Abstract 16402: Relationship Between Left Ventricular Myocardial Shortening in the Three Orthogonal Directions and Cardiovascular Complications in Patients With Nonobstructive Hypertrophic Cardiomyopathy
Background: It has been shown that longitudinal myocardial shortening is associated with cardiovascular events in patients with hypertrophic cardiomyopathy (HCM). On the other hand, we have demonstrated that intrinsic left ventricular (LV) myocardial shortening towards 3 directions is impaired in patients with HCM and preserved LV ejection fraction (EF). However, it remains unclear whether it is associated with cardiovascular complications (CCs). We thus determined the relationship between LV myocardial shortening in each of 3 orthogonal directions and CCs in patients with HCM.
Methods: Echocardiography was performed in 58 patients with nonobstructive HCM. LVEF was preserved normal (>50%) in all patients (mean ± SD: 70±7%). The peak mitral annular velocities in systole (s′) and early diastole (e′) were measured by using tissue Doppler imaging (TDI). Global longitudinal strain (GLS), circumferential strain (GCS), and radial strain (GRS) were measured by using two-dimensional speckle tracking technique. Patients were subdivided according to the presence or absence of CCs.
Results: Twenty-nine patients had CCs: heart failure in 8, ventricular fibrillation in 2, ventricular tachycardia in 12, atrial fibrillation in 8, stroke in 2, and syncope in 2. TDI-derived s′ (7.5±1.6 vs 8.5±1.9 cm/s, p<0.05), e′ (6.6±1.1 vs 7.8±2.6 cm/s, p<0.05), and speckle tracking-derived GLS (-9.4±2.9 vs -12.3±3.7%, p<0.01) were all lower in CC group than no CC group. On the contrary, GCS (-23.5±4.7 vs -25.1±5.1%, p=0.21) and GRS (35.4±16.6 vs 39.1±18.9%, p=0.41) did not differ between groups. By multivariate analysis, posterior wall thickness (PWT: OR=0.13-0.85, p<0.05) and GLS (OR=1.08-2.12, p<0.05) were the only independent predictors of CCs among LV dimension, interventricular septal thickness, PWT, LV mass index, LVEF, s′ , e′ and GLS.
Conclusions: Longitudinal, but not circumferential or radial, LV myocardial shortening was associated with cardiovascular complications in patients with nonobstructive HCM. Global longitudinal strain was the stronger predictor of their cardiovascular complications than TDI-derived parameters.
- © 2013 by American Heart Association, Inc.