Evaluation of the optimal driving mode during left ventricular assist with pulsatile catheter pump in calves

The pulsatile catheter (PUCA) pump, a left ventricular assist device, was tested during acute experiments in calves using asynchronous and ECG- synchronous assist modes. The aim of the study is to compare ECG-synchronous and asynchronous assist and to find the optimal driving mode for the PUCA pump with respect to left ventricular myocardial oxygen consumption (LV MVO₂), pump flow, and coronary flow. LV MVO₂ decreased significantly during the asynchronous (from 7.77 to 6.46 ml/min/100 g) as well as during the ECG- synchronous mode (from 8.88 to 7.84 ml/min/100 g). The pump flow was highest during the ECG-synchronous assist (2.94 L/min), followed by the asynchronous assist (2.79 L/min). The peak coronary flow depended strongly on pump ejection timing and showed the best flow patterns during the ECG-synchronous assist. We concluded that for PUCA pump support both asynchronous and ECG- synchronous assists significantly reduce LV MVO₂ and that the pump flow generated is enough to maintain the systemic circulation. However, we find the ECG-synchronous mode preferable because this mode optimizes coronary flow patterns at the same time.