Improved detection and analysis of sensed and paced events in dual chamberpacemakers with extended memory function - A prospective multicenter trialin 626 patients

Patients and Methods: This prospective study analyzed the incidence of atri al arrhythmias in a population of 626 patients in 173 medical centers of el even European countries and Japan with indication for a dual chamber pacema ker system. The accuracy of the new Automatic Interpretation for Diagnosis Assistance (AIDA) program which is included in Chorus pacemakers was evalua ted and the AIDA analysis was compared to and proven with Holter monitoring . Data stored in the pacemakers' memories for the first 24 hours (D1) were compared with simultaneously recorded 24-hour surface electrocardiograms, a nd data stored over the following 28 days (D28) were era mined against repo rted intercurrent symptoms. Results: At D1, atrial arrhythmias were detected by AIDA in 60 of 626 patie nts (12%), consisting of atrial fibrillation (n = 29), atrial flutter (n = 4), and miscellaneous arrhythmias (n = 17), and closely corroborated by Hol ter monitoring (sensitivity 93.7%, specificity 94.9%) At D28, 149 of 386 pa tients (49%) had had episodes of automatic mode switch prompted by atrial a rrhythmias. Symptoms were reported by 81 patients (54%), 92 (62%) had no hi stories of atrial arrhythmias, and 57 patients (38%) were neither symptomat ic nor had histories of atrial arrhythmias. An inverse relationship was fou nd between the number of atrial paced events a nd the occurrence of atrial arrhythmias (p < 0.001). A history of atrial arrhythmias and older age were associated with a higher risk of atrial arrhythmias (p < 0.05). In contras t, gender, hypertension, concomitant heart disease, or type of atrial lead fixation system were not related with the occurrence of atrial arrhythmias. Conclusion: AIDA allowed to confirm, or disprove, the occurrence of atrial arrhythmias as a source of symptoms reported during long-term follow-up. It could also be used to examine the efficacy of antiarrhythmic therapy, and be of assistance when weighing the needs for anticoagulation in patients ex periencing asymptomatic atrial arrhythmias.