Impact of Valves in a Biomechanical Heart Model Assisting Failing Hearts

Abstract

Experimental valveless muscular blood pumps (biomechanical hearts) in goats can pump more than 1 L·min⁻¹, but due to a high pendulum volume, no significant flow contribution to the circulation is gained. Thus valved and valveless biomechanical hearts were compared for efficacy. Heart failure was induced in 5 adult Bore goats by repeated intracoronary embolization. A valved and balloon-equipped pumping chamber was integrated into the descending aorta, simulating standard biomechanical circulatory support. The valveless biomechanical heart supported a failing heart with a baseline cardiac output of 2,670 ± 710 mL·min⁻¹ by contributing additional flow of 113 ± 37 mL·min⁻¹. The biomechanical heart model incorporating an outlet valve offered an additional 304 ± 126 mL·min⁻¹, and the use of 2 valves significantly enhanced pulmonary blood flow by 1,235 ± 526 mL·min⁻¹. The use of 2 valves in biomechanical hearts seems to be essential to achieve adequate circulatory support. Double-valved biomechanical hearts driven by an appropriate skeletal muscle ventricle may contribute to the therapy of heart failure.