Zero-fluoroscopy catheter ablation of concealed left accessory pathway in a pregnant woman

A 22-year-old woman in the 21st week of her first pregnancy without the history of heart disease was admitted to our department for electrophysiology study because of the documented symptomatic narrow QRS tachycardia. To prevent foetal X-ray exposure, three-dimensional (3D) electroanatomic mapping (EAM) system EnSite/NavX (St. Jude Medical) was used (Figure 1A). During the placement of catheters, we recorded a spontaneous induction of the orthodromic atrioventricular re-entrant tachycardia (AVRT) with the first atrial activation in the distal coronary sinus (Figure 1B), indicating the presence of a left accessory pathway. Transseptal puncture was performed with the aid of intracardiac echocardiography and without fluoroscopy. Radiofrequency ablation in the area of the earliest left atrial activation terminated the AVRT. Figure 1A shows a partial 3D EAM of the left atrium (red dot representing the site of ablation). The intracardiac electrograms at the moment of termination of the AVRT are shown in Figure 1B (marked with asterisk). There were no procedure-related complications. The patient was free of palpitations in the 3-month follow-up, and 24-h ECG monitoring revealed no arrhythmias. According to clinical and ultrasound examination, there were no foetal abnormalities. The full-length version of this report can be viewed at: http://www.escardio.org/Guidelines-&-Education/E-learning/Clinical-cases/Electrophysiology/EP-Case-Reports.