on December 7, 2008
Published online before print December 7, 2008, doi: 10.1161/CIRCEP.107.737882
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Original Article |
Absence of pathognomonic or inflammatory patterns in cardiac biopsies of Brugada syndrome
1 Hospital of the University of Münster, Münster, Germany;
2 University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
3 Hospital of the University of Münster and University of Münster, Münster, Germany;
4 Marienhospital Osnabrück, Osnabrück, Germany
http://herzgenetik.klinikum.uni-muenster.de/
5 E-mail: heart{at}uni-muenster.de
Background—Brugada syndrome (BrS) is characterized by the presence of coved ST-segment elevations in the right precordial leads (so-called type I ECG) and additional clinical features. Caused by cardiac ion channel gene mutations, BrS may be associated with ventricular and atrial conduction disturbances as well as ventricular fibrillation. Recent studies have discussed whether BrS is merely a primary electrical disorder or whether inflammatory and/or other histopathologic abnormalities in the right ventricle (RV)
Methods and Results—We retrospectively analyzed BrS biopsy samples from 21 unrelated patients for histopathologic abnormalities (hypertrophy, fibrosis, inflammation, fatty tissue) together with the patients' clinical, genetic, and imaging data. Eleven patients (52%) had normal RV imaging (by angiography and/or echocardiography and/or cardiac magnetic resonance imaging). Results of myocardial biopsies were normal in 3 patients (14%) and revealed mostly moderate abnormalities in the others. Four patients (19%) had predominant fatty tissue in the RV myocardium. Using immunohistochemistry and conventional tissue staining, we could not detect inflammatory tissue changes, an observation compatible with the clinical absence of signs for myocarditis.
Conclusions—Imaging and histopathologic evaluation may detect moderate but uncharacteristic cardiac abnormalities in BrS patients. None of the patients had arrhythmogenic right-ventricular cardiomyopathy or overt myocarditis. Only in a small subset did predominant histopathologic abnormalities in the biopsy samples of the RV outflow tract occur that could provide a link to the ECG phenotype. A variety of mechanisms, including genetic and structural RV alterations, may underlie the Brugada ECG phenotype.
Key Words: arrhythmia • cardiomyopathy • genetics • pathology • patients
Author contributions: Sven Zumhagen and Tilmann Spieker contributed equally to this work.
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