Polarization-Sensitive Optical Coherence Tomography (PSOCT) for identifying and analyzing gaps in lesion lines during ex vivo simulated radiofrequency ablation procedure

Atrial fibrillation (AF) is the most common arrhythmia worldwide. An increasingly common treatment option is catheter ablation. During this procedure, the electrophysiologist steers a catheter into the left atrium and ablates a lesion fence around common sources of ectopic signals. This blocks arrhythmogenic tissue from initiating an erroneous heartbeat. Technological advancements in this maturing procedure have made ablations more widespread and effective for patients, but there is still a need to improve long term efficacy of the procedure. The national rate of recurrent AF after an ablation is 20% to 40% and this is almost universally due to reconnection via poor lesion quality. With current catheter feedback available to clinicians, it is difficult to assess whether a lesion line will remain durable or heal to initiate recurrent AF. We have previously shown that polarization-sensitive optical coherence tomography (PSOCT) can monitor lesion formation in vivo during an ablation procedure. This feedback at the catheter tip may help clinicians assess lesion quality by measuring tissue changes. To further understand the technology's utility and limitations, we are conducting experiments to characterize PSOCT detection of gaps between lesions. Lesion gaps are a common failure mode when AF recurrence is caused by reconnection. We ablate left atrial swine myocardium ex vivo and collect PSOCT images to compare with histology and identify the detection limits of small lesion gaps. Using PSOCT at the catheter tip to detect small gaps in lesion lines could help clinicians reduce recurrence by decreasing opportunities for reconnection.