Detection of atrial fibrillation via pacemaker threshold scanning

Atrial fibrillation (AF) is the most commonly occurring arrhythmia, often present in addition to more serious arrhythmias. When a patient with an ICD has an episode of atrial fibrillation, the resulting irregular and rapid ventricular rate leads to false identification of a tachycardia. Automatic detection of atrial fibrillation could therefore improve ICD and pacemaker specificity, as well as lead to devices specifically for AF. The major obstacle preventing automatic AF detection is the failure of the sensing threshold to produce consistent rate estimates without over/under-sensing. The authors propose a new algorithm based on the hypothesis that: in sinus rhythm (SR), rate measurements are constant over a wide range of sensing thresholds; whereas in AF, rate measurements are a highly dependent function of threshold