The value of endomyocardial biopsies in myocarditis and dilated cardiomyopathy.

Since the introduction of the bioptome in 1962, examination of fresh endomyocardial tissue has been undertaken progressively in many centres despite the misgivings of some investigators. In my own experience, I have examined biopsies from 3225 patients, of whom 1978 were suspected to have dilated cardiomyopathy. Of these patients, 549 showed evidence of myocarditis. Categorization into active (acute), resolving (healing) and resolved (healed) stages is important because of therapeutic implications. It is concluded that endomyocardial biopsies are of immense value in dilated cardiomyopathy where the relationship with myocarditis has become established. Even though in many cases only non-specific features are found, biopsy excludes those conditions that can result in a hypertrophied, dilated heart. Biopsy also forms the baseline for further investigations, such as virological, immunological, morphometric analyses and distinction from alcohol effects, all of which have thrown light on the pathogenetic mechanism of dilated cardiomyopathy.