ABSTRACT
INTRODUCTION: Cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) are important differential diagnosis of left ventricular hypertrophy. The aim of this study was to investigate if three-dimensional (3D) speckle tracking-derived functional parameters enabled differentiation of CA and HCM by a disease-specific pattern. METHODS: Twelve patients with CA and 12 patients with HCM were included. CA and HCM were diagnosed by contrast-enhanced cardiovascular magnetic resonance (CMR). Three-dimensional speckle tracking echocardiography with wall motion analysis was performed for strain (radial [RS(%)], longitudinal [LS (-%)], and circumferential [CS (-%)]), rotation (ROT [degree]), and twist (TWT [degree]). Intergroup comparison included normalized values from 49 healthy volunteers. RESULTS: Averaged RS, LS, CS, ROT, and TWT were investigated at basal, midventricular, and apical levels. With some exceptions, 3D speckle tracking function parameters were mostly lower in the HCM and minimal in the CA group as compared to controls. Comparing CA and HCM, basal RS was significantly reduced in patients with amyloidosis (7.5 ± 19.7 vs. 22.3 ± 22.7; P < 0.0001), furthermore the "physiological" gradient of basoapically decreasing RS, which was reduced, but still preserved in HCM, showed a clear "inverse pattern" in patients with amyloidosis, comprising a gradual increase from base to apex. Correlation analysis of 3D speckle tracking function and CMR late gadolinium enhancement (LGE) revealed high inverse correlation of RS and LGE in CA (r =-0.82) and only mild correlation in HCM, followed by CS as second best parameter. An increasing/decreasing basoapical RS gradient yielded a sensitivity of 83% versus the CMR-derived diagnosis "CA" and "HCM." CONCLUSIONS: Three-dimensional speckle tracking echocardiography demonstrated significant differences in CA and HCM. The basoapical RS gradient displayed oppositional characteristics in CA and HCM, suggesting a "function-pattern-based" differentiation of amyloidosis and HCM.
