In vitro evaluation of the influence of pulsatile intraventricular pumping on ventricular pressure patterns.
The Pulsatile catheter (PUCA) pump consists of a single port membrane pump connected to an indwelling valved catheter. This so-called transarterial blood pump was originally designed to be introduced through a superficial artery into the left ventricular cavity to pump blood from the left ventricle into the ascending aorta. By introducing the catheter directly into the thoracic aorta or the pulmonary artery, the possibility is created of applying large-diameter catheter PUCA pumps as left, right, or biventricular assist devices (LVAD, RVAD, or BIVAD) without damaging any of the structures of the heart. The pump performance of an 8 mm PUCA pump prototype (internal diameter catheter, 8 mm; catheter length, 40 cm; stroke volume, 80 ml) was studied in a mock circulation to investigate the influence of pulsatile intraventricular pumping on ventricular pressure patterns. The pumping mode of the PUCA pump was changed from approximately 1:1 ([n + 1]:n) to 1:2 ([1/2n + 1]:n) and 1:3 ([1/3n + 1]:n) in relation to the frequency of a ventricle-simulating membrane pump. Apart from the pumping mode, timing of the PUCA pump driving system (ejection phase) seems to be crucial in obtaining optimal unloading of the ventricle.