Tricuspid Atresia with Increased Pulmonary Blood Flow

a finding not duly emphasized in previous reports. Comparison of the two groups revealed significant clinical and laboratory differences. Group II patients typically presented with severe congestive heart failure and expired within the first 2 months of life. Group I patients usually presented with mild congestive heart failure which responded to therapy. Five of the latter demonstrated progressive change from increased to decreased pulmonary blood flow during their clinical course and eventually required palliative shunt procedures, four prior to the age of 2 years and one at 5 years of age. While the electrocardiogram demonstrated right atrial enlargement and left ventricular hypertrophy in both groups, the mean frontal plane axis was between -15° and -100° in group I and -75° and +750 in group II. QRS vector loops tended to be superiorly oriented in group I and inferiorly oriented in group II. Because the natural history and prognosis in these two groups differ significantly, diagnostic efforts should include determination of the relationship of the great vessels. When transposition of the great vessels is demonstrated, aortography should be performed because of the high incidence of aortic arch anomalies.