Sustained heart failure induced by repeated microsphere injections for left ventricular assist device testing

A subacute to chronic heart failure model was established to test left ventricular assist device (LVAD) systems. Five calves were anesthetized and instrumented. Heart failure was induced by daily injection of polystyrene microspheres (37-70 microns) into a left coronary catheter. The last three animals had an atrio-aortic pulsatile LVAD implanted. Cardiac output (CO) decreased from 12 to 5.5 L/min, and SV from 120 to 60 ml, whereas left atrial pressure (LAP) increased from 12 to 25 mmHg within 10 to 20 days in the two animals without LVAD support. Both animals stopped eating and drinking. The LVAD experiments were terminated after 5, 10, and 11 days. Cardiac function was determined during daily pump-off tests. After repeated microsphere injections, LAP increased to 30 and 50 mmHg, and CO decreased to 4 and 6 L/min without pump support. Daily stepwise microsphere injections induce a sclerotic cardiomyopathy in a safe and reliable manner.