title: Prognostic value of heart rate turbulence for risk assessment in patients with unstable angina and non-ST elevation myocardial infarction.
abstract: BACKGROUND
  We sought to examine the prognostic value of heart rate turbulence derived from electrocardiographic recordings initiated in the emergency department for patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina.
  
  
  METHODS
  Twenty-four-hour Holter recordings were started in patients with cardiac symptoms approximately 45 minutes after arrival in the emergency department. Patients subsequently diagnosed with NSTEMI or unstable angina who had recordings with ≥18 hours of sinus rhythm and sufficient data to compute Thrombolysis In Myocardial Infarction (TIMI) risk scores were chosen for analysis (n = 166). Endpoints were emergent re-entry to the cardiac emergency department and/or death at 30 days and one year.
  
  
  RESULTS
  In Cox regression models, heart rate turbulence and TIMI risk scores together were significant predictors of 30-day (model chi square 13.200, P = 0.001, C-statistic 0.725) and one-year (model chi square 31.160, P < 0.001, C-statistic 0.695) endpoints, outperforming either measure alone.
  
  
  CONCLUSIONS
  Measurement of heart rate turbulence, initiated upon arrival at the emergency department, may provide additional incremental value in the risk assessment for patients with NSTEMI or unstable angina.
authors: School of Nursing, Department of Physiological Nursing, University of California, San Francisco, CA 94143-0610, USA. patriciarae.harris@ucsf.edu
authors: Patricia R E
authors: PR
authors: Harris
authors: Phyllis K
authors: PK
authors: Stein
authors: Gordon L
authors: GL
authors: Fung
authors: Barbara J
authors: BJ
authors: Drew
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D016507:Cardiology Service, Hospital; D016009:Chi-Square Distribution; D015716:Electrocardiography, Ambulatory; D004636:Emergency Service, Hospital; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: acute coronary syndrome; electrocardiographic monitoring; heart rate turbulence; non-ST elevation myocardial infarction; outcomes; prognosis; unstable angina
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