Doppler echocardiographic observations of diastolic trans-septal flow through small ventricular septal defects

Turbulent left-to-right trans-septal diastolic blood flow with a peak velocity greater than 0.5 m.s-1 was detected by pulsed Doppler echocardiography in 10 out of 204 (4.9%) children with isolated small ventricular septal defects. For children older than 10 years, it was observed in over a quarter of cases (27%). Peak diastolic velocities ranged from 0.6-1.9 m.s-1 (mean 1.2 m.s-1) and in all patients the duration of diastolic flow exceeded that of the systolic trans-septal jet. Three different patterns of diastolic flow were observed and in eight cases pre-systolic acceleration was present. Turbulent diastolic flow across small ventricular septal defects is a common finding in older children and should not be confused with other causes of disturbed diastolic flow within the right ventricle.