Diastolic ventricular septal motion in atrial septal defect: analysis of M-mode echocardiograms in 31 patients.

Previous echocardiographic studies suggest that diastolic motion of the ventricular septum reflects relative filling of the right and left ventricles. We studied 31 patients with atrial septal defect by M-mode echocardiography. Early diastolic posterior ventricular septal motion (DPSM) occurred in all patients. Measurement of DPSM correlated with pulmonary to systemic flow ratios (Qp:Qs) (r = 0.64, p less than 0.001). All 15 patients with DPSM greater than 5 mm had a Qp:Qs greater than 2.5:1, whereas only 8 of 16 patients with DPSM less than 5 mm had a shunt this large (p less than 0.003). DPSM greater than 5 mm in patients with atrial septal defect is a specific but not sensitive echocardiographic sign of a large left-to-right shunt. Our findings substantiate the hypothesis that diastolic motion of the ventricular septum reflects relative filling of the ventricles.