Failure of color flow mapping to identify coronary artery to pulmonary artery fistula.

A case of coronary artery to pulmonary artery fistula presented with the typical clinical findings of asymptomatic precordial continuous murmur and small left-to-right shunt. Echocardiography with color flow mapping failed to demonstrate the fistula on three occasions, including one study performed after angiographic demonstration of the fistula site. This case illustrates the importance of angiography in patients with unexplained continuous murmurs, even when echocardiographic and color flow mapping results are normal.