Left ventricular distention (LVD) during venoarterial extracorporeal membrane oxygenation (VA-ECMO) support is increasingly recognized but seldom reported in the literature. The current study defined LVD as not present (LVD−); subclinical (LVD+, evidence of pulmonary edema on chest radiograph AND pulmonary artery diastolic blood pressure greater than 25 mm Hg within the first 2 hours of intensive care unit admission); or clinical (LVD++, need for decompression of the left ventricle immediately following VA-ECMO initiation). Among 226 VA-ECMO device runs, 121 had sufficient data to define LVD retrospectively. Nine patients (7%) developed LVD++ requiring immediate decompression, and 27 patients (22%) met the definition of LVD+. Survival to discharge was similar among groups (LVD++: 44%, LVD+: 41%, LVD−: 44%). However, myocardial recovery appeared inversely related to the degree of LVD (LVD++: 11%, LVD+: 26%, LVD−: 40%). When death or transition to device was considered as a composite outcome, event-free survival was diminished in LVD++ and LVD+ patients compared with LVD−. Multivariable analysis identified cannulation of VA-ECMO during extracorporeal cardiopulmonary resuscitation (ECPR) as a risk factor for decompression (odds ratio [OR]: 3.64, confidence interval [CI]: 1.21–10.98; p = 0.022). Using a novel definition of LVD, the severity LVD was inversely related to the likelihood of myocardial recovery. Survival did not differ between groups. Extracorporeal cardiopulmonary resuscitation was associated with need for mechanical intervention.