Background: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy. The hallmark of HCM is myocardial fibrosis which contributes to heart failure, arrhythmias, and sudden cardiac death (SCD).
Objective: To identify the factors implicated in heart failure symptoms and functional capacity of patients with HCM.
Methods: In this cohort study, 43 patients with HCM were recruited. According to functional capacity and symptoms presentation, patients were categorized according to New York Heart Association (NYHA) classification, and echocardiographic measurements of left ventricle systolic and diastolic function were conducted. The echocardiographic assessment of right ventriculo-arterial coupling (RVAC) was made by calculating the tricuspid annular peak systolic tissue Doppler velocity (TASV)/estimated RV systolic pressure (RVSP) ratio.
Results: Almost half (51%) of our study population present symptoms of heart failure and were categorized as the symptomatic group-NYHA 2 or higher. Maximum LVOT gradient, RVSP, and the ratio of E/e' were higher in the symptomatic group compared with the asymptomatic group. TASV was lower in the symptomatic group compared with the asymptomatic group (11 ± 1 cm/s vs. 13 ± 2 cm/s, p = 0.04). However, there was no difference in other potentially influential factors, such as heart rate or systemic blood pressure. The SCD risk score does not differ between the two studied groups. The RVAC (estimated with the TASV/RVSP ratio) was lower in the symptomatic group compared with the asymptomatic group (0.32 ± 0.09 vs. 0.46 ± 0.11, p < 0.001).
Conclusion: A low RVAC (as estimated with TASV/RVSP ratio) value could represent an echocardiographic marker of right ventricular-arterial uncoupling in patients with HCM and impaired functional status.
Keywords: cardiomyopathies; heart failure; hypertrophic cardiomyopathy.