Abstract
INTRODUCTION: This study aims to assess left ventricular (LV) function and exercise endurance in patients with hypertrophic cardiomyopathy (HCM) using a combination of left ventricular pressure-strain loop (LV-PSL) and cardiopulmonary exercise testing (CPET) and to explore the correlation of the maximum left ventricular wall thickness (MWT) with clinical, echocardiographic, and CPET parameters. METHODS: A total of 55 patients with nonobstructive HCM, diagnosed between January 2022 and March 2023 at Longyan First Affiliated Hospital of Fujian Medical University, were included, along with 55 healthy volunteers as a control group. Two-dimensional ultrasound speckle tracking technology was used to obtain global longitudinal strain (GLS), longitudinal strain peak time dispersion (PSD), as well as the myocardial global work index (GWI), myocardial global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). The differences in these parameters were compared between the two groups before and after CPET. CPET was used to measure peak oxygen consumption (Peak VO(2)), anaerobic threshold (AT), ventilation equivalent for carbon dioxide slope (VE/VCO(2) slope), oxygen pulse (VO(2)/HR), and metabolic equivalents (METs), and the differences between the two groups were also compared. RESULTS: Compared to the control group, the HCM group showed significant reductions in GLS, GWI, GCW, and GWE, while GWW and PSD were significantly increased, with statistical significance (p < 0.05). Peak VO(2), AT, VO(2)/HR, and METs were significantly lower in the HCM group compared to the control group, while VE/VCO(2) slope did not show a significant increase (p > 0.05). CPET, GWI, and GCW did not increase significantly in the HCM group (p > 0.05), whereas GWW and PSD showed significant increases (p < 0.05). In contrast, in the control group, GWI and GCW increased significantly after CPET (p < 0.05), and no significant changes were observed in GWW and PSD (p > 0.05). Univariable linear regression analysis showed that MWT was correlated with NYHA class, GLS, PSD, GCW, GWW, Peak VO(2), and AT (p < 0.05). Multivariate linear regression analysis confirmed the independent associations of MWT with PSD, GCW, and GWW (p < 0.05). CONCLUSION: LV-PSL combined with CPET is effective in early detection of LV function and exercise endurance impairment in HCM patients, providing valuable information for clinical decision-making.