Activation intervals during electrically-induced ventricular fibrillation in pigs became longer and more regular as VF duration increased from 1-3 seconds (110±17 ms) to 10-12 seconds (115±15 ms).
Absolute Event Rate: 115% vs 110%
Previous studies suggest that the organization of epicardial activation patterns (EAP) during ventricular fibrillation (VF) changes over both time and space. To investigate whether organization of EAP changes during the first few seconds of electrically-induced VF, the authors recorded unipolar electrograms V(t) from 504 epicardial recording sites (21/spl times/24, 1 mm separation) during multiple runs of VF in three open-chest pigs. Activation intervals (temporal difference between local activation times defined by selecting dV/dt/sub max/ within 25 ms window) were determined at nine of the epicardial sites during 2 s segments of data taken 1, 5 and 10 s after VF induction. Activation intervals (mean/spl plusmn/SD) became longer and more regular as VF duration increased from 1-3 s (110/spl plusmn/17 ms) to 10-12 s (115/spl plusmn/15). The spatial distribution of SD over the mapped region tended to decrease over this same time period. These findings may have important implications related to therapeutic strategies which attempt to produce regional control of myocardial activation patterns during VF.
Chattipakorn et al. (Tue,) conducted a other in Ventricular fibrillation (n=3). Electrically-induced ventricular fibrillation vs. Early stage (1-3 s) was evaluated on Activation intervals. Activation intervals during electrically-induced ventricular fibrillation in pigs became longer and more regular as VF duration increased from 1-3 seconds (110±17 ms) to 10-12 seconds (115±15 ms).