NUMERICAL-SIMULATION OF NONPULSATILE LEFT-VENTRICULAR BYPASS

A computer simulation was carried out to investigate the influence of nonpulsatile left ventricular assistance on hemodynamics. A simulation circuit was constructed to represent the circulatory system. A source of current was added to denote the nonpulsatile blood pump. The left and right ventricles were replaced by variable compliances. Left heart failure was simulated by decreasing the amount of compliance change o f the left ventricle, We introduced a pulsatility indicator (PI) to cl arify the pulsatility characteristics in the hemodynamics; this PI was defined as the ratio of the pulse pressure (PP) to the mean aortic pr essure (AoP). When nonpulsatile bypass flow increased, the mean AoP, t ension time index (TTI), and diastolic pressure time index (DPTI) incr eased, and cardiac output, PP, and PI decreased. When assisted flow in creased with the constant total flow rate, the mean AoP and DPTI chang ed little; the PP, TTI, and PI decreased, and the endocardial viabilit y rate increased. The PI would be helpful in evaluating the effect of pulsatility.