Triggers:
Spontaneous Ventricular fibrillation (VF) is initiated by premature ventricular contraction (PVC) originating in the right ventricle outflow tract (RVOT) , Purkinje from left or right ventricle1,3,5. It is not known whether these structures also participate in the onset of induced VF. In our study, the morphologies found suggest activation of specific structures: LBBB with late transition and superior axis (suggesting origin in moderate band of the right ventricle); RBBB with superior left axis (suggesting origin in posteromedial papillary muscle PPM) and LBBB with inferior axis (suggesting origin in RVOT). Similar complexes of stimulated QRS (IR) would be due to local myocardial reentry12. In Brugada VF the most frequent triggers correspond to morphologies suggestive of RVOT, often showing moderator band morphologies in cases of induced VF and, exceptionally, in spontaneous VF analyzed in articles; this could be interpreted as the moderating band behaving as a bridge to the RVOT of the extrastimuli applied from the apex of the RV .