Figure 2
(A) Intracardiac electrogram during ventricular tachycardia with a cycle length of 325 ms originating from the Para-Hisian region. Prolonged and fractionated ventricular potentials preceding the QRS onset by 56 ms were recorded within the noncoronary cusp, corresponding to the opposite side of the para-Hisian region.
(B) Intracardiac electrogram during ventricular overdrive pacing at a cycle length of 300 ms from the noncoronary cusp during the ventricular tachycardia. The arrows indicate the artifact of the pacing stimulus that was not captured. I, II, V1, V3, V5 = surface electrogram; HRA = high right atrium; His d and His p = distal and proximal His bundle region; NCC d and NCC p = distal and proximal noncoronary cusp; RV d and RV p = distal and proximal right ventricle; S = pacing. The numbers indicate the cycle lengths in ms.