Morphologic spectrum of primary restrictive cardiomyopathy.
A restrictive hemodynamic profile with left ventricular (LV) end-diastolic volume < 100 ml/m2 and LV end-diastolic pressure > 18 mm Hg, in the absence of endomyocardial, pericardial, and specific cardiomyopathy, is a peculiar feature of primary restrictive cardiomyopathy. From 1985 to 1994, 7 hearts of patients who met the above hemodynamic criteria and underwent endomyocardial biopsy because of heart failure, were studied through gross (5 cardiectomies and 2 autopsies), histologic, and electron microscopic investigations. Ages ranged from 9 to 48 years (mean age 29 +/- 13). Four patients (57%) had a positive family history: 2 for hypertrophic and 2 for restrictive cardiomyopathy. Three patterns were identified in the 7 hearts: (1) pure restrictive form in 4 cases with mass/volume ratio 1.2 +/- 0.5 g/ml, ejection fraction 58 +/- 5%, LV end-diastolic volume 67.5 +/- 12.6 ml/m2, LV end-diastolic pressure 26.7 +/- 3.5 mm Hg; (2) hypertrophic-restrictive form in 2 cases with mass/volume ratio 1.5 +/- 0.07 g/ml, ejection fraction 62 +/- 1%, LV end-diastolic volume 69 +/- 10 ml/m2, LV end-diastolic pressure 30 +/- 7 mm Hg; and (3) mildly dilated restrictive form in 1 case with mass/volume ratio 0.9 g/ml, ejection fraction 25%, LV end-diastolic volume 98 ml/m2, LV end-diastolic pressure 40 mm Hg. Histology and electron microscopy disclosed myocardial and myofibrillar disarray and endoperimysial interstitial fibrosis in each pattern. The familial forms suggest the presence of a genetic abnormality. Primary restrictive cardiomyopathy may present with or without hypertrophy and shares similar microscopic pictures with hypertrophic cardiomyopathy. The 2 entities may represent a different phenotypic expression of the same genetic disease.
Angelini
A
A
Department of Pathology, University of Padua Medical School, Italy.
Calzolari
V
V
Thiene
G
G
Boffa
G M
GM
Valente
M
M
Daliento
L
L
Basso
C
C
Calabrese
F
F
Razzolini
R
R
Livi
U
U
Chioin
R
R
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002313:Cardiomyopathy, Restrictive / Q000473:pathology* / Q000503:physiopathology*; D002648:Child; D017023:Coronary Angiography; D004699:Endocardium / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006352:Heart Ventricles / Q000473:pathology / Q000648:ultrastructure; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged