Right ventricular dysfunction in hypertrophic cardiomyopathy as evidenced by the myocardial performance index

Background: Left ventricular function in hypertrophic cardiomyopathy (HCM) has been extensively studied, whereas right ventricular function is much less explored. The myocardial performance index (MPI) has been shown to be useful in functional assessment of both ventricles. Furthermore, right ventricular MPI was found to be of predictive value in heart failure due to dilated cardiomyopathy and ischemic heart disease. The aim of this study was, therefore, to evaluate the right ventricular MPI in patients with HCM. Methods: Fifty patients with HCM and 250 healthy controls were studied by conventional Doppler echocardiography and Doppler tissue imaging. Results: Patients showed increased global, 0.48 (0.15) vs. 0.21 (0.14), and regional, 0.71 (0.23) vs. 0.55 (0.17), right ventricular MPI, as compared to controls, p < 0.001. Tricuspid annular plane systolic excursion and peak myocardial systolic velocities were also reduced. Patients with dyspnoea had increased global right ventricular MPI (0.53 vs. 0.36, p < 0.05) as compared to those without dyspnoea. Conclusion: In the present study, patients with HCM showed evidence of both global and regional right ventricular dysfunction. Previous studies of the right ventricle in HCM have only shown evidence of diastolic dysfunction, contrary to our results, showing impairment of both systolic and diastolic function. This study suggests that HCM should not only be regarded as an isolated disease of the left ventricle, but rather as a biventricular disease. The predictive value of our findings in HCM needs to be assessed in a separate study with special reference to those with and without dyspnoea.