Doppler and two-dimensional echocardiographic observations of systolic anterior motion of the mitral valve in d-transposition of the great arteries: an explanation of the left ventricular outflow tract gradient.

Echocardiographic demonstration of systolic anterior motion of the mitral valve was seen in a 17 year old patient after the Mustard operation for d-transposition of the great arteries with intact ventricular septum. An increased flow velocity was measured by continuous wave Doppler echocardiography in the left ventricular outflow tract corresponding to an estimated peak gradient of 46 mm Hg. The presence of such a gradient had been shown earlier by the postoperative cardiac catheterization.