title: The feasibility of recognizing the heart rhythm with an automated external defibrillator from an area the size of a mobile phone.
abstract: OBJECTIVE
  Recognition of cardiac arrest (CA) during an emergency call leans on questions concerning CA symptoms and is correct in 50-83% of cases. If the heart rhythm could be recorded and analysed over a mobile phone or transmitted during the emergency call to the dispatch centre and analysed there, using software identical to one in an automated external defibrillator (AED), CA recognition could be more prompt. We investigated whether an AED can correctly analyse normal heart rhythms recorded within an area the size of a mobile phone.
  
  
  METHODS
  Bipolar ECG signal was recorded using an AED in 20 healthy volunteers in four different positions during rest and muscle tension with small pads in an area the size of a mobile phone. Recordings obtained with standard pads in standard positions served as the reference. The recorded ECGs were analysed with an AED and by two cardiologists and categorized as shockable or nonshockable.
  
  
  RESULTS
  All analyses were correct when the recordings were performed vertically at the midsternum level. Horizontally at this level, the AED made correct analyses in 95 and 65% of cases and the cardiologists in 100 and 88% of cases at rest and during muscle tension, respectively. In the lateral positions only the analyses by cardiologists partly reached 100% sensitivity. The analysis time of the AED was 7 s in all positions.
  
  
  CONCLUSIONS
  ECGs can be analysed promptly with an AED within an area the size of a mobile phone. The most reliable recording position was vertical at the midsternum level.
authors.affiliation: aDepartments of Anaesthesia and Intensive Care bInternal Medicine, North Karelia Central Hospital, Joensuu cHeart Center dDepartment of Intensive Care eCentre for Prehospital Emergency Care, Kuopio University Hospital, Kuopio, Finland fDepartment of Clinical Science and Education, Section of Emergency Medicine, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden.
authors.forename: Sakari
authors.initials: S
authors.lastname: Syväoja
authors.forename: Maaret
authors.initials: M
authors.lastname: Castren
authors.forename: Pirjo
authors.initials: P
authors.lastname: Mäntylä
authors.forename: Tuomas T
authors.initials: TT
authors.lastname: Rissanen
authors.forename: Antti
authors.initials: A
authors.lastname: Kivelä
authors.forename: Ari
authors.initials: A
authors.lastname: Uusaro
authors.forename: Helena
authors.initials: H
authors.lastname: Jäntti
mesh_terms: D000328:Adult; D047548:Defibrillators; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000502:physiology; D006801:Humans; D008297:Male; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis / Q000503:physiopathology