Supravalvular aortic stenosis

Overview
Supravalvular aortic stenosis is the most uncommon cause of left ventricular outflow tract obstruction (LVOT) accounting for 8% of congenital cases of LVOT obstruction.

Pathophysiology

 * 1) Obstruction occurs just above the coronary ostium at the level of the sinotubular junction:
 * 2) *Hourglass type (the most common)
 * 3) *Hypoplastic type: uniform narrowing of the ascending aorta.
 * 4) Associated lesion is peripheral pulmonary arterial stenosis
 * 5) Because of high perfusion pressure of the coronary arteries there is premature coronary artery disease.
 * 6) Coronary arteries may be obstructed by an adjacent stenotic ring.

Genetics

 * 1) One third of cases are transmitted as an autosomal dominant trait.

Physical Examination

 * 1) 50% have a characteristically greater pulse and systolic blood pressure in the right carotid and brachial arteries than in the left.
 * 2) The systolic murmur is maximal below the right clavicle and radiates primarily to the right carotid artery.
 * 3) No ejection click is present, no diastolic murmur.