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.