Differentiation Between Restrictive Cardiomyopathy and Constrictive Pericarditis by Early Diastolic Doppler Myocardial Velocity Gradient at the Posterior Wall

BACKGROUND: The differential diagnosis between restrictive cardiomyopathy (RCM) and constrictive pericarditis (CP) is challenging and, despite combined information from different diagnostic tests, surgical exploration is often necessary. METHODS AND RESULTS: A group of 55 subjects (mean age, 63+/-11 years; 36 men and 19 women) were enrolled in the study; 15 had RCM, 10 had CP, and 30 were age-matched, normal controls. The diagnosis of RCM was supported by a biopsy; in the CP group, the diagnosis was confirmed either surgically or at autopsy. All patients underwent a transthoracic echocardiogram that included the assessment of Doppler myocardial velocity gradient (MVG), as measured from the left ventricular posterior wall during the predetermined phases of the cardiac cycle. MVG was lower (P<0.01) in RCM patients compared with both CP patients and normal controls during ventricular ejection (2. 8+/-1.2 versus 4.4+/-1.0 and 4.7+/-0.8 s(-1), respectively) and rapid ventricular filling (1.9+/-0.8 versus 8.7+/-1.7 and 3.7+/-1.4 s(-1), respectively). Additionally, during isovolumic relaxation, MVG was positive in RCM patients and negative in both CP patients and normal controls (0.7+/-0.4 versus -1.0+/-0.6 and -0.4+/-0.3 s(-1), respectively; P<0.01). During atrial contraction, MVG was similarly low (P<0.01) in both RCM and CP patients compared with normal controls (1.6+/-1.7 and 1.7+/-1.8 versus 3.8+/-0.9 s(-1), respectively). CONCLUSIONS: Doppler myocardial imaging-derived MVG, as measured from the left ventricular posterior wall in early diastole during both isovolumic relaxation and rapid ventricular filling, allows for the discrimination of RCM from CP.