Differentiation of restrictive cardiomyopathy from pericardial constriction: assessment of diastolic function by radionuclide angiography.

Diastolic filling variables were studied in 12 patients with the hemodynamic features of constriction, of whom 5 had restrictive cardiomyopathy, 5 had pericardial constriction and 2 had combined pericardial constriction and restrictive cardiomyopathy. The values were compared with those in 10 normal subjects of comparable age. The filling fractions between 10% and 70% of the diastolic time interval were greater in patients with pericardial constriction than in those with restrictive cardiomyopathy (p less than 0.01 between 20% and 50%, p less than 0.05 at 10%, 60% and 70%), with no overlap. The filling fractions in patients with pericardial constriction were also greater than those in normal subjects between 10% and 60% of the diastolic time interval. The filling fraction was lower in patients with restrictive cardiomyopathy than in normal subjects at 40% of the diastolic time interval (p less than 0.05). The time to peak filling rate in patients with pericardial constriction was shorter (110 +/- 14 ms) than in those with restrictive cardiomyopathy (195 +/- 45 ms, p less than 0.01) or in normal subjects (173 +/- 32 ms, p less than 0.01). The percent of atrial contribution to left ventricular filling was higher in those with restrictive cardiomyopathy (45 +/- 17%) than in those with pericardial constriction (21 +/- 6%, p less than 0.05) or in normal subjects (24 +/- 9%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)