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 .