Experimental results and future prospects for a nonpulsatile cardiac prosthesis

Abstract

Abstract Replacing the heart function by means of a nonpulsatile blood pump is a great challenge to nature, which evolved pulsatile blood circulation. Some years ago, we hypothesized that mammalian physiology was capable of adapting to chronic nonpulsatile blood flow and maintaining normal organ function. The methodology of complete circulatory replacement with nonpulsatile flow has been established in awake calf experiments in our institution. To date, 5 animals have lived with nonpulsatile blood perfusion with near normal physiology for up to 3 months. Our studies on nonpulsatile biventricular animals have shown that immediately following surgery there is an adaptation phase which lasts approximately 7 to 10 days. This phase is characterized by increased total systemic vascular resistance (SVR), which appears to correlate with an increase in the circulating catecholamines. After this phase, these animals showed normal values of SVR, renal, biochemical, and endocrine function. Our data show that nonpulsatile blood flow is not a limiting factor to maintain mammalian life .