title: Right ventricular function during left heart bypass.
abstract: Right heart failure may occur during mechanical support of the left ventricle (LV). Right ventricular (RV) functional changes were studied in eight dogs (26.9 +/- 1.4 kg) subjected to various degrees of left heart bypass (LHBP) with a roller pump. The venous return to the right atrium was controlled with a second pump. RV function was evaluated by peak RV developed pressure, its first derivative (dp/dt), and mean RA pressure measurements. Left atrial, LV, and aortic pressure and both roller pump flows were determined. Incremental increases in LHBP flow ratio ([LHBP flow x 100] divided by venous return flow) to 60%, 90%, and 100% were associated with decrements in RV dp/dt from the control of 212 +/- 17 torr/sec to 192 +/- 16, 178 +/- 16, and 168 +/- 13 torr/sec, respectively. Biventricular bypass or total cardiopulmonary bypass with extracorporeal membrane oxygenation seems to be indicated if LHBP flow ratio greater than 90% is required to maintain adequate body perfusion. Maximal LV decompression to obtain the greatest reduction of LV myocardial oxygen consumption may not be the ideal goal during LV mechanical assistance.
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001026:Coronary Artery Bypass / Q000379:methods*; D004285:Dogs; D008954:Models, Biological; D016276:Ventricular Function