Synchronously Counterpulsating Extracorporeal Life Support Enhances Myocardial Working Conditions Regardless of Systemic Perfusion Pressure

Objective: A new pulsatile extracorporeal life support (pECLS) system has entered the market. We wanted to investigate what potential advantages pECLS may have over current non-pulsatile systems (NPS). Our research was focused on the pump’s functional interaction with the left ventricle and the coronary circulation.

Methods: Extensive hemodynamic measurements were performed during asynchronous and synchronous pECLS in 10 calves. The two extremes regarding LV afterload, namely systolic arrival (SA) and diastolic arrival (DA) of the pump pulse were studied.

Results: SA was associated with increased oxygen consumption (+57%) and decreased diastolic coronary perfusion (-43%). DA increased left ventricular output (DA: 4.5+/-2.4l/min vs SA: 3.5+/-2.2l/min), LV ejection fraction (+10%), and ventricular efficiency (+17%). Mean aortic pressure and mean coronary flow were only marginally affected by pulse incidence. Systolic impairment was more pronounced with higher bypass flows. These results indicate that myocardial working conditions can be optimized by phasing pECLS ejection into cardiac diastole.

Conclusion: We conclude that during pECLS, myocardial working conditions can be improved by avoidance of systolic impairment. Synchronously counterpulsating pECLS could be a more economic and versatile alternative to NPS or NPS combined with intra-aortic balloon pumping. The potential benefits of synchronously counterpulsating pECLS over the current alternatives remain to be investigated.