Evaluation of Concentric Left Ventricular Geometry in Humans

Abstract

There might be limitations in identifying concentric left ventricular (LV) geometry by ratio of diastolic posterior wall thickness (WT p ) to cavity radius, defined as relative wall thickness (RWT p ). This study has been designed to evaluate age effects on RWT p . WT p , mean of septal thickness and WT p (WT m ), and cavity radius were cross-sectionally evaluated in 766 1- to 85-year-old, normotensive, nonobese subjects and 331 hypertensive Italians (used as a test series). RWT p ≥0.43 defined “traditional” concentric LV geometry. The ratios WT m /radius (RWT m ) and RWT p increased by 0.005 and 0.006 per year of age in the age stratum up to 17 years and by 0.002 in the older age stratum (18 years or older; all P <0.0001). Thus, RWT m and RWT p were normalized to average age in both age strata (10 and 46 years) by age-specific regression coefficients. The 90th and 95th percentiles of age-normalized RWT p or RWT m were 0.40 and 0.42 or 0.41 and 0.43, respectively, in adults and 0.36 and 0.39 or 0.36 and 0.38, respectively in young subjects. In hypertensive subjects, traditional RWT p cutoff identified 74 subjects (22%) with concentric LV geometry; by 95th or 90th normal percentiles, normalized RWT m identified 112 (34%), or 149 (45%) subjects with concentric LV geometry, and normalized RWT p 29% and 39%, respectively (all P <0.0001 versus unadjusted RWT p ). Thus, prevalence of concentric LV geometry increases with age-normalized RWT. Accordingly, we suggest that concentric LV hypertrophy be defined by coexistence of high LV mass with age-normalized RWT m >0.41 or RWT p >0.40. Further studies are required to establish prognostic implications of our findings.