Pasquale Crea

An 80‐year‐old woman received a dual chamber pacemaker (Boston Scientific Accolade MRI DR) for pre‐syncopal episodes associated with transient II‐degree atrioventricular block type 1 and 2:1, recorded in 24‐h Holter monitoring. Due to residual AV conduction with I‐degree AV block, the pacemaker was set with the RYTHMIQ® algorithm, in order to reduce inappropriate ventricular pacing. A month later the patient started to complain of severe asthenia and bradycardia (46‐48 bpm). Telemetry‐supported pacemaker control revealed III‐degree AV block with junctional escape rhythm, unmasking missed switch of RYTHMIQ® algorithm.