Abstract 13989: Distinguishing Focal Fibrotic Lesions and Non-Fibrotic Lesions in Hypertrophic Cardiomyopathy by Assessment of Regional Myocardial Strain using Two-Dimensional Speckle Tracking Echocardiography: Comparison with Multislice CT
Purpose: In hypertrophic cardiomyopathy (HCM), focal fibrotic lesions are frequently observed in magnetic resonance imaging or multislice CT (MSCT). The presence of fibrotic lesions may be associated with the occurrence of ventricular arrhythmia or transition to the dilated phase. It is therefore important to distinguish between focal fibrotic and non-fibrotic lesions in HCM. To this end, we compared the use of two-dimensional speckle tracking transthoracic echocardiography (TTE) with MSCT to measure regional myocardial strain values.
Method And Materials: 10 consecutive HCM patients (8 males, mean 63.4 yrs) underwent TTE. Those with ischemic heart disease or moderate-to-severe valvular disease were excluded. After recording a 3 chamber view from the apex using speckle tracking TTE (iE-33, Philips), we analyzed peak myocardial radial (RS) and longitudinal (LS) strain in each segment in the left ventricle (LV), among 17 segments as classified by AHA. This was done off-line using auto-analyzing software (QLAB). All subjects underwent enhanced MSCT (Light Speed Ultra 16). Fibrotic lesions in the LV myocardium were identified by defects in enhancement in the early phase and abnormal enhancement in the late phase. Peak RS and LS at base, mid- and apical levels were measured in fibrotic and non-fibrotic sites in the LV by MSCT.
Results: In TTE, of 170 segments from 10 patients, 143 (84.1%) yielded good tracking. Of these, 20 showed fibrotic changes in MSCT. Peak RS (%) was not significantly different between fibrotic and non-fibrotic lesions at any level (RSs at base 9.96±7.06 vs 13.81±8.37, at mid 7.22±5.19 vs 13.81±8.37 and at apical level 12.38±6.67 vs 18.30±4.28 in fibrotic and non-fibrotic lesions, respectively. Absolute values of peak LS (%), however, were significantly lower in fibrotic than non-fibrotic lesions (LSs at base −6.29±3.58 vs −11.13±6.23 (P<0.05), at mid −5.64±2.19 vs −11.13±6.23 (P<0.05) and at apical level −5.41±1.45 vs −12.68±7.31 (P<0.01).
Conclusion: In HCM, peak LS was significantly lower in fibrotic than non-fibrotic sites, as demonstrated by MSCT. Regional LS by speckle tracking can provide useful information noninvasively to distinguish fibrotic from non-fibrotic lesions in HCM.
- © 2010 by American Heart Association, Inc.