Comparison of right ventricular and biventricular circulatory support in a porcine model of right heart failure.
The effects of right ventricular (RVAD) and biventricular assist devices (BVAD) in an acute porcine model of right heart ischemic failure produced by occluding the right coronary artery for 2 min (RCAO) were compared. Right and left ventricular pressures were measured with Millar transducers and respective septal-to-free wall dimensions (RVSFWD, LVSFWD) with ultrasonic crystals. RCAO alone resulted in significant right heart failure, marked by a 36 +/- 5% reduction in cardiac output (pulmonary artery flow) and a 54 +/- 16% reduction in RV stroke work. Isolated RVAD significantly improved the hemodynamic conditions by restoring pulmonary blood flow and left heart filling to control levels. RVAD also resulted in reduced RVSFWD to control levels and increased LVSFWD via a rightward septal shift due to right heart unloading. Biventricular support resulted in the same hemodynamic improvement, but estimated LV peak systolic wall stress was reduced by 65 +/- 15% compared with control, due to concomitant LV unloading and reductions in LVSFWD. Therefore, either right or biventricular devices are effective in treating RV failure. The advantage of biventricular support is that the left ventricle is also unloaded, thus allowing improved circulatory support with minimal LV wall stress.
Farrar
D J
DJ
Department of Cardiovascular Surgery, Pacific Presbyterian Medical Center, San Francisco, California 94120.
Chow
E
E
Wood
J
J
Hill
J D
JD
D000818:Animals; D006333:Heart Failure / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D008955:Models, Cardiovascular; D013552:Swine; D016276:Ventricular Function / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology