MIDWALL FRACTIONAL SHORTENING IS AN INDEPENDENT PREDICTOR OF LEFT-VENTRICULAR DIASTOLIC DYSFUNCTION IN ASYMPTOMATIC PATIENTS WITH SYSTEMIC HYPERTENSION

Conventional measures of left ventricular (LV) systolic performance su ggest that diastolic dysfunction precedes the development of systolic dysfunction in hypertension, Midwall fractional shortening is a new me asure of systolic function that identifies hypertensive patients who h ave evidence of target-organ damage, impaired contractile reserve, and increased mortality. We therefore sought to determine whether depress ed midwall fiber shortening is associated with abnormal diastolic func tion. Echocardiograms were obtained in 102 otherwise healthy hypertens ive patients without treatment with normal conventional measures of sy stolic function. Of these, 15 had depressed midwall shortening based o n previously described normative relations. Patients with depressed mi dwall shortening had slightly higher blood pressure, Abnormal diastoli c function, defined as late (A) LV inflow velocity greater than early (E) velocity, was observed in 33% of those with normal midwall shorten ing but in 60% of those with depressed shortening (p <0.05). Patients with A/E >1 had lower absolute midwall fiber shortening (15 +/- 3% vs 18 +/- 3%, p <0.0001) but similar endocardial shortening. Patients wit h abnormal midwall shortening had higher A/E and longer isovolumic rel axation times (both p <0.05). In multivariate analysis, midwall fracti onal shortening, age, and heart rate were independent predictors (p <0 .01) of A/E in a model including blood pressure, LV mass, and endocard ial shortening. We conclude that subnormal midwall shortening predicts LV diastolic abnormalities in this population of hypertensive patient s with otherwise normal measures of LV systolic function, Contrary to our previous understanding, depressed LV systolic performance, when id entified with this newer method, occurs coincidentally with impaired d iastolic function. (C)1998 by Excerpta Medica, Inc.