Cardiovascular magnetic resonance assessment of human myocarditis: a comparison to histology and molecular pathology.
BACKGROUND
Myocarditis can occasionally lead to sudden death and may progress to dilated cardiomyopathy in up to 10% of patients. Because the initial onset is difficult to recognize clinically and the diagnostic tools available are unsatisfactory, new strategies to diagnose myocarditis are needed.


RESULTS
Cardiovascular MR imaging (CMR) was performed in 32 patients who were diagnosed with myocarditis by clinical criteria. To determine whether CMR visualizes areas of active myocarditis, endomyocardial biopsy was taken from the region of contrast enhancement and submitted to histopathologic analysis. Follow-up was performed 3 month later. Contrast enhancement was present in 28 patients (88%) and was usually seen with one or several foci in the myocardium. Foci were most frequently located in the lateral free wall. In the 21 patients in whom biopsy was obtained from the region of contrast enhancement, histopathologic analysis revealed active myocarditis in 19 patients (parvovirus B19, n=12; human herpes virus type 6 [HHV 6], n=5). Conversely, in the remaining 11 patients, in whom biopsy could not be taken from the region of contrast enhancement, active myocarditis was found in one case only (HHV6). At follow-up, the area of contrast enhancement decreased from 9+/-11% to 3+/-4% of left ventricular mass as the left ventricular ejection fraction improved from 47+/-19% to 60+/-10%.


CONCLUSIONS
Contrast enhancement is a frequent finding in the clinical setting of suspected myocarditis and is associated with active inflammation defined by histopathology. Myocarditis occurs predominantly in the lateral free wall. Contrast CMR is a valuable tool for the evaluation and monitoring of inflammatory heart disease.
Mahrholdt
Heiko
H
Division of Cardiology, Robert Bosch Medical Center, Stuttgart, Germany. heiko.mahrholdt@rbk.de
Goedecke
Christine
C
Wagner
Anja
A
Meinhardt
Gabriel
G
Athanasiadis
Anasthasios
A
Vogelsberg
Holger
H
Fritz
Peter
P
Klingel
Karin
K
Kandolf
Reinhard
R
Sechtem
Udo
U
D000328:Adult; D000368:Aged; D001706:Biopsy; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis; D003287:Contrast Media; D018450:Disease Progression; D004562:Electrocardiography; D004699:Endocardium / Q000473:pathology; D005260:Female; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000473:pathology; D015654:Herpesvirus 6, Human / Q000302:isolation & purification; D006801:Humans; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D010322:Parvoviridae Infections / Q000175:diagnosis / Q000473:pathology / Q000821:virology; D016732:Parvovirus B19, Human / Q000302:isolation & purification; D019349:Roseolovirus Infections / Q000175:diagnosis / Q000473:pathology / Q000821:virology; D016037:Single-Blind Method; D013318:Stroke Volume
D003287:Contrast Media; D019786:Gadolinium DTPA