title: Cardiac monitoring of high-dose verapamil in cluster headache: An international Delphi study.
abstract: BACKGROUND
  In many patients, high-dose verapamil (HDV) is the only effective prophylactic treatment for cluster headache. Although cardiac adverse events and EKG abnormalities are relatively common, evidence-based guidelines for screening and monitoring patients on HDV are lacking.
  
  
  OBJECTIVE
  Using the Delphi approach, we interviewed 22 international clinical experts in cardiac rhythm disorders to formulate EKG guidelines for the pretreatment screening and monitoring of cluster headache patients using HDV.
  
  
  RESULTS
  The panel agreed only on performing pretreatment EKG to screen for pre-existing cardiac arrhythmia. Pretreatment EKG was deemed not necessary by most panel members for patients who did not have cardiac adverse events during a previous period of cluster headache attacks treated with HDV. Half the panel advised Holter EKG for patients on verapamil ≥ 480 mg/day. The highest recommended daily doses varied between 240 and 960 mg. Contraindications for use of verapamil largely followed FDA guidelines.
  
  
  CONCLUSIONS
  Experts in cardiac rhythm disorders agreed on pretreatment EKG monitoring, but no consensus was reached on EKG monitoring during HDV treatment and around dose adjustments.
authors: Department of Neurology, Haga Hospital, The Netherlands h.koppen@hagaziekenhuis.nl.
authors: H
authors: H
authors: Koppen
authors: Department of Neurology, Haga Hospital, The Netherlands.
authors: J
authors: J
authors: Stolwijk
authors: Department of Clinical Pharmacy, Haga Hospital, The Netherlands.
authors: E B
authors: EB
authors: Wilms
authors: Department of Cardiology Haga Hospital, The Netherlands.
authors: V
authors: V
authors: van Driel
authors: Department of Neurology, Leiden University Medical Center, The Netherlands.
authors: M D
authors: MD
authors: Ferrari
authors: Department of Neurology, Rijnland Hospital Leiderdorp and Leiden University Medical Center, The Netherlands.
authors: J
authors: J
authors: Haan
mesh_terms: D000072096:Cardiologists; D003027:Cluster Headache / Q000175:diagnosis / Q000188:drug therapy*; D003697:Delphi Technique; D004562:Electrocardiography / Q000379:methods*; D006801:Humans; D038622:Internationality; D011897:Random Allocation; D014665:Vasodilator Agents / Q000627:therapeutic use*; D014700:Verapamil / Q000627:therapeutic use*
chemical_list: D014665:Vasodilator Agents; D014700:Verapamil
keywords: Cluster headache; EKG; heart; verapamil