Long QT syndrome manifesting as pulseless epilepsy

Clinical profile of pediatric patients with long QT syndrome masquerading as seizures

OBJECTIVE

To study the clinical profile of patients with long QT syndrome presenting as seizures.

METHODS

Retrospective analysis of six pediatric patients admitted at authors' institute between October 2008 and January 2013 with seizures and a presumptive diagnosis of long QT syndrome (LQTS) was done. The diagnosis was made on the basis of updated Schwartz diagnostic criteria. Clinical data, investigation profile and follow up of patients was recorded in a standard format and analysed.

RESULTS

All the 6 patients in the study were boys with a mean age of 10.3 ± 2.8 y at the time of diagnosis. The lag period between symptom onset and diagnosis was 5.6 ± 3.14 y. All patients had history of seizures with a history of precipitating event in 4 patients. Average baseline QTc interval was 556 ± 41.31 ms. Mean Schwartz score was 6.66 ± 1.16. Polymorphic VT was documented in 4 patients. After initiating standard treatment with betablockers, nicorandil, spironolactone or pacemaker, all the six patients were asymptomatic at a mean follow up period of 17.5 mo, with no recurrence of seizures.

CONCLUSIONS

LQTS can cause seizures due to prolonged ventricular arrhythmias in high risk subgroup. Children, who present with LQTS and seizures, generally have a precipitating event causing seizures, and they respond well to drug therapy.

Jervell and Lange-Nielson Syndrome masquerading as intractable epilepsy

The long QT syndrome (LQTS) is a cause of syncope and sudden death. Jervell and Lange–Nielson syndrome (JLNS) is an uncommon form of LQTS, having autosomal recessive transmission, and is associated with congenital deafness. We report a case of JLNS in a child who presented to us with refractory epilepsy. The cardiac cause of seizures was suspected as the child was hypotensive and pulseless during the episode of seizures. The child was diagnosed as JLNS based on Schwartz diagnostic criteria for LQTS and congenital sensorineural deafness. The child responded well to β-blocker therapy. Antiepileptic drugs were stopped. The screening of family members with ECG revealed a QT interval more than required for diagnosis of LQTS but they were asymptomatic. All asymptomatic family members were also put on metoprolol. All of them showed great improvement with the reduction of the QT interval on ECG. The patient was doing well on immediate follow-up.