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 clinical and epidemiologic studies. Doubts regarding the ability of this approach to obtain a precise estimate of left ventricular weight across a wide range of values have recently been raised and an alternate thin-wall ellipsoidal model has been proposed to gain greater precision.


OBJECTIVE
To compare thin-wall and thick-wall (American Society of Echocardiography and Penn convention) models for calculation of left ventricular mass.


METHODS
Validation, cross-sectional, and longitudinal studies.


METHODS
Necropsy data and living cohorts from Naples, New York City, and Umbria region of Italy (PIUMA registry).


RESULTS
The average thin-wall left ventricular mass was slightly greater than the necropsy left ventricular weight (mean 225 versus 220 g), whereas no difference 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 mass while slightly underestimating the highest values. Comparison of Cox proportional hazard models in two longitudinal studies demonstrated that there was a substantial equivalence among methods, with a marginally better performance of thick-wall models for cardiovascular risk stratification (P < 0.05 in one study).


CONCLUSIONS
Although it is imperfect, because it is based on simplifying geometric assumptions, computation of left ventricular mass on the basis of M-mode echocardiographic left ventricular dimensions using thick-wall prolate-ellipsoidal models is valuable for identification of left ventricular hypertrophy and for cardiovascular risk stratification of patients with essential hypertension. Calculation of left ventricular mass by use of a thin-wall prolate-ellipsoidal geometry does not yield appreciably different results than those which are obtained by use of thick-wall models.
de Simone
G
G
Department of Clinical and Experimental Medicine, Federico II University Hospital, School of Medicine, Naples, Italy. simogi@unina.it
Verdecchia
P
P
Schillaci
G
G
Devereux
R B
RB
D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D003430:Cross-Sectional Studies; D004452:Echocardiography / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015233:Models, Statistical; D009519:New York City / Q000453:epidemiology; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors