title: Atrioventricular conduction after alcohol septal ablation for obstructive hypertrophic cardiomyopathy.
abstract: OBJECTIVE
  Lesion of the atrioventricular conduction system is a well known adverse effect of alcohol septal ablation (ASA) in patients with obstructive hypertrophic cardiomyopathy (HCM). We assessed the atrioventricular conduction at long-term follow-up after ASA.
  
  
  METHODS
  In patients with a pacemaker implanted for high-grade atrioventricular block after ASA, the atrioventricular conduction was assessed prospectively by ECGs and 48-h Holter recordings. In the remaining patients, the atrioventricular conduction was analysed retrospectively for comparison.
  
  
  RESULTS
  A total of 24 (28%) of 87 patients with obstructive HCM without a pacemaker at baseline had a pacemaker implanted due to high-grade atrioventricular block after ASA. Ten of these patients were not available for follow-up. Holter recordings in the remaining 14 patients revealed normalized atrioventricular conduction in 6 patients 6.2 years (range 2.1-9.4) after ASA. Patients with high-grade atrioventricular block at follow-up had longer PR intervals at baseline [205 ms (200-230)] than the rest of the cohort [180 ms (140-200), P = 0.004] and a higher incidence of acute complete heart block (63 vs. 15%; P = 0.007) during ASA. A PR interval of at least 200 ms at baseline was associated with higher prevalence of high-grade atrioventricular block at follow-up (30 vs. 2%; P = 0.0013). The incidence of late-onset complete heart block was 1.5% per year after ASA.
  
  
  CONCLUSIONS
  We found normalized atrioventricular conduction at long-term follow-up, suggesting recovery in 6 of 14 patients with a pacemaker implanted in relation to ASA. Permanent atrioventricular conduction abnormalities were associated with baseline PR intervals of at least 200 ms and acute persistent complete heart block during ASA.
authors.affiliation: aDepartment of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet & The University of Copenhagen bDepartment of Cardiology, Roskilde Sygehus, Roskilde, Denmark.
authors.forename: Anna
authors.initials: A
authors.lastname: Axelsson
authors.forename: Kristina
authors.initials: K
authors.lastname: Weibring
authors.forename: Ole
authors.initials: O
authors.lastname: Havndrup
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbæk
authors.forename: Erik
authors.initials: E
authors.lastname: Jørgensen
authors.forename: Steffen
authors.initials: S
authors.lastname: Helqvist
authors.forename: Kasper
authors.initials: K
authors.lastname: Iversen
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.forename: Henning
authors.initials: H
authors.lastname: Bundgaard
authors.forename: Morten Kvistholm
authors.initials: MK
authors.lastname: Jensen
mesh_terms: D055011:Ablation Techniques / Q000009:adverse effects* / Q000379:methods; D000368:Aged; D054537:Atrioventricular Block / Q000209:etiology / Q000503:physiopathology; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology / Q000601:surgery*; D004562:Electrocardiography / Q000379:methods; D000431:Ethanol; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011446:Prospective Studies
chemical_list: D000431:Ethanol