A new diagnostic concept in cardiac pacing for evaluating the incidence ofatrial arrhythmias: Results of the AIDA study.

An international, prospective, multicentre trial (AIDA) was undertaken from October 1995 to March 1997. The object was to compare the diagnosis of atr ial arrhythmias (AA) by the automatic interpretation of the memory function s of dual chamber pacemakers with that of 24 hour Holter monitoring at day 1. The second objective was to assess the incidence and symptomatology of t he AA during follow-up at Day 28. In France, 226 patients implanted with Chorus,Chorus II and Chorus RM pacem akers were included in the study (148 men, 70.5 +/- 10.8 years) for the fol lowing indications : AVB (atrioventricular block)/bundle branch block (47.3 %), sinus mode dysfunction (10.2%), bradycardia-tachycardia syndrome (10.2% ), AVB + sinus node dysfunction + cardia-tachycardia syndrome (19.5%), othe r (2.2%). AA were documented in 34.5% of patients before implantation. Of the 226 patients analysed at Day 1, 23 (10.2%) had at least one episode of AA diagnosed simultaneously by Holter monitoring and the automatic inter pretation (AIDA). These AA were atrial fibrillation (15 patients), atrial f lutter (2 patients) and atrial tachycardia (6 patients). The sensitivity of the AIDA programme for detecting AA was 92% and the specificity 97%. Of th e 156 patients evaluated at Day 28, the programme diagnosed AA in 78 patien ts (50%), 34 of which (21.8%) were asymptomatic and without previously docu mented AA. The results of the AIDA study confirmed the excellent sensitivity and speci ficity of the memory functions of these cardiac pacemakers for analysis of AA. They seem to be very common during the follow-up of pacemaker-equipped patients. This new diagnostic concept will facilitate the programming and s tudy of the efficacy of antiarrhythmic therapy prescribed during long-term follow-up.