title: Junctional bradycardia is a potential risk factor of stroke.
abstract: BACKGROUND
  This study aimed to determine the risk of thromboembolic events in patients with junctional bradycardia(JB).
  
  
  METHODS
  We retrospectively reviewed electrocardiograms(ECGs) for 380,682 patients. Those with JB on an ECG at least twice over a ≥3-month interval were included for analysis. We additionally included 138 CHADS2 score-matched patients(age, 68.4 ± 15.7 years; male, 52.2%) in sinus rhythm as a control group. Between the JB patients(with or without retrograde P wave) and controls, we compared incidences of ischemic stroke and a composite of ischemic stroke, renal infarction, ischemic colitis, acute limb ischemia, and pulmonary embolism.
  
  
  RESULTS
  Among 380,682 patients (age, 47.6 ± 19.9 years; male, 49.3%), 69 patients (age, 68.5 ± 16.5 years; male, 50.7%) exhibited JB on an ECG at least twice over a ≥3-month interval; the overall prevalence of JB was 0.02%. The mean follow-up period was 27.2 ± 26.2 months. Forty-five patients (65.2%) in the JB group had no retrograde P wave. Ischemic stroke incidence was significantly higher in JB patients without a retrograde P wave than in controls (6/45 patients [13.3%] and 3/138 patients [2.2%], respectively; P = 0.007). The incidence of composite thromboembolic events was also significantly higher in JB patients without a retrograde P wave than in controls (8/45 patients [17.8%] and 4/138 patients [2.9%], respectively; P = 0.011). In a Cox proportional hazards model, JB patients without a P wave showed a greater incidence of stroke (hazard ratio, 8.89 [2.20-33.01], P = 0.007) than controls and JB patients with a P wave.
  
  
  CONCLUSIONS
  Junctional bradycardia is potentially associated with ischemic stroke, particularly in the absence of an identifiable retrograde P wave.
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Gwang Sil
authors.initials: GS
authors.lastname: Kim
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Jae-Sun
authors.initials: JS
authors.lastname: Uhm
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Hancheol
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Junbeom
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Park
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Boyoung
authors.initials: B
authors.lastname: Joung
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.affiliation: Department of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro Seodaemun-gu, Seoul, Republic of Korea. mhlee@yuhs.ac.
authors.forename: Moon-Hyoung
authors.initials: MH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis; D001919:Bradycardia / Q000175:diagnosis*; D002545:Brain Ischemia / Q000175:diagnosis; D016022:Case-Control Studies; D017091:Colitis, Ischemic / Q000175:diagnosis; D004562:Electrocardiography / Q000379:methods; D005121:Extremities / Q000098:blood supply; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007238:Infarction / Q000175:diagnosis; D007511:Ischemia / Q000175:diagnosis; D007668:Kidney / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis*; D013923:Thromboembolism / Q000175:diagnosis
keywords: Junctional bradycardia; Stroke; Thromboembolic events