Utility of Simultaneous Biatrial Atrial Anti-Tachycardia Pacing for the Termination of Atrial Fibrillation during Catheter Ablation of Atrial Fibrillation

Figures

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  Figure 8. Three possible hypotheses for the mechanisms of AF termination. (A) Multi-wavelet reentry theory; Pacing stimulations collide the dominant circuit of a small reentrant circuit, and the balance of a multi-reentry collapses. The AF becomes unstable and cannot sustain, resulting in eventual termination. (B) Mother Rotor theory; Pacing stimuli block a main pathway of the mother rotor, preventing it from sustaining, resulting in eventual termination. CS = coronary sinus.

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  Figure 9. Three possible hypotheses for the mechanisms of AF termination. Leading circle theory; The presence of an excitable gap is well known for maintenance of AF. Pacing stimuli entrain and fill the excitable gaps of tachycardia, affecting the refractory period. Eventually, AF is unable to sustain itself and thus terminates slowly. CS = coronary sinus.

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  Figure 1. Pacing protocol of this study. AF = atrial fibrillation; CS = coronary sinus; CL = cycle length; HRA = high right atrium; Th = therapy.

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  Figure 2. Case 1. Burst pacing was attempted from the right atrial appendage, and AF was terminated after 4.5 s. In this case, 8/20 pacing impulses captured the RA (arrows), resulting in slowing of AF CL prior to AF termination. AF = atrial fibrillation; CL = cycle length; CS = coronary sinus; RAA = right atrial appendage; PAF = paroxysmal AF; S = stimulation: TA = tricuspid annulus.

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  Figure 3. Case 2. AF was terminated by simultaneous biatrial high-rate straight pacing from CS and HRA. Pacing captured the CS or HRA on alternately beats (red arrows), and AF organized into a more stable tachycardia. In the continuous wavelet transform analysis, red lines prolonged after pacing. The most powerful pseudo frequency (= mean dominant frequency) is colored red. AF = atrial fibrillation; CL = cycle length; CS = coronary sinus; HRA = high right atrium; PAF = paroxysmal AF; St = stimulation; TA = tricuspid annulus.

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  Figure 4. Case 3. AF resulted in organized tachycardia after simultaneous A-ATP from CS and HRA and terminated directly by decremental pacing. In the continuous wavelet transform analysis, red line prolonged after A-ATP. AF = atrial fibrillation; CS = coronary sinus; PAF = paroxysmal AF; HRA = high right atrium; St = stimulation.

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  Figure 5. Mean AF CL at baseline and post A-ATP. AF = atrial fibrillation; A-ATP = atrial anti-tachycardia pacing; CL = cycle length.

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  Figure 6. Baseline mean coefficient of variation at CS and HRA. AF = atrial fibrillation; Cs = coronary sinus; HRA = high right atrium.

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  Figure 7. A representative case involving a 60-year-old man with symptomatic PAF undergoing ablation which hypothesizes one mechanism of AF termination. During simultaneous biatrial straight pacing from the CS and HRA, 1/20 pacing impulses captured the HRA and 4/20 pacing impulses captured the CS (right blue arrows). However, the atrial activation sequences across both the HRA and CS catheters became reversed: At both CS and HRA catheters, the activation sequence changed from “distal to proximal” to “proximal to distal” after A-ATP (red arrows) before termination of AF. AF = atrial fibrillation; CL = cycle length; CS = coronary sinus; HRA = high right atrium; PAF = paroxysmal AF; S = stimulation.