A rare case of pacemaker mediated tachycardia caused by intrinsic conduction search function of a dual chamber pacemaker.

Pacemaker-mediated tachycardia (PMT) is a well-described cause of tachyarrhythmia in patients with dual chamber pacemakers (Barold, 1991 [1]). PMT is usually caused by common triggers including premature ventricular or atrial complexes (Alasti et al., 2018 [2]). However, PMT can also be triggered by other uncommon mechanisms. Intrinsic conduction search function is a feature available in some dual chamber permanent pacemakers that periodically looks for intrinsic conduction by gradually prolonging the preprogrammed AV delay in an attempt to minimize ventricular pacing (Calvi et al., 2017; Pakarinen and Toivonen, 2013 [3,4]). Here, we report a rare case of PMT triggered by intrinsic conduction search function.