Document the level of obstruction (heart
catheterization with or without provocative testing). Quantify the severity
and anatomy of the obstruction (clinical examination, ECG, chest
radiographs, echo-Doppler, transesophageal echocardiography to define
precisely the anatomy, MRI to assess associated lesions such as pulmonary
artery stenosis or coarctation). Prophylactic antibiotics should be used as
indicated. Consider invasive intraoperative blood pressure measurement.
Perioperative cardiac monitoring is mandatory.