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Introduction: Lesion size index (LSI) was introduced with the use of Tacticath™ and as a surrogate of lesion quality. The metric used to achieve the predetermined values involves combined information of contact force (CF), power and radiofrequency time. Rapid atrial pacing (RAP) and high‐frequency low‐tidal volume ventilation (HFLTV) independently or in combination improve catheter stability and CF and quality of lesions. Data of the impact of body weight adjusted HFLTV ventilation strategy associated with RAP in the lesion metrics still lacking. The study aimed to compare the results of high‐power short‐duration (HPSD) atrial fibrillation ablation using simultaneous weight adjusted HFLTV and RAP and standard ventilation (SV) protocol. Methods: Prospective, nonrandomized study with 136 patients undergoing de novo ablation divided into two groups; 70 in RAP (100 ppm) + HFLTV with 4 mL/kg of tidal volume and 25 breaths/min (group A) and 66 patients with SV in intrinsic sinus rhythm (group B). Ablation using 50 W, CF of 5–10 g/10–20 g and 40 mL/minute flow rate on the posterior and anterior left atrial wall, respectively. Results: No procedure‐related complications. Group A: Mean LSI points 70 ± 16.5, mean total lower LSI 3.4 ± 0.5, mean total higher LSI 8.2 ± 0.4 and mean total LSI 5.6 ± 0.6. Anterior and posterior wall mean total LSI was 6.0 ± 0.4 and 4.2 ± 0.3, respectively. Mean local impedance drop (LID) points were 118.8 ± 28.4, mean LID index (%) 12.9 ± 1.5, and mean LID < 12% points 55.9 ± 23.8. Anterior and posterior wall mean total LID index were 13.6 ± 2.0 and 11.9 ± 1.7, respectively. Recurrence in 11 (15.7%) patients. Group B: Mean LSI points 56 ± 2.7, mean total lower LSI 2.9 ± 0.7, mean total higher LSI 6.9 ± 0.9, and mean total LSI 4.8 ± 0.8. Anterior and posterior wall mean total LSI was 5.1 ± 0.3 and 3.5 ± 0.5, respectively. Mean LID points were 111.4 ± 21.5, mean LID index (%) 11.4 ± 1.2, and mean LID < 12% points 54.9 ± 25.2. Anterior and posterior wall mean total LID index were 11.8 ± 1.9 and 10.3 ± 1.7, respectively. Recurrence in 14 (21.2%) patients. Mean follow up was 15.2 ± 4.4 months. Conclusion: Weight adjusted HFLTV ventilation with RAP HPSD ablation produced lower recurrence rate and better LSI and LID parameters in comparison to SV and intrinsic sinus rhythm. [ABSTRACT FROM AUTHOR]

Background: The study focused to identify markers of success in patients submitted to high-power short-duration (HPSD) atrial fibrillation (AF) ablation with contact force (CF) catheter. Methods: Prospective, observational study with 227 patients with first AF ablation in sinus rhythm using 50W of power and divided in two groups; success and failure according to absence or presence of AF related arrhythmias, respectively. Results: Success observed in 188 and failure in 39 patients, respectively. Median follow-up was 31±21.1 months. Left atrial time was shorter in success than in recurrence group (69.6±23.1 vs 83.2±21.2 min, p=0.008) as in total procedure time (80.1±30.2 vs 98.5±23.3min, (p=0.01). Radiofrequency time was 1,478±321.2 vs 1,888.4±584.1sec (p=0.001) in success and failure groups, respectively. Esophageal warming observed in 58 (30.9%) success and 14 (53.8%) recurrence patients (p=0.01). Higher rate of first-pass isolation observed in success than recurrence, 118 (77.6%) and 15 (50%) (p=0.039), respectively. After ablation heart rate increased from 53.8±9.7 to 66.8±11.6bpm in success and 57±7.7 to 64.4±10.4bpm in recurrence groups (p= 0.001), respectively. Conclusion: HPSD ablation identified that shorter left atrial time, lower luminal esophageal temperature heating, shorter radiofrequency time, higher heart rate increase and first-pass isolation effect were associated with better arrhythmia free-survival rates during follow-up. [ABSTRACT FROM AUTHOR]

Different results are described after atrial fibrillation ablation and multiple predictors of recurrence are well established. Evaluate and analyze if heart rate increase (HRI) during a first atrial fibrillation (AF) ablation with low-power long-duration (LPLD) and subsequently with high-power short-duration (HPSD) can impact. Retrospectively analyzed 340 consecutive patients (pts) undergoing first AF ablation. There were 158 pts in LPLD group: 113 (71.5%) paroxysmal AF with ablation with a power of 30/20 w, on anterior and posterior left atrial (LA) wall, respectively, and contact force of 10–30g for 30 s. There were 182 pts in HPSD group: 106 (58.2%) paroxysmal AF, who underwent ablation with 45/50 w, contact force of 8–15g/10–20g and 35 mL/min flow rate on anterior and posterior left atrial wall, respectively. Median follow-up was 32 ± 16 months. Success was observed in 94 (59.5%) patients in LPLD and 152 (83.5%) in HPSD, in LPLD group we documented a median HRI of 4.3 bpm (8%), compared to preablation heart rate, while a higher HRI in HPSD group of HRI 13.5 bpm (27.2%) was noted. Heart rate increase was associated with a higher success rate in both ablation techniques and independently showed an important impact on the success rate after AF ablation. HPSD compared to LPLD showed a higher proportion of HRI and also demonstrated a superiority in maintaining sinus rhythm at a long-term follow-up. [ABSTRACT FROM AUTHOR]