subaortic stenosis
Narrowing of the left ventricular outflow tract below the aortic valve, causing obstruction to blood flow.
Full Definition
Subaortic stenosis is a form of left ventricular outflow obstruction located beneath the aortic valve, most commonly caused by a discrete membrane or muscular ridge. Unlike valvular aortic stenosis, the aortic valve itself is typically normal. This condition creates unique anesthetic challenges as the obstruction can worsen with increased contractility or decreased preload. Anesthesiologists must avoid medications and maneuvers that could exacerbate the gradient, including dehydration, vasodilation, or excessive inotropic stimulation. The condition may be dynamic and can worsen significantly under stress.
Usage
Usage note: Distinguish clearly from valvular and supravalvular forms of aortic stenosis.
In Context
- "The patient's subaortic stenosis required careful anesthetic management to avoid worsening the gradient." — Anesthetic planning documentation
- "Echocardiography revealed discrete subaortic stenosis with a peak gradient of 60 mmHg." — Diagnostic imaging report