Abstract 16447: Bipolar Electrogram Signatures of Therapeutic Interest During Human Ventricular Fibrillation
BACKGROUND: Rotor theory states that high frequency periodic sources called rotors are responsible for maintenance of ventricular fibrillation (VF). If strategies are to be developed for treatment of VF based on this theory then a clinician would need to identify the bipolar electrogram signatures of rotors and the location of these rotors in near real-time.
OBJECTIVE: To identify the bipolar signature of rotors and quantify the relationship between the location of rotors with bipolar electrogram signatures during human ventricular fibrillation.
METHODS: VF experiments were conducted in 7 isolated human hearts using Langendorff setup. Hardwired simultaneous 112 unipolar and 112 bipolar electrograms were acquired during VF from epicardium. 2D scar, dominant frequency, and phase maps were constructed for each of the VF episodes. Rotors were identified using 2D phase maps. The immediate vicinity of the spatial locations of rotors (limited to 6 electrodes around the core of the rotor) was analyzed to identify if any of the seven different bipolar electrogram patterns were observed. These seven different electrograms are shown in Figure 1 and they were chosen based on the prominence of occurrence of these patterns over the studied database of VF episodes.
RESULTS: The results suggest that all the 18 rotors co-localize with the boundaries of scar and frequency variations and 44% of the rotors occur at locations where the bipolar electrogram demonstrate continuous activities. In none of the vicinity of the analyzed rotors we observed high frequency activities in the bipolar electrograms.
CONCLUSION: The rotors co-localize to scar and frequency boundaries and reflect continuous activities on the bipolar electrograms. In a clinical setting these bipolar signatures may serve as a marker to the locations of interests for modulating VF
- © 2011 by American Heart Association, Inc.