UNUSUAL MIDSEPTAL SINUS VENOSUS DEFECT

An unusual case of an interatrial communication similar to a sinus ven osus defect associated with an overriding pulmonary venous chamber is reported. There was no direct connection of the pulmonary venous syste m with either the superior vena cava or the low right atrium, as is us ual with sinus venosus defects. This defect may represent the result o f a sinus venosus defect associated with cor triatriatum.