Background: An important subgroup of patients with partial atrioventricular canal require an operation in the first year of life because of refractory congestive heart failure.
Methods: From June 1982 to April 1995, of 128 patients with partial atrioventricular canal, 35 patients (27%) underwent surgical treatment at less than 1 year of life. Associated cardiac anomalies were present in 22 patients. Only 7 patients (20%) had Down's syndrome. Five patients with left ventricular hypoplasia underwent aortic coarctectomy (3 patients) or Norwood operation (2 patients). The other 30 patients underwent anatomic repair in 24 cases and aortic coarctectomy in 6. The surgical results of patients submitted for anatomic repair were retrospectively correlated with the echocardiographic mitral valve diameter.
Results: There were 7 deaths (29%) after anatomic repair, 2 (22%) after aortic coarctectomy, and 2 (100%) after Norwood operation. Infants with a mitral valve diameter less than 2.5 x 10-2 m/m2 died at repair. In a mean follow-up of 73.5 months there were five secondary mitral valve plasties and three repairs after aortic coarctectomy.
Conclusions: Among patients with partial atrioventricular canal, there is an important subgroup with clinical signs of heart failure in the first year of life. Left-sided obstructive lesions and complex mitral valve anomalies seem to play a fundamental role in the clinical evolution and prognosis of these patients. The echocardiographic mitral valve diameter may be useful for determining the correct surgical indication.