Temperature-controlled high-power short-duration ablation with 90W for 4s: outcome, safety, biophysical characteristics and cranial MRI findings in patients undergoing pulmonary vein isolation.

Abstract

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 90W/4s lesions. We analysed intraprocedural data and periprocedural safety using the QDot-catheter in patients undergoing PVI for paroxysmal atrial fibrillation (PAF). We included n = 48 patients undergoing PVI with the QDot-catheter with a temperature-controlled HPSD ablation mode with 90W/4s (TC-HPSD). If focal reconnection occurred besides repeat ablation, the ablation mode was changed to 50W/15s (QMode). N = 23 patients underwent cerebral MRI to detect silent cerebral lesions. Mean RF time was 8.1 ± 2.8min, and 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 overall 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. TC-HPSD ablation with 90W/4s 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 leads to tamponade or to clinical or neurological deficits.