title: Resting heart rate and risk of sudden cardiac death in the general population: influence of left ventricular systolic dysfunction and heart rate-modulating drugs.
abstract: BACKGROUND
  Higher levels of resting heart rate (HR) have been associated with sudden cardiac death (SCD) but mechanisms are poorly understood. We hypothesized that severe left ventricular systolic dysfunction (LVSD) and HR-modulating drugs explain the HR-SCD relationship.
  
  
  OBJECTIVE
  To evaluate the relationship between HR, severe LVSD, HR-modulating drugs, and SCD in the community by using a case-control approach.
  
  
  METHODS
  From the ongoing Oregon Sudden Unexpected Death Study, SCD cases (n = 378) aged ≥35 years and with electrocardiogram-documented resting HR were compared to 378 age- and gender-matched control subjects with coronary artery disease (mean age 68 ± 13 years; 69% man). Associations with SCD were assessed by using multivariable logistic regression.
  
  
  RESULTS
  Mean resting HR was significantly higher among SCD cases compared to controls (7.5 beats/min difference; P < .0001). HR was a significant determinant of SCD after adjustment for significant comorbidities and medications (odds ratio for 10 beats/min increase 1.26; 95% confidence interval 1.14-1.38; P < .0001). After considering LVSD, resting HR was slightly attenuated but remained significantly associated with SCD (P = .005). In addition to diabetes and digoxin as well as pulmonary and renal disease, LVSD was also independently associated with SCD (odds ratio 1.79; 95% confidence interval 1.11-2.87; P = .02).
  
  
  CONCLUSIONS
  Contrary to expectations, the significant relationship between increased resting HR and SCD persisted even after adjustment for LVSD and HR-modulating drugs. These findings suggest a potential role for additional novel interventions/therapies that modulate autonomic tone.
authors.affiliation: Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: Teodorescu
authors.forename: Kyndaron
authors.initials: K
authors.lastname: Reinier
authors.forename: Audrey
authors.initials: A
authors.lastname: Uy-Evanado
authors.forename: Karen
authors.initials: K
authors.lastname: Gunson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jui
authors.forename: Sumeet S
authors.initials: SS
authors.lastname: Chugh
mesh_terms: D000368:Aged; D002316:Cardiotonic Agents / Q000008:administration & dosage; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000150:complications* / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D003920:Diabetes Mellitus / Q000503:physiopathology; D004077:Digoxin / Q000008:administration & dosage; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
chemical_list: D002316:Cardiotonic Agents; D004077:Digoxin
keywords: Beta-blockers; CAD; CI; Cardiac arrest; Case-control study; EKG; EMS; HR; Heart failure; LVSD; Medications; Mortality; OR; SCD; confidence interval; coronary artery disease; electrocardiogram; emergency medical services; heart rate; left ventricular systolic dysfunction; odds ratio; sudden cardiac death