Treadmill Exercise in Calves Implanted with the AbioCor Replacement Heart

Abstract

The aim of this study was to evaluate the function of the AbioCor artificial heart implanted in calves that underwent treadmill exercise testing and to investigate the cardiovascular and metabolic responses during exercise. Six calves were implanted with the AbioCor. One week after surgery, exercise training was undertaken and animals were put on a treadmill at a speed of 0.5-1.0 mph, with the AbioCor operating at the maximum heart rate of 150 beats per minute. During exercise, the left and right atrial pressures were significantly increased (p < 0.05). Oxygen consumption was significantly elevated (p < 0.05). Lactate levels did not significantly increase (p > 0.05). The index of metabolic adequacy remained higher than 2.0, indicating that there was no substantial transition to anaerobic metabolism during exercise. There was an increased extraction of oxygen during exercise to meet the increased energy demands. Our study demonstrated that animals implanted with the AbioCor heart were able to maintain aerobic metabolism during low levels of exercise testing.

Effect of Parameter Variations on the Hemodynamic Response Under Rotary Blood Pump Assistance

“…Numerical models (4-7), in vitro mock circulatory experiments (8)(9)(10), in vivo animal studies (11)(12)(13), as well as human trials (14)(15)(16) have been widely used to study the interaction between the IRBPs and the cardiovascular system (CVS). McConnell et al (11) evaluated load-dependent ventricular function during left ventricular assist device (LVAD) support based on telemetered measurements of left ventricular (LV) pressure in six adult sheep.…”

“…McConnell et al (11) evaluated load-dependent ventricular function during left ventricular assist device (LVAD) support based on telemetered measurements of left ventricular (LV) pressure in six adult sheep. In another study, Chiang et al (12) investigated the cardiovascular and metabolic responses in calves implanted with an AbioCor artificial heart during treadmill exercise. To determine the optimal support level of an LVAD, Goldstein et al (13) measured the LV myocardial oxygen consumption as well as stroke work in an ovine model of microinfarction-induced CHF under different pump assistance levels.…”

“…Numerical models (4–7), in vitro mock circulatory experiments (8–10), in vivo animal studies (11–13), as well as human trials (14–16) have been widely used to study the interaction between the IRBPs and the cardiovascular system (CVS). McConnell et al.…”

“…In another study, Chiang et al. (12) investigated the cardiovascular and metabolic responses in calves implanted with an AbioCor artificial heart during treadmill exercise. To determine the optimal support level of an LVAD, Goldstein et al.…”