Effect of ablation on local activation intervals and dominant frequencies of fibrillation

Activation frequencies of tachyarrhythmias may guide production of high-quality ablation lesions. To examine this in rabbit ventricles, frequencies from bipolar potentials adjacent to a continuous and transmural lesion were analyzed with a time-domain algorithm and FFT. Time-domain analysis produced greater variability among frequencies compared with dominant frequencies from the FFT. With either time-domain or FFT, frequency distributions were different after vs. before ablation. Means of frequencies had equal probability to increase or decrease, while standard deviations decreased after production of a continuous and transmural lesion. Thus, both the time-domain method and FFTs indicate reduced variation of activation frequencies by ablation.