LATE RESULTS AFTER REPAIR OF COMPLETE ATRIOVENTRICULAR-CANAL

Twenty-five patients with complete atrioventricular canal including 10 Down's syndrome patients repaired since 1972 were analyzed with respect to their physical activities, hemodynamics, ECG, reoperation and late mortality. Follow-up period ranged from 1 to 17 years with an average of 7.0 years. There was 1 late death. Actuarial survival rate was 0.86 +/- 0.13 (mean +/- S.D.) at 12 years. Fourteen patients (70%) of 20 evaluated were in New York Heart Association functional class I, and 4 (20%) were in class II and 2 (10%) in class III. In 23 patients without pulmonary stenosis, preoperative values of peak pulmonary to systemic pressure ratio (Pp/Ps) and pulmonary to systemic arterial resistance ratio (Rp/Rs) were 0.64 +/- 0.28 and 0.36 +/- 0.31, respectively. Postoperative Pp/Ps and Rp/Rs significantly decreased to 0.37 +/- 0.14 and to 0.20 +/- 0.14, respectively. In Down patients, postoperative Pp/Ps, Rp/Rs and pulmonary arterial resistance were significantly greater than in non-Down patients (0.50 +/- 0.07 vs. 0.25 +/- 0.05, 0.30 +/- 0.13 vs. 0.10 +/- 0.03 and 4.4 +/- 1.8 vs. 1.8 +/- 0.6 units.m2, respectively). Complete heart block developed in 1 patient postoperatively. Sick sinus syndrome was observed in 3 patients, transient Mobitz II A-V block in 2, ventricular premature contractions of Lown's Grade II in 1 and atrial fibrillation in 1. Five patients demonstrated severe mitral regurgitation equal to or more than Grade III and 2 of them underwent mitral valve replacement 6 months and 12 years after the initial operation. Most of the patients were leading in active school or social lives. However, progression of pulmonary vascular obstructive disease especially in Down's syndrome patients, mitral regurgitation and heart rhythm disturbances still create late postoperative problems.