OBJECTIVE To echocardiographically evaluate the effects of passive containment surgery using the CorCap Cardiac Support Device in heart failure patients with dilated cardiomyopathy. METHODS Twelve patients with dilated cardiomyopathy subjected to cardiac surgery received the Cardiac Support Device. Patients with ischemic cardiomyopathy (n=5) underwent coronary artery bypass surgery receiving 1-3 bypass grafts. In the idiopathic cardiomyopathy group (n=7), mitral valve annuloplasty was performed in five patients while two patients received the Cardiac Support Device only. RESULTS Following surgery there was a gradual, sustained improvement in cardiac dimensions (decreased left ventricular end-diastolic diameter and left ventricular end-systolic diameter) combined with an increase in functional status (6-min walk and NYHA class). Concomitantly there was a marked decrease in right ventricular function (decrease in tricuspid annular systolic and diastolic velocities) while the left ventricular function (mitral annular systolic and diastolic velocities) and output (ejection fraction, stroke volume) remained unchanged. CONCLUSIONS Addition of the Cardiac Support Device to conventional cardiac surgery improves patient status and decreases left ventricular size in heart failure patients with dilated cardiomyopathy. The positive effect on left ventricular dimensions is not accompanied by any improvement in cardiac output but rather right ventricular dysfunction, although the functional significance of this is unclear.