Background Radiofrequency ablation is a commonly used to treat atrial fibrillation (AF) and complex atrial tachycardia (AT). High power short duration ablation has been suggested as a method to reduce procedure times whilst creating safe and lasting lesions.

Methods and Results  We performed lesion size index (LSI) guided 50 Watt point-by-point ablation in 108 consecutive patients using a contact force-sensing catheter (TactiCath; Abbott). Target LSI at the anterior left atrium (LA) was 5.0 and 4.5 at the posterior LA and at total right atrium (RA).

Altogether 9.567 RF lesions were created. RF time per lesion was 14.3±0.1 sec with a LSI of 4.9±0.01 and a CF of 13.4±0.1 g. RF time per lesion at the anterior wall of LA was 15.9±0.2 sec and 13 ± 0.2 sec at the posterior wall of LA and the right atrium. CF at the anterior wall of LA was 13.8±0.2 g and 12.2±0.4 g at the posterior wall of LA and at RA. We observed FTI values between 36 and 310 gs.

Procedure and RF times were 117±5 min and 16.6±0.8 min, respectively. For PVI alone, procedure duration was 99±3 min with a RF time of 15±0.6 min. No audible steam pops occurred. No pericardial effusion was observed. After a 6-months follow-up no adverse events were reported and 83% of patients had no arrhythmia recurrence.

Conclusion LSI guided 50 Watt ablation is effective and safe with high acute success rates. Procedure and ablation times were short. Preliminary 6 months recurrence rates are very low.