Figure 2 Phenomena observed during diagnostic process of patient 2
2A: His bundle refractory period ventricular stimuli during tachycardia either reset or terminated tachycardia. 2B: RVA entrainment at different cycle lengths generated different fusion QRS morphologies, indicating ventricular myocardium took part in the reentry. 2C: EGM at successful ablation target and fluoroscopy showed the successful ablation target at the triangle of Koch. 2D: Sketch map of the mechanism in different situations. EGM=electrogram