CLINICAL IMPACT OF VARIOUS GEOMETRIC-MODELS FOR CALCULATION OF ECHOCARDIOGRAPHIC LEFT-VENTRICULAR MASS

Background. M-mode echocardiographic left ventricular mass calculated using a thick-wall prolate ellipsoidal model is widely used in clinica l and epidemiologic studies. Doubts regarding the ability of this appr oach to obtain a precise estimate of left ventricular weight across a wide range of values have recently been raised and an alternate thin-w all ellipsoidal model has been proposed to gain greater precision. Obj ective. To compare thin-wall and thick-wall (American Society of Echoc ardiography and Penn convention) models for calculation of left ventri cular mass. Design. Validation, cross-sectional, and longitudinal stud ies. Participants. Necropsy data and living cohorts from Naples, New Y ork City, and Umbria region of Italy (PIUMA registry). Results. The av erage thin-wall left ventricular mass was slightly greater than the ne cropsy left ventricular weight (mean 225 versus 220 g), whereas no dif ference was detected using regression-adjusted thick-wall methods. Use of the thin-walled model slightly overestimated left ventricular mass relative to both thick-wall models at the lowest left ventricular mas s while slightly underestimating the highest values, Comparison of Cox proportional hazard models in two longitudinal studies demonstrated t hat there was a substantial equivalence among methods, with a marginal ly better performance of thick-wall models for cardiovascular risk str atification (P < 0.05 in one study). Conclusions Although it is imperf ect, because it is based on simplifying geometric assumptions, computa tion of left ventricular mass on the basis of M-mode echocardiographic left ventricular dimensions using thick-wall prolate-ellipsoidal mode ls is valuable for identification of left ventricular hypertrophy and for cardiovascular risk stratification of patients with essential hype rtension. Calculation of left ventricular mass by use of a thin-wall p rolate-ellipsoidal geometry does not yield appreciably different resul ts than those which are obtained by use of thick-wall models. J Hypert ens 16:1207-1214. (C) 1998 Lippincott-Raven Publishers.