title: The role of catheter ablation in the management of patients with implantable cardioverter defibrillators presenting with electrical storm.
abstract: OBJECTIVE
  Electrical storm (ES) is not uncommon among patients with an implantable cardioverter defibrillator (ICD) in situ. Catheter ablation (CA) may suppress the arrhythmia in the acute setting and prevent ES recurrence.
  
  
  METHODS
  Nineteen consecutive patients with an ICD in situ presenting with ES underwent electrophysiologic studies followed by CA. CA outcome was classified as a complete success if both clinical and non-clinical tachycardia were successfully ablated, partial success if ≥1 non-clinical tachycardia episodes were still inducible post-CA, and failure if clinical tachycardia could not be abolished. Patients were followed for a median period (IQR) of 5.6 (1.8-13.7) months. The primary endpoint was event-free survival from ES recurrence. The secondary endpoint was event-free survival from a composite of ES and/or sustained ventricular tachycardia (VT) recurrence.
  
  
  RESULTS
  Clinical arrhythmia was successfully ablated in 14 out of 19 (73.7%) cases after a single CA procedure. A completely successful CA outcome was associated with significantly increased ES-free survival compared with a partially successful or failed procedure (Log rank P=0.039). Nevertheless, patients with acute suppression of all tachycardia episodes (n=11), relative to those with a partially successful or a failed CA procedure (n=8), did not differ in incidence of the composite endpoint of sustained VT or ES (Log rank P=0.278).
  
  
  CONCLUSIONS
  A single CA procedure can acutely suppress clinical arrhythmia in three-quarters of cases. A completely successful CA outcome can prolong ES-free survival; however, sporadic ICD therapies cannot be abrogated.
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Stelios
authors.initials: S
authors.lastname: Paraskevaidis
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece. Electronic address: dkon@hotmail.gr.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Konstantinou
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Vassilios
authors.initials: V
authors.lastname: Kolettas
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Stavropoulos
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Koutsakis
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Chrysovalantou
authors.initials: C
authors.lastname: Nikolaidou
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Ziakas
authors.affiliation: First Cardiology Department, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Haralambos
authors.initials: H
authors.lastname: Karvounis
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D018572:Disease-Free Survival; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome
keywords: Catheter ablation; Electrical storm; Implantable cardioverter defibrillator