Unveiling the Hidden Culprit: A Case Report on Tachy-Bradyarrhythmias Presenting as Seizure Disorders

The misdiagnosis of seizure disorders in patients with cardiogenic syncope and tachy-bradyarrhythmias is a significant diagnostic challenge as the differentials for altered mental status and syncope are broad and can mimic other clinical conditions. This case report presents a unique case of an elderly male with life-threatening ventricular arrhythmia, initially misdiagnosed as a seizure disorder associated with syncope and treated with anti-epileptics for a neurogenic cause, before an ambulatory cardiac monitor revealed a sinister cardiogenic etiology.

An 87-year-old man with ischemic cardiomyopathy (LVEF 20%) and persistent atrial fibrillation presented for implantable cardioverter-defibrillator (ICD) evaluation following a ventricular fibrillation (VF) arrest. He had a history of recurrent syncope accompanied by muscle jerking and was initially treated with anti-epileptic drugs. However, further evaluation with mobile telemetry revealed ventricular arrhythmias, including nonsustained VT, VF, and asystole. Anti-epileptic medications were discontinued, and the patient was started on amiodarone. A cardiac resynchronization therapy defibrillator (CRT-D) was implanted, which successfully resolved his symptoms. Post-treatment, he remained asymptomatic, with no new VT/VF episodes detected at one week and three months during follow-up device checks.

This case underscores the importance of considering cardiogenic causes in patients with syncope and seizure-like symptoms. Therefore, a multidisciplinary approach is essential for accurate diagnosis and management.