Undergoing Atrial Fibrillation Ablation Research Articles

Impact of Sleep Apnea on Nocturnal Parasympathetic Activity in Atrial Fibrillation Patients After Catheter Ablation - Implications for Heart Rate Variability Analysis.

The impact of sleep apnea (SA) on heart rate variability (HRV) in atrial fibrillation (AF) patients has not been investigated.Methods and Results: Of 94 patients who underwent AF ablation between January 2021 and September 2022, 76 patients who had a nocturnal Holter electrocardiography and polysomnography conducted simultaneously were included in the analysis. A 15-min duration of HRV, as determined by an electrocardiogram during apnea and non-apnea time, were compared between patients with and without AF recurrence at 12 months' postoperatively. Patients had a mean age of 63.4±11.6 years, 14 were female, and 20 had AF recurrence at 12 months' follow-up. The root mean square of the difference between consecutive normal-to-normal intervals (RMSSD, ms) an indicator of a parasympathetic nervous system, was more highly increased in patients with AF recurrence than those without, during both apnea and non-apnea time (apnea time: 16.7±4.5 vs. 13.5±3.3, P=0.03; non-apnea time: 20.9±9.5 vs. 15.5±5.9, P<0.01). However, RMSSD during an apneic state was decreased more than that in a non-apneic state in both groups of patients with and without AF recurrence (AF recurrence group: 16.7±4.5 vs. 20.9±9.5, P<0.01; non-AF recurrence group; 13.5±3.3 vs. 15.5±5.9, P=0.03). Consequently, the effect of AF recurrence on parasympathetic activity was offset by SA. Similar trends were observed for other parasympathetic activity indices; high frequency (HF), logarithm of HF (lnHF) and the percentage of normal-to-normal intervals >50 ms (pNN50). Without considering the influence of SA, the results of nocturnal HRV analysis might be misinterpreted. Caution should be taken when using nocturnal HRV as a predictor of AF recurrence.

Initial real-world data on catheter ablation in patients with persistent atrial fibrillation using the novel lattice-tip focal pulsed-field ablation catheter.

Technological advancements have contributed to the enhanced precision and lesion flexibility in pulsed-field ablation (PFA) by integrating a three-dimensional mapping system combined with a point-by-point ablation strategy. Data regarding the feasibility of this technology remain limited to some clinical trials. This study aims to elucidate initial real-world data on catheter ablation utilizing a lattice-tip focal PFA/radiofrequency ablation (RFA) catheter in patients with persistent atrial fibrillation (AF). Consecutive patients who underwent catheter ablation for persistent AF via the lattice-tip PFA/RFA catheter were enrolled. We evaluated acute procedural data including periprocedural data as well as the clinical follow-up within a 90-day blanking period. In total, 28 patients with persistent AF underwent AF ablation either under general anaesthesia (n = 6) or deep sedation (n = 22). In all patients, pulmonary vein isolation was successfully achieved. Additional linear ablations were conducted in 21 patients (78%) with a combination of successful anterior line (n = 13, 46%) and roof line (n = 19, 68%). The median procedural and fluoroscopic times were 97 (interquartile range, IQR: 80-114) min and 8.5 (IQR: 7.2-9.5) min, respectively. A total of 27 patients (96%) were interviewed during the follow-up within the blanking period, and early recurrent AF was documented in four patients (15%) including one case of recurrent AF during the hospital stay. Neither major nor minor procedural complication occurred. In terms of real-world data, our data confirmed AF ablation feasibility utilizing the lattice-tip focal PFA/RFA catheter in patients with persistent AF.

Heart Failure score and outcomes in patients with preserved ejection fraction after catheter ablation for atrial fibrillation.

Atrial fibrillation (AF) is frequently associated with heart failure with preserved ejection fraction (HFpEF), but the diagnosis and prediction of the outcomes of HFpEF are difficult. Notably, the Heart Failure Association of the European Society of Cardiology proposed the use of the HFA-PEFF score in the diagnosis of HFpEF. This study aimed to assess the prognostic value of the pre- and post-procedural HFA-PEFF scores in patients with preserved ejection fraction (EF) after catheter ablation (CA) for AF. The primary endpoint was a composite of cardiac hospitalization for cardiovascular events and all-cause mortality. The secondary endpoint was AF recurrence. Overall, 354 patients with AF and preserved EF who underwent CA as well as blood tests and transthoracic echocardiography 2weeks before and 6months after CA from January 2018 to December 2019 were retrospectively enrolled in the study. In the 354 participants, univariate analysis showed that the post-procedural HFA-PEFF score was associated with a 3-year risk of the primary endpoint (hazard ratio [HR]=3.73; 95% confidence interval [CI]=2.07-6.73; P<0.001), whereas the pre-procedural HFA-PEFF score was not (HR=1.24, 95% CI=0.82-1.86, P=0.307). Further, the association between the post-procedural HFA-PEFF score and primary endpoint was not modified even after including other relevant variables into the score. Similar to the primary endpoint, the post-procedural HFA-PEFF score was associated with the 3-year risk of AF recurrence (P<0.001). In patients with preserved EF undergoing AF ablation, the HFA-PEFF score at 6months after CA was associated with the primary endpoint and AF recurrence at the 3-year follow-up.

National workflow experience with pulsed field ablation for atrial fibrillation: learning curve, efficiency, and safety.

Recent data on pulsed field ablation (PFA) for atrial fibrillation (AF) ablation suggest a progressive reduction in procedural times. Real-world data regarding the relationship between the learning curve of PFA and clinical outcomes are scarce. The objective was to evaluate the PFA learning curve and its impact on acute outcomes. Consecutive patients undergoing AF ablation with the FARAPULSE™ PFA system were included in a prospective, non-randomized multicenter study. Procedural times were stratified on the operators' learning curve. Comparative analysis of skin-to-skin time was conducted with radiofrequency (RF) and cryoablation (CB) pulmonary vein isolation (PVI) procedures performed by the same operators in the previous year. Among 752 patients, 35.1% were females, and 66.9% had paroxysmal AF; mean age was 62.2 ± 10 years. A total of 62.5% of procedures were performed by operators with > 20 PFA procedures. Both time to PVI (25.6 ± 10 min vs 16.5 ± 8, p < 0.0001) and fluoroscopy time (19.8 ± 8 min vs 15.9 ± 8 min, p = 0.0045) significantly improved after 10 associated with consistent linear trend towards procedural time reduction (R2 0.92-0.68 across various procedural metrics). Current PFA skin-to-skin time was lower than the historical skin-to-skin one in 217 (62.4%) procedures; it was similar in 112 (32.2%) cases and higher than the historical skin-to-skin one in 19 (5.5%). No major complications were reported. In this nationwide multicentric experience, the novel PFA system proved to be fast, safe, and acutely effective in both paroxysmal and persistent AF patients. The learning curve appears to be rapid, as improvements in procedural parameters were observed after only a few procedures. Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA). URL: http://clinicaltrials.gov/ Identifier: NCT05617456.

Sex differences in atrial fibrillation ablation outcomes in patients with heart failure.

There is a lack of data on the impact of sex on the outcomes of patients with heart failure (HF) undergoing atrial fibrillation (AF) ablation. We aimed to analyze the association of sex with outcomes of atrial fibrillation ablation in patients with heart failure. The National Readmissions Database (NRD) was analyzed from 2016 to 2019 to identify patients ≥ 18years old with heart failure (HF) undergoing AF ablation. The outcomes of interest included peri-procedural complications, in-hospital mortality, resource utilization, and unplanned 1-year readmissions. The final cohort was divided into patients with HFrEF and HFpEF and outcomes were compared between males and females in both cohorts. A total of 23,277 patients with HF underwent AF ablation between 2016 and 2019, of which 14,480 had HFrEF and 8,797 had HFpEF. Among patients with HFrEF, 61.6% were males and 38.4% were females whereas, among patients with HFpEF, 35.4% were males and 64.6% were females. On a multivariable-adjusted analysis, in patients with HFrEF, there was no difference in the odds of in-hospital mortality, peri-procedural complications, or 1-year HF-related/AF-related/all-cause readmissions between males and females. In patients with HFpEF, females had a higher risk 1-year HF-related readmissions (adjusted hazards ratio: 1.46; 95% CI: 1.13-1.87; p = 0.01), without any difference in the 1-year AF-related/all-cause readmissions, in-hospital mortality, or peri-procedural complications. Our results show that females with HFrEF undergoing AF ablation have similar outcomes whereas females with HFpEF have higher 1-year HF readmissions with no difference in the other outcomes, compared to males.

Quantitative and qualitative assessment of left atrial cardiomyopathy as well as prediction of atrial fibrillation recurrences upon PVI using machine learning

Abstract Introduction Atrial fibrillation (AF) is one of the most common heart pathologies in daily clinical practice and confers significant mortality and morbidity. However, AF ablation often proves ineffective - even after successful pulmonary vein isolation (PVI). The prediction of PVI failure for the long-term treatment of AF as well as the improved assessment of the underlying substrate appears pivotal. We hypothesize, that ML can be applied to better characterize the substrate and recurrence in AF patients upon PVI. Methods &amp; Results We retrospectively evaluated data from 205 patients that underwent AF ablation between 2019 and 2023, including high-density 3D electroanatomic maps (sinus rhythm), LA rotational angiography, invasive LA hemodynamic measurements (after transseptal passage), echocardiography, 12-lead ECG and laboratory testing. A neuronal net was trained on selected features extracted from those datasets using supervised learning and employed to predict measures of atrial cardiomyopathy and AF recurrence. Patients were 66±1 years old and received first or second pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation with 18% documented recurrences upon a mean follow-up of 23±1months. First, we extensively refined or developed tools for automated P-wave analysis from 12-lead ECGs as well as local LA voltage and volume quantification. Next, LA hemodynamics and volumes were assessed: Mean LA volume as derived from rotational angiography significantly correlated with LA volume index as obtained using echocardiography. Interestingly, LA size showed no correlation with NT-proBNP, LA low voltage or LA hemodynamics. In addition, global (25±2% of total LA area) and local (i.e. anterior, posterior, roof) LA voltage was determined and shown to be an independent predictor of AF recurrence. In our first unselected subset of 136 patients with 2nd PVI for atrial fibrillation, our ML models predicted LA fibrosis (i.e. low voltage regions; Utah stage) from 12-lead ECGs with an accuracy of 90%. Accuracy was 87% for the prediction of AF recurrences from LA pressure and low-voltage regions. In addition, the algorithm predicted AF recurrences from 12-lead SR ECGs obtained before PVI with an accuracy of 91%. Conclusion Artificial neural networks allow to quantitatively and qualitatively predict measures of atrial cardiomyopathy and atrial fibrillation recurrence probability upon complete PVI with high accuracy.Figures

Association between left atrial wall thickness and residual potential after first-pass pulmonary vein isolation using very high-power short-duration ablation in patients with atrial fibrillation

Abstract Background In this study, we evaluated efficacy, efficiency, and safety of pulmonary vein isolation (PVI) applying vHPSD ablation strategy in patients with atrial fibrillation (AF) and explored the association between left atrial wall thickness (LAWT) and the residual potential after first-pass PVI. Methods Between April 2, 2023 and October 6, 2023, drug refractory symptomatic AF patients who underwent AF ablation using vHPSD ablation strategy with QDOT MICRO catheter were prospectively enrolled. All patients took cardiac computed tomography (CT) a day before procedure. Using CT image, LAWT map was created. PV segments were categorized into prespecified 14 segments, and LAWT of each segment, segments with residual potential (RP) after first-pass PVI and early reconnection after 20-minute waiting after PVI were evaluated. Total procedure time, ablation time for PVI, and occurrence of procedure-related complication were collected. Results A total of 40 patients were included (mean age 64 years, 45% of persistent AF). Additional ablation other than PV was performed in 48% of patients, total procedure time was 77 minutes, and total PVI time was 9.9 minutes. With vHPSD PVI, all PVs first pass isolation rate was 60%; in terms of per PV, RSPV first-pass isolation was 88%, followed by LSPV and LIPV 85%, RIPV showed lowest first-pass isolation rate, 75% (Figure A). Most common RP sites was right carina, followed by left carina (Figure A). Compared to historical comparator, vHPSD PVI showed shorter procedure time, shorter ablation time for PVI, with numerically lower but statistically comparable first-pass PVI rate (Figure B). In total 560 PV segments in 40 patients, RSPV anterior, left carina, and right carina showed higher prevalence to be thick PV segments (over 60% of patients), followed by RPSV posterior, LSPV posterior, and RIPV anterior (over 40% of patients). Looking into ablation parameter detail, mean contact force was 10g, mean temperature was 47°C, and mean impedance drop was 8.4Ω. Compared to segments without RP, segments with RP showed thicker mean left atrial wall thickness grades, lower minimum contact force, higher maximum temperature, and lower minimum impedance drop. According to the left atrial wall thickness, thick PV segments showed higher prevalence of RP after first-pass PVI with vHPSD ablation. In segments with LAWT grade 3 or more, the RP rate was 9.1%. This thickness means thicker than 1.5 to 2.0 mm of thickness (Figure C). In 10% of patients (n=4) had audible or tactile steam-pops, visible char was confirmed in 5% of patients (n=2). There were no clinical complications. Conclusion PVI using vHPSD achieved shorter procedure time, shorter ablation time for PVI, and comparable first-pass PVI rate compared to historical comparator using ablation-index guided conventional power ablation. Thick segments had higher chance to have residual potential after first-pass PVI with vHPSD.

Acute clinical outcomes of patients with HFpEF undergoing atrial fibrillation ablation

Abstract Aim Robust data show that atrial fibrillation (AF) ablation can improve left ventricular function and prevent cardiovascular complications in patients with heart failure and reduced ejection fraction. The effectiveness and safety of AF ablation in patients with heart failure and preserved ejection fraction (HFpEF) is less well characterized. Methods We retrospectively analyzed 785 consecutive patients with normal left ventricular function undergoing AF ablation in a high-volume center including 251 with AF and HFpEF. We compared baseline parameters, procedural details and procedural complications by heart failure status. Results Patients with HFpEF (n=251/785) were older (median age 70 years vs. 64 years; p &amp;lt; 0.05) and more frequently female (48.2% vs. 32.2%; p &amp;lt; 0.05) compared to patients without HF. Symptom severity was comparable with a median European Heart Rhythm Association score of 2 in both groups (p &amp;gt; 0.05). Arterial (71.7% vs. 59.7%, p &amp;lt; 0.05), diabetes (16.7% vs. 9.4%, p &amp;lt; 0.05) and dyslipidemia (41.4% vs. 27.2%, p &amp;lt; 0.05) were more common in patients with AF and HFpEF. Acute pulmonary vein isolation (PVI) was achieved in all patients using cryoballoon or radiofrequency energy with similar frequency in both groups (cryoballoon ablation: 37.8% vs. 41.6%; p &amp;gt; 0.05). A subgroup of patients in both groups additionally underwent cavotricuspid isthmus ablation for coexistent atrial flutter (26% vs. 20.7%; p &amp;gt; 0.05). Procedure times (119.4 ± 47.7 min vs. 120.2 ± 48.3 min; p &amp;gt; 0.05) and fluoroscopy times (15.8 ± 10.4 min vs. 15.5 ± 7.1 min; p &amp;gt; 0.05) were comparable. Overall complication rates did not differ (12.7% vs. 10.3%; p &amp;gt; 0.05). While the incidence of pericardial tamponades was slightly higher (2% vs. 0%), other severe and minor complications showed no significant differences, including stroke/transient ischemic attack (TIA; 0.4% vs. 0.6%), major life-threatening bleeding (0% vs. 0.2%), vascular complications (1.6% vs. 2.1%), phrenic nerve palsy (0.8% vs. 1.5%), and pulmonary vein stenosis (0.4 vs. 0%). The mean in-hospital stay for the procedure was 2 days in both groups (p &amp;gt; 0.05). In-hospital recurrence rates were similar (12.4% vs. 17%; p &amp;gt; 0.05), as was the need for electrical cardioversion before discharge (5.6% vs. 6.6%; p &amp;gt; 0.05). Conclusion Patients with HFpEF undergoing AF ablation were older, more frequently female, and have more comorbidities than patients without heart failure. Acute procedural success and acute complication rates appear low. These data encourage randomized evaluations of the safety and efficacy of ablation-based rhythm control therapy in patients with AF and HFpEF.

First clinical experience using a novel 8-spline ultra high-resolution mapping catheter to guide atrial fibrillation ablation

Abstract Background Multielectrode mapping catheters improve the detection of scarred and fibrotic tissue in patients with atrial fibrillation (AF) Recently, a novel multispline mapping catheter with 48 closely spaced microelectrodes has been introduced enabling fast high-resolution electroanatomical mapping. Objective This study sought to report our initial clinical experience with the novel Octaray catheter in patients with AF undergoing index ablation and to compare its impact on mapping and ablation with the 5-spline Pentaray catheter. Methods The study included consecutive patients who underwent index AF ablation using a multipolar mapping catheter and very high-power-short-duration guided ablation (Q4U-AF workflow; QDot; Qmode+; Biosense Webster) in conjunction with a visualized sheath (Vizigo; Biosense Webster). Arrhythmia recurrence was defined as any atrial fibrillation (AF)/ atrial tachycardia (AT) episode lasting &amp;gt; 30 s after a blanking period of 3 months. Results A total number of 183 patients undergoing AF ablation using the Octaray and QDot catheter were compared to a group of 166 matched patients who underwent ablation using Pentary and QDot. Utilization of the Octaray catheter resulted in an increased identification of areas with bipolar low-voltage representing fibrosis/scar or atrial cardiomyopathy (mean amount of left atrial bipolar low-voltage: Octaray 31% vs. Pentaray 18%; p= 0.03) and a higher rate of first-pass isolation (FPI) for the left-sided pulmonary veins (Octaray: FPI rate 73% vs. FPI rate 64% for Pentaray). A significantly higher number of mapping points was acquired using the novel 8-spline mapping catheter (right atrium: Octaray 1936 points vs. Pentaray 903 points; p &amp;lt; 0.001 left atrium: Octaray 5337 points vs. Pentaray 2385 points; p &amp;lt; 0.001). Procedural parameter, radiation time/dosage and acute procedural success were comparable between the two groups. During a mean follow-up of 12 months, the overall procedural success was 86 in the Octaray group vs. 84% in the control group (p=0.9). Conclusion The utilization of the novel Octaray mapping catheter resulted in an improved detection of atrial fibrosis and scar as well as a higher rate of first-pass pulmonary vein isolation. Figure: Institutional Q4U-AF-workflow using a multipolar mapping catheter, the QDot ablation catheter and a visualized sheath. High resolution mapping using the Octaray (A+B) and PentaRay catheter (C+D).

Impact of different ablation strategies during very high power short duration ablation: insights from the multicentric AIR HPSD registry

Abstract Background The very high power short duration ablation by mean of the QDOT Micro catheter was demonstrated to be safe and effective to achieve pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients. Data from large multicentric registries are still lacking. Purpose We sought to investigate whether different ablation approaches may impact procedural outcomes. First, the hybrid approach (Qmode+, 90 W for 4 sec, at the posterior wall of the left atrium and Qmode modality AI-guided at the anterior wall) was compared to the ablation performed exclusively with the Qmode+ modality. Second, we investigated the impact of the type of anesthesia. Methods The AIR HPSD registry is a multicentric real world data registry including patients undergoing AF ablation by mean of the QDOT Micro catheter. The ablation modality (hybrid/ Qmode+) and the type of anesthesia were left to operators’ preference. Results Overall, 330 patients were enrolled, 67% males, 71% had paroxysmal AF, the mean age was 61±11. Pulmonary vein isolation was reached in 100% regardless of the ablation modality or the anesthesia used. As for the first pass isolation (FPI) there was a trend toward higher rates in the hybrid group compared to the Qmode+ group (85% vs 74%, p=0.1). No differences in FPI were found between the general anesthesia/deep sedation group and the conscious sedation group (83% vs 81%, p=0.8), however when considering the Qmode+ group solely, the FPI was significantly higher in the general anesthesia/deep sedation group (84% vs 56%, p=0.006). As for the procedural time, this was significantly shorter in the general anesthesia/deep sedation compared to conscious sedation (82±21 vs 97±35 min, p&amp;lt;0.01), as well as in the Qmode+ group compared to the hybrid group (80±31 vs 102±30 min, p&amp;lt;0.01). Minor complications were observed in 1% of patients with no significant differences between groups. Conclusions The PVI can be safely and effectively obtained with both approaches, hybrid or Qmode+ solely, however the rate of FPI seems higher with the hybrid one. When adopting solely the Qmode+ modality the general anesthesia increases the rate of FPI.

Effectiveness of photoplethysmography-based rhythm monitoring after atrial fibrillation ablation using a smartphone application

Abstract Introduction Recurrence of atrial fibrillation (AF) after AF ablation is frequent. Monitoring recurrence is essential for attributing patient symptoms and for assessing both AF burden and treatment effectiveness. The conventional approach relies on periodic (long-term) electrocardiograms (ECG) and is constrained by limited monitoring time, measurement dispersion, and cost. Furthermore, patients are unable to prioritize measurements based on symptoms. Photoplethysmography (PPG) emerges as a technology that could potentially transform any smartphone into a rhythm monitoring device, thereby mitigating the limitations associated with current practices. Selected applications leveraging this technology have demonstrated excellent usability and accuracy for the detection of AF. However, the effectiveness of PPG-based follow-up remains uncertain. Purpose To compare the effectiveness of digital follow-up utilizing a PPG-based smartphone application with conventional ECG-based follow-up for the detection of atrial arrhythmia recurrence after ablation. Methods Patients undergoing AF ablation were consecutively enrolled and monitored using a 24h-ECG at 3-6-12 months on top of ECGs conducted for clinical indications (conventional follow-up). Additionally, patients were instructed to perform PPG measurements twice daily or whenever symptoms were perceived, over the course of one year (digital follow-up). The primary outcome was recurrence of atrial arrhythmia. Results In total, 96 patients (69% male, mean age 64 [58 – 68] years) performed 39,895 PPG measurements. The compliance rate (n performed/prescribed) was 92.6% for ECG and 78.2% for PPG recordings. After one year follow-up, atrial arrhythmia recurrence was detected by conventional follow-up in 17.9% and in 38.5% of patients by digital follow-up (odds ratio, 3.4; 95% CI: 1.7-7.1). The confidence interval lower limit exceeded the predefined non-inferiority margin (p for non-inferiority &amp;gt; 0.001). Hence, superiority was tested (p for superiority = 0.001). The negative predictive value of digital follow-up for atrial arrhythmia detected with conventional follow-up was 98.3% (95% CI: 90.1-99.9%). Symptoms were reported in 81.1% of PPG-detected atrial arrhythmias and episodes sustained for 3.9 [1.1 – 22.7] hours. Conclusions Among patients with AF ablation, digital PPG-based rhythm monitoring with a smartphone, was non-inferior in the detection of atrial arrhythmia recurrence after ablation. Moreover, the detection of atrial arrhythmia was significantly increased compared to conventional ECG-based monitoring.

Association of superior vena cava isolation with improved outcomes in atrial fibrillation ablation

Abstract Background Pulmonary vein isolation (PVI) is the mainstay in atrial fibrillation (AF) ablation. However, additional arrhythmogenic foci seem to contribute to AF initiation and maintenance. A great proportion of those non-PV foci have been reported to be located in the superior vena cava. Purpose We aimed to investigate the effectiveness of SVC isolation as an adjunctive therapy to PVI isolation. Methods We performed a systematic review of MEDLINE, CENTRAL, and Embase. Inclusion criteria were cohort studies with control group or randomized clinical trials, comparing patients undergoing PVI only and patients undergoing PVI with concurrent SVC isolation, in effects of freedom from atrial tachycardia, need for cardioversion, hospitalization and all-cause mortality. Results A total of 7 studies, incorporating 1.550 patients, were included. The combination of SVC and PVI isolation in patients undergoing AF ablation was more effective than PVI isolation alone (risk ratio = 0.689; 95% confidence interval, 0.505-0.942). In a subgroup analysis, the isolation of SVC after identifying focal potentials demonstrated effectiveness (risk ratio = 0.573; 95% confidence interval, 0.364-0.902), while the isolation of SVC when the focal potentials were induced after isoprotenerol infusion or rapid atrial pacing did not alter the clinical outcomes (risk ratio = 0.798; 95% confidence interval, 0.493, 1.292). Conclusions The outcomes of AF ablation are favorable when additional SVC isolation is conducted. The effect is pronounced when spontaneous SVC potentials are identified.

Evaluation of heart rate variability at 1-month after pulsed field ablation of atrial fibrillation and comparison with radiofrequency ablation

Abstract Background Pulsed Field Ablation (PFA) of atrial fibrillation (AF) is a nonthermal novel ablative modality in which high-voltage electric pulses are delivered to generate a high myocardial tissue-specific cellular death, with negligible consequences on surrounding structures including ganglionated plexi. The impairment of the cardiac autonomic ganglia after AF ablation with radiofrequency (RF) has been associated with an increase in mean heart rate (HR) and a reduction in heart rate variability (HRV) and might influence the long-term success of AF ablation. Little data is available on the effect of PFA on cardiac autonomic nervous function. Purpose The aim of this study is to investigate whether PFA ablation could lead to different values of HR and HRV compared to RF at 1-month post-ablation 24-hour Holter monitoring. Methods Between January to September 2023, we included consecutive patients undergoing AF ablation with PFA. According to our clinical practice, all patients performed a routine 24-hour Holter monitoring at 1-month post-ablation. Consecutive AF patients treated with RF were used as controls. Patients in treatment with antiarrhythmics or with documented recurrences of AF at 1-month post-ablation Holter monitoring were excluded. Results 22 consecutive PFA patients were compared to 22 consecutive RF controls. There were no differences in demographic, clinical and echocardiographic data between the 2 groups (Table 1). At 1-month post-ablation Holter monitoring (Table 2), PFA patients had significant higher values of VarIndex (2.18±0.9 vs 1.47±0.7, p=0.01), ASDNN/5min (52.37±15.93 vs 37.17±12.96, p&amp;lt;0.01), SDANN/5min (116.50±27.97 vs 96.03±28.38, p=0.04), and SD (128.95±31.31 vs 106.30±29.56, p=0.04). There was no difference in minimum HR (47.00±6.59 vs 50.29±10.25, p=0.21), mean HR (67.77±6.63 vs 69.24±9.71, p=0.56), and maximal HR (115.41±18.12 vs 110.81±16.44, p=0.39). Conclusions PFA leads to higher values of HRV parameters (i.e., VarIndex, ASDNN/5min, SDANN/5min, and SD) at 1-month post-ablation compared to RF. These data suggest a higher preservation of cardiac autonomic function with PFA, in contrast to RF. Whether the preservation of cardiac autonomic function with PFA might lead to higher rate of long-term AF recurrences remains to be determined.Table 1Table 2

Acute safety and efficacy of ablation for atrial fibrillation in elderly patients by means of pulsed field ablation

Abstract Background It is well known that age affects the efficacy of pharmacological treatment for atrial fibrillation (AF). Thermal ablation (radiofrequency or cryoballoon) is an established strategy for AF. However, there is no evidence evaluating efficiency, effectiveness, and safety outcomes in elderly patients in the context of the novel pulsed-field ablation (PFA) technology. Purpose We aimed to analyze the efficacy and safety of PFA in elderly (age≥75 years) patients with AF compared to non-elderly (age&amp;lt;75 years) patients with AF. Methods All consecutive patients undergoing AF ablation with the Farapulse system at 10 centers were included. Protocol-directed PVI was delivered using 2000 V with eight applications per vein, that is, four applications each in the basket and flower poses. Additional lesions were performed at the operator’s discretion. Results A total of 851 consecutive patients were included: 83 (9.8%) had ≥75 years (median of 77[75-78] years) whereas 768 (90.2%) had &amp;lt;75 years (median of 62[56-68] years, p&amp;lt;0.0001). Older patients had more comorbidities compared to younger patients (kidney disease: 9.6% vs 1.2%, p&amp;lt;0.0001; chronic obstructive pulmonary disease: 8.4% vs 3%, p=0.021; cancer history: 18.1% vs 6.1%, p=0.0004; hypertension: 61.4% vs 43.8%, p=0.002), whereas they exhibited a higher LVEF (60±6% vs 57±8%, p=0.0243). No differences between older and younger patients were found in terms of underlying AF type (paroxysmal AF: 66.3% vs 68.9%, p=0.62), procedure type (repeat ablation: 8.4% vs 13.4%, p=0.29), more extensive lesion set than PVI only (28.9% vs 22.5%, p=0.22) and the use of 3D mapping system (22.9% vs 21.1%, p=0.67). By looking at procedural metrics, no differences were also found between groups: 73±28 min vs 72±32 min for skin-to-skin time, p=0.41; 93±41 min vs 88±43 min for preparation plus skin-to-skin time, p=0.11; 18±9 min vs 17±9 min for fluoroscopy time, p=0.61 and 32[32-40] vs 32[32-38] PFA spots to achieve PVI, p=0.29. PVI was achieved in all patients. No major procedure-related adverse events were reported. Conclusion In our experience, the use of Farapulse PFA system for AF ablation in elderly patients was rapid, safe and effective, with no differences compared to the younger population.

Optimizing ablation sites in recurrent atrial fibrillation cases: a novel approach using emphasize settings

Abstract Backgrounds Although catheter ablation techniques for atrial fibrillation (AF) have advanced, a certain number of cases of re-conduction after pulmonary vein isolation (PVI) still exist and are the most common cause of recurrence of atrial tachyarrhythmias. In some cases, the diversity of anatomical wall thickness and fiber orientation around the PVs might contribute to re-conduction. Identification of optimal target ablation site of re-conduction could reduce unnecessary ablation and decrease the risk of complications. However, in cases where local electrograms consisted with far filed and near filed potentials were coexist, conventional activation mapping with bipolar electrograms sometimes fails to identify the re-conduction sites. Purpose We investigated the utility of using the Emphasize settings in the emphasis map obtained by combining activation mapping and peak frequency mapping in the EnSite X system to determine the optimal ablation sites compared to the conventional map based on the activation mapping. Methods Patients undergoing AF ablation of PVI with the EnSite X system who had recurrent cases or had PVI re-conduction at the initial ablation were included. We retrospectively analyzed the cases from January 2022 to November 2023. In all cases, bipolar voltage and activation maps for left atrium and PVs were obtained by a 16-pole grid catheter (Advisor HD Grid) during atrial pacing or sinus rhythm. Local activation timing and peak frequency maps of the left atrium were performed to obtain the Emphasize settings indicating the optimal ablation sites (E-group). The Emphasize settings obtained from the maps were adjusted to make the site of re-conduction most apparent (Figures). Another group determined the ablation sites based on the activation mapping (A-group). The clinical backgrounds, laboratory data, and echocardiography data were also evaluated. Intravenous administration of ATP was performed in all targeted PVs after successful re-isolation of PVs. Results Total 44 patients (69±10 years, 32 males) and 90 PVs were found to be re-conducted and analyzed. The gaps of 34 and 40 points of PVI were observed in the E-group and C-group, respectively. The number of needs for the ablation points to successful elimination of gap was markedly smaller in the E-group (1.3±0.7 vs. 6.2±3.2, p&amp;lt;0.001). The optimal Emphasize settings was 340 ±75 Hz in the E-group. None of the cases showed dormant conductions by ATP administration in both groups. There were no differences in age, gender, left atrial volume index, left ventricular ejection fraction, serum creatinine levels, and N-terminal pro-brain natriuretic peptide levels between the two groups. Conclusion The optimal ablation site was visualized by adjusting the Emphasize settings, and the number of ablation points to re-isolation of PV might be markedly reduced.

Atrial fibrillation ablation performed under general anesthesia is associated with significantly low arterial blood pressure and higher incidence of hypotensive events

Abstract Introduction Catheter ablation is a pivotal treatment for atrial fibrillation (AF). When performed under general anesthesia (GA), it may be associated to hypotensive events, with unclear prevalence and prognostic impact. Continuous non-invasive blood pressure (CNBP) measurement is a validated and reliable tool for intraprocedural beat-to-beat advanced hemodynamic monitoring. Purpose To assess and compare the hemodynamic impact of GA during AF ablation using a CNBP (ClearSight) system. Methods In an observational single large volume center study we prospectively enrolled all patients undergoing AF ablation at our institution with CNBP monitoring, as per local practice. Patients were assigned to deep sedation (DS) or general anesthesia (GA) group according to the chosen sedation regimen. The following parameters were compared between the two strategies: systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke volume index (SVI). Hypotension events (HE) (MAP &amp;lt; 65 mmHg) were counted and compared between groups. Results Two hundred patients were enrolled from September 2022 to August 2023. 170 patients underwent AF ablation under DS (76,7% male, mean age 56,77±15,76), while 30 patients were treated under GA (70% male, mean age 60,72±13,79). A total of 117709 measurements were analyzed and compared, for an overall monitoring time of 39293,66 minutes. Patients treated under GA had significantly lower average SBP (104,83±21,48 mmHg vs 138,05±22,09 mmHg, p&amp;lt;0,001), DBP (59,59±11,89 mmHg vs 76,12±12,75 mmHg, p&amp;lt;0,001), MAP (74,96±15,02 mmHg vs 97,12±15,38 mmHg, p&amp;lt;0,001). We also observed significantly lower CO (4,40±1,47 L/min vs 5,16±1,62 L/min, p&amp;lt;0,001), CI (2,22±0,71 L/min/m2 vs 2,61±0,78 L/min/m2, p&amp;lt;0,001) SV (62,37±18,04 mL/beat vs 70,65±24,95 mL/beat, p&amp;lt;0,001) and SVI (31,40±8,54 mL/beat/m2 vs 35,80±12,07 mL/beat/m2, p&amp;lt;0,001). Patients treated under GA witnessed a higher number of per-patient HE (10,53±9,16 vs 0,61±2,07, p&amp;lt;0,001), and higher HE duration (4,8±6,62 min vs 2,82±3,66, p&amp;lt;0,001). Conclusion AF ablation performed under general anesthesia is associated with significantly lower systolic, diastolic, and mean arterial pressure, reduced cardiac output, stroke volume and stroke volume index when compared to deep sedation. Patients undergoing AF ablation under GA witness higher incidence and duration of hypotensive events. CNBP is a valid tool for beat-to-beat procedural hemodynamic assessment and can help identifying and treat hypotensive events. Further studies are needed to assess the potential prognostic impact of intraprocedural hypotension during AF ablation.

Heterogenous atrial conduction in patients with hypertrophic cardiomyopathy and atrial fibrillation

Abstract Background/Introduction Hypertrophic cardiomyopathy (HCM) is characterised by myocardial thickening, fibrosis, and disarray, affecting both ventricles and atria. This pathology extends to atrial tissue, potentially influencing conductivity and contributing to arrhythmias, notably atrial fibrillation (AF). Pulmonary vein isolation to treat AF in HCM patients yields less satisfactory results compared to other patient groups. Improved understanding of the pathophysiology of AF in HCM patients could improve treatment stratification and delivery. Purpose This study aims to analyse atrial conduction properties in HCM patients with AF, compared to age, body mass index and sex-matched control patients. Methods Pre-ablation electroanatomic mapping data from 10 HCM patients and a matched control group of patients with structurally normal hearts undergoing AF ablation was retrospectively analysed. All patients underwent pre-ablation electroanatomic mapping during proximal coronary sinus pacing. This data was analysed using OpenEP software to quantify voltage mapping, conduction velocity and wave collision points. Conduction velocity was calculated using both plane fitting and triangulation methods. Wave collisions were identified by calculating the percentage of points with conduction velocity field divergence values less than -1.5. Results HCM patients exhibited significantly reduced mean left atrial bipolar voltage and greater low voltage burden &amp;lt;0.5mV than matched control patients (1.43mV vs. 2.14mV, p=0.0177; and 38.28% vs. 15.68%, p&amp;lt;0.0001), (Figure 1A and B). Wave collision points were significantly more prevalent in the HCM group (5.4% vs. 1.6%, p=0.0004), indicating more heterogeneous conduction (Figure 1C). Figure 2 shows example of divergence map with local electrograms around wave collision points. Both methods of quantifying conduction velocity showed comparable results. While average conduction velocity showed no statistically significant difference (plane fitting method - 0.61m/s in HCM group vs. 0.64m/s in control group, p = 0.465; triangulation method - 0.61m/s in HCM group, 0.64m/s in control group, p=0.393), a trend toward lower velocities in HCM patients was observed (Figure 1D and 1E). Conclusion HCM patients demonstrate significantly lower bipolar voltage and significantly greater low voltage areas than matched control patients. Atrial conduction in patients with HCM is significantly more heterogenous than matched control patients. These findings highlight marked conduction abnormalities in HCM patients which are likely to contribute to AF pathogenesis.

Real-world validation of smartphone-based photoplethysmography for heart rate monitoring in atrial fibrillation

Abstract Introduction Photoplethysmography (PPG) based smartphone applications facilitate heart rate monitoring that may enable physicians to guide rate control in patients with atrial fibrillation (AF). Despite extensive validation of PPG-derived heart rate, validation studies in the presence of AF are lacking, particularly in unsupervised free-living conditions. Purpose To evaluate the accuracy of PPG-derived heart rate using a smartphone application in patients with an established diagnosis of AF, both during sinus rhythm and AF, in a real-world setting. Methods Consecutive patients undergoing AF ablation were enrolled four weeks prior to the procedure. They were instructed to assess their heart rate twice daily during eight weeks with a one-minute finger-over-the-camera smartphone-PPG recording. The reference heart rate was obtained from two 30-seconds handheld single-lead electrocardiogram (ECG) recordings performed immediately before and after the PPG recording. Measurements were valid if the heart rate did not change by more than 10% between the first and second ECG and maintained sinus rhythm or AF consistently. Results In total, fifty patients (age 63 ±11 years, 68% male) performed 3407 high-quality PPG measurements accompanied with two high-quality ECGs measurements both in sinus rhythm or AF. After excluding 223 measurements due to inconsistent heart rate between the first and second ECG, 3184 measurements remained. The mean heart rate (71.5 ± 17.3 beats per minute (bpm)) was significantly higher during AF (94.7 ± 19.4 bpm) compared to sinus rhythm (65.7 ± 10.7 bpm) (p-value &amp;lt; 0.001). The heart rate assessment was accurate within a 10% margin in 93.8% of PPG measurements. Inaccurate heart rate assessments were more frequent in AF (161/637; 25.3%) compared to sinus rhythm (35/2547; 1.4%) (p-value &amp;lt; 0.001). PPG underestimated the heart rate in sinus rhythm with 0.4 bpm (95% CI: -0.3 to -0.5 bpm) and in AF with 6.6 bpm (95% CI: -5.8 to -7.4 bpm). The deviation of PPG-derived heart rate from the ECG-derived true heart rate was significantly greater during AF (root mean square error (RMSE) = 11.8 bpm) compared to sinus rhythm (RMSE = 2.2 bpm) (p-value &amp;lt; 0.001). The heart rate correlation plots and corresponding Bland-Altman plots demonstrate a skewed underestimation of the heart rate in AF with PPG, particularly for high heart rates. Conclusions Heart rate can accurately be derived from PPG recordings using a smartphone application in real-world conditions. However, PPG measurements may underestimate high heart rates in the presence of AF.Heart Rate in Sinus RhythmHeart Rate in Atrial Fibrillation

Predictors of low-voltage areas in the left atrium in patients with atrial fibrillation

Abstract Background Low-voltage areas (LVA) in the left atrium (LA) electroanatomical map are potent predictors of the efficacy of atrial fibrillation (AF) ablation. Clinical factors predicting the presence of LVA have moderate accuracy. The aim of the study was to find clinical and echocardiographic factors predicting the presence of LVA in patients undergoing AF ablation. Methods Consecutive unselected patients undergoing AF ablation were included in the retrospective analysis. All patients underwent transthoracic (including LA strains) and transesophageal echocardiography, pulmonary vein isolation and LA electroanatomical mapping using multipolar catheter. LVA were defined as an area greater than 2cm2 with a voltage below 0.5mV (or 0.3mV when measured during AF). Results A total of 432 patients were included in the analysis, 107 (24.8%) had LVA. The mean age of the study population was 62.8 years, 185 patients had nonparoxysmal AF (42.8%). In the univariate logistic regression analysis numerous clinical parameters (age, female sex, presence of heart failure, diabetes, coronary artery disease, AF during examination), echocardiographic parameters (LA reservoir strain - LASr, LA emptying fraction, LA volume index, E/e’, LA appendage velocity - LAAV) and mean LA pressure (measured invasively) were significant predictors of the presence of LVA. In the multivariate logistic regression analysis age (HR 1.11 per 1 year increase, p&amp;lt;0.001), LASr (HR 0.89 per 1% increase, p=0.014) and LAAV (HR 0.93 per 1cm/s increase, p&amp;lt;0.001) were significant predictors of the presence of LVA. In receiver-operator curve (ROC) analysis LASr and LAAV were potent predictors of LVA in patients tested on sinus rhythm (AUC 0.86 and 0.87 respectively), while they had moderate predictive value in patients tested on AF (LASr AUC 0.67, LAAV AUC 0.77). Conclusions Age, LASr, and LAAV were significant predictors of LVA in patients undergoing AF ablation. The predictive value of LASr and LAAV was better in patients examined during sinus rhythm than in patients examined during AF.

Impact of pulmonary vein variant anatomy during cryo-ablation in paroxysmal and persistent AF patients: 1-year outcome from a nationwide multicenter clinical setting

Abstract Background Complete electrical pulmonary vein isolation (PVI) by cryo-balloon approach is a well-established ablation strategy of atrial fibrillation (AF). While contrast findings exist regarding the influence of variant pulmonary vein (PV) anatomy on predicting AF recurrence, limited data are currently available specifically for cases involving the POLARx cryoablation system during PVI. Purpose We report the real-world experience of POLARx in the context of de novo AF ablation in a multicenter Italian registry. Methods Consecutive patients undergoing AF ablation from the CHARISMA registry at 10 Italian centres were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred &amp;gt;60 sec or when time to isolation was not available. The ablation endpoint was PVI as assessed by entrance and exit block. All patients were followed-up for at least 12 months after the procedure. Results Four-hundred twenty-nine patients were included (n=358, 83.4% paroxysmal AF, n=71, 16.6% persistent AF, mean age 60.7±10 years, 28.3% female, mean LVEF 58±8%). PVI was achieved in all pts using only cryoablation. Twenty-eight (6.6%) patients exhibited an anatomical variant: 17 (4.0%) a common ostium and 11 (2.6%) an adjunctive PV. The mean number of freeze applications per patient was 5.1 (1.2 for LSPV, 1.3 for LIPV, 1.2 for RSPV and 1.3 for RIPV). Over a median of 398[370-461] days of follow-up, 14 (3.2%) patients experienced an early recurrence of AF during the 90-day blanking period. Overall, 63 patients (14.7%) suffered an AF recurrence after the 90-day blanking period (median time to recurrence 342[171-381] days). The proportion of patients exhibiting AF/AT recurrences was higher in the persistent AF group (17 out 71, 23.9%) than in the paroxysmal AF group (46 out 358, 12.8%, p=0.026), with a hazard ratio of 2.02 (95%CI: 1.2 to 3.5, p=0.0137) whereas patients with anatomy variant showed a similar AF/AT recurrence rate (5 out 28, 17.9%) than in the standard anatomy group (58 out of 401, 14.5%) with a hazard ratio of 1.43 (0.6 to 3.6, p=0.441). Four (0.9%) transient phrenic nerve palsy were observed, both with full recovery in the 48-h post procedure; no major procedure-related adverse events were reported. Conclusion In this multicenter study, the cryo-balloon system demonstrated safety and efficacy in treating both paroxysmal and persistent AF patients, yielding a low incidence of AF/AT recurrence during follow-up, regardless of the presence of variant PV anatomy.