LAUSR

Background: To investigate the clinical features of preexcitation-induced dilated cardiomyopathy in infants and evaluate safety and efficacy of radiofrequency ablation (RFCA) in these patients. Methods: This study included 10 infants (4 males and 6 females) with mean age of 6.78±3.14 months, mean weight of 8.11±1.71 kg, and mean left ventricular ejection fraction (LVEF) was 32.6±10.34%. Tachycardiomyopathy has been excluded and all patients were refractory to the drugs. All of these 10 patients underwent RFCA. Results: All the accessory pathways in these patients were located on right free wall and the acute success rate was 100%. No complication associated with the procedure occurred. In one case preexcitation recurred and was ablated successfully during the second attempt. There were 3 patients with mild cardiac dysfunction (LVEF, 40≤LVEF<50%), 3 with moderate (30≤LVEF<40%), and 4 with severe cardiac dysfunction (LVEF<30%, the ages were 3, 6, 7, and 10 months, respectively). The time for LVEF normalization was 1 week, 1 to 3 months, and ≥3 months, respectively. In 3 of the 4 severe cardiac dysfunction patients, the LVEF normalized at 3, 6, and 12 months after ablation, the LVEF of the remaining case did not recover at 3 months and is still being followed. Conclusions: Ventricular preexcitation could lead to severe cardiac dysfunction during infancy. RFCA may be a safe and effective treatment option in right free wall accessory pathways, even in infants with cardiac dysfunction. Cases of more severe cardiac dysfunction might require a longer time for LVEF recovery after RFCA.