51W 4-second temperature-controlled ablation with QMode Plus had higher first-pass SVC isolation (92% vs 80%), shorter procedure time, and less mild PN injury (2% vs 13%).
Does 51W 4-second temperature-controlled ablation using the QMode Plus algorithm improve procedural efficiency and safety compared to standard power-controlled ablation for SVC isolation in patients with AF?
High-power (51W) 4-second temperature-controlled ablation for SVC isolation is safe and efficient, reducing procedure time and potentially lowering the risk of mild phrenic nerve injury compared to standard power-controlled ablation.
Absolute Event Rate: 0% vs 0%
Abstract Background Superior vena cava (SVC) isolation can be challenging due to the proximity of the lesion to the phrenic nerve (PN) and sinus node (SN), making the optimal ablation strategy uncertain. A recently developed high-power, short-duration radiofrequency (RF) delivery method can create shallower and wider lesions compared to standard ablation. The QMode Plus algorithm provides 4-second intelligent temperature-controlled ablation with a power greater than 50W (Ref). Aim To test the hypothesis that 51W 4-second temperature-controlled ablation using the QMode Plus algorithm simplifies the procedure and provides optimal SVC isolation. Methods We studied 96 consecutive patients with atrial fibrillation (AF) who underwent SVC isolation (age: 70±7 years old; male: 68%; paroxysmal AF: 46%). The ablation strategy comprised three steps: (1) a local activation time map of the SVC and right atrium (RA) during sinus rhythm was created to identify the SN breakout site; (2) high-current pacing along the lateral portion of the RA-SVC junction was performed to locate the area of PN stimulation (PNS); and (3) circumferential RF ablation with a 4mm inter-lesion distance was performed, starting 10mm above the SN breakout site. In the first 46 consecutive patients, an STSF ablation catheter was used for power-controlled ablation at 25-30W with a target AI of 350 (Control group). In the latter 50 consecutive patients, a QDOT MICRO catheter was used with the QMode Plus algorithm for 51W 4-second temperature-controlled ablation (QMode+ group) (Figure). Results Baseline characteristics, including age, gender, and AF type, did not differ between the two groups. SVC isolation was achieved in all patients, with first-pass success in 46 patients (92%) in the QMode+ group and 37 patients (80%) in the Control group (p=0.14). Procedure time and RF delivery time were significantly shorter in the QMode+ group than in the Control group. A detailed comparison of the outcomes of SVC ablation between the two groups is summarised in Table. No SN injury or PN palsy was observed in either group. Asymptomatic transient mild PN injury occurred in one patient (2%) in the QMode+ group and in six patients (13%) in the Control group (p=0.05), as demonstrated by right diaphragmatic elevation exceeding half the height of one vertebra on a chest X-ray taken one day post-procedure. Conclusion The 51W 4-second temperature-controlled ablation using the QMode Plus algorithm may be a simple, safe, and efficient approach for SVC isolation.
Morishima et al. (Sat,) reported a other. 51W 4-second temperature-controlled ablation with QMode Plus had higher first-pass SVC isolation (92% vs 80%), shorter procedure time, and less mild PN injury (2% vs 13%).