Abstract 12723: 2D Speckle Tracking Myocardial Strain Gradients Have Positive Relationship With the Degree of Hypertrophy in LV Myocardium for Hypertrophic Cardiomyopathy and Severe Aortic Stenosis With Different Mechanism. A Novel Multi-Layer Technique TTE Study
Introduction: A novel multi-layer technique on speckle tracking TTE can achieve quantitative strain measurements of all, subendocardial, and subepicardial layer of left ventricle (LV), respectively.
Aim: To compare characteristics of hypertrophic LV myocardium between hypertrophic cardiomyopathy (HCM) and severe aortic stenosis (AS) both with preserved LV ejection fraction (EF) >50%, we measured myocardial strain gradient by 2D LV global longitudinal (GLS) and circumferential strain (GCS) using a multi-layer technique on TTE.
Methods: 60 subjects (40 HCM (30 male; 62 ± 15 yrs) and 20 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)) underwent TTE (Vivid-E9). Apical 4, 2, and 3 chamber views for GLS and parasternal short axis views at level of mitral valve, papillary muscle, and apex for GCS were acquired. GLS was averaged from a total of 18 segments acquired from each view. We defined myocardial strain gradient as ratio of subendocardial to subepicardial strain.
Results: Averaged GLS were significantly smaller in HCM than AS subjects in all, subendocardial and subepicardial layer, respectively. GCS were significantly smaller in HCM than AS subjects at level of mitral valve in subepicardial layer and at level of apex in all and subepicardial layer. There were no significant differences of subendocardial GCS at all levels and GLS gradient from each view between both groups. However GCS gradients at level of mitral valves and apex were significantly greater in HCM than in AS subjects. In HCM subjects, GCS gradient at mitral valve and papillary muscles significantly positively correlated with inter ventricular septum thickness in end diastole (IVStd) (R = 0.363, and 0.373, respectively). In AS subjects, GLS gradient from 4 chamber view and averaged GLS significantly positively correlated with IVStd (R = 0.467 and 0.487, respectively).
Conclusions: In HCM subjects with preserved LV EF, GLS was significantly smaller than in AS subjects but there were no significant differences of GCS values and GLS gradient between both groups. GCS gradient at mitral valve and papillary muscles for HCM subjects and GLS gradient for severe AS subjects may have positive relationship with degree of LV hypertrophy.
Author Disclosures: K. Ozawa: None. N. Funabashi: None. H. Takaoka: None. Y. Kobayashi: None.
- © 2014 by American Heart Association, Inc.