The effect of left ventricular assist device (LVAD) on cardiac reserve in dogs

The effect of LVAD on the preservation of cardiac reserve against ischemic damage was studied using Sarnoff's ventricular function curve. An LVAD was implanted between the canine left atrium and the aorta. Left ventricular function was measured by changing the height of the reservoir connected to the left atrium. The left ventricular function curve (LVFC) was drawn by plotting left ventricular stroke work (LVSW) against left atrial pressure (LAP). The coronary artery was occluded under a pump-on (ON group) or pump-off (OFF group). After reperfusion, measurements were repeated and changes in the LVFC caused by ischemia were compared in both groups. The gradient of the LVFC was significantly reduced by ischemia (107 +/- 15 ml/beat----80 +/- 14, n = 13) but not in the ON group. LVSW under normal preload did not significantly change in either group. This suggests that the LVAD preserved cardiac reserve against ischemic damage.