Not Every Symptomatic Bradycardia Needs a Pacemaker: A Rare Case of Reversible Bradycardia Due to Bowel Obstruction [Conference Winner Abstract]

Introduction Symptomatic bradycardia due to sinus node dysfunction (SND) is one of the most common indications for permanent pacemaker implantation [1]. Mostly associated with intrinsic cardiac causes such as idiopathic fibrosis, age-related degeneration or ischemic heart disease, it can, however, occasionally arise due to extrinsic factors, including gastrointestinal (GI) disorders [2]. This case illustrates an uncommon occurrence of transient junctional rhythm with severe bradycardia brought on by bowel obstruction. Case Presentation A 59-year-old man presented to the emergency department (ED) with syncope, abdominal pain and nausea. Syncopal episodes continued in the ED, where junctional rhythm with severe bradycardia was recorded, prompting admission to the cardiac ICU for further evaluation. His past medical history included poliarthritis. The patient noted a week-long history of abdominal pain, nausea and vomiting which lead to further evaluation for possible extrinsic bradycardia causes. Abdominal ultrasound revealed dilated small intestines and abnormal peristalsis. A CT scan confirmed small bowel obstruction likely due to internal hernia. Due to persistent bradycardia, a temporary pacing lead was inserted and a laparotomy was performed to treat the ileus. Postoperatively, bradycardia resolved completely and a permanent pacemaker was no longer indicated. The patient was discharged after successful postoperative care. Discussion Sinus node dysfunction caused by extrinsic factors is rarer compared to intrinsic cardiac causes, with few cases demonstrating reversible bradycardia linked to GI pathologies [3]. In this patient, bowel obstruction was the likely trigger for junctional rhythm with severe bradycardia, as evidenced by the absence of conduction abnormalities post-surgery. Potential mechanisms include prolonged abdominal distention and vagus nerve irritation, leading to increased vagal tone and disrupted conduction [3]. Prognosis is more favorable in patients with reversible causes, unlike intrinsic cardiac disease, which often requires permanent pacemaker implantation. Conclusions This case demonstrates a rare yet clinically significant association between symptomatic bradycardia and GI disease, emphasizing detailed evaluation of reversible factors and timely intervention to optimize outcomes.