[SCD-FORUM] 145S Long QT. Dr. Stefani

[SCD Symposium]

Dear colleagues, 
My name is Amalia Stefani. I am a pediatric cardiologist and I work with the team of Dr. Claudio de Zuloaga in the Posadas Hospital, from Buenos Aires, Argentina. 
The reason for this message is to request your evaluation and opinion about a patient with long QT, who has recently come to our service. 

7 years old. Male. Long QT (QTc 0.52), type 3 by electrocardiographic pattern (no genetic confirmation). Two syncopes in rest, the second one with tonic-clonic convulsion. With no medication that would prolong QT. 
Normal lab tests. History of competent bicuspid aortic valve. Monitoring while in hospital and Holter with no detection of arrhythmia. 
We started treatment with propanolol at 2 mg/kg/day orally, no changes in the QTc with a good dose of beta blockers. We changed to flecainide 2 mg/kg/day and had no satisfactory response. 
Family history: 2 uncles on the mother side died of sudden death at 25 and 28 years old, mother with normal ECG. 
Father and 2 sisters with type-3 long QT by electrocardiographic pattern (QTc 0.50 – 0.53 respectively), asymptomatic. They are not medicated. 
No history in the father's side of the family. 

We would be grateful if you could give us your diagnostic impression and management to follow. 
Kind regards.