Accessory pathways in monozygotic twins with different clinical phenotypes: a case report

Abstract Background The atrioventricular reentrant tachycardia (AVRT) is the most common associated with accessory pathways (APs). Although sporadic Wolff-Parkinson-White (WPW) syndrome has been well-described, AP occurrence in identical twins WPW remains rarely reported. Case presentation We report a case of 14-year-old monozygotic twin brothers referred for an electrophysiology (EP) study. Twin A presented recurrent symptomatic narrow complex after exercise, noted 3 years. His 12-lead surface electrocardiogram (ECG) did not show ventricular pre-excitation. However, orthodromic AVRT utilizing concealed right posteroseptal was found and successfully ablated. recur 12 months procedure. B asymptomatic. During his medical examination firefighter volunteerism, ECG showed spontaneous EP study revealed short anterograde midseptal AP, which then eliminated by catheter ablation. no pre-excitation recurrence Conclusions These had right-side almost same place but completely different phenotypes. This clearly illustrates difficulty understanding genetic contribution origin APs. Environmental exposure could play role their clinical presentations electrophysiological properties.