An atrial fibrillation suppression algorithm encourages angina

An 86-year-old man presented to hospital with non-ST elevation myocardial infarction, having had a dual-chamber permanent pacemaker inserted 1 year prior for mixed sinus and atrio-ventricular node disease (St Jude Zephyr XL, model 5826). A rhythm strip at admission showed tracked atrial ectopics followed by ventricular pacing at a rate of 120 bpm (Figure 1, top panel). During admission he continued to experience rapid ventricular pacing and angina until his pacemaker's atrial fibrillation (AF) suppression algorithm Dynamic Atrial Overdrive® pacing, was disabled. As a result the patient's pacing rates dropped to 60–70 bpm with DDDR and then DDIR 60–120 programming (Figure 1, bottom panel). His chest pain resolved dramatically, he subsequently declined a coronary angiogram and was discharged home on medical therapy with excellent control of his angina. In this case the AF suppression algorithm Dynamic Atrial Overdrive® pacing, lead to a hospital admission for acute coronary syndrome. Increased atrial ectopy at the time of the patient's admission drove his atrial pacing rate up, increasing his cardiac workload and causing angina. Deactivation of this feature successfully resolved the patient's symptoms. This case demonstrates the need for careful physician decision making when deciding which patients are appropriate for these additional pacemaker capabilities. The full-length version of this report can be viewed at: http://www.escardio.org/communities/EHRA/publications/ep-case-reports/Documents/atrial-fibrillation.pdf