Empiric determination of the transition from concentric hypertrophy to congestive heart failure in essential hypertension

Abstract

Objectives: Our aim was to determine whether there is a final transition from left ventricular hypertrophy to congestive heart failure in the late stage of essential hypertension.

Background: A theoretic model using the concept of systolic transmural nonuniform wall thickening was applied to develop a concentric two-shell geometry allowing evaluation of the mechanics of circumferential midwall fibers.

Methods: We evaluated pressure-volume data from 46 normal control subjects (control group) and 70 patients with hypertension: 33 without hypertrophy (hypertension only group), 14 with hypertrophy (hypertrophy group) and 23 with heart failure in addition to hypertrophy (heart failure group).

Results: End-diastolic volume index was higher in the heart failure group than in the control group (p < 0.01). Although left ventricular wall thickness and mass index were increased in both the hypertrophy and the heart failure group, concentricity indexes as assessed by ratios of left ventricular wall thickness to dimension and mass index to end-diastolic volume index were maximal in the former. Although endocardial and standard midwall fractional shortening did not differ among the control, hypertension only and heart failure groups, that of the modified midwall by concentric two-shell geometry was decreased in the hypertrophy and the heart failure groups (p < 0.05). The Hotelling T2 test and Mahalanobis distance clearly discriminated the latter two groups with end-systolic stress and modified midwall fractional shortening relation.

Conclusions: A fitting segmented regression model predicted a progression to hypertrophy and identified a transition from hypertrophy to heart failure by a combination of modified midwall fractional shortening and concentricity indexes.