Novel dual-reference approach facilitates the activation mapping and catheter ablation of premature atrial complexes with non-pulmonary vein and non-superior vena cava origins

Figures

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  Figure 1. Flowchart of patient enrolment and procedures. AF, atrial fibrillation; AFL, atrial flutter; AT, atrial tachycardia; DRA, dual-reference approach; PAC, premature atrial complexes; PV, pulmonary vein; SRA, single-reference approach; SVC, superior vena cava.

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  Figure 2. Schematics of the SRA and the DRA. (A) When a PAC (circle) is firing, the CT of the pulses propagating from the origin to the proximal CS is CT1, while CT from the origin to LAA is CT2. The difference of CT between CT2 and CT1 is a constant (CT2 − CT1) during this targeted PACs. When performing the activation mapping, the electrograms of the reference catheter are fixed. The LAT of the mapping site preceding the fixed reference is identical with CT from the mapping site to the reference. (B) The SRA using proximal CS as the only reference. The CS catheter exhibits an identical proximal-to-distal activation sequence among targeted PACs, non-targeted PACs, and bumped ectopies. The bumped or non-targeted ectopies have earlier LAT1 than targeted PACs, forming a mistaken activation map. (C) The DRA using proximal CS and LAA catheters as references. The relative timing between LAT1 and LAT2 (LAT2 − LAT1) during PACs is identical with the constant (CT2 − CT1). The bumped or non-targeted ectopies might present earlier LAT1 than targeted PACs. However, the electrograms of the mapping catheter when placed at the bumped sites or at the origin of non-targeted PACs present different LAT2 −…

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  Figure 3. Representative case of PACs mapping using the SRA. (A) A bumped ectopy and (B) the targeted PACs. Tracings are 12-lead ECG (a) and intracardiac electrograms (b) recorded from the CS catheter (CS 1–10), a multipolar mapping catheter (penta 1–20), and an ablation catheter (MAP 1–4) in a patient with frequent PACs. Corresponding activation maps of right atrium before and after manual reannotation show on c and d, respectively. The CS catheter was set as the only timing reference. Noted that the P′ wave morphology and CS activation sequence were roughly identical between the bumped ectopy and the targeted PACs. Before the reannotation, two sites exhibited the equally earliest activation, i.e. the lateral wall (Ac) and 7 o’clock of tricuspid annulus (Bc), suggesting the presence of mistakenly collected points. After a time-consuming process of manual reannotation, the bumped points on the lateral wall were removed (Ad). The satisfactory target was therefore set at the 7 o’clock of tricuspid annulus (Bd). CRA, cranial; CS, coronary sinus; LAO, left anterior oblique; PA, posterior–anterior; PACs, premature atrial complexes.

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  Figure 4. Representative case of PACs mapping using the DRA. (A) Twelve-lead ECG of the targeted PACs. (B) Intracardiac electrograms of the targeted PACs before activation mapping. The CS catheter (CS 56) and the ablation catheter placed at LAA (MAP 12) were set as the timing references. The PentaRay catheter was placed away from the proximity of the endocardium to avoid bumping. The timing difference between CS 56 and MAP 12 during PACs was 52 ms, which was set as the constant for distinguishing the targeted PACs from bumped or non-targeted ectopies. (C) The electrograms of a bumped ectopy showed that the timing difference between CS 56 and MAP 12 was 16 ms, which is not equal to the constant (52 ms). Therefore, this bumped point was quickly distinguished and removed. (D) The electrograms of the targeted PACs showed that the timing difference between two references was equal to 52 ms. Noted the two potentials on MAP 12 were similar with those in (B), also confirming the targeted PACs. (E and F) After the target was determined at para-hisian region, the ablation catheter was retracted from LAA and used for ablation at right atrium. The LAT on MAP 12 preceding CS 56 was 65 ms. However, PACs…

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  Figure 5. Recurrence of atrial arrhythmias over time. Shown are Kaplan–Meier estimates of the freedom from recurrence of atrial arrhythmias, including frequent PACs (100/24 h, off antiarrhythmic drugs) and atrial tachyarrhythmias (including AF, AFL, and AT over 30 s), between 3 and 24 months after catheter ablation. Tick marks indicate censored data. CI, confidence interval; DRA, dual-reference approach; SRA, single-reference approach.