Background: Pulmonary vein isolation (PVI) by contiguous, transmural and durable lesions is decisive for ensuring long-term freedom from atrial fibrillation (AF). AF-ablation requires irrigated tip catheters to reduce thromboembolic complications. This precluded temperature-controlled delivery of radiofrequency (RF) energy.

Aim: To evaluate feasibility, acute efficacy and safety of an irrigated, temperature-controlled ablation catheter (DiamondTemp^TM, Medtronic®, DT) for PVI.

Methods: Consecutive patients with AF underwent PVI using the DT catheter combined with high-power short-duration RF-applications. Ablation settings were 1) a catheter-tip temperature limit of 60°C, 2) a temperature-controlled power of 50 W, and 3) an application duration of 10 sec. Primary endpoint was acute PVI, reassessed after a 30 min waiting period. Secondary endpoints included procedural parameters (catheter-tip temperature of 50°C >3 sec, an impedance drop of 5-10 Ω) and the occurrence of serious adverse events. 

Results: 50 consecutive patients [mean age 6612 years, 38 (76%) female, 24 paroxysmal AF (48%)] were included. Median procedure and left atrial dwell time was 89 [68;107] and 63 [52;79] min. Mean number of RF-applications was 5920 per patient, and mean total RF-duration 146 min. Acute PVI was achieved in all patients. Acute PV reconnection within the waiting period occurred in five patients; all reconnected PVs were successfully re-isolated. One major complication occurred. 

Conclusion: In this study, the DT ablation system demonstrated high acute efficacy and safety for PVI.