Transmural left atrial roofline block using rescue cryoballoon ablation after unsuccessful radiofrequency ablation

Figures

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  Figure 1. Voltage and activation maps after pulmonary vein isolation and linear ablations. (A) Voltage map during distal coronary sinus (CS) pacing. The purple and gray colors represent voltage amplitudes of >0.5 mV and <0.05 mV, respectively. (B) Atrial electrograms recorded by the grid catheter on the left atrial posterior wall (LAPW). (C) Activation map during distal CS pacing. A centrifugal pattern was observed in the LAPW with the earliest activation site (yellow arrows) below the roofline. This suggests that epicardial propagation via an epicardial bundle crossed the roofline into the LAPW endocardium. Note that the activation propagation did not cross the floorline into the LAPW, indicating that the floorline block was completed. ABL = ablation catheter; RA = right atrium.

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  Figure 2. Voltage and activation maps after selective endocardial left atrial posterior wall (LAPW) isolation. (A) Voltage map during distal coronary sinus (CS) pacing. The purple and gray colors represent voltage amplitudes of >0.5 mV and <0.05 mV, respectively. The green tag indicates the ablated site at the earliest activation site. (B) Residual epicardial atrial electrograms (red arrowheads) recorded by the grid catheter on the LAPW. (C) Activation map during ablation catheter (ABL) pacing from the LAPW. The epicardial electrograms in the LAPW could be captured at a pacing output of 20 V at 2.0 ms. Note that the activation propagated across the roofline and broke out above the roofline but not above the floor line. RA = right atrium.

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  Figure 3. Catheter position and epicardial electrograms on the left atrial posterior wall (LAPW) during cryoballoon ablation. (A) Relationship between the cryoballoon and grid catheter in the left anterior oblique (top) and right anterior oblique (bottom) fluoroscopic views. A1 and D1 indicate the positions of the corresponding electrodes of the grid catheter. (B) Epicardial electrograms (red arrowheads) recorded by the grid catheter on the LAPW during distal coronary sinus (CS) pacing. Before freezing, the interval from pacing to epicardial electrograms on the LAPW was 130 ms. After 60 seconds of freezing, the interval was gradually prolonged. After 130 seconds of freezing, epicardial electrograms were eliminated, indicating successful transmural roofline block and LAPW isolation. HRA = high right atrium.