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

AbstractDiastolic 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 < 0.01 between 20% and 50%, p < 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 < 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 < 0.01) or in normal subjects (173 ± 32 ms, p < 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 < 0.05) or in normal subjects (24 ± 9%, p < 0.01). Peak filling rate in stroke volumes/s, but not in end-diastolic volumes/s, was significantly greater in patients with pericardial constriction (5.09 ± 0.97) than in those with restrictive cardiomyopathy (3.52 ± 0.43, p < 0.01) or in normal subjects (3.98 ± 0.70, p < 0.05).The pattern of left ventricular filling by radionuclide angiography helps differentiate restrictive cardiomyopathy from pericardial constriction