Abstract
BACKGROUND: Right ventricular (RV) functional abnormalities significantly impact the clinical presentation and prognosis of hypertrophic cardiomyopathy (HCM) patients. The aim of this study was to assess RV systolic function across the three myocardial layers using two-dimensional speckle tracking echocardiography (2D-STE) and its derived layer-specific strain (LSS) in HCM patients with or without RV hypertrophy (RVH). METHODS: This cross-sectional study consecutively enrolled 102 HCM patients (HCMs) and 50 healthy controls (HCs). Patients with HCM were divided into two groups based on the presence or absence of RVH, according to RV wall thickness (RVWT). RV and left ventricular (LV) echocardiographic parameters were assessed using conventional echocardiography, tissue Doppler imaging (TDI), and 2D-STE. RESULTS: Significant differences were observed in RV global longitudinal strain (RVGLS), RVGLSendo, RVGLSmid, RVGLSepi, RV free wall strain (RVFWS), RVFWSendo, RVFWSmid, and RVFWSepi among the three groups (all P<0.05). The HCMs with or without RVH showed significantly lower absolute values of RVGLS, RVGLSendo, RVGLSmid, RVGLSepi, RVFWS, RVFWSendo, RVFWSmid, and RVFWSepi compared to the HCs (all P<0.05). Moreover, HCM patients with RVH exhibited significantly lower absolute values of RVGLS, RVGLSendo, RVGLSmid, RVGLSepi, RVFWS, RVFWSendo, RVFWSmid, and RVFWSepi compared to the HCMs without RVH (all P<0.05). Furthermore, RVWT was significantly associated with tricuspid annular plane systolic excursion (TAPSE), RVGLS, RVGLSendo, RVGLSmid, RVGLSepi, RVFWS, RVFWSendo, RVFWSmid, or RVFWSepi (all P<0.05). LV end-systolic volume index (LVESVi) was significantly associated with RVGLS, RVGLSmid, RVGLSepi, RVFWS, RVFWSendo, RVFWSmid, and RVFWSepi (all P<0.05). LVGLS was significantly associated with TAPSE, RVGLS, RVGLSendo, RVGLSmid, RVGLSepi, and RVFWSepi (all P<0.05). There were positive correlations between chest pain or New York Heart Association (NYHA) grade, and RVGLS, RVGLSendo, RVGLSmid, and RVGLSepi, and positive correlations between arrhythmia and RVGLS, RVGLSendo, RVGLSmid, RVGLSepi, RVFWS, RVFWSendo, RVFWSmid, and RVFWSepi (all P<0.05). CONCLUSIONS: This study revealed that absolute values of the RV systolic function decreased significantly in HCM patients, as characterized by reduced absolute values of RVGLS and RVFWS across all three myocardial layers, particularly in HCM patients with RVH. LSS of RVGLS and RVFWS could serve as indicators of increased risk for chest pain, NYHA grade, and arrhythmias.