Junctional bradycardia is a potential risk factor of stroke

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.