Abstract 11025: Insertable Cardiac Monitors Reveal Progression of 1st Degree AV-block to Higher Grade Block Requiring Pacemaker Implant
Introduction: In the past, 1st degree AV-block has generally been considered a benign condition. A few recent studies have shown that 1st degree AV-block is associated with an increased risk for heart failure, pacemaker (IPG) implantation, and death. We investigated the outcomes of patients who received an insertable cardiac monitor (ICM) (Medtronic Reveal XT®) within the scope of the INSIGHT XT study and had 1st degree AV-block at baseline.
Methods: The observational, international, multicenter INSIGHT XT study prospectively enrolled 1003 patients implanted with an ICM for arrhythmia diagnosis, irrespective of the clinical indication. This analysis includes 37 patients (3.7%) who had documented 1st degree AV-block at enrollment. Patients with known concurrent higher grade block at enrollment were excluded.
Results: The indication for ICM implantation was syncope or pre-syncope in 54.1%, cryptogenic stroke in 18.9%, AF with rhythm control intervention in 21.6%, and unexplained palpitations or symptoms in 5.4%. The mean age was 68±14 years and 75.7% were male. Concurrent bundle branch block (BBB) was present in 8.1%. The median follow-up time was 12.2 months (IQR: 3.9-15.9). Fifteen patients (40.5%) received an IPG during the follow-up, and in 93.3% of the cases the implant was needed to treat a progression of the conduction disease. In addition, one patient died due to sinus arrest 86 days after enrollment; one patient developed transient 3rd degree AV block but did not receive an IPG.
Conclusions: The ICM revealed progression of 1st degree AV-block to a higher grade block warranting an IPG in 40.5% patients. This finding supports the conclusion that 1st degree AV-block is not benign in all patients. Further studies may reveal patient subgroups which are at high risk for developing higher grade AV block and may warrant a preventive IPG implantation.
Author Disclosures: T. Lewalter: Honoraria; Modest; Medtronic, St. Jude, Biotronik. Consultant/Advisory Board; Modest; Medtronic, St. Jude, Biotronik. G. Rieger: Employment; Significant; Medtronic Plc. L. Mangoni: Employment; Significant; Medtronic Italia S.p.A.
- © 2015 by American Heart Association, Inc.