[QTc variability. Is a single measurement of QT/QTc interval enough to perform risk stratification and therapeutic decisions in a patient with long QT syndrome?].

We described a case of 30 year-old woman with episodes of syncope primarily diagnosed as epilepsy, and finally recognised as long QT syndrome. Based on QTc prolongation > 600 ms in series of electrocardiograms and Holter monitoring the patient was implanted with cardioverter-defibrillator (ICD). During follow-up many appropriate ICD shocks due to ventricular fibrillation occurred.