Electrocardiogram-synchronized pulsatility for ECMO
Despite substantial advances in current extracorporeal life support (ECLS) technology, mechanical complications within the circuit and complications involving vital organs account for most of the mortality in patients undergoing ECLS for cardiac complications. An ideal ECLS system should generate pulsatile flow synchronized to the patient’s innate pulse to maximize hemodynamic energy transmission to the patient. In vitro experiments showed that the electrocardiogram (ECG)-synchronized ECLS system can generate pulsatile flow and surplus hemodynamic energy effectively at low flow rates and high rotational speeds for simulated healthy and damaged heart conditions. However, the system generates significantly lower surplus hemodynamic energy when the flow rate is closer to full flow support for adults while maintaining higher pump speeds raise hemolysis concerns. In vivo studies revealed that ECG-synchronized pulsatility can lead to significant improvements in renal function, coronary diastolic blood flow, and hemodynamic stability in adult swine models over continuous flow ECLS systems. In vitro studies for off-label use in neonatal and pediatric ECLS systems demonstrated it can also automatically adjust the pulsatile assist ratio to accommodate for higher heart rates, though at the expense of hemodynamic energy loss. More translational research of these novel systems is required to routinely use them in pediatric and adult clinical settings.
