Ventricular Tachycardia in Repaired Tetralogy of Fallot

Ventricular tachycardia in repaired Tetralogy of Fallot is associated with significant morbidity and mortality. The dominant substrate of ventricular tachycardia in repaired Tetralogy of Fallot are slow conducting anatomical isthmuses in the right ventricular outflow tract. The anatomical isthmuses in repaired Tetralogy of Fallot are the result of the malformation itself or the result of the correction. In this thesis is demonstrated that radiofrequency catheter ablation of anatomical isthmus related ventricular tachycardia can be considered curative and prevent ICD implantation in patients with a preserved cardiac function. Risk stratification for ventricular tachycardia in patients with repaired Tetralogy of Fallot has been difficult. In this thesis is demonstrated that electroanatomical mapping in patients with repaired Tetralogy of Fallot can be used to assess the presence and properties of the anatomical isthmuses in order to perform individualized risk stratification. Further, in this thesis, patients with repaired Tetralogy of Fallot and a right bundle branch block with a QRS duration of ≥150 milliseconds have a blocked or slow conducting anatomical isthmus and should undergo invasive electroanatomical mapping to differentiate between a slow conducting or blocked anatomical isthmus.