Epicardial confirmation of conduction block during thoracoscopic surgery for atrial fibrillation - a hybrid surgical-electrophysiological approach

Abstract

Background: Totally thoracoscopic epicardial pulmonary vein ablation is an emerging treatment of atrial fibrillation (AF). A hybrid surgical-electrophysiological procedure with periprocedural confirmation of conduction block might reduce recurrences of AF or atrial tachycardia and improve surgical success. Methods and results: We report our joint surgical-electrophysiological approach for confirmation of conduction block across pulmonary vein ablation lines and those compartmentalizing the left atrium during totally thoracoscopic surgery. A diagnostic electrophysiology (EP) catheter positioned under the left atrium is used as reference and a custom-made multi-electrode for recording. Determination of conduction block across the pulmonary vein (PV) ablation lines requires measurement of activation time differences of milliseconds. Second, a stable reference electrogram to which to relate local activation time is required. Third, the recording electrode terminals and the inter-electrode distance should be small to prevent recording of far field activity and to allow recording of very small electrograms. We confirm entry and exit block and determine conduction block across linear ablation lines with differential pacing. Conclusion: A joint surgical-electrophysiological protocol for confirmation of conduction block across PV isolation lines and left atrial ablation lines is feasible and might prevent recurrences and further improve the success of minimally invasive surgery for AF.

Key words::

• Atrial fibrillation
• ablation
• thoracoscopic surgery
• radiofrequency ablation
• electrophysiology
• pulmonary veins

Acknowledgements

Dr De Groot is supported by the Netherlands Heart Foundation, grant 2009T021. Dr Jackman is a consultant for Atricure and Biosense Webster. The authors thank Wim L. ter Smitte and Carel Kools for manufacturing and maintaining the recording electrodes.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.