Determinants of Right Ventricular Muscle Mass in Idiopathic Dilated Cardiomyopathy: Impact of Left Ventricular Muscle Mass and Pulmonary Hypertension

Abstract

Introduction: Although chronic pulmonary hypertension and right ventricular (RV) function carry important functional and prognostic implications in idiopathic dilated cardiomyopathy (IDC), little information on RV muscle mass (RVMM) and its determinants has been published.Methods: Our study comprised thirty-five consecutive patients with IDC, left ventricular (LV) ejection fraction <40% and NYHA class ≥2. Hemodynamic data and parameters on LV and RV geometry were derived from right heart catheterisation and cardiac magnetic resonance imaging.Results: RVMM was normalized to body size using a common linear, body surface area based approach (RVMMI) and by an allometric index (RVMM-AI) incorporating adjustment for age, height and weight. Stepwise multiple regression analysis revealed that pulmonary artery pressure and left ventricular muscle mass were independent predictors of RVMM-AI. The interventricular mass ratio of RV and LV mass (IVRM) was closely related to RVMM (r = 0.79, p < 0.001) and total muscle mass (r = 0.39, p < 0.02). However, there was no significant relationship between LVMM and IVMR (r = 0.17, p = 0.32).Conclusion: Our data suggest that an increase in RV mass in IDC may be explained by two mechanisms: First, as a consequence of the myopathic process itself resulting in a balanced hypertrophy of both ventricles. Second, due to the chamber specific burden of pulmonary artery pressure rise, resulting in unbalanced RV hypertrophy.

A predictive model for dilated cardiomyopathy with pulmonary hypertension

“…However, should the PH-DCM continue, unfortunately, pulmonary endothelial dysfunction will occur, resulting in significant vasoconstriction and irreversible remodelling of the pulmonary vessels, which will lead to right ventricular stasis and hypertrophy, eventually resulting in tricuspid regurgitation (TR) and SM at the tricuspid area on auscultation. 10 As the right ventricle is much more sensitive to prolonged pressure overload, over time, the right heart can be irreversibly damaged, eventually resulting in heart failure. 14 Based on the pathological process of the development of DCM described above, it is suggested that SM at the apex and tricuspid area, which, respectively indicate the presence of MR and TR, are feasible factors for predicting PH probability in DCM patients.…”

“…Although RHC is the gold standard for PH diagnosis, it is relatively complicated, expensive and invasive and is associated with a number of complications. 10 Consequently, Doppler echocardiography is recommended by the ESC/ERS Guidelines as a tool for the detailed assessment of right heart haemodynamics, as it is considered a non‐invasive and widely available diagnostic instrument for PH‐DCM patients. 11 However, Doppler echocardiography could be technically demanding and often involves a significant cost; thus, the prediction of PH appears to be an impossible mission in some community hospitals with poorer methods of examination.…”

A Predictive Model for Dilated Cardiomyopathy With Pulmonary Hypertension

“…However, should the PH-DCM continue, unfortunately, pulmonary endothelial dysfunction will occur, resulting in signi cant vasoconstriction and irreversible remodelling of the pulmonary vessels, which will lead to right ventricular stasis and hypertrophy, eventually resulting in tricuspid regurgitation (TR) and SM at the tricuspid area on auscultation [10]. As the right ventricle is much more sensitive to prolonged pressure overload, over time, the right heart can be irreversibly damaged, eventually resulting in heart failure [15].…”

“…Although RHC is the gold standard for PH diagnosis, it is relatively complicated, expensive, and invasive and is associated with a number of complications [10]. Consequently, Doppler echocardiography is recommended by the ESC/ERS Guidelines as a tool for the detailed assessment of right heart haemodynamics, as it is considered a non-invasive and widely available diagnostic instrument for PH-DCM patients [11].…”

Electrocardiogram signs of right ventricular hypertrophy may help identify pulmonary hypertension in patients with dilated cardiomyopathy

“…Ultimately, right ventricular uncoupling to the demands of the pulmonary circulation leads to RV failure [10]. The previous study has suggested that an increase in RV mass in DCM not only associated with a consequence of the myopathic process itself but also burden of pulmonary artery pressure rise [11]. So the RV is the ultimate victim of these vascular processes [3].…”