Effect of age, sex, and body surface area on echocardiographic left ventricular wall mass in normal subjects.

M-mode echocardiography was used to estimate left ventricular wall mass in 136 older normal subjects (Group I: 78 men and 58 women, ages 20 to 97 years) and 105 younger normal subjects (Group II: 52 male and 53 female subjects, ages 1 day to 23 years). Echocardiographic left ventricular mass (in grams) was estimated from the following formula: left ventricular mass = 1.05 ([ left ventricular internal diastolic dimension + ventricular septal thickness (diastole) + posterior wall thickness (diastole)] - [left ventricular internal diastolic dimension]). In both groups, female subjects had a slightly smaller left ventricular mass than male subjects (mean difference 7.2% in Group I, p less than 0.05, and 3.6% in Group II, p = 0.05) for any given age and body surface area. Left ventricular mass varied linearly with body surface area and increased as a function of age. In group I subjects, echocardiographic left ventricular mass (in grams) could be estimated by the general formula: left ventricular mass = 124 (body surface area) + A +/- C, where A is the age-dependent intercept; +/- C encompasses a 95% prediction interval for normal values, which is assumed to be nearly constant (+/- 58 g); and body surface area is expressed in square meters. In the Group II (younger) subjects, with age not considered, left ventricular mass (in grams) could be estimated from the following formula: left ventricular mass = 115 (body surface area) -11 +/- C, where +/- C = +/- 32% and this 95% prediction interval varies as a percentage of the mean.(ABSTRACT TRUNCATED AT 250 WORDS)