Critical analysis of endomyocardial biopsies from patients suspected of having cardiomyopathy. I: Morphological and morphometric aspects
Baandrup, U.; Olsen, E.G.
British Heart Journal 45(5): 475-486
ISSN/ISBN: 0007-0769 PMID: 7195268 Accession: 005068026
Biopsies  obtained by bioptome from 201 patients with suspected cardiomyopathy were analyzed morphologically, semiquantitatively, quantitatively and statistically to ascertain whether or not histological examination provided a measurable pattern characterizing the different forms of cardiomyopathy. Whether or not morphometry increases the diagnostic reliability was studied. Hearts from 29 cases (10 female and 19 male) who died as a result of road traffic accidents or other extracardiac causes were sampled, selecting specimens from sites usually biopsied during life. Of these biopsies, 16.1% were of such poor quality that morphological categorization was not possible. The mean size of biopsies was 0.79 mm2. On average, 1.38 mm2 of tissue was available per patient. The histological descriptions were grouped in 8 entities; morphometric analysis of the endocardium, myocardium and interstitium resulted in a more accurate evaluation of the morphological changes. Muscle fiber diameter showed distinct variance between several morphological groups, particularly between normal and pathological groupings and between right and left sided ventricular samples. The applied scoring system included the histological HOCM (hypertrophic cardiomyopathy) index which separated clearly this type of cardiomyopathy from other disorders. Small foci of chronic inflammatory cells were seen in 25% of the biopsies and did not indicate myocarditis. The possible existence of small vessel disease was not confirmed. Morphometric data permitted distinction between several histological groups but this did not apply to individual patients in view of a considerable degree of overlap of the pathological changes. Combining the various morphological features and applying measurements failed to establish a definite pattern for congestive cardiomyopathy (COCM) and alcoholic heart muscle disease could not be separated from COCM. Semiquantitative and morphometric methods are mandatory, define more accurately the morphological changes, and to provide the basis for additional biochemical, immunological and virological analysis.