Krongrad, Ehud

During cardiac catheterization in nine patients with ventricular septal defect and seven patients with truncus arteriosus, all with severe pulmonary vascular obstructive disease, hemodynamics were compared while they were breathing first room air and then 100% oxygen. Patients with higher pulmonary vascular resistance had higher systemic vascular resistances. With 100% oxygen, pulmonary vascular resistance decreased and systemic vascular resistance increased in both groups. The effect of oxygen was found to be more pronounced on the systemic than on the pulmonary vascular bed in the patients studied. Indicator-dilution dye curves changed and exhibited characteristics of left-to-right shunts in patients with severe pulmonary vascular obstructive disease, as a result solely of an increase in systemic resistance; that is, without a decrease in pulmonary resistance. It is suggested that in patients with severe pulmonary vascular obstructive disease maintenance of an increased systemic resistance is essential to well being and is a factor in longevity. It is also suggested that any transient decrease in systemic resistance in these patients might initiate a vicious cycle leading to sudden death.

Five patients have had the common features of pulmonary atresia or severe stenosis associated with a septal defect and a coronary artery-to-pulmonary artery (CA-PA) fistula. Four had pulmonary valvular atresia, and one had severe pulmonary stenosis. In all five, the CA-PA fistula contributed the principal component of the pulmonary blood flow. Cyanosis, continuous murmur, right ventricular hypertrophy, and decreased or normal pulmonary vascularity were frequent clinical manifestations, but angiocardiography was required to establish the diagnosis. The fistula was a side-to-side communication between the left coronary artery and the main pulmonary artery in each of the five patients. The dilated proximal coronary artery connecting the aortic root with the pulmonary artery gave a unique angiocardiographic appearance distinguishing it from truncus arteriosus or aorticopulmonary window. It is suggested that this unique angiocardiographic appearance be called an "aorticopulmonary tunnel." The surgical repair of this anomaly is closely related to that for severe tetralogy of Fallot and should involve a comparable risk and achieve a comparable result.

Scalar electrocardiograms of 31 patients with double-outlet right ventricle (19 with and 12 without pulmonary stenosis) were correlated with the hemodynamic and anatomic findings. Atrioventricular conduction defects, intraventricular conduction delay, and counterclockwise frontal-plane loops were found less often than formerly reported. Counterclockwise frontal-plane loops were found with, as well as without, pulmonary stenosis. The presence or absence of left ventricular hypertrophy did not correlate with the severity of pulmonary vascular obstructive disease. Electrocardiographic evidence of left atrial enlargement was difficult to interpret. Additional intracardiac malformations could not be appreciated from the electrocardiographic findings. The predictive value of the electrocardiogram for the diagnosis of double-outlet right ventricle was considered to be low. In patients with double-outlet right ventricle without pulmonary stenosis, the electrocardiogram was not helpful in predicting the severity of pulmonary vascular obstructive disease.