Diastolic flow across a ventricular septal defect: an invitation to a false diagnosis.

A case is reported of a child with a perimembranous ventricular septal defect with extensive aneurysm formation misdiagnosed as a ruptured aneurysm of the sinus of Valsalva on the basis of a distinct diastolic jet seen on colour Doppler echocardiography. The hemodynamic explanation of this rarely recognized finding is apparent from simultaneous pressure tracings taken at the time of cardiac catheterization. Diastolic flow across a ventricular septal defect can be distinguished from a ruptured aneurysm of the sinus of Valsalva by the low velocity of the jet and its tendency to peak in late diastole.