LAUSR

It can be assumed that cardiac resynchronization therapy can lead to cardiac remodeling; experimental animal studies even show a positive impact on a cellular level. Introduction Many patients with corrected tetralogy of Fallot (TOF) suffer from right ventricular (RV) dysfunction during long-term follow-up. Besides a chronic pressure or volume overload caused by pulmonary regurgitation or stenosis, electromechanical dyssynchrony due to right bundle branch block (RBBB), may represent an incompletely understood cause for RV dysfunction. Hui and colleagues noted a dyssynchrony in 93% of pediatric patients after repair of the TOF. In these patients a pulmonary valve replacement may not be sufficient for cardiac remodeling. To date there are few data on RV cardiac resynchronization therapy (CRT) in patients with diminished RV function. Janou sek and colleagues showed a positive impact of the atrial synchronized RV free wall pacing regarding the QRS width and RV function. Resynchronization was achieved by optimal fusion of the pacing-induced depolarization wave with the spontaneous ventricular activation via the atrioventricular node and native cardiac conduction system, resulting in the narrowest QRS complex and elevation of the blood pressure. They could demonstrate that CRT decreases the contraction delay between RV septum and free wall and leads to a better contraction efficiency and systolic output. To date there are no data concerning the impact of improved RV function on the left ventricular (LV) function/remodeling.