Echocardiographic strain in hypertrophic cardiomyopathy and hypertensive left ventricular hypertrophy.

Abstract

The myocardial structure differs between secondary left ventricular hypertrophy (LVH) and hypertrophic cardiomyopathy (HCM). We investigated left ventricular function of these two types of hypertrophy using multilayer strain analysis with two-dimensional echocardiography. Transthoracic echocardiography (Vivid-E9) was performed in 240 patients with preserved left ventricular ejection fraction (LVEF ≥50%) and with either HCM (n=80, 63 men, age 49.8±14.1years), hypertensive LVH (n=80, 63 men, age 51.4±13.3years) or normal blood pressure and left ventricular structure (n=80, 63 men, 50.8±12.4years). Quantitative multilayer longitudinal strain (LS), circumferential strain (CS), and radial strain (RS) were analyzed. The ratio of endo-/epi-myocardial strain was calculated. Longitudinal strain was significantly (P<0.001) lower in HCM patients than normal controls (15.2±4.2% vs 23.1±2.7%), especially in hypertrophic segments (14.5±4.4% vs 17.2±3.2% in nonhypertrophic segments, P<0.01). LS was lower in patients with hypertensive LVH, similarly in all left ventricular segments (20.7±3.7%, P<0.001 vs controls). CS was lower in the mid- and epicardium (P<0.01), but not endocardium in HCM (P=0.4), and preserved in all myocardial layers in hypertensive LVH. The endo-/epi-myocardial ratios of both LS and CS were higher in HCM than hypertensive LVH (P<0.01). RS was higher (P<0.01) in HCM than hypertensive LVH and controls. Endocardial CS and global RS were correlated with LVEF (r≥0.32, P<0.01). Hypertrophic cardiomyopathy patients had marked reductions in LS and CS, whereas patients with hypertensive LVH had less reduction in LS and preserved CS. The increased endo-/epi-myocardial ratios of LS and CS may be useful in differentiating HCM from hypertensive LVH.