Electrophysiological characteristics and long-term outcome of substrate-based catheter ablation for left posterior fascicular ventricular tachycardia targeting fragmented antegrade Purkinje potentials during sinus rhythm

Figure 1. Distribution of FAPs. The examples of distribution of FAPs including the proximal segment of posterior septal LV (A), middle segment (B), and distal segment (C). FAP, fragmented antegrade Purkinje potential; LAF, left anterior fascicle; LPF, left posterior fascicle; LV, left ventricle.

Figure 2. Morphology of single FAP. The FAP displayed a continuous multicomponent fragmented electrogram (A) and a fragmented, split, and uncoupled electrogram (B). FAP, fragmented antegrade Purkinje potential.

Figure 3. Example of entrainment from the FAP region during the LPF-VT in patient 12 with a tachycardia cycle length of 272 ms. (A) Selective capture of P2 was achieved during entrainment from the FAP region at pacing cycle length of 260 ms, and surface ECG demonstrated a concealed fusion of QRS morphology. The postpacing interval of P2 was almost equal to cycle length of LPF-VT. (B) P1 was selectively captured during entrainment from the FAP region at pacing cycle length of 250 ms. The surface ECG represented a concealed fusion of QRS morphology. The post-pacing interval of P1 was slightly longer than cycle length of LPF-VT. ECG, electrocardiogram; FAP, fragmented antegrade Purkinje potential; LPF-VT, left posterior fascicular ventricular tachycardia.

Figure 4. Successful ablation targeting FAPs during sinus rhythm in patient 5. (A) Note that an area with FAP was located within the posterior Purkinje fibre network and successful ablation was achieved by targeting FAPs. (B and C). The radiographic images of RAO 30°and LAO 45° showed the catheter positions. The ablation catheter was located at the posterior septal LV. (D and E). The FAPs were recorded before ablation and FAPs were eliminated after ablation. ABL, ablation catheter; CS, coronary sinus; FAP, fragmented antegrade Purkinje potential; HBE, His bundle electrogram; LAO, left anterior oblique; LV, left ventricle; RAO, right anterior oblique; RV, right ventricle.