Coronary microcatheter mapping of coronary arteries during radiofrequency ablation in children

Introduction: Radiofrequency catheter ablation (RFCA) is a safe and effective treatment option for children with refractory supraventricular tachycardias. RFCA of right-sided accessory pathways (APs) continues to be challenging, resulting in lower success rates and higher recurrence rates. One of the reasons for a prolonged or failed procedure is mapping error and changes in cardiac anatomy. The right coronary artery (RCA) runs along the ventricular aspect of the right epicardial atrioventricular groove, and RCA mapping had been reported facilitating difficult right-sided AP RFCA in the pediatric population. We reported that microcatheter-assisted mapping during RFCA can improve localization of right-sided and some left-sided APs particularly in children with congenital heart disease. Methods: This technique was used in seven patients with a mean age of 15.3±1.6 years and a mean weight of 52.6±6.5 kg. Five patients (71%) had manifest preexcitation on surface electrocardiogram, and two patients had a concealed AP. In two of them, there were single ventricle anatomies. In the other two patients, venous access problem to the heart and enormous cardiac hypertrophy were the major problems. In the remaining three patients with normal cardiac anatomy, RCA mapping was used because a standard procedure was not successful. Previous RFCA ablation was not successful in two patients. Either a 150-cm eight-electrode pair (2-6-2 mm, 2.5 French) or a four-electrode pair (2-6-2 mm, 2.3 French) microcatheter (2.3 French octapolar microcatheter) was used. Results: Average time of the multielectrode RCA mapping was 42±14.5 min. All eight (100%) APs were successfully ablated. No complications occurred. Conclusions: Microcatheter-assisted coronary artery mapping during RFCA is a useful adjunctive mapping technique in children with difficult to map right-sided APs and patients with APs who has complex cardiovascular anomalies.