bluuebunny/crossref_metadata_2025 huggingface dataset:
Bipolar catheter ablation for highly refractory cardiac arrhythmia - does the success rate depend on arrhythmia origin?
Authors: Gardziejczyk P , Piotrowski R , Krynski T , Sikorska A , Kulakowski P , Baran J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Despite technological progress, some arrhythmias are still refractory to standard unipolar ablation. They include arrhythmias arising from left ventricular (LV) summit, cardiac crux or epicardium. Bipolar ablation may be useful in some cases, however, data on efficacy of this approach in various arrhythmia localisatons are scarse.

Purpose

Aim of the study was to assess efficacy of bipolar catheter ablation in patients with cardiac arrhythmias refractory to standard ablation approach.

Methods

Observational, single-center study was conducted over 30-month period. Twenty-six consecutive patients (male=18, aged = 54.26 ± 16.4) who were referred for bipolar ablation were included. All patients had a history of previously failed unipolar ablation procedures. Bipolar ablations were performed using dedicated RF generator and electroanatomic mapping system.

Results

Twenty-seven procedures in 26 patients with a mean of 2.52 ± 0.83 previously failed unipolar ablations were included in the final analysis. There were 4 ablations of accessory pathways (3 postero-septal and 1 left free wall) with acute success rate of 100%, 11 procedures of ventricular arrhythmias originating from crux of the heart with acute success rate of 73% and 12 from left ventricular summit (LV summit) with acute success rate of 50%. Mid-term success rate (median follow-up of 182 days) was 100%, 63% and 50% respectively. There was one major complication (not related to RF bipolar ablation): cardiac tamponade due to aortic cusp rupture requiring urgent cardiac surgery procedure.

Conclusions

Bipolar ablation is a promising method of catheter ablation for refractory arrhythmias. The highest success rate was observed in ablation for difficult pathways, followed by ventricular arrhythmias originating from cardiac crux and LV summit.
Wide antral circumferential re-ablation in case of recurrent atrial fibrillation despite of prior pulmonary vein isolation increases freedom from atrial tachyarrhythmias
Authors: Makimoto H , Gerguri S , Hartl S , Kluge S , Clasen L , Bejinariu A , Brinkmeyer C , Schmidt J , Kelm M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Despite repeated pulmonary vein isolation (re-PVI) due to recurrent atrial fibrillation (AF) after PVI has been a standard procedure, the detailed ablation strategy in case of re-PVI remains disputable.

Objective

The aim of this study was to assess the efficacy of re-PVI using wide antral circumferential ablation (WACA) supported by high density mapping (HDM) for recurrent AF after PVI as compared to simple repeated PVI supported by circular mapping catheter.

Methods

Consecutive patients with recurrent AF after PVI were prospectively enrolled in this study, who underwent left atrial HDM and subsequently WACA antral (re-)isolation ("Re-WACA" group). The historical controls with re-PVI between 2016 and 2018 using circular mapping catheter, but without HDM were also enrolled ("control group"). These control patients underwent re-PVI with gap ablation at the pulmonary vein ostium. Primary endpoint was defined as any recurrence and ECG documentation of atrial tachyarrhythmias (AT) including AF or atrial tachycardias over 30 seconds. The patients were routinely followed up for 1 year with at least twice annual holter-monitoring.

Results

In total, 116 patients were enrolled in this study (Re-WACA group [N=56, 68±10 years], control group [N=58, 65±10 years]). There were no significant differences in clinical characteristics including the number of previous left atrial ablation procedures between two groups. In all 56 patients with Re-WACA, residual PV antral potentials were demonstrated (100%), whereas 7 patients (13%) showed no electrical potentials inside any PVs. During a mean follow-up period of 402±71 days, 6 out of 56 Re-WACA patients (11%) and 18 out of 58 controls (31%) experienced AT recurrences. Kaplan-Meier analysis demonstrated that the patients who underwent Re-WACA showed significantly lower AT recurrence after the index Re-PVI procedure as compared to the controls (log-rank, P = 0.010). Multivariate Cox regression showed that Re-WACA was an independent predictor of freedom from AT recurrence (hazard ratio = 0.39; 95% confidence-interval 0.16-0.93; P=0.034). The number of previous PVI procedures predicted AT recurrence during follow-up (hazard ratio = 2.35; 95% confidence-interval 1.20-4.46; P=0.010).

Conclusions

Residual pulmonary vein antral potential in patients with recurrent AF after previously performed PVI is a frequent finding. These antral potentials can be easily visualized by HDM. Repeated isolation of wide PV antrum (Re-WACA) is an effective strategy to reduce further AF recurrence as compared to conventional re-PVI without left atrial HDM.
Safety and efficacy of very high-power short-duration ablation for pulmonary vein isolation
Authors: Schillaci VS , Strisciuglio TS , Stabile G , Arestia AA , Agresta AA , Shopova GS , Salito AS , De Simone ADS , Solimene FS
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

A very high-power short-duration (vHPSD) strategy of radiofrequency (RF) ablation aims to minimize conductive heating and increase resistive heating.

Purpose

The aim of our study is to evaluate the feasibility, efficacy and safety of the vHPSD ablation of the for pulmonary vein (PV) isolation in patients presenting with paroxysmal or persistent atrial fibrillation (AF).

Methods

This prospective non-randomized study enrolled consecutive AF patients undergoing PV isolation. The vHPSD ablation was performed with the QDOT catheter, applying 90 W, for 4 s, with an irrigation of 8 ml/min. RF was delivered targeting interlesion distance ≤ 6 mm. The PVI was assessed at the end of the encirclement with the Pentaray catheter by entrance block and by remapping.

Results

Overall 163 patients (29 with persistent AF) were enrolled. The mean age was 61±8 years, 60% had hypertension and 10% diabetes mellitus. PV isolation was obtained in all patients and at first-pass in 144 (88%) with a mean number of 83±15 RF pulses. The mean procedural time was 85±26 min, the mean fluoroscopy time was 9±6 min and the mean RF time was 5,5±1 min. In 5 patients (3%) access-related vascular complications occurred. The mean follow-up (fu) was 8±3 months (fu³6 months in 109 patients; fu³12 months in 15 patients) and the freedom from AF recurrence was 97% in the overall population and in the paroxysmal and persistent subgroups as well (Figure 1).

Conclusions

The vHPSD ablation represents an effective and safe ablation strategy to achieve PV isolation in paroxysmal and persistent AF patients.
Catheter ablation of the mitral isthmus line using the novel DiamondTemp ablation system: first experience using two different ablation protocols
Authors: Rottner L , Schleberger R , Lemoine M , My I , Moser F , Moser J , Dinshaw L , Kirchhof P , Ouyang F , Rillig A , Metzner A , Reissmann B
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Mitral ishmus ablation is an established approach to treat perimitral reentrant tachycardia, and is often performed as substrat modification in patients with persistent atrial fibrillation (AF). Bidirectional block of the mitral isthmus line (MIL) is still a great challenge using conventional ablation catheters, but is essential to prevent recurrence of atrial arrhythmia.

Recently, the novel DiamondTempTM (DT) ablation system was introduced and allows for high-power, short-duration ablation in a temperature-controlled mode. Its use during pulmonary vein isolation (PVI) using a recommended ablation setting with a catheter-tip temperature limit of 60°C, a temperature-controlled power of 50 W and an application duration of 10 sec has shown to be effective and safe. However, data on DT ablation settings for substrate modification, i.e., creation of linear lesions are lacking.

Aim

The aim of the present study was to evaluate acute efficacy and safety of the novel DT ablation system for bidirectional block of the MIL using two different protocols.

Methods

The study population comprised 14 patients [67±8 years, 10/14 male (71%)] suffering from persistent AF and/or atrial tachycardia who underwent catheter re-ablation with creation of a MIL using the DT ablation system. Ablation settings were a catheter-tip temperature limit of 60°C, a temperature-controlled power of 50 W with an application duration of either 10 sec (group A, n=7) or 20 sec (group B, n=7). Additional epicardial ablation from within the coronary sinus with a temperature limit of 60°C, a temperature-controlled power of 20 W and an application duration of 20 sec was performed, if bidirectional block could not be achieved with endocardial ablation only.

Results

Mean procedure and fluoroscopy time, and dose area product for group A and group B were 103±24 vs. 119±38 min, 12±5 vs. 13±4 min, and 572±270 vs. 537±202 cGycm, respectively. Bidirectional block of the MIL was achieved in 7/7 (100%) patients in group A and in 6/7 (86%) patients in group B. Additional epicardial ablation was required in 6/7 patients (86%) in group A and in 4/7 (57%) patients in group B. In group B, bidirectional block of the MIL required fewer endocardial (31±11 vs. 26±10 applications) as well as epicardial RF-applications (10±6 vs. 7±3 applications). Pericardial effusion without hemodynamic relevance occurred in 1/7 (14%) patients of group B. No further complications occurred.

Conclusion

Catheter ablation of the MIL using the novel DT ablation system is safe and associated with high acute efficacy. A lower number of RF-applications and a less frequent need for additional epicardial ablation was observed when applying longer RF-applications of 20 sec. Further analyses are warranted to confirm these findings.
Contemporary management of arrhythmias in pregnancy: efficacy and outcomes of catheter ablation without fluoroscopy
Authors: Abdrakhmanov A , Ainabekova B , Nuralinov O , Bakytzhanuly A , Smagulova A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Heart rhythm disorders are the most common cardiac complication occurring in pregnancy. Haemodynamically unstable and drug refractory arrhythmias warrant catheter ablation. However, there are little data of efficacy and outcomes of catheter ablation in pregnant women.

Purpose

To assess efficacy and outcomes of catheter ablation without of fluoroscopy in pregnant women.

Methods

This single center, prospective study included all cases of catheter ablation during gestation (n=48, study group) and pregnant women with antiarrhythmic drug therapy (n=50, control group). Complications, pregnancy course, obstetric and neonatal outcomes were determined and compared.

Results

The most common reported arrhythmias in both groups was supraventricular tachycardia (n=39; 81% vs n=31; 62%, p=0.045). Premature contractions was in 13% cases in study group and 32% in control group (p=0.029). Ventricular tachycardia was rare during pregnant (n=3; 6% vs n=3; 6%, p=1.0). All ablation procedures were performed without fluoroscopy (mean gestation age 24,21±3,32 weeks, mean procedural time of 71±15 minutes). In one women in study group occurred ileofemoral thrombosis, which was treated successfully. Pregnancy course was benign in all women in both group without termination. Uterine blood flow violation was in 12.5% in study group and in 8% - in control (p=0.520). Increased uterine contractility occurred only in women with catheter ablation (n=2; 4.2%, p=0.237). Type of delivery was vaginal in the majority in both groups (n=36; 75% vs n=40; 80%, p=0.553). Operative delivery was rare (n=12; 25% vs n=10; 20%, p=0.553), mainly due to obstetric indications. In 2 cases in study group were placental abraption (vs n=0, p=0.237) and preeclampsia (vs n=1; 2%, p=0.613). There were live births in all cases without maternal and fetal mortality. During 1 year follow-up there was no arrhythmia recurrence in study group.

Conclusions

Catheter ablation in pregnant women is safe and effective and can be performed without fluoroscopy. Majority of women with arrhythmias have benign course of pregnancy and perinatal outcomes
Repeat procedures and reconnection rates after cryoballoon PVI with phrenic nerve injury
Authors: Heeger CH , Sohns C , Pott A , Metzner A , Inaba O , Straube F , Kuniss M , Aryana A , Miyazaki S , Chun JC , Kuck KH , Dahme T , Steven D , Sommer P , Tilz RR
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Aims

Cryoballoon (CB) based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury which is leading to premature abortion of the freeze cycle. Here we analysed repeat procedures and reconnection rates after CB-based PVI and phrenic nerve injury in a large-scale population. Due to the fact that the freezing process was prematurely interrupted the data may offer unique findings in optimizing the CB dosing protocols.

Methods and Results

In the YETI registry a total of 17356 patients underwent CB-based PVI in 33 centers and 731 (4.2%) patients experienced phrenic nerve injury. A total of 111 / 731 (15.2%) patients received a repeat procedure utilizing a 3D mapping system due to AF recurrence. In 94/111 (84.7%) of patients data on repeat procedures was available. During their initial PVI procedures, phrenic nerve injury occurred during treatment of RSPV (n=80), RIPV (n=13) and LSPV (n=1). A total of 89/94 (94.7%) target PVs have been isolated during the initial PVI (RSPV: 75/80, 94%; RIPV: 13/13; 100%; LSPV: 1/1; 100%). The mean freezing time was 127±46s and the mean minimal temperature was -49±7°C. During the repeat procedures 67 of initially 89 isolated PVs showed persistent isolation (75%, for RSPV: 55/75; 73%; RIPV: 11/13; 85%; LSPV: 1/1; 100%).

Conclusion

In patients initially treated by CB-based PVI with interruption of the freezing due to phrenic nerve injury, a high rate of durable isolated PVs has been detected at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures
Relationship between the posterior Atrial Wall and the ESOphagus: esophageal position and temperature MEasurement during Atrial Fibrillation ablation. (AWESOME-AF)
Authors: Teres C , Soto-Iglesias DS , Penela DP , Jauregui BJ , Ordonez AO , Chauca AC , Carreno-Lineros JMCL , Scherer CS , Huguet MH , Ramirez-Paesano CRP , Camara OC , Ortiz-Perez JTOP , Berruezo AB
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary Vein Isolation (PVI) implies unavoidable ablation lesions on the left atrial posterior wall (LAPW), which is closely related to the esophagus, resulting in several complications.

Objective

To evaluate the usefulness of the esophageal isodistance print in avoiding temperature rises caused by radiofrequency (RF) application at the LAPW during paroxysmal AF ablation.

Methods

An isodistance map of the atrio-esophageal relationship (esophageal fingerprint) was derived from the preprocedural multidetector computerized tomography MDCT. Patients where randomized on a 1:1 basis in two groups. The PRINT group had a modified PVI line based on the esophageal fingerprint. The CONTROL group underwent standard PVI, and the operator was blinded to the fingerprint (Figure A). Primary endpoint was temperature rise detected by the intraluminal esophageal temperature monitoring probe. The esophageal probe position was verified with the fluoroscopy. Ablation settings were as specified on the Ablate BY-LAW protocol.

Results

60 consecutive patients [42 (70%) men, mean age 60±11 years] referred for paroxysmal AF ablation were randomized. As shown in figure B, a temperature rise (>39,1ºC) occurred in 5 (16%) patients on the PRINT group Vs. 17 (56%) on the CONTROL group (p<0,01).

Conclusion

The esophageal fingerprint allows for a reliable identification of the esophageal position and its use is superior to standard approach in avoiding esophageal temperature rises. The development of new imaging-derived tools can improve patient safety. Long term follow-up is needed to evaluate for impact of PVI line modification on outcomes in terms of AF recurrence.
Early recurrences after catheter ablation for atrial tachycardia: do we need a blanking period?
Authors: Kahle AK , Jungen C , Scherschel K , Alken FA , Meyer C
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

A blanking period after catheter ablation for atrial fibrillation is widely accepted. The clinical implications of early recurrences (ER) after ablation for atrial tachycardia (AT) in patients with a history of atrial fibrillation have not been analysed so far.

Purpose

To characterise ER and their relationship with late recurrences (LR) after AT ablation.

Methods

Acute and long-term outcome was studied in a total of 250 patients undergoing catheter ablation for consecutive AT. ER were defined as any documented atrial arrhythmia >30 s within 3 months after ablation.

Results

In our study population (66.5±0.7 years, 57.6% male), ER were detected in 80 patients (32.0%), with 74.0% of episodes occurring during the first month post-ablation. Patients with ER had a longer history of any atrial arrhythmia (9.1±0.9 years vs. 6.5±0.4 years; P=0.0283), a larger left atrial diameter (65.7±3.1 mm vs. 49.4±1.4 mm; P=0.0163) and a lower left ventricular ejection fraction (50.8±1.1% vs. 56.6±0.6%; P<0.0001) than those without ER. In patients with ER, AT were more often found to be mitral isthmus-dependent (16.5% vs. 6.2%; P=0.0048) or located at the crista terminalis (3.7% vs. 0.4%; P=0.0343). ER were associated with a 6.0-fold (95% CI 3.27-10.81; P<0.0001) and a 4.3-fold (95% CI 1.72-10.72; P=0.0023) increase in the risk of developing LR after a single or multiple ablation procedures, respectively (Figure). After a mean follow-up of 570±23 days, LR were detected in 78.0% vs. 76.9% vs. 50.0% of patients experiencing the first ER during the first, second or third month (P=0.2266). Among these groups, the first LR occurred after 188.7±20.2 days vs. 259.6±59.1 days vs. 400.8±55.5 days (P=0.0459).

Conclusions

ER after AT ablation are a predictor of LR and clinical as well as procedural risk factors are associated with the occurrence of ER. The prevalence of LR does not differ among patients with early vs. late ER. These findings underline the prognostic importance of ER and challenge the concept of a blanking period after catheter ablation for AT in patients with a history of atrial fibrillation.
Safety and feasibility of a novel multilectrode array catheter in mapping atrial and ventricular arrhythmias with high density: results from the multi-center OPTIMUM study
Authors: Vijgen J , Rackauskas G , Dilling-Boer D , Sarkozy A , Ciconte G , Vicedomini GG , Pappone C
Published: May 2022

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): This study was funded by Biosense Webster, Inc.

Background/Introduction

The novel multielectrode array mapping catheter includes 48 electrodes symmetrically distributed across and along 6 splines (Picture), with an additional unipolar reference electrode to reduce far-field signals built in at the tip of the irrigation lumen. Preclinical studies demonstrated its ability to provide high density and high resolution mapping in complex substrates, but its usability and safety in patients with atrial or ventricular arrhythmias have not been investigated.

Purpose

To assess the safety and mapping performance of the catheter with the electroanatomical navigation system for mapping in the atria and ventricle in patients with a variety of complex arrhythmias.

Methods

The OPTIMUM study was a prospective, single arm study conducted at 3 European sites. Patients with scar-related atrial tachycardia (AT), PAF and persistent AF (PsAF), ventricular tachycardia (VT), or premature ventricular complexes (PVC) underwent pre-ablation mapping with the study catheter, and subsequent ablation according to institutional standard of care practice; the follow up period was 7 days. The primary safety endpoint was the incidence of device-related serious adverse events (SAE) within 7 days following the procedure. The primary effectiveness endpoint was the completion of protocol-required fast activation and electro anatomical pre-ablation mapping without resort to non-study mapping catheter(s), including fast anatomical mapping, mapping of substrate or any area of interest, and identification of conduction channel(s), gap(s) and critical isthmuses. General procedural characteristics as well as physician feedback (7-point Likert scale: 1 = poor and 7 = excellent) on various aspects of deployment, signal quality, and learning curve were also evaluated.

Results

Thirty-one patients (mean age: 59.8±14 years, 71.0% male) were enrolled and treated (9 scar-related AT, 12 PAF, and 1 PsAF, 6 VT, and 3 PVC). There was no (0/31) SAE reported, and the primary effectiveness endpoint was achieved in all subjects (31/31). Almost all operators rated highly (≥ 5) on noise reduction in bipolar maps (30/31) and short learning curve (27/31). Bipolar signals and catheter maneuverability were rated highly favorable (≥5) in the left and right atria and met-expectation-and-above (≥4) in the left and right ventricles.

Conclusion(s)

The first-in-human clinical data demonstrate the safety and effectiveness of the novel microelectrode array mapping catheter to efficiently map various atrial and ventricular complex arrhythmias with good signal quality. Physicians indicated high satisfaction with the learning curve, catheter maneuverability, tissue characterization in all cardiac chambers.
Effectiveness and safety of bipolar ablation of heart arrhythmia. A systematic review with meta-analysis
Authors: Farkowski M , Truszkowska N , Zielinska A , Karlinski M , Futyma P , Pytkowski M , Hryniewiecki T , Maciag A
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The National Centre for Research and Development, Poland

Introduction

Bipolar radiofrequency ablation (BFRA) emerged as a viable technique of radiofrequency ablation where the standard unipolar approach (RFA) failed. A number of studies describing BRFA were published recently suggesting high effectiveness and acceptable safety of this technology for ablation of ventricular tachycardia in structural heart disease (SHD VT), premature ventricular contractions (PVC) or atrial flutter (AFL).

Purpose

We performed a systematic review with meta-analysis of available evidence to assess contemporary evidence on the effectiveness and safety of bipolar ablation of heart arrhythmia.

Methods

We systematically searched MEDLINE, EMBASE, and CENTRAL databases from inception to 27 August 2022 for prospective and retrospective studies with or without a control group. We also contacted BRFA experts to obtain information on the most up-to-date studies or conference presentations. Case studies and papers describing technical aspects of BRFA rather than clinical outcomes were excluded. Study quality was assessed using the Newcastle–Ottawa Scale.

Results

Out of 1919 records we included 12 studies: one good quality case-control study and 11 low-quality case series without a control group. Studies described 120 patients who received BFRA: mean age 61.9±10.3 years, 81% males, mean ejection fraction 43.2±12.4, SHD 62.6%, ICD/CRT-D 52.2%. Almost all patients were qualified to BRFA due to failure of at least one unipolar RFA. Follow-up period differed between studies and ranged between 1-2 years in most cases.

The overall acute effectiveness of BRFA was 88.2% (95%CI 82.5-93.8), I2=6.7%. The overall effectiveness of a first BRFA at the end of the follow-up period was 55% (95%CI 46.2-63.7), I2=7.2%. There was a need for a re-ablation in 21.2% patients (95%CI 11.2-31.2), I2=64%. A subgroup analysis for SHD VT, PVC and AFL yielded similar results. There were 16 serious complications including one surgical intervention and no acute deaths; five patients died during the follow-up, mainly due to heart failure progression.

Conclusions

Bipolar radiofrequency ablation may be an effective and safe procedure in selected patients who failed at least one unipolar radiofrequency ablation but the quality of the supporting evidence is generally low.
Learning curve for laser balloon ablation in the treatment of atrial fibrillation: a single center experience
Authors: Martignani C , Ziacchi M , Statuto G , Spadotto A , Angeletti A , Massaro G , Bartoli L , Cascioli G , Ginex S , Grassini D , Diemberger I , Galie N , Biffi M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Visually guided laser balloon ablation (LBA) is a promising method for pulmonary vein (PV) isolation in the treatment of atrial fibrillation (AF). To reduce procedural times, the rapid mode feature (RM), which offers an automated continuous 360° lesion for pulmonary vein isolation, was implemented in the latest version of the laser balloon system.

Purpose

We evaluated the learning curve for LBA in the treatment of AF

Method

We enrolled the first 74 patients with paroxysmal or persistent AF treated with LBA in our centre between September 2020 and December 2021. Exclusion criteria were any contraindication for the procedure. 3 different time intervals were considered (time 1 T1, time 2 T2 and time 3 T3), which included the first 25 patients, the next 25 patients and the last 24 patients, respectively. We compared fluoroscopy and procedural time and the number of pulmonary veins isolated by RM >90% (>324°) among the three group were compared.

Results

There was no difference between the three intervals in terms of age (61.2 ±9.00 vs 63.9 ±11.4 vs 58.4 ±12.9; p=n.s.), sex (68% vs 64% vs 81%; p=n.s.) and clinical characteristics. The procedural time (see picture 1) was significantly reduced from T1 to T2 (199 ±51.8 in T1 vs 159 ±38.6 in T2; p< 0.01), while there was no variation between T2 and T3 (159 ±38.6 in T2 vs 153 ±51.9 in T3; p=n.s.). We detected a reduction in fluoroscopy time between T1 and T2 (38.8 ±15.2 in T1 vs 28.8 ±10.5 in T2; p<0.01) but not further reduction was observed between T2 and T3 (28.8 ±10.5 in T2 vs 30.5 ±16.7 in T3; p =n.s.). Considering the use of (RM) feature, there was a progressive increase in the number of PVs isolated by RM >90% over time (1.0 ±0.7 PVs in T1 vs 2.0 ±1.2 PVs in T2 vs 3.3 ±0.9 in T3: p <0.01). Five pinhole balloon ruptures were observed, three in the T1 group, two in the T3 group. Temporary phrenic nerve dysfunction occurred in 1 patient in the T3 interval. No other complications were reported.

Conclusions

PV isolation by visually guided LBA is a safe procedure even during the learning curve. The system is user friendly and procedural time and fluoroscopy time reduced after a limited number of procedures.
Deep sedation with dexmedetomidine administered by electrophysiologists during COVID-19 pandemic compared with propofol administered by anesthesiologists for ablation of atrial fibrillation
Authors: Ebrille E , Lucciola MT , Amellone C , Ballocca F , Suppo M , Antonacci G , Gotta F , Birolo M , Orlando F , Favro E , Giammaria M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

COVID-19 pandemic, limiting the availability of anesthesiologists, has impacted heavily on the organization of invasive cardiac procedures such as transcatheter atrial fibrillation (AF) ablation.

Purpose

We compared the safety and efficacy of deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision, against the standard protocol performed with propofol.

Methods

We retrospectively included all AF ablation procedures performed in 2020: 23 patients sedated with 1% propofol (2 ml bolus followed by infusion starting at 1 mg/Kg/h), 26 patients with dexmedetomidine (infusion starting at 0.7 mcg/Kg/h). Both groups additionally received 1 mcg/Kg of midazolam as a single bolus and 0.05 mg single boluses of fentanyl prior to ablation on each pair of pulmonary veins (PV). Primary outcomes were oxygen desaturation (< 90%) or need for assisted ventilation/intubation, bradycardia (heart rate < 45 bpm) and persistent hypotension (systolic blood pressure < 90 mmHg).

Results

Baseline characteristics and hemodynamic variables did not differ between the two groups (all p > 0.05). In 8/23 (35%) patients propofol infusion velocity reduction was necessary to maintain the hemodynamic values, compared to 7/26 (27%) with dexmedetomidine.

Inter-group comparison of hemodynamic variables during the procedure showed no statistically significant difference, despite a trend in favor of dexmedetomidine (3 respiratory depressions and 3 persistent hypotension episodes with propofol vs. 0 with dexmedetomidine; p = 0.057).

Conclusion

Deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision is safe and effective for AF transcatheter ablation. A trend towards a lower incidence of hypotension and respiratory depression was noted when compared to propofol.
Impedance spike cut-off enhances safety of CLOSE-protocol guided ablation of atrial fibrillation
Authors: Krahnefeld O , Agdirlioglu T , Poley P , Weil J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation (CA) with radiofrequency (RF) energy using the CLOSE protocol has proven safety and efficacy in a large prospective multicenter study (1) with a rate of pericardial tamponade (PT) as low as 0.9%, thus with lower PT risk than reported by previous register data for PVI (2). PT may still become hazardous in the era of uninterrupted anticoagulation and may require urgent surgical repair. Steam pop is the major cause of PT during PVI with RF ablation and is usually preceded by steep impedance rise measured between tissue and tip of the RF catheter. The STOCKERT SMARTABLATE RF Generator as a core part of technology for CLOSE protocol guided PVI offers the opportunity to automatically stop RF energy delivery within 0.5 seconds if catheter impedance rises above a predefined value: impedance spike cut off (ISCO). The standard – manufacturer recommended – value for ISCO is 50 Ohms per 0.5 seconds.

Purpose

To investigate the effect of reduced ISCO during CLOSE protocol guided catheter ablation of AF on the occurrence of acute PT and pericardial effusion (PE) in a large single center series.

Methods

We performed CLOSE protocol guided PVI procedures using Biosense Webster CARTO PRIME 3D navigation system, Smarttouch SF ablation catheter, VIZIGO steerable sheath, invasive blood pressure measurement via radial artery. We changed the STOCKERT SMARTABLATE generator settings to ISCO of 25 Ohms per 0.5 seconds. Cut off during ablation by ISCO led the operator to reduce contact force, angulation/orientation of catheter/steerable sheath, changing to jet ventilation if mechanical ventilation was present. A retrospective analysis of all procedures was performed. Investigation for PT by echocardiography was performed for every drop < 90mmHg systolic blood pressure, immediately after and one day post ablation. Statistical analysis was performed on the evaluable population.

Results

During 31 months of observation we performed 627 CLOSE protocol guided procedures: 409 PVI only, 218 PVI with additional ablations (cavotricuspid isthmus, slow pathway, additional LA lines, ethanol ablation of vein of marshall). We observed 3 (0.5%) PT immediately at the end of the procedure and no additional relevant PE the day after CA. Of the 3 PT, one patient needed urgent surgical repair and two were managed conservatively with pericardiocentesis and retransfusion.

Conclusions

CLOSE protocol guided PVI is a very effective and safe intervention for treatment of AF. In the multicentre VISITAX trial, the rate of PT was reported with 3 events per 329 patients (0.9%). By reducing ISCO to 25 Ohms per 0.5 seconds, we could half the rate of PT found in the VISITAX trial. The generator cut off at ISCO of 25 Ohms per 0.5 seconds indicates a potentially dangerous position for ablation. Our data are limited due to the retrospective monocentric design and therefore the aformentioned approach should be evaluated prospectively.
Systematic identification of low voltage-high frequency electrogram zones at sites of left atrial reentrant tachycardia termination
Authors: Merino JL , Kim S , Sanroman M , Castrejon S , Relan J , De La Vieja Alarcon JJ , Martinez Cossiani M , Cervantes C , Carton A , Rivero Santana B , Tauber Molina P
Published: May 2022

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott

Background

Localization of the narrow isthmus of conduction of left atrial local and macro reentrant tachycardia (LAMRT) circuits within scar tissue is challenging. (Panel A). Near-field (NF) electrograms are often obscured by and difficult to distinguish from far-field (FF) activation. The peak frequency (PF) associated with bipolar electrograms is a novel parameter which may distinguish between NF and FF signals. (Panel B). However, the potential value of PF for LAMRT ablation has never been evaluated.

Purpose

1) To quantify the percentage of LA surface with low voltage (LV) and NF signals. 2) To study the proportion of LAMRT ablation sites which were located within a LV-NF region or in the vicinity of it (<10 mm away).

Methods

LART bipolar voltage and activation maps were generated with a 16-pole grid catheter (HD-Grid) during tachycardia. (Panels A,B). PF maps were retrospectively computed (Panels C,D). LV zones were defined according to a cutoff <0.3mV. Four different PF cut-off values (>250, >300, >350 and >400 Hz) were assessed in the delineation of overlapping LV-NF regions. (Panel E)

Results

16 consecutive patients with 24 LAMRT’s targeted for ablation were prospectively enrolled. 21/24 LAMRT’s were terminated by radiofrequency application. (Panel F). The LV area represented 47.7±14% of the LA surface. The LV-NF area represented 8.2±6.2%, 5.2±5.4%, 3.4±7.4% and 3.3±4.1% of the LA surface by using 250, 300, 350, and 400 Hz PF cutoffs respectively. There were 2.1±1 (range 0-3), 0.9±0.8(range 0-3), 0.5±0.6 (range 0-2) and 0.5±0.6 (range 0-2) LV-NF areas per patient using 250, 300, 350 and 400 Hz PF cutoffs respectively. At the optimal PF cutoff > 250Hz and voltage < 0.3mV, the site of tachycardia termination by radiofrequency application was found inside of a LV-NF region in 13/21 LAMRTs (sensitivity 68.4%), and within 1cm of a LV-NF region in 19/21 LAMRTs (sensitivity 89.5%) respectively.

Conclusion

1. Left atrial reentry termination sites by radiofrequency application are often within or nearby LV-NF areas as identified by the PF and voltage analysis of bipolar electrograms. 2. Beyond conventional substrate mapping, the systematic identification of high frequency activity within the low voltage zone holds promise for rapid identification of isthmus conduction critical to LAMRTs.
Correlation of local impedance, global impedance and contact force with resulting lesion size in RF ablation
Authors: Wachter A , Bahlke F , Popa M , Foerschner L , Krafft H , Maurer S , Telishevska M , Englert F , Lengauer S , Kottmaier M , Lennerz C , Reents T , Hessling G , Deisenhofer I , Bourier F
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

During clinical application of RF-energy, several parameters are constantly observed, e.g. RF time, power, global impedance and temperature. The new parameter "local impedance" is gaining importance and might be a possible real-time marker for predicting long-lasting RF-lesions and increasing safety. The aim of this study was to investigate the correlation between local and global impedance as well as RF power and contact force.

Methods

RF-lesions were created using an ex vivo model with porcine cardiac preparations. These were put in a saline-filled container with a dispersive electrode. Global impedance was held at 120 Ohm by adjusting saline and water. Additionally, a heated thermostat and a circulation pump were installed to imitate blood flow. RF-lesions were produced with different settings of energy and contact force (20, 30, 40 and 50 watts; contact force of 0-5g, 10-15g and 20-25g). While creating the lesions, global and local impedance, temperature, energy and RF time were documented, as well as the current lesion width and depth. Local and global impedance drops were calculated as the difference between baseline impedance and current impedance.

Results

In total, 1223 measurements were made during application of RF-energy. 6 steam pops occurred. Contact force, local and global impedance changes showed highly significant correlations with lesion depth and diameter. Amongst analyzed values, local impedance drop showed highest correlation with lesion diameter and depth (r = 0,391 and 0,613; p<0,001). Visualized in Figure 1 and 2, global and local impedance correlate with lesion diameter and depth.

Discussion

Local impedance was found to be a suitable real-time marker for lesion size, showing significantly higher correlations with RF lesion size than contact force and global impedance. Further investigation is necessary to find a cut off for a safe but long-lasting RF-lesion.
Arrhythmias in pregnant women without structural heart disease: characteristics and outcomes
Authors: Abdrakhmanov A , Ainabekova B , Nuralinov O , Bakytzhanuly A , Smagulova A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Heart rhythm disorders are relatively common in pregnant women. There are few data of arrhythmia characteristics and perinatal outcomes in patients without any structural heart disease.

Purpose

To describe the clinical peculiarities, pregnancy course and characterize outcomes.

Methods

A total of 99 pregnant without structural heart disease with arrhythmia was included, aged: 29.05±5.37years with a mean gestation age 22.7±7.29 weeks. Clinical characteristics, obstetric and neonatal outcomes were determined.

Results

The most common reported arrhythmias were supraventricular tachycardia (n=46; 46.5%) and premature contractions (n=36; 36.3%). Advanced heart block (n=9; 9.1%) and ventricular tachycardia (n=8; 8.1%) were rare during pregnant with structurally normal heart. The 56% of arrhythmia cases among the examined patients first occurred during current pregnancy. Studying the peculiarities of arrhythmia manifestations, it was determined that in the I trimester of pregnancy the disease symptoms appeared in 11% of the examined women, in the II trimester – in 59%, in the III trimester – in 31%. In the clinic, the most common symptoms of arrhythmia were palpitations (62.6%), general weakness (59.6%), dyspnea (38,4%) and dizziness (29.9%). Pregnancy course was benign in the majority of cases. Termination of pregnancy was in three cases (3%) – in one case due to extracardial cause, in two cases due to life threatening course of ventricular tachycardia. Premature birth was in 2 cases (2.02%). In 75% of pregnancy was vaginal delivery, in 25% - cesarean section. Preeclampsia was in 2 cases (2.02%). There were 99 live births without maternal and fetal mortality.

Conclusions

In pregnant women with no structural heart disease supraventricular tachycardia and premature beats are most common. Majority of patients have good course of pregnancy and outcomes.
Comparison of left atrial and atrial appendage mechanics to stratify the risk of left atrial/atrial appendage stasis in patients with non-valvular atrial fibrillation
Authors: Mao YANKAI , Zhao HJ , Yang YUAN , Ma MM , Yu CHAN , Wang YUNHE , Jiang RUHONG , Zheng ZHELAN , Jiang CY
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial appendage (LAA) and left atrial (LA) dysfunction are associated with the presence of thrombus and spontaneous echo contrast (SEC) within LAA. However, the role of LAA mechanical dispersion (MD) in contributing to thrombogenesis has not been fully addressed and compared with LA MD or LA/LAA GLS. We sought to investigate the relationship of LAA MD with LAA dense SEC or thrombus, and to compare its additional value with other LA/LAA mechanical parameters in patients with nonvalvular atrial fibrillation (AF).

Methods

We conducted a cross-sectional study of 493 consecutive patients with AF (median age 65, male 66.9%) who underwent echocardiography prior to catheter ablation. Of these, 70(14.2%) patients had dense SEC or thrombus in LAA. We measured the LAA and LA longitudinal strain using speckle-tracking echocardiography (STE). LAA MD and LA MD was defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval.

Results

Patients with LAA dense SEC/thrombus (n=70) had significantly higher LAA MD (median 14.20% (11.60%,16.80%) vs 9.35 % (6.23%,12.07%)) than controls (n = 423). Areas under the receiver-operating curve (AUC) for CHA2DS2-VASc score plus LAA MD, LAA GLS or LA GLS were comparable (0.843,0.830 and 0.809) and superior to that combined with LA MD (0.762, p<0.01). Multivariable analysis showed that LAA MD was an independent determinant of LAA dense SEC/thrombus in four different models (Odds ratio, 1.23-1.24; P < 0.001), and provided additional diagnostic value over clinical and standard echocardiographic parameters. Whereas LA MD was not significantly associated with LAA dense SEC/thrombus and had no incremental predictive value.

Conclusion

LAA mechanical dispersion provided incremental information over conventional risk factors in the identification of LAA dense SEC or thrombus in AF patients and is superior to LA mechanical dispersion.
Left atrium hemodynamic in atrial fibrillation and normal subjects
Authors: Falanga M , Masci A , Chiaravalloti A , Dal Monte A , Corsi C , Tomasi C
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

A computational fluid-dynamics (CFD) model previously developed with the aim of evaluating cardioembolic risk in patient affected by atrial fibrillation (AF) was used for the characterization of the left atrium (LA) hemodynamic in normal subjects (NL), patients affected by paroxysmal atrial fibrillation (PAR-AF) and patients affected by persistent atrial fibrillation (PER-AF). Based on the fluid-dynamics simulations results, we aimed at enhancing differences in blood flow in AF patients and NL and at better understanding the relationship between AF progression and stroke risk on a patient-specific basis.

Methods

3D patient-specific anatomical and motion models were derived from ECG-gated coronary artery CT acquired with retrospective protocol. These models represented the computational domain for CFD simulations in which inflow initial conditions were derived from PW Doppler at the mitral valve and at the pulmonary veins. Velocity field and vortex structures both within the LA and left atrial appendage (LAA) were assessed in 10 NL, 5 PAR-AF and 4 PER-AF. Blood stasis was evaluated by populating the LAA with 500 particles and counting the number of particles still present after five cardiac cycles.

Results

Velocities inside the LA and in the LAA presented different amplitude and distribution in the 3 groups (peak velocity – NL: 50÷60 cm/s, PAR-AF: 40÷50 cm/s, PER-AF: 15÷25 cm/s). The mean velocity resulted lower in the PER-AF compared with PAR-AF (mean velocity – PAR-AF: 25÷35 cm/s, PER-AF: 8÷20 cm/s) at the LAA ostium and inside the LAA, in which the wash-out effect was strongly reduced (Figure 1). On the other hand, the mean velocity in the NL was higher with respect of AF patients (mean velocity – NL: 40÷45 cm/s). A higher number of vortex structures was observed in NL compared with AF patients, thus favouring the hypothesis of a more efficient wash-out of the LA and of the LAA. Blood stasis in terms of number of particles in the LAA after five cardiac cycles confirmed these results (NL: 5±2, PAR-AF: 18±3, PER-AF: 41±10).

Conclusions

The developed approach quantifies differences in LA hemodynamic between AF and NL patients, also allowing a stratification of the atrial disease progression in terms of variations in the blood velocity, organization of blood flow and quantification of blood stasis.
Higher coronary calcium score is associated with increased risk of atrial fibrillation recurrence
Authors: Fernandes S , Ladeiras-Lopes R , Cruz I , Silva G , Diaz S , Barros A , Saraiva F , Faria R , Almeida J , Fonseca P , Goncalves H , Oliveira M , Ferreira N , Primo J , Fontes-Carvalho R
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Patients with atrial fibrillation (AF) referred for catheter ablation routinely undergo cardiac computed tomography (CCT) for procedure planning. An opportunistic evaluation of coronary artery calcium score (CACS) can be an important tool to improve clinical care. It is already known that CACS is associated with a high risk of AF development, particularly if values are above 100, but few data are available regarding the impact of CACS in AF recurrence after ablation.

Purpose

To assess the impact of CACS on atrial fibrillation recurrence following catheter ablation.

Methods

Retrospective, single-centre cohort study of consecutive patients with AF undergoing CCT for ablation procedure planning, from 2017 to 2019. Baseline clinical and demographical data were collected. Patients with known history of coronary artery disease (CAD) and moderate to severe valvular heart disease were excluded. CACS was assessed using the Agatston method. Recurrence was defined as any documented episode of AF, atrial flutter or atrial tachycardia after 3 months from procedure. Patients were stratified in CACS<100 and CACS≥100. Explorative analysis incorporated Kaplan-Meier survival curves and Cox regression.

Results

A total of 354 patients were included, with a mean age of 56 ± 12 years, 66% male and 21% with persistent AF. More than half of the patients had a CACS>0 (n=185, 52%) and 63 patients (18%) had a CACS≥100. Patients with CACS≥100 were older (63 ± 7 vs 54 ± 12 years, p<0.001), had higher prevalence of hypertension (68% vs 43%, p<0.001) and diabetes mellitus (21% vs 10%, p=0.012) and higher left atrial volume (39 ± 9 vs 35 ± 9 ml/m2, p=0.018). After a median observation time of 34 months (IQR 24-43), 117 patients (33%) had AF recurrence.

CACS≥100 was associated with increased risk of AF recurrence (unadjusted Cox regression: hazard ratio [HR] 1.85; 95% confidence interval [CI], 1.23-2.79, p=0.003) (Fig. 1). After covariate adjustment (age, gender, hypertension, diabetes mellitus, obesity, thyroid disease, AF type and left atria enlargement) CACS≥100 remained an independent predictor of the risk of AF recurrence (HR, 1.68; 95% CI, 1.05-2.70, p=0.03) as well as persistent AF (HR, 1.91; 95% CI, 1.23-3.00, p=0.004) (Fig. 2).

Conclusion

In patients with AF undergoing catheter ablation, without previous history of CAD, a CACS≥100 was independently associated with a 68% increase in the risk of AF recurrence.