Echocardiographic Left Ventricular Mass in a Multiethnic Southeast Asian Population: Proposed New Gender and Age-Specific Norms

Background: Left ventricular mass (LVM) is an independent risk factor for cardiovascular outcome. We aimed to define normal reference values of LVM/body surface area (BSA) in a multiethnic Southeast Asian population across ages, and define demographic parameters that predict LVM/BSA. Methods: 198 subjects (44% men, mean age 40 ± 14 years, 82% Chinese, 13% Malay and 5% Indian) with no cardiovascular comorbidity and had normal echo images for age were included in the analysis. Echo LVM was calculated as: 1.04 ×[(left ventricular internal diameter at end-diastole {LVIDd}+ interventricular septal thickness at end-diastole {IVSd}+ left ventricular posterior wall thickness at end-diastole {LVPWd})³− LVIDd³× 0.8]+ 0.6¹, indexed by BSA (LVM/BSA)* and expressed as g/m². Results: BSA and blood pressure (BP) were comparable between dichotomous age groups < or ≥ 50 years within the same gender. Women aged ≥ 50 years had larger IVSD, LVPWd, LVM and LVM/BSA compared to younger cohort. (p < 0.01 for all variables). The 95th percentile of LVM in men and women were 189 g and 148 g respectively; corresponding values for LVM/BSA were 106 and 96 g/m². These values are consistently smaller than published values from the West. Age (r = 0.27, P < 0.001), gender (r =−0.30, P < 0.001), and systolic BP (r = 0.25, P = 0.003) were significant univariate predictors of LVM/BSA. Conclusion: We therefore propose a different cutoff value for the diagnosis of LV hypertrophy among Southeast Asians.