title: Role of implantable cardioverter defibrillator therapy in patients with acquired long QT syndrome: a long-term follow-up.
abstract: OBJECTIVE
  The use of implantable cardioverter defibrillators (ICD) in patients with torsade de pointes (TdP) and ventricular fibrillation in the presence of acquired long QT syndrome (aLQTS) is under debate, partly due to the fact that aLQTS is potentially reversible and currently no long-term follow-up data are available. We aimed to evaluate the long-term follow-up of patients with acquired long QT syndrome (aLQTS) who had received an implantable cardioverter defibrillator (ICD) for secondary prevention of sudden cardiac arrest (SCA).
  
  
  RESULTS
  Over a 10 year period, 43 patients with an ICD after survived cardiac arrest (SCA) due to an aLQTS were included [female n= 27 (63%); mean age 61 ± 16 years]. There was no clinical evidence for congenital LQTS (Schwartz score 1.25 ± 0.8). Structural heart disease was present in 29 patients (47%; ischaemic n= 13; dilated cardiomyopathy n= 9; mean EF 41%± 12). The most common proarrhythmic trigger happened to be antiarrhythmic drugs (n= 34; 79%). Other triggers included contrast agent (n= 1), haloperidol (n= 2), severe hypokalaemia (n= 2), drug abuse/alcohol (n= 2), and mere severe bradycardia (n= 2). Under trigger QTc interval measured 536 ± 58 vs. 438 ± 33 ms without trigger (P< 0.001). During a mean follow-up of 84 ± 55 months, appropriate shocks occurred in 19 patients (44%); inappropriate shocks in 13 patients (30%; only inappropriate n= 3). Appropriate shocks were almost as common in patients without as in those with structural heart disease (35 vs. 48%; P= 0.32). None of the patients were re-exposed to the initial trigger during the follow-up period. Beta-blocker medication did not prevent ICD shocks (12 of 19 vs. 11 of 24 on medication).
  
  
  CONCLUSIONS
  Appropriate ICD shocks are a common finding in patients with aLQTS and SCA irrespective of the underlying cause or structural heart disease. Thus, even in the presence of relevant acquired proarrhythmia ICD may be beneficial.
authors: Department of Cardiology and Angiology, Division of Experimental and Clinical Electrophysiology, University Hospital Münster, Münster, Germany. moennig@uni-muenster.de
authors: Gerold
authors: G
authors: Mönnig
authors: Julia
authors: J
authors: Köbe
authors: Andreas
authors: A
authors: Löher
authors: Kristina
authors: K
authors: Wasmer
authors: Peter
authors: P
authors: Milberg
authors: Stephan
authors: S
authors: Zellerhoff
authors: Christian
authors: C
authors: Pott
authors: Sven
authors: S
authors: Zumhagen
authors: Razvan
authors: R
authors: Radu
authors: Hans H
authors: HH
authors: Scheld
authors: Wilhelm
authors: W
authors: Haverkamp
authors: Eric
authors: E
authors: Schulze-Bahr
authors: Lars
authors: L
authors: Eckardt
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000628:therapy; D006801:Humans; D008133:Long QT Syndrome / Q000188:drug therapy / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents