Catheter Ablation in Persistent AF, the Evolution towards a More Pragmatic Strategy

Figure 1. ECGi mapping approach. A 252 body-surface electrode array, combined with thoracic CT imaging (A) allows for the depiction of virtual cardiac potentials on the epicardial surface (B) and can identify re-entrant (B, right top panel) and focal activities (B, right bottom panel) from activation maps generated from unipolar electrograms. The AFACART study used this technique to identify driver sites in both atria which were targeted for ablation (C) with the endpoint of converting complex, fractionated signals into simple, discrete signals (D). R1-R6 indicate regions where CFAEs were identified.

Figure 2. Strategies for substrate ablation in persistent AF. (A) Roof and mitral isthmus lines created using optimized RF lesions as per the ALINE protocol. (B) Fluoroscopic image of contrast injection of the coronary sinus with the Vein of Marshall indicated by the white arrow. (C) Voltage map post ethanolization of the Vein of Marshall demonstrating the resultant area of low voltage and additional endocardial lesions at the mitral annulus performed to achieve mitral isthmus block. CS = coronary sinus.

Figure 3. Proposed ablation strategy for persistent AF. Patients with no adverse features for recurrent AF (left atrial dilatation, fibrosis, etc.) and/or evidence of self-terminating AF on continuous monitoring undergo PVI only while those with adverse features or non-self-terminating AF undergo PVI plus linear ablation at the roof and mitral isthmus facilitated by Vein of Marshall ethanolization. VoM = Vein of Marshall (ethanolization).