Background;
Brugada Syndrome (BS) is a disease known to cause ventricular fibrillation (VF) with structurally normal heart. Gene mutation (i.e. SCN5A) has been proposed to be related to the development of BS and VF. However, the pathophysiological mechanism associated with VF development without SCN5A mutation has not been studied yet. Oxidative stress is a common disorder that is related to many heart diseases. We have previously demonstrated that oxidative stress is closely linked to the arrhythmic development. Accordingly, we examined 4-hydroxy-2-nonenal (HNE) modified protein, which is a common mediator of oxidative stress in the myocardium, and VF episodes in patients with BS.
Methods;
We collected sixty-eight BS patients that underwent right ventricular endomyocardial biopsy (66 males, 2 female; mean age 49.0±11.6 years old). VF was documented in 11 and SCN5A mutation was detected in 14 patients. Biopsy samples were processed for histology [Masson’s trichrome staining for fibrosis, immuno staining for CD45, CD68, and HNE modified protein]. All results from histology were compared with VF episodes. We also performed the analysis in VF patients with (n=14) or without SCN5A mutations (n=54).
Results:
HNE positive area was significantly larger in VF patients [VF(+): 16.3±10.5, VF(−): 9.3±5.7%: P=0.029]. All other parameters (fibrosis area, CD45, and CD68) were not different between the groups. In multivariable analysis, HNE positive area was most important risk factor of VF development in patients without SCN5A mutation (P=0.004).
Conclusions
; These data suggested that oxidative stress is associated with VF development in BS patients, especially in patients without SCN5A mutation.
Incidence of patients at high risk of sudden death among patients referred for the suspicion of a brugada-syndrome: a prospective study in 35 consecutive patients with Brugada-like ECG changes
