Abstract 17953: A Novel Biodegradable Cardiac Support Device for Treating Ischemic Cardiomyopathy in Canine Heart

Introduction: The non-biodegradable material-made “Corecap” type cardiac support device reportedly reduces diastolic wall stress and consequently improves systolic cardiac function. However, the efficacy was inconsistent in the clinical studies possibly due to device-related impairment of diastolic cardiac function. We herein hypothesized that use of biodegradable material for the cardiac support device may contribute to improvement in both systolic and diastolic function of the failing heart. Methods: Polyglycolic acid and Polyethyleneterephtalate were used to prepare biodegradable (n=6) and non-biodegradable (n=5) cardiac support device, respectively. Both cardiac support devices were structurally designed to cover the entire ventricles of the 12-month-aged Beagle canine heart that was subjected to anterior coronary artery ligation at 1 week prior to the implantation. Sham operation was performed in coronary artery-ligated canines for control (n=7). Results: At 12 weeks after coronary artery ligation, the biodegradable group showed a greater recovery of ejection fraction than the non-biodegradable and the control group (39 ± 4% vs. 31 ± 4% vs. 30± 3, respectively, P <0.05), assessed by multi-detector computed tomography. Echocardiographically, diastolic function evaluated by Doppler-derived mitral deceleration time at 12 weeks was significantly greater in the biodegradable group (108 ± 18 msec) than the non-biogradable group (70 ± 13 msec, P<0.05). Thickness of connective tissues around the epicardium was significantly less in the biodegradable groups than the non-biodegradable group at 12 weeks. Histologically, fibrosis in the infarct area was significantly less in the treatment groups than the control group. Conclusions: Implantation of cardiac support device made of biodegradable material was effective in improvement of both systolic and diastolic function of the canine infarct heart for 12 weeks, compared with that of non-biodegradable material, warranting clinical studies using biodegradable cardiac support device.

Download Full-text

Abstract 402: Vitamin C Deficiency Impairs Cardiac Function and Post-infarction Survival in the Mouse

Circulation Research ◽

10.1161/res.121.suppl_1.402 ◽

2017 ◽

Vol 121 (suppl_1) ◽

Author(s):

Adolfo G Mauro ◽

Donatas Kraskauskas ◽

Bassem M Mohammed ◽

Bernard J Fisher ◽

Eleonora Mezzaroma ◽

...

Keyword(s):

Vitamin C ◽

Cardiac Function ◽

Diastolic Function ◽

Left Ventricular ◽

Coronary Artery Ligation ◽

Artery Ligation ◽

Additional Group ◽

Gulonolactone Oxidase ◽

Low Levels ◽

Systolic And Diastolic Function

Introduction: L-gulonolactone oxidase (Gulo) is the rate limiting enzyme for Vitamin C (VitC) biosynthesis. Humans rely on dietary VitC for collagen synthesis, extracellular matrix formation, and tissue regeneration. VitC deficiency is an unrecognized condition and its role in cardiac homeostasis and post-acute myocardial infarction (AMI) remodeling is unknown. Hypothesis: Low levels of VitC impair cardiac function and tissue repair following AMI. Methods: Adult male Gulo -/- knockout mice (C57BL6 background, N=8) and control C57BL (N=8), which are able to synthesize VitC were used. VitC deficiency was maintained supplying low levels of VitC (30mg/l) to Gulo -/- mice in drinking water. Mice underwent M-mode and Doppler echocardiography to measure left ventricular (LV) diameters and wall thicknesses, fractional shortening (FS), E and A waves, E/A ratio, isovolumetric relaxation time (IRT) and myocardial performance index (MPI). Experimental AMI was induced by coronary artery ligation for 7 days. An additional group of Gulo -/- were mice supplemented with physiological levels of VitC (330 mg/l) and underwent AMI. Results: VitC deficient Gulo -/- mice exhibited significantly reduced LV wall thicknesses, reduced FS, and impaired diastolic function, measured as significantly reduced E/A ratio and longer IRT (Panel A, B & C). Following AMI, 100% (8/8) of deficient Gulo -/- mice died within 5 days. Supplementation with physiological levels of VitC significantly improved survival after AMI (Panel D). Conclusion: VitC deficiency impairs systolic and diastolic function. Moreover, VitC is critical for the post-AMI survival.

Download Full-text

Survival Following Acute Coronary Artery Ligation Subsequent to Irradiation of Canine Heart.

Experimental Biology and Medicine ◽

10.3181/00379727-100-24501 ◽

1959 ◽

Vol 100 (1) ◽

pp. 1-3 ◽

Cited By ~ 1

Author(s):

E. Senderoff ◽

D. J. Kavee ◽

R. J. R. Johnson ◽

I. D. Baronofsky

Keyword(s):

Coronary Artery ◽

Coronary Artery Ligation ◽

Canine Heart ◽

Artery Ligation

Download Full-text

Zatebradine Slows Ectopic Ventricular Rhythms in Canine Heart 24 Hours After Coronary Artery Ligation

Journal of Cardiovascular Pharmacology ◽

10.1097/00005344-199705000-00015 ◽

1997 ◽

Vol 29 (5) ◽

pp. 662-669 ◽

Cited By ~ 1

Author(s):

Steven M. Lasker ◽

Daying Han ◽

Richard Paul Kline

Keyword(s):

Coronary Artery ◽

Coronary Artery Ligation ◽

Canine Heart ◽

Artery Ligation

Download Full-text

Abstract 48: Differentiation of Moderate and Severe Ischemic Heart Failure by Invasive and Non-invasive Assessments of Diastolic Function in a Rat Model of Chronic Heart Failure

Circulation Research ◽

10.1161/res.119.suppl_1.48 ◽

2016 ◽

Vol 119 (suppl_1) ◽

Author(s):

Saffie Mohran ◽

Jordan Lancaster ◽

Pablo Sanchez ◽

Steven Goldman ◽

Elizabeth Juneman

Keyword(s):

Heart Failure ◽

Coronary Artery ◽

Diastolic Function ◽

Left Coronary Artery ◽

Diastolic Pressure ◽

Left Ventricular ◽

Dead Volume ◽

Coronary Artery Ligation ◽

Artery Ligation ◽

Hemodynamic Measurements

Background: This work is designed to determine if specific left ventricle (LV) pressure-volume relations, hemodynamic, and echo derived parameters of diastolic function are able to separate severe from moderate CHF in rats with left coronary artery occlusion. Hypothesis: Echocardiographic indices of diastolic function, end-diastolic pressure (EDP), dead volume, stiffness constants (k), and pressure volume relations predict the severity of CHF in infarcted rats. Methods: Male Sprague Dawley rats (N=14) were randomized to undergo left coronary artery ligation or sham operation. Echocardiography was performed at 3 and 6 weeks post coronary ligation. The rats were categorized into moderate or severe CHF according to their LVEDP at 6 weeks post ligation. Invasive hemodynamic measurements with solid state micro manometer pressure catheters as well as diastolic pressure-volume relation values were obtained at the 6 week end point. Results: Moderate and severe CHF rats had significantly (P<0.05) elevated left ventricular (LV) end-diastolic pressure (LV EDPs), prolonged time constants of LV relaxation (tau), and decreased peak development pressures. When moderate versus severe CHF rats were separated based on LV EDP, early diastolic anterior wall radial relaxation velocity as well as e’, and E/e’ had strong correlations with invasive hemodynamic measurements of diastolic functions. There was a trend towards decreased compliance as measured by stiffness constants in severe heart failure group. Differences (P<0.05) in dead volume, mean arterial pressure (MAP), tau, and ejection fraction (EF) were also displayed. End diastolic pressure-volume analyses illustrated significant differences in plot positioning and curvature. Conclusion: While it is possible to separate rats with moderate and severe CHF in the rat coronary artery ligation model, the separation is not simply based on a specific EF value. This work may be useful in deciding whether there is a differential effect of new treatments for severe versus moderate CHF.

Download Full-text