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 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.(ABSTRACT TRUNCATED AT 250 WORDS)