Characterization of high‐power and very‐high‐power short‐duration radiofrequency lesions performed with a new‐generation catheter and a temperature‐control ablation mode

Abstract

Introduction: High-power short-duration (HPSD) has been proposed to shorten procedure times while maintaining efficacy and safety. We evaluated the differences in size and geometry between radiofrequency lesions obtained with this method and conventional ones.Methods and Results: Twenty-eight sets of 10 perpendicular radiofrequency applications were performed with two commercially available catheters: a temperature-controlled HPSD catheter (QDot-Micro) and a conventional powercontrolled catheter (Thermocool SmartTouch) on porcine left ventricle. Different power settings (35, 40, 50, and 90 W), contact force (CF; 10 and 20 g), ablation index (AI; 400 and 550), and application times were combined to create conventional (35-40 W), HPSD (50 W) and very-high-power short-duration (VHPSD; 90 W) lesions, that were cross-sectioned and measured. About 4-s VHPSD lesions were smaller, shallower, and thinner than HPSD performed with the QDot-Micro catheter in any scenario of CF or AI (61 ± 7.8 mm 3 , 6.1 ± 0.3 mm wide, and 2.9 ± 0.1 mm deep with 10 g; 72.2 ± 0.5 mm 3 , 6.8 ± 0.3 mm wide, and 2.9 ± 0.2 mm deep with 20 g).Conventional and HPSD lesions performed with the temperature-controlled catheter were generally bigger, deeper, and wider than the ones obtained with the power-controlled catheter, as well as more consistent in size. This was especially true with the lower CF and AI scenario, while differences were less notable with other setting combinations. Conclusion:VHPSD lesions performed with QDot-Micro catheter were smaller than any other lesions, which is especially attractive for posterior left atrial wall ablation.On the contrary, conventional-powered and HPSD lesions performed with this catheter were equally sized (or even bigger with lower CF and AI objectives), as well as more consistent in size, which would guarantee transmurality in other locations.

Long-Term Durability of High- and Very High-Power Short-Duration PVI by Invasive Remapping: The HPSD Remap Study

“…Although vHPSD ablation results in a different lesion geometry and smaller size compared with conventional lower-power ablation, the depth of the vHPSD applications is mostly sufficient to create transmural lesions in the left atrium. [5][6][7][8] These properties of vHPSD lesions raise a need for decreasing the interlesion distance, verified in a clinical setting by our previous report. 11 The advantages of this novel technique have also translated into clinically meaningful results in previous studies, as evidenced by substantially shorter total procedure, LA ablation, and radiofrequency times compared with ablation with lower power.…”

“…[2][3][4] PVI with high power and short duration (HPSD; >40 W) creates smaller but more uniform lesions compared to low-power long duration ablation, resulting in favorable safety and efficacy. [5][6][7][8][9] Recently, a very HPSD (vHPSD; 90 W, 4 s) technique has been introduced, but initial efficacy results were mostly discouraging regarding first-pass isolation rates, acute reconnection rates, and arrhythmia-free survival. [10][11][12][13][14] We hypothesized that vHPSD PVI could result in similar acute and long-term efficacy as ablation indexguided PVI with 50 W. 11 Therefore, we designed the HPSD Remap study (Efficacy Comparison of High and Very High Power Short Duration Pulmonary Vein Isolation, URL: https://www.clinicaltrials.gov; unique identifier NCT05459831), in which durability of lesions was assessed by a repeat electrophysiology study after an index PVI performed with either a 90-or 50-W power setting.…”

Left ventricular summit premature ventricular contractions treated by venous ethanol infusion: Scar assessment by magnetic resonance imaging

“…10 Interestingly, 2 months after ablation cardiac MRI made it possible to in vivo visualize the depth of the targeted substrate and thus, to understand its inaccessibility to RF energy. 11 The scar produced by ethanol ablation had a limited mass and a homogeneous aspect which are characteristics likely associated with a limited risk of proarrhythmia. 12 It should be highlighted, however, that in the case of absence of any venous branch close to the source of the VA, ethanol infusion is merely impossible thus, demonstrating that this technique cannot be universally adopted.…”

“…Interestingly, 2 months after ablation cardiac MRI made it possible to in vivo visualize the depth of the targeted substrate and thus, to understand its inaccessibility to RF energy 11 . The scar produced by ethanol ablation had a limited mass and a homogeneous aspect which are characteristics likely associated with a limited risk of proarrhythmia 12 …”

Left Ventricular Summit Premature Ventricular Contractions treated by Venous Ethanol Infusion: Scar Assessment by magnetic resonance imaging

“…10 Interestingly, 2 months after ablation cardiac MRI made it possible toin vivo visualize the depth of the targeted substrate and thus, to understand its inaccessibility to RF energy. 11 In addition, the scar produced by ethanol ablation had a limited mass and a homogeneous aspect. These are characteristics likely associated with a limited risk of proarrhythmia.…”