title: Ventricular ectopic burden in comatose survivors of out-of-hospital cardiac arrest treated with targeted temperature management at 33°C and 36°C.
abstract: OBJECTIVE
  Life threatening arrhythmias are increasingly frequent with lower body temperature. While targeted temperature management (TTM) with mild hypothermia following out-of-hospital cardiac arrest (OHCA) is generally considered safe and has been suggested as a potential antiarrhythmic add-on therapy, it is unknown whether the level of TTM affects the burden of ventricular ectopic activity. We sought to assess the ventricular ectopic burden between patients treated with TTM at 33°C or 36°C for 24h.
  
  
  METHODS
  Continuous 12-lead digital Holter electrocardiograms performed during the intervention were analyzed blinded to treatment allocation in 115 comatose OHCA-survivors from a single center of the TTM-trial. The main study showed no difference with regards to mortality.
  
  
  RESULTS
  Fifty-eight patients were randomized to 33°C and 57 to 36°C. Cardiac arrest characteristics were similar between the groups. The number of isolated ventricular ectopic beats (VEB) per hour was similar at the beginning of the maintenance phase of TTM and decreased over time in both groups (both ptime<0.001). The reduction in VEB per hour was significantly affected by target temperature (pinteraction<0.0001), with fewer VEB in the 36°C-group. The total number of isolated, couplets and number of runs of VEB per hour showed similar results, with less ventricular ectopic activity in the 36°C-group (pinteraction<0.0001). Increasing numbers of pre-hospital defibrillations (log2) were associated with a 46% increase in ventricular ectopic activity (p<0.01), adjusted for potential confounders.
  
  
  CONCLUSIONS
  Ventricular ectopic activity was reduced in comatose OHCA-survivors treated with TTM at 36°C compared to 33°C. Higher numbers of pre-hospital defibrillations were associated with higher incidence of ventricular ectopic activity.
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark. Electronic address: jakob@jht.dk.
authors.forename: Jakob Hartvig
authors.initials: JH
authors.lastname: Thomsen
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
authors.affiliation: Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D2, 9220 Aalborg, Denmark.
authors.forename: Claus
authors.initials: C
authors.lastname: Graff
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Pehrson
authors.affiliation: Department of Cardiology, Lund University Hospital, SE-221 85 Lund, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Erlinge
authors.affiliation: Department of Thoracic Anaesthesiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Wanscher
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: John
authors.initials: J
authors.lastname: Bro-Jeppesen
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Søholm
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Matilde
authors.initials: M
authors.lastname: Winther-Jensen
authors.affiliation: Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen O, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Hassager
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003128:Coma / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications* / Q000628:therapy; D016896:Treatment Outcome; D018879:Ventricular Premature Complexes / Q000209:etiology* / Q000503:physiopathology
keywords: Comatose; Out-of-hospital cardiac arrest; Targeted temperature management; Therapeutic hypothermia; Ventricular arrhythmia; Ventricular ectopic activity