Case Report: Post-ictal Atrial Fibrillation Following Generalized Tonic–Clonic Seizure in a Patient with Known Epilepsy.

Post-ictal Atrial Fibrillation Following Generalized Tonic–Clonic Seizure in a Patient with Known Epilepsy. Abstract: Atrial fibrillation (AF) is a rare but clinically significant peri-ictal cardiac arrhythmia that may complicate epileptic seizures and increase the risk of thromboembolic events. New-onset arrhythmias have been described generally as tachyarrhythmias. A 47-year-old man with established epilepsy developed new-onset post-ictal atrial fibrillation in our ED. Baseline cardiac investigations and laboratory studies were unremarkable. This case highlights the importance of systematic post-ictal cardiac monitoring, evaluation for triggers, and consideration of anticoagulation with cardiology follow-up in selected patients. Introduction: Benign sinus tachycardia has been documented in peri-ictal period. However, peri-ictal atrial fibrillation (AF) is rarely reported and is primarily described as “post-ictal” or “seizure-associated” AF. The underlying mechanisms remain incompletely understood. Existing literature suggests that seizure-associated AF often occurs in structurally normal hearts, and may be transient. We describe a case of post-ictal AF in a middle-aged man with known epilepsy and normal baseline systemic and cardiac evaluations. Case Report: A 47-year-old man with a previous medical history of generalized epilepsy, on levetiracetam 750 mg twice daily presented to the emergency department (ED) after experiencing a generalized tonic–clonic seizure. His most recent seizure had occurred one month prior. He denied fever, systemic symptoms, substance use, or recent medication changes. On arrival, he was fully oriented and hemodynamically stable except for tachycardia (132 beats/min). Vital signs were normal. Systemic examination was normal, with a superficial 1-cm occipital laceration presumed secondary to seizure-related trauma. Initial ECG showed sinus tachycardia without ischemic changes. Laboratory tests and chest radiography were normal. A head CT scan was planned. While awaiting imaging, the patient experienced a generalized tonic–clonic seizure lasting approximately 45 seconds. He was treated according to institutional protocol. In the post-ictal period an irregularly irregular rhythm with frequent escape beats was noted prompting a repeat 12-lead ECG, which displayed atrial fibrillation with a ventricular rate of 110 beats/min. No prior history of AF, hypertension, hyperthyroidism, or structural heart disease was identified. Cardiac troponins and transthoracic echocardiography were normal, with no structural abnormalities or intracardiac thrombus. Non-contrast brain CT showed no acute pathology. Cardiology and neurology consultations were obtained. The patient’s scalp laceration was treated, and he was discharged with instructions for close outpatient follow-up. At one-month cardiology review, the patient remained asymptomatic, and ECG demonstrated normal sinus rhythm. Anticoagulation was deferred based on a low CHA₂DS₂-VASc score and multidisciplinary consensus. Plans were made for ongoing cardiology and neurology follow-up, optimization of antiseizure therapy, and monitoring for recurrent arrhythmia. Conclusion: This case highlights a rare instance of post-ictal atrial fibrillation occurring after a generalized tonic–clonic seizure in a patient with established epilepsy with a structurally normal heart and compliant with antiepileptic medication. The arrhythmia resolved spontaneously, suggesting autonomic or neurogenic mechanisms rather than primary cardiac pathology. Though the proposed pathophysiology is not certain, seizure-associated AF raises concern for both immediate hemodynamic consequences and longer-term thromboembolic risk. Paroxysmal AF is independently associated with stroke, and seizure-triggered AF may go undetected without continuous monitoring. Several authors recommend routine post-ictal ECGs after generalized seizures to avoid missed diagnoses. Decisions regarding anticoagulation require individualized risk assessment, including careful observation, seizure control, and cardiology follow‑up, while recurrent or prolonged AF may justify anticoagulation. Post-ictal AF in persons with epilepsy , on medication and with no cardiac structural anomaly suggests the need for further studies.