The Role of Right Ventriculo-Arterial Coupling in Symptoms Presentation of Patients With Hypertrophic Cardiomyopathy

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 NYHA classification, and echocardiographic measurements of left ventricle systolic and diastolic function have been conducted. The echocardiographic assessment of right vetriculo-arterial coupling (RVAC) has been made by calculating the tricuspid annular peak systolic tissue Doppler velocity (TASV)/estimated RV systolic pressure (RVSP) ratio. Results: Almost half, 22 (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” compared to the “asymptomatic” group. TASV was lower in the “symptomatic” compared to the asymptomatic group (11±1cm/sex vs. 13±2cm/sec, 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” compared with the “asymptomatic” group (0.32±0.09 vs. 0.46±0.11, p<0.001). Conclusion: A low RVAC (as TASV/RVSP ratio) value could represent an echocardiographic marker of right ventricular-arterial uncoupling in patients with HCM and may impaired functional status.