High-degree atrioventricular block during anti-arrhythmic drug treatment: use of a pacemaker with a bradycardia-detection algorithm to study the time course after drug withdrawal

• Published in: Europace (London, England) England), 2007-03, Vol.9 (3), p.186-191
• Main Authors: Kennebäck, Göran, Tabrizi, Fariborz, Lindell, Peter, Nordlander, Rolf
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Algorithms; Anti-Arrhythmia Agents - administration & dosage; Anti-Arrhythmia Agents - adverse effects; Bradycardia - etiology; Bradycardia - therapy; Female; Follow-Up Studies; Heart Block - etiology; Heart Block - therapy; Humans; Male; Medicin och hälsovetenskap; Middle Aged; Pacemaker, Artificial; Recurrence; Withholding Treatment
• ISSN: 1099-5129; 1532-2092
• DOI: 10.1093/europace/eul185

Aim This study examines the recurrence of high-degree atrioventricular block (AVB) during a follow-up period of 2 years in patients with restored AV node function after antiarrhythmic drug withdrawal at implantation of a pacemaker. Methods Nine men and eight women (77 ± 7 years) taking antiarrhythmic drugs (beta-receptor blockers in 15) and presenting with high-degree AVB were followed for 2 years after being taken off drugs upon receiving a permanent pacemaker with special bradycardia detection software. Results At inclusion, surface ECG identified two subsets of patients: a QRS duration < 120 ms (n = 5) and those with a QRS duration ≥120 ms (n = 12). During the 2-year follow-up, progression to high-degree AVB occurred in these groups: 1/5 (20%) and 9/12 (75%) P < 0.05. Six patients had to be restarted on drugs, mostly beta-receptor blockers, due to atrial tachyarrhythmias: 3/5 and 3/12. In total, 16 patients (94%) either developed high-degree AVB needing pacing or atrial tachyarrhythmias requiring drug treatment. Conclusion Patients on beta-receptor blocking drugs and QRS width ≥120 ms developing high-degree AVB should be recommended a pacemaker without further investigation or observation.