Standardization of M-mode echocardiographic left ventricular anatomic measurements

To improve standardization of echocardiographic left ventricular anatomic measurements, echographic left ventricular dimensions and mass were related to body size indexes, sex, age and blood pressure. Independent normal populations comprised 92 hospital-based subjects (64 women, 28 men) and 133 subjects from a population sample (55 women, 78 men). All measurements of chamber size, wall thickness and mass differed between men and women in both series (p < 0.01 to p < 0.001). Left ventricular mass was related most closely to body surface area among measurements of body size (r = 0.37, p < 0.01 to r = 0.57, p < 0.001) in all four groups. Indexation by body surface area eliminated sex differences in wall thicknesses and internal dimension, but a significant sex difference in left ventricular mass index persisted (89 ± 21 g/m2in men versus 69 + 19 g/m2in women in the entire series, p < 0.0001). The 97th percentile of left ventricular mass index was identical in both groups of men (136 and 132 g/m2) and women (112 and 109 g/m2). A highly significant difference in lean body mass, estimated from 24 hour urine creatine excretion, was observed between men and women (58 ± 15 versus 40 ± 13 kg, p < 0.001) and no sex difference existed in left ventricular mass indexed by lean body mass (3.4 ± 1.3 versus 3.5 ± 1.5 g/kg). Weak correlations were observed between left ventricular mass/lean body mass and systolic or diastolic blood pressure (r = 0.25, p < 0.05 and r = 0.28, p < 0.01, respectively) but not age (18 to 72 years). In conclusion: 1) left ventricular dimensions are significantly related to body surface area, 2) left ventricular mass index is 20% less in women than men but indexation by estimated lean body mass eliminates this difference, and 3) blood pressure variation in the normal range affects left ventricular mass weakly whereas age has no effect. Therefore, sex and body surface area should be used to determine clinical normal limits of anatomic left ventricular measurements; further refinement of criteria may be achieved by use of lean body mass measurements.