Presence of ventricular dyssynchrony and haemodynamic impact of right ventricular pacing in adults with repaired Tetralogy of Fallot and right bundle branch block

42 adults with surgically repaired Tetralogy of Fallot (TOF) and right bundle branch block (RBBB). A subgroup of 10 patients had NYHA class II or III and echocardiographic signs of RV dysfunction. 30 healthy matched control subjects were included for comparison.

Atrio-synchronized right ventricular pacing at four different sites (infundibulum, apex, septal, and lateral walls) during an acute haemodynamic study.

Spontaneous rhythm (for the pacing study); healthy matched controls (for the echocardiographic dyssynchrony comparison).

Intra-RV dyssynchrony (IRVD) and intra-left ventricular dyssynchrony (ILVD) by echocardiography; cardiac index measured by thermodilution and QRS duration during pacing.surrogate