Evaluation of concentric left ventricular geometry in humans: Evidence for age-related systematic underestimation

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 Pm 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 Pp). 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.