obstructive stenoses is prone to overestimation of severity and further, detection of stenoses by CCTA does not reliably determine the hemodynamic significance of the visualized lesions. Recently, a series of technological innovations have advanced the possibility of CCTA to enable physiologic evaluation of CAD, thereby creating the potential of this test to provide an integrated anatomic-physiologic assessment of CAD. These advances include rest-stress MPI by CCTA as well as the use of computational fluid dynamics to non-invasively calculate FFR from a typically acquired CCTA. The purpose of this review is to summarize the most recent data addressing these 2 physiologic methods of CAD evaluation by CCTA. PMID:23964289

  13. Low fingertip temperature rebound measured by digital thermal monitoring strongly correlates with the presence and extent of coronary artery disease diagnosed by 64-slice multi-detector computed tomography.

    PubMed

    Ahmadi, Naser; Nabavi, Vahid; Nuguri, Vivek; Hajsadeghi, Fereshteh; Flores, Ferdinand; Akhtar, Mohammad; Kleis, Stanley; Hecht, Harvey; Naghavi, Morteza; Budoff, Matthew

    2009-10-01

    Previous studies showed strong correlations between low fingertip temperature rebound measured by digital thermal monitoring (DTM) during a 5 min arm-cuff induced reactive hyperemia and both the Framingham Risk Score (FRS), and coronary artery calcification (CAC) in asymptomatic populations. This study evaluates the correlation between DTM and coronary artery disease (CAD) measured by CT angiography (CTA) in symptomatic patients. It also investigates the correlation between CTA and a new index of neurovascular reactivity measured by DTM. 129 patients, age 63 +/- 9 years, 68% male, underwent DTM, CAC and CTA. Adjusted DTM indices in the occluded arm were calculated: temperature rebound: aTR and area under the temperature curve aTMP-AUC. DTM neurovascular reactivity (NVR) index was measured based on increased fingertip temperature in the non-occluded arm. Obstructive CAD was defined as >or=50% luminal stenosis, and normal as no stenosis and CAC = 0. Baseline fingertip temperature was not different across the groups. However, all DTM indices of vascular and neurovascular reactivity significantly decreased from normal to non-obstructive to obstructive CAD [(aTR 1.77 +/- 1.18 to 1.24 +/- 1.14 to 0.94 +/- 0.92) (P = 0.009), (aTMP-AUC: 355.6 +/- 242.4 to 277.4 +/- 182.4 to 184.4 +/- 171.2) (P = 0.001), (NVR: 161.5 +/- 147.4 to 77.6 +/- 88.2 to 48.8 +/- 63.8) (P = 0.015)]. After adjusting for risk factors, the odds ratio for obstructive CAD compared to normal in the lowest versus two upper tertiles of FRS, aTR, aTMP-AUC, and NVR were 2.41 (1.02-5.93), P = 0.05, 8.67 (2.6-9.4), P = 0.001, 11.62 (5.1-28.7), P = 0.001, and 3.58 (1.09-11.69), P = 0.01, respectively. DTM indices and FRS combined resulted in a ROC curve area of 0.88 for the prediction of obstructive CAD. In patients suspected of CAD, low fingertip temperature rebound measured by DTM significantly predicted CTA-diagnosed obstructive disease.

  14. Analysis of Pulmonary Vein Antrums Motion with Cardiac Contraction Using Dual-Source Computed Tomography

    PubMed Central

    de Guise, Jacques; Vu, Toni; Chartrand-Lefebvre, Carl; Blais, Danis; Lebeau, Martin; Nguyen, Nhu-Tram; Roberge, David

    2016-01-01

    Purpose: The purpose of the study was to determine the extent of displacement of the pulmonary vein antrums resulting from the intrinsic motion of the heart using 4D cardiac dual-source computed tomography (DSCT). Methods: Ten consecutive female patients were enrolled in this prospective planning study. In breath-hold, a contrast-injected cardiac 4-dimensional (4D) computed tomography (CT) synchronized to the electrocardiogram was obtained using a prospective sequential acquisition method including the extreme phases of systole and diastole. Right and left atrial fibrillation target volumes (CTVR and CTVL) were defined, with each target volume containing the antral regions of the superior and inferior pulmonary veins. Four points of interest were used as surrogates for the right superior and inferior pulmonary vein antrum (RSPVA and RIPVA) and the left superior and inferior pulmonary vein antrum (LSPVA and LIPVA). On our 4D post-processing workstation (MIM Maestro™, MIM Software Inc.), maximum displacement of each point of interest from diastole to systole was measured in the mediolateral (ML), anteroposterior (AP), and superoinferior (SI) directions. Results: Median age of the enrolled patients was 60 years (range, 56-71 years). Within the CTVR, the mean displacements of the superior and inferior surrogates were 3 mm vs. 1 mm (p=0.002), 2 mm vs. 0 mm (p= 0.001), and 3 mm vs. 0 mm (p=0.00001), in the ML, AP, and SI directions, respectively. On the left, mean absolute displacements of the LSPVA vs. LIPVA were similar at 4 mm vs. 1 mm (p=0.0008), 2 mm vs. 0 mm (p= 0.001), and 3 mm vs. 1 mm (p=0.00001) in the ML, AP, and SI directions. Conclusion: When isolated from breathing, cardiac contraction is associated with minimal inferior pulmonary veins motion and modest (1-6 mm) motion of the superior veins. Target deformation was thus of a magnitude similar or greater than target motion, limiting the potential gains of cardiac tracking. Optimal strategies for cardiac

  15. Computational Approaches to Understanding the Role of Fibroblast-Myocyte Interactions in Cardiac Arrhythmogenesis

    PubMed Central

    Brown, Tashalee R.; Krogh-Madsen, Trine; Christini, David J.

    2015-01-01

    The adult heart is composed of a dense network of cardiomyocytes surrounded by nonmyocytes, the most abundant of which are cardiac fibroblasts. Several cardiac diseases, such as myocardial infarction or dilated cardiomyopathy, are associated with an increased density of fibroblasts, that is, fibrosis. Fibroblasts play a significant role in the development of electrical and mechanical dysfunction of the heart; however the underlying mechanisms are only partially understood. One widely studied mechanism suggests that fibroblasts produce excess extracellular matrix, resulting in collagenous septa. These collagenous septa slow propagation, cause zig-zag conduction paths, and decouple cardiomyocytes resulting in a substrate for arrhythmia. Another emerging mechanism suggests that fibroblasts promote arrhythmogenesis through direct electrical interactions with cardiomyocytes via gap junctions. Due to the challenges of investigating fibroblast-myocyte coupling in native cardiac tissue, computational modeling and in vitro experiments have facilitated the investigation into the mechanisms underlying fibroblast-mediated changes in cardiomyocyte action potential morphology, conduction velocity, spontaneous excitability, and vulnerability to reentry. In this paper, we summarize the major findings of the existing computational studies investigating the implications of fibroblast-myocyte interactions in the normal and diseased heart. We then present investigations from our group into the potential role of voltage-dependent gap junctions in fibroblast-myocyte interactions. PMID:26601107

  16. Petascale computation performance of lightweight multiscale cardiac models using hybrid programming models.

    PubMed

    Pope, Bernard J; Fitch, Blake G; Pitman, Michael C; Rice, John J; Reumann, Matthias

    2011-01-01

    Future multiscale and multiphysics models must use the power of high performance computing (HPC) systems to enable research into human disease, translational medical science, and treatment. Previously we showed that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message passing processes (e.g. the message passing interface (MPI)) with multithreading (e.g. OpenMP, POSIX pthreads). The objective of this work is to compare the performance of such hybrid programming models when applied to the simulation of a lightweight multiscale cardiac model. Our results show that the hybrid models do not perform favourably when compared to an implementation using only MPI which is in contrast to our results using complex physiological models. Thus, with regards to lightweight multiscale cardiac models, the user may not need to increase programming complexity by using a hybrid programming approach. However, considering that model complexity will increase as well as the HPC system size in both node count and number of cores per node, it is still foreseeable that we will achieve faster than real time multiscale cardiac simulations on these systems using hybrid programming models.

  17. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update*

    PubMed Central

    Assunção, Fernanda Boldrini; de Oliveira, Diogo Costa Leandro; Souza, Vitor Frauches; Nacif, Marcelo Souto

    2016-01-01

    Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complementarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies. PMID:26929458

  18. Cardiac Magnetic Resonance and Computed Tomography in Hypertrophic Cardiomyopathy: an Update

    PubMed Central

    de Oliveira, Diogo Costa Leandro; Assunção, Fernanda Boldrini; dos Santos, Alair Agusto Sarmet Moreira Damas; Nacif, Marcelo Souto

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease and represents the main cause of sudden death in young patients. Cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) are noninvasive imaging methods with high sensitivity and specificity, useful for the establishment of diagnosis and prognosis of HCM, and for the screening of patients with subclinical phenotypes. The improvement of image analysis by CMR and CCT offers the potential to promote interventions aiming at stopping the natural course of the disease. This study aims to describe the role of RCM and CCT in the diagnosis and prognosis of HCM, and how these methods can be used in the management of these patients. PMID:27305111

  19. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update.

    PubMed

    Assunção, Fernanda Boldrini; de Oliveira, Diogo Costa Leandro; Souza, Vitor Frauches; Nacif, Marcelo Souto

    2016-01-01

    Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complementarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies.

  20. The precision of a special purpose analog computer in clinical cardiac output determination.

    PubMed Central

    Sullivan, F J; Mroz, E A; Miller, R E

    1975-01-01

    Three hundred dye-dilution curves taken during our first year of clinical experience with the Waters CO-4 cardiac output computer were analyzed to estimate the errors involved in its use. Provided that calibration is accurate and 5.0 mg of dye are injected for each curve, then the percentage standard deviation of measurement using this computer is about 8.7%. Included in this are the errors inherent in the computer, errors due to baseline drift, errors in the injection of dye and acutal variation of cardiac output over a series of successive determinations. The size of this error is comparable to that involved in manual calculation. The mean value of five successive curves will be within 10% of the real value in 99 cases out of 100. Advances in methodology and equipment are discussed which make calibration simpler and more accurate, and which should also improve the quality of computer determination. A list of suggestions is given to minimize the errors involved in the clinical use of this equipment. Images Fig. 4. PMID:1089394

  1. Patient-Specific Simulation of Cardiac Blood Flow From High-Resolution Computed Tomography.

    PubMed

    Lantz, Jonas; Henriksson, Lilian; Persson, Anders; Karlsson, Matts; Ebbers, Tino

    2016-12-01

    Cardiac hemodynamics can be computed from medical imaging data, and results could potentially aid in cardiac diagnosis and treatment optimization. However, simulations are often based on simplified geometries, ignoring features such as papillary muscles and trabeculae due to their complex shape, limitations in image acquisitions, and challenges in computational modeling. This severely hampers the use of computational fluid dynamics in clinical practice. The overall aim of this study was to develop a novel numerical framework that incorporated these geometrical features. The model included the left atrium, ventricle, ascending aorta, and heart valves. The framework used image registration to obtain patient-specific wall motion, automatic remeshing to handle topological changes due to the complex trabeculae motion, and a fast interpolation routine to obtain intermediate meshes during the simulations. Velocity fields and residence time were evaluated, and they indicated that papillary muscles and trabeculae strongly interacted with the blood, which could not be observed in a simplified model. The framework resulted in a model with outstanding geometrical detail, demonstrating the feasibility as well as the importance of a framework that is capable of simulating blood flow in physiologically realistic hearts.

  2. Cardiac kinematic parameters computed from video of in situ beating heart

    PubMed Central

    Fassina, Lorenzo; Rozzi, Giacomo; Rossi, Stefano; Scacchi, Simone; Galetti, Maricla; Lo Muzio, Francesco Paolo; Del Bianco, Fabrizio; Colli Franzone, Piero; Petrilli, Giuseppe; Faggian, Giuseppe; Miragoli, Michele

    2017-01-01

    Mechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial velocity and vorticity were analyzed by means of Particle Image Velocimetry tool. We validated our new technique by i) computational modeling of cardiac ischemia, ii) video recordings of ischemic/reperfused rat hearts, iii) videos of beating human hearts before and after coronary artery bypass graft, and iv) local Frank-Starling effect. In rats, we observed a decrement of kinematic parameters during acute ischemia and a significant increment in the same region after reperfusion. We detected similar behavior in operated patients. This modality adds important functional values on cardiac outcomes and supports the intervention in a contact-free and non-invasive mode. Moreover, it does not require particular operator-dependent skills.

  3. Cardiac single-photon emission-computed tomography using combinedcone-beam/fan-beam collimation

    SciTech Connect

    Gullberg, Grant T.; Zeng, Gengsheng L.

    2004-12-03

    The objective of this work is to increase system sensitivity in cardiac single-photon emission-computed tomography (SPECT) studies without increasing patient imaging time. For imaging the heart, convergent collimation offers the potential of increased sensitivity over that of parallel-hole collimation. However, if a cone-beam collimated gamma camera is rotated in a planar orbit, the projection data obtained are not complete. Two cone-beam collimators and one fan-beam collimator are used with a three-detector SPECT system. The combined cone-beam/fan-beam collimation provides a complete set of data for image reconstruction. The imaging geometry is evaluated using data acquired from phantom and patient studies. For the Jaszazck cardiac torso phantom experiment, the combined cone-beam/fan-beam collimation provided 1.7 times greater sensitivity than standard parallel-hole collimation (low-energy high-resolution collimators). Also, phantom and patient comparison studies showed improved image quality. The combined cone-beam/fan-beam imaging geometry with appropriate weighting of the two data sets provides improved system sensitivity while measuring sufficient data for artifact free cardiac images.

  4. Can Computer Tomography Predict Compromise of Cardiac Structures After Percutaneous Closure of Interatrial Septal Defects?

    PubMed Central

    Wagdi, Philipp

    2011-01-01

    Background Erosion of a cardiac structure after device closure of an interatrial septal communication (IASC-C), although rare, is a major and severe adverse event which may be underreported. On the other hand, unexplained episodes of transient chest pain occur more often and may be quite distressing. We sought to define the parameters relating the devices to the adjacent cardiac structures and to determine whether computer tomography (CT) could predict erosion of atrial or aortic wall or precordial pain symptoms occurring in the first months after device implantation. Methods Retrospective observational study of 20 patients who underwent CT for de novo chest pain occurring after IASC-C or as a diagnostic test for suspected or proven coronary artery disease (CAD). Clinical follow up was for 20.5 ± 17.6 (6-84) months. CT was done 18 ± 10 (2-28) weeks after IASC-C. Results Indentation of the aortic root was found in 11 (55%) patients, the left atrial wall in 13 (65%) and the right atrial wall in eight (40%) of patients. Contact without indentation was found in nine (45%), 6 (30%) and 11 (55%) of patients respectively. Conclusions Device indenting of the left and right atrial, as well as the aortic wall, occured in the majority of the patients examined after IASC-C. This finding may explain bouts of chest pain after the intervention in some patients, but does not predict clinically relevant erosion of a cardiac structure.

  5. Mechano-chemical Interactions in Cardiac Sarcomere Contraction: A Computational Modeling Study

    PubMed Central

    Lumens, Joost; Arts, Theo; Delhaas, Tammo

    2016-01-01

    We developed a model of cardiac sarcomere contraction to study the calcium-tension relationship in cardiac muscle. Calcium mediates cardiac contraction through its interactions with troponin (Tn) and subsequently tropomyosin molecules. Experimental studies have shown that a slight increase in intracellular calcium concentration leads to a rapid increase in sarcomeric tension. Though it is widely accepted that the rapid increase is not possible without the concept of cooperativity, the mechanism is debated. We use the hypothesis that there exists a base level of cooperativity intrinsic to the thin filament that is boosted by mechanical tension, i.e. a high level of mechanical tension in the thin filament impedes the unbinding of calcium from Tn. To test these hypotheses, we developed a computational model in which a set of three parameters and inputs of calcium concentration and sarcomere length result in output tension. Tension as simulated appeared in good agreement with experimentally measured tension. Our results support the hypothesis that high tension in the thin filament impedes Tn deactivation by increasing the energy required to detach calcium from the Tn. Given this hypothesis, the model predicted that the areas with highest tension, i.e. closest to the Z-disk end of the single overlap region, show the largest concentration of active Tn’s. PMID:27716775

  6. Use of Cardiac Computed Tomography for Ventricular Volumetry in Late Postoperative Patients with Tetralogy of Fallot

    PubMed Central

    Kim, Ho Jin; Mun, Da Na; Goo, Hyun Woo; Yun, Tae-Jin

    2017-01-01

    Background Cardiac computed tomography (CT) has emerged as an alternative to magnetic resonance imaging (MRI) for ventricular volumetry. However, the clinical use of cardiac CT requires external validation. Methods Both cardiac CT and MRI were performed prior to pulmonary valve implantation (PVI) in 11 patients (median age, 19 years) who had undergone total correction of tetralogy of Fallot during infancy. The simplified contouring method (MRI) and semiautomatic 3-dimensional region-growing method (CT) were used to measure ventricular volumes. Results All volumetric indices measured by CT and MRI generally correlated well with each other, except for the left ventricular end-systolic volume index (LV-ESVI), which showed the following correlations with the other indices: the right ventricular end-diastolic volume index (RV-EDVI) (r=0.88, p<0.001), the right ventricular end-systolic volume index (RV-ESVI) (r=0.84, p=0.001), the left ventricular end-diastolic volume index (LV-EDVI) (r=0.90, p=0.001), and the LV-ESVI (r=0.55, p=0.079). While the EDVIs measured by CT were significantly larger than those measured by MRI (median RV-EDVI: 197 mL/m2 vs. 175 mL/m2, p=0.008; median LV-EDVI: 94 mL/m2 vs. 92 mL/m2, p=0.026), no significant differences were found for the RV-ESVI or LV-ESVI. Conclusion The EDVIs measured by cardiac CT were greater than those measured by MRI, whereas the ESVIs measured by CT and MRI were comparable. The volumetric characteristics of these 2 diagnostic modalities should be taken into account when indications for late PVI after tetralogy of Fallot repair are assessed. PMID:28382264

  7. Morphological and Functional Evaluation of Quadricuspid Aortic Valves Using Cardiac Computed Tomography

    PubMed Central

    Song, Inyoung; Park, Jung Ah; Choi, Bo Hwa; Shin, Je Kyoun; Chee, Hyun Keun; Kim, Jun Seok

    2016-01-01

    Objective The aim of this study was to identify the morphological and functional characteristics of quadricuspid aortic valves (QAV) on cardiac computed tomography (CCT). Materials and Methods We retrospectively enrolled 11 patients with QAV. All patients underwent CCT and transthoracic echocardiography (TTE), and 7 patients underwent cardiovascular magnetic resonance (CMR). The presence and classification of QAV assessed by CCT was compared with that of TTE and intraoperative findings. The regurgitant orifice area (ROA) measured by CCT was compared with severity of aortic regurgitation (AR) by TTE and the regurgitant fraction (RF) by CMR. Results All of the patients had AR; 9 had pure AR, 1 had combined aortic stenosis and regurgitation, and 1 had combined subaortic stenosis and regurgitation. Two patients had a subaortic fibrotic membrane and 1 of them showed a subaortic stenosis. One QAV was misdiagnosed as tricuspid aortic valve on TTE. In accordance with the Hurwitz and Robert's classification, consensus was reached on the QAV classification between the CCT and TTE findings in 7 of 10 patients. The patients were classified as type A (n = 1), type B (n = 3), type C (n = 1), type D (n = 4), and type F (n = 2) on CCT. A very high correlation existed between ROA by CCT and RF by CMR (r = 0.99) but a good correlation existed between ROA by CCT and regurgitant severity by TTE (r = 0.62). Conclusion Cardiac computed tomography provides comprehensive anatomical and functional information about the QAV. PMID:27390538

  8. Development and clinical study of mobile 12-lead electrocardiography based on cloud computing for cardiac emergency.

    PubMed

    Fujita, Hideo; Uchimura, Yuji; Waki, Kayo; Omae, Koji; Takeuchi, Ichiro; Ohe, Kazuhiko

    2013-01-01

    To improve emergency services for accurate diagnosis of cardiac emergency, we developed a low-cost new mobile electrocardiography system "Cloud Cardiology®" based upon cloud computing for prehospital diagnosis. This comprises a compact 12-lead ECG unit equipped with Bluetooth and Android Smartphone with an application for transmission. Cloud server enables us to share ECG simultaneously inside and outside the hospital. We evaluated the clinical effectiveness by conducting a clinical trial with historical comparison to evaluate this system in a rapid response car in the real emergency service settings. We found that this system has an ability to shorten the onset to balloon time of patients with acute myocardial infarction, resulting in better clinical outcome. Here we propose that cloud-computing based simultaneous data sharing could be powerful solution for emergency service for cardiology, along with its significant clinical outcome.

  9. Decoupled time-marching schemes in computational cardiac electrophysiology and ECG numerical simulation.

    PubMed

    Fernández, Miguel A; Zemzemi, Nejib

    2010-07-01

    This work considers the approximation of the cardiac bidomain equations, either isolated or coupled with the torso, via first order semi-implicit time-marching schemes involving a fully decoupled computation of the unknown fields (ionic state, transmembrane potential, extracellular and torso potentials). For the isolated bidomain system, we show that the Gauss-Seidel and Jacobi like splittings do not compromise energy stability; they simply alter the energy norm. Within the framework of the numerical simulation of electrocardiograms (ECG), these bidomain splittings are combined with an explicit Robin-Robin treatment of the heart-torso coupling conditions. We show that the resulting schemes allow a fully decoupled (energy) stable computation of the heart and torso fields, under an additional hyperbolic-CFL like condition. The accuracy and convergence rate of the considered schemes are investigated numerically with a series of numerical experiments.

  10. Personal computer system for tracking cardiac vulnerability by complex demodulation of the T wave.

    PubMed

    Nearing, B D; Verrier, R L

    1993-05-01

    Complex demodulation of the T wave permits tracking of susceptibility to ventricular fibrillation under the clinically relevant conditions of acute myocardial ischemia and reperfusion. To facilitate the processing and to increase the applicability of the methods, we have developed algorithms and applied mathematical transformations that can be carried out with a personal computer. The program is self-contained and menu driven and transforms the data into a three-dimensional graphic display of magnitude of alternans (mV x ms), time in the cardiac cycle, and duration of the assessment. It is suitable for investigations with diverse experimental procedures such as coronary artery occlusion and release, autonomic interventions, behavioral stress testing, and drug administration. Our methodology may be employed in clinical conditions such as postmyocardial infarction. Prinzmetal's angina, and the long QT syndrome, wherein T wave alternans has been reported in body surface leads. Ultimately, T wave alternans analysis with use of the personal computer system may help guide therapeutic interventions.

  11. The 100 most-cited original articles in cardiac computed tomography: A bibliometric analysis.

    PubMed

    O'Keeffe, Michael E; Hanna, Tarek N; Holmes, Davis; Marais, Olivia; Mohammed, Mohammed F; Clark, Sheldon; McLaughlin, Patrick; Nicolaou, Savvas; Khosa, Faisal

    2016-01-01

    Bibliometric analysis is the application of statistical methods to analyze quantitative data about scientific publications. It can evaluate research performance, author productivity, and manuscript impact. To the best of our knowledge, no bibliometric analysis has focused on cardiac computed tomography (CT). The purpose of this paper was to compile a list of the 100 most-cited articles related to cardiac CT literature using Scopus and Web of Science (WOS). A list of the 100 most-cited articles was compiled by order of citation frequency, as well a list of the top 10 most-cited guideline and review articles and the 20 most-cited articles of the years 2014-2015. The database of 100 most-cited articles was analyzed to identify characteristics of highly cited publications. For each manuscript, the number of authors, study design, size of patient cohort and departmental affiliations were cataloged. The 100 most-cited articles were published from 1990 to 2012, with the majority (53) published between 2005 and 2009. The total number of citations varied from 3354 to 196, and the number of citations per year varied from 9.5 to 129.0 with a median and mean of 30.9 and 38.7, respectively. The majority of publications had a study patients sample size of 200 patients or less. The USA and Germany were the nations with the highest number of frequently cited publications. This bibliometric analysis provides insights on the most-cited articles published on the subject of cardiac CT and calcium volume, thus helping to characterize the field and guide future research.

  12. Recent Advances in Cardiac Computed Tomography: Dual Energy, Spectral and Molecular CT Imaging

    PubMed Central

    Danad, Ibrahim; Fayad, Zahi A.; Willemink, Martin J.; Min, James K.

    2015-01-01

    Computed tomography (CT) evolved into a powerful diagnostic tool and it is impossible to imagine current clinical practice without CT imaging. Due to its widespread availability, ease of clinical application, superb sensitivity for detection of CAD, and non-invasive nature, CT has become a valuable tool within the armamentarium of the cardiologist. In the last few years, numerous technological advances in CT have occurred—including dual energy CT (DECT), spectral CT and CT-based molecular imaging. By harnessing the advances in technology, cardiac CT has advanced beyond the mere evaluation of coronary stenosis to an imaging modality tool that permits accurate plaque characterization, assessment of myocardial perfusion and even probing of molecular processes that are involved in coronary atherosclerosis. Novel innovations in CT contrast agents and pre-clinical spectral CT devices have paved the way for CT-based molecular imaging. PMID:26068288

  13. Epicardial Adipose Tissue Is Associated with Plaque Burden and Composition and Provides Incremental Value for the Prediction of Cardiac Outcome. A Clinical Cardiac Computed Tomography Angiography Study

    PubMed Central

    Gitsioudis, Gitsios; Schmahl, Christina; Missiou, Anna; Voss, Andreas; Schüssler, Alena; Abdel-Aty, Hassan; Buss, Sebastian J.; Mueller, Dirk; Vembar, Mani; Bryant, Mark; Kauczor, Hans-Ulrich; Giannitsis, Evangelos; Katus, Hugo A.; Korosoglou, Grigorios

    2016-01-01

    Objectives We sought to investigate the association of epicardial adipose tissue (eCAT) volume with plaque burden, circulating biomarkers and cardiac outcomes in patients with intermediate risk for coronary artery disease (CAD). Methods and Results 177 consecutive outpatients at intermediate risk for CAD and completed biomarker analysis including high-sensitive Troponin T (hs-TnT) and hs-CRP underwent 256-slice cardiac computed tomography angiography (CCTA) between June 2008 and October 2011. Patients with lumen narrowing ≥50% exhibited significantly higher eCAT volume than patients without any CAD or lumen narrowing <50% (median (interquartile range, IQR): 108 (73–167) cm3 vs. 119 (82–196) cm3, p = 0.04). Multivariate regression analysis demonstrated an independent association eCAT volume with plaque burden by number of lesions (R2 = 0.22, rpartial = 0.29, p = 0.026) and CAD severity by lumen narrowing (R2 = 0.22, rpartial = 0.23, p = 0.038) after adjustment for age, diabetes mellitus, hyperlidipemia, body-mass-index (BMI), hs-CRP and hs-TnT. Univariate Cox proportional hazards regression analysis identified a significant association for both increased eCAT volume and maximal lumen narrowing with all cardiac events. Multivariate Cox proportional hazards regression analysis revealed an independent association of increased eCAT volume with all cardiac events after adjustment for age, >3 risk factors, presence of CAD, hs-CRP and hs-TnT. Conclusion Epicardial adipose tissue volume is independently associated with plaque burden and maximum luminal narrowing by CCTA and may serve as an independent predictor for cardiac outcomes in patients at intermediate risk for CAD. PMID:27187590

  14. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    SciTech Connect

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana

    2013-01-15

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods: Whitaker et al.'s study ['Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,' Opt. Express 16(11), 8150-8173 (2008)] on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization

  15. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    PubMed Central

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana

    2013-01-01

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods:Whitaker ’s study [“Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,” Opt. Express 16(11), 8150–8173 (2008)]10.1364/OE.16.008150 on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by

  16. Computational biomarker pipeline from discovery to clinical implementation: plasma proteomic biomarkers for cardiac transplantation.

    PubMed

    Cohen Freue, Gabriela V; Meredith, Anna; Smith, Derek; Bergman, Axel; Sasaki, Mayu; Lam, Karen K Y; Hollander, Zsuzsanna; Opushneva, Nina; Takhar, Mandeep; Lin, David; Wilson-McManus, Janet; Balshaw, Robert; Keown, Paul A; Borchers, Christoph H; McManus, Bruce; Ng, Raymond T; McMaster, W Robert

    2013-04-01

    Recent technical advances in the field of quantitative proteomics have stimulated a large number of biomarker discovery studies of various diseases, providing avenues for new treatments and diagnostics. However, inherent challenges have limited the successful translation of candidate biomarkers into clinical use, thus highlighting the need for a robust analytical methodology to transition from biomarker discovery to clinical implementation. We have developed an end-to-end computational proteomic pipeline for biomarkers studies. At the discovery stage, the pipeline emphasizes different aspects of experimental design, appropriate statistical methodologies, and quality assessment of results. At the validation stage, the pipeline focuses on the migration of the results to a platform appropriate for external validation, and the development of a classifier score based on corroborated protein biomarkers. At the last stage towards clinical implementation, the main aims are to develop and validate an assay suitable for clinical deployment, and to calibrate the biomarker classifier using the developed assay. The proposed pipeline was applied to a biomarker study in cardiac transplantation aimed at developing a minimally invasive clinical test to monitor acute rejection. Starting with an untargeted screening of the human plasma proteome, five candidate biomarker proteins were identified. Rejection-regulated proteins reflect cellular and humoral immune responses, acute phase inflammatory pathways, and lipid metabolism biological processes. A multiplex multiple reaction monitoring mass-spectrometry (MRM-MS) assay was developed for the five candidate biomarkers and validated by enzyme-linked immune-sorbent (ELISA) and immunonephelometric assays (INA). A classifier score based on corroborated proteins demonstrated that the developed MRM-MS assay provides an appropriate methodology for an external validation, which is still in progress. Plasma proteomic biomarkers of acute cardiac

  17. Computational Biomarker Pipeline from Discovery to Clinical Implementation: Plasma Proteomic Biomarkers for Cardiac Transplantation

    PubMed Central

    Cohen Freue, Gabriela V.; Meredith, Anna; Smith, Derek; Bergman, Axel; Sasaki, Mayu; Lam, Karen K. Y.; Hollander, Zsuzsanna; Opushneva, Nina; Takhar, Mandeep; Lin, David; Wilson-McManus, Janet; Balshaw, Robert; Keown, Paul A.; Borchers, Christoph H.; McManus, Bruce; Ng, Raymond T.; McMaster, W. Robert

    2013-01-01

    Recent technical advances in the field of quantitative proteomics have stimulated a large number of biomarker discovery studies of various diseases, providing avenues for new treatments and diagnostics. However, inherent challenges have limited the successful translation of candidate biomarkers into clinical use, thus highlighting the need for a robust analytical methodology to transition from biomarker discovery to clinical implementation. We have developed an end-to-end computational proteomic pipeline for biomarkers studies. At the discovery stage, the pipeline emphasizes different aspects of experimental design, appropriate statistical methodologies, and quality assessment of results. At the validation stage, the pipeline focuses on the migration of the results to a platform appropriate for external validation, and the development of a classifier score based on corroborated protein biomarkers. At the last stage towards clinical implementation, the main aims are to develop and validate an assay suitable for clinical deployment, and to calibrate the biomarker classifier using the developed assay. The proposed pipeline was applied to a biomarker study in cardiac transplantation aimed at developing a minimally invasive clinical test to monitor acute rejection. Starting with an untargeted screening of the human plasma proteome, five candidate biomarker proteins were identified. Rejection-regulated proteins reflect cellular and humoral immune responses, acute phase inflammatory pathways, and lipid metabolism biological processes. A multiplex multiple reaction monitoring mass-spectrometry (MRM-MS) assay was developed for the five candidate biomarkers and validated by enzyme-linked immune-sorbent (ELISA) and immunonephelometric assays (INA). A classifier score based on corroborated proteins demonstrated that the developed MRM-MS assay provides an appropriate methodology for an external validation, which is still in progress. Plasma proteomic biomarkers of acute cardiac

  18. Performance of hybrid programming models for multiscale cardiac simulations: preparing for petascale computation.

    PubMed

    Pope, Bernard J; Fitch, Blake G; Pitman, Michael C; Rice, John J; Reumann, Matthias

    2011-10-01

    Future multiscale and multiphysics models that support research into human disease, translational medical science, and treatment can utilize the power of high-performance computing (HPC) systems. We anticipate that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message-passing processes [e.g., the message-passing interface (MPI)] with multithreading (e.g., OpenMP, Pthreads). The objective of this study is to compare the performance of such hybrid programming models when applied to the simulation of a realistic physiological multiscale model of the heart. Our results show that the hybrid models perform favorably when compared to an implementation using only the MPI and, furthermore, that OpenMP in combination with the MPI provides a satisfactory compromise between performance and code complexity. Having the ability to use threads within MPI processes enables the sophisticated use of all processor cores for both computation and communication phases. Considering that HPC systems in 2012 will have two orders of magnitude more cores than what was used in this study, we believe that faster than real-time multiscale cardiac simulations can be achieved on these systems.

  19. Personalised computational cardiology: Patient-specific modelling in cardiac mechanics and biomaterial injection therapies for myocardial infarction.

    PubMed

    Sack, Kevin L; Davies, Neil H; Guccione, Julius M; Franz, Thomas

    2016-11-01

    Predictive computational modelling in biomedical research offers the potential to integrate diverse data, uncover biological mechanisms that are not easily accessible through experimental methods and expose gaps in knowledge requiring further research. Recent developments in computing and diagnostic technologies have initiated the advancement of computational models in terms of complexity and specificity. Consequently, computational modelling can increasingly be utilised as enabling and complementing modality in the clinic-with medical decisions and interventions being personalised. Myocardial infarction and heart failure are amongst the leading causes of death globally despite optimal modern treatment. The development of novel MI therapies is challenging and may be greatly facilitated through predictive modelling. Here, we review the advances in patient-specific modelling of cardiac mechanics, distinguishing specificity in cardiac geometry, myofibre architecture and mechanical tissue properties. Thereafter, the focus narrows to the mechanics of the infarcted heart and treatment of myocardial infarction with particular attention on intramyocardial biomaterial delivery.

  20. Nonrigid registration-based coronary artery motion correction for cardiac computed tomography

    SciTech Connect

    Bhagalia, Roshni; Pack, Jed D.; Miller, James V.; Iatrou, Maria

    2012-07-15

    Purpose: X-ray computed tomography angiography (CTA) is the modality of choice to noninvasively monitor and diagnose heart disease with coronary artery health and stenosis detection being of particular interest. Reliable, clinically relevant coronary artery imaging mandates high spatiotemporal resolution. However, advances in intrinsic scanner spatial resolution (CT scanners are available which combine nearly 900 detector columns with focal spot oversampling) can be tempered by motion blurring, particularly in patients with unstable heartbeats. As a result, recently numerous methods have been devised to improve coronary CTA imaging. Solutions involving hardware, multisector algorithms, or {beta}-blockers are limited by cost, oversimplifying assumptions about cardiac motion, and populations showing contraindications to drugs, respectively. This work introduces an inexpensive algorithmic solution that retrospectively improves the temporal resolution of coronary CTA without significantly affecting spatial resolution. Methods: Given the goal of ruling out coronary stenosis, the method focuses on 'deblurring' the coronary arteries. The approach makes no assumptions about cardiac motion, can be used on exams acquired at high heart rates (even over 75 beats/min), and draws on a fast and accurate three-dimensional (3D) nonrigid bidirectional labeled point matching approach to estimate the trajectories of the coronary arteries during image acquisition. Motion compensation is achieved by employing a 3D warping of a series of partial reconstructions based on the estimated motion fields. Each of these partial reconstructions is created from data acquired over a short time interval. For brevity, the algorithm 'Subphasic Warp and Add' (SWA) reconstruction. Results: The performance of the new motion estimation-compensation approach was evaluated by a systematic observer study conducted using nine human cardiac CTA exams acquired over a range of average heart rates between 68 and

  1. Decoding Hemodynamics of Large Vessels via Dispersion of Contrast Agent in Cardiac Computed Tomography

    NASA Astrophysics Data System (ADS)

    Eslami, Parastou; Seo, Jung-Hee; Abd, Thura T.; George, Richard; Lardo, Albert C.; Chen, Marcus Y.; Mittal, Rajat

    2015-11-01

    Computed tomography angiography (CTA) has emerged as a powerful tool for the assessment of coronary artery disease and other cardiac conditions. Continuous improvements in the spatial and temporal resolution of CT scanners are revealing details regarding the spatially and temporally varying contrast concentration in the vasculature, that were not evident before. These contrast dispersion patterns offer the possibility of extracting useful information about the hemodynamics from the scans. In the current presentation, we will describe experimental studies carried out with CT compatible phantoms of coronary vessels that provide insights into the effect of imaging artifacts on the observed intracoronary contrast gradients. In addition, we will describe a series of computational fluid dynamics studies that explore the dispersion of contrast through the ascending-descending aorta with particular focus on the effect of the aortic curvature on the dispersion patterns. PE is supported by the NIH Graduate Partnership Program. RM and ACL pending patents in CTA based flow diagnostics and have other significant financial interests in these technologies.

  2. Simulation study of respiratory-induced errors in cardiac positron emission tomography/computed tomography

    SciTech Connect

    Fitzpatrick, Gianna M.; Wells, R. Glenn

    2006-08-15

    Heart disease is a leading killer in Canada and positron emission tomography (PET) provides clinicians with in vivo metabolic information for diagnosing heart disease. Transmission data are usually acquired with {sup 68}Ge, although the advent of PET/CT scanners has made computed tomography (CT) an alternative option. The fast data acquisition of CT compared to PET may cause potential misregistration problems, leading to inaccurate attenuation correction (AC). Using Monte Carlo simulations and an anthropomorphic dynamic computer phantom, this study determines the magnitude and location of respiratory-induced errors in radioactivity uptake measured in cardiac PET/CT. A homogeneous tracer distribution in the heart was considered. The AC was based on (1) a time-averaged attenuation map (2) CT maps from a single phase of the respiratory cycle, and (3) CT maps phase matched to the emission data. Circumferential profiles of the heart uptake were compared and differences of up to 24% were found between the single-phase CT-AC method and the true phantom values. Simulation results were supported by a PET/CT canine study which showed differences of up to 10% in the heart uptake in the lung-heart boundary region when comparing {sup 68}Ge- to CT-based AC with the CT map acquired at end inhalation.

  3. Shifted helical computed tomography to optimize cardiac positron emission tomography-computed tomography coregistration: quantitative improvement and limitations.

    PubMed

    Johnson, Nils P; Pan, Tinsu; Gould, K Lance

    2010-10-01

    Positron emission tomography-computed tomography (PET-CT) uses CT attenuation correction but suffers from misregistration artifacts. However, the quantitative accuracy of helical versus cine CT in the same patient after optimized coregistration by shifting both CT data as needed for each patient is unknown. We studied 293 patients undergoing cardiac perfusion PET-CT using helical CT attenuation correction for comparison to cine CT. Objective, quantitative criteria identified perfusion abnormalities that were associated visually with PET-CT misregistration. Custom software shifted CT data to optimize coregistration with quantitative artifact improvement. The majority (58.1%) of cases with both helical and shifted helical CT data (n  = 93) had artifacts that improved or resolved by software shifting helical CT data. Translation of shifted helical CT was greatest in the x-direction (8.8 ± 3.3 mm) and less in the y- and z-directions (approximately 3.5 mm). The magnitude of differences in quantitative end points was greatest for helical (p  =  .0001, n  =  177 studies), less for shifted helical but significant (p  =  .0001, n  =  93 studies), and least for cine (not significant, n  =  161 studies) CT compared to optimal attenuation correction for each patient. Frequent artifacts owing to attenuation-emission misregistration are substantially corrected by software shifting helical CT scans to achieve proper coregistration that, however, remains on average significantly inferior to cine CT attenuation quantitatively.

  4. Simulation of cardiac electrophysiology on next-generation high-performance computers.

    PubMed

    Bordas, Rafel; Carpentieri, Bruno; Fotia, Giorgio; Maggio, Fabio; Nobes, Ross; Pitt-Francis, Joe; Southern, James

    2009-05-28

    Models of cardiac electrophysiology consist of a system of partial differential equations (PDEs) coupled with a system of ordinary differential equations representing cell membrane dynamics. Current software to solve such models does not provide the required computational speed for practical applications. One reason for this is that little use is made of recent developments in adaptive numerical algorithms for solving systems of PDEs. Studies have suggested that a speedup of up to two orders of magnitude is possible by using adaptive methods. The challenge lies in the efficient implementation of adaptive algorithms on massively parallel computers. The finite-element (FE) method is often used in heart simulators as it can encapsulate the complex geometry and small-scale details of the human heart. An alternative is the spectral element (SE) method, a high-order technique that provides the flexibility and accuracy of FE, but with a reduced number of degrees of freedom. The feasibility of implementing a parallel SE algorithm based on fully unstructured all-hexahedra meshes is discussed. A major computational task is solution of the large algebraic system resulting from FE or SE discretization. Choice of linear solver and preconditioner has a substantial effect on efficiency. A fully parallel implementation based on dynamic partitioning that accounts for load balance, communication and data movement costs is required. Each of these methods must be implemented on next-generation supercomputers in order to realize the necessary speedup. The problems that this may cause, and some of the techniques that are beginning to be developed to overcome these issues, are described.

  5. Computational modeling of inhibition of voltage-gated Ca channels: identification of different effects on uterine and cardiac action potentials

    PubMed Central

    Tong, Wing-Chiu; Ghouri, Iffath; Taggart, Michael J.

    2014-01-01

    The uterus and heart share the important physiological feature whereby contractile activation of the muscle tissue is regulated by the generation of periodic, spontaneous electrical action potentials (APs). Preterm birth arising from premature uterine contractions is a major complication of pregnancy and there remains a need to pursue avenues of research that facilitate the use of drugs, tocolytics, to limit these inappropriate contractions without deleterious actions on cardiac electrical excitation. A novel approach is to make use of mathematical models of uterine and cardiac APs, which incorporate many ionic currents contributing to the AP forms, and test the cell-specific responses to interventions. We have used three such models—of uterine smooth muscle cells (USMC), cardiac sinoatrial node cells (SAN), and ventricular cells—to investigate the relative effects of reducing two important voltage-gated Ca currents—the L-type (ICaL) and T-type (ICaT) Ca currents. Reduction of ICaL (10%) alone, or ICaT (40%) alone, blunted USMC APs with little effect on ventricular APs and only mild effects on SAN activity. Larger reductions in either current further attenuated the USMC APs but with also greater effects on SAN APs. Encouragingly, a combination of ICaL and ICaT reduction did blunt USMC APs as intended with little detriment to APs of either cardiac cell type. Subsequent overlapping maps of ICaL and ICaT inhibition profiles from each model revealed a range of combined reductions of ICaL and ICaT over which an appreciable diminution of USMC APs could be achieved with no deleterious action on cardiac SAN or ventricular APs. This novel approach illustrates the potential for computational biology to inform us of possible uterine and cardiac cell-specific mechanisms. Incorporating such computational approaches in future studies directed at designing new, or repurposing existing, tocolytics will be beneficial for establishing a desired uterine specificity of action

  6. An Interactive Computer Session to Initiate Physical Activity in Sedentary Cardiac Patients: Randomized Controlled Trial

    PubMed Central

    Smith-Ray, Renae L; Dzewaltowski, David A; Glasgow, Russell E; Lee, Rebecca E; Thomas, Deborah SK; Xu, Stanley; Estabrooks, Paul A

    2015-01-01

    Background Physical activity (PA) improves many facets of health. Despite this, the majority of American adults are insufficiently active. Adults who visit a physician complaining of chest pain and related cardiovascular symptoms are often referred for further testing. However, when this testing does not reveal an underlying disease or pathology, patients typically receive no additional standard care services. A PA intervention delivered within the clinic setting may be an effective strategy for improving the health of this population at a time when they may be motivated to take preventive action. Objective Our aim was to determine the effectiveness of a tailored, computer-based, interactive personal action planning session to initiate PA among a group of sedentary cardiac patients following exercise treadmill testing (ETT). Methods This study was part of a larger 2x2 randomized controlled trial to determine the impact of environmental and social-cognitive intervention approaches on the initiation and maintenance of weekly PA for patients post ETT. Participants who were referred to an ETT center but had a negative-test (ie, stress tests results indicated no apparent cardiac issues) were randomized to one of four treatment arms: (1) increased environmental accessibility to PA resources via the provision of a free voucher to a fitness facility in close proximity to their home or workplace (ENV), (2) a tailored social cognitive intervention (SC) using a “5 As”-based (ask, advise, assess, assist, and arrange) personal action planning tool, (3) combined intervention of both ENV and SC approaches (COMBO), or (4) a matched contact nutrition control (CON). Each intervention was delivered using a computer-based interactive session. A general linear model for repeated measures was conducted with change in PA behavior from baseline to 1-month post interactive computer session as the primary outcome. Results Sedentary participants (n=452; 34.7% participation rate) without

  7. Evaluation of static and dynamic perfusion cardiac computed tomography for quantitation and classification tasks.

    PubMed

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R; La Riviere, Patrick J; Alessio, Adam M

    2016-04-01

    Cardiac computed tomography (CT) acquisitions for perfusion assessment can be performed in a dynamic or static mode. Either method may be used for a variety of clinical tasks, including (1) stratifying patients into categories of ischemia and (2) using a quantitative myocardial blood flow (MBF) estimate to evaluate disease severity. In this simulation study, we compare method performance on these classification and quantification tasks for matched radiation dose levels and for different flow states, patient sizes, and injected contrast levels. Under conditions simulated, the dynamic method has low bias in MBF estimates (0 to [Formula: see text]) compared to linearly interpreted static assessment (0.45 to [Formula: see text]), making it more suitable for quantitative estimation. At matched radiation dose levels, receiver operating characteristic analysis demonstrated that the static method, with its high bias but generally lower variance, had superior performance ([Formula: see text]) in stratifying patients, especially for larger patients and lower contrast doses [area under the curve [Formula: see text] to 96 versus 0.86]. We also demonstrate that static assessment with a correctly tuned exponential relationship between the apparent CT number and MBF has superior quantification performance to static assessment with a linear relationship and to dynamic assessment. However, tuning the exponential relationship to the patient and scan characteristics will likely prove challenging. This study demonstrates that the selection and optimization of static or dynamic acquisition modes should depend on the specific clinical task.

  8. A computational model-based validation of Guyton's analysis of cardiac output and venous return curves

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Cohen, R. J.; Mark, R. G.

    2002-01-01

    Guyton developed a popular approach for understanding the factors responsible for cardiac output (CO) regulation in which 1) the heart-lung unit and systemic circulation are independently characterized via CO and venous return (VR) curves, and 2) average CO and right atrial pressure (RAP) of the intact circulation are predicted by graphically intersecting the curves. However, this approach is virtually impossible to verify experimentally. We theoretically evaluated the approach with respect to a nonlinear, computational model of the pulsatile heart and circulation. We developed two sets of open circulation models to generate CO and VR curves, differing by the manner in which average RAP was varied. One set applied constant RAPs, while the other set applied pulsatile RAPs. Accurate prediction of intact, average CO and RAP was achieved only by intersecting the CO and VR curves generated with pulsatile RAPs because of the pulsatility and nonlinearity (e.g., systemic venous collapse) of the intact model. The CO and VR curves generated with pulsatile RAPs were also practically independent. This theoretical study therefore supports the validity of Guyton's graphical analysis.

  9. Sudden Cardiac Risk Stratification with Electrocardiographic Indices - A Review on Computational Processing, Technology Transfer, and Scientific Evidence.

    PubMed

    Gimeno-Blanes, Francisco J; Blanco-Velasco, Manuel; Barquero-Pérez, Óscar; García-Alberola, Arcadi; Rojo-Álvarez, José L

    2016-01-01

    Great effort has been devoted in recent years to the development of sudden cardiac risk predictors as a function of electric cardiac signals, mainly obtained from the electrocardiogram (ECG) analysis. But these prediction techniques are still seldom used in clinical practice, partly due to its limited diagnostic accuracy and to the lack of consensus about the appropriate computational signal processing implementation. This paper addresses a three-fold approach, based on ECG indices, to structure this review on sudden cardiac risk stratification. First, throughout the computational techniques that had been widely proposed for obtaining these indices in technical literature. Second, over the scientific evidence, that although is supported by observational clinical studies, they are not always representative enough. And third, via the limited technology transfer of academy-accepted algorithms, requiring further meditation for future systems. We focus on three families of ECG derived indices which are tackled from the aforementioned viewpoints, namely, heart rate turbulence (HRT), heart rate variability (HRV), and T-wave alternans. In terms of computational algorithms, we still need clearer scientific evidence, standardizing, and benchmarking, siting on advanced algorithms applied over large and representative datasets. New scenarios like electronic health recordings, big data, long-term monitoring, and cloud databases, will eventually open new frameworks to foresee suitable new paradigms in the near future.

  10. Sudden Cardiac Risk Stratification with Electrocardiographic Indices - A Review on Computational Processing, Technology Transfer, and Scientific Evidence

    PubMed Central

    Gimeno-Blanes, Francisco J.; Blanco-Velasco, Manuel; Barquero-Pérez, Óscar; García-Alberola, Arcadi; Rojo-Álvarez, José L.

    2016-01-01

    Great effort has been devoted in recent years to the development of sudden cardiac risk predictors as a function of electric cardiac signals, mainly obtained from the electrocardiogram (ECG) analysis. But these prediction techniques are still seldom used in clinical practice, partly due to its limited diagnostic accuracy and to the lack of consensus about the appropriate computational signal processing implementation. This paper addresses a three-fold approach, based on ECG indices, to structure this review on sudden cardiac risk stratification. First, throughout the computational techniques that had been widely proposed for obtaining these indices in technical literature. Second, over the scientific evidence, that although is supported by observational clinical studies, they are not always representative enough. And third, via the limited technology transfer of academy-accepted algorithms, requiring further meditation for future systems. We focus on three families of ECG derived indices which are tackled from the aforementioned viewpoints, namely, heart rate turbulence (HRT), heart rate variability (HRV), and T-wave alternans. In terms of computational algorithms, we still need clearer scientific evidence, standardizing, and benchmarking, siting on advanced algorithms applied over large and representative datasets. New scenarios like electronic health recordings, big data, long-term monitoring, and cloud databases, will eventually open new frameworks to foresee suitable new paradigms in the near future. PMID:27014083

  11. Organ dose measurements from multiple-detector computed tomography using a commercial dosimetry system and tomographic, physical phantoms

    NASA Astrophysics Data System (ADS)

    Lavoie, Lindsey K.

    The technology of computed tomography (CT) imaging has soared over the last decade with the use of multi-detector CT (MDCT) scanners that are capable of performing studies in a matter of seconds. While the diagnostic information obtained from MDCT imaging is extremely valuable, it is important to ensure that the radiation doses resulting from these studies are at acceptably safe levels. This research project focused on the measurement of organ doses resulting from modern MDCT scanners. A commercially-available dosimetry system was used to measure organ doses. Small dosimeters made of optically-stimulated luminescent (OSL) material were analyzed with a portable OSL reader. Detailed verification of this system was performed. Characteristics studied include energy, scatter, and angular responses; dose linearity, ability to erase the exposed dose and ability to reuse dosimeters multiple times. The results of this verification process were positive. While small correction factors needed to be applied to the dose reported by the OSL reader, these factors were small and expected. Physical, tomographic pediatric and adult phantoms were used to measure organ doses. These phantoms were developed from CT images and are composed of tissue-equivalent materials. Because the adult phantom is comprised of numerous segments, dosimeters were placed in the phantom at several organ locations, and doses to select organs were measured using three clinical protocols: pediatric craniosynostosis, adult brain perfusion and adult cardiac CT angiography (CTA). A wide-beam, 320-slice, volumetric CT scanner and a 64-slice, MDCT scanner were used for organ dose measurements. Doses ranged from 1 to 26 mGy for the pediatric protocol, 1 to 1241 mGy for the brain perfusion protocol, and 2-100 mGy for the cardiac protocol. In most cases, the doses measured on the 64-slice scanner were higher than those on the 320-slice scanner. A methodology to measure organ doses with OSL dosimeters received from CT

  12. Iterative reconstruction in image space (IRIS) in cardiac computed tomography: initial experience.

    PubMed

    Bittencourt, Márcio Sommer; Schmidt, Bernhard; Seltmann, Martin; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner Günther; Achenbach, Stephan

    2011-10-01

    Improvements in image quality in cardiac computed tomography may be achieved through iterative image reconstruction techniques. We evaluated the ability of "Iterative Reconstruction in Image Space" (IRIS) reconstruction to reduce image noise and improve subjective image quality. 55 consecutive patients undergoing coronary CT angiography to rule out coronary artery stenosis were included. A dual source CT system and standard protocols were used. Images were reconstructed using standard filtered back projection and IRIS. Image noise, attenuation within the coronary arteries, contrast, signal to noise and contrast to noise parameters as well as subjective classification of image quality (using a scale with four categories) were evaluated and compared between the two image reconstruction protocols. Subjective image quality (2.8 ± 0.4 in filtered back projection and 2.8 ± 0.4 in iterative reconstruction) and the number of "evaluable" segments per patient 14.0 ± 1.2 in filtered back projection and 14.1 ± 1.1 in iterative reconstruction) were not significant different between the two methods. However iterative reconstruction had a lower image noise (22.6 ± 4.5 HU vs. 28.6 ± 5.1 HU) and higher signal to noise and image to noise ratios in the proximal coronary arteries. IRIS reduces image noise and contrast-to-noise ratio in coronary CT angiography, thus providing potential for reducing radiation exposure.

  13. Dynamic single photon emission computed tomography—basic principles and cardiac applications

    PubMed Central

    Gullberg, Grant T; Reutter, Bryan W; Sitek, Arkadiusz; Maltz, Jonathan S; Budinger, Thomas F

    2011-01-01

    The very nature of nuclear medicine, the visual representation of injected radiopharmaceuticals, implies imaging of dynamic processes such as the uptake and wash-out of radiotracers from body organs. For years, nuclear medicine has been touted as the modality of choice for evaluating function in health and disease. This evaluation is greatly enhanced using single photon emission computed tomography (SPECT), which permits three-dimensional (3D) visualization of tracer distributions in the body. However, to fully realize the potential of the technique requires the imaging of in vivo dynamic processes of flow and metabolism. Tissue motion and deformation must also be addressed. Absolute quantification of these dynamic processes in the body has the potential to improve diagnosis. This paper presents a review of advancements toward the realization of the potential of dynamic SPECT imaging and a brief history of the development of the instrumentation. A major portion of the paper is devoted to the review of special data processing methods that have been developed for extracting kinetics from dynamic cardiac SPECT data acquired using rotating detector heads that move as radiopharmaceuticals exchange between biological compartments. Recent developments in multi-resolution spatiotemporal methods enable one to estimate kinetic parameters of compartment models of dynamic processes using data acquired from a single camera head with slow gantry rotation. The estimation of kinetic parameters directly from projection measurements improves bias and variance over the conventional method of first reconstructing 3D dynamic images, generating time–activity curves from selected regions of interest and then estimating the kinetic parameters from the generated time–activity curves. Although the potential applications of SPECT for imaging dynamic processes have not been fully realized in the clinic, it is hoped that this review illuminates the potential of SPECT for dynamic imaging

  14. Whole body computed tomographic characteristics of skeletal and cardiac muscular metastatic neoplasia in dogs and cats.

    PubMed

    Vignoli, Massimo; Terragni, Rossella; Rossi, Federica; Frühauf, Lukas; Bacci, Barbara; Ressel, Lorenzo; Capitani, Ombretta; Marconato, Laura

    2013-01-01

    Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT-guided tru-cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty-one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well-demarcated, oval-to-round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.

  15. Myocardial Blood Flow Quantification for Evaluation of Coronary Artery Disease by Positron Emission Tomography, Cardiac Magnetic Resonance Imaging, and Computed Tomography

    PubMed Central

    Waller, Alfonso H.; Blankstein, Ron; Kwong, Raymond Y.; Di Carli, Marcelo F.

    2014-01-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging and computed tomography, and its emerging clinical applications. PMID:24718671

  16. Statistical Metamodeling and Sequential Design of Computer Experiments to Model Glyco-Altered Gating of Sodium Channels in Cardiac Myocytes.

    PubMed

    Du, Dongping; Yang, Hui; Ednie, Andrew R; Bennett, Eric S

    2016-09-01

    Glycan structures account for up to 35% of the mass of cardiac sodium ( Nav ) channels. To question whether and how reduced sialylation affects Nav activity and cardiac electrical signaling, we conducted a series of in vitro experiments on ventricular apex myocytes under two different glycosylation conditions, reduced protein sialylation (ST3Gal4(-/-)) and full glycosylation (control). Although aberrant electrical signaling is observed in reduced sialylation, realizing a better understanding of mechanistic details of pathological variations in INa and AP is difficult without performing in silico studies. However, computer model of Nav channels and cardiac myocytes involves greater levels of complexity, e.g., high-dimensional parameter space, nonlinear and nonconvex equations. Traditional linear and nonlinear optimization methods have encountered many difficulties for model calibration. This paper presents a new statistical metamodeling approach for efficient computer experiments and optimization of Nav models. First, we utilize a fractional factorial design to identify control variables from the large set of model parameters, thereby reducing the dimensionality of parametric space. Further, we develop the Gaussian process model as a surrogate of expensive and time-consuming computer models and then identify the next best design point that yields the maximal probability of improvement. This process iterates until convergence, and the performance is evaluated and validated with real-world experimental data. Experimental results show the proposed algorithm achieves superior performance in modeling the kinetics of Nav channels under a variety of glycosylation conditions. As a result, in silico models provide a better understanding of glyco-altered mechanistic details in state transitions and distributions of Nav channels. Notably, ST3Gal4(-/-) myocytes are shown to have higher probabilities accumulated in intermediate inactivation during the repolarization and yield a

  17. A graph theoretic approach for computing 3D+time biventricular cardiac strain from tagged MRI data.

    PubMed

    Li, Ming; Gupta, Himanshu; Lloyd, Steven G; Dell'Italia, Louis J; Denney, Thomas S

    2017-01-01

    Tagged magnetic resonance imaging (tMRI) is a well-established method for evaluating regional mechanical function of the heart. Many techniques have been developed to compute 2D or 3D cardiac deformation and strain from tMRI images. In this paper, we present a new method for measuring 3D plus time biventricular myocardial strain from tMRI data. The method is composed of two parts. First, we use a Gabor filter bank to extract tag points along tag lines. Second, each tag point is classified to one of a set of indexed reference tag lines using a point classification with graph cuts (PCGC) algorithm and a motion compensation technique. 3D biventricular deformation and strain is computed at each image time frame from the classified tag points using a previously published finite difference method. The strain computation is fully automatic after myocardial contours are defined near end-diastole and end-systole. An in-vivo dataset composed of 30 human imaging studies with a range of pathologies was used for validation. Strains computed with the PCGC method with no manual corrections were compared to strains computed from both manually placed tag points and a manually-corrected unwrapped phase method. A typical cardiac imaging study with 10 short-axis slices and 6 long-axis slices required 30 min for contouring followed by 44 min of automated processing. The results demonstrate that the proposed method can reconstruct accurate 3D plus time cardiac strain maps with minimal user intervention.

  18. Cardiac catheterization

    MedlinePlus

    Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization; CAD - cardiac catheterization; Coronary artery disease - cardiac catheterization; Heart valve - cardiac catheterization; Heart failure - ...

  19. Practical considerations for optimizing cardiac computed tomography protocols for comprehensive acquisition prior to transcatheter aortic valve replacement.

    PubMed

    Khalique, Omar K; Pulerwitz, Todd C; Halliburton, Sandra S; Kodali, Susheel K; Hahn, Rebecca T; Nazif, Tamim M; Vahl, Torsten P; George, Isaac; Leon, Martin B; D'Souza, Belinda; Einstein, Andrew J

    2016-01-01

    Transcatheter aortic valve replacement (TAVR) is performed frequently in patients with severe, symptomatic aortic stenosis who are at high risk or inoperable for open surgical aortic valve replacement. Computed tomography angiography (CTA) has become the gold standard imaging modality for pre-TAVR cardiac anatomic and vascular access assessment. Traditionally, cardiac CTA has been most frequently used for assessment of coronary artery stenosis, and scanning protocols have generally been tailored for this purpose. Pre-TAVR CTA has different goals than coronary CTA and the high prevalence of chronic kidney disease in the TAVR patient population creates a particular need to optimize protocols for a reduction in iodinated contrast volume. This document reviews details which allow the physician to tailor CTA examinations to maximize image quality and minimize harm, while factoring in multiple patient and scanner variables which must be considered in customizing a pre-TAVR protocol.

  20. Computational Modeling of Open-Irrigated Electrodes for Radiofrequency Cardiac Ablation Including Blood Motion-Saline Flow Interaction

    PubMed Central

    González-Suárez, Ana; Berjano, Enrique; Guerra, Jose M.; Gerardo-Giorda, Luca

    2016-01-01

    Radiofrequency catheter ablation (RFCA) is a routine treatment for cardiac arrhythmias. During RFCA, the electrode-tissue interface temperature should be kept below 80°C to avoid thrombus formation. Open-irrigated electrodes facilitate power delivery while keeping low temperatures around the catheter. No computational model of an open-irrigated electrode in endocardial RFCA accounting for both the saline irrigation flow and the blood motion in the cardiac chamber has been proposed yet. We present the first computational model including both effects at once. The model has been validated against existing experimental results. Computational results showed that the surface lesion width and blood temperature are affected by both the electrode design and the irrigation flow rate. Smaller surface lesion widths and blood temperatures are obtained with higher irrigation flow rate, while the lesion depth is not affected by changing the irrigation flow rate. Larger lesions are obtained with increasing power and the electrode-tissue contact. Also, larger lesions are obtained when electrode is placed horizontally. Overall, the computational findings are in close agreement with previous experimental results providing an excellent tool for future catheter research. PMID:26938638

  1. Similarity enhancement for automatic segmentation of cardiac structures in computed tomography volumes

    PubMed Central

    Vera, Miguel; Bravo, Antonio; Garreau, Mireille; Medina, Rubén

    2011-01-01

    The aim of this research is proposing a 3–D similarity enhancement technique useful for improving the segmentation of cardiac structures in Multi-Slice Computerized Tomography (MSCT) volumes. The similarity enhancement is obtained by subtracting the intensity of the current voxel and the gray levels of their adjacent voxels in two volumes resulting after preprocessing. Such volumes are: a.- a volume obtained after applying a Gaussian distribution and a morphological top-hat filter to the input and b.- a smoothed volume generated by processing the input with an average filter. Then, the similarity volume is used as input to a region growing algorithm. This algorithm is applied to extract the shape of cardiac structures, such as left and right ventricles, in MSCT volumes. Qualitative and quantitative results show the good performance of the proposed approach for discrimination of cardiac cavities. PMID:22256220

  2. Good visibility of TITAN-2 coronary stents demonstrable on cardiac computer tomographic angiography: a report of 2 cases.

    PubMed

    Ong, Paul Jau; Jau, Ong Paul; Ho, Hee Hwa; Hwa, Ho Hee; Jafary, Fahim Haider; Haider, Jafary Fahim; Loh, Kwok Kong; Kong, Loh Kwok; Ooi, Yau Wei; Wei, Ooi Yau; Wong, Chun Pong; Pong, Wong Chun; Foo, David; David, Foo

    2011-09-01

    Numerous studies have sought to assess stent patency by cardiac computer tomographic angiography (CCTA) in comparison with invasive coronary angiography in patients who had undergone percutaneous coronary stenting. Even with newer generation scanners, CCTA has been of limited value in the assessment of the revascularized patient. The main reason being blooming artifact from metallic stents often obscures stent luminal dimension, making the stented segment unassessable. We report on a novel finding of good visibility of TITAN-2 coronary stents demonstrable on CCTA for 2 patients and discuss the possible mechanism and potential implications of this observation.

  3. Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

    PubMed Central

    Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

    2014-01-01

    In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

  4. High frequency stimulation of cardiac myocytes: A theoretical and computational study

    NASA Astrophysics Data System (ADS)

    Weinberg, Seth H.

    2014-12-01

    High-frequency stimulation (HFS) has recently been identified as a novel approach for terminating life-threatening cardiac arrhythmias. HFS elevates myocyte membrane potential and blocks electrical conduction for the duration of the stimulus. However, low amplitude HFS can induce rapidly firing action potentials, which may reinitiate an arrhythmia. The cellular level mechanisms underlying HFS-induced electrical activity are not well understood. Using a multiscale method, we show that a minimal myocyte model qualitatively reproduces the influence of HFS on cardiac electrical activity. Theoretical analysis and simulations suggest that persistent activation and de-inactivation of ionic currents, in particular a fast inward window current, underlie HFS-induced action potentials and membrane potential elevation, providing hypotheses for future experiments. We derive analytical expressions to describe how HFS modifies ionic current amplitude and gating dynamics. We show how fast inward current parameters influence the parameter regimes for HFS-induced electrical activity, demonstrating how the efficacy of HFS as a therapy for terminating arrhythmias may depend on the presence of pathological conditions or pharmacological treatments. Finally, we demonstrate that HFS terminates cardiac arrhythmias in a one-dimensional ring of cardiac tissue. In this study, we demonstrate a novel approach to characterize the influence of HFS on ionic current gating dynamics, provide new insight into HFS of the myocardium, and suggest mechanisms underlying HFS-induced electrical activity.

  5. High frequency stimulation of cardiac myocytes: a theoretical and computational study.

    PubMed

    Weinberg, Seth H

    2014-12-01

    High-frequency stimulation (HFS) has recently been identified as a novel approach for terminating life-threatening cardiac arrhythmias. HFS elevates myocyte membrane potential and blocks electrical conduction for the duration of the stimulus. However, low amplitude HFS can induce rapidly firing action potentials, which may reinitiate an arrhythmia. The cellular level mechanisms underlying HFS-induced electrical activity are not well understood. Using a multiscale method, we show that a minimal myocyte model qualitatively reproduces the influence of HFS on cardiac electrical activity. Theoretical analysis and simulations suggest that persistent activation and de-inactivation of ionic currents, in particular a fast inward window current, underlie HFS-induced action potentials and membrane potential elevation, providing hypotheses for future experiments. We derive analytical expressions to describe how HFS modifies ionic current amplitude and gating dynamics. We show how fast inward current parameters influence the parameter regimes for HFS-induced electrical activity, demonstrating how the efficacy of HFS as a therapy for terminating arrhythmias may depend on the presence of pathological conditions or pharmacological treatments. Finally, we demonstrate that HFS terminates cardiac arrhythmias in a one-dimensional ring of cardiac tissue. In this study, we demonstrate a novel approach to characterize the influence of HFS on ionic current gating dynamics, provide new insight into HFS of the myocardium, and suggest mechanisms underlying HFS-induced electrical activity.

  6. Little impact of tsunami-stricken nuclear accident on awareness of radiation dose of cardiac computed tomography: A questionnaire study

    PubMed Central

    2013-01-01

    Background With the increased use of cardiac computed tomography (CT), radiation dose remains a major issue, although physicians are trying to reduce the substantial risks associated with use of this diagnostic tool. This study was performed to investigate recognition of the level of radiation exposure from cardiac CT and the differences in the level of awareness of radiation before and after the Fukushima nuclear plant accident. Methods We asked 30 physicians who were undergoing training in internal medicine to determine the equivalent doses of radiation for common radiological examinations when a normal chest X-ray is accepted as one unit; questions about the absolute radiation dose of cardiac CT data were also asked. Results According to the results, 86.6% of respondents believed the exposure to be 1 mSv at most, and 93.3% thought that the exposure was less than that of 100 chest X-rays. This finding indicates that their perceptions were far lower than the actual amounts. Even after the occurrence of such a large nuclear disaster in Fukushima, there were no significant differences in the same subjects’ overall awareness of radiation amounts. Conclusions Even after such a major social issue as the Fukushima nuclear accident, the level of awareness of the accurate radiation amount used in 64-channel multidetector CT (MDCT) by clinical physicians who order this test was not satisfactory. Thus, there is a need for the development of effective continuing education programs to improve awareness of radiation from ionizing radiation devices, including cardiac CT, and emphasis on risk-benefit evaluation based on accurate knowledge during medical training. PMID:23631688

  7. The Incremental Prognostic Value of Cardiac Computed Tomography in Comparison with Single-Photon Emission Computed Tomography in Patients with Suspected Coronary Artery Disease

    PubMed Central

    Lee, Heesun; Yoon, Yeonyee E.; Park, Jun-Bean; Kim, Hack-Lyoung; Park, Hyo Eun; Lee, Seung-Pyo; Kim, Hyung-Kwan; Choi, Su-Yeon; Kim, Yong-Jin; Cho, Goo-Yeong; Zo, Joo-Hee; Sohn, Dae-Won

    2016-01-01

    Background Coronary computed tomographic angiography (CCTA) facilitates comprehensive evaluation of coronary artery disease (CAD), including plaque characterization, and can provide additive diagnostic value to single-photon emission computed tomography (SPECT). However, data regarding the incremental prognostic value of CCTA to SPECT remain sparse. We evaluated the independent and incremental prognostic value of CCTA, as compared with clinical risk factors and SPECT. Materials and methods A total of 1,077 patients with suspected CAD who underwent both SPECT and cardiac CT between 2004 and 2012 were enrolled retrospectively. Presence of reversible or fixed perfusion defect (PD) and summed stress score were evaluated on SPECT. Presence, extent of coronary atherosclerosis and diameter stenosis (DS) were evaluated on CCTA. Plaque composition was categorized as non-calcified, mixed, or calcified according to the volume of calcified component (>130 Hounsfield Units). Patients were followed up for the occurrence of adverse cardiac events including cardiac death, non-fatal myocardial infarction, unstable angina, and late revascularization (>90 days after imaging studies). Results During follow-up (median 23 months), adverse cardiac events were observed in 71 patients (6.6%). When adjusted for clinical risk factors and SPECT findings, the presence of any coronary plaque, any plaque in ≥3 segments, coronary artery calcium score (CACS) ≥400, a plaque ≥50% DS, presence of non-calcified plaque (NCP) or mixed plaque (MP), and NCP/MP in ≥2 segments were independent predictors of adverse cardiac events; however, the presence of calcified plaque (CP) was not. Conventional CCTA findings, including CACS ≥400 and a plaque ≥50% DS, demonstrated incremental prognostic value over clinical risk factors and SPECT (χ² 54.19 to 101.03; p <0.001). Addition of NCP/MP in ≥2 segments resulted in further significantly improved prediction (χ² 101.03 to 113.29; p <0

  8. Cardiac cameras.

    PubMed

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  9. Coronary Computed Tomography Angiography in Combination with Coronary Artery Calcium Scoring for the Preoperative Cardiac Evaluation of Liver Transplant Recipients

    PubMed Central

    Choi, Jae Moon; Kong, Yu-Gyeong

    2017-01-01

    Liver transplantation is the best treatment option for early-stage hepatocellular carcinoma, liver cirrhosis, fulminant liver failure, and end-stage liver diseases. Even though advances in surgical techniques and perioperative care have improved postoperative outcomes, perioperative cardiovascular complications are a leading cause of postoperative morbidity and mortality following liver transplantation. Ischemic coronary artery disease (CAD) and cardiomyopathy are the most common cardiovascular diseases and could be negative predictors of postoperative outcomes in liver transplant recipients. Therefore, comprehensive cardiovascular evaluations are required to assess perioperative risks and prevent concomitant cardiovascular complications that would preclude good outcomes in liver transplant recipients. The two major types of cardiac computed tomography are the coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA). CCTA in combination with the CACS is a validated noninvasive alternative to coronary angiography for diagnosing and grading the severity of CAD. A CACS > 400 is associated with significant CAD and a known important predictor of posttransplant cardiovascular complications in liver transplant recipients. In this review article, we discuss the usefulness, advantages, and disadvantages of CCTA combined with CACS as a noninvasive diagnostic tool for preoperative cardiac evaluation and for maximizing the perioperative outcomes of liver transplant recipients. PMID:28164120

  10. Construction of a computational anatomical model of the peripheral cardiac conduction system.

    PubMed

    Sebastian, Rafael; Zimmerman, Viviana; Romero, Daniel; Frangi, Alejandro F

    2011-12-01

    A methodology is presented here for automatic construction of a ventricular model of the cardiac conduction system (CCS), which is currently a missing block in many multiscale cardiac electromechanic models. It includes the His bundle, left bundle branches, and the peripheral CCS. The algorithm is fundamentally an enhancement of a rule-based method known as the Lindenmayer systems (L-systems). The generative procedure has been divided into three consecutive independent stages, which subsequently build the CCS from proximal to distal sections. Each stage is governed by a set of user parameters together with anatomical and physiological constrains to direct the generation process and adhere to the structural observations derived from histology studies. Several parameters are defined using statistical distributions to introduce stochastic variability in the models. The CCS built with this approach can generate electrical activation sequences with physiological characteristics.

  11. Towards an atrio-ventricular delay optimization assessed by a computer model for cardiac resynchronization therapy

    NASA Astrophysics Data System (ADS)

    Ojeda, David; Le Rolle, Virginie; Tse Ve Koon, Kevin; Thebault, Christophe; Donal, Erwan; Hernández, Alfredo I.

    2013-11-01

    In this paper, lumped-parameter models of the cardiovascular system, the cardiac electrical conduction system and a pacemaker are coupled to generate mitral ow pro les for di erent atrio-ventricular delay (AVD) con gurations, in the context of cardiac resynchronization therapy (CRT). First, we perform a local sensitivity analysis of left ventricular and left atrial parameters on mitral ow characteristics, namely E and A wave amplitude, mitral ow duration, and mitral ow time integral. Additionally, a global sensitivity analysis over all model parameters is presented to screen for the most relevant parameters that a ect the same mitral ow characteristics. Results provide insight on the in uence of left ventricle and atrium in uence on mitral ow pro les. This information will be useful for future parameter estimation of the model that could reproduce the mitral ow pro les and cardiovascular hemodynamics of patients undergoing AVD optimization during CRT.

  12. Relationship between routine multi-detector cardiac computed tomographic angiography prior to reoperative cardiac surgery, length of stay, and hospital charges.

    PubMed

    Goldstein, Matthew A; Roy, Sion K; Hebsur, Shinivas; Maluenda, Gabriel; Weissman, Gaby; Weigold, Guy; Landsman, Marc J; Hill, Peter C; Pita, Francisco; Corso, Paul J; Boyce, Steven W; Pichard, Augusto D; Waksman, Ron; Taylor, Allen J

    2013-03-01

    While multi-detector cardiac computed tomography angiography (MDCCTA) prior to reoperative cardiac surgery (RCS) has been associated with improved clinical outcomes, its impact on hospital charges and length of stay remains unclear. We studied 364 patients undergoing RCS at Washington Hospital Center between 2004 and 2008, including 137 clinically referred for MDCCTA. Baseline demographics, procedural data, and perioperative outcomes were recorded at the time of the procedure. The primary clinical endpoint was the composite of perioperative death, myocardial infarction (MI), stroke, and hemorrhage-related reoperation. Secondary clinical endpoints included surgical procedural variables and the perioperative volume of bleeding and transfusion. Length of stay was determined using the hospital's electronic medical record. Cost data were extracted from the hospital's billing summary. Analysis was performed on individual categories of care, as well as on total hospital charges. Data were compared between subjects with and without MDCCTA, after adjustment for the Society of Thoracic Surgeons score. Baseline characteristics were similar between the two groups. MDCCTA was associated with shorter procedural times, shorter intensive care unit stays, fewer blood transfusions, and less frequent perioperative MI. There was additionally a trend towards a lower incidence of the primary endpoint (17.5 vs. 24.2 %, p = 0.13) primarily due to a lower incidence of perioperative MI (0 vs. 5.7 %, p = 0.002). MDCCTA was also associated with lower median recovery room [$1,325 (1,250-3,302) vs. $3,217 (1,325-5,353) p < 0.001] and nursing charges [$6,335 (3,623-10,478) vs. $6,916 (3,915-14,499) p = 0.03], although operating room charges were higher [$24,100 (22,300-29,700) vs. $23,500 (19,900-27,700) p < 0.05]. Median total charges [$127,000 (95,000-188,000) vs. $123,000 (86,800-226,000) p = 0.77] and length of stay [9 days (6-19) vs. 11 days (7-19), p = 0.21] were similar. Means analysis

  13. Assessment of myocardial delayed enhancement with cardiac computed tomography in cardiomyopathies: a prospective comparison with delayed enhancement cardiac magnetic resonance imaging.

    PubMed

    Lee, Hye-Jeong; Im, Dong Jin; Youn, Jong-Chan; Chang, Suyon; Suh, Young Joo; Hong, Yoo Jin; Kim, Young Jin; Hur, Jin; Choi, Byoung Wook

    2016-11-22

    To evaluate the feasibility of cardiac CT for the evaluation of myocardial delayed enhancement (MDE) in the assessment of patients with cardiomyopathy, compared to cardiac MRI. A total of 37 patients (mean age 54.9 ± 15.7 years, 24 men) who underwent cardiac MRI to evaluate cardiomyopathy were enrolled. Dual-energy ECG-gated cardiac CT was acquired 12 min after contrast injection. Two observers evaluated cardiac MRI and cardiac CT at different kV settings (100, 120 and 140 kV) independently for MDE pattern-classification (patchy, transmural, subendocardial, epicardial and mesocardial), differentiation between ischemic and non-ischemic cardiomyopathy and MDE quantification (percentage MDE). Kappa statics and the intraclass correlation coefficient were used for statistical analysis. Among different kV settings, 100-kV CT showed excellent agreements compared to cardiac MRI for MDE detection (κ = 0.886 and 0.873, respectively), MDE pattern-classification (κ = 0.888 and 0.881, respectively) and differentiation between ischemic and non-ischemic cardiomyopathy (κ = 1.000 and 0.893, respectively) for both Observer 1 and Observer 2. The Bland-Altman plot between MRI and 100-kV CT for the percentage MDE showed a very small bias (-0.15%) with 95% limits of agreement of -7.02 and 6.72. Cardiac CT using 100 kV might be an alternative method to cardiac MRI in the assessment of cardiomyopathy, particularly in patients with contraindications to cardiac MRI.

  14. Cardiac tissue structure. Electric field interactions in polarizing the heart: 3D computer models and applications

    NASA Astrophysics Data System (ADS)

    Entcheva, Emilia

    1998-11-01

    The goal of this research is to investigate the interactions between the cardiac tissue structure and applied electric fields in producing complex polarization patterns. It is hypothesized that the response of the heart in the conditions of strong electric shocks, as those applied in defibrillation, is dominated by mechanisms involving the cardiac muscle structure perceived as a continuum. Analysis is carried out in three-dimensional models of the heart with detailed fiber architecture. Shock-induced transmembrane potentials are calculated using the bidomain model in its finite element implementation. The major new findings of this study can be summarized as follows: (1) The mechanisms of polarization due to cardiac fiber curvature and fiber rotation are elucidated in three-dimensional ellipsoidal hearts of variable geometry; (2) Results are presented showing that the axis of stimulation and the polarization axis on a whole heart level might differ significantly due to geometric and anisotropic factors; (3) Virtual electrode patterns are demonstrated numerically inside the ventricular wall in internal defibrillation conditions. The role of the tissue-bath interface in shaping the shock-induced polarization is revealed; (4) The generation of 3D phase singularity scrolls by shock-induced intramural virtual electrode patterns is proposed as evidence for a possible new mechanism for the failure to defibrillate. The results of this study emphasize the role of unequal anisotropy in the intra- and extracellular domains, as well as the salient fiber architecture characteristics, such as curvature and transmural rotation, in polarizing the myocardium. Experimental support of the above findings was actively sought and found in recent optical mapping studies using voltage-sensitive dyes. If validated in vivo, these findings would significantly enrich the prevailing concepts about the mechanisms of stimulation and defibrillation of the heart.

  15. A collaborative exercise between graduate and undergraduate nursing students using a computer-assisted simulator in a mock cardiac arrest.

    PubMed

    Bruce, Susan A; Scherer, Yvonne K; Curran, Cynthia C; Urschel, Dorothy M; Erdley, Scott; Ball, Lisa S

    2009-01-01

    Faculty at the University at Buffalo designed and implemented a mock cardiac arrest that involved joint participation by both undergraduate and graduate students. Various instruments were developed to evaluate the effectiveness of this teaching modality, including scales that measured pre- and postsimulation knowledge and confidence. Students were also asked to evaluate the strengths and weaknesses of the experience especially regarding teamwork during an emergency situation. Management of the arrest by the graduate students was evaluated using a scale that included competency criteria related to assessment, diagnosis, treatment, and resource management. Undergraduate students' performance was also evaluated. Using paired t-test statistics, postsimulation knowledge scores were significantly higher than presimulation scores (p = .000), while postsimulation confidence scores were not statistically significant (p = .177). Students at both levels reported high satisfaction with the experience and with the opportunity to participate in a simulated cardiac arrest as a member of the health team. The use of a computer-assisted human patient simulator involving different levels of nursing students appears to be an effective teaching method; more investigation into specific outcomes is needed.

  16. Contrast enhanced micro-computed tomography resolves the 3-dimensional morphology of the cardiac conduction system in mammalian hearts.

    PubMed

    Stephenson, Robert S; Boyett, Mark R; Hart, George; Nikolaidou, Theodora; Cai, Xue; Corno, Antonio F; Alphonso, Nelson; Jeffery, Nathan; Jarvis, Jonathan C

    2012-01-01

    The general anatomy of the cardiac conduction system (CCS) has been known for 100 years, but its complex and irregular three-dimensional (3D) geometry is not so well understood. This is largely because the conducting tissue is not distinct from the surrounding tissue by dissection. The best descriptions of its anatomy come from studies based on serial sectioning of samples taken from the appropriate areas of the heart. Low X-ray attenuation has formerly ruled out micro-computed tomography (micro-CT) as a modality to resolve internal structures of soft tissue, but incorporation of iodine, which has a high molecular weight, into those tissues enhances the differential attenuation of X-rays and allows visualisation of fine detail in embryos and skeletal muscle. Here, with the use of a iodine based contrast agent (I(2)KI), we present contrast enhanced micro-CT images of cardiac tissue from rat and rabbit in which the three major subdivisions of the CCS can be differentiated from the surrounding contractile myocardium and visualised in 3D. Structures identified include the sinoatrial node (SAN) and the atrioventricular conduction axis: the penetrating bundle, His bundle, the bundle branches and the Purkinje network. Although the current findings are consistent with existing anatomical representations, the representations shown here offer superior resolution and are the first 3D representations of the CCS within a single intact mammalian heart.

  17. Computational cardiology and risk stratification for sudden cardiac death: one of the grand challenges for cardiology in the 21st century.

    PubMed

    Hill, Adam P; Perry, Matthew D; Abi-Gerges, Najah; Couderc, Jean-Philippe; Fermini, Bernard; Hancox, Jules C; Knollmann, Bjorn C; Mirams, Gary R; Skinner, Jon; Zareba, Wojciech; Vandenberg, Jamie I

    2016-12-01

    Risk stratification in the context of sudden cardiac death has been acknowledged as one of the major challenges facing cardiology for the past four decades. In recent years, the advent of high performance computing has facilitated organ-level simulation of the heart, meaning we can now examine the causes, mechanisms and impact of cardiac dysfunction in silico. As a result, computational cardiology, largely driven by the Physiome project, now stands at the threshold of clinical utility in regards to risk stratification and treatment of patients at risk of sudden cardiac death. In this white paper, we outline a roadmap of what needs to be done to make this translational step, using the relatively well-developed case of acquired or drug-induced long QT syndrome as an exemplar case.

  18. Computational cardiology and risk stratification for sudden cardiac death: one of the grand challenges for cardiology in the 21st century

    PubMed Central

    Perry, Matthew D.; Abi‐Gerges, Najah; Couderc, Jean‐Philippe; Fermini, Bernard; Hancox, Jules C.; Knollmann, Bjorn C.; Mirams, Gary R.; Skinner, Jon; Zareba, Wojciech; Vandenberg, Jamie I.

    2016-01-01

    Abstract Risk stratification in the context of sudden cardiac death has been acknowledged as one of the major challenges facing cardiology for the past four decades. In recent years, the advent of high performance computing has facilitated organ‐level simulation of the heart, meaning we can now examine the causes, mechanisms and impact of cardiac dysfunction in silico. As a result, computational cardiology, largely driven by the Physiome project, now stands at the threshold of clinical utility in regards to risk stratification and treatment of patients at risk of sudden cardiac death. In this white paper, we outline a roadmap of what needs to be done to make this translational step, using the relatively well‐developed case of acquired or drug‐induced long QT syndrome as an exemplar case. PMID:27060987

  19. Experimental and computational studies on complex spiral waves in 2-D cardiac substrates

    NASA Astrophysics Data System (ADS)

    Bursac, Nenad

    2005-03-01

    A variety of chemical and biological nonlinear excitable media including heart tissue can support stable, self-organized waves of activity in a form of rotating single-arm spirals. In the heart tissue, stable single-arm spirals can underlie highly periodic activity such as monomorphic ventricular tachycardia (VT), while unstable spirals that continuously form and break up are shown to underlie aperiodic and lethal heart activity, namely fibrillation. Although fast pacing from a point in the heart is commonly used to terminate VT, it can occasionally yield a transient or stable acceleration of tachicardia rate and/or fibrillation. In this study we tested the effect of rapid point pacing on sustained spiral waves in the uniformly anisotropic cultures of cardiac myocytes. In 15/79 cultures, rapid pacing induced a stable formation of multiple bound spiral waves (a complex spiral) and acceleration of overall excitation rate in the tissue, as assessed by pseudo ECG (pECG). The level of rate acceleration correlated with the number of rotating waves. Further rapid point pacing decelerated, terminated, or further accelerated the complex spiral activity via a change in the number of coexisting rotating waves. The dynamic restitution analysis revealed no alternans in action potential duration in any of the cultures. Stable formation of complex spirals was accomplished only in the cultures that showed relatively broad and steep impulse wavelength and conduction velocity restitutions. A necessary condition for rate acceleration in a medium with monotonic restitution is that the rate of rotation of a single spiral wave is significantly lower than maximum sustainable rate of excitation in the medium. Preliminary data in a homogeneous medium using 3-variable Fenton-Karma (FK) based model of cardiac tissue suggest that decrease of fast inward current (excitability) can shift the spiral rate away from the break point on the restitution curve, enabling a necessary condition for rate

  20. Modeling Cardiac Electrophysiology at the Organ Level in the Peta FLOPS Computing Age

    NASA Astrophysics Data System (ADS)

    Mitchell, Lawrence; Bishop, Martin; Hötzl, Elena; Neic, Aurel; Liebmann, Manfred; Haase, Gundolf; Plank, Gernot

    2010-09-01

    Despite a steep increase in available compute power, in-silico experimentation with highly detailed models of the heart remains to be challenging due to the high computational cost involved. It is hoped that next generation high performance computing (HPC) resources lead to significant reductions in execution times to leverage a new class of in-silico applications. However, peformance gains with these new platforms can only be achieved by engaging a much larger number of compute cores, necessitating strongly scalable numerical techniques. So far strong scalability has been demonstrated only for a moderate number of cores, orders of magnitude below the range required to achieve the desired performance boost. In this study, strong scalability of currently used techniques to solve the bidomain equations is investigated. Benchmark results suggest that scalability is limited to 512-4096 cores within the range of relevant problem sizes even when systems are carefully load-balanced and advanced IO strategies are employed.

  1. Modeling Cardiac Electrophysiology at the Organ Level in the Peta FLOPS Computing Age

    SciTech Connect

    Mitchell, Lawrence; Bishop, Martin; Hoetzl, Elena; Neic, Aurel; Liebmann, Manfred; Haase, Gundolf; Plank, Gernot

    2010-09-30

    Despite a steep increase in available compute power, in-silico experimentation with highly detailed models of the heart remains to be challenging due to the high computational cost involved. It is hoped that next generation high performance computing (HPC) resources lead to significant reductions in execution times to leverage a new class of in-silico applications. However, performance gains with these new platforms can only be achieved by engaging a much larger number of compute cores, necessitating strongly scalable numerical techniques. So far strong scalability has been demonstrated only for a moderate number of cores, orders of magnitude below the range required to achieve the desired performance boost.In this study, strong scalability of currently used techniques to solve the bidomain equations is investigated. Benchmark results suggest that scalability is limited to 512-4096 cores within the range of relevant problem sizes even when systems are carefully load-balanced and advanced IO strategies are employed.

  2. A Computational Model of Reactive Oxygen Species and Redox Balance in Cardiac Mitochondria

    PubMed Central

    Gauthier, Laura D.; Greenstein, Joseph L.; Cortassa, Sonia; O’Rourke, Brian; Winslow, Raimond L.

    2013-01-01

    Elevated levels of reactive oxygen species (ROS) play a critical role in cardiac myocyte signaling in both healthy and diseased cells. Mitochondria represent the predominant cellular source of ROS, specifically the activity of complexes I and III. The model presented here explores the modulation of electron transport chain ROS production for state 3 and state 4 respiration and the role of substrates and respiratory inhibitors. Model simulations show that ROS production from complex III increases exponentially with membrane potential (ΔΨm) when in state 4. Complex I ROS release in the model can occur in the presence of NADH and succinate (reverse electron flow), leading to a highly reduced ubiquinone pool, displaying the highest ROS production flux in state 4. In the presence of ample ROS scavenging, total ROS production is moderate in state 3 and increases substantially under state 4 conditions. The ROS production model was extended by combining it with a minimal model of ROS scavenging. When the mitochondrial redox status was oxidized by increasing the proton permeability of the inner mitochondrial membrane, simulations with the combined model show that ROS levels initially decline as production drops off with decreasing ΔΨm and then increase as scavenging capacity is exhausted. Hence, this mechanistic model of ROS production demonstrates how ROS levels are controlled by mitochondrial redox balance. PMID:23972856

  3. Effect of regional differences in cardiac cellular electrophysiology on the stability of ventricular arrhythmias: a computational study

    NASA Astrophysics Data System (ADS)

    Clayton, Richard H.; Holden, Arun V.

    2003-01-01

    Re-entry is an important mechanism of cardiac arrhythmias. During re-entry a wave of electrical activation repeatedly propagates into recovered tissue, rotating around a rod-like filament. Breakdown of a single re-entrant wave into multiple waves is believed to underlie the transition from ventricular tachycardia to ventricular fibrillation. Several mechanisms of breakup have been identified including the effect of anisotropic conduction in the ventricular wall. Cells in the inner and outer layers of the ventricular wall have different action potential durations (APD), and support re-entrant waves with different periods. The aim of this study was to use a computational approach to study twisting and breakdown in a transmural re-entrant wave spanning these regions, and examine the relative role of this effect and anisotropic conduction. We used a simplified model of action potential conduction in the ventricular wall that we modified so that it supported stable re-entry in an anisotropic model with uniform APD. We first examined the effect of regional differences on breakdown in an isotropic model with transmural differences in APD, and found that twisting of the re-entrant filament resulted in buckling and breakdown during the second cycle of re-entry. We found that breakdown was amplified in the anisotropic model, resulting in complex activation in the region of longest APD. This study shows that regional differences in cardiac electrophysiology are a potentially important mechanism for destabilizing re-entry and may act synergistically with other mechanisms to mediate the transition from ventricular tachycardia to ventricular fibrillation.

  4. Intrinsic Cardiac Autonomic Ganglionated Plexi within Epicardial Fats Modulate the Atrial Substrate Remodeling: Experiences with Atrial Fibrillation Patients Receiving Catheter Ablation

    PubMed Central

    Singhal, Rahul; Lo, Li-Wei; Lin, Yenn-Jiang Lin; Chang, Shih-Lin; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Chiou, Cheun-Wang; Tsao, Hsuan-Ming; Chen, Shih-Ann

    2016-01-01

    Background A recent study reported the close relationship between high dominant frequent (DF) sites [atrial fibrillation (AF) nest] and the intrinsic cardiac autonomic nervous system. The aim of this study was to investigate the correlation between the regional distribution of epicardial fat and the properties of the biatrial substrates in AF patients. Methods We studied 32 patients with paroxysmal (n = 23) and persistent (n = 9) AF. The epicardial fat volume around the left atrium (LA) was evaluated using 64-slice multidetector computed tomography and the topographic distribution of the fat volume was assessed. The biatrial DFs, voltages, and total activation times (TATs) were obtained during sinus rhythm. Results Out of the 8 divided LA regions, a significant linear correlation existed between the LA fat and mean DF values in the right upper anterior LA, left upper anterior LA, right lower anterior LA, right upper posterior LA, left upper posterior LA, and left lower posterior LA. There was no significant correlation between the regional LA fat distribution and regional LA peak-to-peak bipolar voltage and TAT. During a mean follow-up of 17 ± 8 months, 22 of the 32 (69%) patients were free of AF. In the multivariate analysis, only the mean LA DF was found to be a significant predictor of recurrence. Conclusions There was a close association between the regional distribution of the LA epicardial fat and the atrial substrate manifesting high frequency during sinus rhythm (AF nest). Those nests were related to ablation outcome. Hence, epicardial fat may play a significant role in atrial substrate remodeling and thereby in the pathogenesis and maintenance of AF. PMID:27122948

  5. Toward an Integrative Computational Model of the Guinea Pig Cardiac Myocyte

    PubMed Central

    Gauthier, Laura Doyle; Greenstein, Joseph L.; Winslow, Raimond L.

    2012-01-01

    The local control theory of excitation-contraction (EC) coupling asserts that regulation of calcium (Ca2+) release occurs at the nanodomain level, where openings of single L-type Ca2+ channels (LCCs) trigger openings of small clusters of ryanodine receptors (RyRs) co-localized within the dyad. A consequence of local control is that the whole-cell Ca2+ transient is a smooth continuous function of influx of Ca2+ through LCCs. While this so-called graded release property has been known for some time, its functional importance to the integrated behavior of the cardiac ventricular myocyte has not been fully appreciated. We previously formulated a biophysically based model, in which LCCs and RyRs interact via a coarse-grained representation of the dyadic space. The model captures key features of local control using a low-dimensional system of ordinary differential equations. Voltage-dependent gain and graded Ca2+ release are emergent properties of this model by virtue of the fact that model formulation is closely based on the sub-cellular basis of local control. In this current work, we have incorporated this graded release model into a prior model of guinea pig ventricular myocyte electrophysiology, metabolism, and isometric force production. The resulting integrative model predicts the experimentally observed causal relationship between action potential (AP) shape and timing of Ca2+ and force transients, a relationship that is not explained by models lacking the graded release property. Model results suggest that even relatively subtle changes in AP morphology that may result, for example, from remodeling of membrane transporter expression in disease or spatial variation in cell properties, may have major impact on the temporal waveform of Ca2+ transients, thus influencing tissue level electromechanical function. PMID:22783206

  6. Cardiac computed tomography for the evaluation of the acute chest pain syndrome: state of the art.

    PubMed

    Schlett, Christopher L; Hoffmann, Udo; Geisler, Tobias; Nikolaou, Konstantin; Bamberg, Fabian

    2015-03-01

    Coronary computed tomography angiography (CCTA) is recommended for the triage of acute chest pain in patients with a low-to-intermediate likelihood for acute coronary syndrome. Absence of coronary artery disease (CAD) confirmed by CCTA allows rapid emergency department discharge. This article shows that CCTA-based triage is as safe as traditional triage, reduces the hospital length of stay, and may provide cost-effective or even cost-saving care.

  7. Relation of aortic valve calcium detected by cardiac computed tomography to all-cause mortality.

    PubMed

    Blaha, Michael J; Budoff, Matthew J; Rivera, Juan J; Khan, Atif N; Santos, Raul D; Shaw, Leslee J; Raggi, Paolo; Berman, Daniel; Rumberger, John A; Blumenthal, Roger S; Nasir, Khurram

    2010-12-15

    Aortic valve calcium (AVC) can be quantified on the same computed tomographic scan as coronary artery calcium (CAC). Although CAC is an established predictor of cardiovascular events, limited evidence is available for an independent predictive value for AVC. We studied a cohort of 8,401 asymptomatic subjects (mean age 53 ± 10 years, 69% men), who were free of known coronary heart disease and were undergoing electron beam computed tomography for assessment of subclinical atherosclerosis. The patients were followed for a median of 5 years (range 1 to 7) for the occurrence of mortality from any cause. Multivariate Cox regression models were developed to predict all-cause mortality according to the presence of AVC. A total of 517 patients (6%) had AVC on electron beam computed tomography. During follow-up, 124 patients died (1.5%), for an overall survival rate of 96.1% and 98.7% for those with and without AVC, respectively (hazard ratio 3.39, 95% confidence interval 2.09 to 5.49). After adjustment for age, gender, hypertension, dyslipidemia, diabetes mellitus, smoking, and a family history of premature coronary heart disease, AVC remained a significant predictor of mortality (hazard ratio 1.82, 95% confidence interval 1.11 to 2.98). Likelihood ratio chi-square statistics demonstrated that the addition of AVC contributed significantly to the prediction of mortality in a model adjusted for traditional risk factors (chi-square = 5.03, p = 0.03) as well as traditional risk factors plus the presence of CAC (chi-square = 3.58, p = 0.05). In conclusion, AVC was associated with increased all-cause mortality, independent of the traditional risk factors and the presence of CAC.

  8. Identification of Cardiac and Aortic Injuries in Trauma with Multi-detector Computed Tomography.

    PubMed

    Shergill, Arvind K; Maraj, Tishan; Barszczyk, Mark S; Cheung, Helen; Singh, Navneet; Zavodni, Anna E

    2015-01-01

    Blunt and penetrating cardiovascular (CV) injuries are associated with a high morbidity and mortality. Rapid detection of these injuries in trauma is critical for patient survival. The advent of multi-detector computed tomography (MDCT) has led to increased detection of CV injuries during rapid comprehensive scanning of stabilized major trauma patients. MDCT has the ability to acquire images with a higher temporal and spatial resolution, as well as the capability to create multiplanar reformats. This pictorial review illustrates several common and life-threatening traumatic CV injuries from a regional trauma center.

  9. Identification of Cardiac and Aortic Injuries in Trauma with Multi-detector Computed Tomography

    PubMed Central

    Shergill, Arvind K; Maraj, Tishan; Barszczyk, Mark S; Cheung, Helen; Singh, Navneet; Zavodni, Anna E

    2015-01-01

    Blunt and penetrating cardiovascular (CV) injuries are associated with a high morbidity and mortality. Rapid detection of these injuries in trauma is critical for patient survival. The advent of multi-detector computed tomography (MDCT) has led to increased detection of CV injuries during rapid comprehensive scanning of stabilized major trauma patients. MDCT has the ability to acquire images with a higher temporal and spatial resolution, as well as the capability to create multiplanar reformats. This pictorial review illustrates several common and life-threatening traumatic CV injuries from a regional trauma center. PMID:26430541

  10. Fetal cardiac ventricular volume, cardiac output, and ejection fraction determined with four-dimensional ultrasound using Spatio-Temporal Image Correlation (STIC) and Virtual Organ Computed-aided AnaLysis (VOCAL™)

    PubMed Central

    Hamill, Neil; Yeo, Lami; Romero, Roberto; Hassan, Sonia S.; Myers, Stephen A.; Mittal, Pooja; Kusanovic, Juan Pedro; Balasubramaniam, Mamtha; Chaiworapongsa, Tinnakorn; Vaisbuch, Edi; Espinoza, Jimmy; Gotsch, Francesca; Goncalves, Luis F.; Lee, Wesley

    2011-01-01

    Objective To quantify fetal cardiovascular parameters with Spatio-Temporal Image Correlation (STIC) and Virtual Organ Computed-aided AnaLysis (VOCAL™) utilizing the sub-feature: “Contour Finder: Trace”. Study Design A cross-sectional study was designed consisting of patients with normal pregnancies between 19 and 40 weeks of gestation. After STIC datasets were acquired, analysis was performed offline (4DView) and the following cardiovascular parameters were evaluated: ventricular volume in end systole and end diastole, stroke volume, cardiac output, and ejection fraction. To account for fetal size, cardiac output was also expressed as a function of head circumference, abdominal circumference, or femoral diaphysis length. Regression models were fitted for each cardiovascular parameter to assess the effect of gestational age and paired comparisons were made between the left and right ventricles. Results 1) Two hundred and seventeen patients were retrospectively identified, of whom 184 had adequate STIC datasets (85% acceptance); 2) ventricular volume, stroke volume, cardiac output, and adjusted cardiac output increased with gestational age; whereas, the ejection fraction decreased as gestation advanced; 3) the right ventricle was larger than the left in both systole (Right: 0.50 ml, IQR: 0.2 – 0.9; vs. Left: 0.27 ml, IQR: 0.1 – 0.5; p<0.001) and diastole (Right: 1.20 ml, IQR: 0.7 – 2.2; vs. Left: 1.03 ml, IQR: 0.5 – 1.7; p<0.001); 4) there were no differences between the left and right ventricle with respect to stroke volume, cardiac output, or adjusted cardiac output; and 5) the left ventricular ejection fraction was greater than the right (Left: 72.2%, IQR: 64 – 78; vs. Right: 62.4%, IQR: 56 – 69; p<0.001). Conclusion Fetal echocardiography, utilizing STIC and VOCAL™ with the sub-feature: “Contour Finder: Trace”, allows assessment of fetal cardiovascular parameters. Normal fetal cardiovascular physiology is characterized by ventricular

  11. Right ventricular free wall pacing improves cardiac pump function in severe pulmonary arterial hypertension: a computer simulation analysis.

    PubMed

    Lumens, Joost; Arts, Theo; Broers, Bernard; Boomars, Karin A; van Paassen, Pieter; Prinzen, Frits W; Delhaas, Tammo

    2009-12-01

    In pulmonary arterial hypertension (PAH), duration of myofiber shortening is prolonged in the right ventricular (RV) free wall (RVfw) compared with that in the interventricular septum and left ventricular free wall. This interventricular mechanical asynchrony eventually leads to right heart failure. We investigated by computer simulation whether, in PAH, early RVfw pacing may improve interventricular mechanical synchrony and, hence, cardiac pump function. A mathematical model of the human heart and circulation was used to simulate left ventricular and RV pump mechanics and myofiber mechanics. First, we simulated cardiovascular mechanics of a healthy adult at rest. Size and mass of heart and blood vessels were adapted so that mechanical tissue load was normalized. Second, compensated PAH was simulated by increasing mean pulmonary artery pressure to 32 mmHg while applying load adaptation. Third, decompensated PAH was simulated by increasing mean pulmonary artery pressure further to 79 mmHg without further adaptation. Finally, early RVfw pacing was simulated in severely decompensated PAH. Time courses of circumferential strain in the ventricular walls as simulated were similar to the ones measured in healthy subjects (uniform strain patterns) and in PAH patients (prolonged RVfw shortening). When simulating pacing in decompensated PAH, RV pump function was best upon 40-ms RVfw preexcitation, as evidenced by maximal decrease of RV end-diastolic volume, reduced RVfw myofiber work, and most homogeneous distribution of workload over the ventricular walls. Thus our simulations indicate that, in decompensated PAH, RVfw pacing may improve RV pump function and may homogenize workload over the ventricular walls.

  12. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

    PubMed Central

    van Deel, Elza; Ridwan, Yanto; van Vliet, J. Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  13. Automatic computation of 2D cardiac measurements from B-mode echocardiography

    NASA Astrophysics Data System (ADS)

    Park, JinHyeong; Feng, Shaolei; Zhou, S. Kevin

    2012-03-01

    We propose a robust and fully automatic algorithm which computes the 2D echocardiography measurements recommended by America Society of Echocardiography. The algorithm employs knowledge-based imaging technologies which can learn the expert's knowledge from the training images and expert's annotation. Based on the models constructed from the learning stage, the algorithm searches initial location of the landmark points for the measurements by utilizing heart structure of left ventricle including mitral valve aortic valve. It employs the pseudo anatomic M-mode image generated by accumulating the line images in 2D parasternal long axis view along the time to refine the measurement landmark points. The experiment results with large volume of data show that the algorithm runs fast and is robust comparable to expert.

  14. Propagation of Electrical Excitation in a Ring of Cardiac Cells: A Computer Simulation Study

    NASA Technical Reports Server (NTRS)

    Kogan, B. Y.; Karplus, W. J.; Karpoukhin, M. G.; Roizen, I. M.; Chudin, E.; Qu, Z.

    1996-01-01

    The propagation of electrical excitation in a ring of cells described by the Noble, Beeler-Reuter (BR), Luo-Rudy I (LR I), and third-order simplified (TOS) mathematical models is studied using computer simulation. For each of the models it is shown that after transition from steady-state circulation to quasi-periodicity achieved by shortening the ring length (RL), the action potential duration (APD) restitution curve becomes a double-valued function and is located below the original ( that of an isolated cell) APD restitution curve. The distributions of APD and diastolic interval (DI) along a ring for the entire range of RL corresponding to quasi-periodic oscillations remain periodic with the period slightly different from two RLs. The 'S' shape of the original APD restitution curve determines the appearance of the second steady-state circulation region for short RLs. For all the models and the wide variety of their original APD restitution curves, no transition from quasi-periodicity to chaos was observed.

  15. Genome-wide Computational Analysis Reveals Cardiomyocyte-specific Transcriptional Cis-regulatory Motifs That Enable Efficient Cardiac Gene Therapy

    PubMed Central

    Rincon, Melvin Y; Sarcar, Shilpita; Danso-Abeam, Dina; Keyaerts, Marleen; Matrai, Janka; Samara-Kuko, Ermira; Acosta-Sanchez, Abel; Athanasopoulos, Takis; Dickson, George; Lahoutte, Tony; De Bleser, Pieter; VandenDriessche, Thierry; Chuah, Marinee K

    2015-01-01

    Gene therapy is a promising emerging therapeutic modality for the treatment of cardiovascular diseases and hereditary diseases that afflict the heart. Hence, there is a need to develop robust cardiac-specific expression modules that allow for stable expression of the gene of interest in cardiomyocytes. We therefore explored a new approach based on a genome-wide bioinformatics strategy that revealed novel cardiac-specific cis-acting regulatory modules (CS-CRMs). These transcriptional modules contained evolutionary-conserved clusters of putative transcription factor binding sites that correspond to a “molecular signature” associated with robust gene expression in the heart. We then validated these CS-CRMs in vivo using an adeno-associated viral vector serotype 9 that drives a reporter gene from a quintessential cardiac-specific α-myosin heavy chain promoter. Most de novo designed CS-CRMs resulted in a >10-fold increase in cardiac gene expression. The most robust CRMs enhanced cardiac-specific transcription 70- to 100-fold. Expression was sustained and restricted to cardiomyocytes. We then combined the most potent CS-CRM4 with a synthetic heart and muscle-specific promoter (SPc5-12) and obtained a significant 20-fold increase in cardiac gene expression compared to the cytomegalovirus promoter. This study underscores the potential of rational vector design to improve the robustness of cardiac gene therapy. PMID:25195597

  16. Genome-wide computational analysis reveals cardiomyocyte-specific transcriptional Cis-regulatory motifs that enable efficient cardiac gene therapy.

    PubMed

    Rincon, Melvin Y; Sarcar, Shilpita; Danso-Abeam, Dina; Keyaerts, Marleen; Matrai, Janka; Samara-Kuko, Ermira; Acosta-Sanchez, Abel; Athanasopoulos, Takis; Dickson, George; Lahoutte, Tony; De Bleser, Pieter; VandenDriessche, Thierry; Chuah, Marinee K

    2015-01-01

    Gene therapy is a promising emerging therapeutic modality for the treatment of cardiovascular diseases and hereditary diseases that afflict the heart. Hence, there is a need to develop robust cardiac-specific expression modules that allow for stable expression of the gene of interest in cardiomyocytes. We therefore explored a new approach based on a genome-wide bioinformatics strategy that revealed novel cardiac-specific cis-acting regulatory modules (CS-CRMs). These transcriptional modules contained evolutionary-conserved clusters of putative transcription factor binding sites that correspond to a "molecular signature" associated with robust gene expression in the heart. We then validated these CS-CRMs in vivo using an adeno-associated viral vector serotype 9 that drives a reporter gene from a quintessential cardiac-specific α-myosin heavy chain promoter. Most de novo designed CS-CRMs resulted in a >10-fold increase in cardiac gene expression. The most robust CRMs enhanced cardiac-specific transcription 70- to 100-fold. Expression was sustained and restricted to cardiomyocytes. We then combined the most potent CS-CRM4 with a synthetic heart and muscle-specific promoter (SPc5-12) and obtained a significant 20-fold increase in cardiac gene expression compared to the cytomegalovirus promoter. This study underscores the potential of rational vector design to improve the robustness of cardiac gene therapy.

  17. Curvature Analysis of Cardiac Excitation Wavefronts

    DTIC Science & Technology

    2013-04-01

    computational cardiac-cell network accurately reproduces a particular kind of cardiac arrhythmia , such as ventricular fibrillation. Curvature Analysis of Cardiac...network accurately reproduces a particular kind of cardiac arrhythmia , such as ventricular fibrillation. Index Terms Cardiac excitation waves...isopotentials, Bézier curves, curvature, cardiac arrhythmia and fibrillation Ç 1 INTRODUCTION AN estimated 81,000,000 American adults, more than onein three

  18. Myocardial hypoperfusion detected by cardiac computed tomography in an adult patient with heart failure after classic repair for corrected transposition of the great arteries.

    PubMed

    Okayama, Satoshi; Seno, Ayako; Soeda, Tsunenari; Takami, Yasuhiro; Horii, Manabu; Uemura, Shiro; Saito, Yoshihiko

    2011-08-01

    A 69-year-old male with a history of classic repair for corrected transposition of the great arteries (TGA) arrived at our hospital with dyspnoea upon exertion. Echocardiography revealed severe dilation and diffuse hypokinesis of the systemic ventricle without obvious valvular dysfunction. Cardiac computed tomography (CT) revealed no significant stenosis. However, the morphological right coronary artery (CA) on the left side was unequally distributed to the large systemic ventricle and was mostly obscured, especially on the anterior wall. A low attenuation area in the anterior wall of the systemic ventricle and prominent trabeculations suggested ischaemia or infarction. We considered that chronic myocardial hypoperfusion due to an inadequate coronary arterial supply was one cause of the exacerbated heart failure long after the classic repair. Cardiac CT is useful for evaluating the distribution of the CA and to predict blood supply to the myocardium in corrected TGA.

  19. The Cardiac Atlas Project—an imaging database for computational modeling and statistical atlases of the heart

    PubMed Central

    Fonseca, Carissa G.; Backhaus, Michael; Bluemke, David A.; Britten, Randall D.; Chung, Jae Do; Cowan, Brett R.; Dinov, Ivo D.; Finn, J. Paul; Hunter, Peter J.; Kadish, Alan H.; Lee, Daniel C.; Lima, Joao A. C.; Medrano−Gracia, Pau; Shivkumar, Kalyanam; Suinesiaputra, Avan; Tao, Wenchao; Young, Alistair A.

    2011-01-01

    Motivation: Integrative mathematical and statistical models of cardiac anatomy and physiology can play a vital role in understanding cardiac disease phenotype and planning therapeutic strategies. However, the accuracy and predictive power of such models is dependent upon the breadth and depth of noninvasive imaging datasets. The Cardiac Atlas Project (CAP) has established a large-scale database of cardiac imaging examinations and associated clinical data in order to develop a shareable, web-accessible, structural and functional atlas of the normal and pathological heart for clinical, research and educational purposes. A goal of CAP is to facilitate collaborative statistical analysis of regional heart shape and wall motion and characterize cardiac function among and within population groups. Results: Three main open-source software components were developed: (i) a database with web-interface; (ii) a modeling client for 3D + time visualization and parametric description of shape and motion; and (iii) open data formats for semantic characterization of models and annotations. The database was implemented using a three-tier architecture utilizing MySQL, JBoss and Dcm4chee, in compliance with the DICOM standard to provide compatibility with existing clinical networks and devices. Parts of Dcm4chee were extended to access image specific attributes as search parameters. To date, approximately 3000 de-identified cardiac imaging examinations are available in the database. All software components developed by the CAP are open source and are freely available under the Mozilla Public License Version 1.1 (http://www.mozilla.org/MPL/MPL-1.1.txt). Availability: http://www.cardiacatlas.org Contact: a.young@auckland.ac.nz Supplementary information: Supplementary data are available at Bioinformatics online. PMID:21737439

  20. Cardiac catheterization - discharge

    MedlinePlus

    Catheterization - cardiac - discharge; Heart catheterization - discharge: Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization discharge; CAD - cardiac catheterization discharge; Coronary artery disease - cardiac catheterization ...

  1. Data analysis in cardiac arrhythmias.

    PubMed

    Rodrigo, Miguel; Pedrón-Torecilla, Jorge; Hernández, Ismael; Liberos, Alejandro; Climent, Andreu M; Guillem, María S

    2015-01-01

    Cardiac arrhythmias are an increasingly present in developed countries and represent a major health and economic burden. The occurrence of cardiac arrhythmias is closely linked to the electrical function of the heart. Consequently, the analysis of the electrical signal generated by the heart tissue, either recorded invasively or noninvasively, provides valuable information for the study of cardiac arrhythmias. In this chapter, novel cardiac signal analysis techniques that allow the study and diagnosis of cardiac arrhythmias are described, with emphasis on cardiac mapping which allows for spatiotemporal analysis of cardiac signals.Cardiac mapping can serve as a diagnostic tool by recording cardiac signals either in close contact to the heart tissue or noninvasively from the body surface, and allows the identification of cardiac sites responsible of the development or maintenance of arrhythmias. Cardiac mapping can also be used for research in cardiac arrhythmias in order to understand their mechanisms. For this purpose, both synthetic signals generated by computer simulations and animal experimental models allow for more controlled physiological conditions and complete access to the organ.

  2. Usefulness of 40-slice multidetector row computed tomography to detect coronary disease in patients prior to cardiac valve surgery.

    PubMed

    Pouleur, Anne-Catherine; le Polain de Waroux, Jean-Benoît; Kefer, Joëlle; Pasquet, Agnès; Coche, Emmanuel; Vanoverschelde, Jean-Louis; Gerber, Bernhard L

    2007-12-01

    Preoperative identification of significant coronary artery disease (CAD) in patients prior to valve surgery requires systematic invasive coronary angiography. The purpose of this current prospective study was to evaluate whether exclusion of CAD by multi-detector CT (MDCT) might potentially avoid systematic cardiac catheterization in these patients. Eighty-two patients (53 males, 62 +/- 13 years) scheduled to undergo valve surgery underwent 40-slice MDCT before invasive quantitative coronary angiography (QCA). According to QCA, 15 patients had CAD (5 one-vessel, 6 two-vessel and 4 three-vessel disease). The remaining 67 patients had no CAD. On a per-vessel basis, MDCT correctly identified 27/29 (sensitivity 93%) vessels with and excluded 277/299 vessels (specificity 93%) without CAD. On a per-patient basis, MDCT correctly identified 14/15 patients with (sensitivity 93%) and 60/67 patients without CAD (specificity 90%). Positive and negative predictive values of MDCT were 67% and 98%. Performing invasive angiography only in patients with abnormal MDCT might have avoided QCA in 60/82 (73%). MDCT could be potentially useful in the preoperative evaluation of patients with valve disease. By selecting only those patients with coronary lesions to undergo invasive coronary angiography, it could avoid cardiac catheterization in a large number of patients without CAD.

  3. Dual-enhancement cardiac computed tomography for assessing left atrial thrombus and pulmonary veins before radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Hur, Jin; Pak, Hui-Nam; Kim, Young Jin; Lee, Hye-Jeong; Chang, Hyuk-Jae; Hong, Yoo Jin; Choi, Byoung Wook

    2013-07-15

    Noninvasive imaging that provides anatomic information while excluding intracardiac thrombus would be of significant clinical value for patients referred for catheter ablation of atrial fibrillation (AF). This study assessed the diagnostic performance of a dual-enhancement single-phase cardiac computed tomography (CT) protocol for thrombus and circulatory stasis detection in AF patients before catheter ablation. We studied 101 consecutive symptomatic AF patients (71 men and 30 women; mean age, 61.8 years) who were scheduled to have catheter ablation. All patients had undergone pre-AF ablation CT imaging and transesophageal echocardiography on the same day. CT was performed with prospective electrocardiographic gating, and scanning began 180 seconds after the test bolus. Mean left atrial appendage (LAA)/ascending aorta Hounsfield unit (HU) ratios were measured on CT images. Among the 101 patients, 9 thrombi and 18 spontaneous echo contrasts were detected by transesophageal echocardiography. The overall sensitivity, specificity, positive predictive value, and negative predictive value of CT for the detection of thrombi in the LAA were 89%, 100%, 100%, and 99%, respectively. The mean LAA/ascending aorta HU ratios were significantly different between thrombus and circulatory stasis (0.17 vs 0.33, p = 0.002). Dual-enhancement single-scan cardiac CT is a sensitive modality for detecting and differentiating LAA thrombus and circulatory stasis.

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

    SciTech Connect

    Mory, Cyril; Auvray, Vincent; Zhang, Bo; Grass, Michael; Schäfer, Dirk; Chen, S. James; Carroll, John D.; Rit, Simon; Peyrin, Françoise; Douek, Philippe; Boussel, Loïc

    2014-02-15

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

  5. Animal-to-animal variability in the phasing of the crustacean cardiac motor pattern: an experimental and computational analysis

    PubMed Central

    Williams, Alex H.; Kwiatkowski, Molly A.; Mortimer, Adam L.; Marder, Eve; Zeeman, Mary Lou

    2013-01-01

    The cardiac ganglion (CG) of Homarus americanus is a central pattern generator that consists of two oscillatory groups of neurons: “small cells” (SCs) and “large cells” (LCs). We have shown that SCs and LCs begin their bursts nearly simultaneously but end their bursts at variable phases. This variability contrasts with many other central pattern generator systems in which phase is well maintained. To determine both the consequences of this variability and how CG phasing is controlled, we modeled the CG as a pair of Morris-Lecar oscillators coupled by electrical and excitatory synapses and constructed a database of 15,000 simulated networks using random parameter sets. These simulations, like our experimental results, displayed variable phase relationships, with the bursts beginning together but ending at variable phases. The model suggests that the variable phasing of the pattern has important implications for the functional role of the excitatory synapses. In networks in which the two oscillators had similar duty cycles, the excitatory coupling functioned to increase cycle frequency. In networks with disparate duty cycles, it functioned to decrease network frequency. Overall, we suggest that the phasing of the CG may vary without compromising appropriate motor output and that this variability may critically determine how the network behaves in response to manipulations. PMID:23446690

  6. Animal-to-animal variability in the phasing of the crustacean cardiac motor pattern: an experimental and computational analysis.

    PubMed

    Williams, Alex H; Kwiatkowski, Molly A; Mortimer, Adam L; Marder, Eve; Zeeman, Mary Lou; Dickinson, Patsy S

    2013-05-01

    The cardiac ganglion (CG) of Homarus americanus is a central pattern generator that consists of two oscillatory groups of neurons: "small cells" (SCs) and "large cells" (LCs). We have shown that SCs and LCs begin their bursts nearly simultaneously but end their bursts at variable phases. This variability contrasts with many other central pattern generator systems in which phase is well maintained. To determine both the consequences of this variability and how CG phasing is controlled, we modeled the CG as a pair of Morris-Lecar oscillators coupled by electrical and excitatory synapses and constructed a database of 15,000 simulated networks using random parameter sets. These simulations, like our experimental results, displayed variable phase relationships, with the bursts beginning together but ending at variable phases. The model suggests that the variable phasing of the pattern has important implications for the functional role of the excitatory synapses. In networks in which the two oscillators had similar duty cycles, the excitatory coupling functioned to increase cycle frequency. In networks with disparate duty cycles, it functioned to decrease network frequency. Overall, we suggest that the phasing of the CG may vary without compromising appropriate motor output and that this variability may critically determine how the network behaves in response to manipulations.

  7. Cardiac Sarcoidosis.

    PubMed

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  8. Effects of Cardiac Medications for Patients With Obstructive Coronary Artery Disease by Coronary Computed Tomographic Angiography: Results from the Multicenter CONFIRM Registry

    PubMed Central

    Schulman-Marcus, Joshua; Hartaigh, Bríain ó; Giambrone, Ashley E; Gransar, Heidi; Valenti, Valentina; Berman, Daniel S.; Budoff, Matthew J.; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Chinnaiyan, Kavitha; Chow, Benjamin J. W.; Cury, Ricardo; Delago, Augustin; Hadamitzky, Martin; Hausleiter, Joerg; Feuchtner, Gudrun; Kim, Yong-Jin; Kaufmann, Philipp A.; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison; Min, James K

    2014-01-01

    Objective This study sought to determine the correlation between baseline cardiac medications and cardiovascular outcomes in patients with obstructive coronary artery disease (CAD) diagnosed by coronary computed tomographic angiography (CCTA). Methods 1637 patients (mean age 64.8 ± 10.2 years, 69.6% male) with obstructive CAD from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry were followed over the course of three years. Obstructive CAD was defined as a >50% stenosis in an epicardial vessel. Medications analyzed included statins, aspirin, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs). Using Cox proportional-hazards models, we calculated the hazard ratio (HR) with 95% confidence intervals (95% CIs) for incident major adverse cardiovascular events (MACE), defined as death, acute coronary syndrome, or myocardial infarction. Results At the time of CCTA, 59%, 54%, 40%, and 46% of patients were using statins, aspirin, beta-blockers, and ACE inhibitors or ARBs, respectively. Statins were associated with a 43% (95% CI = 0.38-0.87, p=0.008) lower adjusted risk of MACE. Following adjustment, aspirin, beta-blockers, ACE inhibitors and ARBs did not attenuate the risk of MACE. When restricted to patients with multivessel obstructive CAD, only statins were associated with lower risk of MACE. Conclusion In patients with obstructive CAD by CCTA, the baseline use of statins was associated with improved clinical outcomes. Other cardiac medications—including aspirin, beta-blockers, ACE inhibitors, and ARBs—were not associated with reduced risk of MACE. PMID:25479800

  9. Cardiac septic pulmonary embolism

    PubMed Central

    Song, Xin yu; Li, Shan; Cao, Jian; Xu, Kai; Huang, Hui; Xu, Zuo jun

    2016-01-01

    Abstract Based on the source of the embolus, septic pulmonary embolism (SPE) can be classified as cardiac, peripheral endogenous, or exogenous. Cardiac SPEs are the most common. We conducted a retrospective analysis of 20 patients with cardiac SPE hospitalized between 1991 and 2013 at a Chinese tertiary referral hospital. The study included 14 males and 6 females with a median age of 38.1 years. Fever (100%), cough (95%), hemoptysis (80%), pleuritic chest pain (80%), heart murmur (80%), and moist rales (75%) were common clinical manifestations. Most patients had a predisposing condition: congenital heart disease (8 patients) and an immunocompromised state (5 patients) were the most common. Staphylococcal (8 patients) and Streptococcal species (4 patients) were the most common causative pathogens. Parenchymal opacities, nodules, cavitations, and pleural effusions were the most common manifestations observed via computed tomography (CT). All patients exhibited significant abnormalities by echocardiography, including 15 patients with right-sided vegetations and 4 with double-sided vegetations. All patients received parenteral antimicrobial therapy as an initial treatment. Fourteen patients received cardiac surgery, and all survived. Among the 6 patients who did not undergo surgery, only 1 survived. Most patients in our cardiac SPE cohort had predisposing conditions. Although most exhibited typical clinical manifestations and radiography, they were nonspecific. For suspected cases of SPE, blood culture, echocardiography, and CT pulmonary angiography (CTPA) are important measures to confirm an early diagnosis. Vigorous early therapy, including appropriate antibiotic treatment and timely cardiac surgery to eradicate the infective source, is critical. PMID:27336870

  10. Analysis of cardiac development in the turtle Emys orbicularis (Testudines: Emidydae) using 3-D computer modeling from histological sections.

    PubMed

    Bertens, Laura M F; Richardson, M K; Verbeek, F J

    2010-07-01

    In this article we present a 3-D modeling study of cardiac development in the European pond turtle, Emys orbicularis (of the reptilian order Testudines). The study is aimed at elucidating the embryonic development of the horizontal septum in the ventricle and underscoring the importance of 3-D reconstructions in studying morphogenesis. Turtles possess one common ventricle, partly divided into three cava by a vertical and a horizontal septum, of which the embryonic origins have so far not been described. We used serial sectioning and computerized high-resolution 3-D reconstructions of different developmental stages to create a chronological overview of cardiogenesis, in order to study this process. This has yielded a new understanding of the development of the horizontal septum and (directly related) the looping of the heart tube. This looping is found to be markedly different from that in the human heart, with the turtle having two clear bends in the part of the heart tube leaving the primitive ventricle, as opposed to one in humans. It is this particular looping that is responsible for the formation of the horizontal septum. In addition to our findings on the ventricular septation this study has also yielded new insights into the developmental origins of the pulmonary vein. The 3-D reconstructions were built using our platform TDR-3-D base and enabled us to study the developmental processes in specific parts of the turtle heart separately and in three dimensions, over time. The complete 3-D reconstructions have been made available to the reader via internet using our 3-D model browser application, which allows interactive viewing of the models. The browser application can be found on bio-imaging.liacs.nl/galleries/emysorbicularis/TurtleGallery.html, along with additional images of both models and histological sections and animation sequences of the models. By allowing the reader to view the material in such an interactive way, we hope to make optimal use of the

  11. Current but not past smoking increases the risk of cardiac events: insights from coronary computed tomographic angiography

    PubMed Central

    Nakanishi, Rine; Berman, Daniel S.; Budoff, Matthew J.; Gransar, Heidi; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Cheng, Victor Y.; Chinnaiyan, Kavitha; Chow, Benjamin J.W.; Cury, Ricardo; Delago, Augustin; Hadamitzky, Martin; Hausleiter, Jörg; Feuchtner, Gudrun; Kim, Yong-Jin; Kaufmann, Philipp A.; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison; Min, James K.

    2015-01-01

    Aims We evaluated coronary artery disease (CAD) extent, severity, and major adverse cardiac events (MACEs) in never, past, and current smokers undergoing coronary CT angiography (CCTA). Methods and results We evaluated 9456 patients (57.1 ± 12.3 years, 55.5% male) without known CAD (1588 current smokers; 2183 past smokers who quit ≥3 months before CCTA; and 5685 never smokers). By risk-adjusted Cox proportional-hazards models, we related smoking status to MACE (all-cause death or non-fatal myocardial infarction). We further performed 1:1:1 propensity matching for 1000 in each group evaluate event risk among individuals with similar age, gender, CAD risk factors, and symptom presentation. During a mean follow-up of 2.8 ± 1.9 years, 297 MACE occurred. Compared with never smokers, current and past smokers had greater atherosclerotic burden including extent of plaque defined as segments with any plaque (2.1 ± 2.8 vs. 2.6 ± 3.2 vs. 3.1 ± 3.3, P < 0.0001) and prevalence of obstructive CAD [1-vessel disease (VD): 10.6% vs. 14.9% vs. 15.2%, P < 0.001; 2-VD: 4.4% vs. 6.1% vs. 6.2%, P = 0.001; 3-VD: 3.1% vs. 5.2% vs. 4.3%, P < 0.001]. Compared with never smokers, current smokers experienced higher MACE risk [hazard ratio (HR) 1.9, 95% confidence interval (CI) 1.4–2.6, P < 0.001], while past smokers did not (HR 1.2, 95% CI 0.8–1.6, P = 0.35). Among matched individuals, current smokers had higher MACE risk (HR 2.6, 95% CI 1.6–4.2, P < 0.001), while past smokers did not (HR 1.3, 95% CI 0.7–2.4, P = 0.39). Similar findings were observed for risk of all-cause death. Conclusion Among patients without known CAD undergoing CCTA, current and past smokers had increased burden of atherosclerosis compared with never smokers; however, risk of MACE was heightened only in current smokers. PMID:25666322

  12. Artificial intelligence in medicine and cardiac imaging: harnessing big data and advanced computing to provide personalized medical diagnosis and treatment.

    PubMed

    Dilsizian, Steven E; Siegel, Eliot L

    2014-01-01

    Although advances in information technology in the past decade have come in quantum leaps in nearly every aspect of our lives, they seem to be coming at a slower pace in the field of medicine. However, the implementation of electronic health records (EHR) in hospitals is increasing rapidly, accelerated by the meaningful use initiatives associated with the Center for Medicare & Medicaid Services EHR Incentive Programs. The transition to electronic medical records and availability of patient data has been associated with increases in the volume and complexity of patient information, as well as an increase in medical alerts, with resulting "alert fatigue" and increased expectations for rapid and accurate diagnosis and treatment. Unfortunately, these increased demands on health care providers create greater risk for diagnostic and therapeutic errors. In the near future, artificial intelligence (AI)/machine learning will likely assist physicians with differential diagnosis of disease, treatment options suggestions, and recommendations, and, in the case of medical imaging, with cues in image interpretation. Mining and advanced analysis of "big data" in health care provide the potential not only to perform "in silico" research but also to provide "real time" diagnostic and (potentially) therapeutic recommendations based on empirical data. "On demand" access to high-performance computing and large health care databases will support and sustain our ability to achieve personalized medicine. The IBM Jeopardy! Challenge, which pitted the best all-time human players against the Watson computer, captured the imagination of millions of people across the world and demonstrated the potential to apply AI approaches to a wide variety of subject matter, including medicine. The combination of AI, big data, and massively parallel computing offers the potential to create a revolutionary way of practicing evidence-based, personalized medicine.

  13. Towards computational modeling of excitation-contraction coupling in cardiac myocytes: reconstruction of structures and proteins from confocal imaging.

    PubMed

    Sachse, Frank B; Savio-Galimberti, Eleonora; Goldhaber, Joshua I; Bridge, John H B

    2009-01-01

    Computational models of excitation-contraction (EC) coupling in myocytes are valuable tools for studying the signaling cascade that transduces transmembrane voltage into mechanical responses. A key component of these models is the appropriate description of structures involved in EC coupling, such as the sarcolemma and ion channels. This study aims at developing an approach for spatial reconstruction of these structures. We exemplified our approach by reconstructing clusters of ryanodine receptors (RyRs) together with the sarcolemma of rabbit ventricular myocytes. The reconstructions were based on dual labeling and three-dimensional (3D) confocal imaging of segments of fixed and permeabilized myocytes lying flat or on end. The imaging led to 3D stacks of cross-sections through myocytes. Methods of digital image processing were applied to deconvolve, filter and segment these stacks. Finally, we created point meshes representing RyR distributions together with volume and surface meshes of the sarcolemma. We suggest that these meshes are suitable for computational studies of structure-function relationships in EC coupling. We propose that this approach can be extended to reconstruct other structures and proteins involved in EC coupling.

  14. A multiscale computational model of spatially resolved calcium cycling in cardiac myocytes: from detailed cleft dynamics to the whole cell concentration profiles

    PubMed Central

    Vierheller, Janine; Neubert, Wilhelm; Falcke, Martin; Gilbert, Stephen H.; Chamakuri, Nagaiah

    2015-01-01

    Mathematical modeling of excitation-contraction coupling (ECC) in ventricular cardiac myocytes is a multiscale problem, and it is therefore difficult to develop spatially detailed simulation tools. ECC involves gradients on the length scale of 100 nm in dyadic spaces and concentration profiles along the 100 μm of the whole cell, as well as the sub-millisecond time scale of local concentration changes and the change of lumenal Ca2+ content within tens of seconds. Our concept for a multiscale mathematical model of Ca2+ -induced Ca2+ release (CICR) and whole cardiomyocyte electrophysiology incorporates stochastic simulation of individual LC- and RyR-channels, spatially detailed concentration dynamics in dyadic clefts, rabbit membrane potential dynamics, and a system of partial differential equations for myoplasmic and lumenal free Ca2+ and Ca2+-binding molecules in the bulk of the cell. We developed a novel computational approach to resolve the concentration gradients from dyadic space to cell level by using a quasistatic approximation within the dyad and finite element methods for integrating the partial differential equations. We show whole cell Ca2+-concentration profiles using three previously published RyR-channel Markov schemes. PMID:26441674

  15. Cardiac Cephalgia

    PubMed Central

    Wassef, Nancy; Ali, Ali Turab; Katsanevaki, Alexia-Zacharoula; Nishtar, Salman

    2014-01-01

    Although most of the patients presenting with ischemic heart disease have chest pains, there are other rare presenting symptoms like cardiac cephalgia. In this report, we present a case of acute coronary syndrome with an only presentation of exertional headache. It was postulated as acute presentation of coronary artery disease, due to previous history of similar presentation associated with some chest pains with previous left coronary artery stenting. We present an unusual case with cardiac cephalgia in a young patient under the age of 50 which was not reported at that age before. There are four suggested mechanisms for this cardiac presentation. PMID:28352454

  16. Cardiac radiology: centenary review.

    PubMed

    de Roos, Albert; Higgins, Charles B

    2014-11-01

    During the past century, cardiac imaging technologies have revolutionized the diagnosis and treatment of acquired and congenital heart disease. Many important contributions to the field of cardiac imaging were initially reported in Radiology. The field developed from the early stages of cardiac imaging, including the use of coronary x-ray angiography and roentgen kymography, to nowadays the widely used echocardiographic, nuclear medicine, cardiac computed tomographic (CT), and magnetic resonance (MR) applications. It is surprising how many of these techniques were not recognized for their potential during their early inception. Some techniques were described in the literature but required many years to enter the clinical arena and presently continue to expand in terms of clinical application. The application of various CT and MR contrast agents for the diagnosis of myocardial ischemia is a case in point, as the utility of contrast agents continues to expand the noninvasive characterization of myocardium. The history of cardiac imaging has included a continuous process of advances in our understanding of the anatomy and physiology of the cardiovascular system, along with advances in imaging technology that continue to the present day.

  17. Nuclear cardiac

    SciTech Connect

    Slutsky, R.; Ashburn, W.L.

    1982-01-01

    The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques. (KRM)

  18. Prevalence of coronary artery ectasia in older adults and the relationship with epicardial fat volume by cardiac computed tomography angiography

    PubMed Central

    Yang, Jun-Jie; Yang, Xia; Chen, Zhi-Ye; Wang, Qi; He, Bai; Du, Luo-Shan; Chen, Yun-Dai

    2013-01-01

    Objective Coronary artery ectasia (CAE) refers to abnormal dilation of coronary artery segments to 1.5 times of adjacent normal ones. Epicardial fat is associated with cardiovascular risk factors. The relationship between CAE and epicardial fat has not yet been investigated. This study aimed to assess the relationship between CAE and epicardial fat volume (EFV) in older people by dual-source computed tomography coronary angiography (CTCA). Methods We prospectively enrolled 1400 older adults who were scheduled for dual-source CTCA. Under reconstruction protocols, patients with abnormal segments 1.5 times larger than the adjacent segments were accepted as CAE. EFV was measured by semi-automated software. Traditional risk factors in CAE patients, as well as the extent of EFV, were analyzed and compared to non-CAE group. Results A total of 885 male and 515 female older patients were enrolled. CAE was identified by univariable analysis in 131 patients and significantly correlated to hypertension, smoking, hyperlipidemia, prior percutaneous coronary intervention and ascending aorta aneurysm. EFV was shown to be significantly higher in CAE patients than patients without ectasia. In multivariable analyses, EFV (P = 0.018), hypertension (P < 0.001) and hyperlipidemia (P < 0.001) were significantly correlated to CAE. There was a significant negative correlation between EFV and Markis classification. Conclusions CAE can be reliably recognized by dual-source CTCA. Epicardial fat might play a role in etiopathogenesis and progression of CAE, providing a new target for treating ectasia. PMID:23610568

  19. Improvement in the quality of the cardiac vein images by optimizing the scan protocol of multidetector-row computed tomography.

    PubMed

    Hara, Tetsuya; Yamashiro, Kohei; Okajima, Katsunori; Hayashi, Takatoshi; Kajiya, Teishi

    2009-11-01

    The present study aimed at optimizing the scan protocol for multidetector-row computed tomography (MDCT) to adequately visualize coronary veins. Circulation time (Cir.T) was defined as the time period from the injection of contrast media into the coronary artery to the pervasion of the contrast media into the coronary sinus as observed by coronary angiography. We investigated the relation between the Cir.T and echocardiographic parameters in 64 patients. The left ventricular end-diastolic diameter (LVDd) and left ventricular end-systolic diameter (LVDs) were correlated with the Cir.T (r = 0.58, P < 0.0001, and r = 0.60, P < 0.0001 respectively). In addition, the left ventricular ejection fraction (LVEF) was negatively correlated with the Cir.T (r = 0.48, P < 0.0001). The average Cir. T was longer in patients with LVEF < 35% (8.0 s vs 6.7 s; P < 0.05) or LVDd > 55 mm (7.9 s vs 6.2 s; P < 0.05) than in the other patients. The quality of the MDCT images of the coronary veins obtained at different scan timings (coronary artery phase and 10 s or 15 s after the coronary artery phase) were graded and classified into four categories (0 = worst, 3 = best) in 25 patients with LVEF < 35%. The delays of 10 and 15 s after the coronary artery phase significantly improved the mean image quality (P < 0.05). The Cir.T was prolonged in patients with low LVEF and LV dilation. An appropriate delay improved the quality of the MDCT images of the coronary veins in patients with LV dysfunction.

  20. Stress Computed Tomography Myocardial Perfusion Imaging: A New Topic in Cardiology.

    PubMed

    Seitun, Sara; Castiglione Morelli, Margherita; Budaj, Irilda; Boccalini, Sara; Galletto Pregliasco, Athena; Valbusa, Alberto; Cademartiri, Filippo; Ferro, Carlo

    2016-02-01

    Since its introduction about 15 years ago, coronary computed tomography angiography has become today the most accurate clinical instrument for noninvasive assessment of coronary atherosclerosis. Important technical developments have led to a continuous stream of new clinical applications together with a significant reduction in radiation dose exposure. Latest generation computed tomography scanners (≥ 64 slices) allow the possibility of performing static or dynamic perfusion imaging during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson), combining both functional and anatomical information in the same examination. In this article, the emerging role and state-of-the-art of myocardial computed tomography perfusion imaging are reviewed and are illustrated by clinical cases from our experience with a second-generation dual-source 128-slice scanner (Somatom Definition Flash, Siemens; Erlangen, Germany). Technical aspects, data analysis, diagnostic accuracy, radiation dose and future prospects are reviewed.

  1. Roles of nuclear cardiology, cardiac computed tomography, and cardiac magnetic resonance: Noninvasive risk stratification and a conceptual framework for the selection of noninvasive imaging tests in patients with known or suspected coronary artery disease.

    PubMed

    Berman, Daniel S; Hachamovitch, Rory; Shaw, Leslee J; Friedman, John D; Hayes, Sean W; Thomson, Louise E J; Fieno, David S; Germano, Guido; Wong, Nathan D; Kang, Xingping; Rozanski, Alan

    2006-07-01

    This review deals with noninvasive imaging for risk stratification and with a conceptual approach to the selection of noninvasive tests in patients with suspected or known chronic coronary artery disease (CAD). Already widely acknowledged with SPECT, there is an increasing body of literature data demonstrating that CT coronary calcium assessment is also of prognostic value. The amount of coronary atherosclerosis, as can be extrapolated from CT coronary calcium score, has been shown to be highly predictive of cardiac events. The principal difference between myocardial perfusion SPECT (MPS) and CT coronary calcium for prognostic application appears to be that the former is an excellent tool for assessing short-term risk, thus effectively guiding decisions regarding revascularization. In contrast, the atherosclerosis imaging methods are likely to provide greater long-term risk assessment and, thus, are more useful in determination of the need for aggressive medical prevention measures. Although the more recent development of CT coronary angiography is promising for diagnosis, there has been no information to date regarding the prognostic value of the CT angiographic data. Similarly, cardiac MRI has not yet been adequately studied for its prognostic content. The selection of the most appropriate test for a given patient depends on the specific question being asked. In patients with a very low likelihood of CAD, no imaging test may be required. In screening the remaining asymptomatic patients, atherosclerosis imaging may be beneficial. In symptomatic patients, MPS, CT coronary angiography, and cardiac MRI play important roles. We consider it likely that, with an increased emphasis on prevention and a concomitant aging of the population, many forms of noninvasive cardiac imaging will continue to grow, with nuclear cardiology continuing to grow.

  2. Cardiac Rehabilitation

    MedlinePlus

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  3. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Inverse computation for cardiac sources using single current dipole and current multipole models

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Ma, Ping; Lu, Hong; Tang, Xue-Zheng; Hua, Ning; Tang, Fa-Kuan

    2009-12-01

    Two cardiac functional models are constructed in this paper. One is a single current model and the other is a current multipole model. Parameters denoting the properties of these two models are calculated by a least-square fit to the measurements using a simulated annealing algorithm. The measured signals are detected at 36 observation nodes by a superconducting quantum interference device (SQUID). By studying the trends of position, orientation and magnitude of the single current dipole model and the current multipole model in the QRS complex during one time span and comparing the reconstructed magnetocardiography (MCG) of these two cardiac models, we find that the current multipole model is a more appropriate model to represent cardiac electrophysiological activity.

  4. Cardiac dosimetric evaluation of deep inspiration breath-hold level variances using computed tomography scans generated from deformable image registration displacement vectors

    SciTech Connect

    Harry, Taylor; Rahn, Doug; Semenov, Denis; Gu, Xuejun; Yashar, Catheryn; Einck, John; Jiang, Steve; Cerviño, Laura

    2016-04-01

    There is a reduction in cardiac dose for left-sided breast radiotherapy during treatment with deep inspiration breath-hold (DIBH) when compared with treatment with free breathing (FB). Various levels of DIBH may occur for different treatment fractions. Dosimetric effects due to this and other motions are a major component of uncertainty in radiotherapy in this setting. Recent developments in deformable registration techniques allow displacement vectors between various temporal and spatial patient representations to be digitally quantified. We propose a method to evaluate the dosimetric effect to the heart from variable reproducibility of DIBH by using deformable registration to create new anatomical computed tomography (CT) scans. From deformable registration, 3-dimensional deformation vectors are generated with FB and DIBH. The obtained deformation vectors are scaled to 75%, 90%, and 110% and are applied to the reference image to create new CT scans at these inspirational levels. The scans are then imported into the treatment planning system and dose calculations are performed. The average mean dose to the heart was 2.5 Gy (0.7 to 9.6 Gy) at FB, 1.2 Gy (0.6 to 3.8 Gy, p < 0.001) at 75% inspiration, 1.1 Gy (0.6 to 3.1 Gy, p = 0.004) at 90% inspiration, 1.0 Gy (0.6 to 3.0 Gy) at 100% inspiration or DIBH, and 1.0 Gy (0.6 to 2.8 Gy, p = 0.019) at 110% inspiration. The average mean dose to the left anterior descending artery (LAD) was 19.9 Gy (2.4 to 46.4 Gy), 8.6 Gy (2.0 to 43.8 Gy, p < 0.001), 7.2 Gy (1.9 to 40.1 Gy, p = 0.035), 6.5 Gy (1.8 to 34.7 Gy), and 5.3 Gy (1.5 to 31.5 Gy, p < 0.001), correspondingly. This novel method enables numerous anatomical situations to be mimicked and quantifies the dosimetric effect they have on a treatment plan.

  5. The repeatability and reproducibility of fetal cardiac ventricular volume calculations utilizing Spatio-Temporal Image Correlation (STIC) and Virtual Organ Computed-aided AnaLysis (VOCAL™)

    PubMed Central

    Hamill, Neil; Romero, Roberto; Hassan, Sonia S; Lee, Wesley; Myers, Stephen A; Mittal, Pooja; Kusanovic, Juan Pedro; Chaiworapongsa, Tinnakorn; Vaisbuch, Edi; Espinoza, Jimmy; Gotsch, Francesca; Carletti, Angela; Goncalves, Luis F.; Yeo, Lami

    2010-01-01

    Objective To quantify the repeatability and reproducibility of fetal cardiac ventricular volumes obtained utilizing STIC and VOCAL™. Methods A technique was developed to compute ventricular volumes using the sub-feature: Contour Finder: Trace. Twenty-five normal pregnancies were evaluated for the following: (1) to compare the coefficient of variation (CV) in ventricular volumes between 15° and 30° rotation; (2) to compare the CV between three methods of quantifying ventricular volumes: (a) Manual Trace (b) Inversion Mode and (c) Contour Finder: Trace; and (3) to determine repeatability by calculating agreement and reliability of ventricular volumes when each STIC was measured twice by 3 observers. Reproducibility was assessed by obtaining two STICs from each of 44 normal pregnancies. For each STIC, 2 ventricular volume calculations were performed, and agreement and reliability were evaluated. Additionally, measurement error was examined. Results (1) Agreement was better with 15° rotation than 30° (15°: 3.6%, 95% CI: 3.0 – 4.2 versus 30°: 7.1%, 95% CI: 5.8 – 8.6; p<0.001); (2) ventricular volumes obtained with Contour Finder: Trace had better agreement than those obtained using either Inversion Mode (Contour Finder: Trace: 3.6%, 95% CI 3.0 – 4.2 versus Inversion Mode: 6.0%, 95% CI 4.9 – 7.2; p < 0.001) or Manual Trace (10.5%, 95% CI 8.7 – 12.5; p < 0.001); (3) ventricular volumes were repeatable with good agreement and excellent reliability for both intra-observer and inter-observer measurements; and 4) ventricular volumes were reproducible with negligible difference in agreement and good reliability. In addition, bias between STIC acquisitions was minimal (<1%; mean percent difference −0.4%, 95% limits of agreement: −5.4 – 5.9). Conclusions Fetal echocardiography utilizing STIC and VOCAL allows repeatable and reproducible calculation of ventricular volumes with the sub-feature Contour Finder: Trace. PMID:19778875

  6. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert . E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  7. Cardiac autonomic nerve distribution and arrhythmia☆

    PubMed Central

    Liu, Quan; Chen, Dongmei; Wang, Yonggang; Zhao, Xin; Zheng, Yang

    2012-01-01

    OBJECTIVE: To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia. DATA RETRIEVAL: A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation as the key words. SELECTION CRITERIA: A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included. MAIN OUTCOME MEASURES: The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase (main markers of cardiac autonomic nerve distribution). In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated. RESULTS: Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system. CONCLUSION: The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in

  8. Cardiac optogenetics

    PubMed Central

    2013-01-01

    Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart. PMID:23457014

  9. Cardiac Surgery

    PubMed Central

    Weisse, Allen B.

    2011-01-01

    Well into the first decades of the 20th century, medical opinion held that any surgical attempts to treat heart disease were not only misguided, but unethical. Despite such reservations, innovative surgeons showed that heart wounds could be successfully repaired. Then, extracardiac procedures were performed to correct patent ductus arteriosus, coarctation of the aorta, and tetralogy of Fallot. Direct surgery on the heart was accomplished with closed commissurotomy for mitral stenosis. The introduction of the heart-lung machine and cardiopulmonary bypass enabled the surgical treatment of other congenital and acquired heart diseases. Advances in aortic surgery paralleled these successes. The development of coronary artery bypass grafting greatly aided the treatment of coronary heart disease. Cardiac transplantation, attempts to use the total artificial heart, and the application of ventricular assist devices have brought us to the present day. Although progress in the field of cardiovascular surgery appears to have slowed when compared with the halcyon times of the past, substantial challenges still face cardiac surgeons. It can only be hoped that sufficient resources and incentive can carry the triumphs of the 20th century into the 21st. This review covers past developments and future opportunities in cardiac surgery. PMID:22163121

  10. Multimodality imaging for resuscitated sudden cardiac death.

    PubMed

    Chen, Yingming Amy; Deva, Djeven; Kirpalani, Anish; Prabhudesai, Vikram; Marcuzzi, Danny W; Graham, John J; Verma, Subodh; Jimenez-Juan, Laura; Yan, Andrew T

    2015-01-01

    We present a case that elegantly illustrates the utility of two novel noninvasive imaging techniques, computed tomography (CT) coronary angiography and cardiac MRI, in the diagnosis and management of a 27-year-old man with exertion-induced cardiac arrest caused by an anomalous right coronary artery. CT coronary angiography with 3D reformatting delineated the interarterial course of an anomalous right coronary artery compressed between the aorta and pulmonary artery, whereas cardiac MRI showed a small myocardial infarction in the right coronary artery territory not detected on echocardiography. This case highlights the value of novel multimodality imaging techniques in the risk stratification and management of patients with resuscitated cardiac arrest.

  11. RELATION OF LEFT VENTRICULAR MASS AND CONCENTRIC REMODELING TO EXTENT OF CORONARY ARTERY DISEASE BY COMPUTED TOMOGRAPHY IN PATIENTS WITHOUT LEFT VENTRICULAR HYPERTROPHY: ROMICAT STUDY

    PubMed Central

    Truong, Quynh A.; Toepker, Michael; Mahabadi, Amir A.; Bamberg, Fabian; Rogers, Ian S.; Blankstein, Ron; Brady, Thomas J.; Nagurney, John T.; Hoffmann, Udo

    2010-01-01

    Objective Cardiac computed tomography (CT) allows for simultaneous assessment of left ventricular mass (LVM) and coronary artery disease (CAD). We aimed to determine whether LVM, LVM index (LVMi), and the left ventricular (LV) geometric pattern of concentric remodeling are associated with the extent of CAD in patients without left ventricular hypertrophy (LVH). Methods In 348 patients from the ROMICAT trial, 64-slice CT was performed and LVM measured at end-diastole. We used 3 LVM indexation criteria to obtain 3 cohorts: LVM indexed to body surface area by echocardiography (n=337) and CT criteria (n=325), and by height2.7 (n=326). The cohorts were subdivided into concentric remodeling and normal geometry. Extent of coronary plaque was classified based on a 17-segment model, treated as a continuous variable, and stratified into 3 groups: 0 segments, 1–4 segments, >4 segments. Results Patients with >4 segments of coronary plaque had higher LVM (Δ12.8–15.1g) and LVMi (Δ4.0–5.5g/m2 and Δ2.2g/m2.7) than those without CAD (all p≤0.03). After multivariable adjustment, LVM and LVMi remained independent predictors of extent of coronary plaque, with 0.27–0.29 segments more plaque per 20 g increase of LVM (all p=0.02), 0.32–0.34 segments more plaque per 10 g/m2 increase of LVMi (both p=0.02), and 0.80 segments more plaque per 10 g/m2.7 increase of LVMi (p=0.008). Concentric remodeling patients had 1.1–1.3 segments more plaque than those with normal geometry (all p≤0.05). Patients with >4 segments of plaque had 2-fold increase odds (all p≤0.05) of having concentric remodeling as compared to those without CAD. Conclusion Increased LVM, LVMi, and concentric remodeling are associated with a greater degree of coronary plaque burden in patients without LVH. These findings could provide an indication to intensify medical therapy in patients with subclinical CAD and hypertension. PMID:19696685

  12. Ultrasound in cardiac trauma.

    PubMed

    Saranteas, Theodosios; Mavrogenis, Andreas F; Mandila, Christina; Poularas, John; Panou, Fotios

    2017-04-01

    In the perioperative period, the emergency department or the intensive care unit accurate assessment of variable chest pain requires meticulous knowledge, diagnostic skills, and suitable usage of various diagnostic modalities. In addition, in polytrauma patients, cardiac injury including aortic dissection, pulmonary embolism, acute myocardial infarction, and pericardial effusion should be immediately revealed and treated. In these patients, arrhythmias, mainly tachycardia, cardiac murmurs, or hypotension must alert physicians to suspect cardiovascular trauma, which would potentially be life threatening. Ultrasound of the heart using transthoracic and transesophageal echocardiography are valuable diagnostic tools that can be used interchangeably in conjunction with other modalities such as the electrocardiogram and computed tomography for the diagnosis of cardiovascular abnormalities in trauma patients. Although ultrasound of the heart is often underused in the setting of trauma, it does have the advantages of being easily accessible, noninvasive, and rapid bedside assessment tool. This review article aims to analyze the potential cardiac injuries in trauma patients, and to provide an elaborate description of the role of echocardiography for their accurate diagnosis.

  13. About Cardiac Arrest

    MedlinePlus

    ... Thromboembolism Aortic Aneurysm More About Cardiac Arrest Updated:Mar 10,2017 What is cardiac arrest? Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart ...

  14. Clinical utility of (18)F-FDG positron emission tomography/computed tomography scan vs. (99m)Tc-HMPAO white blood cell single-photon emission computed tomography in extra-cardiac work-up of infective endocarditis.

    PubMed

    Lauridsen, Trine K; Iversen, Kasper K; Ihlemann, Nikolaj; Hasbak, Philip; Loft, Annika; Berthelsen, Anne K; Dahl, Anders; Dejanovic, Danijela; Albrecht-Beste, Elisabeth; Mortensen, Jann; Kjær, Andreas; Bundgaard, Henning; Bruun, Niels Eske

    2017-01-03

    The extra-cardiac work-up in infective endocarditis (IE) comprises a search for primary and secondary infective foci. Whether (18)FDG-PET/CT or WBC-SPECT/CT is superior in detection of clinically relevant extra-cardiac manifestations in IE is unexplored. The objectives of this study were to identify the numbers of positive findings detected by each imaging modality, to evaluate the clinical relevance of these findings and to define the reproducibility for extra-cardiac foci in patients with definite IE. Each modality was evaluated for numbers and location of positive extra-cardiac foci in patients with definite IE. A team of 2 × 2 cardiologists evaluated each finding to determine clinical relevance. Clinical utility was determined by 4 criteria converted into an ordinal scale. Using the manifestation with highest clinical utility rating in each patient, the clinical impact of the two imaging modalities was expressed in a clinical utility score. To evaluate reproducibility for each modality, an imaging core laboratory reviewed all findings. In 55 IE patients, 91 pathological foci were found by FDG-PET/CT and 37 foci were identified by WBC-SPECT/CT (p < 0.001). The clinical utility of FDG-PET/CT was significantly higher than that of WBC-SPECT/CT when comparing clinical utility score (2.06 vs. 1.17; p = 0.01). In assessment of extra-cardiac diagnostics in IE, inter-observer reproducibility was substantial for WBC-SPECT/CT (k 0.69, 95% CI 0.49-0.89) and substantial to excellent for FDG-PET/CT (k 0.79, 95% CI 0.61-0.98). FDG-PET/CT has a significantly higher clinical utility score than WBC SPECT/CT and is potentially superior to WBC-SPECT/CT in detection of extra-cardiac pathology in patients with IE.

  15. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography: comparison with cine magnetic resonance imaging.

    PubMed

    Belge, Bénédicte; Coche, Emmanuel; Pasquet, Agnès; Vanoverschelde, Jean-Louis J; Gerber, Bernhard L

    2006-07-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134+/-51 and 67+/-56 ml) were similar to those by MR (137+/-57 and 70+/-60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55+/-21 vs. 56+/-21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3+/-1.8 vs. 8.8+/-1.9 mm and 12.7+/-3.4 vs. 13.3+/-3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54+/-30 vs. 51+/-31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR.

  16. Integrative modeling of the cardiac ventricular myocyte

    PubMed Central

    Winslow, Raimond L.; Cortassa, Sonia; O'Rourke, Brian; Hashambhoy, Yasmin L.; Rice, John Jeremy; Greenstein, Joseph L.

    2011-01-01

    Cardiac electrophysiology is a discipline with a rich 50-year history of experimental research coupled with integrative modeling which has enabled us to achieve a quantitative understanding of the relationships between molecular function and the integrated behavior of the cardiac myocyte in health and disease. In this paper, we review the development of integrative computational models of the cardiac myocyte. We begin with a historical overview of key cardiac cell models that helped shape the field. We then narrow our focus to models of the cardiac ventricular myocyte and describe these models in the context of their subcellular functional systems including dynamic models of voltage-gated ion channels, mitochondrial energy production, ATP-dependent and electrogenic membrane transporters, intracellular Ca dynamics, mechanical contraction, and regulatory signal transduction pathways. We describe key advances and limitations of the models as well as point to new directions for future modeling research. PMID:20865780

  17. Cardiac xenotransplantation.

    PubMed

    DiSesa, V J

    1997-12-01

    Heart failure is an important medical and public health problem. Although medical therapy is effective for many people, the only definitive therapy is heart transplantation, which is limited severely by the number of donors. Mechanical devices presently are used as "bridges" to transplantation. Their widespread use may solve the donor shortage problem, but at present, mechanical devices are limited by problems related to blood clotting, power supply, and foreign body infection. Cardiac xenotransplantation using animal donors is a potential biologic solution to the donor organ shortage. The immune response, consisting of hyperacute rejection, acute vascular rejection, and cellular rejection, currently prevents clinical xenotransplantation. Advances in the solution of these problems have been made using conventional immunosuppressive drugs and newer agents whose use is based on an understanding of important steps in xenoimmunity. The most exciting approaches use tools of molecular biology to create genetically engineered donors and to induce states of donor and recipient bone marrow chimerism and tolerance in xenogeneic organ recipients. The successful future strategy may use a combination of a genetically engineered donor and a chimeric recipient with or without nonspecific immunosuppressive drugs.

  18. Parametric modelling of cardiac system multiple measurement signals: an open-source computer framework for performance evaluation of ECG, PCG and ABP event detectors.

    PubMed

    Homaeinezhad, M R; Sabetian, P; Feizollahi, A; Ghaffari, A; Rahmani, R

    2012-02-01

    The major focus of this study is to present a performance accuracy assessment framework based on mathematical modelling of cardiac system multiple measurement signals. Three mathematical algebraic subroutines with simple structural functions for synthetic generation of the synchronously triggered electrocardiogram (ECG), phonocardiogram (PCG) and arterial blood pressure (ABP) signals are described. In the case of ECG signals, normal and abnormal PQRST cycles in complicated conditions such as fascicular ventricular tachycardia, rate dependent conduction block and acute Q-wave infarctions of inferior and anterolateral walls can be simulated. Also, continuous ABP waveform with corresponding individual events such as systolic, diastolic and dicrotic pressures with normal or abnormal morphologies can be generated by another part of the model. In addition, the mathematical synthetic PCG framework is able to generate the S4-S1-S2-S3 cycles in normal and in cardiac disorder conditions such as stenosis, insufficiency, regurgitation and gallop. In the PCG model, the amplitude and frequency content (5-700 Hz) of each sound and variation patterns can be specified. The three proposed models were implemented to generate artificial signals with varies abnormality types and signal-to-noise ratios (SNR), for quantitative detection-delineation performance assessment of several ECG, PCG and ABP individual event detectors designed based on the Hilbert transform, discrete wavelet transform, geometric features such as area curve length (ACLM), the multiple higher order moments (MHOM) metric, and the principal components analysed geometric index (PCAGI). For each method the detection-delineation operating characteristics were obtained automatically in terms of sensitivity, positive predictivity and delineation (segmentation) error rms and checked by the cardiologist. The Matlab m-file script of the synthetic ECG, ABP and PCG signal generators are available in the Appendix.

  19. Subperiosteal Orbital Hemorrhage Complicating Cardiac Surgery

    SciTech Connect

    Peden, Marc C.; Bhatti, M. Tariq

    2004-09-15

    Subperiosteal orbital hemorrhage (SPOH) following cardiac surgery has not been previously reported. We present a patient who developed diplopia and right eye proptosis immediately after cardiac surgery for a mitral valve repair and coronary artery bypass graft. A computed tomography (CT) study demonstrated a right superior SPOH. The diplopia and proptosis resolved spontaneously within 4 weeks. Follow-up CT showed complete resolution of the SPOH.

  20. Physics of Cardiac Arrhythmogenesis

    NASA Astrophysics Data System (ADS)

    Karma, Alain

    2013-04-01

    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  1. Cardiac tamponade (image)

    MedlinePlus

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  2. Cardiac conduction system

    MedlinePlus Videos and Cool Tools

    ... cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components ... the cardiac conduction system's electrical activity in the heart.

  3. Sudden Cardiac Arrest

    MedlinePlus

    ... from American Heart Association Aneurysms and Dissections Angina Arrhythmia Bundle Branch Block Cardiomyopathy Carotid Artery Disease Chronic ... terms: SCA, sudden cardiac death (SCD), sudden death, arrhythmias, ... ventricular fibrillation, defibrillator, automatic cardiac defibrillator ( ...

  4. What Is Cardiac Rehabilitation?

    MedlinePlus

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  5. Behcet Disease Presenting With Cardiac and Pulmonary Masses.

    PubMed

    Ng, Ming-Yen; Boutet, Alexandre; Carette, Simon; de Perrot, Marc; Cusimano, Robert James; Nguyen, Elsie Thao

    2015-09-01

    Computed tomography and magnetic resonance imaging features of inflammatory intracardiac and pulmonary masses secondary to Behcet disease have not been well described in the literature. We present a case of Behcet disease, presenting with enhancing cardiac and pulmonary inflammatory masses that mimicked the imaging appearance of metastatic cardiac angiosarcoma. Subsequent magnetic resonance imaging examination showed the mass reduced in size with immunosuppressive therapy. This case highlights the importance of considering Behcet disease in the differential diagnosis for an enhancing cardiac mass.

  6. Cardiac ion channels

    PubMed Central

    Priest, Birgit T; McDermott, Jeff S

    2015-01-01

    Ion channels are critical for all aspects of cardiac function, including rhythmicity and contractility. Consequently, ion channels are key targets for therapeutics aimed at cardiac pathophysiologies such as atrial fibrillation or angina. At the same time, off-target interactions of drugs with cardiac ion channels can be the cause of unwanted side effects. This manuscript aims to review the physiology and pharmacology of key cardiac ion channels. The intent is to highlight recent developments for therapeutic development, as well as elucidate potential mechanisms for drug-induced cardiac side effects, rather than present an in-depth review of each channel subtype. PMID:26556552

  7. Mathematical Models of Cardiac Pacemaking Function

    NASA Astrophysics Data System (ADS)

    Li, Pan; Lines, Glenn T.; Maleckar, Mary M.; Tveito, Aslak

    2013-10-01

    Over the past half century, there has been intense and fruitful interaction between experimental and computational investigations of cardiac function. This interaction has, for example, led to deep understanding of cardiac excitation-contraction coupling; how it works, as well as how it fails. However, many lines of inquiry remain unresolved, among them the initiation of each heartbeat. The sinoatrial node, a cluster of specialized pacemaking cells in the right atrium of the heart, spontaneously generates an electro-chemical wave that spreads through the atria and through the cardiac conduction system to the ventricles, initiating the contraction of cardiac muscle essential for pumping blood to the body. Despite the fundamental importance of this primary pacemaker, this process is still not fully understood, and ionic mechanisms underlying cardiac pacemaking function are currently under heated debate. Several mathematical models of sinoatrial node cell membrane electrophysiology have been constructed as based on different experimental data sets and hypotheses. As could be expected, these differing models offer diverse predictions about cardiac pacemaking activities. This paper aims to present the current state of debate over the origins of the pacemaking function of the sinoatrial node. Here, we will specifically review the state-of-the-art of cardiac pacemaker modeling, with a special emphasis on current discrepancies, limitations, and future challenges.

  8. Impact on Image Quality and Radiation Dose of Third-Generation Dual-Source Computed Tomography of the Coronary Arteries.

    PubMed

    Apfaltrer, Georg; Szolar, Dieter H; Wurzinger, Eric; Takx, Richard A P; Nance, John W; Dutschke, Anja; Tschauner, Sebastian; Loewe, Christian; Ringl, Helmut; Sorantin, Erich; Apfaltrer, Paul

    2017-04-15

    The aim of this study was to assess the image quality (IQ) and radiation dose of third-generation dual-source computed tomography (CT) coronary angiography (cCTA) in comparison with 64-slice single-source CT. This retrospective study included 140 patients (73 men, mean age 62 ± 11 years) with low-to-intermediate probability of coronary artery disease who underwent either third-generation dual-source cCTA using prospectively electrocardiography-triggered high-pitch spiral acquisition (n = 70) (group 1) or retrospective electrocardiography-gated cCTA on a 64-slice CT system (n = 70) (group 2). Contrast-to-noise and signal-to-noise ratios were measured within the aorta and coronary arteries. Subjective IQ was assessed using a 5-point Likert scale. Effective dose was estimated using specific conversion factors. The contrast-to-noise ratio of group 1 was significantly higher than group 2 at all levels (all p <0.001). Signal-to-noise ratio of group 1 was also significantly higher than group 2 (p <0.05), except for the distal left circumflex artery. Subjective IQ for group 1 was rated significantly better than for group 2 (median score [25th to 75th percentile]: 1 [1 to 2] vs 2 [2 to 3]; p <0.001). The median effective dose was 1.55 mSv (1.09 to 1.88) in group 1 versus 12.29 mSv (11.63 to 14.36) in group 2 (p <0.001) which corresponds to a mean radiation dose reduction of 87.4%. In conclusion, implementation of third-generation dual-source CT system for cCTA leads to improved IQ with significant radiation dose savings.

  9. A new cardiac auscultation simulator.

    PubMed

    Takashina, T; Masuzawa, T; Fukui, Y

    1990-12-01

    We have successfully developed a new cardiac auscultation simulator by applying recently developed digital and computer technology, which digitally records, stores, modifies, and plays back heart sounds and murmurs characteristic of various heart diseases. The simulator is capable of playing back different heart sounds or murmurs at each auscultatory site (aortic, pulmonic, tricuspid, and mitral) of a human chest-sized mannequin (made of urethane foam), through four built-in speakers. We were able to listen to accurate reproductions of heart sounds and murmurs at the same timing as in real patients by any type of stethoscope used in routine medical practice. This compact and portable educational apparatus, which simulates realistic auscultatory sounds, will impact greatly on the medical training of cardiac auscultation for physicians, medical students, nurses, and paramedicals.

  10. High-performance computing and networking as tools for accurate emission computed tomography reconstruction.

    PubMed

    Passeri, A; Formiconi, A R; De Cristofaro, M T; Pupi, A; Meldolesi, U

    1997-04-01

    It is well known that the quantitative potential of emission computed tomography (ECT) relies on the ability to compensate for resolution, attenuation and scatter effects. Reconstruction algorithms which are able to take these effects into account are highly demanding in terms of computing resources. The reported work aimed to investigate the use of a parallel high-performance computing platform for ECT reconstruction taking into account an accurate model of the acquisition of single-photon emission tomographic (SPET) data. An iterative algorithm with an accurate model of the variable system response was ported on the MIMD (Multiple Instruction Multiple Data) parallel architecture of a 64-node Cray T3D massively parallel computer. The system was organized to make it easily accessible even from low-cost PC-based workstations through standard TCP/IP networking. A complete brain study of 30 (64x64) slices could be reconstructed from a set of 90 (64x64) projections with ten iterations of the conjugate gradients algorithm in 9 s, corresponding to an actual speed-up factor of 135. This work demonstrated the possibility of exploiting remote high-performance computing and networking resources from hospital sites by means of low-cost workstations using standard communication protocols without particular problems for routine use. The achievable speed-up factors allow the assessment of the clinical benefit of advanced reconstruction techniques which require a heavy computational burden for the compensation effects such as variable spatial resolution, scatter and attenuation. The possibility of using the same software on the same hardware platform with data acquired in different laboratories with various kinds of SPET instrumentation is appealing for software quality control and for the evaluation of the clinical impact of the reconstruction methods.

  11. Digital retrospective motion-mode display and processing of electron beam cine-computed tomography and other cross-sectional cardiac imaging techniques

    NASA Astrophysics Data System (ADS)

    Reed, Judd E.; Rumberger, John A.; Buithieu, Jean; Behrenbeck, Thomas; Breen, Jerome F.; Sheedy, Patrick F., II

    1995-05-01

    Electron beam computed tomography is unparalleled in its ability to consistently produce high quality dynamic images of the human heart. Its use in quantification of left ventricular dynamics is well established in both clinical and research applications. However, the image analysis tools supplied with the scanners offer a limited number of analysis options. They are based on embedded computer systems which have not been significantly upgraded since the scanner was introduced over a decade ago in spite of the explosive improvements in available computer power which have occured during this period. To address these shortcomings, a workstation-based ventricular analysis system has been developed at our institution. This system, which has been in use for over five years, is based on current workstation technology and therefore has benefited from the periodic upgrades in processor performance available to these systems. The dynamic image segmentation component of this system is an interactively supervised, semi-automatic surface identification and tracking system. It characterizes the endocardial and epicardial surfaces of the left ventricle as two concentric 4D hyper-space polyhedrons. Each of these polyhedrons have nearly ten thousand vertices which are deposited into a relational database. The right ventricle is also processed in a similar manner. This database is queried by other custom components which extract ventricular function parameters such as regional ejection fraction and wall stress. The interactive tool which supervises dynamic image segmentation has been enhanced with a temporal domain display. The operator interactively chooses the spatial location of the endpoints of a line segment while the corresponding space/time image is displayed. These images, with content resembling M-Mode echocardiography, benefit form electron beam computed tomography's high spatial and contrast resolution. The segmented surfaces are displayed along with the imagery. These

  12. Cardiac thrombi mistaken for metastasis in recurrent melanoma.

    PubMed

    Galiuto, Leonarda; Locorotondo, Gabriella; Fedele, Elisa; Danza, Maria L; De Vito, Elena; Masi, Ambra; Favoccia, Carla; Rebuzzi, Antonio G; Crea, Filippo

    2015-01-01

    Intra-cardiac thrombi can be incidentally found in recurrent melanoma and need careful assessment. An 81-year-old woman, with a history of malignant nasopharyngeal melanoma, was evaluated by echocardiography and cardiac magnetic resonance due to the detection of undefined masses localized both in right atrium and ventricle during contrast-enhanced thoraco-abdominal computed tomography.

  13. Comprehensive cardiac assessment with multislice computed tomography: evaluation of left ventricular function and perfusion in addition to coronary anatomy in patients with previous myocardial infarction

    PubMed Central

    Henneman, M M; Schuijf, J D; Jukema, J W; Lamb, H J; de Roos, A; Dibbets, P; Stokkel, M P; van der Wall, E E; Bax, J J

    2006-01-01

    Objective To evaluate a comprehensive multislice computed tomography (MSCT) protocol in patients with previous infarction, including assessment of coronary artery stenoses, left ventricular (LV) function and perfusion. Patients and methods 16‐slice MSCT was performed in 21 patients with previous infarction; from the MSCT data, coronary artery stenoses, (regional and global) LV function and perfusion were assessed. Invasive coronary angiography and gated single‐photon emission computed tomography (SPECT) served as the reference standards for coronary artery stenoses and LV function/perfusion, respectively. Results 236 of 241 (98%) coronary artery segments were interpretable on MSCT. The sensitivity and specificity for detection of stenoses were 91% and 97%. Pearson's correlation showed excellent agreement for assessment of LV ejection fraction between MSCT and SPECT (49 (13)% v 53 (12)%, respectively, r  =  0.85). Agreement for assessment of regional wall motion was excellent (92%, κ  =  0.77). In 68 of 73 (93%) segments, MSCT correctly identified a perfusion defect as compared with SPECT, whereas the absence of perfusion defects was correctly detected in 277 of 284 (98%) segments. Conclusions MSCT permits accurate, non‐invasive assessment of coronary artery stenoses, LV function and perfusion in patients with previous infarction. All parameters can be assessed from a single dataset. PMID:16740917

  14. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  15. ESTIMATION OF CARDIAC CT ANGIOGRAPHY RADIATION DOSE TOWARD THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVEL FOR CCTA IN IRAN.

    PubMed

    Hosseini Nasab, Seyed Mohammad Bagher; Shabestani-Monfared, Ali; Deevband, Mohammad Reza; Paydar, Reza; Nabahati, Mehrdad

    2016-08-29

    In recent years, with the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography (CCTA) has emerged as a useful diagnostic imaging modality as a non-invasive assessment of coronary heart disease. CT produces a larger radiation dose than other imaging tests and cardiac CT involves higher radiation dose with the advances in the spatial and temporal resolution. The aims of this study are patient dose assessment and establishment of national diagnostic reference level for CCTA in Iran. A questionnaire was sent to CCTA centers. Data for patient and CT protocols were obtained. The volumetric CT dose index (CTDIvol), dose length product (DLP) and total DLP were considered in the 32 cm standard body phantom. Calculation of estimated effective dose (ED) was obtained by multiplying the DLP by a conversion factor [k = 0.014 mSv (mGy·cm)(-1)]. Mean value of CTDIvol and DLP for CCTA was 50 mGy and 825 mGy·cm. The third quartile (75th) of the distribution of mean CTDIvol (66.54 mGy) and DLP (1073 mGy·cm) values was expressed as the diagnostic reference level (DRL) for CCTA in Iran. The median of ED was 10.26 mSv and interquartile range of ED was 7.08-15.03 mSv. A large variety in CTDIvol and DLP among CT scanner and different sites due to variability in CT parameter is noted. It seems that training could help to reduce patient's dose.

  16. Return of Viable Cardiac Function After Sonographic Cardiac Standstill in Pediatric Cardiac Arrest.

    PubMed

    Steffen, Katherine; Thompson, W Reid; Pustavoitau, Aliaksei; Su, Erik

    2017-01-01

    Sonographic cardiac standstill during adult cardiac arrest is associated with failure to get return to spontaneous circulation. This report documents 3 children whose cardiac function returned after standstill with extracorporeal membranous oxygenation. Sonographic cardiac standstill may not predict cardiac death in children.

  17. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    SciTech Connect

    Wetzel, D.; Wetzel, L; Wetzel, M; Lodder, R

    2009-01-01

    still the first line of defense. However, with the fidelity of 64-slice CT imaging, this technique has recently become an option when the patient presents with symptoms of reduced arterial flow. Single photon emission computerized tomography (SPECT) treadmill exercise testing is a standard non-invasive test for decreased perfusion of heart muscle, but is time consuming and not suited for emergent evaluation. Once the invasive clinical option of catherization is chosen, this provides the opportunity for intravascular ultrasound (IVUS) imaging. As the probe is pulled through the artery, the diameter at different parts is measurable, and monochrome contrast in the constricted area reveals the presence of tissue with a different ultrasonic response. Also, via an optical catheter with a fiber-optic conductor, the possibly of spectroscopic analysis of arterial walls is now a reality. In this case, the optical transducer is coupled to a near-infrared spectrometer. Revealing the arterial chemical health means that plaque vulnerability and imminent risk could be assessed by the physician. The classical emergency use of catherization involves a contrast agent and dynamic X-ray imaging to locate the constriction, determine its severity, and possibly perform angioplasty, and stent placement.

  18. Clinical and economic consequences of non-cardiac incidental findings detected on cardiovascular computed tomography performed prior to transcatheter aortic valve implantation (TAVI).

    PubMed

    Lindsay, Alistair C; Sriharan, Mona; Lazoura, Olga; Sau, Arunashis; Roughton, Michael; Jabbour, Richard J; Di Mario, Carlo; Davies, Simon W; Moat, Neil E; Padley, Simon P G; Rubens, Michael B; Nicol, Edward D

    2015-10-01

    Transcatheter aortic valve implantation (TAVI) is an effective treatment option for patients with severe degenerative aortic valve stenosis who are high risk for conventional surgery. Computed tomography (CT) performed prior to TAVI can detect pathologies that could influence outcomes following the procedure, however the incidence, cost, and clinical impact of incidental findings has not previously been investigated. 279 patients underwent CT; 188 subsequently had TAVI and 91 were declined. Incidental findings were classified as clinically significant (requiring treatment), indeterminate (requiring further assessment), or clinically insignificant. The primary outcome measure was all-cause mortality up to 3 years. Costs incurred by additional investigations resultant to incidental findings were estimated using the UK Department of Health Payment Tariff. Incidental findings were common in both the TAVI and medical therapy cohorts (54.8 vs. 70.3%; P = 0.014). Subsequently, 45 extra investigations were recommended for the TAVI cohort, at an overall average cost of £32.69 per TAVI patient. In a univariate model, survival was significantly associated with the presence of a clinically significant or indeterminate finding (HR 1.61; P = 0.021). However, on multivariate analysis outcomes after TAVI were not influenced by any category of incidental finding. Incidental findings are common on CT scans performed prior to TAVI. However, the total cost involved in investigating these findings is low, and incidental findings do not independently identify patients with poorer outcomes after TAVI. The discovery of an incidental finding on CT should not necessarily influence or delay the decision to perform TAVI.

  19. Automated cardiac sarcomere analysis from second harmonic generation images

    NASA Astrophysics Data System (ADS)

    Garcia-Canadilla, Patricia; Gonzalez-Tendero, Anna; Iruretagoyena, Igor; Crispi, Fatima; Torre, Iratxe; Amat-Roldan, Ivan; Bijnens, Bart H.; Gratacos, Eduard

    2014-05-01

    Automatic quantification of cardiac muscle properties in tissue sections might provide important information related to different types of diseases. Second harmonic generation (SHG) imaging provides a stain-free microscopy approach to image cardiac fibers that, combined with our methodology of the automated measurement of the ultrastructure of muscle fibers, computes a reliable set of quantitative image features (sarcomere length, A-band length, thick-thin interaction length, and fiber orientation). We evaluated the performance of our methodology in computer-generated muscle fibers modeling some artifacts that are present during the image acquisition. Then, we also evaluated it by comparing it to manual measurements in SHG images from cardiac tissue of fetal and adult rabbits. The results showed a good performance of our methodology at high signal-to-noise ratio of 20 dB. We conclude that our automated measurements enable reliable characterization of cardiac fiber tissues to systematically study cardiac tissue in a wide range of conditions.

  20. Getting better together? Opportunities and limitations for technology-facilitated social support in cardiac rehabilitation.

    PubMed

    Maitland, Julie

    2011-01-01

    Social support has long been positively correlated with cardiac outcomes. However, sources of tension surrounding peer-involvement in the period following acute cardiac events are well documented. Informed by a previous study of patient perspectives of peer-involvement in cardiac rehabilitation, this paper draws from the cardiac and computing literature to provide actionable insights into how technology could be designed to promote appropriate peer-involvement and the challenges that may be faced when designing technologies to support the unsupported.

  1. Incremental prognostic value of coronary computed tomographic angiography over coronary artery calcium score for risk prediction of major adverse cardiac events in asymptomatic diabetic individuals

    PubMed Central

    Min, James K.; Labounty, Troy M.; Gomez, Millie J.; Achenbach, Stephan; Al-Mallah, Mouaz; Budoff, Matthew J.; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Cheng, Victor; Chinnaiyan, Kavitha M.; Chow, Benjamin; Cury, Ricardo; Delago, Augustin; Dunning, Allison; Feuchtner, Gudrun; Hadamitzky, Martin; Hausleiter, Jorg; Kaufmann, Philipp; Kim, Yong-Jin; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Berman, Daniel S.

    2015-01-01

    Background Coronary artery disease (CAD) diagnosis by coronary computed tomographic angiography (CCTA) is useful for identification of symptomatic diabetic individuals at heightened risk for death. Whether CCTA-detected CAD enables improved risk assessment of asymptomatic diabetic individuals beyond clinical risk factors and coronary artery calcium scoring (CACS) remains unexplored. Methods From a prospective 12-center international registry of 27,125 individuals undergoing CCTA, we identified 400 asymptomatic diabetic individuals without known CAD. Coronary stenosis by CCTA was graded as 0%, 1–49%, 50–69%, and ≥70%. CAD was judged on a per-patient, per-vessel and per-segment basis as maximal stenosis severity, number of vessels with ≥50% stenosis, and coronary segments weighted for stenosis severity (segment stenosis score), respectively. We assessed major adverse cardiovascular events (MACE) – inclusive of mortality, nonfatal myocardial infarction (MI), and late target vessel revascularization ≥90 days (REV) – and evaluated the incremental utility of CCTA for risk prediction, discrimination and reclassification. Results Mean age was 60.4 ± 9.9 years; 65.0% were male. At a mean follow-up 2.4 ± 1.1 years, 33 MACE occurred (13 deaths, 8 MI, 12 REV) [8.25%; annualized rate 3.4%]. By univariate analysis, per-patient maximal stenosis [hazards ratio (HR) 2.24 per stenosis grade, 95% confidence interval (CI) 1.61–3.10, p < 0.001], increasing numbers of obstructive vessels (HR 2.30 per vessel, 95% CI 1.75–3.03, p < 0.001) and segment stenosis score (HR 1.14 per segment, 95% CI 1.09–1.19, p < 0.001) were associated with increased MACE. After adjustment for CAD risk factors and CACS, maximal stenosis (HR 1.80 per grade, 95% CI 1.18–2.75, p = 0.006), number of obstructive vessels (HR 1.85 per vessel, 95% CI 1.29–2.65, p < 0.001) and segment stenosis score (HR 1.11 per segment, 95% CI 1.05–1.18, p < 0.001) were associated with increased risk of

  2. Cardiac Hegemony of Senescence

    PubMed Central

    Siddiqi, Sailay; Sussman, Mark A.

    2013-01-01

    Cardiac senescence and age-related disease development have gained general attention and recognition in the past decades due to increased accessibility and quality of health care. The advancement in global civilization is complementary to concerns regarding population aging and development of chronic degenerative diseases. Cardiac degeneration has been rigorously studied. The molecular mechanisms of cardiac senescence are on multiple cellular levels and hold a multilayer complexity level, thereby hampering development of unambiguous treatment protocols. In particular, the synergistic exchange of the senescence phenotype through a senescence secretome between myocytes and stem cells appears complicated and is of great future therapeutic value. The current review article will highlight hallmarks of senescence, cardiac myocyte and stem cell senescence, and the mutual exchange of senescent secretome. Future cardiac cell therapy approaches require a comprehensive understanding of myocardial senescence to improve therapeutic efficiency as well as efficacy. PMID:24349878

  3. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 appropriate use criteria for cardiac computed tomography. A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance.

    PubMed

    Taylor, Allen J; Cerqueira, Manuel; Hodgson, John McB; Mark, Daniel; Min, James; O'Gara, Patrick; Rubin, Geoffrey D; Kramer, Christopher M; Berman, Daniel; Brown, Alan; Chaudhry, Farooq A; Cury, Ricardo C; Desai, Milind Y; Einstein, Andrew J; Gomes, Antoinette S; Harrington, Robert; Hoffmann, Udo; Khare, Rahul; Lesser, John; McGann, Christopher; Rosenberg, Alan; Schwartz, Robert; Shelton, Marc; Smetana, Gerald W; Smith, Sidney C

    2010-11-23

    The American College of Cardiology Foundation (ACCF), along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical scenarios where cardiac computed tomography (CCT) is frequently considered. The present document is an update to the original CCT/cardiac magnetic resonance (CMR) appropriateness criteria published in 2006, written to reflect changes in test utilization, to incorporate new clinical data, and to clarify CCT use where omissions or lack of clarity existed in the original criteria (1). The indications for this review were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Ninety-three clinical scenarios were developed by a writing group and scored by a separate technical panel on a scale of 1 to 9 to designate appropriate use, inappropriate use, or uncertain use. In general, use of CCT angiography for diagnosis and risk assessment in patients with low or intermediate risk or pretest probability for coronary artery disease (CAD) was viewed favorably, whereas testing in high-risk patients, routine repeat testing, and general screening in certain clinical scenarios were viewed less favorably. Use of noncontrast computed tomography (CT) for calcium scoring was rated as appropriate within intermediate- and selected low-risk patients. Appropriate applications of CCT are also within the category of cardiac structural and functional evaluation. It is anticipated that these results will have an impact on physician decision making, performance, and reimbursement policy, and that they will help guide future research.

  4. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 Appropriate Use Criteria for Cardiac Computed Tomography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance.

    PubMed

    Taylor, Allen J; Cerqueira, Manuel; Hodgson, John McB; Mark, Daniel; Min, James; O'Gara, Patrick; Rubin, Geoffrey D

    2010-01-01

    The American College of Cardiology Foundation (ACCF), along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical scenarios where cardiac computed tomography (CCT) is frequently considered. The present document is an update to the original CCT/cardiac magnetic resonance (CMR) appropriateness criteria published in 2006, written to reflect changes in test utilization, to incorporate new clinical data, and to clarify CCT use where omissions or lack of clarity existed in the original criteria (1). The indications for this review were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Ninety-three clinical scenarios were developed by a writing group and scored by a separate technical panel on a scale of 1 to 9 to designate appropriate use, inappropriate use, or uncertain use. In general, use of CCT angiography for diagnosis and risk assessment in patients with low or intermediate risk or pretest probability for coronary artery disease (CAD) was viewed favorably, whereas testing in high-risk patients, routine repeat testing, and general screening in certain clinical scenarios were viewed less favorably. Use of noncontrast computed tomography (CT) for calcium scoring was rated as appropriate within intermediate- and selected low-risk patients. Appropriate applications of CCT are also within the category of cardiac structural and functional evaluation. It is anticipated that these results will have an impact on physician decision making, performance, and reimbursement policy, and that they will help guide future research.

  5. ACCF/SCCT/ACR/AHA/ASE/ASNC/NASCI/SCAI/SCMR 2010 Appropriate Use Criteria for Cardiac Computed Tomography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance.

    PubMed

    Taylor, Allen J; Cerqueira, Manuel; Hodgson, John McB; Mark, Daniel; Min, James; O'Gara, Patrick; Rubin, Geoffrey D

    2010-11-23

    The American College of Cardiology Foundation, along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical scenarios where cardiac computed tomography (CCT) is frequently considered. The present document is an update to the original CCT/cardiac magnetic resonance appropriateness criteria published in 2006, written to reflect changes in test utilization, to incorporate new clinical data, and to clarify CCT use where omissions or lack of clarity existed in the original criteria. The indications for this review were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Ninety-three clinical scenarios were developed by a writing group and scored by a separate technical panel on a scale of 1 to 9 to designate appropriate use, inappropriate use, or uncertain use. In general, use of CCT angiography for diagnosis and risk assessment in patients with low or intermediate risk or pretest probability for coronary artery disease was viewed favorably, whereas testing in high-risk patients, routine repeat testing, and general screening in certain clinical scenarios were viewed less favorably. Use of noncontrast computed tomography for calcium scoring was rated as appropriate within intermediate- and selected low-risk patients. Appropriate applications of CCT are also within the category of cardiac structural and functional evaluation. It is anticipated that these results will have an impact on physician decision making, performance, and reimbursement policy, and that they will help guide future research.

  6. Considerations on an automatic computed tomography tube current modulation system.

    PubMed

    Moro, Luca; Panizza, Denis; D'Ambrosio, Daniela; Carne, Irene

    2013-10-01

    The scope of this study was to evaluate the effects on radiation output and image noise varying the acquisition parameters with an automatic tube current modulation (ATCM) system in computed tomography (CT). Chest CT examinations of an anthropomorphic phantom were acquired using a GE LightSpeed VCT 64-slice tomograph. Acquisitions were performed using different pitch, slice thickness and noise index (NI) values and varying the orientation of the scanned projection radiograph (SPR). The radiation output was determined by the CT dose index (CTDIvol). Image noise was evaluated measuring the standard deviation of CT numbers in several regions of interest. The radiation output was lower if the SPR was acquired in the anterior-posterior projection. The radiation dose with the posterior-anterior SPR was higher, because the divergence of the X-ray beam magnifies the anatomical structures closest to the tube, especially the spinal column, and this leads the ATCM system to estimate higher patient attenuation values and, therefore, to select higher tube current values. The NI was inversely proportional to the square root of the CTDIvol and, with fixed NI, the CTDIvol increased as the slice thickness decreased. This study suggests some important issues to use the GE ATCM system efficiently.

  7. Diagnosis of traumatic cardiac contusion

    SciTech Connect

    Waxman, K.; Soliman, M.H.; Braunstein, P.; Formosa, P.; Cohen, A.J.; Matsuura, P.; Mason, G.R.

    1986-06-01

    Cardiac contusion following blunt chest trauma remains a diagnostic problem because of a lack of sensitive diagnostic tests. This study evaluated thallous chloride Tl 201 single-photon-emission computed tomography in a series of 48 patients following blunt chest trauma. Of the 48 patients, 23 had normal scans. None of these patients proved to have serious arrhythmias during three days of continuous monitoring. Of 25 patients with abnormal or ambiguous studies, five (20%) developed serious arrhythmias requiring therapy. Single-photon-emission computed tomography scanning thus was sensitive in indicating that group of patients at risk of serious arrhythmias, and may therefore prove to be a useful screening test to determine the need for hospitalization and arrhythmia monitoring following blunt chest trauma.

  8. Cardiac tumors: echo assessment.

    PubMed

    Mankad, Rekha; Herrmann, Joerg

    2016-12-01

    Cardiac tumors are exceedingly rare (0.001-0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  9. Cardiac tumors: echo assessment

    PubMed Central

    Mankad, Rekha

    2016-01-01

    Cardiac tumors are exceedingly rare (0.001–0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses. PMID:27600455

  10. Update on cardiac imaging techniques 2014.

    PubMed

    Mahía-Casado, Patricia; García-Orta, Rocío; Gómez de Diego, José J; Barba-Cosials, Joaquín; Rodríguez-Palomares, José F; Aguadé-Bruix, Santiago

    2015-02-01

    In this article, we review the contributions of the most important imaging techniques used in cardiology, reported in 2014. Echocardiography remains the cornerstone for diagnosing and monitoring valvular heart disease, and there has been a continuing effort to improve quantification of this condition and obtain prognostic parameters for follow-up. The study of regional myocardial function is anchored in the diagnosis of subclinical ventricular dysfunction, and 3-dimensional transesophageal echocardiography has become the perfect ally in interventional procedures for structural heart disease. Cardiac magnetic resonance imaging and cardiac computed tomography are the focus of most publications on cardiac imaging in ischemic heart disease, reflecting their consolidated use in clinical practice. Nuclear medicine excels in the study of myocardial viability after interventional treatment of acute coronary syndromes and its performance is validated in the diagnosis of ischemic heart disease.

  11. The benefits of the Atlas of Human Cardiac Anatomy website for the design of cardiac devices.

    PubMed

    Spencer, Julianne H; Quill, Jason L; Bateman, Michael G; Eggen, Michael D; Howard, Stephen A; Goff, Ryan P; Howard, Brian T; Quallich, Stephen G; Iaizzo, Paul A

    2013-11-01

    This paper describes how the Atlas of Human Cardiac Anatomy website can be used to improve cardiac device design throughout the process of development. The Atlas is a free-access website featuring novel images of both functional and fixed human cardiac anatomy from over 250 human heart specimens. This website provides numerous educational tutorials on anatomy, physiology and various imaging modalities. For instance, the 'device tutorial' provides examples of devices that were either present at the time of in vitro reanimation or were subsequently delivered, including leads, catheters, valves, annuloplasty rings and stents. Another section of the website displays 3D models of the vasculature, blood volumes and/or tissue volumes reconstructed from computed tomography and magnetic resonance images of various heart specimens. The website shares library images, video clips and computed tomography and MRI DICOM files in honor of the generous gifts received from donors and their families.

  12. [Cardiac manifestations of mitochondrial diseases].

    PubMed

    Ritzenthaler, Thomas; Luis, David; Hullin, Thomas; Fayssoil, Abdallah

    2015-05-01

    Mitochondrial diseases are multi-system disorders in relation with mitochondrial DNA and/or nuclear DNA abnormalities. Clinical pictures are heterogeneous, involving endocrine, cardiac, neurologic or sensory systems. Cardiac involvements are morphological and electrical disturbances. Prognosis is worsened in case of cardiac impairment. Treatments are related to the type of cardiac dysfunction including medication or pacemaker implantation.

  13. Robust temporal alignment of multimodal cardiac sequences

    NASA Astrophysics Data System (ADS)

    Perissinotto, Andrea; Queirós, Sandro; Morais, Pedro; Baptista, Maria J.; Monaghan, Mark; Rodrigues, Nuno F.; D'hooge, Jan; Vilaça, João. L.; Barbosa, Daniel

    2015-03-01

    Given the dynamic nature of cardiac function, correct temporal alignment of pre-operative models and intraoperative images is crucial for augmented reality in cardiac image-guided interventions. As such, the current study focuses on the development of an image-based strategy for temporal alignment of multimodal cardiac imaging sequences, such as cine Magnetic Resonance Imaging (MRI) or 3D Ultrasound (US). First, we derive a robust, modality-independent signal from the image sequences, estimated by computing the normalized cross-correlation between each frame in the temporal sequence and the end-diastolic frame. This signal is a resembler for the left-ventricle (LV) volume curve over time, whose variation indicates different temporal landmarks of the cardiac cycle. We then perform the temporal alignment of these surrogate signals derived from MRI and US sequences of the same patient through Dynamic Time Warping (DTW), allowing to synchronize both sequences. The proposed framework was evaluated in 98 patients, which have undergone both 3D+t MRI and US scans. The end-systolic frame could be accurately estimated as the minimum of the image-derived surrogate signal, presenting a relative error of 1.6 +/- 1.9% and 4.0 +/- 4.2% for the MRI and US sequences, respectively, thus supporting its association with key temporal instants of the cardiac cycle. The use of DTW reduces the desynchronization of the cardiac events in MRI and US sequences, allowing to temporally align multimodal cardiac imaging sequences. Overall, a generic, fast and accurate method for temporal synchronization of MRI and US sequences of the same patient was introduced. This approach could be straightforwardly used for the correct temporal alignment of pre-operative MRI information and intra-operative US images.

  14. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    MedlinePlus

    ... Graft (CABG) Surgery Atherosclerosis Coronary Artery Disease (CAD) Heart Attack • Home • About Heart Attacks • Warning Signs of a ... Heart Attack • Heart Attack Tools & Resources • Support Network Heart Attack Tools & Resources What Is a Heart Attack? How ...

  15. Cardiac Catheterization (For Kids)

    MedlinePlus

    ... done during a cardiac catheterization include: closing small holes inside the heart repairing leaky or narrow heart ... bandage. It's normal for the site to be black and blue, red, or slightly swollen for a ...

  16. Cardiac Catheterization (For Teens)

    MedlinePlus

    ... a person will have only a small puncture hole where the catheter was put in. Doctors usually ... done using a cardiac catheterization, including: closing small holes inside the heart repairing leaky or narrow heart ...

  17. Cardiac glycoside overdose

    MedlinePlus

    ... found in the leaves of the digitalis (foxglove) plant. This plant is the original source of this medicine. People ... Digitoxin (Crystodigin) Digoxin (Lanoxicaps, Lanoxin) Besides the foxglove plant, cardiac glycosides also occur naturally in plants such ...

  18. Cardiac imaging in adults

    SciTech Connect

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  19. [Intrinsic cardiac ganglia].

    PubMed

    Birand, Ahmet

    2008-12-01

    Heart has been considered as the source and the seat of emotions, passion and love. But from the dawn of XIXth century, scientists have emphasized that the heart, though life depends on its ceaseless activity, is merely a electromechanical pump, pumping oxygenated blood. Nowadays, we all know that heart pumps blood commensurate with the needs of the body and this unending toil, and its regulation depends on the intrinsic properties of the myocardium, Frank-Starling Law and neurohumoral contribution. It has been understood, though not clearly enough, that these time-tensions may cause structural or functional cardiac impairments and arrhythmias are related to the autonomic nervous system. Less well known and less taken in account in daily cardiology practice is the fact that heart has an intrinsic cardiac nervous system, or "heart brain" consisting of complex ganglia, intrinsic cardiac ganglia containing afferent (receiving), local circuit (interneurons) and efferent (transmitting) sympathetic and parasympathetic neurons. This review enlightens structural and functional aspects of intrinsic cardiac ganglia as the very first step in the regulation of cardiac function. This issue is important for targets of pharmacological treatment and techniques of cardiac surgery interventions as repair of septal defects, valvular interventions and congenital corrections.

  20. Computational cardiology: how computer simulations could be used to develop new therapies and advance existing ones

    PubMed Central

    Trayanova, Natalia A.; O'Hara, Thomas; Bayer, Jason D.; Boyle, Patrick M.; McDowell, Kathleen S.; Constantino, Jason; Arevalo, Hermenegild J.; Hu, Yuxuan; Vadakkumpadan, Fijoy

    2012-01-01

    This article reviews the latest developments in computational cardiology. It focuses on the contribution of cardiac modelling to the development of new therapies as well as the advancement of existing ones for cardiac arrhythmias and pump dysfunction. Reviewed are cardiac modelling efforts aimed at advancing and optimizing existent therapies for cardiac disease (defibrillation, ablation of ventricular tachycardia, and cardiac resynchronization therapy) and at suggesting novel treatments, including novel molecular targets, as well as efforts to use cardiac models in stratification of patients likely to benefit from a given therapy, and the use of models in diagnostic procedures. PMID:23104919

  1. Patient-specific models of cardiac biomechanics

    NASA Astrophysics Data System (ADS)

    Krishnamurthy, Adarsh; Villongco, Christopher T.; Chuang, Joyce; Frank, Lawrence R.; Nigam, Vishal; Belezzuoli, Ernest; Stark, Paul; Krummen, David E.; Narayan, Sanjiv; Omens, Jeffrey H.; McCulloch, Andrew D.; Kerckhoffs, Roy C. P.

    2013-07-01

    Patient-specific models of cardiac function have the potential to improve diagnosis and management of heart disease by integrating medical images with heterogeneous clinical measurements subject to constraints imposed by physical first principles and prior experimental knowledge. We describe new methods for creating three-dimensional patient-specific models of ventricular biomechanics in the failing heart. Three-dimensional bi-ventricular geometry is segmented from cardiac CT images at end-diastole from patients with heart failure. Human myofiber and sheet architecture is modeled using eigenvectors computed from diffusion tensor MR images from an isolated, fixed human organ-donor heart and transformed to the patient-specific geometric model using large deformation diffeomorphic mapping. Semi-automated methods were developed for optimizing the passive material properties while simultaneously computing the unloaded reference geometry of the ventricles for stress analysis. Material properties of active cardiac muscle contraction were optimized to match ventricular pressures measured by cardiac catheterization, and parameters of a lumped-parameter closed-loop model of the circulation were estimated with a circulatory adaptation algorithm making use of information derived from echocardiography. These components were then integrated to create a multi-scale model of the patient-specific heart. These methods were tested in five heart failure patients from the San Diego Veteran's Affairs Medical Center who gave informed consent. The simulation results showed good agreement with measured echocardiographic and global functional parameters such as ejection fraction and peak cavity pressures.

  2. Computed tomography quality indexes: evaluation experience

    NASA Astrophysics Data System (ADS)

    Strocchi, Sabina; Vite, Cristina; Novario, Raffaele; Cacciatori, Marco; Frigerio, Giovanna; Conte, Leopoldo

    2009-02-01

    Aim of this work was to identify proper figures of merit (FoM's) to quantitatively and objectively assess the whole acquisition process of a CT image and to evaluate which are more significant. Catphan® phantom images where acquired with a 64 slices computed tomography system, with head and abdomen protocols. Automatic exposure modulation system was on, with different settings. We defined three FoM's (Q, Q1 and Q2) including image quality parameters and acquisition modalities; two of them (Q and Q1) include also a radiation dose quantity, the third (Q2) does not. Then we drew from these the comparable FoM's (CNR, Q1 *, Q2), that do not have dose in their definitions, in order to investigate how they depend on perceived image quality. The FoM's were evaluated for each series. At the same time, expert observers evaluated the number of low contrast inserts seen in the phantom' images. The considered CNR, Q1*, Q2 FoM's are linearly related to the perceived image quality for both the acquisition protocols (head: r2=0.91;0.94;0.91; abdomen: r2=0.93;0.93;0.85). Q and Q1 values analysis shows that these FoM's can distinguish between different acquisition modalities (head or abdomen) with statistically significant difference (p<0.05). The studied FoM's can be usefully used to quantitatively and objectively assess the whole CT image acquisition process. Those FoM's including also radiation dose (Q, Q1) can be used to objectively quantify the equilibrium between image quality and radiation dose for a certain acquisition modality.

  3. Intra-procedural imaging of the left atrium and pulmonary veins with rotational angiography: a comparison of anatomy obtained by pre-procedural cardiac computed tomography and trans-thoracic echocardiography.

    PubMed

    Park, Yae Min; Kim, Mi Na; Choi, Jong-Il; Lim, Hong Euy; Park, Seong-Mi; Park, Sang Weon; Shim, Wan Joo; Kim, Young-Hoon

    2013-10-01

    This study evaluated the feasibility and accuracy of three-dimensional rotational angiography (3DRA) to determine the anatomy of the left atrium (LA) and pulmonary veins (PVs) compared with cardiac computed tomography (CCT) and trans-thoracic echocardiography (TTE). One hundred two patients (56.1 ± 9.9 years, 86 males) with an indication for atrial fibrillation ablation were prospectively enrolled. Intra-procedural 3DRA was performed with power injected contrast medium (20 cc/s for 4 s, 240°) in the LA. 3DRA images of the LA and PVs were assessed qualitatively and then compared quantitatively. LA volume measured by 3DRA, CCT and TTE were compared. The majority of 3DRA acquisitions were optimal in delineating the right-side LA-PV (95 % for right superior PV and 96 % for right inferior PV) and left inferior PV anatomy (91 %), whereas it was optimal in only 63 % of left superior PV and 73 % of the LA appendage. The circumferences of PV ostia identified by 3DRA and CCT were correlated in four PVs (r = 0.57 for right superior PV, r = 0.67 for right inferior PV, r = 0.60 for left superior PV, and r = 0.52 for left inferior PV, p < 0.001). The mean LA volume measured by 3DRA (120 ± 32 mL) was greater than that found by CCT (109 ± 35 mL) or TTE (64 ± 23 mL), but the 3DRA LA volume measurements correlated well with those of CCT (r = 0.83, p < 0.001) and TTE (r = 0.69, p < 0.001). Intra-procedural 3DRA provided anatomical accuracy of LA and PVs comparable to those of CCT. However, optimal delineation of the left superior PV and LA appendage was limited. The LA volume determined by 3DRA was well correlated with those of CCT and TTE, despite different absolute values of each.

  4. [Psychosomatic aspects of cardiac arrhythmias].

    PubMed

    Siepmann, Martin; Kirch, Wilhelm

    2010-07-01

    Emotional stress facilitates the occurrence of cardiac arrhythmias including sudden cardiac death. The prevalence of anxiety and depression is increased in cardiac patients as compared to the normal population. The risk of cardiovascular mortality is enhanced in patients suffering from depression. Comorbid anxiety disorders worsen the course of cardiac arrhythmias. Disturbance of neurocardiac regulation with predominance of the sympathetic tone is hypothesized to be causative for this. The emotional reaction to cardiac arrhythmias is differing to a large extent between individuals. Emotional stress may result from coping with treatment of cardiac arrhythmias. Emotional stress and cardiac arrhythmias may influence each other in the sense of a vicious circle. Somatoform cardiac arrhythmias are predominantly of psychogenic origin. Instrumental measures and frequent contacts between physicians and patients may facilitate disease chronification. The present review is dealing with the multifaceted relationships between cardiac arrhythmias and emotional stress. The underlying mechanisms and corresponding treatment modalities are discussed.

  5. Cardiac cavernous hemangioma and multiple pulmonary cavernous hemangiomas.

    PubMed

    Yang, Lili; Dai, Jun; Xiao, Ying; Cheng, Henghui; Ruan, Qiurong

    2014-02-01

    We describe for the first time a rare coexistence of a cardiac cavernous hemangioma with multiple pulmonary cavernous hemangiomas. Computed tomography revealed bilateral pulmonary nodules, left pleural effusion, and pericardial effusion. Positron emission tomography showed a pericardial neoplasm. Pathologically, multiple large dilated vascular spaces, lined by a single layer of endothelial cells and filled with blood, were revealed in both the cardiac tumor and the pulmonary nodules. Immunohistochemical examination of the lining cells showed positivity for CD31, FLI1, FVIII, and CD34. Taken together, these findings led to the diagnosis of cardiac cavernous hemangioma and multiple pulmonary cavernous hemangiomas.

  6. Iatrogenic Claudication from a Vascular Closure Device after Cardiac Catheterization

    PubMed Central

    Hermann, Luke; Chow, Evelyn; Duvall, W. Lane

    2010-01-01

    We report a case of iatrogenic claudication as a result of a misplaced percutaneous arterial closure device (PACD) used to obtain hemostasis after cardiac catheterization. The patient presented one week after his procedure with complaints suggestive of right lower extremity claudication. Computed tomographic angiography demonstrated a near total occlusion of the right common femoral artery from a PACD implemented during the cardiac catheterization. The use of PACD’s to obtain rapid hemostasis is estimated to occur in half of all cardiac catheterizations. Ischemic complications as a result of these devices must be considered when evaluating post procedural patients with extremity complaints. PMID:21293776

  7. Cardiac output determinations with ear piece densitometry.

    PubMed

    Hedenstierna, G; Schildt, B

    1975-01-01

    The results of cardiac output determinations by a dye dilution technique were compared using (a) a dichromatic earpiece which was calibrated as a flow-through cuvette, but also permitted automatic computing by virtue of a pressure capsule, and (b) an ordinary flow-through densitometer. Eleven subjects, some with cardio-pulmonary disease, were investigated. Cardiac outputs were systematically overestimated when automatically computed. The results obtained by manual calculation with the ear-piece corresponded more nearly with those derived from the flow-through cuvette, but still with a deviation from the identity line and with a residual standard deviation of 0.8 l/min. Double determinations had a residual standard deviation of 0.7 l/min. Despite its ease of handling, an earpiece densitometer seems to be too unreliable to be suitable for routine use.

  8. Stroke of a cardiac myxoma origin

    PubMed Central

    Yuan, Shi-Min; Humuruola, Gulimila

    2015-01-01

    Objective The clinical features of cardiac myxoma stroke have not been sufficiently described. Debates remain concerning the options and timing of treatment and the clinical outcomes are unknown. This article aims to highlight the pertinent aspects of this rare condition. Methods Data source of the present study came from a comprehensive literature collection of cardiac myxoma stroke in PubMed, Google search engine and Highwire Press for the year range 2000-2014. Results Young adults, female predominance, single cerebral vessel (mostly the middle cerebral artery), multiple territory involvements and solitary left atrial myxoma constituted the outstanding characteristics of this patient setting. The most common affected cerebral vessel (the middle cerebral artery) and areas (the basal ganglion, cerebellum and parietal and temporal regions) corresponded well to the common manifestations of this patient setting, such as conscious alteration, ataxia, hemiparesis and hemiplegia, aphasia and dysarthria. Initial computed tomography scan carried a higher false negative rate for the diagnosis of cerebral infarction than magnetic resonance imaging did. A delayed surgical resection of cardiac myxoma was associated with an increased risk of potential consequences in particular otherwise arterial embolism. The mortality rate of this patient population was 15.3%. Conclusion Cardiac myxoma stroke is rare. Often does it affect young females. For an improved diagnostic accuracy, magnetic resonance imaging of the brain and echocardiography are imperative for young stroke patients in identifying the cerebral infarct and determining the stroke of a cardiac origin. Immediate thrombolytic therapy may completely resolve the cerebral stroke and improve the neurologic function of the patients. An early surgical resection of cardiac myxoma is recommended in patients with not large territory cerebral infarct. PMID:26107455

  9. [A monitor of the biomechanical cardiac activity].

    PubMed

    Masloboev, Iu P; Okhritskiĭ, A A; Prilutskiĭ, D A; Selishchev, S V

    2004-01-01

    A monitor of the biomechanical cardiac activity is described, which was elaborated on the basis of the accelerometer sensor and sigma-delta ADC for the purpose of registering the ballistocardiograms and seismocardiograms. The device ensures a non-stop signal recording for as long as 8 hours with the data being preserved in an inbuilt memory. Data are fed to the computer through the USB port. An algorithm is suggested for recordings processing by using the neuron-net technologies.

  10. Cardiac echinococcosis--a rare echocardiographic diagnosis.

    PubMed Central

    Siwach, S. B.; Katyal, V. K.; Jagdish

    1997-01-01

    A 30 year old female admitted for evaluation of left chest pain was suspected to have multiple cardiac hydatid cysts. The diagnosis was established by cross sectional echocardiography and computed tomography, supported by enzyme linked immunosorbent assay (ELISA) for echinococcosis. Medical therapy altered the echopattern of the cysts but failed to reduce cystic masses. Surgery was advocated but refused by the patient. Images PMID:9155623

  11. Inter-individual variance and cardiac cycle dependency of aortic root dimensions and shape as assessed by ECG-gated multi-slice computed tomography in patients with severe aortic stenosis prior to transcatheter aortic valve implantation: is it crucial for correct sizing?

    PubMed

    Lehmkuhl, Lukas; Foldyna, Borek; Von Aspern, Konstantin; Lücke, Christian; Grothoff, Matthias; Nitzsche, Stefan; Kempfert, Jörg; Haensig, Martin; Rastan, Ardawan; Walther, Thomas; Mohr, Friedrich-Wilhelm; Gutberlet, Matthias

    2013-03-01

    To evaluate the inter-individual variance and the variability of the aortic root dimensions during the cardiac cycle by computed tomography (CT) in patients with severe aortic stenosis prior to transcatheter aortic valve implantation (TAVI). Fifty-six patients (m/w = 16/40, 81 ± 6.8 years), scheduled for a transapical aortic valve implantation with available preprocedural ECG-gated CT were retrospectively included. The evaluation included sizing of the aortic annulus and the aortic sinus, measurements of the coronary topography, aortic valve planimetry and scoring of calcification. The new defined aortic annulus sphericity ratio revealed a mostly elliptical shape with increasing diastolic deformation. The calculated effective diameter (ED), determined from the annulus' lumen area, turned out to be the parameter least affected from cardiac cycle changes while systolic and diastolic annulus dimensions and shape (diameter and area) differed significantly (p < 0.001). In about 70 % of the patients with relevant paravalvular leaks the finally implanted prosthesis was too small according to the CT based calculated ED. The ostial height of the coronaries showed a high variability with a critical minimum range <5 mm. The degree of the aortic calcification did not have an influence on the aortic annulus deformation during the cardiac cycle, but on the occurrence of paravalvular leaks. The aortic root anatomy demonstrated a high inter-individual variability and cardiac cycle dependency. These results must be strongly considered during the patient evaluation prior to TAVI to avoid complications. The systolic effective diameter, as measured by ECG-gated CT, represents an appropriate parameter for sizing the aortic annulus.

  12. Fetal cardiac scanning today.

    PubMed

    Allan, Lindsey

    2010-07-01

    The ability to examine the structure of the fetal heart in real-time started over 30 years ago now. The field has seen very great advances since then, both in terms of technical improvements in ultrasound equipment and in dissemination of operator skills. A great deal has been learnt about normal cardiac function in the human fetus throughout gestation and how it is affected by pathologies of pregnancy. There is increasing recognition of abnormal heart structure during routine obstetric scanning, allowing referral for specialist diagnosis and counselling. It is now possible to make accurate diagnosis of cardiac malformations as early as 12 weeks of gestation. Early diagnosis of a major cardiac malformation in the fetus can provide the parents with a comprehensive prognosis, enabling them to make the most informed choice about the management of the pregnancy.

  13. Autoantibodies and Cardiac Arrhythmias

    PubMed Central

    Lee, Hon-Chi; Huang, Kristin T. L.; Wang, Xiao-Li; Shen, Win-Kuang

    2013-01-01

    Autoimmune diseases are associated with significant morbidity and mortality, afflicting about 5% of the population of the United States. They encompass a wide range of disorders that affect all organs of the human body and have a predilection for women. In the past, autoimmune pathogenesis was not thought to be a major mechanism for cardiovascular disorders, and potential relationships remain understudied. However, accumulating evidence suggests that a number of vascular and cardiac conditions are autoimmune-mediated. Recent studies indicate that autoantibodies play an important role in the development of cardiac arrhythmias, including atrial fibrillation, modulation of autonomic influences on heart rate and rhythm, conduction system abnormalities, and ventricular arrhythmias. This manuscript will review the current evidence for the role of autoantibodies in the development of cardiac arrhythmias. PMID:21740882

  14. Toothache of cardiac origin.

    PubMed

    Kreiner, M; Okeson, J P

    1999-01-01

    Pain referred to the orofacial structures can sometimes be a diagnostic challenge for the clinician. In some instances, a patient may complain of tooth pain that is completely unrelated to any dental source. This poses a diagnostic and therapeutic problem for the dentist. Cardiac pain most commonly radiates to the left arm, shoulder, neck, and face. In rare instances, angina pectoris may present as dental pain. When this occurs, an improper diagnosis frequently leads to unnecessary dental treatment or, more significantly, a delay of proper treatment. This delay may result in the patient experiencing an acute myocardial infarction. It is the dentist's responsibility to establish a proper diagnosis so that the treatment will be directed toward the source of pain and not to the site of pain. This article reviews the literature concerning referred pain of cardiac origin and presents a case report of toothache of cardiac origin.

  15. Drug Treatment of Cardiac Failure

    PubMed Central

    Achong, M. R.; Kumana, C. R.

    1982-01-01

    Treatment of cardiac failure should first be aimed at reversing or ameliorating the underlying pathological processes. This review highlights the common problems and pitfalls in the use of digoxin, diuretics and vasodilators in patients with cardiac failure. PMID:21289849

  16. Mechanisms of cardiac arrhythmias

    PubMed Central

    Tse, Gary

    2015-01-01

    Blood circulation is the result of the beating of the heart, which provides the mechanical force to pump oxygenated blood to, and deoxygenated blood away from, the peripheral tissues. This depends critically on the preceding electrical activation. Disruptions in the orderly pattern of this propagating cardiac excitation wave can lead to arrhythmias. Understanding of the mechanisms underlying their generation and maintenance requires knowledge of the ionic contributions to the cardiac action potential, which is discussed in the first part of this review. A brief outline of the different classification systems for arrhythmogenesis is then provided, followed by a detailed discussion for each mechanism in turn, highlighting recent advances in this area. PMID:27092186

  17. Mechanisms of Cardiac Regeneration

    PubMed Central

    Uygur, Aysu; Lee, Richard T.

    2016-01-01

    Adult humans fail to regenerate their hearts following injury, and this failure to regenerate myocardium is a leading cause of heart failure and death worldwide. Although all adult mammals appear to lack significant cardiac regeneration potential, some vertebrates can regenerate myocardium throughout life. In addition, new studies indicate that mammals have cardiac regeneration potential during development and very soon after birth. The mechanisms of heart regeneration among model organisms, including neonatal mice, appear remarkably similar. Orchestrated waves of inflammation, matrix deposition and remodeling, and cardiomyocyte proliferation are commonly seen in heart regeneration models. Understanding why adult mammals develop extensive scarring instead of regeneration is a crucial goal for regenerative biology. PMID:26906733

  18. Emergency Cardiac Care: An Update

    PubMed Central

    Swanson, Richard W.

    1988-01-01

    The authors review the new guidelines for basic life support and advanced cardiac life support and the recommended changes to the standards. The changes recommended for basic life support will simplify the psychomotor skills required. The recommended changes to the guidelines for advanced cardiac life support, which include discontinuing the use of isoproterenol and limiting the use of sodium bicarbonate in cardiac arrest, are likely to improve survival rates. Controversies in the management of cardiac arrest are also discussed. PMID:21253157

  19. A computerised dichromatic earpiece densitometer for the measurement of cardiac output.

    PubMed

    Robinson, P S; Crowther, A; Jenkins, B S; Webb-Peploe, M M; Coltart, D J

    1979-07-01

    This study assesses a precalibrated dichromatic earpiece densitometer and microprocessor for the measurement of cardiac output by indocyanine green dye dilution. The measured cardiac output is compared with values of cardiac output simultaneously determined using a cuvette densitometer. The microprocessor computation of cardiac output agreed very closely with the cardiac output determined by manual calculation from the same dye dilution curves (standard deviation +/- 1.47%). The reproducibility of the earpiece densitometer (standard deviation +/- 5.2%) was virtually identical to that of the cuvette densitometer (+/- 5.3%). In a comparison of earpiece and cuvette densitometers for 60 measurements of cardiac output following pulmonary arterial injection of dye and for 50 measurements following femoral venous injection of dye, correlation coefficients were 0.83 and 0.78 and the standard deviations of the differences of simultaneous measurements were 7.2% and 8.3% respectively. The instrument offers an accurate reproducible and relatively noninvasive technique for measuring cardiac output.

  20. Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study.

    PubMed

    Li, Jian; Zhou, Haiying; Zuo, Decheng; Hou, Kun-Mean; De Vaulx, Christophe

    2014-01-01

    As the symptoms and signs of heart diseases that cause sudden cardiac death, cardiac arrhythmia has attracted great attention. Due to limitations in time and space, traditional approaches to cardiac arrhythmias detection fail to provide a real-time continuous monitoring and testing service applicable in different environmental conditions. Integrated with the latest technologies in ECG (electrocardiograph) analysis and medical care, the pervasive computing technology makes possible the ubiquitous cardiac care services, and thus brings about new technical challenges, especially in the formation of cardiac care architecture and realization of the real-time automatic ECG detection algorithm dedicated to care devices. In this paper, a ubiquitous cardiac care prototype system is presented with its architecture framework well elaborated. This prototype system has been tested and evaluated in all the clinical-/home-/outdoor-care modes with a satisfactory performance in providing real-time continuous cardiac arrhythmias monitoring service unlimitedly adaptable in time and space.

  1. Ultrasound imaging in teaching cardiac physiology.

    PubMed

    Johnson, Christopher D; Montgomery, Laura E A; Quinn, Joe G; Roe, Sean M; Stewart, Michael T; Tansey, Etain A

    2016-09-01

    This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such as stroke volume, ejection fraction, and cardiac output. By repeating the measurements from a subject after a brief exercise period, an increase in stroke volume and ejection fraction are easily demonstrable, potentially with or without an increase in left ventricular end-diastolic volume (which indicates preload). Thus, factors that affect cardiac performance can readily be discussed. This activity may be performed as a practical demonstration and visualized using an overhead projector or networked computers, concentrating on using the ultrasound images to teach basic physiological principles. This has proved to be highly popular with students, who reported a significant improvement in their understanding of Frank-Starling's law of the heart with ultrasound imaging.

  2. Antimyosin imaging in cardiac transplant rejection

    SciTech Connect

    Johnson, L.L.; Cannon, P.J. )

    1991-09-01

    Fab fragments of antibodies specific for cardiac myosin have been labeled with indium-111 and injected intravenously into animals and into patients with heart transplants. The antibodies, developed by Khaw, Haber, and co-workers, localize in cardiac myocytes that have been damaged irreversibly by ischemia, myocarditis, or the rejection process. After clearance of the labeled antibody from the cardiac blood pool, planar imaging or single photon emission computed tomography is performed. Scintigrams reveal the uptake of the labeled antimyosin in areas of myocardium undergoing transplant rejection. In animal studies, the degree of antimyosin uptake appears to correlate significantly with the degree of rejection assessed at necropsy. In patients, the correlation between scans and pathologic findings from endomyocardial biopsy is not as good, possibly because of sampling error in the endomyocardial biopsy technique. The scan results at 1 year correlate with either late complications (positive) or benign course (negative). Current limitations of the method include slow blood clearance, long half-life of indium-111, and hepatic uptake. Overcoming these limitations represents a direction for current research. It is possible that from these efforts a noninvasive approach to the diagnosis and evaluation of cardiac transplantation may evolve that will decrease the number of endomyocardial biopsies required to evaluate rejection. This would be particularly useful in infants and children. 31 references.

  3. Reconstruction of dynamic gated cardiac SPECT

    SciTech Connect

    Jin Mingwu; Yang Yongyi; King, Michael A.

    2006-11-15

    In this paper we propose an image reconstruction procedure which aims to unify gated single photon emission computed tomography (SPECT) and dynamic SPECT into a single method. We divide the cardiac cycle into a number of gate intervals as in gated SPECT, but treat the tracer distribution for each gate as a time-varying signal. By using both dynamic and motion-compensated temporal regularization, our reconstruction procedure will produce an image sequence that shows both cardiac motion and time-varying tracer distribution simultaneously. To demonstrate the proposed reconstruction method, we simulated gated cardiac perfusion imaging using the gated mathematical cardiac-torso (gMCAT) phantom with Tc99m-Teboroxime as the imaging agent. Our results show that the proposed method can produce more accurate reconstruction of gated dynamic images than independent reconstruction of individual gate frames with spatial smoothness alone. In particular, our results show that the former could improve the contrast to noise ratio of a simulated perfusion defect by as much as 100% when compared to the latter.

  4. Cardiac troponins and high-sensitivity cardiac troponin assays.

    PubMed

    Conrad, Michael J; Jarolim, Petr

    2014-03-01

    Measurement of circulating cardiac troponins I and T has become integral to the diagnosis of myocardial infarction. This article discusses the structure and function of the troponin complex and the release of cardiac troponin molecules from the injured cardiomyocyte into the circulation. An overview of current cardiac troponin assays and their classification according to sensitivity is presented. The diagnostic criteria, role, and usefulness of cardiac troponin for myocardial infarction are discussed. In addition, several examples are given of the usefulness of high-sensitivity cardiac troponin assays for short-term and long-term prediction of adverse events.

  5. Cardiac T1 Imaging

    PubMed Central

    Jerosch-Herold, Michael; Kwong, Raymond Y.

    2014-01-01

    T1 mapping of the heart has evolved into a valuable tool to evaluate myocardial tissue properties, with or without contrast injection, including assessment of myocardial edema and free water content, extra-cellular volume (expansion), and most recently cardiomyocyte hypertrophy. The MRI pulse sequence techniques developed for these applications have had to address at least two important considerations for cardiac applications: measure magnetization inversion recoveries during cardiac motion with sufficient temporal resolution for the shortest expected T1 values, and, secondly, obtain these measurements within a time during which a patient can comfortably suspend breathing. So-called Look-Locker techniques, and variants thereof, which all sample multiple points of a magnetization recovery after each magnetization preparation have therefore become a mainstay in this field. The rapid pace of advances and new findings based on cardiac T1 mapping for assessment of diffuse fibrosis, or myocardial edema show that these techniques enrich the capabilities of MRI for myocardial tissue profiling, which is arguably unmatched by other cardiac imaging modalities. PMID:24509619

  6. Hepato-cardiac disorders

    PubMed Central

    Fouad, Yasser Mahrous; Yehia, Reem

    2014-01-01

    Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases PMID:24653793

  7. Advanced Cardiac Life Support.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document contains materials for an advanced college course in cardiac life support developed for the State of Iowa. The course syllabus lists the course title, hours, number, description, prerequisites, learning activities, instructional units, required text, six references, evaluation criteria, course objectives by units, course…

  8. Bezoar-induced small bowel obstruction: Clinical characteristics and diagnostic value of multi-slice spiral computed tomography

    PubMed Central

    Wang, Pei-Yuan; Wang, Xia; Zhang, Lin; Li, Hai-Fei; Chen, Liang; Wang, Xu; Wang, Bin

    2015-01-01

    AIM: To determine the possible predisposing factors of bezoar-induced small bowel obstruction (BI-SBO) and to discuss the diagnostic value of multi-slice spiral computed tomography, particularly contrast-enhanced scanning, in this condition. METHODS: A total of 35 BI-SBO cases treated at our hospital from January 2007 to December 2013 were retrospectively analysed. Complete clinical and computed tomography (CT) data of the patients were available and confirmed by surgery. SBO was clinically diagnosed on the basis of clinical manifestations. Of the 35 patients, 18 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT and 17 underwent abdominal and pelvic CT planar scanning with GE 64-slice spiral CT combined with contrast-enhanced examination. Original images were processed using a GE ADW4.3 workstation to obtain MPR, CPR, MIP and CTA images. The images of all patients were evaluated by two abdominal imaging experts. The main analytical contents of planar scanning included intestinal bezoar conditions, changes in the intestinal wall and changes in peri-intestinal conditions. Vascular hyperaemia and arterial blood supply conditions at a specific obstruction site and the distal end of the obstruction site were evaluated through contrast-enhanced examination. RESULTS: The proportion of males to females among the 35 cases was 1:1.69 (13:22); median age was 63.3 years. The following cases were observed: 29 (82.8%) cases occurred in autumn and winter and showed a history of consuming high amounts of persimmon and hawthorn; 19 (54.3%) cases revealed a history of gastrointestinal surgery; 19 exhibited incomplete dentition, with missing partial or whole posterior teeth; 26 suffered from obstruction at the ileum. A total of 51 bezoars were found in these patients, of whom 16 (45.7%) had multiple bezoars. CT planar scanning of bezoars showed lumps with mottled gas inside the intestinal cavity. Furthermore, 9 cases of bezoars had envelopes and 11 cases

  9. Ethical Issues in Cardiac Surgery

    PubMed Central

    Kavarana, Minoo N.; Sade, Robert M.

    2012-01-01

    While ethical behavior has always been part of cardiac surgical practice, ethical deliberation has only recently become an important component of cardiac surgical practice. Issues such as informed consent, conflict of interest, and professional self-regulation, among many others, have increasingly attracted the attention of cardiac surgeons. This review covers several broad topics of interest to cardiac surgeons and cardiologists, and treats several other topics more briefly. There is much uncertainty about what the future holds for cardiac surgical practice, research, and culture, and we discuss the background of ethical issues to serve as a platform for envisioning what is to come. PMID:22642634

  10. A Case of Infantile Cardiac Rhabdomyoma Complicated by Tuberous Sclerosis

    PubMed Central

    Serikawa, Takehiro; Takahashi, Yasuhiro; Kikuchi, Akira; Takakuwa, Koichi; Usuda, Tohei; Hasegawa, Satoshi; Tanaka, Kenichi

    2010-01-01

    We experienced a case with fetal cardiac tumor, which was diagnosed by prenatal ultrasonographic examination, and the diagnosis was confirmed after birth. A pregnancy woman of the 26th week of gestation was referred to our hospital for close examinations of fetal cardiac tumor. Ultrasonographic examinations revealed single homogeneous tumor with the diameter of 14 mm intracardiac space. The tumor was considered to emerge from the ventricular septum and to be occupied in left ventricle. Other cardiac abnormalities were not detected. The fetus was diagnosed to be complicated with the intracardiac tumor, and with the possible rhabdomyoma of heart. The serial ultrasonographic examinations revealed that the fetal cardiac function was normal. The size of the tumor gradually increased, although the fetal cardiac function revealed within normal range. The patient delivered a female infant weighing 2716g with the Apgar score of 9 and 10 at one and 5 minutes after delivery. The infant was confirmed to have cardiac tumors after examination by pediatric cardiologist, and the cardiac function of the infant was diagnosed as normal condition. The computed tomography of the head revealed the intracranial multiple calcification lesions, which indicated the symptoms of tuberous sclerosis.

  11. System for the diagnosis and monitoring of coronary artery disease, acute coronary syndromes, cardiomyopathy and other cardiac conditions

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T. (Inventor); Arenare, Brian (Inventor)

    2008-01-01

    Cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed and stored in a useful form using a computer. The computer monitor displays various useful information, and in particular graphically displays various permutations of reduced amplitude zones and kurtosis that increase the rapidity and accuracy of cardiac diagnoses. New criteria for reduced amplitude zones are defined that enhance the sensitivity and specificity for detecting cardiac abnormalities.

  12. Genetics of sudden cardiac death.

    PubMed

    Bezzina, Connie R; Lahrouchi, Najim; Priori, Silvia G

    2015-06-05

    Sudden cardiac death occurs in a broad spectrum of cardiac pathologies and is an important cause of mortality in the general population. Genetic studies conducted during the past 20 years have markedly illuminated the genetic basis of the inherited cardiac disorders associated with sudden cardiac death. Here, we review the genetic basis of sudden cardiac death with a focus on the current knowledge on the genetics of the primary electric disorders caused primarily by mutations in genes encoding ion channels, and the cardiomyopathies, which have been attributed to mutations in genes encoding a broader category of proteins, including those of the sarcomere, the cytoskeleton, and desmosomes. We discuss the challenges currently faced in unraveling genetic factors that predispose to sudden cardiac death in the setting of sequela of coronary artery disease and present the genome-wide association studies conducted in recent years on electrocardiographic parameters, highlighting their potential in uncovering new biological insights into cardiac electric function.

  13. Symmetry of cardiac function assessment

    PubMed Central

    Bai, Xu-Fang; Ma, Amy X

    2016-01-01

    Both right and left ventricles are developed from two adjacent segments of the primary heart tube. Though they are different with regard to shape and power, they mirror each other in terms of behavior. This is the first level of symmetry in cardiac function assessment. Both cardiac muscle contraction and relaxation are active. This constructs the second level of symmetry in cardiac function assessment. Combination of the two levels will help to find some hidden indexes or approaches to evaluate cardiac function. In this article, four major indexes from echocardiography were analyzed under this principal, another seventeen indexes or measurement approaches came out of the shadow, which is very helpful in the assessment of cardiac function, especially for the right cardiac function and diastolic cardiac function. PMID:27582768

  14. Excitation wave propagation in a patterned multidomain cardiac tissue

    NASA Astrophysics Data System (ADS)

    Kudryashova, N. N.; Teplenin, A. S.; Orlova, Y. V.; Agladze, K. I.

    2015-06-01

    Electrospun fibrous mats are widely used in the contemporary cardiac tissue engineering as the substrates for growing cardiac cells. The substrate with chaotically oriented nanofibers leads to the growth of cardiac tissue with randomly oriented, but internally morphologically anisotropic clusters or domains. The domain structure affects the stability of the excitation propagation and we studied the stability of the propagating excitation waves versus the average size of the domains and the externally applied excitation rate. In an experimental model based on neonatal rat cardiac tissue monolayers, as well as in the computer simulations, we have found that an increase in domain sizes leads to the decrease in the critical stimulation frequencies, thus evidencing that larger domains are having a higher arrhythmogenic effect.

  15. Non-invasive Mapping of Cardiac Arrhythmias.

    PubMed

    Shah, Ashok; Hocini, Meleze; Haissaguerre, Michel; Jaïs, Pierre

    2015-08-01

    Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome).

  16. Associations Between Cardio-Ankle Vascular Index and Aortic Structure and Sclerosis Using Multidetector Computed Tomography.

    PubMed

    Horinaka, Shigeo; Yagi, Hiroshi; Fukushima, Hiromichi; Shibata, Yoshimasa; Takeshima, Hiroshi; Ishimitsu, Toshihiko

    2017-04-01

    Aortic pulse wave velocity (PWV) has been accepted as the gold standard for arterial stiffness measurement. However, PWV depends on blood pressure (BP). To eliminate the BP dependency of PWV, the cardio-ankle vascular index (CAVI) was developed. This study aimed to define the relationship between CAVI and aortic atherosclerosis or structure on multidetector computed tomography (MDCT). Patients with (n = 49) or without (n = 49) coronary artery disease were studied. The lumen and vessel diameters and wall thickness were calculated from the cross-sectional area at the pulmonary bifurcation level by 64-slice MDCT. The CAVI was measured within 3 days before MDCT. Multivariate analysis showed that the vessel diameter of the ascending and descending aorta on MDCT depends on age, body surface area, and diastolic BP. The CAVI significantly correlated with the vessel diameter ( r = .453) and wall thickness ( r = .387) of the thoracic descending aorta ( P < .001, respectively). The CAVI was an independent predictor of the descending aortic wall thickness on multiple stepwise regression analysis. These data suggest that CAVI, a simple index, is useful for evaluating thoracic aortic atherosclerosis.

  17. Mesothelial/monocytic incidental cardiac excrescences (cardiac MICE) associated with acute aortic dissection: a study of two cases

    PubMed Central

    Strecker, Thomas; Bertz, Simone; Wachter, David Lukas; Weyand, Michael; Agaimy, Abbas

    2015-01-01

    Acute aortic dissection is a life-threatening condition mainly caused by hypertension, atherosclerotic disease and other degenerative diseases of the connective tissue of the aortic wall. Mesothelial/monocytic incidental cardiac excrescences (cardiac MICE) is a rare benign reactive tumor-like lesion composed of admixture of histiocytes, mesothelial cells, and inflammatory cells set within a fibrinous meshwork without a vascular network or supporting stroma. Cardiac MICE occurring in association with aortic dissection is exceptionally rare (only one such case reported to date). We herein report on the surgical repair of two Stanford type A aortic dissections caused by idiopathic giant cell aortitis in a 66-year-old-woman and by atherosclerotic disease in a 58-year-old-man, respectively. In both cases, the dissections could be visualized via computed tomography. Histopathology showed cardiac incidental MICE within the external aortic wall near the pericardial surface which was confirmed by immunohistochemistry. PMID:26097568

  18. Analysis of Ventricular Function by Computed Tomography

    PubMed Central

    Rizvi, Asim; Deaño, Roderick C.; Bachman, Daniel P.; Xiong, Guanglei; Min, James K.; Truong, Quynh A.

    2014-01-01

    The assessment of ventricular function, cardiac chamber dimensions and ventricular mass is fundamental for clinical diagnosis, risk assessment, therapeutic decisions, and prognosis in patients with cardiac disease. Although cardiac computed tomography (CT) is a noninvasive imaging technique often used for the assessment of coronary artery disease, it can also be utilized to obtain important data about left and right ventricular function and morphology. In this review, we will discuss the clinical indications for the use of cardiac CT for ventricular analysis, review the evidence on the assessment of ventricular function compared to existing imaging modalities such cardiac MRI and echocardiography, provide a typical cardiac CT protocol for image acquisition and post-processing for ventricular analysis, and provide step-by-step instructions to acquire multiplanar cardiac views for ventricular assessment from the standard axial, coronal, and sagittal planes. Furthermore, both qualitative and quantitative assessments of ventricular function as well as sample reporting are detailed. PMID:25576407

  19. Cardiac arrhythmias in pregnancy.

    PubMed

    Knotts, Robert J; Garan, Hasan

    2014-08-01

    As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias.

  20. Practical cardiac auscultation.

    PubMed

    Shindler, Daniel M

    2007-01-01

    This article focuses on the practical use of the stethoscope. The art of the cardiac physical examination includes skillful auscultation. The article provides the author's personal approach to the patient for the purpose of best hearing, recognizing, and interpreting heart sounds and murmurs. It should be used as a brief introduction to the art of auscultation. This article also attempts to illustrate heart sounds and murmurs by using words and letters to phonate the sounds, and by presenting practical clinical examples where auscultation clearly influences cardiac diagnosis and treatment. The clinical sections attempt to go beyond what is available in standard textbooks by providing information and stethoscope techniques that are valuable and useful at the bedside.

  1. Cardiac nuclear medicine

    SciTech Connect

    Gerson, M.C.

    1987-01-01

    The book begins with a review of the radionuclide methods available for evaluating cardiac perfusion and function. The authors discuss planar and tomographic thallium myocardial imaging, first-pass and equilibrium radionuclide angiography, and imaging with infarct-avid tracers. Several common but more specialized procedures are then reviewed: nonogemetric measurement of left ventricular volume, phase (Fourier) analysis, stroke volume ratio, right ventricular function, and diastolic function. A separate chapter is devoted to drug interventions and in particular the use of radionuclide ventriculography to monitor doxorubicin toxicity and therapy of congestive heart failure. The subsequent chapters provide a comprehensive guide to test selection, accuracy, and results in acute myocardial infarction, in postmyocardial infarction, in chronic coronary artery disease, before and after medical or surgical revascularization, in valvular heart disease, in cardiomyopathies, and in cardiac trauma.

  2. The Role of Cardiac Side Population Cells in Cardiac Regeneration

    PubMed Central

    Yellamilli, Amritha; van Berlo, Jop H.

    2016-01-01

    The heart has a limited ability to regenerate. It is important to identify therapeutic strategies that enhance cardiac regeneration in order to replace cardiomyocytes lost during the progression of heart failure. Cardiac progenitor cells are interesting targets for new regenerative therapies because they are self-renewing, multipotent cells located in the heart. Cardiac side population cells (cSPCs), the first cardiac progenitor cells identified in the adult heart, have the ability to differentiate into cardiomyocytes, endothelial cells, smooth muscle cells, and fibroblasts. They become activated in response to cardiac injury and transplantation of cSPCs into the injured heart improves cardiac function. In this review, we will discuss the current literature on the progenitor cell properties and therapeutic potential of cSPCs. This body of work demonstrates the great promise cSPCs hold as targets for new regenerative strategies. PMID:27679798

  3. Mechanical cardiac assistance.

    PubMed

    Sezai, Y

    1998-08-01

    In our institute, we have intensively introduced both pulsatile and non-pulsatile mechanical cardiac assist devices, such as the pneumatic ventricular assist device (VAD) and percutaneous cardiopulmonary support (PCPS), using a centrifugal pump. From various kinds of clinical views, these cases were estimated and evaluated retrospectively according to the weaning results, long-term survival rate and cause of death. Based upon our experiences and clinical results, an alternate strategy of mechanical cardiac assistance for severe heart failure is suggested as follows. In the case of post-cardiotomy cardiogenic shock or low output syndrome, PCPS system should be applied firstly under intra-aortic balloon pumping (IABP) assist for a maximum of 2-3 days. If the native cardiac function does not recover and more long-term support is needed, several types of VAD, which are more powerful and durable devices should be introduced, according to end organ function and expected support duration. In order to obtain better clinical results, we have to select an appropriate device depending on the limited availability of supporting duration. Generally speaking, centrifugal pumps can support in short-term duration, while pulsatile devices cover the broad spectrum of the supporting period. Pneumatic VADs can cover short-term to long-term support up to a year, and electric VADs can cover over 1 year, and can be used as a bridge to heart transplantation.

  4. Cardiac surgery 2015 reviewed.

    PubMed

    Doenst, Torsten; Strüning, Constanze; Moschovas, Alexandros; Gonzalez-Lopez, David; Essa, Yasin; Kirov, Hristo; Diab, Mahmoud; Faerber, Gloria

    2016-10-01

    For the year 2015, almost 19,000 published references can be found in PubMed when entering the search term "cardiac surgery". The last year has been again characterized by lively discussions in the fields where classic cardiac surgery and modern interventional techniques overlap. Lacking evidence in the field of coronary revascularization with either percutaneous coronary intervention or bypass surgery has been added. As in the years before, CABG remains the gold standard for the revascularization of complex stable triple-vessel disease. Plenty of new information has been presented comparing the conventional to transcatheter aortic valve implantation (TAVI) demonstrating similar short- and mid-term outcomes at high and low risk, but even a survival advantage with transfemoral TAVI at intermediate risk. In addition, there were many relevant and interesting other contributions from the purely operative arena. This review article will summarize the most pertinent publications in the fields of coronary revascularization, surgical treatment of valve disease, heart failure (i.e., transplantation and ventricular assist devices), and aortic surgery. While the article does not have the expectation of being complete and cannot be free of individual interpretation, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.

  5. 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

  6. The Alberta Cardiac Access Collaborative: improving the cardiac patient journey.

    PubMed

    Blackadar, Robyn; Houle, Mishaela

    2009-01-01

    The Alberta Cardiac Access Collaborative (ACAC) is a joint initiative of Alberta's health system to improve access to adult cardiac services across the patient journey. ACAC has created new care delivery models and implemented best practices across Alberta in four streams across the continuum: heart attack, patient navigation, heart failure and arrhythmia. Emergency medical providers, nurses, primary care physicians, hospitals, cardiac specialists and clinicians are all working together to integrate services, bridge jurisdictions and geography with one aim--improving the patient journey for adults in need of cardiac care.

  7. Determination of cardiac size following space missions of different durations - The second manned Skylab mission

    NASA Technical Reports Server (NTRS)

    Nicogossian, A.; Hoffler, G. W.; Johnson, R. L.; Gowen, R. J.

    1976-01-01

    A simple method to estimate cardiac size from single frontal plane chest roentgenograms has been described. Pre- and postflight chest X-rays from Apollo 17, and Skylab 2 and 3 have been analyzed for changes in the cardiac silhouette size. The data obtained from the computed cardiothoracic areal ratios compared well with the clinical cardiothoracic diametral ratios (r = .86). Though an overall postflight decrease in cardiac size is evident, the mean difference was not statistically significant (n = 8). The individual decreases in the cardiac silhouette size postflight are thought to be due to decrements in intracardiac chamber volumes rather than in myocardial muscle mass.

  8. An interleukin-6-producing cardiac myxoma associated with mediastinal lymphadenopathy.

    PubMed

    Takizawa, T; Sumino, H; Kanda, T; Kobayashi, I; Nagai, R; Ichikawa, S

    1999-01-01

    We report our experience with a patient whose mediastinal lymphadenopathy resolved after resection of a cardiac myxoma that secreted interleukin-6 (IL-6). The patient was a 68-year-old female who complained of nocturnal chest discomfort related to congestive heart failure. An echocardiogram demonstrated a large left atrial mass. A computed tomogram showed not only the left atrial mass but multiple enlarged mediastinal lymph nodes. The serum IL-6 level was markedly elevated at 13.7 pg/ml. After resection of the cardiac myxoma, serum IL-6 returned to the normal range. A repeat computed tomogram showed no mediastinal lymphadenopathy. We believe that overproduction of IL-6 by the cardiac myxoma was the cause of the mediastinal lymphadenopathy.

  9. Cardiac Emergencies in Neurosurgical Patients

    PubMed Central

    Petropolis, Andrea; Cappellani, Ronald B.

    2015-01-01

    Perioperative safety concerns are a major area of interest in recent years. Severe cardiac perturbation such as cardiac arrest is one of the most dreaded complications in the intraoperative period; however, little is known about the management of these events in the patients undergoing elective neurosurgery. This special group needs further attention, as it is often neither feasible nor appropriate to apply conventional advanced cardiac life support algorithms in patients undergoing neurosurgery. Factors such as neurosurgical procedure and positioning can also have a significant effect on the occurrence of cardiac arrest. Therefore, the aim of this paper is to describe the various causes and management of cardiac emergencies with special reference to cardiac arrest during elective neurosurgical procedures, including discussion of position-related factors and resuscitative considerations in these situations. This will help to formulate possible guidelines for management of such events. PMID:25692145

  10. Sudden Cardiac Death in Athletes

    PubMed Central

    Wasfy, Meagan M.; Hutter, Adolph M.; Weiner, Rory B.

    2016-01-01

    There are clear health benefits to exercise; even so, patients with cardiac conditions who engage in exercise and athletic competition may on rare occasion experience sudden cardiac death (SCD). This article reviews the epidemiology and common causes of SCD in specific athlete populations. There is ongoing debate about the optimal mechanism for SCD prevention, specifically regarding the inclusion of the ECG and/or cardiac imaging in routine preparticipation sports evaluation. This controversy and contemporary screening recommendations are also reviewed. PMID:27486488

  11. Registry of Unexplained Cardiac Arrest

    ClinicalTrials.gov

    2016-05-16

    Cardiac Arrest; Long QT Syndrome; Brugada Syndrome; Catecholaminergi Polymorphic Ventricular Tachycardia; Idiopathic VentricularFibrillation; Early Repolarization Syndrome; Arrhythmogenic Right Ventricular Cardiomyopathy

  12. Cardiac risk stratification and protection.

    PubMed

    Halub, Meghan E; Sidwell, Richard A

    2015-04-01

    The goal of preoperative cardiac evaluation is to screen for undiagnosed cardiac disease or to find evidence of known conditions that are poorly controlled to allow management that reduces the risk of perioperative cardiac complications. A careful history and physical examination combined with the procedure-specific risk is the cornerstone of this assessment. This article reviews a brief history of prior cardiac risk stratification indexes, explores current practice guidelines by the American College of Cardiology and the American Heart Association Task Force, reviews current methods for preoperative evaluation, discusses revascularization options, and evaluates perioperative medication recommendations.

  13. Cardiac surgery for Kartagener syndrome.

    PubMed

    Tkebuchava, T; von Segesser, L K; Niederhäuser, U; Bauersfeld, U; Turina, M

    1997-01-01

    Two patients (one girl, one boy) with Kartagener syndrome (situs inversus, bronchiectasis, sinusitis), despite pulmonary problems and associated congenital cardiac anomalies, were operated on at the ages of 4 years and 7 years, respectively. They had had previous palliative treatment at the age of 3 months and 1.3 years, respectively. Both postoperative periods after total correction were without significant complications. Long-term follow-up was available for 9 and 19 years, respectively, with no manifestations of heart insufficiency. Both patients are physically active, and neither requires cardiac medication. Patients with Kartagener syndrome and associated congenital cardiac anomalies can successfully undergo multiple cardiac operations with good long-term outcome.

  14. Cardiac Dysautonomia in Huntington's Disease.

    PubMed

    Abildtrup, Mads; Shattock, Michael

    2013-01-01

    Huntington's disease is a fatal, hereditary, neurodegenerative disorder best known for its clinical triad of progressive motor impairment, cognitive deficits and psychiatric disturbances. Although a disease of the central nervous system, mortality surveys indicate that heart disease is a leading cause of death. The nature of such cardiac abnormalities remains unknown. Clinical findings indicate a high prevalence of autonomic nervous system dysfunction - dysautonomia - which may be a result of pathology of the central autonomic network. Dysautonomia can have profound effects on cardiac health, and pronounced autonomic dysfunction can be associated with neurogenic arrhythmias and sudden cardiac death. Significant advances in the knowledge of neural mechanisms in cardiac disease have recently been made which further aid our understanding of cardiac mortality in Huntington's disease. Even so, despite the evidence of aberrant autonomic activity the potential cardiac consequences of autonomic dysfunction have been somewhat ignored. In fact, underlying cardiac abnormalities such as arrhythmias have been part of the exclusion criteria in clinical autonomic Huntington's disease research. A comprehensive analysis of cardiac function in Huntington's disease patients is warranted. Further experimental and clinical studies are needed to clarify how the autonomic nervous system is controlled and regulated in higher, central areas of the brain - and how these regions may be altered in neurological pathology, such as Huntington's disease. Ultimately, research will hopefully result in an improvement of management with the aim of preventing early death in Huntington's disease from cardiac causes.

  15. Computed Tomography Imaging in Patients with Congenital Heart Disease Part I: Rationale and Utility. An Expert Consensus Document of the Society of Cardiovascular Computed Tomography (SCCT): Endorsed by the Society of Pediatric Radiology (SPR) and the North American Society of Cardiac Imaging (NASCI).

    PubMed

    Han, B Kelly; Rigsby, Cynthia K; Hlavacek, Anthony; Leipsic, Jonathon; Nicol, Edward D; Siegel, Marilyn J; Bardo, Dianna; Abbara, Suhny; Ghoshhajra, Brian; Lesser, John R; Raman, Subha; Crean, Andrew M

    2015-01-01

    This is an expert consensus document created to provide information about the current use of cardiovascular computed tomography (CT) in patients of all ages with proven or suspected congenital heart disease (CHD). The discussion and recommendations are based on available literature and the judgment of a diverse group of subspecialists with extensive experience in the use of CT imaging in CHD. The field of CHD CT imaging is evolving rapidly with the availability of new scanner technology. In addition, the prevalence of palliated CHD has increased with marked improvements in patient survival. We believe it is important to review the clinical indications, strengths, limitations, and risks of cardiovascular CT in this patient population. This is the first of two complementary documents. It will concentrate on the disease entities and circumstances in which CT may be used. The second document will focus on recommendations for the technical performance of cardiovascular CT in patients with CHD. Successful cardiovascular CT imaging of CHD requires an in depth understanding of the core teaching elements of both cardiology and radiology. The ability to perform and interpret high quality congenital cardiovascular CT in a clinical context requires focused time and effort regardless of the previous background of the cardiac imager. This is reflected by a writing committee that consists of pediatric and adult radiologists and cardiologists, all whom have extensive experience in performing CT in this patient population. Cardiovascular CT is complementary to other imaging modalities and its optimal use will be in centers where all diagnostic modalities are available. The choice of modality for an individual patient should be determined by age, diagnosis, clinical condition, clinical question and patient preference.(1-4) Use of CT in CHD should be reserved for situations in which it is expected to provide unique diagnostic information for the individual patient or clinical

  16. Patient radiation biological risk in computed tomography angiography procedure.

    PubMed

    Alkhorayef, M; Babikir, E; Alrushoud, A; Al-Mohammed, H; Sulieman, A

    2017-02-01

    Computed tomography angiography (CTA) has become the most valuable imaging modality for the diagnosis of blood vessel diseases; however, patients are exposed to high radiation doses and the probability of cancer and other biological effects is increased. The objectives of this study were to measure the patient radiation dose during a CTA procedure and to estimate the radiation dose and biological effects. The study was conducted in two radiology departments equipped with 64-slice CT machines (Aquilion) calibrated according to international protocols. A total of 152 patients underwent brain, lower limb, chest, abdomen, and pelvis examinations. The effective radiation dose was estimated using ImPACT scan software. Cancer and biological risks were estimated using the International Commission on Radiological Protection (ICRP) conversion factors. The mean patient dose value per procedure (dose length product [DLP], mGy·cm) for all examinations was 437.8 ± 166, 568.8 ± 194, 516.0 ± 228, 581.8 ± 175, and 1082.9 ± 290 for the lower limbs, pelvis, abdomen, chest, and cerebral, respectively. The lens of the eye, uterus, and ovaries received high radiation doses compared to thyroid and testis. The overall patient risk per CTA procedure ranged between 15 and 36 cancer risks per 1 million procedures. Patient risk from CTA procedures is high during neck and abdomen procedures. Special concern should be provided to the lens of the eye and thyroid during brain CTA procedures. Patient dose reduction is an important consideration; thus, staff should optimize the radiation dose during CTA procedures.

  17. [Cardiac rehabilitation in women].

    PubMed

    Ghannem, M; Ghannem, L; Lamouchi, S; Justin, K D; Meimoun, P; Ghannem, L

    2016-12-01

    Coronary artery disease (CAD) occurs later in life in women when compared to men (10 years later). The FAST-MI study has shown that the profile of women with CAD has changed in the past 15 years, they are younger, more obese, and usually smokers. Whatever the age at which CAD occurs in women, the prognosis tends to be worse than in men, despite a higher frequency of acute coronary syndrome (ACS) with angiographically normal coronary arteries in women. In women without significant lesion at coronary angiography, the WISE study has shown abnormalities of the coronary vasomotricy. Despite its beneficial effect on morbidity and mortality, cardiac rehabilitation is underused particularly in women. Indeed, several factors do not encourage a woman to follow a cardiac rehabilitation program, even after an ACS. These factors may be cultural, domestic, familial, orthopedic, or even the fear of exercising. Therefore, physicians have to be particularly convincing in women, in order to have them participating in rehabilitation programs. Physical capacity is lower in women when compared to men. However, the weaker the physical capacity, the better the benefit of cardiac rehabilitation. Physical endurance training continuously or in interval, associated to muscle strengthening can improve the physical capacity in women. Vascular risk factors correction is also an important step for the management of women with CAD. Therapeutic education and several available workshops help women to better understand their disease and to improve their self-management when they return home. Anxiety, depression, and sexual dysfunction frequently deteriorate the quality of life of our patients. Therefore, psychological management is also essential in our departments.

  18. Dipyridamole cardiac imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Askenase, A.; Segal, B.L.; Auerbach, N.

    1988-02-01

    Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

  19. Cardiac Rehabilitation: MedlinePlus Health Topic

    MedlinePlus

    ... exercising are other risk factors. NIH: National Heart, Lung, and Blood Institute Start Here Cardiac Rehabilitation (Mayo Foundation for Medical Education and Research) Cardiac Rehabilitation (National Heart, Lung, and Blood Institute) What Is Cardiac Rehabilitation? (American Heart Association) - ...

  20. Microwave Treatment for Cardiac Arrhythmias

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Raffoul, George W. (Inventor); Pacifico, Antonio (Inventor)

    1999-01-01

    Method and apparatus are provided for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue to treat ventricular tachycardia and other arrhythmias while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In operation, microwave energy between about 1 Gigahertz and 12 Gigahertz is applied to monopole microwave radiator having a surface wave limiter. A test setup provides physical testing of microwave radiators to determine the temperature profile created in actual heart tissue or ersatz heart tissue. Saline solution pumped over the heart tissue with a peristaltic pump simulates blood flow. Optical temperature sensors disposed at various tissue depths within the heart tissue detect the temperature profile without creating any electromagnetic interference. The method may be used to produce a desired temperature profile in other body tissues reachable by catheter such as tumors and the like.

  1. Microwave Treatment for Cardiac Arrhythmias

    NASA Technical Reports Server (NTRS)

    Hernandez-Moya, Sonia

    2009-01-01

    NASA seeks to transfer the NASA developed microwave ablation technology, designed for the treatment of ventricular tachycardia (irregular heart beat), to industry. After a heart attack, many cells surrounding the resulting scar continue to live but are abnormal electrically; they may conduct impulses unusually slowly or fire when they would typically be silent. These diseased areas might disturb smooth signaling by forming a reentrant circuit in the muscle. The objective of microwave ablation is to heat and kill these diseased cells to restore appropriate electrical activity in the heart. This technology is a method and apparatus that provides for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In comparison with other methods that involve direct-current pulses or radio frequencies below 1 GHz, this method may prove more effective in treating ventricular tachycardia. This is because the present method provides for greater control of the location, cross-sectional area, and depth of a lesion via selection of the location and design of the antenna and the choice of microwave power and frequency.

  2. New Developments in Cardiac Regeneration.

    PubMed

    Le, Thi Yen Loan; Thavapalachandran, Sujitha; Kizana, Eddy; Chong, James Jh

    2017-04-01

    Numerous pharmacological and device therapies have improved adverse cardiac remodelling and mortality in heart failure. However, none are able to regenerate damaged cardiac tissue. Stem cell based therapies using multipotent (adult) stem cells and pluripotent stem cells are new approaches that could potentially achieve the elusive goal of true cardiac regeneration. Over the past two decades, various stem cell based approaches have been shown to improve left ventricular function in pre-clinical animal models. Promising results rapidly led to clinical trials, initially using bone marrow-derived mononuclear cells, then mesenchymal stromal cell populations and, more recently, progenitor cells from the adult heart itself. These have been shown to be safe and have advanced our understanding of potential suitable recipients, cell delivery routes, and possible mechanisms of action. However, efficacy in these trials has been inconsistent. Human pluripotent stem cells (hPSCs) are another potential source of stem cells for cardiac regeneration. They could theoretically provide an unlimited source of cardiomyocytes or cardiac progenitors. Pre-clinical studies in both small and large animal models have shown robust engraftment and improvements in cardiac function. The first clinical trial using hPSC-derived cardiac derivatives has now commenced and others are imminent. In this brief review article, we summarise recent developments in stem cell therapies aimed at cardiac regeneration, including discussion of types of cell and non-cell-based strategies being explored.

  3. Health Instruction Packages: Cardiac Anatomy.

    ERIC Educational Resources Information Center

    Phillips, Gwen; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

  4. Mitochondrial biogenesis in cardiac pathophysiology.

    PubMed

    Rimbaud, Stéphanie; Garnier, Anne; Ventura-Clapier, Renée

    2009-01-01

    Cardiac performance depends on a fine balance between the work the heart has to perform to satisfy the needs of the body and the energy that it is able to produce. Thus, energy production by oxidative metabolism, the main energy source of the cardiac muscle, has to be strictly regulated to adapt to cardiac work. Mitochondrial biogenesis is the mechanism responsible for mitochondrial component synthesis and assembly. This process controls mitochondrial content and thus correlates with energy production that, in turn, sustains cardiac contractility. Mitochondrial biogenesis should be finely controlled to match cardiac growth and cardiac work. When the heart is subjected to an increase in work in response to physiological and pathological challenges, it adapts by increasing its mass and expressing a new genetic program. In response to physiological stimuli such as endurance training, mitochondrial biogenesis seems to follow a program involving increased cardiac mass. But in the context of pathological hypertrophy, the modifications of this mechanism remain unclear. What appears clear is that mitochondrial biogenesis is altered in heart failure, and the imbalance between cardiac work demand and energy production represents a major factor in the development of heart failure.

  5. Redox Control of Cardiac Excitability

    PubMed Central

    Aggarwal, Nitin T.

    2013-01-01

    Abstract Reactive oxygen species (ROS) have been associated with various human diseases, and considerable attention has been paid to investigate their physiological effects. Various ROS are synthesized in the mitochondria and accumulate in the cytoplasm if the cellular antioxidant defense mechanism fails. The critical balance of this ROS synthesis and antioxidant defense systems is termed the redox system of the cell. Various cardiovascular diseases have also been affected by redox to different degrees. ROS have been indicated as both detrimental and protective, via different cellular pathways, for cardiac myocyte functions, electrophysiology, and pharmacology. Mostly, the ROS functions depend on the type and amount of ROS synthesized. While the literature clearly indicates ROS effects on cardiac contractility, their effects on cardiac excitability are relatively under appreciated. Cardiac excitability depends on the functions of various cardiac sarcolemal or mitochondrial ion channels carrying various depolarizing or repolarizing currents that also maintain cellular ionic homeostasis. ROS alter the functions of these ion channels to various degrees to determine excitability by affecting the cellular resting potential and the morphology of the cardiac action potential. Thus, redox balance regulates cardiac excitability, and under pathological regulation, may alter action potential propagation to cause arrhythmia. Understanding how redox affects cellular excitability may lead to potential prophylaxis or treatment for various arrhythmias. This review will focus on the studies of redox and cardiac excitation. Antioxid. Redox Signal. 18, 432–468. PMID:22897788

  6. GPCR signaling and cardiac function.

    PubMed

    Capote, Leany A; Mendez Perez, Roberto; Lymperopoulos, Anastasios

    2015-09-15

    G protein-coupled receptors (GPCRs), such as β-adrenergic and angiotensin II receptors, located in the membranes of all three major cardiac cell types, i.e. myocytes, fibroblasts and endothelial cells, play crucial roles in regulating cardiac function and morphology. Their importance in cardiac physiology and disease is reflected by the fact that, collectively, they represent the direct targets of over a third of the currently approved cardiovascular drugs used in clinical practice. Over the past few decades, advances in elucidation of their structure, function and the signaling pathways they elicit, specifically in the heart, have led to identification of an increasing number of new molecular targets for heart disease therapy. Here, we review these signaling modalities employed by GPCRs known to be expressed in the cardiac myocyte membranes and to directly modulate cardiac contractility. We also highlight drugs and drug classes that directly target these GPCRs to modulate cardiac function, as well as molecules involved in cardiac GPCR signaling that have the potential of becoming novel drug targets for modulation of cardiac function in the future.

  7. Revisiting Cardiac Cellular Composition

    PubMed Central

    Pinto, Alexander R.; Ilinykh, Alexei; Ivey, Malina J.; Kuwabara, Jill T.; D'Antoni, Michelle L.; Debuque, Ryan; Chandran, Anjana; Wang, Lina; Arora, Komal; Rosenthal, Nadia; Tallquist, Michelle D.

    2015-01-01

    Rationale Accurate knowledge of the cellular composition of the heart is essential to fully understand the changes that occur during pathogenesis and to devise strategies for tissue engineering and regeneration. Objective To examine the relative frequency of cardiac endothelial cells, hematopoietic-derived cells and fibroblasts in the mouse and human heart. Methods and Results Using a combination of genetic tools and cellular markers, we examined the occurrence of the most prominent cell types in the adult mouse heart. Immunohistochemistry revealed that endothelial cells constitute over 60%, hematopoietic-derived cells 5–10%, and fibroblasts under 20% of the non-myocytes in the heart. A refined cell isolation protocol and an improved flow cytometry approach provided an independent means of determining the relative abundance of non-myocytes. High dimensional analysis and unsupervised clustering of cell populations confirmed that endothelial cells are the most abundant cell population. Interestingly, fibroblast numbers are smaller than previously estimated, and two commonly assigned fibroblast markers, Sca-1 and CD90, underrepresent fibroblast numbers. We also describe an alternative fibroblast surface marker that more accurately identifies the resident cardiac fibroblast population. Conclusions This new perspective on the abundance of different cell types in the heart demonstrates that fibroblasts comprise a relatively minor population. By contrast, endothelial cells constitute the majority of non-cardiomyocytes and are likely to play a greater role in physiologic function and response to injury than previously appreciated. PMID:26635390

  8. Leadership in cardiac surgery.

    PubMed

    Rao, Christopher; Patel, Vanash; Ibrahim, Michael; Ahmed, Kamran; Wong, Kathie A; Darzi, Ara; von Segesser, Ludwig K; Athanasiou, Thanos

    2011-06-01

    Despite the efficacy of cardiac surgery, less invasive interventions with more uncertain long-term outcomes are increasingly challenging surgery as first-line treatment for several congenital, degenerative and ischemic cardiac diseases. The specialty must evolve if it is to ensure its future relevance. More importantly, it must evolve to ensure that future patients have access to treatments with proven long-term effectiveness. This cannot be achieved without dynamic leadership; however, our contention is that this is not enough. The demands of a modern surgical career and the importance of the task at hand are such that the serendipitous emergence of traditional charismatic leadership cannot be relied upon to deliver necessary change. We advocate systematic analysis and strategic leadership at a local, national and international level in four key areas: Clinical Care, Research, Education and Training, and Stakeholder Engagement. While we anticipate that exceptional individuals will continue to shape the future of our specialty, the creation of robust structures to deliver collective leadership in these key areas is of paramount importance.

  9. Decoding the Cardiac Message

    PubMed Central

    Dorn, Gerald W

    2012-01-01

    This review reflects and expands upon the contents of the author’s presentation at The Thomas W. Smith Memorial Lecture at AHA Scientific Sessions, 2011. “Decoding the cardiac message” refers to accumulating results from ongoing microRNA research that is altering longstanding concepts of the mechanisms for, and consequences of, messenger RNA (mRNA) regulation in the heart. First, I provide a brief historical perspective of the field of molecular genetics, touching upon seminal research that paved the way for modern molecular cardiovascular research and helped establish the foundation for current concepts of mRNA regulation in the heart. I follow with some interesting details about the specific research that led to the discovery and appreciation of microRNAs as highly conserved pivotal regulators of RNA expression and translation. Finally, I provide a personal viewpoint as to how agnostic genome-wide techniques for measuring microRNAs, their mRNA targets, and their protein products can be applied in an integrated multi-systems approach to uncover direct and indirect effects of microRNAs. Experimental designs integrating next-generation sequencing and global proteomics have the potential to address unanswered questions regarding microRNA-mRNA interactions in cardiac disease, how disease alters mRNA targeting by specific microRNAs, and how mutational and polymorphic nucleotide variation in microRNAs can affect end-organ function and stress-response. PMID:22383710

  10. Cardiac rehabilitation in Germany.

    PubMed

    Cantwell, J D

    1976-09-01

    The concept of cardiac reconditioning centers for the prevention and rehabilitation of coronary patients has been tremendously successful in Germany over the past 20 years. At least 40 such centers are located throughout the country. Physicians, nurses, and physical therapists work closely together in the various facets of the rehabilitation process. The financial backing for these facilities is primarily through governmental and regional insurance companies, whose officials are apparently convinced that in the long run supporting preventive measures is financially sound. Objective data supporting their convictions come from studies such as that of Brusis, who showed that such as that of 1,500 employees was diminished by nearly 70 percent during a two-year period after cardiac reconditioning, as compared to a similar time period before the rehabilitation experience. Subjective benefits, which are extremely difficult to quantitate in meaningful terms, were nonetheless expressed by nearly all the patients with whom I conversed. Perhaps they have experienced the same feelings that Mark Twain did when he observed that "all frets and worries and chafings sank to sleep in the presence of the benignant serenity of the Alps; the Great Spirit of the Mountains breathed his own peace upon their hurt minds and sore hearts and healed them."

  11. THE CHEMOTHERAPY OF CARDIAC ARREST.

    PubMed

    MINUCK, M

    1965-01-02

    Direct-air ventilation, external cardiac compression, and external defibrillation are established techniques for patients who unexpectedly develop cardiac arrest. The proper use of drugs can increase the incidence of successful resuscitation. Intracardiac adrenaline (epinephrine) acts as a powerful stimulant during cardiac standstill and, in addition, converts fine ventricular fibrillation to a coarser type, more responsive to electrical defibrillation. Routine use of intravenous sodium bicarbonate is recommended to combat the severe metabolic acidosis accompanying cardiac arrest. Lidocaine is particularly useful when ventricular fibrillation or ventricular tachycardia tends to recur. Analeptics are contraindicated, since they invariably increase oxygen requirements of already hypoxic cerebral tissues. The following acrostic is a useful mnemonic for recalling the details of the management of cardiac arrest in their proper order: A (Airway), B (Breathing), C (Circulation), D (Diagnosis of underlying cause), E (Epinephrine), F (Fibrillation), G (Glucose intravenously), pH (Sodium bicarbonate), I (Intensive care).

  12. Pediatric cardiac surgery in Indonesia.

    PubMed

    Asou, T; Rachmat, J

    1998-10-01

    Pediatric cardiac surgery in Indonesia first developed thanks to the cooperation of various cardiac centers abroad. The establishment of the 'Harapan Kita' National Cardiac Center in 1985 was one of the most important initial steps. Thereafter, the discipline advanced remarkably in terms of the number of the operations performed and the variety of the diseases treated and, as a result, the surgical outcome also improved. Numerous problems remain to be solved. Only 1% of the children with congenital heart disease are today properly treated in Indonesia. Some of the underlying problems responsible for this situation include a shortage of pediatric cardiac professionals, the lack of the information and education on the part of the patients, and a shortage of funding, both privately and publicly. It would thus be welcome for pediatric cardiac surgeons, cardiologists and nurses in Indonesia to learn about congenital heart disease from doctors and nurses in advanced countries in order to improve the outlook at home.

  13. Cardiac rehabilitation after myocardial infarction.

    PubMed

    Contractor, Aashish S

    2011-12-01

    Cardiac rehabilitation/secondary prevention programs are recognized as integral to the comprehensive care of patients with coronary heart disease (CHD), and as such are recommended as useful and effective (Class I) by the American Heart Association and the American College of Cardiology in the treatment of patients with CHD. The term cardiac rehabilitation refers to coordinated, multifaceted interventions designed to optimize a cardiac patient's physical, psychological, and social functioning, in addition to stabilizing, slowing, or even reversing the progression of the underlying atherosclerotic processes, thereby reducing morbidity and mortality. Cardiac rehabilitation, aims at returning the patient back to normal functioning in a safe and effective manner and to enhance the psychosocial and vocational state of the patient. The program involves education, exercise, risk factor modification and counselling. A meta-analysis based on a review of 48 randomized trials that compared outcomes of exercise-based rehabilitation with usual medical care, showed a reduction of 20% in total mortality and 26% in cardiac mortality rates, with exercise-based rehabilitation compared with usual medical care. Risk stratification helps identify patients who are at increased risk for exercise-related cardiovascular events and who may require more intensive cardiac monitoring in addition to the medical supervision provided for all cardiac rehabilitation program participants. During exercise, the patients' ECG is continuously monitored through telemetry, which serves to optimize the exercise prescription and enhance safety. The safety of cardiac rehabilitation exercise programs is well established, and the occurrence of major cardiovascular events during supervised exercise is extremely low. As hospital stays decrease, cardiac rehabilitation is assuming an increasingly important role in secondary prevention. In contrast with its growing importance internationally, there are very few

  14. Direct cone-beam cardiac reconstruction algorithm with cardiac banding artifact correction

    SciTech Connect

    Taguchi, Katsuyuki; Chiang, Beshan S.; Hein, Ilmar A.

    2006-02-15

    Multislice helical computed tomography (CT) is a promising noninvasive technique for coronary artery imaging. Various factors can cause inconsistencies in cardiac CT data, which can result in degraded image quality. These inconsistencies may be the result of the patient physiology (e.g., heart rate variations), the nature of the data (e.g., cone-angle), or the reconstruction algorithm itself. An algorithm which provides the best temporal resolution for each slice, for example, often provides suboptimal image quality for the entire volume since the cardiac temporal resolution (TRc) changes from slice to slice. Such variations in TRc can generate strong banding artifacts in multi-planar reconstruction images or three-dimensional images. Discontinuous heart walls and coronary arteries may compromise the accuracy of the diagnosis. A {beta}-blocker is often used to reduce and stabilize patients' heart rate but cannot eliminate the variation. In order to obtain robust and optimal image quality, a software solution that increases the temporal resolution and decreases the effect of heart rate is highly desirable. This paper proposes an ECG-correlated direct cone-beam reconstruction algorithm (TCOT-EGR) with cardiac banding artifact correction (CBC) and disconnected projections redundancy compensation technique (DIRECT). First the theory and analytical model of the cardiac temporal resolution is outlined. Next, the performance of the proposed algorithms is evaluated by using computer simulations as well as patient data. It will be shown that the proposed algorithms enhance the robustness of the image quality against inconsistencies by guaranteeing smooth transition of heart cycles used in reconstruction.

  15. Verification of cardiac tissue electrophysiology simulators using an N-version benchmark

    PubMed Central

    Niederer, Steven A.; Kerfoot, Eric; Benson, Alan P.; Bernabeu, Miguel O.; Bernus, Olivier; Bradley, Chris; Cherry, Elizabeth M.; Clayton, Richard; Fenton, Flavio H.; Garny, Alan; Heidenreich, Elvio; Land, Sander; Maleckar, Mary; Pathmanathan, Pras; Plank, Gernot; Rodríguez, José F.; Roy, Ishani; Sachse, Frank B.; Seemann, Gunnar; Skavhaug, Ola; Smith, Nic P.

    2011-01-01

    Ongoing developments in cardiac modelling have resulted, in particular, in the development of advanced and increasingly complex computational frameworks for simulating cardiac tissue electrophysiology. The goal of these simulations is often to represent the detailed physiology and pathologies of the heart using codes that exploit the computational potential of high-performance computing architectures. These developments have rapidly progressed the simulation capacity of cardiac virtual physiological human style models; however, they have also made it increasingly challenging to verify that a given code provides a faithful representation of the purported governing equations and corresponding solution techniques. This study provides the first cardiac tissue electrophysiology simulation benchmark to allow these codes to be verified. The benchmark was successfully evaluated on 11 simulation platforms to generate a consensus gold-standard converged solution. The benchmark definition in combination with the gold-standard solution can now be used to verify new simulation codes and numerical methods in the future. PMID:21969679

  16. Biophotonic Modelling of Cardiac Optical Imaging.

    PubMed

    Bishop, Martin J; Plank, Gernot

    2015-01-01

    Computational models have been recently applied to simulate and better understand the nature of fluorescent photon scattering and optical signal distortion during cardiac optical imaging. The goal of such models is both to provide a useful post-processing tool to facilitate a more accurate and faithful comparison between computational simulations of electrical activity and experiments, as well as providing essential insight into the mechanisms underlying this distortion, suggesting ways in which it may be controlled or indeed utilised to maximise the information derived from the recorded fluorescent signal. Here, we present different modelling methodologies developed and used in the field to simulate both the explicit processes involved in optical signal synthesis and the resulting consequences of the effects of photon scattering within the myocardium upon the optically-detected signal. We focus our attentions to two main types of modelling approaches used to simulate light transport in cardiac tissue, specifically continuous (reaction-diffusion) and discrete stochastic (Monte Carlo) methods. For each method, we provide both a summary of the necessary methodological details of such models, in addition to brief reviews of relevant application studies which have sought to apply these methods to elucidate important information regarding experimentally-recorded optical signals under different circumstances.

  17. [Thrombolysis in cardiac arrest].

    PubMed

    Ruiz Bailén, M; Rucabado Aguilar, L; Morante Valle, A; Castillo Rivera, A

    2006-03-01

    Both acute myocardial infarction and pulmonary thromboembolism are responsible for a great number of cardiac arrests. Both present high rates of mortality. Thrombolysis has proved to be an effective treatment for acute myocardial infarction and pulmonary thromboembolism with shock. It would be worth considering whether thrombolysis could be effective and safe during or after cardiopulmonary resuscitation (CPR). Unfortunately, too few clinical studies presenting sufficient scientific data exist in order to respond adequately to this question. However, most studies they show that thrombolysis applied during and after CPR is a therapeutic option that is not associated with greater risk of serious hemorrhaging and could possibly have beneficial effects. On the other hand, experimental data exists which show that thrombolytics can attenuate neurological damage produced after CPR. Nevertheless, clinical trials would be necessary in order to adequately establish the effectiveness and safety of thrombolysis in patients who require CPR.

  18. Cardiac action potential imaging

    NASA Astrophysics Data System (ADS)

    Tian, Qinghai; Lipp, Peter; Kaestner, Lars

    2013-06-01

    Action potentials in cardiac myocytes have durations in the order of magnitude of 100 milliseconds. In biomedical investigations the documentation of the occurrence of action potentials is often not sufficient, but a recording of the shape of an action potential allows a functional estimation of several molecular players. Therefore a temporal resolution of around 500 images per second is compulsory. In the past such measurements have been performed with photometric approaches limiting the measurement to one cell at a time. In contrast, imaging allows reading out several cells at a time with additional spatial information. Recent developments in camera technologies allow the acquisition with the required speed and sensitivity. We performed action potential imaging on isolated adult cardiomyocytes of guinea pigs utilizing the fluorescent membrane potential sensor di-8-ANEPPS and latest electron-multiplication CCD as well as scientific CMOS cameras of several manufacturers. Furthermore, we characterized the signal to noise ratio of action potential signals of varying sets of cameras, dye concentrations and objective lenses. We ensured that di-8-ANEPPS itself did not alter action potentials by avoiding concentrations above 5 μM. Based on these results we can conclude that imaging is a reliable method to read out action potentials. Compared to conventional current-clamp experiments, this optical approach allows a much higher throughput and due to its contact free concept leaving the cell to a much higher degree undisturbed. Action potential imaging based on isolated adult cardiomyocytes can be utilized in pharmacological cardiac safety screens bearing numerous advantages over approaches based on heterologous expression of hERG channels in cell lines.

  19. Trends in Cardiac Pacemaker Batteries

    PubMed Central

    Mallela, Venkateswara Sarma; Ilankumaran, V; Rao, N.Srinivasa

    2004-01-01

    Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future. PMID:16943934

  20. Spirituality and Autonomic Cardiac Control

    PubMed Central

    Berntson, Gary G.; Norman, Greg J.; Hawkley, Louise C.; Cacioppo, John T.

    2009-01-01

    Background Spirituality has been suggested to be associated with positive health, but potential biological mediators have not been well characterized. Purpose and Methods The present study examined, in a population based sample of middle-aged and older adults, the potential relationship between spirituality and patterns of cardiac autonomic control, which may have health significance. Measures of parasympathetic (high-frequency heart rate variability) and sympathetic (pre-ejection period) cardiac control were obtained from a representative sample of 229 participants. Participants completed questionnaires to assess spirituality (closeness to and satisfactory relation with God). Personality, demographic, anthropometric, health behavior, and health status information was also obtained. A series of multivariate regression models was used to examine the relations between spirituality, the autonomic measures, and two derived indexes-- cardiac autonomic balance (CAB, reflecting parasympathetic to sympathetic balance) and cardiac autonomic regulation (CAR, reflecting total autonomic control). Results Spirituality, net of demographics or other variables, was found to be associated with enhanced parasympathetic as well as sympathetic cardiac control (yielding a higher CAR); but was not associated with CAB. Although the number of cases was small (N=11), both spirituality and CAR were significant negative predictors of the prior occurrence of a myocardial infarction. Conclusions In a population based sample, spirituality appears to be associated with a specific pattern of cardiac autonomic regulation, characterized by a high level of cardiac autonomic control, irrespective of the relative contribution of the two autonomic branches. This pattern of autonomic control may have health significance. PMID:18357497

  1. Evaluation of cardiac emboli source

    PubMed Central

    Michels, M.; Meijboom, F.J.; ten Cate, F.J.

    2005-01-01

    Background Evaluating the source of cardiac embolism is one of the most frequent reasons for cardiac consultation. Methods In 2003, 99 patients were referred for the evaluation of the source of cardiac emboli. Evaluation included history, physical examination, ECG, transoesophageal echocardiography (TOE) with contrast and 24-hour Holter electrocardiography. Results Altogether, 58 men and 41 women were studied. In 32 patients a possible source of the cardiac emboli was found. Two patients were in atrial fibrillation. Of the patients, 16 had a patent foramen ovale (PFO) and six patients a PFO and atrial septum aneurysm (ASA). Two patients had a thrombus in the left atrial appendage and 14 had severe atherosclerosis in the aortic arch. In eight patients we found two possible cardiac sources of embolism. 24-hour Holter recording did not detect any emboligenic arrhythmias. Conclusion A possible cardiac source of embolism was found in 32% of the patients referred. TOE is the ideal tool to visualise the interatrial septum, left atrial appendage and aortic arch. We advise performing a TOE with contrast in young stroke patients and in older patients with a stroke likely to be caused by an embolism of cardiac origin. 24-hour Holter recording did not detect any emboligenic arrhythmias and should only be done in selected cases. ImagesFigure 1Figure 2 PMID:25696441

  2. Trends in cardiac pacemaker batteries.

    PubMed

    Mallela, Venkateswara Sarma; Ilankumaran, V; Rao, N Srinivasa

    2004-10-01

    Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future.

  3. Pharmacology of cardiac potassium channels.

    PubMed

    Tamargo, Juan; Caballero, Ricardo; Gómez, Ricardo; Valenzuela, Carmen; Delpón, Eva

    2004-04-01

    Cardiac K+ channels are membrane-spanning proteins that allow the passive movement of K+ ions across the cell membrane along its electrochemical gradient. They regulate the resting membrane potential, the frequency of pacemaker cells and the shape and duration of the cardiac action potential. Additionally, they have been recognized as potential targets for the actions of neurotransmitters and hormones and class III antiarrhythmic drugs that prolong the action potential duration (APD) and refractoriness and have been found effective to prevent/suppress cardiac arrhythmias. In the human heart, K+ channels include voltage-gated channels, such as the rapidly activating and inactivating transient outward current (Ito1), the ultrarapid (IKur), rapid (IKr) and slow (IKs) components of the delayed rectifier current and the inward rectifier current (IK1), the ligand-gated channels, including the adenosine triphosphate-sensitive (IKATP) and the acetylcholine-activated (IKAch) currents and the leak channels. Changes in the expression of K+ channels explain the regional variations in the morphology and duration of the cardiac action potential among different cardiac regions and are influenced by heart rate, intracellular signalling pathways, drugs and cardiovascular disorders. A progressive number of cardiac and noncardiac drugs block cardiac K+ channels and can cause a marked prolongation of the action potential duration (i.e. an acquired long QT syndrome, LQTS) and a distinct polymorphic ventricular tachycardia termed torsades de pointes. In addition, mutations in the genes encoding IKr (KCNH2/KCNE2) and IKs (KCNQ1/KCNE1) channels have been identified in some types of the congenital long QT syndrome. This review concentrates on the function, molecular determinants, regulation and, particularly, on the mechanism of action of drugs modulating the K+ channels present in the sarcolemma of human cardiac myocytes that contribute to the different phases of the cardiac action

  4. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a

  5. Acupuncture therapy related cardiac injury.

    PubMed

    Li, Xue-feng; Wang, Xian

    2013-12-01

    Cardiac injury is the most serious adverse event in acupuncture therapy. The causes include needling chest points near the heart, the cardiac enlargement and pericardial effusion that will enlarge the projected area on the body surface and make the proper depth of needling shorter, and the incorrect needling method of the points. Therefore, acupuncture practitioners must be familiar with the points of the heart projected area on the chest and the correct needling methods in order to reduce the risk of acupuncture therapy related cardiac injury.

  6. Cardiac Involvement in Ankylosing Spondylitis

    PubMed Central

    Ozkan, Yasemin

    2016-01-01

    Ankylosing spondylitis is one of the subgroup of diseases called “seronegative spondyloarthropathy”. Frequently, it affects the vertebral colon and sacroiliac joint primarily and affects the peripheral joints less often. This chronic, inflammatory and rheumatic disease can also affect the extraarticular regions of the body. The extraarticular affections can be ophthalmologic, cardiac, pulmonary or neurologic. The cardiac affection can be 2-10% in all patients. Cardiac complications such as left ventricular dysfunction, aortitis, aortic regurgitation, pericarditis and cardiomegaly are reviewed. PMID:27222669

  7. Echocardiography as an indication of continuous-time cardiac quiescence

    NASA Astrophysics Data System (ADS)

    Wick, C. A.; Auffermann, W. F.; Shah, A. J.; Inan, O. T.; Bhatti, P. T.; Tridandapani, S.

    2016-07-01

    Cardiac computed tomography (CT) angiography using prospective gating requires that data be acquired during intervals of minimal cardiac motion to obtain diagnostic images of the coronary vessels free of motion artifacts. This work is intended to assess B-mode echocardiography as a continuous-time indication of these quiescent periods to determine if echocardiography can be used as a cost-efficient, non-ionizing modality to develop new prospective gating techniques for cardiac CT. These new prospective gating approaches will not be based on echocardiography itself but on CT-compatible modalities derived from the mechanics of the heart (e.g. seismocardiography and impedance cardiography), unlike the current standard electrocardiogram. To this end, echocardiography and retrospectively-gated CT data were obtained from ten patients with varied cardiac conditions. CT reconstructions were made throughout the cardiac cycle. Motion of the interventricular septum (IVS) was calculated from both echocardiography and CT reconstructions using correlation-based, deviation techniques. The IVS was chosen because it (1) is visible in echocardiography images, whereas the coronary vessels generally are not, and (2) has been shown to be a suitable indicator of cardiac quiescence. Quiescent phases were calculated as the minima of IVS motion and CT volumes were reconstructed for these phases. The diagnostic quality of the CT reconstructions from phases calculated from echocardiography and CT data was graded on a four-point Likert scale by a board-certified radiologist fellowship-trained in cardiothoracic radiology. Using a Wilcoxon signed-rank test, no significant difference in the diagnostic quality of the coronary vessels was found between CT volumes reconstructed from echocardiography- and CT-selected phases. Additionally, there was a correlation of 0.956 between the echocardiography- and CT-selected phases. This initial work suggests that B-mode echocardiography can be used as a

  8. Normal cardiac function in mice with supraphysiological cardiac creatine levels.

    PubMed

    Santacruz, Lucia; Hernandez, Alejandro; Nienaber, Jeffrey; Mishra, Rajashree; Pinilla, Miguel; Burchette, James; Mao, Lan; Rockman, Howard A; Jacobs, Danny O

    2014-02-01

    Creatine and phosphocreatine levels are decreased in heart failure, and reductions in myocellular phosphocreatine levels predict the severity of the disease and portend adverse outcomes. Previous studies of transgenic mouse models with increased creatine content higher than two times baseline showed the development of heart failure and shortened lifespan. Given phosphocreatine's role in buffering ATP content, we tested the hypothesis whether elevated cardiac creatine content would alter cardiac function under normal physiological conditions. Here, we report the creation of transgenic mice that overexpress the human creatine transporter (CrT) in cardiac muscle under the control of the α-myosin heavy chain promoter. Cardiac transgene expression was quantified by qRT-PCR, and human CrT protein expression was documented on Western blots and immunohistochemistry using a specific anti-CrT antibody. High-energy phosphate metabolites and cardiac function were measured in transgenic animals and compared with age-matched, wild-type controls. Adult transgenic animals showed increases of 5.7- and 4.7-fold in the content of creatine and free ADP, respectively. Phosphocreatine and ATP levels were two times as high in young transgenic animals but declined to control levels by the time the animals reached 8 wk of age. Transgenic mice appeared to be healthy and had normal life spans. Cardiac morphometry, conscious echocardiography, and pressure-volume loop studies demonstrated mild hypertrophy but normal function. Based on our characterization of the human CrT protein expression, creatine and phosphocreatine content, and cardiac morphometry and function, these transgenic mice provide an in vivo model for examining the therapeutic value of elevated creatine content for cardiac pathologies.

  9. Use of cardiac biomarkers in neonatology.

    PubMed

    Vijlbrief, Daniel C; Benders, Manon J N L; Kemperman, Hans; van Bel, Frank; de Vries, Willem B

    2012-10-01

    Cardiac biomarkers are used to identify cardiac disease in term and preterm infants. This review discusses the roles of natriuretic peptides and cardiac troponins. Natriuretic peptide levels are elevated during atrial strain (atrial natriuretic peptide (ANP)) or ventricular strain (B-type natriuretic peptide (BNP)). These markers correspond well with cardiac function and can be used to identify cardiac disease. Cardiac troponins are used to assess cardiomyocyte compromise. Affected cardiomyocytes release troponin into the bloodstream, resulting in elevated levels of cardiac troponin. Cardiac biomarkers are being increasingly incorporated into clinical trials as indicators of myocardial strain. Furthermore, cardiac biomarkers can possibly be used to guide therapy and improve outcome. Natriuretic peptides and cardiac troponins are potential tools in the diagnosis and treatment of neonatal disease that is complicated by circulatory compromise. However, clear reference ranges need to be set and validation needs to be carried out in a population of interest.

  10. Hierarchical approaches for systems modeling in cardiac development.

    PubMed

    Gould, Russell A; Aboulmouna, Lina M; Varner, Jeffrey D; Butcher, Jonathan T

    2013-01-01

    Ordered cardiac morphogenesis and function are essential for all vertebrate life. The heart begins as a simple contractile tube, but quickly grows and morphs into a multichambered pumping organ complete with valves, while maintaining regulation of blood flow and nutrient distribution. Though not identical, cardiac morphogenesis shares many molecular and morphological processes across vertebrate species. Quantitative data across multiple time and length scales have been gathered through decades of reductionist single variable analyses. These range from detailed molecular signaling pathways at the cellular levels to cardiac function at the tissue/organ levels. However, none of these components act in true isolation from others, and each, in turn, exhibits short- and long-range effects in both time and space. With the absence of a gene, entire signaling cascades and genetic profiles may be shifted, resulting in complex feedback mechanisms. Also taking into account local microenvironmental changes throughout development, it is apparent that a systems level approach is an essential resource to accelerate information generation concerning the functional relationships across multiple length scales (molecular data vs physiological function) and structural development. In this review, we discuss relevant in vivo and in vitro experimental approaches, compare different computational frameworks for systems modeling, and the latest information about systems modeling of cardiac development. Finally, we conclude with some important future directions for cardiac systems modeling.

  11. Conceptual Foundations of Systems Biology Explaining Complex Cardiac Diseases.

    PubMed

    Louridas, George E; Lourida, Katerina G

    2017-02-21

    Systems biology is an important concept that connects molecular biology and genomics with computing science, mathematics and engineering. An endeavor is made in this paper to associate basic conceptual ideas of systems biology with clinical medicine. Complex cardiac diseases are clinical phenotypes generated by integration of genetic, molecular and environmental factors. Basic concepts of systems biology like network construction, modular thinking, biological constraints (downward biological direction) and emergence (upward biological direction) could be applied to clinical medicine. Especially, in the field of cardiology, these concepts can be used to explain complex clinical cardiac phenotypes like chronic heart failure and coronary artery disease. Cardiac diseases are biological complex entities which like other biological phenomena can be explained by a systems biology approach. The above powerful biological tools of systems biology can explain robustness growth and stability during disease process from modulation to phenotype. The purpose of the present review paper is to implement systems biology strategy and incorporate some conceptual issues raised by this approach into the clinical field of complex cardiac diseases. Cardiac disease process and progression can be addressed by the holistic realistic approach of systems biology in order to define in better terms earlier diagnosis and more effective therapy.

  12. Right ventricle segmentation from cardiac MRI: a collation study.

    PubMed

    Petitjean, Caroline; Zuluaga, Maria A; Bai, Wenjia; Dacher, Jean-Nicolas; Grosgeorge, Damien; Caudron, Jérôme; Ruan, Su; Ayed, Ismail Ben; Cardoso, M Jorge; Chen, Hsiang-Chou; Jimenez-Carretero, Daniel; Ledesma-Carbayo, Maria J; Davatzikos, Christos; Doshi, Jimit; Erus, Guray; Maier, Oskar M O; Nambakhsh, Cyrus M S; Ou, Yangming; Ourselin, Sébastien; Peng, Chun-Wei; Peters, Nicholas S; Peters, Terry M; Rajchl, Martin; Rueckert, Daniel; Santos, Andres; Shi, Wenzhe; Wang, Ching-Wei; Wang, Haiyan; Yuan, Jing

    2015-01-01

    Magnetic Resonance Imaging (MRI), a reference examination for cardiac morphology and function in humans, allows to image the cardiac right ventricle (RV) with high spatial resolution. The segmentation of the RV is a difficult task due to the variable shape of the RV and its ill-defined borders in these images. The aim of this paper is to evaluate several RV segmentation algorithms on common data. More precisely, we report here the results of the Right Ventricle Segmentation Challenge (RVSC), concretized during the MICCAI'12 Conference with an on-site competition. Seven automated and semi-automated methods have been considered, along them three atlas-based methods, two prior based methods, and two prior-free, image-driven methods that make use of cardiac motion. The obtained contours were compared against a manual tracing by an expert cardiac radiologist, taken as a reference, using Dice metric and Hausdorff distance. We herein describe the cardiac data composed of 48 patients, the evaluation protocol and the results. Best results show that an average 80% Dice accuracy and a 1cm Hausdorff distance can be expected from semi-automated algorithms for this challenging task on the datasets, and that an automated algorithm can reach similar performance, at the expense of a high computational burden. Data are now publicly available and the website remains open for new submissions (http://www.litislab.eu/rvsc/).

  13. A model of electrical conduction in cardiac tissue including fibroblasts.

    PubMed

    Sachse, Frank B; Moreno, A P; Seemann, G; Abildskov, J A

    2009-05-01

    Fibroblasts are abundant in cardiac tissue. Experimental studies suggested that fibroblasts are electrically coupled to myocytes and this coupling can impact cardiac electrophysiology. In this work, we present a novel approach for mathematical modeling of electrical conduction in cardiac tissue composed of myocytes, fibroblasts, and the extracellular space. The model is an extension of established cardiac bidomain models, which include a description of intra-myocyte and extracellular conductivities, currents and potentials in addition to transmembrane voltages of myocytes. Our extension added a description of fibroblasts, which are electrically coupled with each other and with myocytes. We applied the extended model in exemplary computational simulations of plane waves and conduction in a thin tissue slice assuming an isotropic conductivity of the intra-fibroblast domain. In simulations of plane waves, increased myocyte-fibroblast coupling and fibroblast-myocyte ratio reduced peak voltage and maximal upstroke velocity of myocytes as well as amplitudes and maximal downstroke velocity of extracellular potentials. Simulations with the thin tissue slice showed that inter-fibroblast coupling affected rather transversal than longitudinal conduction velocity. Our results suggest that fibroblast coupling becomes relevant for small intra-myocyte and/or large intra-fibroblast conductivity. In summary, the study demonstrated the feasibility of the extended bidomain model and supports the hypothesis that fibroblasts contribute to cardiac electrophysiology in various manners.

  14. Conceptual Foundations of Systems Biology Explaining Complex Cardiac Diseases

    PubMed Central

    Louridas, George E.; Lourida, Katerina G.

    2017-01-01

    Systems biology is an important concept that connects molecular biology and genomics with computing science, mathematics and engineering. An endeavor is made in this paper to associate basic conceptual ideas of systems biology with clinical medicine. Complex cardiac diseases are clinical phenotypes generated by integration of genetic, molecular and environmental factors. Basic concepts of systems biology like network construction, modular thinking, biological constraints (downward biological direction) and emergence (upward biological direction) could be applied to clinical medicine. Especially, in the field of cardiology, these concepts can be used to explain complex clinical cardiac phenotypes like chronic heart failure and coronary artery disease. Cardiac diseases are biological complex entities which like other biological phenomena can be explained by a systems biology approach. The above powerful biological tools of systems biology can explain robustness growth and stability during disease process from modulation to phenotype. The purpose of the present review paper is to implement systems biology strategy and incorporate some conceptual issues raised by this approach into the clinical field of complex cardiac diseases. Cardiac disease process and progression can be addressed by the holistic realistic approach of systems biology in order to define in better terms earlier diagnosis and more effective therapy. PMID:28230815

  15. Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

    PubMed Central

    2013-01-01

    Background Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780). Methods/Design The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest

  16. Radiation from Cardiac Imaging Tests

    MedlinePlus

    ... thought you would like to see the Circulation web site. Your Personal Message Send Message Share on Social Media Radiation From Cardiac Imaging Tests Andrew J. Einstein Circulation. 2013; 127: e495-e497 , ...

  17. Mitochondrial Dysfunction in Cardiac Ageing

    PubMed Central

    Tocchi, Autumn; Quarles, Ellen K.; Basisty, Nathan; Gitari, Lemuel; Rabinovitch, Peter S.

    2015-01-01

    Cardiovascular diseases are the leading cause of death in most developed nations. While it has received the least public attention, aging is the dominant risk factor for developing cardiovascular diseases, as the prevalence of cardiovascular diseases increases dramatically with increasing age. Cardiac aging is an intrinsic process that results in impaired cardiac function, along with cellular and molecular changes. Mitochondria play a great role in these processes, as cardiac function is an energetically demanding process. In this review, we examine mitochondrial dysfunction in cardiac aging. Recent research has demonstrated that mitochondrial dysfunction can disrupt morphology, signaling pathways, and protein interactions; conversely, mitochondrial homeostasis is maintained by mechanisms that include fission/fusion, autophagy, and unfolded protein responses. Finally, we describe some of the recent findings in mitochondrial targeted treatments to help meet the challenges of mitochondrial dysfunction in aging. PMID:26191650

  18. Cardiac transplantation in Friedreich ataxia.

    PubMed

    Yoon, Grace; Soman, Teesta; Wilson, Judith; George, Kristen; Mital, Seema; Dipchand, Anne I; McCabe, Jane; Logan, William; Kantor, Paul

    2012-09-01

    In this article, we describe a 14-year-old boy with a confirmed diagnosis of Friedreich ataxia who underwent cardiac transplantation for left ventricular failure secondary to dilated cardiomyopathy with restrictive physiology. His neurological status prior to transplantation reflected early signs of neurological disease, with evidence of dysarthria, weakness, mild gait impairment, and limb ataxia. We review the ethical issues considered during the process leading to the decision to offer cardiac transplantation.

  19. Cardiac output after burn injury.

    PubMed Central

    Porter, J. M.; Shakespeare, P. G.

    1984-01-01

    Cardiac output after burn injury has been measured by the non-invasive method of impedance plethysmography. An initial study of 143 normal subjects was undertaken in order to investigate variations in cardiac output with age. Fifteen patients were monitored during resuscitation after extensive burns. Fourteen patients showed a depression of stroke volume below the lower limits of the normal range, derived from the initial study on normal people. PMID:6691694

  20. Diuretics in cardiac edema--1969.

    PubMed

    Shanoff, H M

    1969-10-04

    New and powerful diuretics have made it possible for the physician to control cardiac edema in most patients. At the same time their potentially dangerous side effects make it mandatory for the physician to be knowledgeable and judicious in their use. The appreciation of a few simplified facts about cardiac edema and renal reabsorption of sodium makes the clinical pharmacology of the diuretics much easier to understand, remember and apply.

  1. Cardiac effects of noncardiac neoplasms

    SciTech Connect

    Schoen, F.J.; Berger, B.M.; Guerina, N.G.

    1984-11-01

    Clinically significant cardiovascular abnormalities may occur as secondary manifestations of noncardiac neoplasms. The principal cardiac effects of noncardiac tumors include the direct results of metastases to the heart or lungs, the indirect effects of circulating tumor products (causing nonbacterial thrombotic endocarditis, myeloma-associated amyloidosis, pheochromocytoma-associated cardiac hypertrophy and myofibrillar degeneration, and carcinoid heart disease), and the undesired cardiotoxicities of chemotherapy and radiotherapy. 89 references.

  2. Subtle alternating electrocardiographic morphology as an indicator of decreased cardiac electrical stability

    NASA Technical Reports Server (NTRS)

    Smith, J. M.; Blue, B.; Clancy, E.; Valeri, C. R.; Cohen, R. J.

    1985-01-01

    Observations from finite-element computer models, together with analytic developments based on percolation theory have suggested that subtle fluctuations of ECG morphology might serve as an indicator diminished cardiac electrical stability. With fixed-rate atrial pacing in canines, we have previously observed a pattern of alternation in T wave energy which correlated with cardiac electrical stability. We report here on a series of 20 canine experiments in which cardiac electrical stability (measured via Ventricular Fibrillation Threshold determination) was compared to a non-degenerate, multidimensional measurement of the degree of alternating activity present in the ECG complex morphology. The decrease in cardiac electrical stability brought on by both coronary artery occlusion and systemic hypothermia was consistently accompanied by subtle alternation in ECG morphology, with the absolute degree of alternating activity being significantly (negatively) correlated with cardiac electrical stability.

  3. Cardiac Regeneration and Stem Cells

    PubMed Central

    Zhang, Yiqiang; Mignone, John; MacLellan, W. Robb

    2015-01-01

    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world. PMID:26269526

  4. Simulations of Complex and Microscopic Models of Cardiac Electrophysiology Powered by Multi-GPU Platforms

    PubMed Central

    Gouvêa de Barros, Bruno; Sachetto Oliveira, Rafael; Meira, Wagner; Lobosco, Marcelo; Weber dos Santos, Rodrigo

    2012-01-01

    Key aspects of cardiac electrophysiology, such as slow conduction, conduction block, and saltatory effects have been the research topic of many studies since they are strongly related to cardiac arrhythmia, reentry, fibrillation, or defibrillation. However, to reproduce these phenomena the numerical models need to use subcellular discretization for the solution of the PDEs and nonuniform, heterogeneous tissue electric conductivity. Due to the high computational costs of simulations that reproduce the fine microstructure of cardiac tissue, previous studies have considered tissue experiments of small or moderate sizes and used simple cardiac cell models. In this paper, we develop a cardiac electrophysiology model that captures the microstructure of cardiac tissue by using a very fine spatial discretization (8 μm) and uses a very modern and complex cell model based on Markov chains for the characterization of ion channel's structure and dynamics. To cope with the computational challenges, the model was parallelized using a hybrid approach: cluster computing and GPGPUs (general-purpose computing on graphics processing units). Our parallel implementation of this model using a multi-GPU platform was able to reduce the execution times of the simulations from more than 6 days (on a single processor) to 21 minutes (on a small 8-node cluster equipped with 16 GPUs, i.e., 2 GPUs per node). PMID:23227109

  5. A telemetry system for the study of spontaneous cardiac arrhythmias.

    PubMed

    Rollins, D L; Killingsworth, C R; Walcott, G P; Justice, R K; Ideker, R E; Smith, W M

    2000-07-01

    The characteristics of spontaneous cardiac arrhythmias leading to sudden cardiac death are largely unknown. To study arrhythmias in animal models, an eight-channel implantable radio telemetry system has been developed to record continuously cardiac electrograms over a period of weeks to months, with maintenance restricted to changing batteries. The inputs are connected in a unipolar manner. Each channel has a gain of fifty and is AC coupled, band limited to 0.07-260 Hz. The signals are digitized with 12 bits resolution at 1000 samples/s. The amplifiers, analog-to-digital converter, and control logic are packaged in an implantable unit. An umbilical cable is passed through the skin to an external backpack unit for power and data transmission. A custom serial interface card, a PC/104 form factor 25-MHz 80386-based single-board computer with a PCMCIA wireless local area network (WLAN) card, and battery power supply make up the backpack. Data are read into the parallel port of the computer, buffered, then transmitted over the WLAN to the laboratory network where it can be analyzed and archived. Approximately 12 h of 14,000 bytes/s data can be collected with each set of batteries. The system is suitable for continuous monitoring of animal models of spontaneous arrhythmias and sudden cardiac death.

  6. Exploring cardiac biophysical properties.

    PubMed

    Ait Mou, Younss; Bollensdorff, Christian; Cazorla, Olivier; Magdi, Yacoub; de Tombe, Pieter P

    2015-01-01

    The heart is subject to multiple sources of stress. To maintain its normal function, and successfully overcome these stresses, heart muscle is equipped with fine-tuned regulatory mechanisms. Some of these mechanisms are inherent within the myocardium itself and are known as intrinsic mechanisms. Over a century ago, Otto Frank and Ernest Starling described an intrinsic mechanism by which the heart, even ex vivo, regulates its function on a beat-to-beat basis. According to this phenomenon, the higher the ventricular filling is, the bigger the stroke volume. Thus, the Frank-Starling law establishes a direct relationship between the diastolic and systolic function of the heart. To observe this biophysical phenomenon and to investigate it, technologic development has been a pre-requisite to scientific knowledge. It allowed for example to observe, at the cellular level, a Frank-Starling like mechanism and has been termed: Length Dependent Activation (LDA). In this review, we summarize some experimental systems that have been developed and are currently still in use to investigate cardiac biophysical properties from the whole heart down to the single myofibril. As a scientific support, investigation of the Frank-Starling mechanism will be used as a case study.

  7. Exploring cardiac biophysical properties

    PubMed Central

    Mou, Younss Ait; Bollensdorff, Christian; Cazorla, Olivier; Magdi, Yacoub; de Tombe, Pieter P.

    2015-01-01

    The heart is subject to multiple sources of stress. To maintain its normal function, and successfully overcome these stresses, heart muscle is equipped with fine-tuned regulatory mechanisms. Some of these mechanisms are inherent within the myocardium itself and are known as intrinsic mechanisms. Over a century ago, Otto Frank and Ernest Starling described an intrinsic mechanism by which the heart, even ex vivo, regulates its function on a beat-to-beat basis. According to this phenomenon, the higher the ventricular filling is, the bigger the stroke volume. Thus, the Frank-Starling law establishes a direct relationship between the diastolic and systolic function of the heart. To observe this biophysical phenomenon and to investigate it, technologic development has been a pre-requisite to scientific knowledge. It allowed for example to observe, at the cellular level, a Frank-Starling like mechanism and has been termed: Length Dependent Activation (LDA). In this review, we summarize some experimental systems that have been developed and are currently still in use to investigate cardiac biophysical properties from the whole heart down to the single myofibril. As a scientific support, investigation of the Frank-Starling mechanism will be used as a case study. PMID:26779498

  8. Cardiac Imaging System

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Although not available to all patients with narrowed arteries, balloon angioplasty has expanded dramatically since its introduction with an estimated further growth to 562,000 procedures in the U.S. alone by 1992. Growth has fueled demand for higher quality imaging systems that allow the cardiologist to be more accurate and increase the chances of a successful procedure. A major advance is the Digital Cardiac Imaging (DCI) System designed by Philips Medical Systems International, Best, The Netherlands and marketed in the U.S. by Philips Medical Systems North America Company. The key benefit is significantly improved real-time imaging and the ability to employ image enhancement techniques to bring out added details. Using a cordless control unit, the cardiologist can manipulate images to make immediate assessment, compare live x-ray and roadmap images by placing them side-by-side on monitor screens, or compare pre-procedure and post procedure conditions. The Philips DCI improves the cardiologist's precision by expanding the information available to him.

  9. Artifacts at Cardiac CT: Physics and Solutions.

    PubMed

    Kalisz, Kevin; Buethe, Ji; Saboo, Sachin S; Abbara, Suhny; Halliburton, Sandra; Rajiah, Prabhakar

    2016-01-01

    Computed tomography is vulnerable to a wide variety of artifacts, including patient- and technique-specific artifacts, some of which are unique to imaging of the heart. Motion is the most common source of artifacts and can be caused by patient, cardiac, or respiratory motion. Cardiac motion artifacts can be reduced by decreasing the heart rate and variability and the duration of data acquisition; adjusting the placement of the data window within a cardiac cycle; performing single-heartbeat scanning; and using multisegment reconstruction, motion-correction algorithms, and electrocardiographic editing. Respiratory motion artifacts can be minimized with proper breath holding and shortened scan duration. Partial volume averaging is caused by the averaging of attenuation values from all tissue contained within a voxel and can be reduced by improving the spatial resolution, using a higher x-ray energy, or displaying images with a wider window width. Beam-hardening artifacts are caused by the polyenergetic nature of the x-ray beam and can be reduced by using x-ray filtration, applying higher-energy x-rays, altering patient position, modifying contrast material protocols, and applying certain reconstruction algorithms. Metal artifacts are complex and have multiple causes, including x-ray scatter, underpenetration, motion, and attenuation values that exceed the typical dynamic range of Hounsfield units. Quantum mottle or noise is caused by insufficient penetration of tissue and can be improved by increasing the tube current or peak tube potential, reconstructing thicker sections, increasing the rotation time, using appropriate patient positioning, and applying iterative reconstruction algorithms. (©)RSNA, 2016.

  10. Cell-Specific Cardiac Electrophysiology Models

    PubMed Central

    Groenendaal, Willemijn; Ortega, Francis A.; Kherlopian, Armen R.; Zygmunt, Andrew C.; Krogh-Madsen, Trine; Christini, David J.

    2015-01-01

    The traditional cardiac model-building paradigm involves constructing a composite model using data collected from many cells. Equations are derived for each relevant cellular component (e.g., ion channel, exchanger) independently. After the equations for all components are combined to form the composite model, a subset of parameters is tuned, often arbitrarily and by hand, until the model output matches a target objective, such as an action potential. Unfortunately, such models often fail to accurately simulate behavior that is dynamically dissimilar (e.g., arrhythmia) to the simple target objective to which the model was fit. In this study, we develop a new approach in which data are collected via a series of complex electrophysiology protocols from single cardiac myocytes and then used to tune model parameters via a parallel fitting method known as a genetic algorithm (GA). The dynamical complexity of the electrophysiological data, which can only be fit by an automated method such as a GA, leads to more accurately parameterized models that can simulate rich cardiac dynamics. The feasibility of the method is first validated computationally, after which it is used to develop models of isolated guinea pig ventricular myocytes that simulate the electrophysiological dynamics significantly better than does a standard guinea pig model. In addition to improving model fidelity generally, this approach can be used to generate a cell-specific model. By so doing, the approach may be useful in applications ranging from studying the implications of cell-to-cell variability to the prediction of intersubject differences in response to pharmacological treatment. PMID:25928268

  11. ECPR for Refractory Out-Of-Hospital Cardiac Arrest

    ClinicalTrials.gov

    2017-02-22

    Cardiac Arrest; Heart Arrest; Sudden Cardiac Arrest; Cardiopulmonary Arrest; Death, Sudden, Cardiac; Cardiopulmonary Resuscitation; CPR; Extracorporeal Cardiopulmonary Resuscitation; Extracorporeal Membrane Oxygenation

  12. Automated segmentation of cardiac visceral fat in low-dose non-contrast chest CT images

    NASA Astrophysics Data System (ADS)

    Xie, Yiting; Liang, Mingzhu; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2015-03-01

    Cardiac visceral fat was segmented from low-dose non-contrast chest CT images using a fully automated method. Cardiac visceral fat is defined as the fatty tissues surrounding the heart region, enclosed by the lungs and posterior to the sternum. It is measured by constraining the heart region with an Anatomy Label Map that contains robust segmentations of the lungs and other major organs and estimating the fatty tissue within this region. The algorithm was evaluated on 124 low-dose and 223 standard-dose non-contrast chest CT scans from two public datasets. Based on visual inspection, 343 cases had good cardiac visceral fat segmentation. For quantitative evaluation, manual markings of cardiac visceral fat regions were made in 3 image slices for 45 low-dose scans and the Dice similarity coefficient (DSC) was computed. The automated algorithm achieved an average DSC of 0.93. Cardiac visceral fat volume (CVFV), heart region volume (HRV) and their ratio were computed for each case. The correlation between cardiac visceral fat measurement and coronary artery and aortic calcification was also evaluated. Results indicated the automated algorithm for measuring cardiac visceral fat volume may be an alternative method to the traditional manual assessment of thoracic region fat content in the assessment of cardiovascular disease risk.

  13. A New Parameter for Cardiac Efficiency Analysis

    NASA Astrophysics Data System (ADS)

    Borazjani, Iman; Rajan, Navaneetha Krishnan; Song, Zeying; Hoffmann, Kenneth; MacMahon, Eileen; Belohlavek, Marek

    2014-11-01

    Detecting and evaluating a heart with suboptimal pumping efficiency is a significant clinical goal. However, the routine parameters such as ejection fraction, quantified with current non-invasive techniques are not predictive of heart disease prognosis. Furthermore, they only represent left-ventricular (LV) ejection function and not the efficiency, which might be affected before apparent changes in the function. We propose a new parameter, called the hemodynamic efficiency (H-efficiency) and defined as the ratio of the useful to total power, for cardiac efficiency analysis. Our results indicate that the change in the shape/motion of the LV will change the pumping efficiency of the LV even if the ejection fraction is kept constant at 55% (normal value), i.e., H-efficiency can be used for suboptimal cardiac performance diagnosis. To apply H-efficiency on a patient-specific basis, we are developing a system that combines echocardiography (echo) and computational fluid dynamics (CFD) to provide the 3D pressure and velocity field to directly calculate the H-efficiency parameter. Because the method is based on clinically used 2D echo, which has faster acquisition time and lower cost relative to other imaging techniques, it can have a significant impact on a large number of patients. This work is partly supported by the American Heart Association.

  14. [Cardiac herniation and torsion after transpericardial pneumonectomy].

    PubMed

    Schummer, W; Hottenrott, A; Nissel, C

    2016-07-05

    This article presents the case of a 43 year old woman with right-sided lung cancer. She underwent transpericardial pneumonectomy. After an uneventfull surgery, the patient was transferred to the intensive care unit for postoperative monitoring. She was hemodynamically stable and had already been extubated in the OR.On postoperative chest X‑ray a mediastinal shift to the operated side as well as a herniation of the heart into the right chest cavity was detected. While the patient remained hemodynamically stable a computed tomography of the chest was performed which confirmed the diagnosis of cardiac herniation and torsion. The lady underwent rethoracotomy the following day where the heart was repositioned and the pericardial defect was closed. She made an uneventfull recovery.Five years after the pneumonectomy she remains well and is without relapse of lung cancer.Mechanism for cardiac herniation and torsion, the clinical presentation and the typical radiologic signs are discussed. However, the clue to early diagnosis is a high index of clinical suspicion.It is highlighted that a hemodynamically unstable patient under these circumstances demands urgent rethoracotomy.

  15. Techniques for efficient, real-time, 3D visualization of multi-modality cardiac data using consumer graphics hardware.

    PubMed

    Levin, David; Aladl, Usaf; Germano, Guido; Slomka, Piotr

    2005-09-01

    We exploit consumer graphics hardware to perform real-time processing and visualization of high-resolution, 4D cardiac data. We have implemented real-time, realistic volume rendering, interactive 4D motion segmentation of cardiac data, visualization of multi-modality cardiac data and 3D display of multiple series cardiac MRI. We show that an ATI Radeon 9700 Pro can render a 512x512x128 cardiac Computed Tomography (CT) study at 0.9 to 60 frames per second (fps) depending on rendering parameters and that 4D motion based segmentation can be performed in real-time. We conclude that real-time rendering and processing of cardiac data can be implemented on consumer graphics cards.

  16. Integrative Systems Models of Cardiac Excitation Contraction Coupling

    PubMed Central

    Greenstein, Joseph L.; Winslow, Raimond L.

    2010-01-01

    Excitation-contraction coupling in the cardiac myocyte is mediated by a number of highly integrated mechanisms of intracellular Ca2+ transport. The complexity and integrative nature of heart cell electrophysiology and Ca2+-cycling has led to an evolution of computational models that have played a crucial role in shaping our understanding of heart function. An important emerging theme in systems biology is that the detailed nature of local signaling events, such as those that occur in the cardiac dyad, have important consequences at higher biological scales. Multi-scale modeling techniques have revealed many mechanistic links between micro-scale events, such as Ca2+ binding to a channel protein, and macro-scale phenomena, such as excitation-contraction coupling gain. Here we review experimentally based multi-scale computational models of excitation-contraction coupling and the insights that have been gained through their application. PMID:21212390

  17. Direct Cardiac Reprogramming: From Developmental Biology to Cardiac Regeneration

    PubMed Central

    Qian, Li; Srivastava, Deepak

    2013-01-01

    Heart disease affects millions worldwide and is a progressive condition involving loss of cardiomyocytes. The human heart has limited endogenous regenerative capacity and is thus an important target for novel regenerative medicine approaches. While cell-based regenerative therapies hold promise, cellular reprogramming of endogenous cardiac fibroblasts, which represent more than half of the cells in the mammalian heart, may be an attractive alternative strategy for regenerating cardiac muscle. Recent advances leveraging years of developmental biology point to the feasibility of generating de novo cardiomyocyte-like cells from terminally differentiated non-myocytes in the heart in situ after ischemic damage. Here, we review the progress in cardiac reprogramming methods and consider the opportunities and challenges that lie ahead in refining this technology for regenerative medicine. PMID:24030021

  18. Sudden cardiac death: A reappraisal.

    PubMed

    Steinberg, Christian; Laksman, Zachary W M; Krahn, Andrew D

    2016-11-01

    Sudden cardiac death (SCD) is still among the leading causes of death in women and men, accounting for over 50% of all fatal cardiovascular events in the United States. Two arrhythmia mechanisms of SCD can be distinguished as follows: shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia) and non-shockable rhythms including asystole or pulseless electrical activity. The overall prognosis of cardiac arrest due to shockable rhythms is significantly better. While the majority of SCDs is attributed to coronary artery disease or other structural heart disease, no obvious cause can be identified in 5% of all events, and those events are labeled as sudden unexplained deaths (SUD). Those unexplained events are typically caused by rare hereditary electrical disorders or arrhythmogenic cardiomyopathies. A systematic approach to the diagnosis of cardiac arrest followed by tailored therapy based on etiology has emerged in the last 10-15 years, with significant changes of medical practice and risk management of cardiac arrest victims. The aim of this review is to summarize our contemporary understanding of SCD/SUD in adults and to discuss current concepts of management and secondary prevention in cardiac arrest victims. A full discussion of the topic of primary prevention of SCD is beyond the scope of this article.

  19. Pharmacology of cardiac potassium channels.

    PubMed

    Li, Gui-Rong; Dong, Ming-Qing

    2010-01-01

    Cardiac K(+) channels are cardiomyocyte membrane proteins that regulate K(+) ion flow across the cell membrane on the electrochemical gradient and determine the resting membrane potential and the cardiac action potential morphology and duration. Several K(+) channels have been well studied in the human heart. They include the transient outward K(+) current I(to1), the ultra-rapidly activating delayed rectifier current I(Kur), the rapidly and slowly activating delayed rectifier currents I(Kr) and I(Ks), the inward rectifier K(+) current I(K1), and ligand-gated K(+) channels, including adenosine-5'-triphosphate (ATP)-sensitive K(+) current (I(KATP)) and acetylcholine-activated current (I(KACh)). Regional differences of K(+) channel expression contribute to the variable morphologies and durations of cardiac action potentials from sinus node and atrial to ventricular myocytes, and different ventricular layers from endocardium and midmyocardium to epicardium. They also show different responses to endogenous regulators and/or pharmacological agents. K(+) channels are well-known targets for developing novel anti-arrhythmic drugs that can effectively prevent/inhibit cardiac arrhythmias. Especially, atrial-specific K(+) channel currents (I(Kur) and I(KACh)) are the targets for developing atrial-selective anti-atrial fibrillation drugs, which has been greatly progressed in recent years. This chapter concentrates on recent advances in intracellular signaling regulation and pharmacology of cardiac K(+) channels under physiological and pathophysiological conditions.

  20. [Cardiac surgery in the elderly].

    PubMed

    Wiegmann, B; Ismail, I; Haverich, A

    2017-02-01

    Due to the increasing demographic changes and the fact that cardiovascular diseases are still the leading cause of death, the mean chronological age of patients undergoing cardiac surgery is steadily increasing. In 2015, 14.8% of these patients were aged 80 years and older. This meta-analysis reviewed if and under what circumstances elderly patients benefit from cardiac surgical procedures without running the risk of limitations in the quality of life and high rates of morbidity and mortality. Generally, the chronological age was not a risk factor for higher perioperative and postoperative morbidity and mortality but the biological age was the critical factor, in particular the associated comorbidities of patients and the timing of the surgical procedure in the course of the disease. The result is that elective operations resulted in a better outcome than operations in a symptomatic or decompensated stage of a disease. Compared to patients receiving conventional medicinal therapy, elderly patients undergoing cardiac surgery had an improved life expectancy. A significant increase in the quality of life could also be identified and was ultimately comparable to those of younger patients after cardiac surgery; therefore, elderly patients even those over 80 years old benefit in all aspects of cardiac surgery, as long as individually adapted operative techniques are considered.

  1. A computerized system for localizing sources of cardiac activation.

    PubMed

    Salu, Y; Mehrotra, P

    1984-06-01

    A noninvasive method for locating a source of cardiac electrical activity is described. The data acquisition and its preliminary processing is done with the aid of a microcomputer, while lengthier calculations are done on a large computer. The method was tested on 18 patients, and the results indicate that it is reliable, and with further technical refinements it could be used in research and clinical settings.

  2. Quasiperiodicity and chaos in cardiac fibrillation.

    PubMed Central

    Garfinkel, A; Chen, P S; Walter, D O; Karagueuzian, H S; Kogan, B; Evans, S J; Karpoukhin, M; Hwang, C; Uchida, T; Gotoh, M; Nwasokwa, O; Sager, P; Weiss, J N

    1997-01-01

    In cardiac fibrillation, disorganized waves of electrical activity meander through the heart, and coherent contractile function is lost. We studied fibrillation in three stationary forms: in human chronic atrial fibrillation, in a stabilized form of canine ventricular fibrillation, and in fibrillation-like activity in thin sheets of canine and human ventricular tissue in vitro. We also created a computer model of fibrillation. In all four studies, evidence indicated that fibrillation arose through a quasiperiodic stage of period and amplitude modulation, thus exemplifying the "quasiperiodic transition to chaos" first suggested by Ruelle and Takens. This suggests that fibrillation is a form of spatio-temporal chaos, a finding that implies new therapeutic approaches. PMID:9005999

  3. Out-of-hospital Cardiac Arrest (OHCA) Biomarkers

    ClinicalTrials.gov

    2017-04-07

    Neurological Outcome; Cardiac Arrest; Out-Of-Hospital Cardiac Arrest; Brain Anoxia Ischemia; Hypoxia, Brain; Hypoxia-Ischemia, Brain; Cardiac Arrest With Successful Resuscitation; Cardiac Arrest, Out-Of-Hospital; Brain Injuries

  4. Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI.

    PubMed

    Lapa, Constantin; Reiter, Theresa; Kircher, Malte; Schirbel, Andreas; Werner, Rudolf A; Pelzer, Theo; Pizarro, Carmen; Skowasch, Dirk; Thomas, Lena; Schlesinger-Irsch, Ulrike; Thomas, Daniel; Bundschuh, Ralph A; Bauer, Wolfgang R; Gärtner, Florian C

    2016-11-22

    Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR-PET/CT for detecting cardiac sarcoidosis in comparison to CMR.15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUVmean) and maximum standardized uptake values (SUVmax) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity.SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET- subjects, one patient with minor involvement (<25% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET- patients displayed no adverse cardiac events during follow-up.In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1% (245/255 segments analyzed). SUVmean and SUVmax in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUVmean and 2.0±0.3 and 1.7±0.3 for SUVmax, respectively.Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series.

  5. Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI

    PubMed Central

    Kircher, Malte; Schirbel, Andreas; Werner, Rudolf A.; Pelzer, Theo; Pizarro, Carmen; Skowasch, Dirk; Thomas, Lena; Schlesinger-Irsch, Ulrike; Thomas, Daniel; Bundschuh, Ralph A.

    2016-01-01

    Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR–PET/CT for detecting cardiac sarcoidosis in comparison to CMR. 15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUVmean) and maximum standardized uptake values (SUVmax) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity. SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET− subjects, one patient with minor involvement (<25% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET− patients displayed no adverse cardiac events during follow-up. In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1% (245/255 segments analyzed). SUVmean and SUVmax in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUVmean and 2.0±0.3 and 1.7±0.3 for SUVmax, respectively. Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series. PMID:27780922

  6. Exercise-induced cardiac remodeling.

    PubMed

    Weiner, Rory B; Baggish, Aaron L

    2012-01-01

    Early investigations in the late 1890s and early 1900s documented cardiac enlargement in athletes with above-normal exercise capacity and no evidence of cardiovascular disease. Such findings have been reported for more than a century and continue to intrigue scientists and clinicians. It is well recognized that repetitive participation in vigorous physical exercise results in significant changes in myocardial structure and function. This process, termed exercise-induced cardiac remodeling (EICR), is characterized by structural cardiac changes including left ventricular hypertrophy with sport-specific geometry (eccentric vs concentric). Associated alterations in both systolic and diastolic functions are emerging as recognized components of EICR. The increasing popularity of recreational exercise and competitive athletics has led to a growing number of individuals exhibiting these findings in routine clinical practice. This review will provide an overview of EICR in athletes.

  7. [Ectopia cordis and cardiac anomalies].

    PubMed

    Cabrera, Alberto; Rodrigo, David; Luis, María Teresa; Pastor, Esteban; Galdeano, José Miguel; Esteban, Susana

    2002-11-01

    Ectopia cordis is a rare disease that occurs in 5.5 to 7.9 per million live births. Only 267 cases had been reported as of 2001, most (95%) associated with other cardiac anomalies. We studied the cardiac malformations associated in 6 patients with ectopia cordis. Depending on where the defect was located, the cases of ectopia were classified into four groups: cervical, thoracic, thoraco-abdominal, and abdominal. All 6 patients died before the third day of life, 4 during delivery. Three of the patients were included in the thoracic group, whereas the other 3 belonged to the thoraco-abdominal group. All the patients had associated ventricular septal defects, 3 double-outlet right ventricle (50%) and the rest (50%) tetralogy of Fallot-pulmonary atresia. Two patients with double-outlet right ventricle presented mitral-valve pathology, a parachute valve and an atresic mitral valve. None of these cardiac anomalies have been reported to date.

  8. Cardiac manifestations in Behcet's disease

    PubMed Central

    Demirelli, Selami; Degirmenci, Husnu; Inci, Sinan; Arisoy, Arif

    2015-01-01

    Summary Behcet's disease (BD) is a chronic inflammatory disorder, with vasculitis underlying the pathophysiology of its multisystemic effects. Venous pathology and thrombotic complications are hallmarks of BD. However, it has been increasingly recognised that cardiac involvement and arterial complications are also important aspects of the course of the disease. Cardiac lesions include pericarditis, endocarditis, intracardiac thrombosis, myocardial infarction, endomyocardial fibrosis, and myocardial aneurysm. Treatment of cardiovascular involvement in BD is largely empirical, and is aimed towards suppressing the vasculitis. The most challenging aspect seems to be the treatment of arterial aneurysms and thromboses due to the associated risk of bleeding. When the prognosis of cardiac involvement in BD is not good, recovery can be achieved through oral anticoagulation, immunosuppressive therapy, and colchicine use. In this review, we summarise the cardiovascular involvement, different manifestations, and treatment of BD. PMID:25984424

  9. Cardiac myofilaments: mechanics and regulation

    NASA Technical Reports Server (NTRS)

    de Tombe, Pieter P.; Bers, D. M. (Principal Investigator)

    2003-01-01

    The mechanical properties of the cardiac myofilament are an important determinant of pump function of the heart. This report is focused on the regulation of myofilament function in cardiac muscle. Calcium ions form the trigger that induces activation of the thin filament which, in turn, allows for cross-bridge formation, ATP hydrolysis, and force development. The structure and protein-protein interactions of the cardiac sarcomere that are responsible for these processes will be reviewed. The molecular mechanism that underlies myofilament activation is incompletely understood. Recent experimental approaches have been employed to unravel the mechanism and regulation of myofilament mechanics and energetics by activator calcium and sarcomere length, as well as contractile protein phosphorylation mediated by protein kinase A. Central to these studies is the question whether such factors impact on muscle function simply by altering thin filament activation state, or whether modulation of cross-bridge cycling also plays a part in the responses of muscle to these stimuli.

  10. Current trends in cardiac rehabilitation

    PubMed Central

    Dafoe, W; Huston, P

    1997-01-01

    Cardiac rehabilitation can reduce mortality and morbidity for patients with many types of cardiac disease cost-effectively, yet is generally underutilized. Rehabilitation is helpful not only for patients who have had a myocardial infarction but also for those with stable angina or congestive heart failure or those who have undergone myocardial revascularization procedures, a heart transplant or heart valve surgery. The beneficial effects of rehabilitation include a reduction in the rate of death from cardiovascular disease, improved exercise tolerance, fewer cardiac symptoms, improved lipid levels, decreased cigarette smoking, improvement in psychosocial well-being and increased likelihood of return to work. Rehabilitation involves a multidisciplinary team that focuses on education, individually tailored exercise, risk-factor modification and the optimization of functional status and mental health. Current research trends in this area include the evaluation of new secondary-prevention modalities and alternative program options, such as home-based rehabilitation. PMID:9054823

  11. Cardiac Fibrosis: The Fibroblast Awakens

    PubMed Central

    Travers, Joshua G.; Kamal, Fadia A.; Robbins, Jeffrey; Yutzey, Katherine E.; Blaxall, Burns C.

    2016-01-01

    Myocardial fibrosis is a significant global health problem associated with nearly all forms of heart disease. Cardiac fibroblasts comprise an essential cell type in the heart that is responsible for the homeostasis of the extracellular matrix; however upon injury, these cells transform to a myofibroblast phenotype and contribute to cardiac fibrosis. This remodeling involves pathological changes that include chamber dilation, cardiomyocyte hypertrophy and apoptosis, and ultimately leads to the progression to heart failure. Despite the critical importance of fibrosis in cardiovascular disease, our limited understanding of this cell population impedes the development of potential therapies that effectively target this cell type and its pathological contribution to disease progression. This review summarizes current knowledge regarding the origins and roles of fibroblasts, mediators and signaling pathways known to influence fibroblast function after myocardial injury, as well as novel therapeutic strategies under investigation to attenuate cardiac fibrosis. PMID:26987915

  12. Development of a cardiac evaluation method using a dynamic flat-panel detector (FPD) system: a feasibility study using a cardiac motion phantom.

    PubMed

    Tanaka, Rie; Sanada, Shigeru; Tsujioka, Katsumi; Matsui, Takeshi; Takata, Tadanori; Matsui, Osamu

    2008-01-01

    The purpose of this study is to investigate the feasibility of cardiac evaluation with a dynamic flat-panel detector (FPD), based on changes in pixel values during cardiac pumping. To investigate the feasibility of cardiac evaluation with a dynamic flat-panel detector (FPD), based on changes in pixel values during cardiac pumping. Sequential radiographs of a cardiac motion phantom and water-equivalent material step were obtained with an FPD system. Various combinations of cardiac output and heart rate were evaluated with and without contrast medium. The ventricular area and summation of pixel values in the ventricles were measured. The ejection fraction (EF) was calculated based on the rate of changes and then compared to EF obtained from computed tomography images. In addition, slight changes in pixel values were visualized by use of inter-frame subtraction and color-mapping. The result of a clinical case was examined according to cardiac physiology. There were strong correlations between EF and our results. There was no significant difference between the findings with and without contrast medium. When the heart rate was greater than 60 bpm, EF obtained with our method were underestimated. It is necessary for a patient to be examined at an imaging rate between 7.5 and 10 fps at least. In addition, a +/-1.2% change in pixel value was equivalent to a +/-10 mm change in the thickness of water. Color-mapping images were supported by cardiac physiology. Evaluating changes in pixel values on dynamic chest radiography with FPD has the potential to demonstrate cardiac function without contrast medium. Inter-frame subtraction and color-mapping are very useful for interpreting changes in pixel value as velocities of blood flow.

  13. Sudden Cardiac Arrest (SCA) Risk Assessment

    MedlinePlus

    ... HRS Find a Specialist Share Twitter Facebook SCA Risk Assessment Sudden Cardiac Arrest (SCA) occurs abruptly and without ... people of all ages and health conditions. Start Risk Assessment The Sudden Cardiac Arrest (SCA) Risk Assessment Tool ...

  14. MR and CT appearance of cardiac hemangioma

    SciTech Connect

    Kemp, J.L.; Kessler, R.M.; Raizada, V.; Williamson, M.R.

    1996-05-01

    We present a case of cardiac hemangioma in a symptomatic patient. MR and CT each have specific characteristics that should make one consider including or excluding this in the differential diagnosis of a cardiac tumor. 7 refs., 3 figs.

  15. Cardiac Arrest: MedlinePlus Health Topic

    MedlinePlus

    ... dying from a second SCA. NIH: National Heart, Lung, and Blood Institute Start Here About Cardiac Arrest (American Heart ... Society) What Is Sudden Cardiac Arrest? (National Heart, Lung, and Blood Institute) Latest News How Devices in Public Places ...

  16. A cardiac cause for deafness

    PubMed Central

    Naha, Kushal; Vivek, G; Shetty, Ranjan K; Dias, Lorraine Simone

    2013-01-01

    We describe a case of a 49-year-old diabetic man with a history of myocardial infarction, presenting with deafness for 2 weeks. Initial assessment by otorhinolaryngologists was suggestive of sensorineural hearing loss. Subsequently, the cardiac evaluation showed an apical clot in the left ventricle. Careful neurological reassessment and a cranial MRI yielded a diagnosis of cortical deafness with auditory agnosia secondary to bilateral temporal infarcts. Doppler and MRI ruled out carotid artery thrombosis. The temporal infarcts were therefore considered to be cardioembolic in origin. Cardioembolic stroke is an important differential diagnosis for patients presenting with neurological symptoms on a background of cardiac disease. PMID:24165506

  17. Redox regulation of cardiac hypertrophy.

    PubMed

    Sag, Can M; Santos, Celio X C; Shah, Ajay M

    2014-08-01

    It is increasingly evident that redox-dependent modifications in cellular proteins and signaling pathways (or redox signaling) play important roles in many aspects of cardiac hypertrophy. Indeed, these redox modifications may be intricately linked with the process of hypertrophy wherein there is not only a significant increase in myocardial O2 consumption but also important alterations in metabolic processes and in the local generation of O2-derived reactive species (ROS) that modulate and/or amplify cell signaling pathways. This article reviews our current knowledge of redox signaling pathways and their roles in cardiac hypertrophy. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".

  18. PGD for inherited cardiac diseases.

    PubMed

    Kuliev, Anver; Pomerantseva, Ekaterina; Polling, Dana; Verlinsky, Oleg; Rechitsky, Svetlana

    2012-04-01

    Preimplantation genetic diagnosis (PGD) has been applied for more than 200 different inherited conditions, with expanding application to common disorders with genetic predisposition. One of the recent indications for PGD has been inherited cardiac disease, for which no preclinical diagnosis and preventive management may exist and which may lead to premature or sudden death. This paper presents the first, as far as is known, cumulative experience of PGD for inherited cardiac diseases, including familial hypertrophic and dilated cardiomyopathy, cardioencephalomyopathy and Emery-Dreifuss muscular dystrophy. A total of 18 PGD cycles were performed, resulting in transfer in 15 of them, which yielded nine unaffected pregnancies and the births of seven disease- or disease predisposition-free children. The data open the prospect of PGD for inherited cardiac diseases, allowing couples carrying cardiac disease predisposing genes to reproduce without much fear of having offspring with these genes, which are at risk for premature or sudden death. Preimplantation genetic diagnosis (PGD) is currently an established clinical procedure in assisted reproduction and genetic practices. Its application has been expanding beyond traditional indications of prenatal diagnosis and currently includes common disorders with genetic predisposition, such as inherited forms of cancer. This applies also to the diseases with no current prospect of treatment, which may manifest despite presymptomatic diagnosis and follow up, when PGD may provide the only relief for the at-risk couples to reproduce. One of the recent indications for PGD has been inherited cardiac disease, for which no preclinical diagnosis and preventive management may exist and which may lead to premature or sudden death. We present here our first cumulative experience of PGD for inherited cardiac diseases, including familial hypertrophic and dilated cardiomyopathy, cardioencephalomyopathy and Emery-Dreifuss muscular dystrophy. A

  19. Neurological complications of cardiac surgery.

    PubMed

    McDonagh, David L; Berger, Miles; Mathew, Joseph P; Graffagnino, Carmelo; Milano, Carmelo A; Newman, Mark F

    2014-05-01

    As increasing numbers of elderly people undergo cardiac surgery, neurologists are frequently called upon to assess patients with neurological complications from the procedure. Some complications mandate acute intervention, whereas others need longer term observation and management. A large amount of published literature exists about these complications and guidance on best practice is constantly changing. Similarly, despite technological advances in surgical intervention and modifications in surgical technique to make cardiac procedures safer, these advances often create new avenues for neurological injury. Accordingly, rapid and precise neurological assessment and therapeutic intervention rests on a solid understanding of the evidence base and procedural variables.

  20. Cardiac 4D Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    D'hooge, Jan

    Volumetric cardiac ultrasound imaging has steadily evolved over the last 20 years from an electrocardiography (ECC) gated imaging technique to a true real-time imaging modality. Although the clinical use of echocardiography is still to a large extent based on conventional 2D ultrasound imaging it can be anticipated that the further developments in image quality, data visualization and interaction and image quantification of three-dimensional cardiac ultrasound will gradually make volumetric ultrasound the modality of choice. In this chapter, an overview is given of the technological developments that allow for volumetric imaging of the beating heart by ultrasound.

  1. Cardiac Involvement in Peripheral Neuropathies.

    PubMed

    Burakgazi, Ahmet Z; AlMahameed, Soufian

    2016-03-01

    Cardiac autonomic neuropathy (CAN) is the least recognized and understood complication of peripheral neuropathy. However, because of its potential adverse effects including sudden death, CAN is one of the most important forms of autonomic neuropathies. CAN presents with different clinical manifestations including postural hypotension, exercise intolerance, fluctuation of blood pressure and heart rate, arrhythmia, and increased risk of myocardial infarction. In this article, the prevalence, clinical presentations, and management of cardiac involvement in certain peripheral neuropathies, including diabetic neuropathy, Guillain-Barré syndrome, chronic inflammatory polyneuropathy, human immunodeficiency virus-associated neuropathy, hereditary neuropathies, and amyloid neuropathy are examined in detail.

  2. [Cardiac rehabilitation after myocardial infarction].

    PubMed

    Ghannem, M; Ghannem, L; Ghannem, L

    2015-12-01

    Although the proofs of the benefits of cardiac rehabilitation accumulate, many patients are not sent to rehabilitation units, especially younger and very elderly patients. As the length of stay in acute care units decreases, rehabilitation offers more time to fully assess the patients' conditions and needs. Meta-analyses of randomised trials suggest that mortality can be improved by as much as 20-30%. In addition, rehabilitation helps managing risk factors, including hyperlipidemia, diabetes, smoking and sedentary behaviours. Physical training also helps improving exercise capacity. Because of all of these effects, cardiac rehabilitation for post-myocardial infarction patients has been given a class IA recommendation in current guidelines.

  3. Systemic therapy for cardiac sarcomas.

    PubMed

    Ravi, Vinod; Benjamin, Robert S

    2010-01-01

    Cardiac sarcomas create 2 risks: local problems and metastatic disease. Most frequently, the histologies are angiosarcoma and high-grade pleomorphic unclassified sarcoma (formerly called MFH or malignant fibrous histiocytoma). There is also a clinical-pathological entity without distinctive histological features of tumors that originate in the pulmonary artery and are referred to as pulmonary artery sarcomas or intimal sarcomas of the pulmonary artery. Conventional wisdom indicates that soft-tissue sarcomas are poorly responsive to chemotherapy. Luckily, that is not the case. Attempts to concentrate on the local problem only with therapies up to and including cardiac transplantation have been unsuccessful due to the high rate of fatal metastatic disease.

  4. Cardiac Metastasis from Invasive Thymoma Via the Superior Vena Cava: Cardiac MRI Findings

    SciTech Connect

    Dursun, Memduh Sarvar, Sadik; Cekrezi, Bledi; Kaba, Erkan; Bakir, Baris; Toker, Alper

    2008-07-15

    Cardiac tumors are rare, and metastatic deposits are more common than primary cardiac tumors. We present cardiac magnetic resonance imaging (MRI) findings of a 50-year-old woman with invasive thymoma. Cardiac MRI revealed a heterogeneous, lobulated anterior mediastinal mass invading the superior vena cava and extending to the right atrium. In cine images there was no invasion to the right atrial wall.

  5. Health Literacy Predicts Cardiac Knowledge Gains in Cardiac Rehabilitation Participants

    ERIC Educational Resources Information Center

    Mattson, Colleen C.; Rawson, Katherine; Hughes, Joel W.; Waechter, Donna; Rosneck, James

    2015-01-01

    Objective: Health literacy is increasingly recognised as a potentially important patient characteristic related to patient education efforts. We evaluated whether health literacy would predict gains in knowledge after completion of patient education in cardiac rehabilitation. Method: This was a re-post observational analysis study design based on…

  6. Bifid cardiac apex in a 25-year-old male with sudden cardiac death.

    PubMed

    Wu, Annie; Kay, Deborah; Fishbein, Michael C

    2014-01-01

    Although a bifid cardiac apex is common in certain marine animals, it is an uncommon finding in humans. When present, bifid cardiac apex is usually associated with other congenital heart anomalies. We present a case of bifid cardiac apex that was an incidental finding in a 25-year-old male with sudden cardiac death from combined drug toxicity. On gross examination, there was a bifid cardiac apex with a 2-cm long cleft. There were no other significant gross or microscopic abnormalities. This case represents the very rare occurrence of a bifid cardiac apex as an isolated cardiac anomaly.

  7. Variational Reconstruction of Left Cardiac Structure from CMR Images

    PubMed Central

    Wan, Min; Huang, Wei; Zhang, Jun-Mei; Zhao, Xiaodan; Tan, Ru San; Wan, Xiaofeng; Zhong, Liang

    2015-01-01

    Cardiovascular Disease (CVD), accounting for 17% of overall deaths in the USA, is the leading cause of death over the world. Advances in medical imaging techniques make the quantitative assessment of both the anatomy and function of heart possible. The cardiac modeling is an invariable prerequisite for quantitative analysis. In this study, a novel method is proposed to reconstruct the left cardiac structure from multi-planed cardiac magnetic resonance (CMR) images and contours. Routine CMR examination was performed to acquire both long axis and short axis images. Trained technologists delineated the endocardial contours. Multiple sets of two dimensional contours were projected into the three dimensional patient-based coordinate system and registered to each other. The union of the registered point sets was applied a variational surface reconstruction algorithm based on Delaunay triangulation and graph-cuts. The resulting triangulated surfaces were further post-processed. Quantitative evaluation on our method was performed via computing the overlapping ratio between the reconstructed model and the manually delineated long axis contours, which validates our method. We envisage that this method could be used by radiographers and cardiologists to diagnose and assess cardiac function in patients with diverse heart diseases. PMID:26689551

  8. Tissue and Animal Models of Sudden Cardiac Death

    PubMed Central

    Sallam, Karim; Li, Yingxin; Sager, Philip T.; Houser, Steven R.; Wu, Joseph C.

    2015-01-01

    Sudden Cardiac Death (SCD) is a common cause of death in patients with structural heart disease, genetic mutations or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with SCD. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell derived Cardiomyocytes (iPSC-CMs) resemble, but are not identical, to adult human cardiomyocytes, and provide a new platform for studying arrhythmic disorders leading to SCD. A variety of platforms exist to phenotype cellular models including conventional and automated patch clamp, multi-electrode array, and computational modeling. iPSC-CMs have been used to study Long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy and other hereditary cardiac disorders. Although iPSC-CMs are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of SCD. PMID:26044252

  9. Cardiac calcified amorphous tumors: CT and MRI findings

    PubMed Central

    Yılmaz, Ravza; Demir, Ali Aslan; Önür, İmran; Yılbazbayhan, Dilek; Dursun, Memduh

    2016-01-01

    PURPOSE We aimed to evaluate computed tomography (CT) and magnetic resonance imaging (MRI) findings of cardiac calcified amorphous tumors (CATs). METHODS CT and MRI findings of cardiac CATs in 12 patients were included. We retrospectively examined patient demographics, location, size, shape configuration, imaging features, calcification distribution of tumors, and accompanying medical problems. RESULTS There was a female predominance (75%), with a mean age at presentation of 65 years. Patients were mostly asymptomatic on presentation (58.3%). The left ventricle of the heart was mostly involved (91%). CT findings of CATs were classified as partial calcification with a hypodense mass in four patients or a diffuse calcified form in eight. Calcification was predominant with large foci appearance as in partially calcified masses. On T1- and T2-weighted magnetic resonance images, CATs appeared hypointense and showed no contrast enhancement. CONCLUSION The shape and configuration of cardiac CATs are variable with a narrow spectrum of CT and MRI findings, but large foci in a partially calcified mass or diffuse calcification of a mass on CT is very important in the diagnosis of cardiac CATs. Masses show a low signal intensity on T1- and T2-weighted images with no contrast enhancement on MRI. PMID:27705878

  10. Cardiac Sarcoidosis Diagnosed by Incidental Lymph Node Biopsy.

    PubMed

    Matsuda, Jun; Fujiu, Katsuhito; Roh, Solji; Tajima, Miyu; Maki, Hisataka; Kojima, Toshiya; Ushiku, Tetsuo; Nawata, Kan; Takeda, Norihiko; Watanabe, Masafumi; Akazawa, Hiroshi; Komuro, Issei

    2017-02-07

    Cardiac involvement in systemic sarcoidosis sometimes provokes life-threatening ventricular tachyarrhythmia. Steroid administration is one of the fundamental anti-arrhythmia therapies. For an indication of steroid therapy, a definitive diagnosis of sarcoidosis is required.(1)) However, cases that are clearly suspected of cardiac sarcoidosis based on their clinical courses sometimes do not meet the current diagnostic criteria and result in the loss of an appropriate opportunity to perform steroid therapy.Here we report a case that was diagnosed as sarcoidosis by incidental biopsy of an inguinal lymph node during cardiac resuscitation for cardiac tamponade.(2)) While the inguinal lymph node was not swollen on computed tomography, a specimen obtained from an incidental biopsy during the exposure of a femoral vessel for the establishment of extracorporeal cardio-pulmonary resuscitation showed a non-caseating granuloma.This findings suggest a non-swelling lymph node biopsy might be an alternative strategy for the diagnosis for sarcoidosis if other standard strategies do not result in a diagnosis of sarcoidosis.

  11. Mathematics and the Heart: Understanding Cardiac Output

    ERIC Educational Resources Information Center

    Champanerkar, Jyoti

    2013-01-01

    This paper illustrates a biological application of the concepts of relative change and area under a curve, from mathematics. We study two biological measures "relative change in cardiac output" and "cardiac output", which are predictors of heart blockages and other related ailments. Cardiac output refers to the quantity of…

  12. Discovery and progress of direct cardiac reprogramming.

    PubMed

    Kojima, Hidenori; Ieda, Masaki

    2017-02-14

    Cardiac disease remains a major cause of death worldwide. Direct cardiac reprogramming has emerged as a promising approach for cardiac regenerative therapy. After the discovery of MyoD, a master regulator for skeletal muscle, other single cardiac reprogramming factors (master regulators) have been sought. Discovery of cardiac reprogramming factors was inspired by the finding that multiple, but not single, transcription factors were needed to generate induced pluripotent stem cells (iPSCs) from fibroblasts. We first reported a combination of cardiac-specific transcription factors, Gata4, Mef2c, and Tbx5 (GMT), that could convert mouse fibroblasts into cardiomyocyte-like cells, which were designated as induced cardiomyocyte-like cells (iCMs). Following our first report of cardiac reprogramming, many researchers, including ourselves, demonstrated an improvement in cardiac reprogramming efficiency, in vivo direct cardiac reprogramming for heart regeneration, and cardiac reprogramming in human cells. However, cardiac reprogramming in human cells and adult fibroblasts remains inefficient, and further efforts are needed. We believe that future research elucidating epigenetic barriers and molecular mechanisms of direct cardiac reprogramming will improve the reprogramming efficiency, and that this new technology has great potential for clinical applications.

  13. Cardiac anatomy and physiology: a review.

    PubMed

    Gavaghan, M

    1998-04-01

    This article reviews the normal anatomy and physiology of the heart. Understanding the normal anatomic and physiologic relationships described in this article will help perioperative nurses care for patients who are undergoing cardiac procedures. Such knowledge also assists nurses in educating patients about cardiac procedures and about activities that can prevent, reverse, or improve cardiac illness.

  14. Bifurcation theory and cardiac arrhythmias

    PubMed Central

    Karagueuzian, Hrayr S; Stepanyan, Hayk; Mandel, William J

    2013-01-01

    In this paper we review two types of dynamic behaviors defined by the bifurcation theory that are found to be particularly useful in describing two forms of cardiac electrical instabilities that are of considerable importance in cardiac arrhythmogenesis. The first is action potential duration (APD) alternans with an underlying dynamics consistent with the period doubling bifurcation theory. This form of electrical instability could lead to spatially discordant APD alternans leading to wavebreak and reentrant form of tachyarrhythmias. Factors that modulate the APD alternans are discussed. The second form of bifurcation of importance to cardiac arrhythmogenesis is the Hopf-homoclinic bifurcation that adequately describes the dynamics of the onset of early afterdepolarization (EAD)-mediated triggered activity (Hopf) that may cause ventricular tachycardia and ventricular fibrillation (VT/VF respectively). The self-termination of the triggered activity is compatible with the homoclinic bifurcation. Ionic and intracellular calcium dynamics underlying these dynamics are discussed using available experimental and simulation data. The dynamic analysis provides novel insights into the mechanisms of VT/VF, a major cause of sudden cardiac death in the US. PMID:23459417

  15. Device Assists Cardiac Chest Compression

    NASA Technical Reports Server (NTRS)

    Eichstadt, Frank T.

    1995-01-01

    Portable device facilitates effective and prolonged cardiac resuscitation by chest compression. Developed originally for use in absence of gravitation, also useful in terrestrial environments and situations (confined spaces, water rescue, medical transport) not conducive to standard manual cardiopulmonary resuscitation (CPR) techniques.

  16. Cardiac arrest during dipyridamole imaging

    SciTech Connect

    Blumenthal, M.S.; McCauley, C.S.

    1988-05-01

    A case of cardiac arrest and subsequent acute myocardial infarction occurring during thallium-201 imaging with oral dipyridamole augmentation is presented. Previous reports emphasizing the safety of this procedure are briefly reviewed and a recommendation for close hemodynamic and arrhythmia monitoring during the study is made. Large doses of oral dipyridamole may be contraindicated in patients with unstable angina.

  17. Guide to prosthetic cardiac valves

    SciTech Connect

    Morse, D.; Steiner, R.M.; Fernandez, J.

    1985-01-01

    This book contains 10 chapters. Some of the chapter titles are: The development of artificial heart valves: Introduction and historical perspective; The radiology of prosthetic heart valves; The evaluation of patients for prosthetic valve implantation; Pathology of cardiac valve replacement; and Bioengineering of mechanical and biological heart valve substitutes.

  18. Cardiac sarcoidosis: diagnosis and management.

    PubMed

    Dubrey, S W; Sharma, R; Underwood, R; Mittal, T

    2015-07-01

    Cardiac sarcoidosis is one of the most serious and unpredictable aspects of this disease state. Heart involvement frequently presents with arrhythmias or conduction disease, although myocardial infiltration resulting in congestive heart failure may also occur. The prognosis in cardiac sarcoidosis is highly variable, which relates to the heterogeneous nature of heart involvement and marked differences between racial groups. Electrocardiography and echocardiography often provide the first clue to the diagnosis, but advanced imaging studies using positron emission tomography and MRI, in combination with nuclear isotope perfusion scanning are now essential to the diagnosis and management of this condition. The identification of clinically occult cardiac sarcoidosis and the management of isolated and/or asymptomatic heart involvement remain both challenging and contentious. Corticosteroids remain the first treatment choice with the later substitution of immunosuppressive and steroid-sparing therapies. Heart transplantation is an unusual outcome, but when performed, the results are comparable or better than heart transplantation for other disease states. We review the epidemiology, developments in diagnostic techniques and the management of cardiac sarcoidosis.

  19. Cardiac arrhythmias in paediatric practice.

    PubMed

    Chan, K Y; Loke, K Y; Yip, W C; Tay, J S

    1989-01-01

    Clinical data of patients with cardiac arrhythmias managed between May 1986 and March 1988 were reviewed to determine their mode of presentation and clinical course. Of the 5,768 admissions, 62 (1.07%) patients had arrhythmias. During the same period, 21 patients were managed as outpatients with 13 being new referrals. Thirty-eight patients had undergone corrective cardiac procedures, 8 others had congenital heart lesions, 3 were associated with acquired cardiac pathology and the remaining had isolated arrhythmias. The cardiac arrhythmias were: right bundle branch block 36, premature atrial and ventricular contractions 15, supraventricular tachycardia (SVT) 15, atrioventricular (AV) block 7, sinus bradycardia 3, atrial fibrillation 2, ventricular tachycardia and fibrillation 2, Wolff-Parkinson-White syndrome without SVT 2, bradytachyarrhythmia 1. There were 3 patients with foetal SVT, one persisting till day 1. High grade AV block occurred in 2 patients post-surgically and needed pacing. Only 2 others were symptomatic. Other than the 38 patients who underwent corrective procedures (2 had balloon valvuloplasty for pulmonary stenosis), 8 others had structural heart disease. There was 1 sudden death and 5 died from their primary heart disease.

  20. Automatic referral to cardiac rehabilitation.

    PubMed

    Fischer, Jane P

    2008-01-01

    The pervasive negative impact of cardiovascular disease in the United States is well documented. Although advances have been made, the campaign to reduce the occurrence, progression, and mortality continues. Determining evidence-based data is only half the battle. Implementing new and updated clinical guidelines into daily practice is a challenging task. Cardiac rehabilitation is an example of a proven intervention whose benefit is hindered through erratic implementation. The American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR), the American College of Cardiology (ACC), and the American Heart Association (AHA) have responded to this problem by publishing the AACVPR/ACC/AHA 2007 Performance Measures on Cardiac Rehabilitation for Referral to and Delivery of Cardiac Rehabilitation/Secondary Prevention Services. This new national guideline recommends automatic referral to cardiac rehabilitation for every eligible patient (performance measure A-1). This article offers guidance for the initiation of an automatic referral system, including individualizing your protocol with regard to electronic or paper-based order entry structures.

  1. Molecular Modeling of Cardiac Troponin

    NASA Astrophysics Data System (ADS)

    Manning, Edward P.

    The cardiac thin filament regulates interactions of actin and myosin, the force-generating elements of muscular contraction. Over the past several decades many details have been discovered regarding the structure and function of the cardiac thin filament and its components, including cardiac troponin (cTn). My hypothesis is that signal propagation occurs between distant ends of the cardiac troponin complex through calcium-dependent alterations in the dynamics of cTn and tropomyosin (Tm). I propose a model of the thin filament that encompasses known structures of cTn, Tm and actin to gain insight into cardiac troponin's allosteric regulation of thin filament dynamics. By performing molecular dynamics simulations of cTn in conjunction with overlapping Tm in two conditions, with and without calcium bound to site II of cardiac troponin C (cTnC), I found a combination of calcium-dependent changes in secondary structure and dynamics throughout the cTn-Tm complex. I then applied this model to investigate familial hypertrophic cardiomyopathy (FHC), a disease of the sarcomere that is one of the most commonly occurring genetic causes of heart disease. Approximately 15% of known FHC-related mutations are found in cardiac troponin T (cTnT), most of which are in or flank the alpha-helical N-tail domain TNT1. TNT1 directly interacts with overlapping Tm coiled coils. Using this model I identified effects of TNT1 mutations that propagate to the cTn core where site II of cTnC, the regulatory site of calcium binding in the thin filament, is located. Specifically, I found that mutations in TNT1 alter the flexibility of TNT1 and that the flexibility of TNT1 is inversely proportional to the cooperativity of calcium activation of the thin filament. Further, I identified a pathway of propagation of structural and dynamic changes linking TNT1 to site II of cTnC. Mutation-induced changes at site II cTnC alter calcium coordination which corresponds to biophysical measurements of calcium

  2. Cardiac arrest: resuscitation and reperfusion.

    PubMed

    Patil, Kaustubha D; Halperin, Henry R; Becker, Lance B

    2015-06-05

    The modern treatment of cardiac arrest is an increasingly complex medical procedure with a rapidly changing array of therapeutic approaches designed to restore life to victims of sudden death. The 2 primary goals of providing artificial circulation and defibrillation to halt ventricular fibrillation remain of paramount importance for saving lives. They have undergone significant improvements in technology and dissemination into the community subsequent to their establishment 60 years ago. The evolution of artificial circulation includes efforts to optimize manual cardiopulmonary resuscitation, external mechanical cardiopulmonary resuscitation devices designed to augment circulation, and may soon advance further into the rapid deployment of specially designed internal emergency cardiopulmonary bypass devices. The development of defibrillation technologies has progressed from bulky internal defibrillators paddles applied directly to the heart, to manually controlled external defibrillators, to automatic external defibrillators that can now be obtained over-the-counter for widespread use in the community or home. But the modern treatment of cardiac arrest now involves more than merely providing circulation and defibrillation. As suggested by a 3-phase model of treatment, newer approaches targeting patients who have had a more prolonged cardiac arrest include treatment of the metabolic phase of cardiac arrest with therapeutic hypothermia, agents to treat or prevent reperfusion injury, new strategies specifically focused on pulseless electric activity, which is the presenting rhythm in at least one third of cardiac arrests, and aggressive post resuscitation care. There are discoveries at the cellular and molecular level about ischemia and reperfusion pathobiology that may be translated into future new therapies. On the near horizon is the combination of advanced cardiopulmonary bypass plus a cocktail of multiple agents targeted at restoration of normal metabolism and

  3. Cardiac energetics: sense and nonsense.

    PubMed

    Gibbs, Colin L

    2003-08-01

    1. The background to current ideas in cardiac energetics is outlined and, in the genomic era, the need is stressed for detailed knowledge of mouse heart mechanics and energetics. 2. The mouse heart is clearly different to the rat in terms of its excitation-contraction (EC) coupling and the common assumption that heart rate difference between mice and humans will account for the eightfold difference in myocardial oxygen consumption is wrong, because the energy per beat of the mouse heart is approximately one-third that of the human heart. 3. In vivo evidence suggests that there may well be an eightfold species difference in the non-beating metabolism of mice and human hearts. It is speculated that the magnitude of basal metabolism in the heart is regulatable and that, in the absence of perfusion, it falls to approximately one-quarter of its in vivo rate and that in clinical conditions, such as hibernation, it probably decreases; its magnitude may be controlled by the endothelium. 4. The active energy balance sheet is briefly discussed and it is suggested that the activation heat accounts for 20-25% of the active energy per beat and cross-bridge turnover accounts for the balance. It is argued that force, not shortening, is the major determinant of cardiac energy usage. 5. The outcome of recent cardiac modelling with variants of the Huxley and Hill/Eisenberg models is described. It has been necessary to invoke 'loose coupling' to replicate the low cardiac energy flux measured at low afterloads (medium to high velocities of shortening). 6. Lastly, some of the unexplained or 'nonsense' energetic data are outlined and eight unsolved problems in cardiac energetics are discussed.

  4. Advances in cardiac processing software.

    PubMed

    Gordon DePuey, Ernest

    2014-07-01

    New software methods that incorporate iterative reconstruction, resolution recovery, and noise compensation now provide the ability to maintain or improve myocardial perfusion SPECT image quality with conventional sodium iodide cameras. Despite lower image counting statistics associated with significantly decreased injected radiopharmaceutical doses or shortened acquisition times or both, image quality is preserved or even improved compared with conventional processing methods. The ability to prescribe a desired myocardial count density by preselecting a SPECT acquisition time now avoids additional patient radiation exposure associated with "weight-based" dosing. More recent advancements, including temporal correlation among the gated perfusion frames and higher resolution SPECT acquisitions, hold promise to further improve image quality and diagnostic accuracy. Phase analysis of gated perfusion SPECT provides the ability to assess cardiac dyssynchrony and to select those patients who will most benefit from resynchronization therapy. In combination with the higher counting statistics afforded by the new solid-state dedicated cardiac cameras, these software advancements allow for even further decreased patient radiation doses or acquisition times or both. List-mode software allows for refinement of myocardial perfusion SPECT by interrogating particular data from selected cardiac cycles. Rejection of frames degraded by arrhythmic cardiac cycles or excessive extracardiac uptake can be excluded for reconstruction. Respiratory gating, which diminishes cardiac motion and potentially decreases diaphragmatic attenuation, has been demonstrated to improve diagnostic specificity. With high-count first-pass list-mode acquisitions at rest and during pharmacologic vasodilatation, it may be possible to measure global and regional myocardial perfusion reserve to more accurately diagnose coronary artery disease and avoid false-negative studies owing to balanced ischemia.

  5. Can cardiac surgery cause hypopituitarism?

    PubMed

    Francis, Flverly; Burger, Ines; Poll, Eva Maria; Reineke, Andrea; Strasburger, Christian J; Dohmen, Guido; Gilsbach, Joachim M; Kreitschmann-Andermahr, Ilonka

    2012-03-01

    Apoplexy of pituitary adenomas with subsequent hypopituitarism is a rare but well recognized complication following cardiac surgery. The nature of cardiac on-pump surgery provides a risk of damage to the pituitary because the vascular supply of the pituitary is not included in the cerebral autoregulation. Thus, pituitary tissue may exhibit an increased susceptibility to hypoperfusion, ischemia or intraoperative embolism. After on-pump procedures, patients often present with physical and psychosocial impairments which resemble symptoms of hypopituitarism. Therefore, we analyzed whether on-pump cardiac surgery may cause pituitary dysfunction also in the absence of pre-existing pituitary disease. Twenty-five patients were examined 3-12 months after on-pump cardiac surgery. Basal hormone levels for all four anterior pituitary hormone axes were measured and a short synacthen test and a growth hormone releasing hormone plus arginine (GHRH-ARG)-test were performed. Quality of life (QoL), depression, subjective distress for a specific life event, sleep quality and fatigue were assessed by means of self-rating questionnaires. Hormonal alterations were only slight and no signs of anterior hypopituitarism were found except for an insufficient growth hormone rise in two overweight patients in the GHRH-ARG-test. Psychosocial impairment was pronounced, including symptoms of moderate to severe depression in 9, reduced mental QoL in 8, dysfunctional coping in 6 and pronounced sleep disturbances in 16 patients. Hormone levels did not correlate with psychosocial impairment. On-pump cardiac surgery did not cause relevant hypopituitarism in our sample of patients and does not serve to explain the psychosocial symptoms of these patients.

  6. Using cardiac biomarkers in veterinary practice.

    PubMed

    Oyama, Mark A

    2013-11-01

    Blood-based assays for various cardiac biomarkers can assist in the diagnosis of heart disease in dogs and cats. The two most common markers are cardiac troponin-I and N-terminal pro-B-type natriuretic peptide. Biomarker assays can assist in differentiating cardiac from noncardiac causes of respiratory signs and detection of preclinical cardiomyopathy. Increasingly, studies indicate that cardiac biomarker testing can help assess the risk of morbidity and mortality in animals with heart disease. Usage of cardiac biomarker testing in clinical practice relies on proper patient selection, correct interpretation of test results, and incorporation of biomarker testing into existing diagnostic methods.

  7. Using Cardiac Biomarkers in Veterinary Practice.

    PubMed

    Oyama, Mark A

    2015-09-01

    Blood-based assays for various cardiac biomarkers can assist in the diagnosis of heart disease in dogs and cats. The two most common markers are cardiac troponin-I and N-terminal pro-B-type natriuretic peptide. Biomarker assays can assist in differentiating cardiac from noncardiac causes of respiratory signs and detection of preclinical cardiomyopathy. Increasingly, studies indicate that cardiac biomarker testing can help assess the risk of morbidity and mortality in animals with heart disease. Usage of cardiac biomarker testing in clinical practice relies on proper patient selection, correct interpretation of test results, and incorporation of biomarker testing into existing diagnostic methods.

  8. Measurement of cardiac output in adult and newborn animals by ascorbic acid dilution.

    PubMed

    Smallwood, J K; Haselby, K A; Paradise, R R

    1984-05-01

    We have developed an ascorbic acid-dilution method for measuring cardiac output which requires minimal blood withdrawal. Ascorbate is injected into a central venous catheter. The indicator-dilution curve is obtained by drawing blood from an arterial catheter through an amperometric cell at 0.96 ml/min for 35 s. The current is measured by a picoammeter . A calibration curve is obtained in 15 s prior to each indicator-dilution curve. An on-line digital computer measures the curve areas and calculates the cardiac output. Cardiac outputs of heparinized dogs anesthetized with pentobarbital and halothane measured by this method (AA) compared closely to cardiac outputs measured by the dye-dilution method (CG) (AA = 0.96 CG + 20 ml/min, r = 0.98). Both the cardiac output and the arterial blood pressure remained stable during replicate measurements of the cardiac output of 1-day-old piglets. This system allows cardiac output determinations of neonatal subjects without excessive blood removal and, with further development, should be practical in human neonates.

  9. Fast automatic delineation of cardiac volume of interest in MSCT images

    NASA Astrophysics Data System (ADS)

    Lorenz, Cristian; Lessick, Jonathan; Lavi, Guy; Bulow, Thomas; Renisch, Steffen

    2004-05-01

    Computed Tomography Angiography (CTA) is an emerging modality for assessing cardiac anatomy. The delineation of the cardiac volume of interest (VOI) is a pre-processing step for subsequent visualization or image processing. It serves the suppression of anatomic structures being not in the primary focus of the cardiac application, such as sternum, ribs, spinal column, descending aorta and pulmonary vasculature. These structures obliterate standard visualizations such as direct volume renderings or maximum intensity projections. In addition, outcome and performance of post-processing steps such as ventricle suppression, coronary artery segmentation or the detection of short and long axes of the heart can be improved. The structures being part of the cardiac VOI (coronary arteries and veins, myocardium, ventricles and atria) differ tremendously in appearance. In addition, there is no clear image feature associated with the contour (or better cut-surface) distinguishing between cardiac VOI and surrounding tissue making the automatic delineation of the cardiac VOI a difficult task. The presented approach locates in a first step chest wall and descending aorta in all image slices giving a rough estimate of the location of the heart. In a second step, a Fourier based active contour approach delineates slice-wise the border of the cardiac VOI. The algorithm has been evaluated on 41 multi-slice CT data-sets including cases with coronary stents and venous and arterial bypasses. The typical processing time amounts to 5-10s on a 1GHz P3 PC.

  10. Diagnostic accuracy of sub-mSv prospective ECG-triggering cardiac CT in young infant with complex congenital heart disease.

    PubMed

    Gao, Wei; Zhong, Yu Min; Sun, Ai Min; Wang, Qian; Ouyang, Rong Zhen; Hu, Li Wei; Qiu, Han Sheng; Wang, Shi Yu; Li, Jian Ying

    2016-06-01

    To explore the clinical value and evaluate the diagnostic accuracy of sub-mSv low-dose prospective ECG-triggering cardiac CT (CCT) in young infants with complex congenital heart disease (CHD). A total of 102 consecutive infant patients (53 boys and 49 girls with mean age of 2.9 ± 2.4 m and weight less than 5 kg) with complex CHD were prospectively enrolled. Scans were performed on a 64-slice high definition CT scanner with low dose prospective ECG-triggering mode and reconstructed with 80 % adaptive statistical iterative reconstruction algorithm. All studies were performed during free breathing with sedation. The subjective image quality was evaluated by 5-point grading scale and interobserver variability was calculated. The objective image noise (standard deviation, SD) and contrast to noise ratio (CNR) was calculated. The effective radiation dose from the prospective ECG-triggering mode was recorded and compared with the virtual conventional retrospective ECG-gating mode. The detection rate for the origin of coronary artery was calculated. All patients also underwent echocardiography before CCT examination. 81 patients had surgery and their preoperative CCT and echocardiography findings were compared with the surgical results and sensitivity, specificity, positive and negative predictive values and accuracy were calculated for separate cardiovascular anomalies. Heart rates were 70-161 beats per minute (bpm) with mean value of 129.19 ± 14.52 bpm. The effective dose of 0.53 ± 0.15 mSv in the prospective ECG-triggering cardiac CT was lower than the calculated value in a conventional retrospective ECG-gating mode (2.00 ± 0.35 mSv) (p < 0.001). The mean CNR and SD were 28.19 ± 13.00 and 15.75 ± 3.61HU, respectively. The image quality scores were 4.31 ± 0.36 and 4.29 ± 0.41 from reviewer 1 and 2 respectively with an excellent agreement between them (Kappa = 0.85). The detection rate for the origins of the left and right coronary

  11. Whole body magnetic resonance angiography and computed tomography angiography in the vascular mapping of head and neck: an intraindividual comparison

    PubMed Central

    2014-01-01

    Introduction The aim of the study was to compare the detectability of neck vessels with contrast enhanced magnetic resonance angiography (MRA) in the setting of a whole-body MRA and multislice computed tomography angiography (CTA) for preoperative vascular mapping of head and neck. Methods In 20 patients MRA was performed prior to microvascular reconstruction of the mandible with osteomyocutaneous flaps. CTA of the neck served as the method of reference. 1.5 T contrast enhanced magnetic resonance angiograms were acquired to visualize the vascular structures of the neck in the setting of a whole-body MRA examination. 64-slice spiral computed tomography was performed with a dual-phase protocol, using the arterial phase images for 3D CTA reconstruction. Maximum intensity projection was employed to visualize MRA and CTA data. To retrieve differences in the detectability of vessel branches between MRA and CTA, a McNemar test was performed. Results All angiograms were of diagnostic quality. There were no statistically significant differences between MRA and CTA for the detection of branches of the external carotid artery that are relevant host vessels for microsurgery (p = 0.118). CTA was superior to MRA if all the external carotid artery branches were included (p < 0.001). Conclusions MRA is a reliable alternative to CTA in vascular mapping of the cervical vasculature for planning of microvascular reconstruction of the mandible. In the setting of whole-body MRA it could serve as a radiation free one-stop-shop tool for preoperative assessment of the arterial system, potentially covering both, the donor and host site in one single examination. PMID:24884580

  12. Changes in entrance surface dose in relation to the location of shielding material in chest computed tomography

    NASA Astrophysics Data System (ADS)

    Kang, Y. M.; Cho, J. H.; Kim, S. C.

    2015-07-01

    This study examined the effects of entrance surface dose (ESD) on the abdomen and pelvis of the patient when undergoing chest computed tomography (CT) procedure, and evaluated the effects of ESD reduction depending on the location of radiation shield. For CT scanner, the 64-slice multi-detector computed tomography was used. The alderson radiation therapy phantom and optically stimulated luminescence dosimeter (OSLD), which enabled measurement from low to high dose, were also used. For measurement of radiation dose, the slice number from 9 to 21 of the phantom was set as the test range, which included apex up to both costophrenic angles. A total of 10 OSLD nanoDots were attached for measurement of the front and rear ESD. Cyclic tests were performed using the low-dose chest CT and high-resolution CT (HRCT) protocol on the following set-ups: without shielding; shielding only on the front side; shielding only on the rear side; and shielding for both front and rear sides. According to the test results, ESD for both front and rear sides was higher in HRCT than low-dose CT when radiation shielding was not used. It was also determined that, compared to the set-up that did not use the radiation shield, locating the radiation shield on the front side was effective in reducing front ESD, while locating the radiation shield on the rear side reduced rear ESD level. Shielding both the front and rear sides resulted in ESD reduction. In conclusion, it was confirmed that shielding the front and rear sides was the most effective method to reduce the ESD effect caused by scatter ray during radiography.

  13. Cardiac catheterization laboratory imaging quality assurance program.

    PubMed

    Wondrow, M A; Laskey, W K; Hildner, F J; Cusma, J; Holmes, D R

    2001-01-01

    With the recent approval of the National Electrical Manufacturers Association (NEMA) standard for "Characteristics of and Test Procedures for a Phantom to Benchmark Cardiac Fluoroscopic and Photographic Performance," comprehensive cardiac image assurance control programs are now possible. This standard was developed by a joint NEMA/Society for Cardiac Angiography and Interventions (SCA&I) working group of imaging manufacturers and cardiology society professionals over the past 4 years. This article details a cardiac catheterization laboratory image quality assurance and control program that includes the new standard along with current regulatory requirements for cardiac imaging. Because of the recent proliferation of digital imaging equipment, quality assurance for cardiac imaging fluoroscopy and digital imaging are critical. Included are the previous works recommended by the American College of Cardiology (ACC) and American Heart Association (AHA), Society for Cardiac Angiographers and Interventions (SCA&I), and authors of previous image quality subjects.

  14. High-order finite element methods for cardiac monodomain simulations

    PubMed Central

    Vincent, Kevin P.; Gonzales, Matthew J.; Gillette, Andrew K.; Villongco, Christopher T.; Pezzuto, Simone; Omens, Jeffrey H.; Holst, Michael J.; McCulloch, Andrew D.

    2015-01-01

    Computational modeling of tissue-scale cardiac electrophysiology requires numerically converged solutions to avoid spurious artifacts. The steep gradients inherent to cardiac action potential propagation necessitate fine spatial scales and therefore a substantial computational burden. The use of high-order interpolation methods has previously been proposed for these simulations due to their theoretical convergence advantage. In this study, we compare the convergence behavior of linear Lagrange, cubic Hermite, and the newly proposed cubic Hermite-style serendipity interpolation methods for finite element simulations of the cardiac monodomain equation. The high-order methods reach converged solutions with fewer degrees of freedom and longer element edge lengths than traditional linear elements. Additionally, we propose a dimensionless number, the cell Thiele modulus, as a more useful metric for determining solution convergence than element size alone. Finally, we use the cell Thiele modulus to examine convergence criteria for obtaining clinically useful activation patterns for applications such as patient-specific modeling where the total activation time is known a priori. PMID:26300783

  15. High-order finite element methods for cardiac monodomain simulations.

    PubMed

    Vincent, Kevin P; Gonzales, Matthew J; Gillette, Andrew K; Villongco, Christopher T; Pezzuto, Simone; Omens, Jeffrey H; Holst, Michael J; McCulloch, Andrew D

    2015-01-01

    Computational modeling of tissue-scale cardiac electrophysiology requires numerically converged solutions to avoid spurious artifacts. The steep gradients inherent to cardiac action potential propagation necessitate fine spatial scales and therefore a substantial computational burden. The use of high-order interpolation methods has previously been proposed for these simulations due to their theoretical convergence advantage. In this study, we compare the convergence behavior of linear Lagrange, cubic Hermite, and the newly proposed cubic Hermite-style serendipity interpolation methods for finite element simulations of the cardiac monodomain equation. The high-order methods reach converged solutions with fewer degrees of freedom and longer element edge lengths than traditional linear elements. Additionally, we propose a dimensionless number, the cell Thiele modulus, as a more useful metric for determining solution convergence than element size alone. Finally, we use the cell Thiele modulus to examine convergence criteria for obtaining clinically useful activation patterns for applications such as patient-specific modeling where the total activation time is known a priori.

  16. euHeart: personalized and integrated cardiac care using patient-specific cardiovascular modelling

    PubMed Central

    Smith, Nic; de Vecchi, Adelaide; McCormick, Matthew; Nordsletten, David; Camara, Oscar; Frangi, Alejandro F.; Delingette, Hervé; Sermesant, Maxime; Relan, Jatin; Ayache, Nicholas; Krueger, Martin W.; Schulze, Walther H. W.; Hose, Rod; Valverde, Israel; Beerbaum, Philipp; Staicu, Cristina; Siebes, Maria; Spaan, Jos; Hunter, Peter; Weese, Juergen; Lehmann, Helko; Chapelle, Dominique; Rezavi, Reza

    2011-01-01

    The loss of cardiac pump function accounts for a significant increase in both mortality and morbidity in Western society, where there is currently a one in four lifetime risk, and costs associated with acute and long-term hospital treatments are accelerating. The significance of cardiac disease has motivated the application of state-of-the-art clinical imaging techniques and functional signal analysis to aid diagnosis and clinical planning. Measurements of cardiac function currently provide high-resolution datasets for characterizing cardiac patients. However, the clinical practice of using population-based metrics derived from separate image or signal-based datasets often indicates contradictory treatments plans owing to inter-individual variability in pathophysiology. To address this issue, the goal of our work, demonstrated in this study through four specific clinical applications, is to integrate multiple types of functional data into a consistent framework using multi-scale computational modelling. PMID:22670205

  17. Cardiac tamponade as the first clinical sign of gastric adenocarcinoma: a rare condition.

    PubMed

    Arısoy, Arif; Memiç, Kadriye; Karavelioğlu, Yusuf; Sen, Fatma

    2014-06-01

    Cardiac tamponade originating from a primary gastric cancer (GC) is a rare condition. Patients are generally asymptomatic until the disease is advanced. We report a rare patient with cardiac tamponade as the first manifestation of primary GC. A 46-year-old male was admitted with progressive dyspnea. Cardiac tamponade was diagnosed on two-dimensional ultrasonographic echocardiography. Pericardiocentesis yielded 1500 ml of bloody fluid. Pericardial cytologic examination was positive for malignant cells. The patient underwent abdominal computed tomography scan, which showed thickening of the gastric wall and several mesenteric lymph nodes. Endoscopic examination of the stomach disclosed malignant ulcer along the lesser curvature, and the biopsy showed diffuse type adenocarcinoma. Chemotherapy was initiated by the Oncology Department, and he had no pericardial effusion after six courses of systemic chemotherapy. In conclusion, this is a rare condition and difficult to diagnosis early. Thus, physicians should be aware of malignancy of the stomach when patients present with unexplained cardiac manifestations.

  18. Use of the single-breath method of estimating cardiac output during exercise-stress testing.

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    The single-breath cardiac output measurement technique of Kim et al. (1966) has been modified for use in obtaining cardiac output measurements during exercise-stress tests on Apollo astronauts. The modifications involve the use of a respiratory mass spectrometer for data acquisition and a digital computer program for data analysis. The variation of the modified method for triplicate steady-state cardiac output measurements was plus or minus 1 liter/min. The combined physiological and methodological variation seen during a set of three exercise tests on a series of subjects was 1 to 2.5 liter/min. Comparison of the modified method with the direct Fick technique showed that although the single-breath values were consistently low, the scatter of data was small and the correlation between the two methods was high. Possible reasons for the low single-breath cardiac output values are discussed.

  19. Cardiac haemangioma with coronary-pulmonary artery fistula in one patient.

    PubMed

    Xu, Hongfei; Li, Weidong; Teng, Peng; Ni, Yiming

    2015-02-01

    Cardiac haemangioma and coronary-pulmonary artery fistula are both rare entities. We present the case of a 45-year-old symptomatic male patient with a rare cardiac cavernous haemangioma. During assessment, coronary-pulmonary artery fistula was diagnosed by computed tomographic angiography (CTA) of the coronary artery. As far as we know, this is the first case in which cardiac haemangioma has been found to co-exist with coronary-pulmonary artery fistula. Surgery remains the most effective form of therapy. Meanwhile, in patients with heart issues, CTA of the coronary artery has its particularly advantages that can reduce the risk of a second operation and missed diagnosis. We also performed an electronic search of the published literature in English on cases of cardiac haemangioma.

  20. Reversible cardiac conduction block and defibrillation with high-frequency electric field.

    PubMed

    Tandri, Harikrishna; Weinberg, Seth H; Chang, Kelly C; Zhu, Renjun; Trayanova, Natalia A; Tung, Leslie; Berger, Ronald D

    2011-09-28

    Electrical impulse propagation is an essential function in cardiac, skeletal muscle, and nervous tissue. Abnormalities in cardiac impulse propagation underlie lethal reentrant arrhythmias, including ventricular fibrillation. Temporary propagation block throughout the ventricular myocardium could possibly terminate these arrhythmias. Electrical stimulation has been applied to nervous tissue to cause reversible conduction block, but has not been explored sufficiently in cardiac tissue. We show that reversible propagation block can be achieved in cardiac tissue by holding myocardial cells in a refractory state for a designated period of time by applying a sustained sinusoidal high-frequency alternating current (HFAC); in doing so, reentrant arrhythmias are terminated. We demonstrate proof of concept using several models, including optically mapped monolayers of neonatal rat ventricular cardiomyocytes, Langendorff-perfused guinea pig and rabbit hearts, intact anesthetized adult rabbits, and computer simulations of whole-heart impulse propagation. HFAC may be an effective and potentially safer alternative to direct current application, currently used to treat ventricular fibrillation.

  1. Using Data to Improve Quality: the Pediatric Cardiac Care Consortium.

    PubMed

    Moller, James H

    2016-01-01

    A program to collect and analyze cardiac catheterization, electrophysiologic studies and cardiac operations in children was initiated in 1982. The purpose was to help centers compare their experience and outcomes with a group of centers to determine areas where their performance might improve. Cardiac centers became members of the Pediatric Cardiac Care Consortium and submitted demographic data and copies of procedure reports regularly to a central office. Data were extracted from the reports, coded by trained coders and entered into a computer database. Annually, the data were analyzed to compare the experience of an individual center with that of the entire group of centers. The annual data were adjusted for severity on the basis of eight factors selected after discussion with participants in the Consortium. Adjustment was by multivariate analysis. Reports were prepared for each center and distributed at an annual meeting. The data were used by centers to review operations where the mortality rate exceeded +2 standard deviations of the group. With discussion, the center staff often initiated changes to improve outcome. The outcome could then be monitored by the annual reports. Our data were also utilized in the creation of the Risk Adjustment for Surgery for Congenital Heart Disease (RACHS)-1 categories of disease severity. The mortality rates of our centers were comparable with the combined hospital discharge data from New York, Massachusetts, and California. From 1982 through 2007, the mortality rates of our centers dropped for each RACHS-1 category, falling to less than 1% for categories 1 and 2 for the last 5-year period. During the 25 years, we received data from 52 centers about 137 654 patients who underwent 117 756 cardiac operations.

  2. Cardiac rehabilitation improves the blood plasma properties of cardiac patients.

    PubMed

    Gwoździński, Krzysztof; Pieniążek, Anna; Czepas, Jan; Brzeszczyńska, Joanna; Jegier, Anna; Pawlicki, Lucjan

    2016-11-01

    Cardiac rehabilitation (CR) improves exercise tolerance and general function. However, its effects on blood plasma in cardiac patients remain uncertain. Our aim was to examine the effect of comprehensive CR on the oxidative stress parameters and antioxidant plasma status in patients with coronary artery disease (CAD) after cardiac interventions. Exercise-based rehabilitation was established as ergometer training, adjusted for individual patients' physical efficiency. Training was repeated three times a week for two months. The standard biochemical (total cholesterol, HDL, LDL, triglycerides and erythrocyte sedimentation rate) and metabolic parameters (peak oxygen uptake [VO2] and peak workload) were determined. We assessed plasma viscosity, lipid peroxidation, carbonyl compounds levels, glutathione (GSH) and ascorbate (ASC) levels and the non-enzymatic antioxidant capacity of plasma in 12 patients with CAD before and after CR. Parameters were examined before exercise, immediately after exercise, and 1 h later. We also compared morphological and biochemical parameters of blood, as well as other parameters such as heart rate and blood pressure (resting and exercise), VO2max and peak workload (W) before and after CR. Before CR, a significant decrease in GSH concentration was observed 1 h after exercise. Conversely, after CR, GSH, and ASC levels remained unchanged immediately after exercise. However, ASC increased after CR after exercise and 1 h later in comparison to before CR. There was a significant increase in ferric reduction ability of plasma immediately after exercise after CR, when compared with before CR. CR improved several blood biochemical parameters, peak VO2, induced an increase in systolic blood pressure peak, and patients' peak workload. After CR, improvements were detected in oxidative stress parameters, except in the level of carbonyls. These changes may contribute to the increased functional heart capacity and better tolerance to exercise and

  3. A generic approach towards finite growth with examples of athlete's heart, cardiac dilation, and cardiac wall thickening

    NASA Astrophysics Data System (ADS)

    Göktepe, Serdar; Abilez, Oscar John; Kuhl, Ellen

    2010-10-01

    The objective of this work is to establish a generic continuum-based computational concept for finite growth of living biological tissues. The underlying idea is the introduction of an incompatible growth configuration which naturally introduces a multiplicative decomposition of the deformation gradient into an elastic and a growth part. The two major challenges of finite growth are the kinematic characterization of the growth tensor and the identification of mechanical driving forces for its evolution. Motivated by morphological changes in cell geometry, we illustrate a micromechanically motivated ansatz for the growth tensor for cardiac tissue that can capture both strain-driven ventricular dilation and stress-driven wall thickening. Guided by clinical observations, we explore three distinct pathophysiological cases: athlete's heart, cardiac dilation, and cardiac wall thickening. We demonstrate the computational solution of finite growth within a fully implicit incremental iterative Newton-Raphson based finite element solution scheme. The features of the proposed approach are illustrated and compared for the three different growth pathologies in terms of a generic bi-ventricular heart model.

  4. Quasiperiodicity route to chaos in cardiac conduction model

    NASA Astrophysics Data System (ADS)

    Quiroz-Juárez, M. A.; Vázquez-Medina, R.; Ryzhii, E.; Ryzhii, M.; Aragón, J. L.

    2017-01-01

    It has been suggested that cardiac arrhythmias are instances of chaos. In particular that the ventricular fibrillation is a form of spatio-temporal chaos that arises from normal rhythm through a quasi-periodicity or Ruelle-Takens-Newhouse route to chaos. In this work, we modify the heterogeneous oscillator model of cardiac conduction system proposed in Ref. [Ryzhii E, Ryzhii M. A heterogeneous coupled oscillator model for simulation of ECG signals. Comput Meth Prog Bio 2014;117(1):40-49. doi:10.1016/j.cmpb.2014.04.009.], by including an ectopic pacemaker that stimulates the ventricular muscle to model arrhythmias. With this modification, the transition from normal rhythm to ventricular fibrillation is controlled by a single parameter. We show that this transition follows the so-called torus of quasi-periodic route to chaos, as verified by using numerical tools such as power spectrum and largest Lyapunov exponent.

  5. Gated MRI of cardiac and paracardiac masses: initial experience

    SciTech Connect

    Amparo, E.G.; Higgins, C.B.; Farmer, D.; Gamsu, G.; McNamara, M.

    1984-12-01

    Ten cardiac and paracardiac masses were studied with magnetic resonance imaging (MRI) to evaluate the utility of this new method for determining the nature, location, and extent of such masses. The masses were intramural lesions (two cases), left atrial thrombus (one case), pericardial cysts (three cases), and mediastinal masses deforming and displacing the left atrium (two cases). ECG-gated images were obtained in all patients. In each of nine cases, MRI determined the location of the mass as intracavitary, intramural, or paracardiac, without the need for exogenous contrast material. This initial experience suggests that MRI can provide as much information as echocardiography, computed tomography, and angiography combined in the evaluation of cardiac and paracardiac masses.

  6. Proceedings of the cardiac PET summit meeting 12 may 2014: Cardiac PET and SPECT instrumentation.

    PubMed

    Garcia, Ernest V

    2015-06-01

    Advances in PET and SPECT and imaging hardware and software are vastly improving the noninvasive evaluation of myocardial perfusion and function. PET perfusion imaging has benefitted from the introduction of novel detectors that now allow true 3D imaging, and precise attenuation correction (AC). These developments have also resulted in perfusion images with higher spatial and contrast resolution that may be acquired in shorter protocols and/or with less patient radiation exposure than traditional PET or SPECT studies. Hybrid PET/CT cameras utilize transmission computed tomographic (CT) scans for AC, and offer the additional clinical advantages of evaluating coronary calcium and myocardial anatomy but at a higher cost than PET scanners that use (68)Ge radioactive line sources. As cardiac PET systems continue to improve, dedicated cardiac SPECT systems are also undergoing a profound change in their design. The scintillation camera general purpose design is being replaced with systems with multiple detectors focused on the heart yielding 5 to 10 times the sensitivity of conventional SPECT. As a result, shorter acquisition times and/or lower tracer doses produce higher quality SPECT images than were possible before. This article reviews these concepts and compares the attributes of PET and SPECT instrumentation.

  7. An integrated platform for image-guided cardiac resynchronization therapy

    NASA Astrophysics Data System (ADS)

    Ma, Ying Liang; Shetty, Anoop K.; Duckett, Simon; Etyngier, Patrick; Gijsbers, Geert; Bullens, Roland; Schaeffter, Tobias; Razavi, Reza; Rinaldi, Christopher A.; Rhode, Kawal S.

    2012-05-01

    Cardiac resynchronization therapy (CRT) is an effective procedure for patients with heart failure but 30% of patients do not respond. This may be due to sub-optimal placement of the left ventricular (LV) lead. It is hypothesized that the use of cardiac anatomy, myocardial scar distribution and dyssynchrony information, derived from cardiac magnetic resonance imaging (MRI), may improve outcome by guiding the physician for optimal LV lead positioning. Whole heart MR data can be processed to yield detailed anatomical models including the coronary veins. Cine MR data can be used to measure the motion of the LV to determine which regions are late-activating. Finally, delayed Gadolinium enhancement imaging can be used to detect regions of scarring. This paper presents a complete platform for the guidance of CRT using pre-procedural MR data combined with live x-ray fluoroscopy. The platform was used for 21 patients undergoing CRT in a standard catheterization laboratory. The patients underwent cardiac MRI prior to their procedure. For each patient, a MRI-derived cardiac model, showing the LV lead targets, was registered to x-ray fluoroscopy using multiple views of a catheter looped in the right atrium. Registration was maintained throughout the procedure by a combination of C-arm/x-ray table tracking and respiratory motion compensation. Validation of the registration between the three-dimensional (3D) roadmap and the 2D x-ray images was performed using balloon occlusion coronary venograms. A 2D registration error of 1.2 ± 0.7 mm was achieved. In addition, a novel navigation technique was developed, called Cardiac Unfold, where an entire cardiac chamber is unfolded from 3D to 2D along with all relevant anatomical and functional information and coupled to real-time device detection. This allowed more intuitive navigation as the entire 3D scene was displayed simultaneously on a 2D plot. The accuracy of the unfold navigation was assessed off-line using 13 patient data sets

  8. Progeria syndrome with cardiac complications.

    PubMed

    Ilyas, Saadia; Ilyas, Hajira; Hameed, Abdul; Ilyas, Muhammad

    2013-09-01

    A case report of 6-year-old boy with progeria syndrome, with marked cardiac complications is presented. The boy had cardiorespiratory failure. Discoloured purpuric skin patches, alopecia, prominent forehead, protuberant eyes, flattened nasal cartilage, malformed mandible, hypodentition, and deformed rigid fingers and toes were observed on examination. The boy was unable to speak. A sclerotic systolic murmur was audible over the mitral and aortic areas. Chest x-rays showed cardiac enlargement and the electrocardiogram (ECG) showed giant peaked P waves (right atrial hypertrophy) and right ventricular hypertrophy. Atherosclerotic dilated ascending aorta, thickened sclerotic aortic, mitral, and tricuspid valves with increased echo texture, left and right atrial and right ventricular dilatation, reduced left ventricular cavity, and thickened speckled atrial and ventricular septa were observed on echocardiography.

  9. Systems biology and cardiac arrhythmias.

    PubMed

    Grace, Andrew A; Roden, Dan M

    2012-10-27

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence.

  10. [Cardiac toxicity of 5-fluorouracil].

    PubMed

    Fournier, C; Benahmed, M; Blondeau, M

    1989-02-01

    A 67 year-old patient receives 5-fluorouracil for vocal chord cancer. During the perfusion, atypical angina pain occurs, accompanied with offset of ST above the baseline in standard leads and in V4 through V6. The pain subsides spontaneously in 45 minutes. These ECG alterations are followed 48 hours later by diffuse inverted T waves with lengthened QT. Cardiac ultrasonography and isotopic angiography do not show any abnormality of the left ventricular function, but myocardial tomoscintigraphy with labelled thallium show a lower hypofixation on exertion. The cardiac toxicity of 5-fluorouracil is in frequent. It is usually believed that it involves a coronary spasm, as suggested by the ECG tracing in the reported cases. The incident, which may be painful or painless, may result in a myocardial infarction or even sudden death during the perfusion. Therefore, it is advisable to discontinue the treatment as soon as an angina-type pain occurs.

  11. Minimum Information about a Cardiac Electrophysiology Experiment (MICEE): standardised reporting for model reproducibility, interoperability, and data sharing.

    PubMed

    Quinn, T A; Granite, S; Allessie, M A; Antzelevitch, C; Bollensdorff, C; Bub, G; Burton, R A B; Cerbai, E; Chen, P S; Delmar, M; Difrancesco, D; Earm, Y E; Efimov, I R; Egger, M; Entcheva, E; Fink, M; Fischmeister, R; Franz, M R; Garny, A; Giles, W R; Hannes, T; Harding, S E; Hunter, P J; Iribe, G; Jalife, J; Johnson, C R; Kass, R S; Kodama, I; Koren, G; Lord, P; Markhasin, V S; Matsuoka, S; McCulloch, A D; Mirams, G R; Morley, G E; Nattel, S; Noble, D; Olesen, S P; Panfilov, A V; Trayanova, N A; Ravens, U; Richard, S; Rosenbaum, D S; Rudy, Y; Sachs, F; Sachse, F B; Saint, D A; Schotten, U; Solovyova, O; Taggart, P; Tung, L; Varró, A; Volders, P G; Wang, K; Weiss, J N; Wettwer, E; White, E; Wilders, R; Winslow, R L; Kohl, P

    2011-10-01

    Cardiac experimental electrophysiology is in need of a well-defined Minimum Information Standard for recording, annotating, and reporting experimental data. As a step towards establishing this, we present a draft standard, called Minimum Information about a Cardiac Electrophysiology Experiment (MICEE). The ultimate goal is to develop a useful tool for cardiac electrophysiologists which facilitates and improves dissemination of the minimum information necessary for reproduction of cardiac electrophysiology research, allowing for easier comparison and utilisation of findings by others. It is hoped that this will enhance the integration of individual results into experimental, computational, and conceptual models. In its present form, this draft is intended for assessment and development by the research community. We invite the reader to join this effort, and, if deemed productive, implement the Minimum Information about a Cardiac Electrophysiology Experiment standard in their own work.

  12. Chaos control of cardiac arrhythmias.

    PubMed

    Garfinkel, A; Weiss, J N; Ditto, W L; Spano, M L

    1995-01-01

    Chaos theory has shown that many disordered and erratic phenomena are in fact deterministic, and can be understood causally and controlled. The prospect that cardiac arrhythmias might be instances of deterministic chaos is therefore intriguing. We used a recently developed method of chaos control to stabilize a ouabain-induced arrhythmia in rabbit ventricular tissue in vitro. Extension of these results to clinically significant arrhythmias such as fibrillation will require overcoming the additional obstacles of spatiotemporal complexity.

  13. Strategic Planning for Cardiac Services

    DTIC Science & Technology

    2008-04-13

    under a process review. 15. SUBJECT TERMS Strategy, Cardiac Services, DDEAMC, Dwight D. Eisenhower Army Medical Center 16. SECURITY CLASSIFICATION OF...each factor under a process review. CT Strategy Plan Table of Contents 1. Introduction 6 Conditions Which Prompted the Study 7 Statement of the...awareness of the program. Legal and administrative issues were seen in the consult process with Humana, the Tricare contractor for region South. Tricare

  14. Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization

    NASA Astrophysics Data System (ADS)

    Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

    2015-08-01

    The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress.

  15. Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization.

    PubMed

    Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

    2015-08-19

    The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress.

  16. Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization

    PubMed Central

    Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

    2015-01-01

    The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress. PMID:26286628

  17. Prior image constrained image reconstruction in emerging computed tomography applications

    NASA Astrophysics Data System (ADS)

    Brunner, Stephen T.

    Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

  18. Mastocytosis presenting as cardiac emergency.

    PubMed

    Ridolo, Erminia; Triggiani, Massimo; Montagni, Marcello; Olivieri, Elisa; Ticinesi, Andrea; Nouvenne, Antonio; Magliacane, Diomira; de Crescenzo, Gennaro; Meschi, Tiziana

    2013-12-01

    Mastocytosis is characterised by clonal proliferation of mast cells in the skin and in various internal organs, and by symptoms related to an acute release of mast cell-derived mediators. In 20-30 % of patients, mastocytosis occurs without the typical skin lesions of urticaria pigmentosa that are usually the first clinical sign of the disease. In these patients, anaphylaxis is often the presenting sign of the disease. We report three cases in which a cardiac emergency (cardiac arrest or ventricular fibrillation) was the first clinical manifestation of anaphylaxis associated with systemic mastocytosis. All patients were men, none of them had previous episodes of anaphylaxis or other mediator-related symptoms, and none had major pre-existing cardiovascular condition. An eliciting factor was identified in one case (a wasp sting), but one was found in the other two. Elevation of the serum tryptase suggested a mastocytosis, which was confirmed by bone marrow biopsy. This case series demonstrates that cardiovascular emergencies may be presenting signs of mastocytosis, and that elevation of serum tryptase after an acute cardiac event, if confirmed under basal conditions, may be useful for diagnosing this disease.

  19. Inherited arrhythmias: The cardiac channelopathies

    PubMed Central

    Behere, Shashank P; Weindling, Steven N

    2015-01-01

    Ion channels in the myocardial cellular membrane are responsible for allowing the cardiac action potential. Genetic abnormalities in these channels can predispose to life-threatening arrhythmias. We discuss the basic science of the cardiac action potential; outline the different clinical entities, including information regarding overlapping diagnoses, touching upon relevant genetics, new innovations in screening, diagnosis, risk stratification, and management. The special considerations of sudden unexplained death and sudden infant death syndrome are discussed. Scientists and clinicians continue to reconcile the rapidly growing body of knowledge regarding the molecular mechanisms and genetics while continuing to improve our understanding of the various clinical entities and their diagnosis and management in clinical setting. Two separate searches were run on the National Center for Biotechnology Information's website. The first using the term cardiac channelopathies was run on the PubMed database using filters for time (published in past 5 years) and age (birth-18 years), yielding 47 results. The second search using the medical subject headings (MeSH) database with the search terms “Long QT Syndrome” (MeSH) and “Short QT Syndrome” (MeSH) and “Brugada Syndrome” (MeSH) and “Catecholaminergic Polymorphic Ventricular Tachycardia” (MeSH), applying the same filters yielded 467 results. The abstracts of these articles were studied, and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles where further explored and read in full. PMID:26556967

  20. Sudden cardiac death risk stratification.

    PubMed

    Deyell, Marc W; Krahn, Andrew D; Goldberger, Jeffrey J

    2015-06-05

    Arrhythmic sudden cardiac death (SCD) may be caused by ventricular tachycardia/fibrillation or pulseless electric activity/asystole. Effective risk stratification to identify patients at risk of arrhythmic SCD is essential for targeting our healthcare and research resources to tackle this important public health issue. Although our understanding of SCD because of pulseless electric activity/asystole is growing, the overwhelming majority of research in risk stratification has focused on SCD-ventricular tachycardia/ventricular fibrillation. This review focuses on existing and novel risk stratification tools for SCD-ventricular tachycardia/ventricular fibrillation. For patients with left ventricular dysfunction or myocardial infarction, advances in imaging, measures of cardiac autonomic function, and measures of repolarization have shown considerable promise in refining risk. Yet the majority of SCD-ventricular tachycardia/ventricular fibrillation occurs in patients without known cardiac disease. Biomarkers and novel imaging techniques may provide further risk stratification in the general population beyond traditional risk stratification for coronary artery disease alone. Despite these advances, significant challenges in risk stratification remain that must be overcome before a meaningful impact on SCD can be realized.

  1. Cardiac MRI in restrictive cardiomyopathy.

    PubMed

    Gupta, A; Singh Gulati, G; Seth, S; Sharma, S

    2012-02-01

    Restrictive cardiomyopathy (RCM) is a specific group of heart muscle disorders characterized by inadequate ventricular relaxation during diastole. This leads to diastolic dysfunction with relative preservation of systolic function. Although short axis systolic function is usually preserved in RCM, the long axis systolic function may be severely impaired. Confirmation of diagnosis and information regarding aetiology, extent of myocardial damage, and response to treatment requires imaging. Importantly, differentiation from constrictive pericarditis (CCP) is needed, as only the latter is managed surgically. Echocardiography is the initial cardiac imaging technique but cannot reliably suggest a tissue diagnosis; although recent advances, especially tissue Doppler imaging and spectral tracking, have improved its ability to differentiate RCM from CCP. Cardiac catheterization is the reference standard, but is invasive, two-dimensional, and does not aid myocardial characterization. Cardiac magnetic resonance (CMR) is a versatile technique providing anatomical, morphological and functional information. In recent years, it has been shown to provide important information regarding disease mechanisms, and also been found useful to guide treatment, assess its outcome and predict patient prognosis. This review describes the CMR features of RCM, appearances in various diseases, its overall role in patient management, and how it compares with other imaging techniques.

  2. The history of cardiac catheterization.

    PubMed

    Bourassa, Martial G

    2005-10-01

    The evolution of cardiac catheterization has occurred over at least four centuries. One of the first major steps was the description of the circulation of the blood by William Harvey in 1628. The next milestone was the measurement of arterial pressure by Stephen Hales, one century later. However, the 19th century represented the golden age of cardiovascular physiology, highlighted by the achievements of Carl Ludwig, Etienne-Jules Marey and Claude Bernard, among others. Human cardiac catheterization developed during the 20th century. The first right heart catheterization in a human was performed by Werner Forssmann on himself in 1929. Diagnostic cardiac catheterization was introduced by André Cournand and Dickinson Richards in the early 1940s, and selective coronary angiography was described by Mason Sones in the early 1960s. More recently, with the advent of catheter-based interventions, pioneered by Andreas Gruentzig in the late 1970s, there has been considerable progress in the refinement and expansion of these techniques. Currently, the Sones technique is used only infrequently, and coronary angiography and percutaneous coronary intervention rely mainly on percutaneous femoral and percutaneous radial artery approaches. On the occasion of the 50th anniversary of the Montreal Heart Institute, it seems appropriate to highlight the contribution of this institution in these two areas.

  3. Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

    PubMed

    van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

    2015-01-01

    Non-invasive electrocardiographic imaging (ECGI) of the cardiac muscle can help the pre-procedure planning of the ablation of ventricular arrhythmias by reducing the time to localize the origin. Our non-invasive ECGI system, the cardiac isochrone positioning system (CIPS), requires non-intersecting meshes of the heart, lungs and torso. However, software to reconstruct the meshes of the heart, lungs and torso with the capability to check and prevent these intersections is currently lacking. Consequently the reconstruction of a patient specific model with realistic atrial and ventricular wall thickness and incorporating blood cavities, lungs and torso usually requires additional several days of manual work. Therefore new software was developed that checks and prevents any intersections, and thus enables the use of accurate reconstructed anatomical models within CIPS. In this preliminary study we investigated the accuracy of the created patient specific anatomical models from MRI or CT. During the manual segmentation of the MRI data the boundaries of the relevant tissues are determined. The resulting contour lines are used to automatically morph reference meshes of the heart, lungs or torso to match the boundaries of the morphed tissue. Five patients were included in the study; models of the heart, lungs and torso were reconstructed from standard cardiac MRI images. The accuracy was determined by computing the distance between the segmentation contours and the morphed meshes. The average accuracy of the reconstructed cardiac geometry was within 2mm with respect to the manual segmentation contours on the MRI images. Derived wall volumes and left ventricular wall thickness were within the range reported in literature. For each reconstructed heart model the anatomical heart axis was computed using the automatically determined anatomical landmarks of the left apex and the mitral valve. The accuracy of the reconstructed heart models was well within the accuracy of the used

  4. Spontaneous left main coronary artery dissection complicated by pseudoaneurysm formation in pregnancy: role of CT coronary angiography.

    PubMed

    Rahman, Shahid; Abdul-Waheed, Mohammed; Helmy, Tarek; Huffman, Lynn C; Koshal, Vipin; Guitron, Julian; Merrill, Walter H; Lewis, David F; Dunlap, Stephanie; Shizukuda, Yukitaka; Weintraub, Neal L; Meyer, Christopher; Cilingiroglu, Mehmet

    2009-04-01

    We report a case of a 26-year-old female, who presented at 34 weeks of an uncomplicated pregnancy with an acute ST elevation anterior wall myocardial infarction. Cardiac catheterization suggested a left main coronary artery dissection with pseudoaneurysm formation. The patient's course was complicated by congestive heart failure. She was initially managed conservatively by a multidisciplinary team including heart failure specialists, obstetricians, and cardiovascular surgeons. 4 days after admission, her LMC was imaged by dual-source 64 slice Cardiac computed tomography, coronary dissection was identified extending to the lumen, and the presence of pseudoaneurysm was confirmed. She underwent subsequently a staged procedure, which included placement of an intra-aortic balloon pump, cesarean section, and coronary artery bypass grafting. This case illustrates the utility of coronary artery CT imaging to assess the complexity and stability of coronary artery dissections, thereby helping to determine the need for, and timing of revascularization procedures.

  5. Robotic cardiac surgery in Brazil

    PubMed Central

    Toschi, Alisson P.; Pope, Renato B.; Montanhesi, Paola K.; Santos, Ricardo S.; Teruya, Alexandre; Hatanaka, Dina M.; Rusca, Gabriel F.; Fischer, Claudio H.; Vieira, Marcelo C.; Makdisse, Marcia R.

    2017-01-01

    Background Brazil, the largest country and economy in South America, is a major driving force behind the development of new medical technologies in the region. Robotic cardiac surgery (RCS) has been evolving rapidly since 2010, when the first surgery using the DaVinci® robotic system was performed in Latin America. The aim of this article is to evaluate short and mid-term results in patients undergoing robotic cardiac surgery in Brazil. Methods From March 2010 to December 2015, 39 consecutive patients underwent robotic cardiac surgery. Twenty-seven patients were male (69.2%), with the mean age of 51.3±17.9 years. Participants had a mean ejection fraction of 62±5%. The procedures included in this study were mitral valve surgery, surgical treatment of atrial fibrillation, atrial septal defect closure, resection of intra-cardiac tumors, totally endoscopic coronary artery bypass and pericardiectomy. Results The mean time spent on cardiopulmonary bypass (CPB) during RCS was 154.9±94.2 minutes and the mean aortic cross-clamp time was 114.48±75.66 minutes. Thirty-two patients (82%) were extubated in the operating room immediately after surgery. The median intensive care unit (ICU) length of stay was 1 day (ranging from 0 to 25) and the median hospital length of stay was 5 days (ranging from 3 to 25). For each type of procedure, endpoints were individually reported. There were no conversions to sternotomy and no intra-operative complications. Patient follow-up was complete in 100% of the participants, with two early deaths unrelated to the procedures and no re-operations at mid-term. Conclusions Despite the heterogeneity of this series, RCS appears to be feasible, safe and effective when used for the correction of various intra- and extra-cardiac pathologies. Adopting the robotic system has been a challenge in Brazil, where its limited clinical application may be related to the lack of specific training and the high cost of technology. PMID:28203537

  6. Mitochondria in cardiac hypertrophy and heart failure

    PubMed Central

    Rosca, Mariana G.; Tandler, Bernard; Hoppel, Charles L.

    2013-01-01

    Heart failure (HF) frequently is the unfavorable outcome of pathological heart hypertrophy. In contrast to physiological cardiac hypertrophy, which occurs in response to exercise and leads to full adaptation of contractility to the increased wall stress, pathological hypertrophy occurs in response to volume or pressure overload, ultimately leading to contractile dysfunction and HF. Because cardiac hypertrophy impairs the relationship between ATP demand and production, mitochondrial bioenergetics must keep up with the cardiac hypertrophic phenotype. We review data regarding the mitochondrial proteomic and energetic remodeling in cardiac hypertrophy, as well as the temporal and causal relationship between mitochondrial failure to match the increased energy demand and progression to cardiac decompensation. We suggest that the maladaptive effect of sustained neuroendocrine signals on mitochondria leads to bioenergetic fading which contributes to the progression from cardiac hypertrophy to failure. PMID:22982369

  7. Cardiac mechanics: Physiological, clinical, and mathematical considerations

    NASA Technical Reports Server (NTRS)

    Mirsky, I. (Editor); Ghista, D. N.; Sandler, H.

    1974-01-01

    Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

  8. Quality Control Systems in Cardiac Aging

    PubMed Central

    Quarles, Ellen K; Dai, Dao-Fu; Tocchi, Autumn; Basisty, Nathan; Gitari, Lemuel; Rabinovitch, Peter S

    2015-01-01

    Cardiac aging is an intrinsic process that results in impaired cardiac function, along with cellular and molecular changes. These degenerative changes are intimately associated with quality control mechanisms. This review provides a general overview of the clinical and cellular changes which manifest in cardiac aging, and the quality control mechanisms involved in maintaining homeostasis and retarding aging. These mechanisms include autophagy, ubiquitin-mediated turnover, apoptosis, mitochondrial quality control and cardiac matrix homeostasis. Finally, we discuss aging interventions that have been observed to impact cardiac health outcomes. These include caloric restriction, rapamycin, resveratrol, GDF11, mitochondrial antioxidants and cardiolipin-targeted therapeutics. A greater understanding of the quality control mechanisms that promote cardiac homeostasis will help to understand the benefits of these interventions, and hopefully lead to further improved therapeutic modalities. PMID:25702865

  9. Radiation Dose and Safety in Cardiac Computed Tomography

    PubMed Central

    Gerber, Thomas C; Kantor, Birgit; McCollough, Cynthia H.

    2009-01-01

    Synopsis As a result of the changes in utilization of imaging procedures that rely on ionizing radiation, the collective dose has increased by over 700% and the annual per-capita dose, by almost 600% over recent years. It is certainly possible that this growing use may have significant effects on public health. Although there are uncertainties related to the accuracy of calculated radiation exposure and the estimated biologic risk, there are measures that can be taken to reduce any potential risks while maintaining diagnostic accuracy. This article will review the existing data regarding biological hazards of radiation exposure associated to medical diagnostic testing, the methodology used to estimate radiation exposure and the measures that can be taken to effectively reduce it. PMID:19766923

  10. Analysis of the Total Surgical Cardiac Denervation by Computer Simulation

    DTIC Science & Technology

    2007-11-02

    filtration rate and increase vasopressin, plasma renin activity, angiotensin II and aldosteron” [2][3]. It is claimed that these effects weaken...CE: Chemoreceptor Effect OSR: Autonomous System Resp. CK: Potassium Concent PPC: Plasma Osmotic Pressure CNa: Sodium Concentration RAP: Right...receptors respond to hypervolemia by supressing vasopressin, renin - angiotensin-aldosteron axis, thirst and sympathetic traffic to the kidney

  11. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Body mass index. (iv) Systolic blood pressure. (v) Diastolic blood pressure. (vi) The need for cholesterol, blood pressure, and diabetes medications. (3) A list of approved intensive cardiac rehabilitation... prescribed exercise, cardiac risk factor modification, psychosocial assessment, and outcomes...

  12. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Body mass index. (iv) Systolic blood pressure. (v) Diastolic blood pressure. (vi) The need for cholesterol, blood pressure, and diabetes medications. (3) A list of approved intensive cardiac rehabilitation... prescribed exercise, cardiac risk factor modification, psychosocial assessment, and outcomes...

  13. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Body mass index. (iv) Systolic blood pressure. (v) Diastolic blood pressure. (vi) The need for cholesterol, blood pressure, and diabetes medications. (3) A list of approved intensive cardiac rehabilitation... prescribed exercise, cardiac risk factor modification, psychosocial assessment, and outcomes...

  14. Enhanced sympathetic cardiac modulation in bruxism patients.

    PubMed

    Marthol, Harald; Reich, Sven; Jacke, Julia; Lechner, Karl-Heinz; Wichmann, Manfred; Hilz, Max Josef

    2006-08-01

    Sleep bruxism, an oral parafunction including teeth clenching and grinding, might be related to increased stress. To evaluate sympathetic cardiac activity in bruxism patients, we monitored cardiac autonomic modulation using spectral analysis of heart rate variability and compared results to those of age-matched healthy volunteers. In bruxism patients, sympathetic cardiac activity was higher than in volunteers. The increased sympathetic tone suggests increased stress and might be related to occlusal disharmonies.

  15. Multiphysics and multiscale modelling, data–model fusion and integration of organ physiology in the clinic: ventricular cardiac mechanics

    PubMed Central

    Chabiniok, Radomir; Wang, Vicky Y.; Hadjicharalambous, Myrianthi; Asner, Liya; Lee, Jack; Sermesant, Maxime; Kuhl, Ellen; Young, Alistair A.; Moireau, Philippe; Nash, Martyn P.; Chapelle, Dominique

    2016-01-01

    With heart and cardiovascular diseases continually challenging healthcare systems worldwide, translating basic research on cardiac (patho)physiology into clinical care is essential. Exacerbating this already extensive challenge is the complexity of the heart, relying on its hierarchical structure and function to maintain cardiovascular flow. Computational modelling has been proposed and actively pursued as a tool for accelerating research and translation. Allowing exploration of the relationships between physics, multiscale mechanisms and function, computational modelling provides a platform for improving our understanding of the heart. Further integration of experimental and clinical data through data assimilation and parameter estimation techniques is bringing computational models closer to use in routine clinical practice. This article reviews developments in computational cardiac modelling and how their integration with medical imaging data is providing new pathways for translational cardiac modelling. PMID:27051509

  16. Multiphysics and multiscale modelling, data-model fusion and integration of organ physiology in the clinic: ventricular cardiac mechanics.

    PubMed

    Chabiniok, Radomir; Wang, Vicky Y; Hadjicharalambous, Myrianthi; Asner, Liya; Lee, Jack; Sermesant, Maxime; Kuhl, Ellen; Young, Alistair A; Moireau, Philippe; Nash, Martyn P; Chapelle, Dominique; Nordsletten, David A

    2016-04-06

    With heart and cardiovascular diseases continually challenging healthcare systems worldwide, translating basic research on cardiac (patho)physiology into clinical care is essential. Exacerbating this already extensive challenge is the complexity of the heart, relying on its hierarchical structure and function to maintain cardiovascular flow. Computational modelling has been proposed and actively pursued as a tool for accelerating research and translation. Allowing exploration of the relationships between physics, multiscale mechanisms and function, computational modelling provides a platform for improving our understanding of the heart. Further integration of experimental and clinical data through data assimilation and parameter estimation techniques is bringing computational models closer to use in routine clinical practice. This article reviews developments in computational cardiac modelling and how their integration with medical imaging data is providing new pathways for translational cardiac modelling.

  17. [A basis for application of cardiac contractility variability in the Evaluation and assessment of exercise and fitness].

    PubMed

    Bu, Bin; Wang, Aihua; Han, Haijun; Xiao, Shouzhong

    2010-06-01

    Cardiac contractility variability (CCV) is a new concept which is introduced in the research field of cardiac contractility in recent years, that is to say, there are some disparities between cardiac contractilities when heart contracts. The changing signals of cardiac contractility contain a plenty of information on the cardiovascular function and disorder. In order to collect and analyze the message, we could quantitatively evaluate the tonicity and equilibrium of cardiac sympathetic nerve and parasympathetic nerve, and the effects of bio-molecular mechanism on the cardiovascular activities. By analyzing CCV, we could further understand the background of human being's heritage characteristics, nerve types, the adjusting mechanism, the molecular biology, and the adjustment of cardiac automatic nerve. With the development of the computing techniques, the digital signal processing method and its application in medical field, this analysis has been progressing greatly. By now, the assessment of CCV, just like the analysis of heart rate variability, is mainly via time domain and frequency domain analysis. CCV is one of the latest research fields in human cardiac signals being scarcely reported in the field of sports medicine; however, its research progresses are of important value for cardiac physiology and pathology in sports medicine and rehabilitation medicine.

  18. A cardiac electrical activity model based on a cellular automata system in comparison with neural network model.

    PubMed

    Khan, Muhammad Sadiq Ali; Yousuf, Sidrah

    2016-03-01

    Cardiac Electrical Activity is commonly distributed into three dimensions of Cardiac Tissue (Myocardium) and evolves with duration of time. The indicator of heart diseases can occur randomly at any time of a day. Heart rate, conduction and each electrical activity during cardiac cycle should be monitor non-invasively for the assessment of "Action Potential" (regular) and "Arrhythmia" (irregular) rhythms. Many heart diseases can easily be examined through Automata model like Cellular Automata concepts. This paper deals with the different states of cardiac rhythms using cellular automata with the comparison of neural network also provides fast and highly effective stimulation for the contraction of cardiac muscles on the Atria in the result of genesis of electrical spark or wave. The specific formulated model named as "States of automaton Proposed Model for CEA (Cardiac Electrical Activity)" by using Cellular Automata Methodology is commonly shows the three states of cardiac tissues conduction phenomena (i) Resting (Relax and Excitable state), (ii) ARP (Excited but Absolutely refractory Phase i.e. Excited but not able to excite neighboring cells) (iii) RRP (Excited but Relatively Refractory Phase i.e. Excited and able to excite neighboring cells). The result indicates most efficient modeling with few burden of computation and it is Action Potential during the pumping of blood in cardiac cycle.

  19. Cardiac Arrhythmias: Diagnosis, Symptoms, and Treatments.

    PubMed

    Fu, Du-Guan

    2015-11-01

    The cardiac arrhythmia is characterized by irregular rhythm of heartbeat which could be either too slow (<60 beats/min) or too fast (>100 beats/min) and can happen at any age. The use of pacemaker and defibrillators devices has been suggested for heart arrhythmias patients. The antiarrhythmic medications have been reported for the treatment of cardiac arrhythmias or irregular heartbeats. The diagnosis, symptoms, and treatments of cardiac arrhythmias as well as the radiofrequency ablation, tachycardia, Brugada syndrome, arterial fibrillation, and recent research on the genetics of cardiac arrhythmias have been described here.

  20. Sudden cardiac death – Historical perspectives

    PubMed Central

    Abhilash, S.P.; Namboodiri, Narayanan

    2014-01-01

    Sudden cardiac death (SCD) is an unexpected death due to cardiac causes that occurs in a short time period (generally within 1 h of symptom onset) in a person with known or unknown cardiac disease. It is believed to be involved in nearly a quarter of human deaths, with ventricular fibrillation being the most common mechanism. It is estimated that more than 7 million lives per year are lost to SCD worldwide. Historical perspectives of SCD are analyzed with a brief description on how the developments in the management of sudden cardiac arrest evolved over time. PMID:24568828

  1. Cardiac tissue engineering in magnetically actuated scaffolds

    NASA Astrophysics Data System (ADS)

    Sapir, Yulia; Polyak, Boris; Cohen, Smadar

    2014-01-01

    Cardiac tissue engineering offers new possibilities for the functional and structural restoration of damaged or lost heart tissue by applying cardiac patches created in vitro. Engineering such functional cardiac patches is a complex mission, involving material design on the nano- and microscale as well as the application of biological cues and stimulation patterns to promote cell survival and organization into a functional cardiac tissue. Herein, we present a novel strategy for creating a functional cardiac patch by combining the use of a macroporous alginate scaffold impregnated with magnetically responsive nanoparticles (MNPs) and the application of external magnetic stimulation. Neonatal rat cardiac cells seeded within the magnetically responsive scaffolds and stimulated by an alternating magnetic field of 5 Hz developed into matured myocardial tissue characterized by anisotropically organized striated cardiac fibers, which preserved its features for longer times than non-stimulated constructs. A greater activation of AKT phosphorylation in cardiac cell constructs after applying a short-term (20 min) external magnetic field indicated the efficacy of magnetic stimulation to actuate at a distance and provided a possible mechanism for its action. Our results point to a synergistic effect of magnetic field stimulation together with nanoparticulate features of the scaffold surface as providing the regenerating environment for cardiac cells driving their organization into functionally mature tissue.

  2. Preload Sensitivity in Cardiac Assist Devices

    PubMed Central

    Fukamachi, Kiyotaka; Shiose, Akira; Massiello, Alex; Horvath, David J.; Golding, Leonard A. R.; Lee, Sangjin; Starling, Randall C.

    2013-01-01

    With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to understand the unique physiology of device-assisted circulation. Preload sensitivity as it relates to cardiac assist devices is derived from the Frank-Starling relationship between human ventricular filling pressures and ventricular stroke volume. In this review, we stratify the preload sensitivity of 17 implantable cardiac assist devices relative to the native heart and discuss the effect of preload sensitivity on left ventricular volume unloading, levels of cardiac support, and the future development of continuous-flow total artificial heart technology. PMID:23272869

  3. Cardiac aetiology of cardiac arrest: percutaneous coronary interventions during and after cardiopulmonary resuscitation.

    PubMed

    Nikolaou, Nikolaos I; Christou, Apostolos H

    2013-09-01

    Management and prevention of cardiac arrest in the setting of heart disease is a challenge for modern cardiology. After reviewing the aetiology of sudden cardiac death and discussing the way to identify candidates at risk, we emphasise the role of percutaneous coronary interventions during and after cardiopulmonary resuscitation in the treatment of patients with return of spontaneous circulation after cardiac arrest.

  4. Brain responses to cardiac electrical stimulation: a new EEG method for evaluating cardiac sensation.

    PubMed

    Suzuki, Hideaki; Hirose, Masanori; Watanabe, Satoshi; Fukuda, Koji; Fukudo, Shin; Shimokawa, Hiroaki

    2012-01-01

    Although cardiac sensation, such as palpitation or chest pain, is common and is sometimes a malignant sign of heart diseases, the mechanism by which the human brain responds to afferent signals from the heart remains unclear. In this study, we investigated whether electrical stimulation of the heart provokes brain responses in humans. We examined 15 patients (age: 65.4 ± 3.1 years old, 11 males and 4 females) implanted with either a cardiac pacemaker or cardiac resynchronization therapy (CRT) device. Electroencephalogram (EEG) was simultaneously recorded from the vertex during right ventricular pacing at 70-100 beats/min at baseline (1.5 V) and intense (6-8 V) stimulation sessions. We evaluated brain responses to cardiac electrical stimulation by measuring cerebral potentials that were obtained by subtracting the average of 100 EEG waves triggered by cardiac pacing during baseline stimulation from those during the intense stimulation. Intense stimulation of the cardiac pacemaker or CRT device reproducibly induced cardiac sensation in 6 out of the 15 patients; namely, the remaining 9 patients showed no reproducible response. Brain responses were evident by averaging cerebral potentials from all of the 15 patients and those from 6 patients with reproducible cardiac sensation. To the best our knowledge, this is the first report that demonstrates the brain responses to cardiac electrical stimulation in humans. This new method should be useful for examining pathophysiology of cardiac diseases with pathological cardiac sensation, including cardiac anxiety and silent myocardial ischemia.

  5. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... heart-lung transplant. (vii) For cardiac rehabilitation only, other cardiac conditions as specified...) Body mass index. (iv) Systolic blood pressure. (v) Diastolic blood pressure. (vi) The need for cholesterol, blood pressure, and diabetes medications. (3) A list of approved intensive cardiac...

  6. 42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... heart-lung transplant. (vii) For cardiac rehabilitation only, other cardiac conditions as specified...) Body mass index. (iv) Systolic blood pressure. (v) Diastolic blood pressure. (vi) The need for cholesterol, blood pressure, and diabetes medications. (3) A list of approved intensive cardiac...

  7. Pathogenic peptide deviations support a model of adaptive evolution of chordate cardiac performance by troponin mutations

    PubMed Central

    Palpant, Nathan J.; Houang, Evelyne M.; Delport, Wayne; Hastings, Kenneth E. M.; Onufriev, Alexey V.; Sham, Yuk Y.

    2010-01-01

    In cardiac muscle, the troponin (cTn) complex is a key regulator of myofilament calcium sensitivity because it serves as a molecular switch required for translating myocyte calcium fluxes into sarcomeric contraction and relaxation. Studies of several species suggest that ectotherm chordates have myofilaments with heightened calcium responsiveness. However, genetic polymorphisms in cTn that cause increased myofilament sensitivity to activating calcium in mammals result in cardiac disease including arrhythmias, diastolic dysfunction, and increased susceptibility to sudden cardiac death. We hypothesized that specific residue modifications in the regulatory arm of troponin I (TnI) were critical in mediating the observed decrease in myofilament calcium sensitivity within the mammalian taxa. We performed large-scale phylogenetic analysis, atomic resolution molecular dynamics simulations and modeling, and computational alanine scanning. This study provides evidence that a His to Ala substitution within mammalian cardiac TnI (cTnI) reduced the thermodynamic potential at the interface between cTnI and cardiac TnC (cTnC) in the calcium-saturated state by disrupting a strong intermolecular electrostatic interaction. This key residue modification reduced myofilament calcium sensitivity by making cTnI molecularly untethered from cTnC. To meet the requirements for refined mammalian adult cardiac performance, we propose that compensatory evolutionary pressures favored mutations that enhanced the relaxation properties of cTn by decreasing its sensitivity to activating calcium. PMID:20423961

  8. Pathogenic peptide deviations support a model of adaptive evolution of chordate cardiac performance by troponin mutations.

    PubMed

    Palpant, Nathan J; Houang, Evelyne M; Delport, Wayne; Hastings, Kenneth E M; Onufriev, Alexey V; Sham, Yuk Y; Metzger, Joseph M

    2010-07-07

    In cardiac muscle, the troponin (cTn) complex is a key regulator of myofilament calcium sensitivity because it serves as a molecular switch required for translating myocyte calcium fluxes into sarcomeric contraction and relaxation. Studies of several species suggest that ectotherm chordates have myofilaments with heightened calcium responsiveness. However, genetic polymorphisms in cTn that cause increased myofilament sensitivity to activating calcium in mammals result in cardiac disease including arrhythmias, diastolic dysfunction, and increased susceptibility to sudden cardiac death. We hypothesized that specific residue modifications in the regulatory arm of troponin I (TnI) were critical in mediating the observed decrease in myofilament calcium sensitivity within the mammalian taxa. We performed large-scale phylogenetic analysis, atomic resolution molecular dynamics simulations and modeling, and computational alanine scanning. This study provides evidence that a His to Ala substitution within mammalian cardiac TnI (cTnI) reduced the thermodynamic potential at the interface between cTnI and cardiac TnC (cTnC) in the calcium-saturated state by disrupting a strong intermolecular electrostatic interaction. This key residue modification reduced myofilament calcium sensitivity by making cTnI molecularly untethered from cTnC. To meet the requirements for refined mammalian adult cardiac performance, we propose that compensatory evolutionary pressures favored mutations that enhanced the relaxation properties of cTn by decreasing its sensitivity to activating calcium.

  9. Helping Family Physicians Improve Their Cardiac Auscultation Skills with an Interactive CD-ROM.

    ERIC Educational Resources Information Center

    Roy, Douglas; Sargeant, Joan; Gray, Jean; Hoyt, Brian; Allen, Michael; Fleming, Michael

    2002-01-01

    Physicians (n=42) studied cardiac auscultation using a 15-hour CD-ROM program. Nine months later, 21 who completed a posttest showed significant improvement in identifying heart sounds. CDs were valued for opportunities to review material at an individual pace. Lack of computer skills hindered use. (Contains 26 references.) (SK)

  10. Micro-CT with respiratory and cardiac gating

    SciTech Connect

    Badea, C.; Hedlund, L.W.; Johnson, G.A.

    2004-12-01

    Cardiopulmonary imaging in rodents using micro-computed tomography (CT) is a challenging task due to both cardiac and pulmonary motion and the limited fluence rate available from micro-focus x-ray tubes of most commercial systems. Successful imaging in the mouse requires recognition of both the spatial and temporal scales and their impact on the required fluence rate. Smaller voxels require an increase in the total number of photons (integrated fluence) used in the reconstructed image for constant signal-to-noise ratio. The faster heart rates require shorter exposures to minimize cardiac motion blur imposing even higher demands on the fluence rate. We describe a system with fixed tube/detector and with a rotating specimen. A large focal spot x-ray tube capable of producing high fluence rates with short exposure times was used. The geometry is optimized to match focal spot blur with detector pitch and the resolution limits imposed by the reproducibility of gating. Thus, it is possible to achieve isotropic spatial resolution of 100 {mu}m with a fluence rate at the detector 250 times that of a conventional cone beam micro-CT system with rotating detector and microfocal x-ray tube. Motion is minimized for any single projection with 10 ms exposures that are synchronized to both cardiac and breathing motion. System performance was validated in vivo by studies of the cardiopulmonary structures in C57BL/6 mice, demonstrating the value of motion integration with a bright x-ray source.

  11. Exact coherent structures: from fluid turbulence to cardiac arrhythmias

    NASA Astrophysics Data System (ADS)

    Grigoriev, Roman; Marcotte, Christopher; Byrne, Gregory

    2014-03-01

    Ventricular fibrillation, a life threatening cardiac arrhythmia, is an example of spatiotemporally chaotic state dominated by multiple interacting spiral waves. Recent studies of weak fluid turbulence suggest that spatiotemporal chaos in general can be understood as a walk among exact unstable regular solutions (exact coherent states, ECS) of nonlinear evolution equations. Several classes of ECS are believed to play a dominant role; most typically these are equilibria and periodic orbits or relative equilibria and relative periodic orbits for systems with global continuous symmetries. Numerical methods originally developed in the context of fluid turbulence can also be applied to models of cardiac dynamics which possess translational and rotational symmetries and, indeed, allowed us to identify relative equilibria and periodic orbits describing isolated spirals with, respectively, fixed and drifting cores. In order to find regular solutions featuring multiple interacting spirals a new approach is required that takes into consideration the dynamics of slowly drifting cores associated with local, rather than global, symmetries. We describe how local symmetries can be reduced and more general types of ECS computed that dominate spiral wave chaos in models of cardiac tissue.

  12. Towards robust specularity detection and inpainting in cardiac images

    NASA Astrophysics Data System (ADS)

    Alsaleh, Samar M.; Aviles, Angelica I.; Sobrevilla, Pilar; Casals, Alicia; Hahn, James

    2016-03-01

    Computer-assisted cardiac surgeries had major advances throughout the years and are gaining more popularity over conventional cardiac procedures as they offer many benefits to both patients and surgeons. One obvious advantage is that they enable surgeons to perform delicate tasks on the heart while it is still beating, avoiding the risks associated with cardiac arrest. Consequently, the surgical system needs to accurately compensate the physiological motion of the heart which is a very challenging task in medical robotics since there exist different sources of disturbances. One of which is the bright light reflections, known as specular highlights, that appear on the glossy surface of the heart and partially occlude the field of view. This work is focused on developing a robust approach that accurately detects and removes those highlights to reduce their disturbance to the surgeon and the motion compensation algorithm. As a first step, we exploit both color attributes and Fuzzy edge detector to identify specular regions in each acquired image frame. These two techniques together work as restricted thresholding and are able to accurately identify specular regions. Then, in order to eliminate the specularity artifact and give the surgeon a better perception of the heart, the second part of our solution is dedicated to correct the detected regions using inpainting to propagate and smooth the results. Our experimental results, which we carry out in realistic datasets, reveal how efficient and precise the proposed solution is, as well as demonstrate its robustness and real-time performance.

  13. Two-dimensional Chebyshev pseudospectral modelling of cardiac propagation.

    PubMed

    Zhan, Z; Ng, K T

    2000-05-01

    Bidomain or monodomain modelling has been used widely to study various issues related to action potential propagation in cardiac tissue. In most of these previous studies, the finite difference method is used to solve the partial differential equations associated with the model. Though the finite difference approach has provided useful insight in many cases, adequate discretisation of cardiac tissue with realistic dimensions often requires a large number of nodes, making the numerical solution process difficult or impossible with available computer resources. Here, a Chebyshev pseudospectral method is presented that allows a significant reduction in the number of nodes required for a given solution accuracy. The new method is used to solve the governing nonlinear partial differential equation for the monodomain model representing a two-dimensional homogeneous sheet of cardiac tissue. The unknown transmembrane potential is expanded in terms of Chebyshev polynomial trial functions and the equation is enforced at the Gauss-Lobatto grid points. Spatial derivatives are obtained using the fast Fourier transform and the solution is advanced in time using an explicit technique. Numerical results indicate that the pseudospectral approach allows the number of nodes to be reduced by a factor of sixteen, while still maintaining the same error performance. This makes it possible to perform simulations with the same accuracy using about twelve times less CPU time and memory.

  14. Multi-formalism modelling and simulation: application to cardiac modelling

    PubMed Central

    Defontaine, Antoine; Hernández, Alfredo; Carrault, Guy

    2004-01-01

    Cardiovascular modelling has been a major research subject for the last decades. Different cardiac models have been developed at a cellular level as well as at the whole organ level. Most of these models are defined by a comprehensive cellular modelling using continuous formalisms or by a tissue-level modelling often based on discrete formalisms. Nevertheless, both views still suffer from difficulties that reduce their clinical applications: the first approach requires heavy computational resources while the second one is not able to reproduce certain pathologies. This paper presents an original methodology trying to gather advantages from both approaches, by means of an hybrid model mixing discrete and continuous formalisms. This method has been applied to define a hybrid model of cardiac action potential propagation on a 2D grid of endocardial cells, combining cellular automata and a set of cells defined by the Beeler Reuter model. For simulations under physiologic and ischemic conditions, results show that the action potential propagation as well as electrogram reconstructions are consistent with clinical diagnosis. Finally, the interest of the proposed approach is discussed within the frame of cardiac modelling and simulation. PMID:15520534

  15. ECLS in Pediatric Cardiac Patients

    PubMed Central

    Di Nardo, Matteo; MacLaren, Graeme; Marano, Marco; Cecchetti, Corrado; Bernaschi, Paola; Amodeo, Antonio

    2016-01-01

    Extracorporeal life support (ECLS) is an important device in the management of children with severe refractory cardiac and or pulmonary failure. Actually, two forms of ECLS are available for neonates and children: extracorporeal membrane oxygenation (ECMO) and use of a ventricular assist device (VAD). Both these techniques have their own advantages and disadvantages. The intra-aortic balloon pump is another ECLS device that has been successfully used in larger children, adolescents, and adults, but has found limited applicability in smaller children. In this review, we will present the “state of art” of ECMO in neonate and children with heart failure. ECMO is commonly used in a variety of settings to provide support to critically ill patients with cardiac disease. However, a strict selection of patients and timing of intervention should be performed to avoid the increase in mortality and morbidity of these patients. Therefore, every attempt should be done to start ECLS “urgently” rather than “emergently,” before the presence of dysfunction of end organs or circulatory collapse. Even though exciting progress is being made in the development of VADs for long-term mechanical support in children, ECMO remains the mainstay of mechanical circulatory support in children with complex anatomy, particularly those needing rapid resuscitation and those with a functionally univentricular circulation. With the increase in familiarity with ECMO, new indications have been added, such as extracorporeal cardiopulmonary resuscitation (ECPR). The literature supporting ECPR is increasing in children. Reasonable survival rates have been achieved after initiation of support during active compressions of the chest following in-hospital cardiac arrest. Contraindications to ECLS have reduced in the last 5 years and many centers support patients with functionally univentricular circulations. Improved results have been recently achieved in this complex subset of patients. PMID

  16. Acute pericarditis with cardiac tamponade induced by pacemaker implantation.

    PubMed

    Shingaki, Masami; Kobayashi, Yutaka; Suzuki, Haruo

    2015-11-01

    An 87-year-old woman was diagnosed with third-degree atrioventricular block and underwent pacemaker implantation. On postoperative day 12, she experienced cardiac tamponade that was suspected on computed tomography to be caused by lead perforation; therefore, we performed open-heart surgery. However, we could not identify a perforation site on the heart, and drained a 400-mL exudative pericardial effusion. Subsequently, we diagnosed the pericardial effusion as due to pericarditis induced by pacemaker implantation. It is sometimes difficult to distinguish pericarditis from pacemaker lead perforation, so both should be included in the differential diagnosis.

  17. Autopsy imaging for cardiac tamponade in a Thoroughbred foal.

    PubMed

    Yamada, Kazutaka; Sato, Fumio; Horiuchi, Noriyuki; Higuchi, Tohru; Kobayashi, Yoshiyasu; Sasaki, Naoki; Nambo, Yasuo

    2016-01-01

    Autopsy imaging (Ai), postmortem imaging before necropsy, is used in human forensic medicine. Ai was performed using computed tomography (CT) for a 1-month-old Thoroughbred foal cadaver found in a pasture. CT revealed pericardial effusion, collapse of the aorta, bleeding in the lung lobe, gas in the ventricles and liver parenchyma, and distension of the digestive tract. Rupture in the left auricle was confirmed by necropsy; however, it was not depicted on CT. Therefore, Ai and conventional necropsy are considered to complement each other. The cause of death was determined to be traumatic cardiac tamponade. In conclusion, Ai is an additional option for determining cause of death.

  18. Autopsy imaging for cardiac tamponade in a Thoroughbred foal

    PubMed Central

    YAMADA, Kazutaka; SATO, Fumio; HORIUCHI, Noriyuki; HIGUCHI, Tohru; KOBAYASHI, Yoshiyasu; SASAKI, Naoki; NAMBO, Yasuo

    2016-01-01

    ABSTRACT Autopsy imaging (Ai), postmortem imaging before necropsy, is used in human forensic medicine. Ai was performed using computed tomography (CT) for a 1-month-old Thoroughbred foal cadaver found in a pasture. CT revealed pericardial effusion, collapse of the aorta, bleeding in the lung lobe, gas in the ventricles and liver parenchyma, and distension of the digestive tract. Rupture in the left auricle was confirmed by necropsy; however, it was not depicted on CT. Therefore, Ai and conventional necropsy are considered to complement each other. The cause of death was determined to be traumatic cardiac tamponade. In conclusion, Ai is an additional option for determining cause of death. PMID:27703406

  19. Cardiac Magnetic Resonance for Evaluating Catheter Related FDG Avidity

    PubMed Central

    Gage, Kenneth L.; Berman, Claudia G.; Montilla-Soler, Jaime L.

    2016-01-01

    A 53-year-old female with a history of metastatic left arm melanoma presented for F(18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) which showed a moderately FDG avid focus at her port catheter tip near the cavoatrial junction. Although catheter tip related FDG avidity has previously been suggested to be bland thrombus or infection, melanoma can metastasize to unusual locations including the superior vena cava. In addition, the patient had an elevated risk of anticoagulation due to a history of hemorrhagic brain metastases. Therefore, confirmatory cardiac magnetic resonance (CMR) was obtained and findings were consistent with bland catheter-related thrombus. PMID:27867676

  20. A concealed atriopleural fistula resulting from a cardiac stab wound.

    PubMed

    Arnáiz-García, María Elena; Arnáiz, Javier; Pontón, Alejandro; Pulitani, Ivana; González-Santos, Jose María; Arévalo-Abascal, Adolfo; Bueno-Codoñer, María E; Arnáiz-García, Ana María

    2014-09-01

    A young male presented with a right parasternal stab wound. The chest radiography was normal and transthoracic echocardiography ruled out pericardial tamponade. He remained hemodynamically stable until three hours later when signs of progressive anemia were observed. Chest computed tomography showed massive right-sided hemothorax. The patient underwent surgery, which revealed an active bleeding atriopleural fistula connecting the right atrium and draining into the right pleura resulting from the negative pressure generated during respiration. This mechanism prevented cardiac tamponade and maintained initial hemodynamically stability.

  1. Recurrent Cardiac Tamponade: An Unusual Presentation of Intrahepatic Cholangiocarcinoma

    PubMed Central

    Corral, Juan E.; Arosemena, Leopoldo; Garcia-Buitrago, Monica T.; Madrazo, Beatrice; Martin, Paul

    2016-01-01

    A 48-year-old Egyptian woman presented with 8 months of sharp right upper chest pain and weight loss. She was discovered to have an enlarged cardiac silhouette on chest x-ray, and an echocardiogram revealed a large pericardial effusion with diastolic right atrial collapse. Pericardial window was done, and epithelial membrane antigen-positive neoplastic cells were identified in the pericardial fluid. Computed tomography showed a 6-cm hypermetabolic lesion on the liver segment IV, confirmed on biopsy to be a moderately differentiated adenocarcinoma consistent with intrahepatic cholangiocarcinoma. PMID:27144206

  2. Video-assisted thoracoscopic enucleation after congenital cardiac surgery

    PubMed Central

    Maeda, Hideyuki; Kanzaki, Masato; Isaka, Tamami; Onuki, Takamasa

    2015-01-01

    A 26-year-old man underwent arterial switch surgery for transposition of the great arteries in infancy. During a routine evaluation, a nodule was detected in the left lower lobe on chest computed tomography. The tumor had enlarged at follow-up and he underwent surgical resection. Because of past cardiac surgery, the pericardium was defective; therefore, the heart was exposed to the pleural cavity and severe adhesions surrounding the left lung. We had to encircle the left main pulmonary artery to perform enucleation safely. The tumor was diagnosed as a pulmonary sclerosing hemangioma using permanent pathology results. PMID:26385193

  3. Cardiac imaging: does radiation matter?

    PubMed Central

    Einstein, Andrew J.; Knuuti, Juhani

    2012-01-01

    The use of ionizing radiation in cardiovascular imaging has generated considerable discussion. Radiation should not be considered in isolation, but rather in the context of a careful examination of the benefits, risks, and costs of cardiovascular imaging. Such consideration requires an understanding of some fundamental aspects of the biology, physics, epidemiology, and terminology germane to radiation, as well as principles of radiological protection. This paper offers a concise, contemporary perspective on these areas by addressing pertinent questions relating to radiation and its application to cardiac imaging. PMID:21828062

  4. CARDIAC OPERATIONS WITH EXTRACORPOREAL CIRCULATION

    PubMed Central

    Kay, Jerome Harold; Anderson, Robert M.; Lewis, Reuben R.; Meihaus, John; Magidson, Oscar; Snyder, Edward N.; Bennett, Louis C.; Bernstein, Sol; Amsden, Neal

    1959-01-01

    In a series of 50 patients for whom a heart-lung machine was used for periods as long as 70 minutes during operations to correct structural defects of the heart, there were no deaths attributable to the machine. Seven patients died. Two of them had high pressure ventricular septal defects with bidirectional shunts; a third patient with the same lesion recovered after repair. One patient died of cardiac tamponade when a large blood clot formed about the entire heart in a loosely closed pericardial sac. Others died of various causes. The development of subacute bacterial endocarditis in one patient led to a change in sterilization of apparatus. PMID:13662856

  5. Cardiac Resynchronization Therapy in Women.

    PubMed

    Costanzo, Maria Rosa

    2017-01-01

    The benefits of cardiac resynchronization therapy (CRT) on the outcomes of patients with heart failure are unquestionable. Women are under-represented in all CRT studies. Most of the available data show that CRT produces a greater clinical benefit in women than men. In several studies, women have left bundle branch block more frequently than men. Women have a remarkably high (90%) CRT response over a wide range of QRS lengths (130-175 milliseconds). Use of a QRS duration of 150 milliseconds as the threshold for CRT prescription may deny a life-saving therapy to many women likely to benefit from CRT.

  6. Cardiac Resynchronization Therapy in Women.

    PubMed

    Costanzo, Maria Rosa

    2015-12-01

    The benefits of cardiac resynchronization therapy (CRT) on the outcomes of patients with heart failure are unquestionable. Women are under-represented in all CRT studies. Most of the available data show that CRT produces a greater clinical benefit in women than men. In several studies, women have left bundle branch block more frequently than men. Women have a remarkably high (90%) CRT response over a wide range of QRS lengths (130-175 milliseconds). Use of a QRS duration of 150 milliseconds as the threshold for CRT prescription may deny a life-saving therapy to many women likely to benefit from CRT.

  7. [Morgagni hernia causing cardiac tamponade].

    PubMed

    S Breinig; Paranon, S; Le Mandat, A; Galinier, P; Dulac, Y; Acar, P

    2010-10-01

    Morgagni hernia is a rare malformation (3% of diaphragmatic hernias). This hernia is usually asymptomatic in children. We report on a case revealed by an unusual complication. Severe cyanosis was due to right-to-left atrial shunt through the foramen ovale assessed by 2D echocardiography. Diagnosis of the Morgagni hernia was made with CT scan. The intrathoracic liver compressed the right chambers of the heart causing tamponade. Cardiac compression was reversed after surgery and replacement of the liver in the abdomen. Six months after the surgery, the infant was symptom-free with normal size right chambers of the heart.

  8. Echocardiographic assessment of cardiac disease

    NASA Technical Reports Server (NTRS)

    Popp, R. L.

    1976-01-01

    The physical principles and current applications of echocardiography in assessment of heart diseases are reviewed. Technical considerations and unresolved points relative to the use of echocardiography in various disease states are stressed. The discussion covers normal mitral valve motion, mitral stenosis, aortic regurgitation, atrial masses, mitral valve prolapse, and idiopathic hypertrophic subaortic stenosis. Other topics concern tricuspic valve abnormalities, aortic valve disease, pulmonic valve, pericardial effusion, intraventricular septal motion, and left ventricular function. The application of echocardiography to congenital heart disease diagnosis is discussed along with promising ultrasonic imaging systems. The utility of echocardiography in quantitative evaluation of cardiac disease is demonstrated.

  9. [Carney's Complex: familial cardiac myxoma].

    PubMed

    Guerra, Miguel S; Santos, Nelson; Neves, Fátima; Carlos Mota, João; Miranda, José António; Vouga, Luis

    2006-01-01

    The Carney Complex is a very rare autosomal dominant disease including multiple neoplasia syndrome. This syndrome was initially described in 1985 under the rubric "...the complex of myxomas, spotty pigmentation, and endocrine overactivity". We present a case report of an old woman with Carney Complex who had the characteristic features of facial hirsutism and acromegalic facies, a large pigmented swelling over the face and a cardiac myxoma arising from the left atrium. We emphasize the need for periodic echocardiographic screening of patients and family members.

  10. Computers and Computer Resources.

    ERIC Educational Resources Information Center

    Bitter, Gary

    1980-01-01

    This resource directory provides brief evaluative descriptions of six popular home computers and lists selected sources of educational software, computer books, and magazines. For a related article on microcomputers in the schools, see p53-58 of this journal issue. (SJL)

  11. Human atlas of the cardiac fiber architecture: study on a healthy population.

    PubMed

    Lombaert, Herve; Peyrat, Jean-Marc; Croisille, Pierre; Rapacchi, Stanislas; Fanton, Laurent; Cheriet, Farida; Clarysse, Patrick; Magnin, Isabelle; Delingette, Hervé; Ayache, Nicholas

    2012-07-01

    Cardiac fibers, as well as their local arrangement in laminar sheets, have a complex spatial variation of their orientation that has an important role in mechanical and electrical cardiac functions. In this paper, a statistical atlas of this cardiac fiber architecture is built for the first time using human datasets. This atlas provides an average description of the human cardiac fiber architecture along with its variability within the population. In this study, the population is composed of ten healthy human hearts whose cardiac fiber architecture is imaged ex vivo with DT-MRI acquisitions. The atlas construction is based on a computational framework that minimizes user interactions and combines most recent advances in image analysis: graph cuts for segmentation, symmetric log-domain diffeomorphic demons for registration, and log-Euclidean metric for diffusion tensor processing and statistical analysis. Results show that the helix angle of the average fiber orientation is highly correlated to the transmural depth and ranges from -41° on the epicardium to +66° on the endocardium. Moreover, we find that the fiber orientation dispersion across the population (±13°) is lower than for the laminar sheets (±31°) . This study, based on human hearts, extends previous studies on other mammals with concurring conclusions and provides a description of the cardiac fiber architecture more specific to human and better suited for clinical applications. Indeed, this statistical atlas can help to improve the computational models used for radio-frequency ablation, cardiac resynchronization therapy, surgical ventricular restoration, or diagnosis and followups of heart diseases due to fiber architecture anomalies.

  12. Cardiac dysfunctions following spinal cord injury

    PubMed Central

    Sandu, AM; Popescu, M; Iacobini, MA; Stoian, R; Neascu, C; Popa, F

    2009-01-01

    The aim of this article is to analyze cardiac dysfunctions occurring after spinal cord injury (SCI). Cardiac dysfunctions are common complications following SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. We reviewed epidemiology of cardiac disturbances after SCI, and neuroanatomy and pathophysiology of autonomic nervous system, sympathetic and parasympathetic. SCI causes disruption of descendent pathways from central control centers to spinal sympathetic neurons, originating into intermediolateral nuclei of T1–L2 spinal cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant cardiac dysfunction. Impairment of autonomic nervous control system, mostly in patients with cervical or high thoracic SCI, causes cardiac dysrrhythmias, especially bradycardia and, rarely, cardiac arrest, or tachyarrhytmias and hypotension. Specific complication dependent on the period of time after trauma like spinal shock and autonomic dysreflexia are also reviewed. Spinal shock occurs during the acute phase following SCI and is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe bradycardia and hypotension. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life–threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5–T6). Besides all this, additional cardiac complications, such as cardiac deconditioning and coronary heart disease may also occur. Proper prophylaxis, including nonpharmacologic and pharmacological strategies and cardiac rehabilitation diminish occurrence of the cardiac dysfunction following

  13. The effect of averaging cardiac Doppler spectrograms on the reduction of their amplitude variability.

    PubMed

    Cloutier, G; Allard, L; Guo, Z; Durand, L G

    1992-03-01

    The effect of averaging cardiac Doppler spectrograms on the reduction of their amplitude variability was investigated in 30 patients. Beat-to-beat variations in the amplitude of Doppler spectrograms were also analysed. The quantification of amplitude variability was based on the computation of the area under the absolute value of the derivative function of each spectrum composing mean spectrograms. Fast Fourier transform using a Hanning window was used to compute Doppler spectra. Results obtained over systolic and diastolic periods showed that the reduction of amplitude variability followed an exponentially decreasing curve characterised by the equation f (r) = 100 e-beta(r-1), where r is the number of cardiac cycles, beta the exponentially decreasing rate, and 100 the normalised variability for r = 1. In systole, the decreasing rate beta was 0.165, whereas in diastole it was 0.225. Reductions of the variability in systole for a number of cardiac cycles of 5, 10, 15, and 20 were 48, 77, 90 and 96 per cent, respectively. In diastole, reductions of the variability for the same numbers of cardiac cycles were 59, 87, 96 and 99 per cent, respectively. Based on these results, it can be concluded that no significant improvement in the reduction of amplitude variability may be obtained by averaging more than 20 cardiac cycles.

  14. Is High Temporal Resolution Achievable for Paediatric Cardiac Acquisitions during Several Heart Beats? Illustration with Cardiac Phase Contrast Cine-MRI

    PubMed Central

    Bonnemains, Laurent; Odille, Freddy; Meyer, Christophe; Hossu, Gabriella; Felblinger, Jacques; Vuissoz, Pierre-André

    2015-01-01

    Background During paediatric cardiac Cine-MRI, data acquired during cycles of different lengths must be combined. Most of the time, Feinstein’s model is used to project multiple cardiac cycles of variable lengths into a mean cycle. Objective To assess the effect of Feinstein projection on temporal resolution of Cine-MRI. Methods 1/The temporal errors during Feinstein’s projection were computed in 306 cardiac cycles fully characterized by tissue Doppler imaging with 6-phase analysis (from a population of 7 children and young adults). 2/The effects of these temporal errors on tissue velocities were assessed by simulating typical tissue phase mapping acquisitions and reconstructions. 3/Myocardial velocities curves, extracted from high-resolution phase-contrast cine images, were compared for the 6 volunteers with lowest and highest heart rate variability, within a population of 36 young adults. Results 1/The mean of temporal misalignments was 30 ms over the cardiac cycle but reached 60 ms during early diastole. 2/During phase contrast MRI simulation, early diastole velocity peaks were diminished by 6.1 cm/s leading to virtual disappearance of isovolumic relaxation peaks. 3/The smoothing and erasing of isovolumic relaxation peaks was confirmed on tissue phase mapping velocity curves, between subjects with low and high heart rate variability (p = 0.05). Conclusions Feinstein cardiac model creates temporal misalignments that impair high temporal resolution phase contrast cine imaging when beat-to-beat heart rate is changing. PMID:26599755

  15. Postoperative atrial fibrillation in non-cardiac and cardiac surgery: an overview.

    PubMed