Differentiation of constrictive pericarditis and restrictive cardiomyopathy using digitized echocardiography

Constrictive pericarditis and restrictive cardiomyopathy are difficult to distinguish at the bedside and occasionally at routine cardiac catheterization. Left ventricular diastolic function was studied by computer analysis of digitized M-mode echocardiograms in four patients with constrictive disease and three with restrictive disease, and the data were compared with those of normal subjects. The respective distinguishing echographic features of constrictive pericarditis and restrictive cardiomyopathy were as follows: the major filling period of the left ventricle was 78 +/- 9% of normal versus 128 +/- 4% (p less than 0.01), minimal left ventricular dimension to peak filling interval was 50 +/- 10 versus 110 ms (p less than 0.05) and the maximal rate of left ventricular posterior wall thinning was -4.9 versus -2.3 seconds-1 (p less than 0.05). This preliminary study suggests that it may be possible to accurately diagnose the two disease entities using this technique at the bedside and to avoid cardiac catheterization.