Echocardiography overestimates left ventricular mass

Abstract

To compare measurement of left ventricular mass (LVM) by M-mode echocardiography and magnetic resonance imaging (MRI) in hypertensive subjects. A prospective study. Twenty-four untreated hypertensive patients [19 men and five women, aged 51 +/- 2 (mean +/- SEM) years, supine blood pressure 159/101 +/- 3/1 mmHg]. The Blood Pressure Unit, St Georges Hospital Medical School and Magnetic Resonance Unit, Royal Brompton National Heart and Lung Hospital, London. LVM estimated both by M-mode echocardiography and by MRI. Using three standard M-mode formulae, widely different values of LVM were obtained with echocardiography [American Society of Echocardiography (ASE) 319 +/- 21 g, Penn 273 +/- 19 g. Teichholz 191 +/- 11 g]. By MRI, the LVM was 232 +/- 11 g. The differences between MRI and echocardiography could not be explained in terms of the timing of measurements in the cardiac cycle. When single-slice MRI measurements at the appropriate level were applied to the ASE and Penn formulae, the LVM was again overestimated. Our study has shown major differences in LVM estimated using methods based on one-dimensional (echocardiography) compared with three-dimensional (MRI) data. These differences seem to be largely the result of the geometrical assumptions on which M-mode measurements are based. Our findings have important clinical implications for the assessment of the severity and response to treatment of left ventricular hypertrophy in hypertensive patients.