Background
Very high-power short-duration (VHPSD) ablation has been proposed to produce shallower lesions due to a predominance of resistive over conductive heating, potentially reducing collateral tissue injury. However, in vivo data on luminal esophageal temperature (LET) during VHPSD pulmonary vein isolation (PVI) remain limited.
Methods
A total of 107 consecutive patients (62 ± 10 years; 75 male; 88 with paroxysmal atrial fibrillation) underwent PVI using VHPSD (90 W / 4 s) at the posterior wall and high-power short-duration (HPSD; 50 W, ablation index 450) at the anterior wall. LET was continuously monitored during the procedure, and all sites with LET elevation ≥39°C were analyzed.
Results
LET ≥39°C occurred in 41 patients (38.3%), with a mean peak LET of 40.05 ± 0.99°C. The mean time to peak LET was 13.86 ± 6.21 seconds, while temperature returned to within 1°C of baseline after 65.43 ± 19.66 seconds following cessation of radiofrequency (RF) delivery. LET elevations ≥39°C occurred at distances of 3.76 ± 1.73 mm in the anteroposterior (AP) view and 2.83 ± 1.10 mm in the left anterior oblique (LAO) view from the temperature sensors. Notably, 89% of sites with LET ≥39°C were associated with the left inferior pulmonary veins (PV).
Conclusion
VHPSD ablation is associated with clinically relevant increases in LET, particularly at the inferior pulmonary veins. Peak temperature occurs after completion of RF delivery, limiting real-time modulation of application duration. Given the prolonged temperature decay, rapid adjacent RF applications should be avoided. LET monitoring should be considered during VHPSD ablation.
