title: A formula for the stratified selection of patients with paroxysmal atrial fibrillation in the emergency setting: a retrospective pilot study.
abstract: BACKGROUND
  Amiodarone is a commonly used medication in the treatment of atrial fibrillation (AF) of recent onset.
  
  
  OBJECTIVE
  The aim of the study was to identify a possible formula for selecting Emergency Department (ED) patients with paroxysmal AF who will spontaneously restore sinus rhythm (SR), successfully restore SR with the use of loading intravenous (i.v.) amiodarone, or require 24-h maintenance amiodarone infusion.
  
  
  METHODS
  This retrospective pilot study included 141 patients with recent-onset AF. Patients who did not restore SR spontaneously received i.v. amiodarone (5 mg/kg) within a period of 30 min. In case of no response, an additional dosage of 1000 mg of i.v. amiodarone was administered over a period of 24 h. Binary logistic regression models were used to determine the predictors of spontaneous conversion and the response to amiodarone administration.
  
  
  RESULTS
  The formula ([heart rate/systolic blood pressure] + 0.1 × number of past AF incidences) was chosen as the one with the highest combined sensitivity and specificity. This index identified the patients who spontaneously restored SR (cutoff point 1.31 with 78.6% sensitivity and 77.9% specificity), whereas for patients who responded to the loading i.v. amiodarone dose, the use of the index (cutoff point 1.24) exhibited 84.1% sensitivity and 75.3% specificity.
  
  
  CONCLUSIONS
  This formula may be a useful and reliable bedside diagnostic tool to identify AF patients most likely to spontaneously convert, or respond to loading amiodarone administration in the emergency setting. The use of this index also can assist in patient risk stratification.
authors.affiliation: Department of Experimental Surgery and Surgical Research, N.S.Christeas, Athens School of Medicine, Athens, Greece.
authors.forename: Despina N
authors.initials: DN
authors.lastname: Perrea
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Ekmektzoglou
authors.forename: Ioannis S
authors.initials: IS
authors.lastname: Vlachos
authors.forename: Serafim
authors.initials: S
authors.lastname: Tsitsilonis
authors.forename: Eleni
authors.initials: E
authors.lastname: Koudouna
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Stroumpoulis
authors.forename: Theodoros
authors.initials: T
authors.lastname: Xanthos
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000188:drug therapy* / Q000503:physiopathology; D001794:Blood Pressure; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital; D005260:Female; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone