Congenital ventriculo-atrial communication with anomalous tricuspid valve

A case of left ventricular-right atrial communication associated with a saccular aneurysm of the septal leaflet of the tricuspid valve is presented, with inclusion of cardiac catheterization, operative, and postmortem findings. The anatomic defect involved a communication between right atrium and left ventricle at a level just below the right coronary cusp of the aortic valve through the membranous portion of the interventricular septum. Perhaps the most unusual feature of the anomaly was the presence of the deep saccular aneurysm of the septal leaflet of the tricuspid valve at the site of the defect, projecting upward into the outflow tract of the right ventricle. The preoperative differentiation of this lesion from interatrial septal defect is difficult and the individual differences observed in this case are not specific. However, the combined findings of a loud harsh systolic murmur to the left of the sternum maximal over the lower precordium, and a prominent “c” wave in the atrial pulse pressure tracing are suggestive of a ventriculo-atrial type communication when a left to right shunt exists at the atrial level. The operative demonstration of a systolic jet of oxygenated blood from a defect in the right atrial wall in the region of the tricuspid annulus is presumptive evidence of such a communication. Since the lesion has proved to be surgically correctible, the importance of its recognition is stressed.