Histopathological Aspects of Myocarditis with Special Reference to Mumps, Cytomegalovirus Infection and the Role of Endomyocardial Biopsy

Abstract

Myocarditis has been defined as “an inflammatory process of the heart muscle due to known or unknown causes, excluding atherosclerosis of the coronary arteries”, which may or may not be associated with inflammation elsewhere in the body” [21]. This definition is probably agreeable to most. For practical purposes, however, it is often difficult to establish morphologically whether or not certain structural changes are of an inflammatory (infectious) origin. Ischaemic heart disease must be excluded, which is not always easy or clear-cut; and what about the flabby, enlarged heart without significant cell infiltration at histological examination and for which an aetiological explanation cannot be traced? Is it caused by excessive alcohol consumption? Is it a sequel of myocarditis or the aftermath of exposition to toxic agents in the environment? What really constitutes the disease known as “dilated (congestive) cardiomyopathy”?

For help with this study we wish to express our sincere gratitude to Dr. H. Egeblad, Copenhagen, Denmark, Dr. F. Waagstein, Gothenburg, Sweden, and Prof. S. Olsen and Dr. E. Spencer, Aarhus, Denmark. In particular we want to thank Dr. E.G.J. Olsen and Dr. P. Richardson, London, who taught us cardiac pathology and the biopsy procedure