Spontaneous regression of peripheral pulmonary artery stenosis in Williams syndrome.

An infant girl diagnosed with multiple peripheral pulmonary artery stenosis and Williams syndrome was followed-up for 17 years. Three cardiac catheterizations performed over the follow-up period showed that spontaneous gradual regression of the stenosis occurred with time. The initial systolic pressure gradient of 77-79 mmHg at the stenoses had decreased to 23-29 mmHg when measured at 17 years of age. Contrary to the progressive nature of systemic artery stenosis in Williams syndrome, peripheral pulmonary artery stenosis appears to have the capacity for spontaneous improvement. Careful consideration is required to determine the indications for interventional catheterization for the dilation of peripheral pulmonary artery stenosis in cases of Williams syndrome.