Abstract 13951: Myocardial Mechanics in Hypertrophic Cardiomyopathy: Correlations with Late Gadolinium Enhancement
Background: In hypertrophic cardiomyopathy (HCM), myocyte hypertrophy, fiber disarray, and interstitial fibrosis interfere with both systolic and diastolic myocardial mechanics despite clinically hyperdynamic systolic function. In these patients, myocardial fibrosis as measured by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) is an independent predictor of adverse outcome. We aimed to assess differences in global myocardial mechanics based on degree of LGE.
Methods: Cine SSFP CMR data sets of 40 patients with non-obstructive HCM (20 no LGE, 20 severe LGE) and a normal LVEF (>55% by CMR) were analysed using Velocity Vector Imaging (echocardiography-based software) to quantify global systolic and diastolic myocardial mechanics (16-segment average).
Results: LV mass index (LVMI) and maximal wall thickness (MWT) were significantly higher in the group with severe LGE compared with no LGE, whereas the LVEF was lower. Both circumferential and longitudinal strain and strain rates were significantly lower in the group with severe LGE. For the entire group, there was a correlation between both longitudinal (r=0.37; p=0.02) and circumferential strain and LVEF (r=0.6; p<0.01). Longitudinal strain correlated with both LVMI (r=-0.41; p<0.01) and MWT (r=-0.48; p<0.01), but circumferential strain was not related to either.
Conclusions: In patients with severe LGE on CMR, there is a significant reduction in strain compared with those patients without LGE. Although both circumferential and longitudinal strain correlated with LVEF, only longitudinal strain appeared to be related to degree of hypertrophy.
- © 2011 by American Heart Association, Inc.