Optimisation of Catheter Navigation With As Low As Reasonable Achievable Fluoroscopy for Amelioration of Ablation Success in Patients With SupraVentricular Tachycardia (ALARA-SVT)

Aim of the current Randomized Clinical Study is to assess the safety and efficiency in supraventricular tachycardia ablations of the CE-certified (since 2013) CartoUnivuTM module (Biosense Webster, Diamond Bar, USA), allowing a seamless combination of a fluoro Image and Carto® 3 System maps into a single view. It helps reduce fluoroscopy levels - consistent with the ALARA principle of reducing exposure for physicians, staff and patients to as low as reasonably achievable. The UnivuTM technology will be compared in a randomized manner to the conventional radiofrequency (RF) ablation.

Patients with symptomatic supraventricular tachycardia (SVT) will be included, more specifically patients with atrioventricular nodal re-entrant tachycardia (AVRNT), atrioventricular re-entrant tachycardia (AVRT) and typical atrial flutter (TAF). Current ablative treatment consists in destroying small areas of myocardial tissue or conduction system, or both, that are critical to the initiation or maintenance of the arrhythmia (slow pathway Ablation in the case of AVRNT, anomalous extra nodal connections between the atrium and ventricle along the atrioventricular groove in AVRT and cavo-tricuspid isthmus in the case of TAF).

However, SVT ablations without a 3D navigation system have a certain fluoroscopy time and radiation exposure, respectively. Prolonged fluoroscopy and radiation exposure during ablation may potentially cause an increase in the lifetime risk of fatal malignancy.

In a 1-year follow-up the arrhythmia recurrence rate without anti-arrhythmic drugs will be assessed using 7-day holter recording in 60 patients undergoing CartoUnivuTM guided SVT ablation (group A) vs. 60 patients undergoing conventional RF-catheter ablation (without CartoUnivuTM, group B).

All patients will stop anti-arrhythmic drugs at least 1 week before the date of ablation. Each patient will undergo transthoracal echocardiography (TTE) before the intervention. In case transseptal is needed, heparin will be administered after successful transseptal puncture with an activated clotting time (ACT)-target ≥325 sec.