Pulmonary Vein Isolation Lesion Set Assessment During Radiofrequency Catheter Ablation for Atrial Fibrillation

Figures

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  Figure 1:. Recording from a circular mapping catheter showing overlap of far-field and near-field signals from the left atrium and pulmonary vein musculature, respectively. Adapted from: Tada H, Oral H, Greenstein R, Pelosi F Jr., Knight BP, Strickberger SA, Morady F. Differentiation of atrial and pulmonary vein potentials recorded circumferentially within pulmonary veins. J Cardiovasc Electrophysiol. 2002;13(2):118–123.

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  Figure 2:. Circular mapping catheter recordings from within the pulmonary veins (PVs). (a) Recording from left inferior PV while pacing from the distal coronary sinus (CS) and performing ablation. Entrance conduction is evident on the first beat but disappears by the second beat, suggesting acute PV isolation. (b) Recording from the left superior PV while pacing distal CS. Adenosine bolus reveals dormant PV reconnection consistent with incomplete ablation near lasso pole 3. (c) Pacing of the left superior PV causes an evoked response fused with the pacing artifact on lasso poles 3/4 and 4/5. Exit conduction is evident after the second paced beat. (d) PV isolation with exit block despite adenosine bolus. Pacing from the lasso catheter induces evoked responses on poles 6/7 and 7/8. Note atrioventricular block because of adenosine but continued dissociation between the evoked responses and CS atrial activation.

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  Figure 3:. Color projection of a voltage map onto a segmented and registered magnetic resonance imaging of the left atrium. This map represents endocardial peak-to-peak bipolar voltage (color scale from 0.3–1.5 mV, red-yellow-green-blue-purple) created with a high density 20 pole-mapping catheter (PentaRay®, Biosense Webster, Inc., Diamond Bar, CA, USA). It reveals gaps of incomplete ablation (arrows). Low voltage signals in the superior portion of the right inferior pulmonary vein in this image were determined to be far field.

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  Figure 4:. Acoustic radiation force impulse elastography (ARFIE) reveals regions of incomplete ablation. (a) Two views of a segmented and registered computed tomography scan. The intracardiac echocardiography imaging plane is seen projected on the sepal margin of the right inferior pulmonary vein (PV) antrum and yields the image in (b). Radiofrequency ablation (RFA) tags are marked in red, and the red arrows designate regions with intact conduction (noted on lasso recordings). (b) The ARFIE image demonstrating stiff ablated areas (blue) and soft un-ablated areas (red) corresponding with sites of incomplete ablation and PV connection. (c) A left atrial ARFIE image of the ligament of Marshall before ablation; the tissue was uniformly soft (appearing red) consistent with unablated tissue (left). After two RF pulses (see inset), the ARFIE image shows two discrete lesions that are incomplete (arrows). Adapted from: Bahnson TD, Eyerly SA, Hollender PJ, et al. Feasibility of near real-time lesion assessment during radiofrequency catheter ablation in humans using acoustic radiation force impulse imaging. J Cardiovasc Electrophysiol. 2014;25(12):1275–1283.