Efficacy of pharmacological treatment and genetic characterization in early diagnosed patients affected by long QT syndrome with impaired AV conduction.

The coexistence of QT prolongation and impaired atrioventricular (AV) conduction with torsade de pointes ventricular tachycardia (TdPVT) is a rare malignant variant of the long QT syndrome (LQTS). The purpose of this study was to examine the clinical presentation, the genetic background and the outcome of a cohort of 7 unrelated patients (4M/3F), all medically treated, affected by LQTS and impaired AV conduction. The possibility of treating this very severe form of LQTS pharmacologically overcomes the significant disadvantages of ICD implantation in young infants, namely, implantation difficulties, prolonged ICD protection with a consequent greater incidence of inappropriate shocks, and potentially more severe psychological problems. Furthermore, genetic familial analysis may indicate treatment in high-risk but yet asymptomatic children.