Assessment of left ventricular twist mechanics by speckle tracking echocardiography reveals association between LV twist and myocardial fibrosis in patients with hypertrophic cardiomyopathy

Abstract

We aimed to investigate whether left ventricular (LV) twist analysis can detect the extent of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM). This prospective case–control study recruited 81 consecutive patients with HCM examined between January 2012 and April 2013. Data of 76 patients were analyzed after excluding 5 patients whose echocardiographic images were of poor quality. Healthy volunteers (n = 46) served as controls. Both groups underwent comprehensive echocardiographic examination (i.e., Bas-Rotation, AP-Rotation, LVEF, LADs, IVST, LAVi, E/Em, LVMI, advanced LV-twist analysis by speckle tracking echocardiography) and magnetic resonance imaging. Between-group differences were analyzed by independent t test; logistic regression analysis was performed to identify effect factors. No significant differences were found between baseline characteristics of HCM and control groups (all p > 0.05). HCM patients had significantly higher Bas-Rotation, AP-Rotation, LV Twist, LVEF, LADs, IVST, LAVi, E/Em and LVMI than controls (all p < 0.0001) and significantly lower LVDd and E/A (both p < 0.001). Bas-Rotation, AP-Rotation, LV-Twist, LADs, IVST, LAVi, E/Em and LVMI were significantly higher in HCM patients with fibrosis than in those without fibrosis (p < 0.001), but no significant differences in other echocardiographic parameters were found between those with and without fibrosis. Age, Bas-Rotation, AP-Rotation, LV twist, LADs, IVST, LAVi, E/A, E/Em, and LVMI were significant effect factors for fibrosis. AUROC analysis showed that LV twist had high discriminatory power to detect extent of myocardial fibrosis (AUC 0.996, 95 % CI 0.989–1.004, p < 0.001). Left ventricular twist mechanics are associated with the extent of myocardial fibrosis. LV-twist assessment by STE may be clinically useful.Electronic supplementary materialThe online version of this article (doi:10.1007/s10554-014-0509-6) contains supplementary material, which is available to authorized users.

Modern Imaging Techniques in Cardiomyopathies

“…Torsion is attenuated in early stages of nonobstructed HCM and reduced with significant obstruction. 105,106 Similar results have been reported for amyloidosis. 107,108 However, clinical utility is somewhat limited because of significant variations in normal torsion values, and torsion currently is considered a research tool rather than an established clinical modality.…”

Torsion Mechanics as an Indicator of More Advanced Left Ventricular Systolic Dysfunction in Secondary Mitral Regurgitation in Patients with Dilated Cardiomyopathy: A 2D Speckle-Tracking Analysis

“…Magnetic resonance imaging with tissue tagging is accepted as a gold standard, since it is able to create noninvasive markers over the entire myocardium [12, 13]. Echocardiographic measurement of rotation and twist in healthy persons by Philips machines was reported [14, 15]. The mean values were: BR –3.4° ± 0.6°, AR 6.6° ± 1.9°, and twist 10.02° ± 2.1° [15].…”

Speckle tracking imaging in hypertrophic cardiomyopathy

“…Myocardial twist has been associated with myocardial fibrosis and the type of hypertrophy in HCM [4]. In particular, untwist alterations have been observed in HCM mutation carriers [5,6], implying that distortion of ventricular mechanics in HCM is not entirely due to myocardial disarray but begins primarily as a result of impaired actin-myosin interaction kinetics [7].…”