title: Tachycardia burden in stroke unit is associated with functional outcome after ischemic stroke.
abstract: BACKGROUND
  Stroke unit care is associated with decrease in mortality and improvement in neurological outcome in patients with acute stroke. Heart rate is a commonly monitored variable in the stroke unit. However, little is known about tachycardia burden in the stroke unit and its association with outcome.
  
  
  OBJECTIVE
  To investigate the effects of tachycardia burden in the stroke unit on functional outcome in patients with acute ischemic stroke.
  
  
  METHODS
  We collected data from 246 patients with acute ischemic stroke admitted to our stroke unit between July 2013 and June 2014. Tachycardia burden was defined as duration of heart rate over 95 per minute divided by the total monitoring time, using the heart rate data sampled every 1 min. We divided the study population into quartiles of tachycardia burden and analyzed their association with poor three-month functional outcome (modified Rankin Scale score of ≥3).
  
  
  RESULTS
  Among included patients (age, 67.4 ± 12.8; male, 53.7%), tachycardia burden was 0.7% (median, interquartile range [0.1-5.7%]). The patients with higher tachycardia burdens were older, more likely to have higher stroke severity, cardioembolic etiology, atrial fibrillation, fever, pneumonia, higher initial glucose level, and higher white blood cell count. As compared with the lowest quartile (<0.1%), the highest quartile of tachycardia burden (≥6.0%) was significantly associated with poor outcome (adjusted odds ratio, 5.10; 95% confidence interval, 1.38-18.90; p = 0.01) after adjustment for covariates.
  
  
  CONCLUSIONS
  Patients with increased tachycardia burden during stroke unit stay have poor functional outcome. Countermeasures against worsening factors might be utilized for patients with increased tachycardia burden.
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Han-Gil
authors: HG
authors: Jeong
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Sang-Bae
authors: SB
authors: Ko
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Chi Kyung
authors: CK
authors: Kim
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Yerim
authors: Y
authors: Kim
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Seunguk
authors: S
authors: Jung
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article.
authors: Tae Jung
authors: TJ
authors: Kim
authors: Department of Neurology, Seoul National University Hospital, Seoul, Republic of KoreaThe first two authors contributed equally to this article. bwyoon@snu.ac.kr.
authors: Byung-Woo
authors: BW
authors: Yoon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D013610:Tachycardia / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D015912:Thrombolytic Therapy; D016896:Treatment Outcome
keywords: Tachycardia; acute; heart rate; ischemic stroke; outcome; stroke units