Impact of weight adjusted high frequency low tidal volume ventilation and atrial pacing in lesion metrics in high-power short-duration ablation: Results of a pilot study.

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.

Incidental parasympathetic cardiac denervation during atrial fibrillation ablation using high power short duration: a marker of long-term success.

BACKGROUND: There are multiple factors in both technique and substrate that lead to recurrence of atrial fibrillation after ablation. We sought to examine whether the degree of heart rate increase (HRI) caused by concurrent high-power-short-duration (HPSD) incidental parasympathetic denervation during AF ablation predicts long term success. Between December 2018 and December 2021, prospectively enrolled 214 patients who presented in sinus rhythm at AF ablation. Used 50 W of power and contact force (CF) of 5-15 g and 10-20 g at a flow rate of 40 mL/min on the anterior and posterior left atrial walls, respectively. RESULTS: Males were 143 (66.8%) and paroxysmal was 124 (57.9%) patients. Mean age 61.1 ± 12.3 years and follow-up time was 32.8 ± 13.2 months. Arrhythmia occurred after 90 days in 39 (18.2%) patients, 19 (48.7%) from the paroxysmal and 20 (51.3%) from the persistent AF patients. Recurrence group showed a lower HRI from a mean of 57 ± 7.7 to 64.4 ± 10.4 bpm (12.3%) while in success group HRI was from 53.8 ± 9.7 to 66.8 ± 11.6 bpm [(24.2%) p = 0.04]. We divided HRI in 3 percentiles of ≤ 8%, > 8 ≤ 37% and > 37%. A predictor of recurrence was identified in those in the first (< 8%, p = 0.006) and a predictor of success in the later (> 37%, p = 0.01) HRI percentile. CONCLUSION: Atrial fibrillation ablation with HPSD incidental cardiac parasympathetic denervation identified that patients with lower heart rate increase are prone to recurrence while those with higher heart rate increase had higher maintenance of sinus rhythm at a long-term follow-up.

Comparison between weight-adjusted, high-frequency, low-tidal-volume ventilation and atrial pacing with normal ventilation in high-power, short-duration atrial fibrillation ablation: Results of a pilot study.

Background: Better contact force (CF) and catheter stability (CS) during atrial fibrillation (AF) ablation are associated with higher success rate. Changes in CF and CS are observed during respiratory movements and cardiac contraction. Previous studies have suggested that rapid atrial pacing (RAP) and high-frequency, low-tidal-volume ventilation (HFLTV) independently or in combination improve CS and CF and quality of lesions. Data from a body weight-adjusted HFLTV strategy associated with RAP in AF high-power, short-duration (HPSD) ablation are still lacking. Objective: This study aimed to compare the results of HPSD AF ablation using simultaneous weight-adjusted HFLTV and RAP and standard ventilation (SV) protocol. Methods: This was a prospective, nonrandomized study with 136 patients undergoing de novo ablation were divided into 2 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). The ablation used 50 W, CF of 5 to 10 g and 10 to 20 g, and 40 mL/min flow rate on the posterior and anterior left atrial walls, respectively. Results: There were no procedure-related complications. In group A, left atrial and total ablation times were 53.5 ± 8.3 minutes and 67.4 ± 10.1 minutes, respectively. Radiofrequency time was 19.7 ± 5.7 minutes, radioscopy time was 3.4 ± 1.8 minutes, 62 (88.6%) patients had first-pass isolation, 23 (33.3%) patients had elevation of luminal esophageal temperature, and 7 (10%) patients had recurrence. In group B, left atrial time was 56.7 ± 10.8 minutes, total ablation time was 72.4 ± 11.5 minutes, radiofrequency time was 22.4 ± 6.2 minutes, radioscopy time was 3.6 ± 3 minutes, 58 (87.9%) patients had first-pass isolation, and 20 (30.3%) patients had luminal esophageal temperature elevation. Conclusion: Weight-adjusted HFLTV with RAP in comparison with SV and intrinsic sinus rhythm in HPSD ablation is safe with no CO2 retention. The approach produced significantly reduced radiofrequency, left atrial, and total ablation times and better CF and local impedance drop indexes.

Is Age Associated with Complications of Atrial Fibrillation Catheter Ablation?

Abstract Background Atrial fibrillation (AF) is the most frequent arrhythmia, and its prevalence increases with age. The management of AF in the elderly is challenging, as it is normally associated with comorbidities and frailty. AF catheter ablation (CA) is a safe and superior alternative to antiarrhythmic drugs (AADs) for the maintenance of sinus rhythm. Objectives To evaluate the rate of complications associated with CA for AF across different age groups. Methods A retrospective analysis of 219 patients who underwent CA for AF between 2016 and 2020 were divided into 3 age groups: less than 60 years, 60 to 70 years, and > 70 years. All the included patients underwent radiofrequency ablation using an electroanatomic mapping system. Categorical variables were evaluated with chi-square and Fisher's test, and continuous variables were evaluated by Kruskal-Wallis and post-hoc Tamhane's T2. P values less than 0.05 were considered significant. Results We found an overall total complication rate of 4.6%. The total complication rate was 3.3% in patients < 60 years of age, 5.7% in patients between 60 and 70 years, and 5.2% in patients > 70 years (p = 0.742). No deaths occurred. Conclusion There was no significant difference in the AF CA-related complications when comparing the patients by age group.

Comparison of outcomes with low-power long duration versus high-power short duration of ablation: the role of the acute change in sinus rhythm after the ablation as a predictor of long-term success.

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.

Reduced esophageal heating in high-power short-duration atrial fibrillation ablation in the contact force catheter era.

BACKGROUND:  Atrial fibrillation (AF) ablation is alternative treatment to medical therapy. Most feared complication is atrioesophageal fistula METHODS: Observational, retrospective analysis of consecutive 355 patients undergoing first AF ablation. Low-power long-duration (LPLD) group contained 158 patients, with 121 (76.58%) having paroxysmal AF who underwent ablation with power 20/30W (anterior and posterior left atrial wall), 17 mL/min flow, and a contact force of 10-30 g for 30 s. High-power short-duration group (HPSD) contained 197 patients, with 113 (57.36%) having paroxysmal AF who underwent ablation at 45/50W of power with a contact force of 8-15 g/10-20 g and a 35 mL/min flow rate for 6-8 s on the anterior and the posterior left atrial wall, respectively. Both groups had pulmonary veins isolated and atrial flutter was ablated when needed. For patients not in sinus rhythm, cardioversion was performed before ablation RESULTS: There were no complications. LPLD group: Left atrial time 118.74 min, total 145.32 min, radiofrequency time 4317.99s, X-ray 13.42 min, and elevation of luminal esophageal temperature (LET) in 132 (84.53%) patients. HPSD group: Left atrial time 72.16 min, total 93.76 min, radiofrequency time 1511.29s, X-ray 7.6 min, and LET elevation in only 75 (38.07%) patients. A markedly higher rate of first-pass isolation was observed in HPSD compared to LPLD, 77.16% versus 13.29%, respectively. Recurrence occurred in 64 (40.50%) and 32 (16.24%) in 28.45 and 22.35 months in LPLD and HPSD patients, respectively. In LPLD, 10 patients were submitted to endoscopy, and one (10%) had mild erythema and in HPSD, 13 performed the endoscopy, with two (15.38%) patients showing mild erythema CONCLUSION: HPSD technique compared to the LPLD technique showed significant reduced radiofrequency and fluoroscopy times, higher rate of first-pass isolation, lower recurrence rate, and esophageal temperature elevation and may also have a protective effect avoiding incidental esophageal injury due to these findings.

Changes and impacts in early recurrences after atrial fibrillation ablation in contact force era: comparison of high-power short-duration with conventional technique-FIRST experience data.

BACKGROUND OR PURPOSE: Different atrial tachyarrhythmias (AT) may be seen during follow-up after atrial fibrillation ablation. Evaluate and analyze characteristics and management of AT following first atrial fibrillation (AF) ablation with high-power short-duration (HPSD) comparing to low-power long-duration (LPLD) and its impact on late outcome. METHODS: Observational, retrospective study, 144 patients submitted to HPSD and LPLD ablation. HPSD with 71 and LPLD with 73 patients and no major clinical differences between the two groups. RESULTS: AT occurred in 60 patients (41.67%) in entire follow-up. HPSD 22 patients had AT: 13 during blanking period (BP) and 9 after that. LPLD: 38 patients with AT, 14 during BP and 24 after that. During BP, HPSD showed high rate of atrial flutter/tachycardia in 9 (69.23) of 13 and LPLD 4 (28.57%) of 14 patients. At 12 months' follow-up, 62 (87.32%) of 71 HPSD patients were in sinus rhythm comparing to 49 (67.12%) of 73 patients in LPLD. CONCLUSIONS: HPSD ablation produced higher rates of early than late recurrence comparing to LPLD. Regular tachyarrhythmias were most common arrhythmia during BP with HPSD ablation and AF in LPLD. HPSD compared to LPLD showed a superiority in maintaining sinus rhythm at 12 months.

Long-Term Follow-Up of Cardioneuroablation to Treat Second-Degree Block After Slow Pathway Ablation.

We present the long-term follow-up of a 31-year-old woman who underwent cardioneuroablation (for atrioventricular (AV) block. Slow pathway ablation was performed in September 2017 with normal follow-up until April 2018, when the patient started noticing symptoms of palpitations at rest, and the electrocardiogram showed a Mobitz I AV block. A cardiac stress test and 24-h Holter monitoring demonstrated first- and second-degree block and normal AV conduction during times of higher heart rate. (Level of Difficulty: Advanced.).

Comparison of high-power short-duration (HPSD) ablation of atrial fibrillation using a contact force-sensing catheter and conventional technique: Initial results.

INTRODUCTION: Atrial fibrillation (AFib) ablation is alternative treatment to drugs. Literature suggests that use of contact force (CF) catheter with higher power for short periods is effective and safe. METHODS/RESULTS: Retrospectively analyzed 76 patients undergoing the first ablation. Third five patients-group A: 27 (77%) paroxysmal AFib (PAFib) and 8 (23%) persistent AFib (PersAFib) who underwent ablation at the power of 30 W-17 mL/minute flow with a CF of 10-30 g for 30 seconds. Fourty one patients-group B: 28 (68.3%) PAFib and 13 (31.70%) PersAFib underwent ablation using 45 W on posterior wall with CF of 8/15 g, as well as 50-W anterior wall with CF of 10/20 g-35 mL/minute flow for 6 seconds. Pulmonary vein isolation in both groups and ablated. For patients not in the sinus, we performed cardioversion before ablation. No complications. Group A: Left atrial time 110 ± 29 minutes, total 148 ± 33.6 minutes, radiofrequency time (RF) 4558 ± 1998 seconds, X-ray 8.5 ± 3.5 minutes, and elevation of esophageal temperature (ET) in 26 (74.3%). group B: Left atrial time 70.7 ± 18.5 minutes ( P < .00001), total 106 ± 23 minutes ( P < .00001), RF 1909 ± 675.8 seconds ( P < .00001), X-ray 8.8 ± 6.6 minutes ( P = .221) and elevation of ET in 21 (51.20% - P = .0578). In 6 and 12 months follow-up, we had 9 (25.71%) and 11 (31.42%) recurrences in group A and 5 (12.19%) and 7 (17.07%) in group B ( P = .231 at 6 and P = .14 at 12 months), respectively. CONCLUSIONS: HPSD was safe, useful, and efficient compared with CT, and reduced procedural time and total RF time. HPSD may reduce esophageal injury because of lower heating rate and it may reduce the recurrence of atrial tachyarrythmias.

Clinical usefulness of electrophysiologic testing in patients with ventricular tachycardia and chronic chagasic cardiomyopathy treated with amiodarone or sotalol.

INTRODUCTION: This study assessed the role of electrophysiologic testing to identify therapeutic strategies for the treatment of patients with sustained ventricular tachycardia (VT) and chronic chagasic cardiomyopathy treated with amiodarone or sotalol. METHODS AND RESULTS: One hundred fifteen patients [69 men (60%); mean age 52 +/- 10 years] with chagasic cardiomyopathy presenting with symptomatic VT were studied after loading with Class III antiarrhythmic drugs; 78 had a history of sustained VT, and 37 with symptomatic nonsustained VT had sustained VT induced at baseline electrophysiologic study. All but 12 patients also underwent baseline electrophysiologic study. Mean left ventricular ejection fraction was 0.49 +/- 0.14. Based on results of electrophysiologic study after loading with Class III drugs, patients were divided into three groups: group 1 (n = 23) had no sustained VT induced; group 2 (n = 45) had only tolerated sustained VT induced; and group 3 (n = 47) had hemodynamically unstable sustained VT induced. After a mean follow-up of 52 +/- 32 months, total mortality rate was 39.1%; it was significantly higher in group 3 than in groups 2 and 1 [69%, 22.2%, and 26%, respectively, P < 0.0001, hazard ratio (HR) 10.4, 95% confidence interval (CI) 3.8, 21.8]. There was no significant difference in total mortality rate between groups 1 and 2 (P = 0.40, HR 1.5, 95% CI 0.75, 4.58). Cardiac mortality and sudden cardiac death rates also were higher in group 3 patients. CONCLUSION: In patients with chagasic cardiomyopathy and sustained VT, electrophysiologic testing can predict long-term efficacy of Class III antiarrhythmic drugs. This may help in the selection of patients for implantable cardioverter defibrillator therapy.