Noninvasive Risk Stratification Techniques in Pediatric Patients with Ventricular Preexcitation

BACKGROUND: Individuals with ventricular preexcitation (VP) are known to have an increased risk of sudden death. This risk has been associated with conduction properties of the accessory pathway. METHODS: Patients with VP underwent risk stratification through the use of exercise and transesophageal testing. All patients were initially screened with exercise testing and those with preexcitation throughout exercise went on to have transesophageal testing. Patients who demonstrated high-risk pathway characteristics by transesophageal testing or developed clinical indications for an electrophysiology (EP) study underwent ablation. This stepwise risk stratification technique was evaluated for the ability to avoid the need for intracardiac EP study. Patients stratified as low risk were contacted for follow-up. RESULTS: One hundred and twenty-nine exercise studies were performed in 127 patients. Thirty-five of 129 exercise studies demonstrated accessory pathway block during exercise. Twenty-seven of 35 underwent no additional testing. Sixty-six patients underwent transesophageal testing. Forty-nine of 66 patients demonstrated low-risk pathway characteristics and 40 of 49 underwent no further testing. In total, 68 of 129 (53%) patients avoided the need for intracardiac EP study and ablation. A noncardiac indication for the initial diagnostic electrocardiogram was associated with lower likelihood of intracardiac EP study. None of the patients stratified as low risk had additional invasive procedures or life-threatening arrhythmias upon follow-up. CONCLUSIONS: Successful risk stratification of pediatric patients with VP is possible through the use of exercise and transesophageal testing. In this patient population, half of the patients were able to avoid an intracardiac EP study.