ABC | Volume 115, Nº1, Suplement, July 2020

Case Report Cruz et al. An Unusual Pacemaker-Induced Tachycardia Arq Bras Cardiol 2020; 115(1Suppl.1):14-17 Figure 1 – ECG after pacemaker implantation. Repetitive cycle of an atrial paced beat and an atrial intrinsic beat both followed by a ventricular intrinsic beat. Figure 2 – Reproduction of the intracardiac atrial and ventricular electrograms overlaying lead I of the presenting surface ECG. A: atrial channel. Ap: atrial paced event. Ar: atrial event sensed in the refractory period. V, ventricular channel. Vi, intrinsic ventricular event. Vp, ventricular paced event. 15