IT is now generally accepted that blood flow is unaffected by depulsation,1-4 but there is considerable evidence that tissue function is impaired by nonpulsatile perfusion.5-7 Although there have been many interesting studies of the effects of depulsation on renal function, their results have been contradictory. Further, because extracorporeal pumping mechanisms have been used to achieve nonpulsatile flow and because of the possible limitations imposed by the preparations used, their applicability to the intact organism is uncertain.
In our laboratory, we have designed a depulsation model that uses a passive, electronically controlled, pulse-shaping device installed in series with the aorta. The device is energized by the heart, rather than by an extracorporeal pump, and allows the autoregulatory mechanisms to retain their integrity.
In studies4 of the systemic-physiologic effects of total and regional depulsation, we found a significant rise of 9.6% in mean aortic pressure and peripheral resistance when the