RIGHT-VENTRICULAR DIASTOLIC FUNCTION IN CHILDREN WITH PULMONARY REGURGITATION AFTER REPAIR OF TETRALOGY OF FALLOT - VOLUMETRIC EVALUATION BY MAGNETIC-RESONANCE VELOCITY MAPPING

Objectives. We sought to assess right ventricular diastolic function i n young patients with corrected tetralogy of Fallot and pulmonary regu rgitation. Background. Pulmonary regurgitation is an important problem in repair of tetralogy of Fallot. Its effects on right ventricular di astolic function in children are unknown. Methods. Nineteen children w ith repair of tetralogy of Fallot (mean age [+/- SD] 12 +/- 3 years, m ean age at operation 1.5 +/- 1) and 12 healthy children were studied. Summation of magnetic resonance velocity mapping pulmonary and tricusp id volume how curves provided right ventricular time-volume curves. Ve ntricular size was assessed with tomographic magnetic resonance imagin g (R-IRI). Graded exercise testing was performed, Results. Systematic and random differences (mean +/- SD) of velocity mapping and Doppler t ricuspid time to peak velocities (peak E: 1 +/- 26 ms, r = 0.43; peak A: 2 +/- 11 ms, r = 0.76), E/A ratios (0.04 +/- 0.5, r = 0.63) and dur ation of pulmonary regurgitation (20 +/- 35 ms, r = 0.74) were satisfa ctory. In 6 patients (group I), late diastolic forward pulmonary arter y flow was absent; in 13 patients (group II), this flow contributed 1% to 14% to right ventricular stroke volume. Significant differences we re increased deceleration time (315 +/- 91 vs. 168 +/- 28 ms, p < 0.00 1), decreased filling fraction (44 +/- 11 vs. 55 +/- 16%, p = 0.02) an d increased peak early filling rate (378 +/- 124 vs. 286 +/- 112 ml/s, p = 0.018) between control subjects and group I, and increased decele ration time (230 +/- 40, p = 0.03) between control subjects and group II. Pulmonary regurgitation, ventricular size and ejection fraction di d not differ significantly between patient groups. Exercise function w as diminished with restrictive right ventricular physiology (p < 0.001 , group II vs. control subjects). Conclusions. Impaired relaxation and restriction to filling affect diastolic right ventricular function in children with repair of tetralogy of Fallot and pulmonary regurgitati on. Restrictive right ventricular physiology is associated with decrea sed exercise function. (C) 1996 by the American College of Cardiology