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 miniaturized, newly developed, implantable rotary blood pump (the diagonal pump). In a series of six sheep, the pump was interposed in an atrial-aortic connection. Heart failure was induced by serial injection of glass beads into the left coronary artery, The assistance of the non-failing heart (with pump output up to 4.5 liter/min) did not change the total cardiac output or the blood pressure of the animal. The heart was significantly unloaded as demonstrated by a drop in first derivative of the left ventricular pressure (dP/dt) max (from 1645 to 1113 mmHg/s; P = 0.0003). Because of the specific interaction between heart function and rotary blood pump performance, the pump provided considerably more flow in the failing than in the non-failing heart. Cardiac output and perfusion pressures were restored to pre-assist values in the failing heart model. The heart-rotary blood pump interaction is an ideal substrate for long-term assistance. With this miniaturized rotary blood pump, hemodynamics in a severely failing heart can be restored. Atrial cannulation, which leaves the left ventricle untouched, provides similar results as apical cannulation in the failing heart. (C) 1998 The International Society for Cardiovascular Surgery. Published by Elsevier Science Ltd. All rights reserved.