The relative atrial volume ratio and late gadolinium enhancement provide additive information to differentiate constrictive pericarditis from restrictive cardiomyopathy

Abstract Background The differentiation of constrictive pericarditis (CP) from restrictive cariomyopathy (RCM) is often difficult. This study sought to determine the clinical utility of cardiovascular magnetic resonance imaging (CMR) for differentiating both these disorders. Methods Twenty-three patients with surgically documented CP, 22 patients with RCM and 25 normal subjects were included in the study. CMR yielded information about cardiac morphology, function and tissue characteristics. The left (LA) and right atrial (RA) volume was calculated using the area-length method. The relative atrial volume ratio (RAR) was defined as the LA volume divided by RA volume. Receiver operating characteristic curve analysis was used to test the ability of different variables in differentiating CP from RCM. Results The maximal pericardial thickness in CP patients was significantly larger than in normal subjects and RCM patients. The RA volume index in RCM patients (90.5 ± 35.3 mL/m2) was significantly larger than in CP patients (71.4 ± 15.7 mL/m2, p = 0.006) and normal subjects (38.1 ± 9.0 mL/m2, p 2) and CP patients (105.6 ± 25.1 mL/m2) was significantly larger than in normal subjects (39.5 ± 9.5 mL/m2, p Conclusions CMR with LGE and RAR can facilitate differentiation of CP from RCM.