Abstract
Introduction: Ventricular fibrillation ECG is characterized by the
presence of irregular QRS complexes, with variable morphology, amplitude
and frequency. Aims: Analyze the electrocardiographic characteristic of
induced sustained VF (ISVF) . Methods: The 12 lead ECG of ISVF was
analyzed in 8 patients with coronary artery disease (CAD) and 7 with
Brugada Syndrome (BS). The ECG was divided into triggers and two
tachysystolic and sinusoidal phases, based on Wiggers’ stages. Results:
Triggers: Four QRS morphologies: similar to stimulated (IR); LBBB with
superior axis (SA) (suggesting origin in moderate band of the right
ventricle (MB); RBBB with superior left axis (SLA) (suggesting origin in
posteromedial papillary muscle (PPM) predominant in CAD; and LBBB with
inferior axis (IA) (suggesting origin in RVOT) predominant in BS.
Tachysystolic stage: there is a predominant morphology with RBBB and SA
in CAD; and morphologies with LBBB and IA in BS. Sinusoidal stage:
Complexes of small amplitude with notches appeared in SVF, but not in
non-sustained VF. Conclusions: The ECG at the onset and tachysystolic
stage of ISVF shows morphologies which may be related to the activation
of MB, PPM and RVOT. The notches could be a predictor of SVF .