title: Expiration-Triggered Sinus Arrhythmia Predicts Outcome in Survivors of Acute Myocardial Infarction.
abstract: Respiratory sinus arrhythmia (RSA), a measure of cardiac vagal modulation, provides cardiac risk stratification information. RSA can be quantified from Holter recordings as the high-frequency component of heart rate variability or as the variability of RR intervals in individual respiratory cycles. However, as a risk predictor, RSA is neither exceptionally sensitive nor specific.
  
  
  
  This study aimed to improve RSA determination by quantifying the amount of sinus arrhythmia related to expiration (expiration-triggered sinus arrhythmia [ETA]) from short-term recordings of electrocardiogram and respiratory chest excursions, and investigated the predictive power of ETA in survivors of acute myocardial infarction.
  
  
  
  Survivors of acute myocardial infarction (N = 941) underwent 30-min recordings of electrocardiogram and respiratory chest excursions. ETA was quantified as the RR interval change associated with expiration by phase-rectified signal averaging. Primary outcome was 5-year all-cause mortality. Univariable and multivariable Cox regression was used to investigate the association of ETA with mortality.
  
  
  
  ETA was a strong predictor of mortality, both in univariable and multivariable analysis. In a multivariable model including respiratory rate, left ventricular ejection fraction, diabetes mellitus, and GRACE score, ETA ≤0.19 ms was associated with a hazard ratio of 3.41 (95% confidence interval: 1.10 to 5.89, p < 0.0001). In patient subgroups defined by abnormal left ventricular ejection fraction, increased respiratory rate, high GRACE score, or presence of diabetes mellitus, patients were classified as high or low risk on the basis of ETA.
  
  
  
  Expiration-triggered sinus arrhythmia (ETA) is a potent and independent post-infarction risk marker.
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sinnecker
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Dommasch
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Steger
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Berkefeld
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Hoppmann
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Müller
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Gebhardt
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Barthel
authors.affiliation: Saint Paul's Cardiac Electrophysiology, University of London and Imperial College, London, London, United Kingdom.
authors.forename: Katerina
authors.initials: K
authors.lastname: Hnatkova
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Huster
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany.
authors.forename: Karl-Ludwig
authors.initials: KL
authors.lastname: Laugwitz
authors.affiliation: Saint Paul's Cardiac Electrophysiology, University of London and Imperial College, London, London, United Kingdom.
authors.forename: Marek
authors.initials: M
authors.lastname: Malik
authors.affiliation: 1. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany. Electronic address: gschmidt@tum.de.
authors.forename: Georg
authors.initials: G
authors.lastname: Schmidt
mesh_terms: D000368:Aged; D001146:Arrhythmia, Sinus / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000453:epidemiology; D004562:Electrocardiography; D045853:Exhalation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology*; D012119:Respiration; D056152:Respiratory Rate / Q000502:physiology; D018570:Risk Assessment; D013318:Stroke Volume / Q000502:physiology
keywords: heart rate variability; phase-rectified signal averaging; respiratory sinus arrhythmia; risk stratification