PP157 A MISDIAGNOSIS PROLONGED QT SYNDROME AS EPILEPSY - A CASE REPORT

Abstract

Introduction:

Long QT syndrome (LQTS) is a genetic ion channel disorder associated with recurrent syncope or seizures secondary to cerebral hypoxia during the arrhythmia. It affects 1 in 2000 people(1). LQTS accompanied by seizure can masquerade convincingly as epilepsy, leading to delay in both diagnosis and treatment, therefore exposing the patient to a high risk of sudden cardiac death.

Case Report:

33 year old woman presented to the emergency department with multiple seizure episodes. She is treated for epilepsy for more than 10 years and was discharged from a tertiary hospital earlier that day for Breakthrough seizure secondary to non-compliance to antiepileptics. Her reasoning were due to the poor response of her symptoms towards the medications. She had no neurological deficit and blood investigations were unremarkable. During observation, she developed a seizure characterised by rigid flexor posturing. Her rhythm during the episode showed the classic features of Torsades de Pointes. The seizure aborted alongside the spontaneous revert to sinus rhythm. A 12-lead ECG done then showed a corrected QT interval of 482ms. A cardiology referral was made which proceeded with an implantable cardioverter-defibrillator (ICD).

Discussion & Conclusion:

Misdiagnosis of LQTS presenting with seizures are common and often attributed to epilepsy. ECGs were frequently requested in patients with seizures, but interpretation errors were common. The changes might be subtle and the the prolongation can be easily overlooked. A high index of suspicion in the emergency department for alternate diagnosis in patients presenting with seizures not responding to antiepileptics despite on therapeutic levels is important. For these patients, continuous cardiac monitoring, careful ECG interpretation and examination of the arterial pulse is recommended. Appropriate intervention can significantly reduce mortality and morbidity, making prompt diagnosis essential.