title: The significance of heart rate turbulence in predicting major cardiovascular events in patients after myocardial infarction treated invasively.
abstract: BACKGROUND
  The role of heart rate turbulence (HRT) related to baroreflex sensitivity in predicting mortality after myocardial infarction (MI) has been confirmed by several investigators. However, the significance of HRT in predicting major adverse cardiovascular events (MACE) following acute MI is unknown.
  
  
  OBJECTIVE
  To analyze the prognostic value of HRT and other independent risk factors associated with autonomic regulation of MACE.
  
  
  METHODS
  HRT was assessed based on 24-hour Holter recordings in 500 patients (pts) with acute MI treated invasively (352 M, aged 60.58 years). Turbulence onset (TO,%), slope (TS, ms/RR interval) and timing (TT) were calculated. TO ≥ 0, TS ≤ 2.5 and TT ≥ 10 were considered abnormal; classic and own categories were defined. Time domain heart rate variability (HRV) parameters were also calculated. Within 30.1 ± 15.1 months of follow-up, MACE occurred in 116 pts.
  
  
  RESULTS
  Abnormal TO, TS, and TT were significantly more frequent in patients with MACE (P < 0.05 for each parameter, classic and own categories). In long-term follow-up, the largest differences in MACE were observed in patients with own category comprising abnormal TO, TS, and TT. Combining HRT parameters with SDNN (total HRV index) augmented their predictive value. Independent risk factors for MACE were TT, SDNN and rMSSD (a parasympathetic activity index) (HR 2.44, 1.71 and 1.69 respectively; P < 0.05).
  
  
  CONCLUSIONS
  Abnormal HRT distinguishes patients at risk of MACE after MI. Own category encompassing three abnormal HRT parameters best differentiates patients at risk of MACE. Turbulence timing is a strong independent risk factor for MACE following MI.
authors: Department of Cardiology, Congenital Heart Diseases and Electrotherapy, Medical University of Silesia, Silesian Center for Heart Diseases, Zabrze, Poland.
authors: Sylwia
authors: S
authors: Cebula
authors: Beata
authors: B
authors: Sredniawa
authors: Jacek
authors: J
authors: Kowalczyk
authors: Agata
authors: A
authors: Musialik-Lydka
authors: Aleksandra
authors: A
authors: Wozniak
authors: Agnieszka
authors: A
authors: Sedkowska
authors: Andrzej
authors: A
authors: Swiatkowski
authors: Zbigniew
authors: Z
authors: Kalarus
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary / Q000379:methods / Q000401:mortality; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology