Atypical pacemaker-mediated tachycardia from the atrial channel: What is the mechanism? (original) (raw)
A 79-year-old woman with history of hypertension, dyslipidemia, obesity, bulbar stroke , and paroxysmal atrial fibrillation was evaluated for an abrupt syncope. Echocardiogram showed no abnormalities, and Holter monitoring showed sinus arrhythmia with right bundle branch block (RBBB) and signs of sick sinus syndrome due to significant pauses. A dual-chamber pacemaker was implanted without complications (ventricular electrode in the right ventricular apex and atrial electrode at the high right atrial appendage). Pacemaker settings were DDDR mode, basic rate 65 bpm, maximum sensor rate 110 bpm, maximum tracking rate 150 bpm, and dynamic AV interval of maximum 280/minimum KEYWORDS Pacemaker-mediated tachycardia; electrodes dislodgement ABBREVIATIONS ECG ϭ electrocardiogram; PMT ϭ pacemaker-mediated tachycardia; RBBB ϭ right bundle branch block (Heart Rhythm 2011;8:636 -638)
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