Addressing verapamil-sensitive idiopathic left ventricular tachycardia via catheter ablation targeting Purkinje potential on a false tendon: Rationale for using a high-resolution ablation catheter with distal-tip microelectrodes

Figures

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  Figure 1. The 12-lead ECGs. A: Sinus rhythm. B: Clinical VT. Cycle length: 390 ms; right bundle branch block pattern; axis −94°; QRS duration: 116 ms. ECG = electrocardiogram; VT = ventricular tachycardia.

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  Figure 2. Mapping during VT. A: The DECANAV catheter is positioned on the left ventricular septum alongside the left posterior fascicle through a transaortic approach. Dull sequential P1 potentials preceding the QRS onset by 40 ms were observed from the base to the apex, accomplished by sharp retrograde P2 potentials. B: When DECANAV was adjusted from the septum to a slightly lateral position, sharp P1 potentials were detected. DECANAV identifies sharper P1 potentials because of its proximity to a false tendon near the left ventricular septum. LAO = left anterior oblique; RAO = right anterior oblique; VT = ventricular tachycardia.

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  Figure 3. Successful ablation site. The microelectrodes detected the P1 potentials (arrows) exclusively, with no potential observed on the standard electrode of the ablation catheter. The image illustrates the QDOT MICRO catheter oriented perpendicular to the false tendon (P1 potential). The microelectrodes could detect P1 potentials using the transseptal approach, whereas conventional electrodes could not. The first RF application site elicited a response that terminated VT. LAO = left anterior oblique; RAO = right anterior oblique; Red tags = radiofrequency energy application sites through the transseptal approach; VT = ventricular tachycardia.

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  Supplementary Figure S1. Entrainment pacing from the P1 site Ventricular entrainment pacing for VT performed from the distal electrode of the DECANAV catheter at the site detecting P1 potentials showed minimal fusion and a post-pacing interval that matched the tachycardia cycle length.