Impact of Venoarterial Extracorporeal Membrane Oxygenation on Hemodynamics and Cardiac Mechanics: Insights From Pressure-Volume Loop Analysis.

Abstract

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) serves as a critical mechanical circulatory support modality, sustaining systemic circulation in cases of severe cardiac failure or cardiac arrest. While VA-ECMO improves hemodynamics, it markedly increases left ventricular (LV) afterload, contributing to pulmonary congestion and thrombus formation. This review highlights the hemodynamic and mechanical effects of VA-ECMO, employing the pressure-volume (PV) loop and the generalized circulatory equilibrium model. The PV loop framework clarifies how VA-ECMO elevates afterload, potentially reducing stroke volume and the cardiac output curve when LV contractility is severely impaired. Similarly, the generalized circulatory equilibrium concept illustrates how VA-ECMO shifts the circulatory equilibrium point in both ventricles. These models establish a mechanistic foundation for strategies combining VA-ECMO with other devices, such as an intra-aortic balloon pump, Impella, or central VA-ECMO equipped with LV venting. Based on these frameworks, appropriate patient selection, effective device management, and integration with LV unloading devices may enhance survival in patients requiring VA-ECMO.