Temperature controlled high power short duration ablation with 90 watts for 4 seconds: Outcome, safety, biophysical characteristics and cranial MRI findings in patients undergoing pulmonary vein isolation

Abstract

Background High power short duration (HPSD) radiofrequency-ablation (RFA) is highly efficient and safe while reducing procedure and RF time in pulmonary vein isolation (PVI). The QDot-catheter is a novel contact-force ablation catheter that allows automated flow and power adjustments depending on the local tissue temperature to maintain a target temperature during 90watts/4seconds lesions. We analysed intraprocedural data and periprocedural safety using the QDot-catheter in patients undergoing PVI for paroxysmal atrial fibrillation (PAF). Methods We included n=48 patients undergoing PVI with the QDot-catheter with a temperature controlled HPSD ablation mode with 90watts/4seconds (TC-HPSD). If focal reconnection occurred besides repeat ablation the ablation mode was changed to 50watts/15seconds (QMode). N=23 patients underwent cerebral MRI to detect silent cerebral lesions. Results Mean RF-time was 8.1+/-2.8min, procedure-duration was 84.5+/-30min. The overall maximal measured catheter-tip temperature was 52.0°C +/- 4.6°C, mean overall applied current was 871mA +/-44mA and over all applied energy was 316J +/-47J. The mean local impedance-drop was 12.1 +/- 2.4 Ohms. During Adenosine challenge n=14 (29%) patients showed dormant conduction. A total of n=24 steam pops were detected in n=18 patients (39.1%), while no pericardial tamponade occurred. No periprocedural thromboembolic complications occurred, while n=4 patients (17.4%) showed silent cerebral lesion. Conclusion TC-HPSD ablation with 90watts/4seconds using the QDot-catheter led to a reduction of procedure and RF time, while no major complications occurred. Despite optimized temperature control and power adjustment steam pops occurred in a rather high number of patients, while none of them lead to tamponade or to clinical or neurological deficits.