Myocarditis: Unresolved issues in diagnosis and treatment

Abstract

Summary: Myocarditis is an enigmatic disease. Lymphocytic myocarditis is most commonly viral in origin. Considerable evidence suggests that myocardial damage is due to an immune-mediated mechanism rather than to direct effects of the virus itself. The presentation is variable, ranging from a clinically inapparent or relatively benign illness to acute progressive heart failure and death. Although examination of the endomyocardial biopsy specimen is the "gold standard" for the diagnosis of myocarditis there are problems with this technique, relating particularly to sampling error and histologic interpretation. Considerable evidence, both animal and human, suggests that a link between viral myocarditis and dilated cardiomyopathy does exist. There is a rational basis for the use of immunosuppressive therapy in myocarditis. Although many favorable responses have been reported with the use of these agents, the results of more definitive studies are awaited to determine the role of immunosuppressive therapy in myocarditis more clearly. Recommendations for the practical management of patients with myocarditis are made. Whenever possible, patients with this diagnosis should be entered into the ongoing NIH trial.

Histologic and In Situ Viral Findings in the Myocardium in Cases of Sudden, Unexpected Death

“…Our protocol has been previously published (8,10,12). In brief, after deparaffinization, sections were incubated with CD45 or CD68 (DAKO, Carpinteria, CA).…”

“…The members of the genus Enterovirus (family Picornaviridae) are the most commonly implicated in viral myocarditis (2, 6, 8 -9). Coxsackie B virus may account for nearly 50% of cases of documented viral myocarditis (8). Many other viruses are associated with viral myocarditis, including Coxsackie A, influenza A, cytomegalovirus, and adenovirus, as well as other viruses (6,8).…”

“…In cases of sudden, unexpected death, serology is usually not available, and viral cultures have relatively low sensitivity, especially in the autopsy setting (8). In situ hybridization analyses for DNA viruses, which are associated with high copy number, show both high sensitivity and specificity, as documented in cases of cytomegalovirus and adenovirus-associated myocarditis (12)(13)(14).…”

CXCL10 Inhibits Viral Replication Through Recruitment of Natural Killer Cells in Coxsackievirus B3-Induced Myocarditis

“…Key Words: cardiomyocytes Ⅲ chemokine CXCL 10 Ⅲ coxsackievirus Ⅲ myocarditis Ⅲ natural killer cells C oxsackievirus (CV)B3 has been recognized as the predominant cause of viral myocarditis in humans. 1 This disease is composed of three distinct stages including viremic injury, immune infiltration, and reclamation. 2 Earlier studies have suggested that mechanisms of viral myocarditis include direct myocyte injury by CVB3 and subsequent immune-mediated damage of the heart.…”

“…1 This disease is composed of three distinct stages including viremic injury, immune infiltration, and reclamation. 2 Earlier studies have suggested that mechanisms of viral myocarditis include direct myocyte injury by CVB3 and subsequent immune-mediated damage of the heart.…”