Morphometric Structure of the Failing Left Ventricular Myocardium in Aortic Valve Disease Before and After Valve Replacement

Abstract

Chronic pressure and/or volume overload in aortic valve disease is associated with marked left ventricular angiographic [l–3] as well as cellular hypertrophy [4,5]. This process of secondary hypertrophy is accompanied by an increase in interstitial tissue. Are the microscopic alterations different in patients with preserved and depressed left ventricular function? Comparing intraoperative transmural biopsies from patients with compensated and decompensated aortic stenosis, Schwarz et al. [6] found a reduced volume fraction of myofibrils in those with depressed left ventricular function. In patients with aortic insufficiency and a massively impaired left ventricular ejection fraction of 32%, volume fraction of myofibrils was smaller and muscle fiber diameter larger than in patients with aortic insufficiency and only a moderately depressed ejection fraction of 48% [7]. The purpose of the present study was to evaluate left ventricular morphometric structure from endomyocardial biopsies in patients with aortic valve disease with compensated and failing left ventricles and to report changes of morphometric variables at an intermediate time after aortic valve replacement.

This work was supported by a grant from the Swiss National Science Foundation.