Introduction: We present the case of a 25 year old pregnant woman, with no medical history, with an on-going pregnancy of 21 weeks, addressed to our clinic for fast-paced palpitations with dyspnea and fatigue, with clinical onset 4 days prior to addmission.

Methods: The resting ECG and Holter EKG monito-ring documented sustained wide complex tachycar-dia alternating with short periods of sinus rhythm. The LBBB appearance together with the inferior axis and V2 transition was suggestive for left ventricular outflow tract ventricular tachycardia. The transthora-cic echocardiogram revealed a normally dimensioned and functional left ventricle, with EF=60%, without any elements of tachycardiomiopathy and normal aortic valve. After informing the patient about the risks and benefits, we performed an electrophysiological study. Based on the activation mapping of the left ventricle, we localized the earliest signal at the base of the left co-ronary aortic cusp. We detected the left coronary artery using electroanatomic mapping, impedance and contrast injection.

Results: By radiofrequency applications at the points with endocavitary activation times of 28-30 ms at the base of the aortic valve left cusp, during ventricular ta-chycardia, we restored the sinus rhythm. There was no recurrence of arrhythmia within 20 minutes of waiting. The procedure was guided by 3D CARTO, with scoping time limited to 24 s and irradiation level of 120 μGy / m², used to place the catheters in the heart. Over the next 5 months the patient maintained the sinus rhythm under no antiarrhytmic drug and delivered a healthy child at term, with no complications.

Conclusions: Catheter ablation of pregnancy-associa-ted ventricular tachycardia is a safe therapeutic option in patients with more than 20 weeks of gestation. The procedure can be performed with minimal radioscopic exposure using 3D mapping equipment.