Reversible myocardial depression in survivors of cardiac arrest.

Three patients under 40-years old who survived cardiac arrest due to ventricular fibrillation were originally diagnosed as having idiopathic dilated cardiomyopathy. Shortly after cardiac arrest, assessment of myocardial function revealed a globally dilated left ventricle in each patient with an estimated ejection fraction between 20% and 30%. Serial assessment of myocardial function, however, showed either normal or near-normal function by 2 weeks postevent. These findings suggest that myocardial stunning due to hypoperfusion during ventricular fibrillation or the effects of transthoracic shocks may result in profound, reversible myocardial depression in survivors of cardiac arrest. Serial evaluation of left ventricular function may be of value in selected survivors of cardiac arrest in order to evaluate time-dependent resolution of myocardial dysfunction and may prevent misdiagnosis of idiopathic dilated cardiomyopathy.