Left ventricular (LV) distention is a known complication of venoarterial extracorporeal membrane oxygenation (VA-ECMO) due to increased afterload stress.¹ The consequences of LV distension include elevated pulmonary venous pressures leading to pulmonary edema and increased wall stress reducing the likelihood of ventricular recovery. Moreover, the LV may not be able to eject a reasonable stroke volume (SV); blood stasis may result in catastrophic thrombus formation. This investigation examines a simple formula that characterizes the impact of VA-ECMO on the LV as a function of ejection fraction (EF) and the changes in arterial pressure and SV.