Auto reference vector: a novel method for mapping atrial fibrillation

Figures

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  Figure 1. Auto reference Vector mapping configuration. (A) The omnipolar activation vector is calculated using the B2 and C2 electrodes as reference. (B) Reference electrode detection is set to maximum amplitude with auto-sensitivity. (C) The median AF cycle length is 180 ms. The cycle length tolerance is set to ±50 ms, and the window of interest is defined as ±30 ms from the reference annotation.

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  Figure 2. Disorganized activation pattern (CASE 1). ARV mapping (MAP1) of left atrium in a de novo case revealed a chaotic activation pattern. A repeat map (Map 2), performed immediately after Map 1, demonstrated poor reproducibility of vector directions. Blue dots indicate the reference point on the left atrial posterior wall, consistent across both maps.

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  Figure 3. Organized activation pattern and reproducibility of focal sources. (CASE 6) (A) ARV mapping of the left atrium in a case with high reproducibility. AF spontaneously terminated due to mechanical stimulation from the HD Grid catheter near the location of the orange dots during Map 1 acquisition. AF was reinduced, and Map 2 was then created. Both maps demonstrated highly concordant ARV directions with a consistent collision pattern near the mid-posterior wall. Focal sources were repeatedly identified at the same location near the bottom of the previously isolated right inferior pulmonary vein (orange dots in Map 1 and green dot in Map 2). (B) The Focal vector score (FVS) values were 4 and 3 for Map 1 and Map 2, respectively. Both focal sources exhibited a QS pattern in unipolar electrograms.

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  Central Illustration. Mapping AF with the auto reference vector (ARV). ARV mapping enables categorization of AF activation patterns into organized and disorganized types. Prior ablation and longer AF cycle lengths are associated with increased AF organization. ARV mapping also facilitates confirmation of conduction block lines, identification of PVI gaps, and localization of focal sources acting as AF drivers. Ablation of these focal sources was associated with suppression of AT/AF. AF, atrial fibrillation; AT, atrial tachycardia; LA, left atrium; PVI, pulmonary vein isolation; CL, cycle length.

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  Figure 4. Representative case for ARV focal sources identified in both left and right atria (CASE 22). (A) The intracardiac electrograms showing AF with median cycle lengths of 140 ms and 132 ms measured at SVC and CS, respectively (HD grid positioned in SVC). (B) LA map showed an organized activation pattern with two focal sources near the LA roof and one near the LAA (yellow circles). (C) Others regions of the LA were passively activated, with vectors colliding at the posterior wall. (D) RA map showed passive conduction from Bachmann bundle (yellow circle). (E) Another focal source was identified in the anterolateral aspect of distal SVC (black star). A white line indicates the collision of activation vectors originating from SVC and those passively conducted from LA. (F) Ablation of three LA sources and one SVC source using a circular PFA catheter resulted in immediate termination of AF. The SVC source (yellow circle) was located 52 mm distal to the sinus node (cyan circle). Isoproterenol administration and repeated atrial decremental pacing failed to induce AT/AF afterwards. TCL, tachycardia cycle length; SVC, superior vena cava; CS, coronary sinus; LAA, left atrial appendage; PFA,…

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  Figure 5. Kaplan–Meier curve showing atrial tachyarrhythmia–free survival in patients who underwent ablation of ARV-identified focal sources.