Severe subaortic stenosis that progressed over a 12-year period after cardiac surgery.

A 12-year-old girl who had undergone cardiac surgery for ventricular septal defect (VSD), atrial septal defect (ASD), and patent ductus arteriosus (PDA) in infancy was referred to our institution for fatigue and excessive sweating. Transthoracic and transesophageal echocardiographic studies revealed tunnel-type subaortic stenosis with aortic valvular stenosis, for which she underwent aortic valve replacement and myomectomy of left ventricular outflow tract. Progression of subaortic stenosis should be considered in patients with only mild aortic valve stenosis after previous cardiovascular surgery. Echocardiography contributed significantly to making the diagnosis and therapeutic decision in our patient.