Cytomegalovirus infection of the heart is common in patients with fatal myocarditis.
BACKGROUND
Although enteroviruses and adenoviruses are considered to be the leading causes of the usually mild clinical myocarditis, little is known about the etiology of severe or fatal myocarditis.


METHODS
We collected all available clinical records and myocardial autopsy samples for patients who had myocarditis recorded as the underlying cause of death in Finland during the period of 1970-1998. Findings for all available patients (20 men and 20 women; median age, 49 years) with myocarditis that fulfilled the Dallas criteria and who had sufficient data were included in the study. Twelve subjects who had died accidentally served as control subjects. Polymerase chain reaction (PCR) and in situ hybridization assays were used for detection of viral genomes (adenovirus, cytomegalovirus, enterovirus, human herpesvirus 6, influenza A and B viruses, parvovirus B19, and rhinovirus) in heart samples.


RESULTS
Viral nucleic acids were found in the hearts of 17 patients (43%), including cytomegalovirus (15 patients), parvovirus B19 (4 patients), enterovirus (1 patient), and human herpesvirus 6 (1 patient). In 4 patients, cytomegalovirus DNA was found in addition to parvovirus B19 or enterovirus genomes. No adenoviruses, rhinoviruses, or influenza viruses were detected in this study of fatal myocarditis. In 67% of the patients for whom PCR was positive for cytomegalovirus, in situ hybridization revealed viral DNA in cardiomyocytes. Only 1 of these patients was immunocompromised. In the control group, only human herpesvirus 6 (1 subject) and parvovirus B19 (1 subject) DNA were detected.


CONCLUSIONS
In this population-based study, cytomegalovirus was found to be the most common specific finding in immunocompetent patients with fatal myocarditis. This may have important clinical implications for the treatment of severe acute myocarditis.
Kytö
Ville
V
Department of Anatomy, University of Turku, Turku, Finland. ville.kyto@utu.fi
Vuorinen
Tytti
T
Saukko
Pekka
P
Lautenschlager
Irmeli
I
Lignitz
Eberhard
E
Saraste
Antti
A
Voipio-Pulkki
Liisa-Maria
LM
D000293:Adolescent; D000328:Adult; D000368:Aged; D001344:Autopsy; D002423:Cause of Death; D002675:Child, Preschool; D003586:Cytomegalovirus Infections / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D004279:DNA, Viral / Q000302:isolation & purification; D005260:Female; D005387:Finland / Q000453:epidemiology; D006321:Heart / Q000821:virology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000150:complications* / Q000401:mortality* / Q000821:virology; D012189:Retrospective Studies
D004279:DNA, Viral