B51-27 Syncope or Seizure? Intermittent Complete AV Block in a Patient With Multiple Comorbidities

Introduction Distinguishing between syncope and seizure can be challenging, particularly in elderly patients with multiple comorbidities. Cardiac conduction abnormalities, such as intermittent atrioventricular (AV) block, may mimic seizure activity and lead to diagnostic confusion. In patients with chronic kidney disease (CKD) and coronary artery disease (CAD), recognizing cardiac causes of transient loss of consciousness is essential to prevent life-threatening outcomes. We present a case of intermittent complete AV block in a 73-year-old woman whose initial presentation resembled recurrent seizures, highlighting the importance of timely diagnosis and intervention. Case Description A 73-year-old woman with CKD stage 5, CAD, hypertension, gastroesophageal reflux disease, and diabetes mellitus presented after a possible syncopal versus seizure episode. Symptoms included generalized weakness, dizziness, and chills after receiving a Darbepoetin Alfa injection, followed by a fall with head and chest trauma. Family members reported four to five brief episodes characterized by arm stiffening, upward eye deviation, diaphoresis, and fecal incontinence.On arrival, she was hypertensive and weak but responsive. Examination revealed tenderness in the right chest and scalp and a pansystolic murmur. Laboratory tests showed elevated lactate (3.0 mmol/L), CPK (200 U/L), glucose (226 mg/dL), creatinine (4.0 mg/dL), and BUN (71 mg/dL). Troponin levels were negative, and the ECG demonstrated a right bundle branch block. Brain and neck CT were unremarkable, and echocardiography revealed preserved systolic function (LVEF 73%). Continuous cardiac monitoring identified intermittent complete AV block with ventricular asystole lasting up to 7 seconds. A dual-chamber pacemaker was successfully implanted, resulting in resolution of symptoms. She was discharged after a five-day hospital stay. Discussion This case illustrates the diagnostic challenge of distinguishing seizure-like activity from cardiac syncope in elderly patients with complex medical histories. The patient’s conduction abnormality was initially masked by overlapping symptoms, underscoring the need for vigilance and continuous cardiac monitoring. Timely pacemaker implantation led to marked clinical improvement and prevented potentially fatal arrhythmias. Conclusion In patients with multiple comorbidities, episodes resembling seizures may represent cardiac conduction disturbances. Comprehensive evaluation and prompt pacing intervention can be lifesaving and significantly improve outcomes.