Abstract 17935: Optimal Parameters for the Ablation of Myocardial Tissue With Pulsed Electric Fields
Background: RF ablation of atrial tissue has a significant recurrence rate, requires the sacrifice of substantial amounts of atrial tissue, and tissue heating can have serious complications (e.g. esophageal fistulae). Electroporation with pulsed electric fields (PEFs) is a new alternative to ablate tissue. We test the ablation efficacy of PEFs with different characteristics.
Methods: We isolated New Zealand rabbit hearts (n=8), placed them in a Langendorff setup, and used optical mapping to establish a control activation map during myocardial surface stimulation. Then we repeatedly inserted two shock electrodes, spaced 3-7 mm apart, into the LV (through the entire wall) and applied a PEF (between 2-20 kV/cm, 1-1000 pulses at 1-100 Hz). We used propidium iodide stains and sectioning to characterize the three-dimensional geometry of the ablated volume.
Results: Using nsPEFs, we are able to create nonconducting lesions. After a lesion has been created, the activation map shows a clear line of block (see Panel A). The geometry of the ablated volume is smooth, and uniform throughout the wall (see Panel B). The width of the lesions can be controlled via the electrode spacing and the shock parameters (see Table C). Ablation with nsPEF does not significantly heat tissue, so thermal damage to neighboring tissues is not a concern.
Conclusions: Ablation with nanosecond pulsed electric fields is a promising alternative to RF ablation of AF, that is capable of producing non-conducting lesions and gives better control of the scar geometry than RF ablation.
- © 2013 by American Heart Association, Inc.