Leuven, Belgium - Physicians in Belgium are warning colleagues about a misdiagnosis they say may be relatively common, particularly among young patients, but easily prevented with electrophysiological studies. Writing in the October 2007 issue of Heart Rhythm, Dr Tom Rossenbacker (University of Leuven, Belgium) and colleagues describe the case of a 15-year-old girl, misdiagnosed with epilepsy at age 11 and treated fruitlessly with antiepileptic drugs for four years before her true condition—long-QT syndrome—was discovered [1].

"Although we now describe a single case report, we have the feeling that many young patients who are referred to our Center for Hereditary Heart Diseases have been treated inappropriately in the past for 'epilepsy,' " Rossenbacker told heartwire. "Seemingly, many physicians have the reflex to assign fainting or syncope to a neurological disorder. First, they focus on the brain and the nervous system while assessing a young patient with syncope, and sometimes a trial therapy with antiepileptics is started. . . . With this case report, we hope to help educate all physicians involved in the care of patients with fainting [that] although not always that straightforward, the long-QT syndrome or other cardiac arrhythmias can sometimes be easily diagnosed with a few simple investigations."

In the case Rossenbacker et al describe, physicians diagnosed the 11-year-old as having epilepsy on the basis of her symptoms—weekly seizures—and clinical presentation. Long-QT syndrome was diagnosed only when the antiepileptic drugs failed to curb the seizures, and the patient underwent 24-hour electrocardiographic, electroencephalographic, and video recording; she fortuitously developed a convulsive seizure during the 24-hour period. A polymorphic ventricular tachycardia recorded at the onset of symptoms prompted further cardiac examination, ultimately leading to the diagnosis of long-QT syndrome.

According to the authors, the diagnosis of long-QT syndrome could have been made much earlier had an ECG been used in the initial diagnostic workup of the patient presenting with syncope.

In the case of the 15-year-old girl, her antiepileptic drugs were stopped and she was started on a course of beta blockers and potassium supplements, Rossenbacker told heartwire. She has also received an implantable defibrillator.

"She is doing very well and has not had another seizure attack for more than two years," he said.