Effects of hypertrophy on contractile function in man.

In patients with chronic pressure and volume overload matched with respect to elevated left ventricular muscle mass contractile function assessed by isovolumic as well as by ejection phase indexes is depressed to a similar extent. Pressure overload hypertrophy in aortic stenosis is associated with a reduced inotropic state of the individual contractile units. Despite this diminution of contractility hypertrophy may be effective in maintaining a normal ejection fraction as long as afterload does not become excessive. Aortic valve replacement leads to a significant reduction of the preoperatively elevated ventricular muscle mass and to a significant improvement of contractile function.