Objective: We sought to evaluate the hemodynamic benefit and efficacy of cardiac resynchronization therapy (CRT) in Fontan candidates with interventricular dyssynchrony.
Methods: CRT was applied in three patients aged 5 months to 32 years with single ventricle physiology. Diagnoses included double outlet right ventricle in two patients and single right ventricle in one. Two patients had completed a total cavopulmonary connection, whereas the remaining one had a bidirectional Glenn shunt. In all patients, echocardiographic analysis demonstrated the existence of interventricular dyssynchrony and the flow regurgitation from right ventricle to (rudimentary) left ventricle through the ventricular septal defect.
Results: The mean QRS duration decreased from 175±41 to 135±41 msec. Echocardiograpy showed improvement of interventricular dyssynchrony, which accompanied decreased flow regurgitation through the ventricular septal defect. The mean cardiothoracic ratio decreased from 72±5 to 61±6 %. Clinical improvement was seen in all patients, with decrease of diuretics dosage.
Conclusions: CRT resulted in improved interventricular dyssynchrony and clinical status in patients with functional single ventricles. CRT may be a useful adjunct in the treatment of cardiac dysfunction in Fontan candidates, who’s one ventricle has become a damping chamber.