Therapy and Prevention Congenital Heart Disease

Despite increasing use of Fontan or modified Fontan repairs, the comparative hemodynamic efficacy of different types of connections are unresolved. Accordingly, we undertook a prospective study designed to determine postoperative flow patterns after Fontan's operation. Seven subjects had tricuspid atresia and eight had single ventricle. Ages ranged from 5 to 38 years (mean 16.4). Ten subjects had nonvalved right atrial-to-pulmonary arterial connection, and four had nonvalved right atrial-to-right ventricular communication. A valved conduit established continuity between the right atrium and right ventricle in one subject. Doppler flow profiles were recorded in the pulmonary artery and in the superior and inferior venae cavae of each. A reference electrocardiogram was used for timing purposes. In 14 patients, forward flow in the pulmonary artery was biphasic. Flow began at the end of the T wave (early ventricular diastole), peaked at or before the P wave (atrial systole), and returned to baseline by the peak of the R wave. Forward flow recommenced at the peak of the R wave (ventricular systole) and returned to baseline at the end of the T wave. Flow in the superior vena cava varied, and could not be recorded in three subjects. Between the end of the P wave and peak of the R wave (atrial systole) flow was reversed in eight, absent in three, and forward in one patient. Forward flow occurred between the peak of the R wave and the end of the T wave and was either continuous or biphasic. Fourteen patients had adequate studies of inferior vena cava flow; reversed flow during atrial systole occurred in 10 subjects. Three had no flow during atrial systole and one subject had forward flow. The patterns of forward flow were similar to those observed in the superior vena cava. These data indicate that pulmonary arterial and caval flow patterns after Fontan's operation for tricuspid atresia or single ventricle are not dependent on the preoperative anomaly or type of communication used at surgery. Circulation 70, No. 5, 898-902, 1984. HEMODYNAMIC RESULTS after Fontan's procedure are believed to depend on the basic anomaly, the preoperative physiology, and the type of communication used at surgery. Most investigators advocate, whenever possible, the inclusion of a subpulmonary ventricular chamber in the repair. ' The use of valved conduits is presently controversial. Since the longterm outcome in patients receiving valved homografts is problematic, the insertion of these valves is generally avoided in the atriopulmonary anastamosis. 3 5 However, others report that valved conduits between the From the Departments of Pediatrics and Medicine, Divisions of Cardiology, University of California, Los Angeles. Address for correspondence: Thomas G. DiSessa. M.D., Division of Pediatric Cardiology, Departament of Pediatrics. UCLA Medical Center, Los Angeles, CA 90024. Received July 12, 1984; accepted Aug. 16. 1984. 898 right atrium and pulmonary artery or subpulmonary chamber are hemodynamically desirable., 6-10 Recently Nakazawa et al.," using an intracardiac velocity probe, demonstrated that maximal pulmonary flow occurred after atrial systole. It has also been stressed that pulmonary arterial flow patterns are influenced by inherent conduit resistance or obstruction. 12 Despite increasing applications of Fontan or modified Fontan repairs, the comparative hemodynamic efficacy of a right atrial-to-pulmonary arterial or right atrial-to-subpulmonic chamber anatomosis, or valved vs nonvalved connections, remains unknown. In addition, the role of these various repairs in subjects with anatomically different anomalies is in question. Accordingly, we designed a prospective pulsed Doppler investigation of subjects with either tricuspid atresia or CIRCULATION by gest on A ril 4, 2017 http://ciajournals.org/ D ow nladed from THERAPY AND PREVENTION-CONGENITAL HEART DISEASE