Size matters! Impact of age, sex, height, and weight on the normal heart size.

BACKGROUND: Therapeutic decisions in cardiology are determined frequently by cardiac chamber size. To decide whether cardiac dimensions are still in the normal range, reliable reference values are needed. However, published reference values mostly refer to historical cohorts using motion-mode measurements and have not been adjusted for sex or age. The impact of body size was only vaguely addressed. The importance of such adjustments is illustrated by studies, which show that smaller individuals and women are at risk of delayed treatment and impaired outcome when currently used reference values are applied. The aim of the present study was to assess the impact of body size, sex, and age on the normal heart size.

METHODS AND RESULTS: We prospectively studied 622 individuals (52.7% women; 17-91 years; 143-200 cm; 32-240 kg) without cardiac disease by standard transthoracic echocardiography. Multivariable linear regression analyses of the impact of sex, age, height, and weight on cardiac chamber size were performed. By multivariable regression analysis (n=500), all 4 variables independently influenced cardiac chamber size. The validity of cardiac dimensions predicted by the regression model was tested prospectively in a validation cohort (n=122). A calculator is proposed that estimates cardiac dimensions on the basis of the regression analysis.

CONCLUSIONS: Sex, height, weight, and age significantly affect the normal heart size. These parameters need to be considered when cutoff values indicating the need for treatment or even surgery are established.