Reports of dysfunction of the systemic ventricle exist for patients with tetralogy of Fallot, ventricular septal defects and dextro transposition of the great arteries. This study utilizes combined cardiac catheterization and non-invasive techniques to evaluate longterm function of the systemic ventricle in patients having undergone total surgical repair of one of these congenital heart lesions. To evaluate function of the systemic ventricle, hemodynamic parameters will be measured at the time of left and right heart catheterizations at rest and during increasing afterload induced by infusion of the selective alpha pressor, methoxamine. Ventricular function will be evaluated by generating work-function curves relating ventricular end diastolic pressure to ventricular work. This relationship will be assessed and compared in study and control patients. In addition, echocardiographic indices of ventricular function and ventricular end systolic pressure dimension relationships will be assessed. A pilot study has been completed in repaired tetralogy of Fallot patients showing that despite satisfactory postoperative resting hemodynamics, left ventricular dysfunction can be unmasked by stress with an increased afterload. To determine whether the observed changes in ventricular function arise from alteration in diastolic pressure-volume relationships or from systolic dysfunction, simultaneously obtained ventricular pressure recordings and echocardiographically determined diastolic dimensions will be used to compare the end-diastolic dimension stroke work index relationship to the end-diastolic pressure stroke work index. By assessing the function of the systemic ventricle in congenital heart patients repaired at various ages, the hypothesis that cardiac function may be preserved by early surgical repair can be tested. Finally, a totally non-invasive method of assessing ventricular performances is proposed. If validated by cardiac catheterization correlation, this method will allow for repeated non-invasive longterm followup of the study patients.