Exercise Hemodynamics and Risk Assessment in Asymptomatic Aortic Stenosis
Over a half century ago in Circulation, Dr. Paul Wood aptly described aortic stenosis (AS) as "a simple mechanical fault which, if severe enough, imposes a heavy burden on the left ventricle and sooner or later overcomes it"1. Our subsequent understanding of the pathophysiology of AS, with more sophisticated tools than those at Dr. Wood's disposal, has confirmed his concept. Severe chronic pressure overload and outflow obstruction beget left ventricular (LV) hypertrophy and its attendant myocardial fibrosis and impaired coronary vasodilator reserve, leading to LV systolic and diastolic dysfunction, progressing ultimately to the anticipated symptoms of dyspnea, angina, and presyncope or syncope, which are harbingers of death within a few years. Once symptoms develop, the treatment strategy is clear, as aortic valve replacement (AVR) improves symptoms, improves LV function, and improves survival. The indications for AVR in asymptomatic patients, however, remain less clear and the subject of ongoing debate2-4. (SELECT FULL TEXT TO CONTINUE)
- Received July 12, 2012.
- Accepted July 16, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited