Electrogram Gated Radiofrequency Ablations with Duty Cycle Power Delivery Negates Effects of Ablation Catheter Motion
Background—Cardiac and respiratory movements cause catheter instability. Lateral catheter sliding over target endocardial surface can lead to poor tissue contact and unpredictable lesion formation. We describe a novel method of overcoming the effects of lateral catheter sliding movements by using an electrogram-gated pulsed power ablation.
Methods and Results—All ablations were performed on a thermochromic gel myocardial phantom. Ablation settings were randomized to Conventional (non-gated) 30W vs. EGM-Gated at 20% duty cycle (30W average power) at 0mm, 3mm, 6mm and 9mm lateral sliding distances. Forty-eight RF ablations were performed. Deeper lesions were created in EGM-Gated vs. Conventional ablations at 3mm (4.36 ± 0.08mm vs. 4.05 ± 0.17mm, p=0.009), 6mm (4.39 ± 0.10mm vs. 3.44 ± 0.15mm, p<0.001) and 9mm (4.41 ± 0.06mm vs. 2.94 ± 0.16mm, p<<0.001) sliding distances. EGM-Gated ablations created consistent lesions at a quicker rate of growth in depth compared to Conventional ablations (p<0.001).
Conclusions—(1) Lesion depth decreases and length increases in Conventional ablations with greater degrees of lateral catheter movements; (2) EGM-Gated pulsed RF delivery negated the effects from lateral catheter movement by creating consistently deeper lesions irrespective of the degree of catheter movement; and (3) Target lesion depths were reached significantly faster in EGM-Gated than Conventional ablations.
- electrogram gating
- duty cycle pulsed energy delivery
- radiofrequency ablation
- cardiac motion
- respiratory movements
- multimodality imaging
- imaging agent
- Received September 30, 2013.
- Revision received June 30, 2014.
- Accepted July 7, 2014.