Aortico-right ventricular tunnel and critical pulmonary stenosis: diagnosis by two-dimensional and Doppler echocardiography and angiography.

An infant with aortico-right ventricular (AO-RV) tunnel and critical pulmonary stenosis presented with severe distress at birth. We present the clinical, echocardiographic, and angiographic features, correlated with autopsy findings. Also we discuss the differentiation from other AO-RV communications and a theory for the embryogenesis. AO-RV tunnel should be considered in the differential diagnosis of a critically sick newborn with cyanosis, a "to and fro" murmur, and signs of right heart failure. The correct diagnosis can be made echocardiographically by demonstrating the two ends of the tunnel connecting the aorta and a dilated RV, two normal coronary arteries, and obtaining high-velocity systolic and diastolic Doppler flow signals in the tunnel. Surgical repair of this lesion is possible, and early diagnosis and a modification of the surgical procedure may help survival.