Abstract 12811: Two-Dimensional Speckle-Tracking Echocardiographic LV Myocardial Multi-Layer Strain-Determined Compensatory Mechanism in HCM and Severe Aortic Stenosis Patients With Preserved LV Ejection Fraction
Introduction: A multi-layer technique of speckle-tracking transthoracic echocardiography (TTE) can produce quantitative strain measurements of endocardial and epicardial layers of the left ventricle (LV) to evaluate myocardial function and characteristics.
Aim: To evaluate compensatory mechanisms in hypertrophic cardiomyopathy (HCM) and severe aortic stenosis (AS) subjects, both with hypertrophied LV myocardium and preserved ejection fraction (EF), we measured 2D LV global longitudinal (GLS) and circumferential strain (GCS) using speckle TTE, and compared the findings to controls.
Methods: Eighty subjects, 40 with HCM (30 male, 62±15 yrs, 5 Maron type 2, 16 Maron type 3, 14 Maron type 5, and 5 Maron type 2 or 3+5), 20 with severe AS (12 male, 74±5 yrs, transaortic maximum velocity 4.9±0.6 m/s, aortic valve area index 0.45±0.13 cm2/m2), and 20 controls (10 male, 59±10 yrs) underwent TTE (Vivid E9, GE Healthcare). Apical 4-, 2-, and 3-chamber views for GLS and parasternal short-axis views at the level of mitral valve, papillary muscle, and apex for GCS were acquired. Quantitative strain measurements of endocardial and epicardial layer were performed.
Results: GLS values were significantly smaller in the HCM subjects than severe AS subjects and controls (all P<0.001), and GLS values were significantly smaller in severe AS subjects than controls in the endocardial and epicardial layers (all P<0.01). There were no significant differences in endocardial GCS at the level of mitral valve and papillary muscle between the groups. Endocardial GCS at the mitral valve and papillary muscle level was significantly positively correlated with LV EF (R=0.446 and 0.34, respectively) in the HCM subjects. Similarly, in severe AS subjects, endocardial GCS at the mitral valve and papillary muscle levels was significantly positively correlated with LV EF (R=0.59 and 0.609, respectively).
Conclusions: In HCM and severe AS patients with preserved LV EF, GLS from each was significantly smaller than controls. We speculate that in such subjects, endocardial GCS at the mitral valve and papillary muscle levels is maintained in compensation for GLS decrement, and possible may contribute to maintaining LVEF.
Author Disclosures: K. Ozawa: None. N. Funabashi: None. H. Takaoka: None. Y. Kobayashi: None.
- © 2014 by American Heart Association, Inc.