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.
Subject(s)
Cardiomyopathy, Dilated/pathology , Heart Ventricles/physiopathology , Hypertension, Pulmonary/physiopathology , Adult , Aged , Cardiac Catheterization/methods , Cardiomyopathy, Dilated/diagnostic imaging , Female , Heart Ventricles/diagnostic imaging , Hemodynamics , Humans , Hypertension, Pulmonary/diagnostic imaging , Magnetic Resonance Imaging , Male , Middle Aged , Muscles/diagnostic imaging , Muscles/pathology , RadiographyABSTRACT
OBJECTIVES: The aim of the present study was to assess the feasibility and safety of target-directed sampling of right ventricular (RV) endomyocardial biopsies (EMB) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). BACKGROUND: EMB is an integral part of the diagnostic evaluation of ARVC. Due to safety concerns, EMB are often obtained from the RV septum, which is usually spared from characteristic alterations. At our institution, EMB in ARVC patients were sampled target-directed from predilection areas and areas with abnormal contraction. METHODS: Under fluoroscopic guidance, 3,777 EMB samples from 6 different RV sites were obtained in 482 patients who were evaluated for unclear cardiomyopathy (n = 280; 58%), assumed myocarditis (n = 59; 12%), or unexplained ventricular tachyarrhythmias (n = 143; 30%). Complication rates were compared with those from exclusively septal EMB procedures (n = 2,321) in 271 patients after heart transplantation (HTx). RESULTS: Overall, no procedure-related deaths or sustained ventricular tachyarrhythmias occurred. A pericardial effusion was reported in 6 of 161 patients with the final diagnosis of ARVC (3.7%) needing no further intervention in all but 1 patient (0.6%) who required pericardiocentesis. Among the non-ARVC patients (n = 321), the incidence of a minor pericardial effusion (3.9%) and cardiac tamponade (2.2%) was comparable to that in ARVC (p = NS) but was higher when compared with HTx (p < 0.001). A transient complete atrioventricular block occurred in 1 of 321 non-ARVC (0.3%) and 2 of 271 HTx patients (0.1%). CONCLUSIONS: Multisite target-directed EMB sampling in ARVC is a safe procedure when performed by experienced interventionalists. The procedure-related complication rates were low and comparable to those in other cardiomyopathies.
