MINIATURIZED IMPLANTABLE ROTARY BLOOD PUMP IN ATRIAL-AORTIC POSITION SUPPORTS AND UNLOADS THE FAILING HEART

The purpose of this study was to test the pump performance of a miniat urized, newly developed, implantable rotary blood pump (the diagonal p ump). In a series of six sheep, the pump was interposed in an atrial-a ortic connection. Heart failure was induced by serial injection of gla ss beads into the left coronary artery, The assistance of the non-fail ing heart (with pump output up to 4.5 liter/min) did not change the to tal cardiac output or the blood pressure of the animal. The heart was significantly unloaded as demonstrated by a drop in first derivative o f the left ventricular pressure (dP/dt) max (from 1645 to 1113 mmHg/s; P = 0.0003). Because of the specific interaction between heart functi on and rotary blood pump performance, the pump provided considerably m ore flow in the failing than in the non-failing heart. Cardiac output and perfusion pressures were restored to pre-assist values in the fail ing heart model. The heart-rotary blood pump interaction is an ideal s ubstrate for long-term assistance. With this miniaturized rotary blood pump, hemodynamics in a severely failing heart can be restored. Atria l cannulation, which leaves the left ventricle untouched, provides sim ilar results as apical cannulation in the failing heart. (C) 1998 The International Society for Cardiovascular Surgery. Published by Elsevie r Science Ltd. All rights reserved.