Figure 50-17 Pathophysiology of aortic stenosis. Left ventricular (LV) outflow obstruction results in increased LV systolic pressure, increased LV ejection time (LVET), increased LV diastolic pressure, and decreased aortic (Ao) pressure. Increased LV systolic pressure with LV volume overload increases LV mass, which may lead to LV dysfunction and failure. Increased LV systolic pressure, LV mass, and LVET increase myocardial oxygen (O₂ ) consumption. Increased LVET results in a decreased myocardial perfusion time. Increased LV diastolic pressure and decreased Ao diastolic pressure decrease coronary perfusion pressure. Decreased diastolic time and coronary perfusion pressure decrease myocardial O₂ supply. Increased myocardial O₂ consumption and decreased myocardial O₂ supply produce myocardial ischemia, which causes further deterioration in LV function. ↑, Increased; ↓, decreased. (Redrawn from Braunwald E: Heart Disease: A Textbook of Cardiovascular Medicine. Philadelphia, WB Saunders, 1980, p 1162.)