Assessment of left-ventricular mass and remodeling in obese adolescents: M-mode, 2D or 3D echocardiography?

Although there have been several studies about the impact of obesity on left-ventricular mass (LVM) and remodeling and their influence on cardiovascular morbidity and mortality, no studies are available on the best echocardiographic technique to study them. In addition, the role of systemic hypertension on LVM in obese adolescents has not been adequately investigated.

To compare LVM and remodeling pattern assessed by M-mode, two-dimensional (2D) and three-dimensional (3D) echocardiography in obese adolescents, and to correlate LVM with 24-h ambulatory blood pressure measurements.

We studied 120 adolescents: 86 obese patients by M-mode, 2D and 3D echocardiography and 34 normal individuals by echo and magnetic resonance imaging (MRI).

In normal individuals LVM was assessed by 3D echo and had the strongest correlation to MRI. In obese adolescents left-ventricular geometry was abnormal in 27 patients (31%) by 3D echo, in 21 patients (24%) by 2D echo and in 43 patients (50%) by M-mode. Mean SBP was significantly related to relative wall thickness, body mass index (BMI) and LVM/h evaluated by 3D echo [r=0.52 (P<0.0001), r=0.36 (P=0.004) and r=0.28 (P=0.03), respectively]. However, at a multivariate analysis, BMI showed a stronger correlation with LVM/h assessed by 3D compared to mean SBP (r=0.44 and P=0.001 vs. r=0.26, P=0.1).

In young patients LVM assessed by 3D echo had the strongest correlation to MRI compared to 2D and M-mode echo. In obese adolescents, 3D echo showed left-ventricular remodeling in 31% with LVM more significantly correlated with BMI compared to mean SBP.