Patient selection and ablation procedure
Sixty-one consecutive patients addressed for typical RAFl ablation were prospectively included in this study from September 2017 to March 2019. These patients were enrolled in five French centersO. At baseline, ECG showed either a common flutter or sinus rhythm (SR). Exclusion criteria were previous right atrial surgery, baseline PR interval > 240 ms or right atrial or ventricular pacing requirement with permanent pacemaker. For all patients, the standard procedure was performed with CTI block confirmation as described below. The single catheter approach was evaluated at the same time with surface ECG PR measurement at baseline for patients in SR or immediately after SR recovery if patient was in flutter at baseline. PR interval was then also measured when CTI block was confirmed with the standard approach (2 or 3 catheters).