The authors of this study sampled a center in Italy to analyze data concerning 2,169 patients with symptomatic or asymptomatic Wolff-Parkinson-White Syndrome. Each patient included in the study had to undergo electrophysiological study at baseline. The primary endpoints measured during the study were the percentage of patients who experienced either potentially malignant arrhythmias or ventricular fibrillation (VF). Of the patients enrolled, 1,168 (602 asymptomatic) were subject to ablation surgery, while 1,001 (550 asymptomatic) were not. Besides the presence of symptoms, there were no significant clinical or electrophysiological differences between the two groups. After a 22-month median follow-up length, 15 non-ablation patients (1.5%) were found to have experienced VF. Fibrillation was also associated with shorter accessory pathway antegrade refractory period as well as atrial fibrillation initiated by atrioventricular reentrant tachycardia. Presyncope and dizziness were among the most common warning symptoms. Seventy-eight (48 asymptomatic) patients in this group experienced a “malignant” arrhythmia.
Among patients in the ablation group, there were no recorded instances of VF or malignant arrhythmia over the course of the 8-year follow-up and ablation was successful in 98.5% of cases. One patient in the ablation group did experience complications, resulting in a complete heart block. When untreated, patients were more likely to experience complications like VF and arrhythmias than ablation patients. Untreated, asymptomatic patients were also more likely to develop VF than untreated symptomatic patients. At the close of the study, the authors concluded that the prognosis and potential risks of Wolff-Parkinson-White syndrome is not dependent on symptoms. Moreover, they determined that performing catheter ablation after initial electrophysiological testing is beneficial to both the mitigation of risk and the outlook for patients long term.