bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of the success of electrical cardioversion in patients with atrial fibrillation using parameters obtained by spectral and vectorcardiographic analysis of the ECG
Authors: Hassouna S , Herman D , Hozman M , Osmancik P , Vesela J , Plesinger F , Bures Z
Published: May 2024

Introduction

Electrical cardioversion (ECV) still presents a treatment option for atrial fibrillation (AF). Despite the great success rate in the acute setting, its long-term success rate is low. The aim of the study was to find predictors of SR maintenance after ECV using spectral and vectorcardiographic (VCG) analysis of the ECG curve.

Methods

Consecutive patients with AF referred for elective ECV were prospectively enrolled. The digital ECG recording obtained before the ECV was analyzed using spectral and VCG analysis. All patients had Holter monitoring and clinical follow-up three months after cardioversion to assess SR maintenance. Atrial fibrillation activity was analyzed by spectral analysis, determining the dominant frequency (DF), RI (regularity index) and OI (organization index). QRS complexes were analyzed by vectorcardiography and dXmean, dYmean and dZmean (derivation of VCG signals) parameters were determined. Using logistic regression (LR) with backward parameter reduction, separate and combined predictive models of SR maintenance were calculated based on both the analysis from the VCG data and the spectral analysis data. Additional models with a forward selection of clinical variables were also calculated. The efficiency of the models was evaluated on a separate test subset of the data (N=32).

Results

A total of 80 patients were enrolled (age 70+10 years, 48 (64%) men, CHADSVASc 3.17+1.5, BMI 29.75kg/m2). At the 3-month follow-up, AF recurrence was present in 36 patients (45%). Using only vectorcardiographic parameters, dXmean (OR 3.07, 95 %CI 1.14- 8.63), p=0.001) and dYmean (OR 0.26, 95% CI 0.09-0.72), p <0.001) best predicted the SR maintenance (AUC of 0.72).

Using only spectral analysis parameters, the best predictor was DF (OR 3.07, 95%CI 1.14-8.63), p=0.012) with AUC of 0.66. By combining the results of spectral analysis and vectorcardiography, an AUC of 0.78 was achieved. Among the clinical parameters, the most significant predictors were insufficiently controlled arterial hypertension and previous history of stroke.

Conclusion

Digital analysis of ECG curves using deeper mathematical models provides a better predictive model than classical clinical and echocardiographic models. The combination of spectral analysis of fibrillation atrial activity and vectorocardiographic analysis of QRS complexes revealed more accurate predictive information compared to both analyses alone.
Extended period rhythm outcomes of posterior box isolation of left atrium during pan-spectrum of atrial fibrillation catheter ablation in 4 randomized clinical trials
Authors: Lee S , Yu H T , Choi S H , Kim D H , Kim T H , Uhm J S , Joung B Y , Lee M H , Pak H N
Published: May 2024

Background

Catheter-based electrical posterior box isolation (POBI) in addition to circumferential pulmonary vein isolation (CPVI) did not improve rhythm outcome of atrial fibrillation (AF) catheter ablations (AFCA). We analyzed the long-term rhythm outcomes of previously conducted our 4 randomized controlled trials (RCTs) comparing CPVI vs. additional POBI by intention to treat.

Methods

We analyzed 575 AF patients who were included in 4 RCTs (PAF [paroxysmal AF], PEACEFUL [persistent to paroxysmal AF]; POBI [persistent and long-standing persistent AF]; and RILI [repeat procedures] trials) comparing the usefulness of additional POBI after further long-term protocol-based rhythm follow-up. We compared the primary endpoint as clinical recurrence after index procedure and major adverse cardiac event, and the secondary endpoint as procedure time, procedure-related complication rate, recurrence as atrial tachycardia (AT), and cardioversion or repeat procedure rates. We also conducted Cox regression analysis to evaluate the efficacy of POBI.

Results

After a median follow-up of 48months, there was no significant difference in the clinical recurrence (42.9% vs. 41.3%; log-rank P=0.855) and major adverse cardiac event (4.5% vs. 3.7%; log-rank P=0.675). Procedure time was significantly longer (p=0.003) and AT recurrence rate was higher (6.6% vs. 12.6%; log-rank P=0.014) in the additional POBI group. In patients who experienced clinical recurrence, there were no significant differences in the rates of cardioversion (33.9% vs. 46.6%, P=0.059) or the need for a repeat procedure (30.4% vs. 31.7%, P=0.955) between the two groups. Catheter-based POBI did not improve AFCA outcomes (HR 1.07 [0.81~1.40], P=0.655), regardless of paroxysmal, persistent to paroxysmal, persistent AFs, or the 2nd procedures. In the redo mapping after RCTs (n=64), PV reconnection rate did not differ, but reentrant AT was more common in POBI than in CPVI alone group (46.7% vs. 10.7%, P=0.007), while extra-PV trigger was more common in CPVI alone than in POBI group (29% vs. 3.0%, P=0.012).

Conclusions

Additional-POBI to CPVI did not improve long-term rhythm outcomes. Additional-POBI to CPVI is related to the increase of AT recurrence and the decrease of extra-PV trigger.
Validation of the Castle HTx data in a real world scenario
Authors: Scheurlen C , Van Den Bruck J H , Filipovic K , Erlhoefer S , Woermann J , Dittrich S , Schipper J H , Pavel F , Ackmann J , Lueker J , Steven D , Sultan A
Published: May 2024

Background

Pulmonary vein isolation (PVI) is recommended in patients with symptomatic atrial fibrillation (AF) and reduced left ventricular ejection fraction (LVEF). Recently the Castle HTx (CHTx) trial showed a significant mortality reduction in end stage heart failure patients undergoing PVI in addition to optimized medical therapy (OMT) compared to OMT only.

Aim

Objective of this analysis is to validate results of Castle HTx study in a real world scenario.

Methods

All patients between September 2021 und September 2023 referred for PVI at our center with symptomatic AF und LVEF ≤35% were included in this retrospective analysis at the University Hospital Cologne.

Results

A total of 119 PVI in patients with LVEF≤35% were successfully performed (mean age 63.3±10.1 years, 96 patients (81%) male, 43 (36%) paroxysmal AF, 76 (64%) persistent AF) matching inclusion criteria used in CHTx. Cryo-PVI was used in 50 (42%), RF-PVI in 60 (50%) and PFA in 9 (8%) patients. Complete follow-up (FU) with a mean of 549.6±430.2 days was obtained in 108 patients, comparable to CHtx (540 days). During FU 11 patients (10%) died from any cause (CHTx 8 patients (8%)), 2 patients (2%) received a left ventricular assist device (CHTx 1 patient (1%)) and no patient had urgent heart transplantation (CHTx 1 patient (1%)). For 30 patients (28%) recurrence of AF was detected and 72% remained in sinus rhythm.

In 6 patients (5%) post-procedural complications occurred: 5 inguinal hematoma, 1 decompensation.

During FU LVEF was statistically significantly improved (EF initial 26.9±6.5%, EF FU (n=80) 37.1±12.8%, p<0.001) (CHTx EF initial 29.0±6.4%, EF FU (n=92) 37.2±9.1%).

Conclusion

The findings of the Castle HTx patients have been validated in a real-world setting. PVI for rhythm control in end stage heart failure patients is safe and highly effective. Our patient cohort, matched to the Castle HTx ablation group, showed freedom from AF rate of 72% after mean FU time of 550 days. Furthermore, LVEF was improved significantly in our cohort echoing the results from CHTx.
Pulmonary vein isolation using pulsed field ablation versus high-power-short-duration radiofrequency ablation for paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up
Authors: Reinsch N , Hartl S , Fueting A , Neven K
Published: May 2024

Background

Pulsed field ablation (PFA) is a novel, nonthermal, cardiac tissue selective ablation modality. To date, radio-frequency (RF) guided high-power-short-duration (HPSD) ablation represents the gold standard for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). This study investigated the efficacy of PFA-PVI versus HPSD-PVI in terms of single-procedure arrhythmia-free outcome and safety.

Methods

Consecutive, paroxysmal AF patients who underwent PVI using PFA or HPSD were enrolled. In group PFA, PVI was performed using a 31/35-mm pentaspline PFA catheter. The ablation procedure in group HPSD was performed with HPSD-RF energy (45 watts), using Ablation Index (AI) and the CLOSE protocol. The CLOSE protocol combines AI and ≤6 mm interlesion distance using a 4-mm surround flow catheter.

Results

A total of 420 patients (group PFA: 211; group HPSD: 209) were included (55% men; age 67 ± 10 years). There was no difference between both groups with regard to age, gender and CHA2DS2-VASc-Score. Complete isolation of all PVs was achieved in 100% of patients. Procedure time was significantly shorter in group PFA (74 ± 41 min vs. 127 ± 34 min; p < 0.001); fluoroscopy time and dose area product were significantly longer in group PFA (18 ± 7 min vs. 4 ± 3 min; p < 0.01 and 555 ± 460 uGym2 vs. 213 ± 273 uGym2; p <0.01). Overall procedural complications were 1,4% in group PFA and 5,2 % in group HPSD (p < 0.01), driven by a higher tamponade rate in group HPSD. During a mean follow-up of 12 months after a single procedure, 170 (81%) patients of group PFA were free of arrhythmia recurrence versus 160 (76%) patients in group HPSD (p = 0.798) (Figure 1).

Conclusions

PVI using PFA compared to PVI using HPSD shows a similar acute efficacy but a significantly reduced complication rate and a shorter procedure time. One-year clinical success rates are favorable, but not different between groups.Figure 1
Cryoballoon ablation for atrial fibrillation in young adults: a propensity-score matching comparison with an older cohort
Authors: Cecchini F , Mugnai G , Di Vilio A , Almorad A , Del Monte A , Artale P , Filannino P , Petretta A , Colella J , Statuto G , Maj R , Sieira J , Chierchia G B , De Asmundis C , Iacopino S
Published: May 2024

Background

Cryoballoon ablation (CB-A) has proven to be a valid technology for achieving pulmonary vein isolation (PVI) in patients affected by symptomatic atrial fibrillation (AF). Data regarding CB-A in young adults are still scarce and mainly derived from studies performed without balancing comorbidities and echocardiographic parameters between the groups. The present study aimed to focus on the outcomes and complications of CB-A PVI in young adults (< 50 years) compared to a propensity score-matched population of older individuals, seeking also to understand the true role of "age" as potential risk factor for arrhythmia recurrences.

Methods and results

We retrospectively enrolled 172 consecutive patients aged < 50 years who underwent PVI employing the second-generation cryoballoon (CB-2). A 1:1 propensity score matching comparison with an older cohort of patients was performed and 290 patients (145 subjects aged < 50 years vs. 145 patients aged ≥ 50 years) were then selected. The mean age was 43.3 ± 4.9 years in the younger group and 64.7 ± 8.7 years in the control group (p < 0.001). After an overall median follow-up of 18 [12 - 29] months, the Kaplan-Meier curves showed a similar rate of freedom from arrhythmia relapses between the younger and the older cohorts (85.5% vs. 77.2% respectively, log-rank p = 0.31). The rate of major complications was low (2.8 %) and did not significantly differ between the groups, being 2.1% for the younger cohort and 3.5% for the older group (p = 0.50). Vascular complications and phrenic nerve palsy appeared to be the most common procedure-related adverse events, occurring in 8 (2.8%) patients. Arrhythmia recurrences during blanking period (ERAF) was found to be the only independent predictor of late AT/AF relapses.

Conclusions

Our propensity-score model demonstrates that CB-A PVI is equally safe and effective in young adults as it is in older individuals. Furthermore, our findings suggest that "age" itself does not appear to play a significant role in predicting recurrences after CB-A PVI. This result underscores the importance of controlling the modifiable risk factors (comorbidities) and emphasizes the value of early AF diagnosis and intervention.Survival Curve
Optimizing pressure-guided cryoablation of pulmonary veins
Authors: Madero S , Herreros Guilarte B , Diez De Las Heras D , Munoz San Jose J C
Published: May 2024

Background

Pressure-guided cryoablation (PGC) is a contrast-free technique used to isolate Pulmonary Veins (PV) in order to treat atrial fibrillation (AF). In this technique the main goal is to achieve a wedge curve to assure adequate vein occlusion(1). As the wedge curve is not always clear, we hypothesize that the wedge pressures (systolic, diastolic and mean) could be useful as reliable surrogate markers.

Purpose

The aim of this study is to evaluate wedge pressures in individual vein occlusions in a cohort of patients referred for PV isolation using PGC.

Methods

Between February 2022 and October 2023, 23 patients (7 female, 13 paroxysmal AF) underwent PV isolation using PGC protocol. No REDOs were included. The procedure was intended to obtain PV isolation with one shot of 240 seconds. All patients underwent computed tomography angiography or MRI of LA and PV. A 28-mm Cryoballoon and a Intracardiac echo were used in all the procedures. Invasive radial arterial and LA pressures were registered. We analysed all the shots per vein and compared data between successful and unsuccessful isolation. Multivariate statistical analysis was performed, being the PV isolation the main outcome.

Results

There were realized 125 applications in 92 veins, being isolated 100% of them. One vein (left superior) was isolated after application in inferior ipsilateral vein, so it was considered successful as there was no need of additional applications. Eleven applications were performed as a bonus, so they were not considered for the isolated-non isolated analysis. Wedge curve was obtained in 112/119 applications (the 7 applications with not adequate wedge curve were 3 in right superior and 4 in right inferior pulmonary veins). In 5 applications the graphic curve was not reliable, but the pressure values were registered. There were significative differences in nadir temperature, systolic, diastolic and mean vein pressures, and the presence of a wedge curve. In the multivariate analysis, the nadir temperature (OR 0.79 CI95% 0.70–0.90) and the diastolic vein pressure at occlusion (OR 1.16 CI95% 1.01–1.36) were the only independent predictor factors of PV isolation.

Conclusion

With these results, we conclude that the monitoring of diastolic PV pressure during applications and the nadir temperature are the best markers to predict a successful isolation in the PGC.Figure 1.Pressure waveformTable 1.Application characteristics
Preprocedural atrial fibrillation burden is associated with recurrence in patients undergoing atrial fibrillation ablation: findings from the ISOLATION AF Ablation Cohort Study
Authors: Habibi Z , Verhaert D V M , Hermans B J M , Philippens S A M , Westra S W , Chaldoupi S M , Maesen B A E , Isaacs A J , Zeemering S , Linz D , Vernooy K , Schotten U
Published: May 2024

Background

Non-invasive quantification of electrophysiological properties of the atria is increasingly used for outcome prediction in atrial fibrillation (AF) patients. Data on the benefit of the current classification of AF compared to AF burden based on single lead ECG measurements to predict AF recurrences are scarce.

Objective

This study sought to assess the predictive performance of low versus high AF burden compared to the conventional AF classification for predicting recurrences after AF catheter ablation.

Methods

A cross-sectional analysis was conducted in AF patients scheduled for catheter ablation included in the prospective multicenter ISOLATION cohort study between July 2020 and November 2022. Clinical characteristics, routine tests, blood tests and rhythm monitoring through single lead ECGs were collected prior to ablation. ECGs were recorded three times daily for four weeks, with additional measurements in case of the onset or relief of symptoms. The primary endpoint was "ablation success" defined as freedom from documented arrhythmia after the blanking period. Of 650 included patients, pre-procedural rhythm monitoring was available in 580. 261 patients had at least 14 days of ECG measurements and completed 12 months of follow-up. In these patients, we compared the recurrences after 12 months between paroxysmal and persistent AF and high versus low AF burden through survival analysis. Maximally selected rank statistics were used to determine the best cut-off value for AF burden.

Results

In 261 patients, the mean age was 64 ± 9 years, and 33.7% were female. Physicians classified 170 patients (65.1%) as paroxysmal AF and 91 (34.9%) as persistent AF based on medical history. The AF burden is shown in Figure 1. The optimal calculated cut-off value for AF burden was 42%. Out of 170 patients with paroxysmal AF, 17 (10%) had a burden of > 42%. Of the 91 patients with persistent AF, 35 (38%) had a burden of < 42%. After 12 months, a significant difference in recurrences was observed between patients with paroxysmal AF versus persistent AF (p= 0.015). Patients with high AF burden, had more recurrences after 12 months, than patients with a low AF burden (p= 0.006) (Figure 2).

Conclusion

Our preliminary results suggest that the addition of a new classification of AF based on burden might provide additional benefit in predicting AF recurrences after catheter ablation compared to the current existing classification and may improve prognostication. Completion of patient follow-up is necessary to determine the predictive value of AF burden derived from single lead ECGs for the prediction of AF recurrence.Figure 2.
Atrial fibrillation cryoablation guided by pressure waveform: a prospective multicentre registry
Authors: Fontenla Cerezuela A , Cozar R , Sanchez-Millan P J , Fernandez-Palacios G , Gonzalez-Casal D , Gaztanaga-Aranzamendi L , Jimenez-Lopez J I , Ballesteros G , Gonzalez-Panizo J , Garcia-Salvador J J , Izquierdo-Bajo A , Alvarez M , Garcia-Fernandez F J , Cabrera J A , Datino T
Published: May 2024

Background

Cryoballoon ablation (CA) procedures require optimal occlusion of the pulmonary veins (PV), which is conventionally evaluated by iodine contrast injection through the catheter tip. This technique has some weaknesses such as risk of allergic reactions, nephrotoxicity, requirement of fluoroscopy (sometimes at high doses), requirement of a second operator, among others. PV pressure waveform assessment is an alternative method for confirming occlusion, however, multicentre assessment of periprocedural efficacy and safety is lacking.

Purpose

To describe the intra-procedural performance and safety of routine pressure-based CA.

Methods

In this independent prospective multicentre observational study, baseline and procedure data from consecutive pressure-guided CB ablations were collected. Operators were not required to have experience in pressure-guided CA for participating in the registry. They were asked to classify the pressure waveform curves into type 1 (presence of "a-wave" and/or symmetric "v-wave", meaning incomplete PV occlusion) and type 2 (absence of "a-wave" and asymmetric "v-wave", meaning complete PV occlusion), Figure 1. The primary endpoint was PV isolation in all veins without use of contrast. Procedure performance and adverse events were also analyzed.

Results

A total of 150 patients (mean age: 61 ± 10 y.) with paroxysmal (62%) or persistent AF (38%) were included and underwent pressure-guided CA in 9 centres from Spain. Complete PV isolation was achieved in 148 patients (98%). The operators switched to contrast use in 14 cases (9%), mainly to double check the occlusion. Total procedure and fluoroscopy time were 97 ± 39 and 19 ± 10 min respectively. There were 7 (4.7%) procedure related adverse events: 4 phrenic nerve palsy (3 of them were transient), 1 transient coronary ST elevation (before ablation), 1 gastroparesis and 1 femoral pseudoaneurysm. Most relevant results are summarized in Figure 2.

Conclusion

In this multicentre and multi-brand assessment, CA guided by pressure waveforms provided outstanding procedural outcomes, which were equivalent to those reported with the conventional approach. All operators could easily obtain and identify the waveform without a specific learning curve, avoiding the use of iodine contrast in most cases. The long-term efficacy of this approach will be presented in future analyses.Pressure waveforms types in cryoablationProcedural data
Biochemical markers of neuro-myocardial damage after pulmonary vein isolation: the effect of different energy sources
Authors: Stojadinovic P , Alfredova H , Filova V , Wichterle D , Peichl P , Cihak R , Borisincova E , Stiavnicky P , Haskova J , Franekova J , Kautzner J
Published: May 2024

Background

Pulmonary vein isolation (PVI) by thermal energy, both radiofrequency (RF) and cryoenergy(Cryo), is associated with a significant release of myocardial and collateral neural injury markers. Damage to periatrial ganglionated plexi also results in a substantial change in cardiac autonomic regulations. On the contrary, pulsed electric field (PEF) energy tends to spare cardiac neural tissue.

Purpose

To quantify the impact of different ablation energy sources that are used for PVI on neuro-myocardial damage by the assessment of specific biomarkers.

Methods

A study enrolled 85 patients with paroxysmal atrial fibrillation who underwent PVI (age: 61 ± 12 years, 74% males). In 23 patients, RF energy was delivered by the irrigated-tip catheter, while 30 patients were ablated using a second-generation cryoballoon catheter. In 32 patients, PVI was performed using a multipolar pentaspline catheter and PEF energy. Peripheral venous blood samples for assessing the plasmatic levels of S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), high-sensitivity troponin I and T (hsTnI and hsTnT) were obtained before, immediately after the PVI, and the next day (usually 18-24 hours after the procedure). Study groups were compared regarding absolute biomarker levels and hsTnT/S100B ratio (a surrogate of cardioselectivity).

Results

Following successful PVI, a significant increase in plasma levels of all biomarkers was observed: DhsTnT = 1040±434 ng/L, 1731±830 ng/L and 1010±397 ng/L; DhsTnI = 1504±918 ng/L, 16464±11911 ng/L and 10789±7589 ng/L; DS100B: 0.04±0.02 mg/L, 0.03±0.04 mg/L and 0.14±0.08 mg/L; DNSE: 34±72 ng/mL, 27±53 ng/mL and 45±52 ng/mL (all with P <0.001) for RF, PEF and Cryo groups, respectively. A direct comparison of maximal biomarker levels between study groups is depicted in the Figure. The hsTnT/S100B ratio was 23±14, 12±6, and 6±3 in PEF, RF, and Cryo groups, respectively (ANOVA P <0.01), indicating that PEF was 1.9-times and 3.8-times more cardioselective than RF and Cryo, respectively. Following the PVI, the heart rate accelerated by 2±8, 13±14, and 9±11 bpm in the PEF, RF, and Cryo groups, respectively. No correlation was observed between S100B release and HR acceleration (R = 0.07, P = 0.55).

Conclusion

Compared to thermal energy sources, PEF energy induces more specific damage to cardiomyocytes than cardiac nerves. There was no correlation between S100B release and HR acceleration.
Injury to the sinus nodal artery during radiofrequency ablation of atrial fibrillation and atrial tachycardia: its prevalence and treatment with percutaneous coronary intervention
Authors: Sakamoto Y , Itoh M , Yamashiro K , Yoshimoto D , Naganawa H , Yamaguchi R , Sato K , Takeya M , Yamamoto M , Habara M , Terashima M , Suzuki T , Nakagawa H
Published: May 2024

Background/Introduction

Injury to the sinus node artery (SNA) leading to SN dysfunction during radiofrequency catheter ablation (RFCA) of atrial Fibrillation (AF) and atrial tachycardia (AT) has been reported.

Purpose

The purpose of this study was to elucidate the prevalence and clinical course of SNA injuries during RFCA of AF/AT and examine the efficacy of the percutaneous coronary intervention (PCI) to restore SN function.

Methods

We retrospectively analyzed data from 6,906 consecutive patients (pts) who underwent RFCA of AF/AT (6,379 pts with AF ablation and 527 pts with AT ablation) in two institutions between January 2013 and December 2022.

Results

Among 6,906 pts, 9 (0.13%) pts developed SN dysfunction due to SNA injury during RFCA (8 with AF, 1 with AT). Acute SNA injury (total occlusion or severe narrowing of the SNA) was confirmed by coronary angiography (CAG) during the RFCA session in 8/9 pts. In the remaining patient, SNA injury was suspected based on the CT angiography. The culprit sites of the SNA injury were located at the septal site of the superior vena cava-right atrium junction in 4 pts (44%), on the left atrial appendage ridge in 3 (33%), on the roof of the left atrium adjacent to the right superior pulmonary vein in 1 (11%), and in the persistent left superior vena cava in 1 (11%). PCI to the occluded SNA was performed in 8 of the 9 pts: 1) coronary blood flow of the SNA was restored by a 0.014" guidewire advancement into the occluded artery using a micro-catheter followed by direct nitroprusside injection in 4 pts; 2) the direct balloon angioplasty using 0.75-1.5 mm diameter balloons was required to maintain the blood flow of SNA in 3 pts; and 3) CAG revealed spontaneous recovery of the blood flow of SNA in one pt. The remaining patient did not receive the CAG/PCI. All 8 pts who underwent the PCI resulted in restoration of normal sinus rhythm. During a median of 44 months follow-up, all 8 pts who received the PCI maintained normal sinus rhythm, while one patient without PCI demonstrated persistent SN dysfunction.

Conclusions

SNA injury during RFCA is a rare but critical complication. Prompt recognition by CAG and subsequent PCI effectively restores SN function in pts with unexpected SN dysfunction during RFCA procedures.
Optimizing ablation sites in recurrent atrial fibrillation cases: a novel approach using emphasize settings
Authors: Okajima S , Fujimoto Y , Ito N , Arai T , Hachisuka M , Hagiwara K , Murata H , Aizawa Y , Yodogawa K , Shimizu W , Asai K , Iwasaki Y
Published: May 2024

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<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.
Correlation between Lesions Size Index (LSI) and impedance dynamics during radiofrequency ablation for atrial fibrillation: impact of lesion duration and contact force
Authors: Sanchez Somonte P , Martinez Cossiani M , Guido L , Merino Fuentes D , Sanz B , Martinez Maldonado M E , Handayani A , Carton A , Jauregui M E , Castrejon-Castrejon S , Merino J L
Published: May 2024

Introduction

Impedance drop has been employed as a surrogate marker for lesion formation with its magnitude correlated to lesion size in in-vitro studies. The Lesion Size Index (LSI), and algorithm from Abbott Medical, serves as a predictor for lesion formation during radiofrequency (RF) ablation. While this formula integrates contact force (CF), lesion duration and power, it currently leaks impedance information. The new module of Ensite Cardiac Mapping system (Abbot) is capable of measuring the "filtered" impedance during each RF lesion, effectively eliminating artifacts from cardiac and respiratory oscillations. The objective of this study is to examine the correlation between the LSI and the average impedance drop during RF lesion formation.

Methods

We included a total of 18 consecutive patients who underwent catheter ablation for atrial fibrillation (AF) with Ensite Mapping System (Abbot). In all cases, 40 watts (W) were applied and the target LSI was set as 5 for the posterior wall and 6 for the anterior wall. For each lesion, the software automatically annotated the initial impedance, final impedance, average impedance drop (filtered), lesion duration and average contact forced (CF). The correlation between LSI, impedance drop and CF was assessed.

Results

A total of 1300 RF lesions delivered during AF ablation were analyzed. Mean LSI was 5.3 ± 0.8, mean average impedance drop was 10.9± 5 ohms and mean CF 12.3±6 grams (g). The LSI showed a weak but statistically significant correlation with the impedance drop (Person correlation=0.3; p<0.001). When ablation lesions were grouped by duration (<20 seconds, 21-40, 41-60, >60 seconds), the correlation between LSI and impedance drop remained weak but statistically significant for lesions shorter than 20 seconds (p<0.001) and lesions between 21 and 40 seconds (p<0.001). However, there was no longer correlation for lesions between 40-60 seconds and those longer than 60 seconds (Figure1). Mean CF for each group (from <20 to >60 seconds) was 15 ±7 g vs 11 ±5 g vs 9 ± 3 g vs 7± 3g respectively (p<0.001) (Figure 2), suggesting that the CF is key to improve the predictive value of LSI.

Conclusions

The LSI shows a weak correlation with the average impedance drop during AF ablation. This correlation is influenced by lesion duration, which is ultimately dependent on CF. These findings emphasize the ongoing need to optimize predictive models for RF lesion formation in the ever-evolving landscape of AF treatment.Figure 1Table 1
High-density mapping-guided ventricular tachycardia ablation in patients with ischemic cardiomyopathy: outcomes from a tertiary center cohort in Switzerland
Authors: Guan F U , Brunckhorst C , Wolber T , Breitenstein A , Molotor N , Gonca S , Duru F , Saguner A M
Published: May 2024

Background

Substrate-based ablation has emerged as a successful technique for VT ablation, especially in patients with ischemic cardiomyopathy with markedly reduced left ventricular function. High-density mapping catheters provide high-resolution electroanatomical maps and better discrimination of abnormal substrates and local activation in the heart chambers, making them a valuable and safe resource in the electrophysiology laboratory.

Purpose

The purpose of this study was to investigate differences in procedural characteristics and clinical outcomes of VT ablation with ischemic cardiomyopathy. VT ablations were guided by two mapping strategies: high-density mapping using a high-density mapping catheter and conventional mapping using an ablation catheter.

Methods

Patients with ischemic cardiomyopathy receiving VT ablation at our center between January 2018 and June 2023 were retrospectively included. Procedural characteristics and clinical outcomes were compared between patients receiving high-density mapping with a multielectrode-mapping catheter vs conventional mapping with a single-tip irrigated ablation catheter.

Results

Eighty-four patients with ischemic cardiomyopathy who underwent VT ablation were consecutively included (mean age 67 ± 12 years, mean LVEF 32 ± 11 %, 79 (94%) males). Fifty-seven (68 %) procedures were performed using high-density mapping, and 27 (32 %) conventional mapping. In the high-density mapping and conventional mapping group, the total procedure time was 256 ± 77 min vs. 232 ± 61 min (P < 0.05) and the total fluoroscopic dose was 1643 ± 204 μGy.m2 vs. 948 ± 105 μGy.m2 (P < 0.05), respectively,. However, there was no difference between the two groups in terms of acute success (84% vs 80%, P > 0.05) or major complications (5% vs 4%, P > 0.05). The mean duration of follow-up was 2.6 years (4 - 51 months). The 1-year mortality rates were 4% vs 7% in the high-density mapping and conventional mapping groups, respectively (P < 0.05). The 3-month and 1-year single-procedural sustained VT/VF-free rates were 77% vs 59% and 74% vs 63%, respectively (P < 0.05). The 1-year incidence of sustained VT/VF recurrence was 7.0 per 100 person-years in high-density mapping group, compared with 7.4 per 100 person-years in the conventional group.

Conclusions

VT ablation in patients with ischemic cardiomyopathy using high-density mapping appears to be superior to conventional mapping in terms of reducing postprocedural VT/VF recurrence and a subsequent reduction of overall mortality.Figure 1Figure 2
Electrophysiological findings, incidence, and predictors for AF recurrence after pulsed field versus radiofrequency pulmonary vein isolation. A retrospective analysis
Authors: Eberl A , Manninger M , Rohrer U , Reischl A , Zirlik A , Scherr D
Published: May 2024

Background

Pulsed field ablation (PFA) is an emerging method for catheter ablation of atrial fibrillation (AF). Data comparing efficacy and safety of PFA compared to thermal ablation is still scarce. In this study, we compared a cohort of patients who underwent PFA with those who received very high power short duration (vHPSD) radiofrequency catheter ablation at the University Hospital Graz.

Methods

We analysed baseline data from both cohorts (PFA: n=231; RF: n=243). Both procedures were performed under deep sedation, using propofol and fentanyl. The PFA procedure involved 2x2x2 pulses, with additional pulses as required. RF procedures were performed using the QDOT Micro catheter to deliver 90 watts of energy over 4 seconds.

Statistical analysis was performed using IBM SPSS Statistics for Windows, version 29. The Kruskal-Wallis test was used for quantitative non-parametric data in the baseline analysis, and the Man-Whitney-U test was used for quantitative non-parametric procedural data. For qualitative variables the Chi-squared test was used. A p-value of less than 0,05 was considered significant.

Results

Both groups were similar, apart from chronic heart failure, which was more prevalent in the RF group (p=0.003). Mean age for both groups was 62±10 years and mean body mass index did not differ as well. CHADS-VASc score was 2±2 in the RF and 2±1 in the PFA group (p=0.7). The types of AF were distributed as follows: (RF vs.PFA): PAF: 64%/61%; persAF: 34/36%; long standing persAF: 2%/3%.

As to this date performing a CTI line with PFA is off-label, a significantly higher number of patients with additional flutter were ablated in the RF group. In the RF-group, 91 patients underwent additional cavotricuspid isthmus ablation, compared to only 14 patients in the PFA group (p<0.001). Procedural time (RF:PFA 122±min:57±26min; p<0.001), fluoroscopy time (RF:PFA 15±9min:19±9min; p<0.001) and fluoroscopy dose (RF:PFA 17±40Gycm2:15±15Gycm2, p=0.026) showed significant differences, with procedural time and fluoroscopy dose presenting lower values in the PFA group. First pass isolation was achieved more frequently in the PFA group (85% vs. 57%; p<0,001). There was significant difference in recurrence rates between the vHPSD and PFA groups (RF: 56/242 (28%), PFA: 38/231 (17%); p=0.005). Additionally, time to recurrence in the RF group was 138±117 days, compared to 166±84min in the PFA group. We exclude operator dependence as the same operators performed both procedures.

Conclusion

Based on our findings, PFA could potentially become the standard procedure for many patients. However, randomized trials are needed to confirm these findings.
Superior vena cava isolation in paroxysmal atrial fibrillation - mind the phrenic
Authors: Pasara V , Prepolec I , Ban B , Pezo-Nikolic B , Puljevic D , Milicic D , Velagic V
Published: May 2024

Background

Pulmonary vein isolation (PVI) is the standard of care for patients with atrial fibrillation (AF), but medium-term success rates are far from ideal. Therefore, new methods are being developed, with emphasis on ectopic foci outside the pulmonary veins. Superior vena cava (SVC) is one of the most important non-pulmonary origins of AF and some studies suggested that empiric SVC isolation could improve outcomes in ablation of paroxysmal atrial fibrillation (PAF). Although complications have been reported in SVC ablation, most studies found complication rates of SVC ablation similar to conventional cryoballoon PVI.

Aim

This prospective, single-center study aimed to assess the complication rate and success rate of PVI followed by SVC isolation by cryoballoon application in comparison with conventional cryoballoon PVI.

Methods

We designed an unblinded, randomized clinical trial and recruited consecutive patients with PAF who were randomized to a conventional cryoballoon PVI or PVI and additional SVC cryoballoon isolation using single 180 s freeze.

Results

A total of 140 patients (61.4% male, mean age 62.1 years) with PAF were included and 67 (47.9%) were randomized to SVC isolation in addition to conventional ablation. Planned 180-s freeze in the SVC could be completed in 15 (22.4%) patients, while 27 (40.3%) patients received at least 120-s freeze. The mean time to SVC isolation was 40.2 ± 37.9 s. Real-time recording of SVC isolation was observed in 39 (58.2%) patients. Right phrenic nerve palsy (PNP), impending or transient, occurred in 6 (8.2%) patients in the PVI-only group and in 25 (37.3%) patients in the SVC-group (Chi-square test p < 0.001). There were no persistent PNP cases. Bradycardia or junctional rhythm was observed during a procedure in 15 (22.4%) patients who received SVC isolation. One patient eventually received a permanent AAI pacemaker due to a sinus node injury.

Conclusion

Our data suggest that SVC isolation can be successfully achieved in the majority of PAF patients using conventional cryoballoon. However, this significantly increases the rate of transient or impending PNP and sinus node injury in comparison to conventional cryoballoon PVI. Therefore, careful phrenic nerve function monitoring and attention to sinus bradycardia or junctional rhythm are important to mitigate this risk. Follow-up data are being collected to determine whether this risk could be outweighed by a lower rate of PAF recurrence.
Pulmonary hypertension is associated with increased recurrence of atrial fibrillation post-pulmonary vein isolation: a multicenter study insights
Authors: Massalha E , Shimoni O , Sabbag A , Nof E , Beinart R
Published: May 2024

Background

Pulmonary vein isolation (PVI) has become an essential therapeutic approach for managing paroxysmal and persistent atrial fibrillation. Besides the fact its application increases, a substantial proportion of patients will suffer from arrhythmia recurrence.

Objectives

This study aims to determine the clinical and echocardiographic factors that predict fibrillation recurrence following pulmonary vein isolation.

Methods

In this prospective, multicenter study carried out across 14 medical centers in Israel, we included a cohort of 1002 patients who underwent pulmonary vein isolation from 2019 to 2022. The study involved an assessment of patients' baseline characteristics, electrocardiographic and echocardiographic data, laboratory results, details of the procedure, and their clinical outcomes. We monitored these clinical outcomes for one year after the ablation procedure, focusing mainly on the recurrence of atrial fibrillation, which was verified using electrocardiographic evidence during the post-blanking period. A multivariable analysis revealed the clinical and echocardiographic predictors for atrial fibrillation recurrence post-PVI.

Results

Our study evaluated 1002 patients with an average age of 64.4 ±11.3 years, including 37.5% females (376 patients). The cohort predominantly, about two-thirds, had paroxysmal AFIB, with an average arrythmia duration of 4.1 years. Frequent pre-existing conditions included ischemic heart disease in 17.3% and congestive heart failure in 13.8% of the patients. Additionally, diabetes was present in a quarter of the cohort, with 9% having a prior cerebrovascular event. The median LVEF was 60 (IQR 53-60), and the average left atrial diameter was 42.6 mm±8.8. The median pulmonary artery pressure was noted at 31 (IQR 25-38), with 13% of patients exhibiting elevated levels above 45 mmHg. Within the first year after the ablation, 11.7% of patients experienced AFIB recurrence in the post-blanking period. Our multivariate COX analysis established clinical and echocardiographic models for predicting post-PVI AFIB recurrence. Gender was a significant predictor, with women showing a higher recurrence rate (HR 1.85, 95% CI 1.29-2.7, P<0.01), in addition to persistent AFIB and a non-sinus rhythm at the time of the procedure. Echocardiographic predictors of recurrence included a left atrial diameter greater than 40 mm (HR 2.16, 95% CI 1.3-3.6, P<0.01) and pulmonary hypertension, notably when pulmonary artery pressure exceeded 55 mmHg, which correlated with almost a fourfold increase in AFIB recurrence risk within the first-year post-procedure (HR 4.25, 95% CI 1.57-11.5, P<0.01).

Conclusions

Pulmonary hypertension, especially with pulmonary artery pressure above 55 mmHg, significantly elevates the risk of atrial fibrillation recurrence post-pulmonary vein isolation, underscoring its importance in patient prognosis and management.
Evaluation of heart rate variability at 1-month after pulsed field ablation of atrial fibrillation and comparison with radiofrequency ablation
Authors: Vio R , Forlin E , Quinto L , Vitale R , Marras E , Corrado A , Themistoclakis S , China P
Published: May 2024

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<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