Pulmonary venous flow in large, uncomplicated atrial septal defect

Background: The pulmonary venous flow velocity pattern (PVFVP) in atrial se ptal defect (ASD) has not been previously studied in detail. Normally, PVFV P is primarily determined by the left heart performance. We hypothesized th at the impact of left-sided heart dynamics on PVFVP;P is diminished in pati ents with ASD because of the presence of a left-to-right shunt into the loc i-resistance right side of the heart. Methods and Results: Transesophageal echocardiography was performed in 19 a dults and 3 children with a large, uncomplicated secundum ASD (maximum diam eter 0.6 to 3.0 cm). All patients were in normal sinus rhythm with an avera ge heart rate of 78 bpm in adults and 116 bpm in children. In 21 subjects t he antegrade PVFVP lacked distinct systolic (S) and diastolic (D) waves, In stead, we observed a single continuous antegrade wave extending from the be ginning of systole to the onset of atrial contraction, Furthermore, the amp litude of the atrial reversal (AR) wave was smaller than in historical cont rols. In 3 patients in whom ASD was surgically repaired, we observed an imm ediate return of distinct Sand D waves postoperatively. This confirmed that PVFVP abnormality was indeed the result of the ASD, Also a large increase in the AR wave amplitude (46 + 15 cm/s) was noted postoperatively Conclusions: This previously unrecognized PVFVP comprising a single continu ous antegrade Nave and a diminished,SR wave sheds new light on the hemodyna mics of ASDs. Its presence may also alert the echocardiographer to the poss ibility of an ASD when the septal defect cannot be visualized directly.