Hemodynamic studies after total correction of tetralogy of Fallot

Twenty patients were studied by right heart catheterization 5 to 23 months after complete surgical correction of tetralogy of Fallot. The ventricular septal defects had been closed with a polyvinyl sponge and a Teflon prosthesis had been used to widen the right ventricular outflow tract in each case. Residual systolic gradients between the right ventricle and pulmonary artery were small. Fifteen patients had gradients of 15 mm. or less, and the highest found was 34 mm. Arterial oxygen saturation was normal at rest or with exercise, or both, in nearly all cases. Two patients had definite evidence of a persistent ventricular septal defect with a left-to-right shunt. Pulmonic regurgitation was present in 13 patients. Despite elevated right ventricular end diastolic and right atrial pressures in some patients, clinical evidence of heart failure was absent in all at the time of catheterization. A comparison was made of the right ventricular and pulmonary arterial pressure measurements obtained in the operating room upon completion of the cardiac repair with those made at catheterization. It was found that pressure measurements at surgery give a reliable indication of the effectiveness of relief of the right ventricular outflow stenosis. The operation employed in these patients has relieved the physiologic abnormalities of tetralogy of Fallot. Pulmonic regurgitation is present in many of the patients but is tolerated well at present. The long-term effects of this new abnormality will become clear only after extended observation.