title: Antecedent bradycardia and in-hospital cardiopulmonary arrest mortality in telemetry-monitored patients outside the ICU.
abstract: BACKGROUND
  Patients with in-hospital cardiopulmonary arrest (IHCA) precipitated by respiratory insufficiency often exhibit bradycardia before the arrest. We hypothesized that bradycardia frequently occurs in the 10 min preceding IHCA and is associated with poor outcomes when IHCA occurs outside the intensive care unit (ICU).
  
  
  OBJECTIVE
  To determine the prevalence and association of antecedent bradycardia with outcome in adult patients with IHCA occurring outside the ICU.
  
  
  METHODS
  We performed a retrospective cohort study among telemetry monitored adults with IHCA outside the ICU in a two-hospital health system between 2008 and 2010 with follow-up until their discharge or death in-hospital. We defined (1) IHCA as >1 min of chest compressions or trans-thoracic defibrillation, (2) Antecedent bradycardia as at least 2 min of continuous heart rate between 1 and 59 beats per minute in the 10min preceding IHCA, and (3) ventricular tachyarrhythmia arrests as presence of sustained ventricular tachyarrhythmia for >20 s in the 10 min preceding IHCA.
  
  
  RESULTS
  Of 98 IHCAs, 39 (39.8%) survived to hospital discharge. Of 98 IHCAs, 53 (54.1%) had antecedent bradycardia. After adjusting for potential confounders, antecedent bradycardia was associated with death prior to hospital discharge (adjusted OR=3.80, 95% CI: 1.47-9.81, p=0.006). Among patients with ventricular tachyarrhythmia arrests, antecedent bradycardia was associated with a higher risk of death (OR=13.1, 95% CI 1.92-89.5, p=0.009).
  
  
  CONCLUSIONS
  Antecedent bradycardia occurred frequently and was associated with death prior to hospital discharge in non-ICU hospitalized adults on telemetry monitoring who developed IHCA.
authors.affiliation: The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Utpal S
authors.initials: US
authors.lastname: Bhalala
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Bonafide
authors.forename: Christian M
authors.initials: CM
authors.lastname: Coletti
authors.forename: Penny E
authors.initials: PE
authors.lastname: Rathmanner
authors.forename: Vinay M
authors.initials: VM
authors.lastname: Nadkarni
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Anita K
authors.initials: AK
authors.lastname: Witzke
authors.forename: Melody S
authors.initials: MS
authors.lastname: Kasprzak
authors.forename: Marc T
authors.initials: MT
authors.lastname: Zubrow
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001919:Bradycardia / Q000150:complications* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality*; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D015996:Survival Rate; D013686:Telemetry