Since the first description of Brugada syndrome (BrS), there has been controversy about his association with structural abnormalities of the myocardium.

To identify an invariant histological substrate in patients with a definite BrS.

A BrT1 patient who had an autopsy after an episode of VF prompted us to perform a review of published case reports of autopsies and bi-ventricular histological samples to study patients with a spontaneous BrT1 who experienced VF and/or SCD and for whom there was no signs of an associated myocardial disease before the histological examinations.

Sixteen studies and cases reports were reviewed that included 127 patients; eight of these cases fulfilled the study criteria. In total, nine patients were evaluated in the present study (mean age 35.3±10.4 years, eight males, four autopsies, five bi-ventricular myocardial biopsies). Eight patients had undergone cardiac imaging and no abnormality was found. None of the four patients in the autopsy series presented with a normal heart and all four had significant left ventricular hypertrophy. Pathological examination was abnormal in all patients. An occult myocarditis was diagnosed histologically in six of the nine patients and seven had criteria for myocardial inflammation. Local myocardial PCR were positive for parvovirus B19 in three patients. Only one patient had criteria consistent with an arrhythmogenic cardiomyopathy.

Viral myocarditis and left ventricular hypertrophy appear to be recurrent findings in patients with Brugada syndrome who experience VF and/or SCD. In contrast to the classical definition of this disease, none of the BrS patients with detailed histologic investigations had a normal heart.