Background Global left ventricular dysfunction after successful resuscitation is well documented and appears to be a major contributing factor in limiting long-term survival after initial recovery from out-of-hospital sudden cardiac death. Treatment of such postresuscitation myocardial dysfunction has not been examined previously. Methods and Results Systolic and diastolic parameters of left ventricular function were measured in 27 swine before and after successful resuscitation from prolonged ventricular fibrillation cardiac arrest. Dobutamine infusions (10 μg·kg −1 ·min −1 in 14 animals or 5 μg·kg −1 ·min −1 in 5 animals) begun 15 minutes after resuscitation were compared with controls receiving no treatment (8 animals). The marked deterioration in systolic and diastolic left ventricular function seen in the control group after resuscitation was ameliorated in the dobutamine-treated animals. Left ventricular ejection fraction fell from a prearrest 58±3% to 25±3% at 5 hours after resuscitation in the control group but remained unchanged in the dobutamine (10 μg·kg −1 ·min −1 ) group (52±1% prearrest and 55±3% at 5 hours after resuscitation). Measurement of the constant of isovolumic relaxation of the left ventricle (τ) demonstrated a similar benefit of the dobutamine infusion for overcoming postresuscitation diastolic dysfunction. The τ rose in the controls from 28±1 milliseconds (ms) prearrest to 41±3 ms at 5 hours after resuscitation whereas it remained constant in the dobutamine-treated animals (31±1 ms prearrest and 31±5 ms at 5 hours after resuscitation). Conclusions Dobutamine begun within 15 minutes of successful resuscitation can successfully overcome the global systolic and diastolic left ventricular dysfunction resulting from prolonged cardiac arrest and cardiopulmonary resuscitation.