title: Management of patients with drug-induced atrioventricular block.
abstract: OBJECTIVE
  To identify the frequency of atrioventricular (AV) conduction improvement after discontinuation of the culprit drug in patients with AV block.
  
  
  BACKGROUND
  AV blockers are considered as reversible causes of AV block that do not require pacemaker (PM) implantation. However, controversial reports declared that a major part of these drug-induced AV blocks are persistent or recurrent.
  
  
  METHODS
  Of 668 consecutive patients with symptomatic type II second- or third-degree AV block, 2:1 AV block, atrial fibrillation, and bradyarrhythmia, 108 patients (62 patients enrolled prospectively) using AV blockers without myocardial infarction, electrolyte abnormalities, digitalis toxicity, and vasovagal syncope were enrolled into the present study. The level of AV block (AV-nodal or infranodal) was defined according to electrocardiographic characteristics.
  
  
  RESULTS
  The most frequent culprit medications were β-blockers followed by digoxin. Drug discontinuation was followed by resolution of AV block in 72% of cases, whereas spontaneous resolution of AV block occurred in only 6.6% of patients who had AV block in the absence of medications. However, 27% of patients with improved AV conduction experienced a recurrence of AV block despite discontinuation of the culprit drug. Twenty-one of 24 carvedilol-induced AV blocks resolved after discontinuation of the drug and never recurred, whereas 24 of 36 metoprolol-induced AV blocks persisted or recurred. A digoxin-induced AV block usually improved (28 of 39) after withdrawal of the drug. Roughly half of the patients with drug-induced AV block underwent permanent PM implantation.
  
  
  CONCLUSIONS
  Drug-induced AV block is a serious disease that requires a permanent PM for almost half of the patients.
authors.affiliation: Department of Cardiology, Siyami Ersek Cardiovascular and Thoracic Surgery Center, Istanbul, Turkey. damirbeko@yahoo.com
authors.forename: Damirbek
authors.initials: D
authors.lastname: Osmonov
authors.forename: Izzet
authors.initials: I
authors.lastname: Erdinler
authors.forename: Kazim Serhan
authors.initials: KS
authors.lastname: Ozcan
authors.forename: Servet
authors.initials: S
authors.lastname: Altay
authors.forename: Ceyhan
authors.initials: C
authors.lastname: Turkkan
authors.forename: Ersin
authors.initials: E
authors.lastname: Yildirim
authors.forename: Hakan
authors.initials: H
authors.lastname: Hasdemir
authors.forename: Ahmet Taha
authors.initials: AT
authors.lastname: Alper
authors.forename: Nazmiye
authors.initials: N
authors.lastname: Cakmak
authors.forename: Seckin
authors.initials: S
authors.lastname: Satilmis
authors.forename: Kadir
authors.initials: K
authors.lastname: Gurkan
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects*; D000368:Aged; D054537:Atrioventricular Block / Q000139:chemically induced* / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data*; D015995:Prevalence; D012307:Risk Factors; D016896:Treatment Outcome; D014421:Turkey / Q000453:epidemiology
chemical_list: D000319:Adrenergic beta-Antagonists