Editorial Comment Left Ventricular Structure and Function in Aortic Valve Disease

C hanges in left ventricular volume, mass, and systolic performance that develop after valve replacement for chronic aortic valve disease have for years provided clinical insights into the effects of severe pressure or volume overload on the human left ventricle. These changes in left ventricular structure and function after operation See p 744 also have important implications regarding postop-erative prognosis, especially in patients with evi-dence of preoperative left ventricular dysfunction. In the majority of such patients, systolic function is reversibly depressed, the depression being related to the long-standing pressure or volume overload; aortic valve replacement in these patients results in substantial regression of hypertrophy and improve-ment in systolic function.1 However, in a subgroup of patients, more commonly those with pure or predominant aortic regurgitation, left ventricular dysfunction reflects irreversible myocardial changes in addition to altered ventricular loading and is not reversed by operation. These patients with persis-tent ventricular dysfunction after operation have a poor outcome with regard to symptoms and sur-vival. The preoperative identification of patients with these irreversible myocardial changes on the basis of standard measures of left ventricular vol-ume, hypertrophy, and function has proven to be problematic and elusive. Numerous studies over the past 2 decades have addressed the alterations in left ventricular wall stress, hypertrophy, dilatation, and systolic func-tion that develop in the course of aortic stenosis or regurgitation as well as those alterations that occur in response to aortic valve replacement. Few stud-ies, however, have focused on the alterations in myocardial cellular structure that underlie these preoperative and postoperative changes or on the cellular abnormalities that may signify irreversible ventricular dysfunction. The study of Krayenbuehl and associates2 in this issue is an important contri-bution that provides new insights into the structura