bluuebunny/crossref_metadata_2025 huggingface dataset:
Zero-fluoroscopy ablation of the cavotricuspid isthmus guided by intracardiac echocardiography in patients with typical atrial flutter
Authors: Luani B , Ismail A , Kaese S , Pankraz K , Schmeisser A , Wiemer M , Braun-Dullaeus R C , Genz C
Published: October 2022

Introduction

In previous studies we have demonstrated the advantages of electrophysiology catheter navigation by intracardiac echocardiography (ICE). In this prospective study we investigated ICE-guided zero-fluoroscopy ablation of the cavotricuspid isthmus (CTI) involving a decapolar diagnostic and an irrigated radiofrequency (RF) ablation catheter in patients with typical atrial flutter (AFL).

Methods and results

Twenty-seven consecutive patients (mean age 73.4±11.6 years, 18 male) with ECG-recordings suggesting ongoing (n=19) or recent CTI-dependent AFL underwent an electrophysiological study (EPS) utilizing solely ICE for catheter navigation. All EPS could be successfully accomplished without the need for fluoroscopy. CTI-dependent AFL was confirmed by entrainment manoeuvre in all patients with ongoing AFL. Mean EPS duration was 44.0±20.3 minutes and mean ablation procedure duration was 22.3±16.4 minutes. RF ablation was applied for 6.3±3.1 minutes (50 Watts, irrigated RF-ablation in all patients). After the last RF application, bidirectional CTI-Block was confirmed by differential pacing in all patients. Echocardiographic parameters such as CTI-length, prominence of the eustachian ridge (ER), and depth of the CTI-pouch on the ablation plane (Figure 1) were assessed to analyse their correlation with EPS- or ablation procedure duration. CTI-pouch was shallower in patients with ablation procedure duration above median (4,9±1.09mm vs. 6.3±0.9mm, p=0.048), suggesting a more laterally ablation plane in these patients, where the CTI musculature is stronger. CTI-length or ER-prominence above the respective median did not correlated with longer EPS duration. However, in some cases with prominent ER inversion of the ablation catheter was needed to achieve contact of catheter-tip to the tissue. An asymptomatic intramural hematoma was diagnosed by ICE after successful ablation in one patient, no other major or minor complications were documented in this study.

Conclusions

Zero-fluoroscopy CTI ablation guided solely by intracardiac echocardiography in patients with CTI-dependent AFL is feasible and safe. ICE visualisation may help to localize the optimal ablation plane, to detect and correct poor tissue contact of the catheter tip and recognise early potential complications during the ablation procedure.

Funding Acknowledgement

Type of funding sources: None.
Adverse events associated with PentaRay Mapping Catheter – MAUDE database analysis
Authors: Bandarupalli T , Mandapati R , Shah K , Bharadwaj R , Contractor T , Lakkireddy D , Garg J
Published: October 2022

Background

The 20 pole PentaRay Mapping Catheter is a high-definition mapping catheter with five soft, flexible spines providing better and faster acquisition. Despite its design, the catheter is not without glitches.

Objective

We queried the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database for adverse events related to the use of the PentaRay mapping catheter.

Methods

The Manufacturer and User Facility Device Experience (MAUDE) database was searched for reports received between October 1, 2019, to October 31, 2021, to capture all adverse events associated with PentaRay mapping catheter using the term “PentaRay” in the “brand name” section. The adverse events were adjudicated to various categories based on the review of the event description for each medical device report (MDR).

Results

A total of 159 events were reported in 148 MDRs during the study period. The most common device related issues were: damaged splines 18.2% (n=29), device entrapment 17% (n=27), thrombus on device 15.1% (n=24), foreign material on splines 8.8% (n=14), sensor error 3.8% (n=6). Of the patient related events, 13.8% (n=22) were pericardial effusion, 5% (n=8) cardiac arrest, 1.2% (n=2) coronary vasospasm/STEMI, 0.6% (n=1) heart block, 0.6% (n=1) air embolism, 0.6% (n=1) tear in pulmonary veins. These events lead to procedure abortion 27.7% (n=44) and procedural delay 11.3% (n=18).

Conclusion

Several issues have been reported with the PentaRay mapping catheter leading to to procedure abortion, delay and patients related adverse events. Understanding and troubleshooting may help improve patient outcomes.

Funding Acknowledgement

Type of funding sources: None.
Outcomes of additional substrate modification in de novo atrial fibrillation ablation
Authors: Aslam F , Al-Sadawi M A , Aleem S , Ijaz H , Jacob R , Cao K , Santore L , Almasry I , Singh A , Fan R , Rashba E
Published: October 2022

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Data regarding additional substrate modification has been conflicting, both in paroxysmal and persistent atrial fibrillation.

Purpose

To assess the effect of additional linear substrate modification during de novo AF ablation on AF recurrence.

Methods

We reviewed 1575 AF ablations in 1254 patients from January 2013 to June 2021 at a single academic medical center. There were 1096 de novo ablations. We defined substrate modification as linear ablations including cavotricuspid isthmus (CTI), superior vena cava isolation, intercaval line, mitral isthmus, and left atrial roof and floor lines. We evaluated clinical and procedural characteristics to identify risk factors for AF recurrence and complications. Patients were followed for a minimum of 6 months.

Results

The 1096 de novo ablations included 65.5% males with mean age 61.1 years, mean BMI 31.3, 81.8% paroxysmal AF and 18.2% persistent AF. There were four AF ablation subgroups: PVI alone (41.6%), PVI and CTI ablation (37.1%), PVI with CTI and additional substrate modification (15.6%), and PVI with substrate modification without CTI ablation (5.7%). Overall, AF recurred in 36.9% cases. AF recurrence with PVI only ablation was 41% compared to 32.7% in patients with PVI and CTI ablation (p=0.02). When looking at patients with paroxysmal and persistent AF, results were similar, with decreased AF recurrence with the addition of CTI ablation in both paroxysmal (37.3% v. 29.2%, p=0.03) and persistent AF (58.1% v. 40.0%, p=0.02). Additional substrate modification did not result in significant difference in outcome in either paroxysmal or persistent AF (Figure 1).

Conclusions

In de novo AF ablations, addition of CTI ablation to de novo PVI ablation is associated with lower AF recurrence in both paroxysmal and persistent AF. Additional linear substrate modification did not impact outcomes.

Funding Acknowledgement

Type of funding sources: None.
Usefulness of the synthesized 18-lead ECG in identify the origin of premature ventricular contractions
Authors: Matsumoto H , Kida H , Nakanishi R , Miyoshi M
Published: October 2022

Background

There are have been reports on the 12-lead ECG waveforms used to identify ventricular premature contractions (VPCs), but there are not enough algorithms. On the other hand, the synthesized 18-lead ECG adds the right-side chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9) to the 12-lead ECG.

Purpose

This aim of this study was to evaluate whether the waveforms of the 18-lead ECG are useful in predicting the origin of VPCs.

Methods

We studied 86 consecutive patients (age :61.8±16.0 years, male: 54.5%) enrolled from multicenter who underwent radiofrequency catheter ablation for VPCs. We retrospectively investigated the association between origin of the VPCs and characteristics of the synthetic 18-leads ECG.

Results

The 18-lead ECG showed a specific pattern for the VPC originating near the His-bundle. In 17 cases, the QRS morphology in V5R exhibited a QS pattern, and 13 of 17 cases had VPCs originating near the His-bundle. In the other 69 cases, V5R did not exhibit a QS pattern. ROC curve analysis showed that the QS pattern in V5R predicted VPC originating near the His-bundle with high accuracy: sensitivity 100.0%, specificity 94.5%, and AUC 0.98. Furthermore, the positive predictive value was 76.5% and negative predictive value 100.0%.

Conclusion

The QS pattern shown in V5R of the 18-lead ECG was a useful parameter for identifying VPCs originating near the His-bundle, which might be a good reference indicator during radiofrequency catheter ablation for VPCs.

Funding Acknowledgement

Type of funding sources: None.
Pulmonary vein isolation without fluoroscopy: results evaluation
Authors: Martinez Gomez E , Salgado Aranda R , Perez Castellano N , Serra B , La Rosa G , Chavez Ortiz I , Gonzalez Ferrer J J , Canadas Godoy V , Filgueiras Rama D , Jeronimo Baza A , Ferrandez Escarabajal M , Ramos Lopez N , Hennessey B , Perez-Villacastin Dominguez J
Published: October 2022

Introduction

From the outset, the use of Xray (XR) has been a critical component in both the guidance and development of arrhythmia ablation procedures. At present however, due to the complex nature of electrophysiology procedures, the use of XR in isolation is not sufficient to ensure procedural success. Subsequently, the use of non-fluoroscopic virtual mapping systems is essential. Currently, given the evolution of this technology and its essential nature for procedural guidance, it is worth asking whether the use of XR is indeed still necessary in the modern era. The objective of this study was to demonstrate that “zero-XR” ablation of complex arrhythmias such as atrial fibrillation is both possible and safe.

Methods

Between 2020 and 2021, a total of 116 patients admitted for pulmonary vein ablation were included in the study. Amongst these, 41 patients were prospectively included at our centre, in a protocol for point-by-point ablation of pulmonary veins without fluoroscopy, “zero-XR”. In addition to the non-fluoroscopic mapping system, the transseptal puncture was monitored by intracardiac ultrasound in all cases. The objective of the ablation was the complete isolation of the pulmonary veins. In some patients, at the discretion of the operator, the ablation of other substrates was added. For the remaining 75 patients in the study, the ablation was performed using conventional techniques without the limitation of the use of XR. The mean follow up was 12 months.

Results

The baseline characteristics of the patients, as well as the description of the procedure, are shown in the Table. There were no differences in the acute success rate or procedure time between the two groups. There was only one complication related to the procedure in the non-XR group consisting of pericardial effusion without cardiac tamponade. Regarding the recurrence rate at 12 months, it was higher in the group with fluoroscopy, without reaching statistical significance [n=0 in the group without fluoroscopy, n=2 (2.7%) in the group with fluoroscopy, p=0.15].

Conclusion

In our series, point-by-point ablation of atrial fibrillation without fluoroscopy proved to be a safe and feasible technique, with similar success rates when compared to conventional procedures using XR.

Funding Acknowledgement

Type of funding sources: None.
Initial experience with dielectric-based local tissue assessment for catheter ablation
Authors: Abeln B G S , Van Dijk V F , Balt J C , Wijffels M C E F , Boersma L V A
Published: October 2022

Background

Dielectric imaging systems can be used to guide catheter ablation for cardiac arrhythmia. Currently, the KODEX-EPD system can be used to acquire high-resolution anatomical data for electroanatomical mapping. Future software versions of this system enable tissue assessment utilizing local dielectric sensing. These dielectric-based tissue assessments (KODEX Vision) enable new features, including wall thickness measurement, catheter-tissue contact assessment, and ablation lesion assessment.

Purpose

To gain insight in the dielectric-based tissue assessment features.

Methods

The KODEX-EPD system was used to perform repeat ablations in patients with recurrent atrial fibrillation after pulmonary vein isolation. A primary system with the current software version (1.4.8) was used by the operator. Ablation was performed with a non-contact force-sensing irrigated radiofrequency catheter, with power set at 30–35W and aiming for ablation times of 30–60s. A secondary system was blinded for the operator and loaded with beta software (1.5.0) to enable the KODEX Vision features. Only successful local tissue assessments are presented in this abstract. All patients were enrolled in a prospective registry study which was approved by the local ethics committee.

Results

Electroanatomic mapping in 25 patients (age 65±8yr, male 84%, LAVI 31±9ml/m2) revealed electrical reconnection in 66 of 100 pulmonary veins. A total of 308 radiofrequency applications were used to re-isolate the veins and create additional lesions (superior vena cava isolation in 6, box lesion in 1). Wall thickness at the sites of ablation ranged from 1.3–3.9 mm. Tissue contact assessment at the start of RF applications indicated “touch” in 77%, while 17.5% and 5.5% of results indicated `no touch' or “high touch”. Tissue Response Viewer indicated low dielectric response in 18.5% and high dielectric response in 81.5% of results. High dielectric response was associated with lower wall thickness (OR: 0.86, 95% CI [0.76–0.97], p=0.014).

Conclusion

This preliminary evaluation underlines the potential of dielectric-based tissue assessment features. Wall thickness measurement, catheter-tissue contact, and ablation lesion assessment seem feasible with the beta software. Further evaluation of the feasibility, accuracy and clinical impact of the finalized software is warranted.

Funding Acknowledgement

Type of funding sources: None.
Clinical outcomes of high-density mapping for atypical atrial flutter ablation
Authors: Abeln B G S , Balt J C , Klaver M N , Maarse M , Van Dijk V F , Wijffels M C E F , Boersma L V A
Published: October 2022

Background

High-density mapping is increasingly used in catheter ablation of complex arrhythmias. In atypical atrial flutters (AAFl), high-density mapping can provide a more accurate delineation of the arrhythmic circuit. This promotes acute procedural success, but follow-up data on clinical outcomes are scarce.

Purpose

To study procedural characteristics and arrhythmia recurrence of high-density mapping-guided AAFl ablation.

Methods

In this monocenter prospective observational cohort study, we included patients that were treated for AAFl using a high-density mapping system with a grid-patterned mapping catheter. We evaluated acute procedural success and atrial flutter recurrence at follow-up. Acute success was defined as non-inducibility of atrial flutters. Arrhythmia recurrence was defined by electrocardiographic documentation of atrial flutter.

Results

Between April 2018 and July 2020, 65 patients (69% male; age 65±8yr; 69% prior PVI; 60% prior cardiac surgery) were included in this study. A total of 100 AAFl were observed during the procedures. The flutter circuit was unmappable for 14 flutters in 11 patients (17%). Critical isthmuses were identified and ablated in 32 patients (49%). Other ablation strategies included linear ablation lesions (i.e., roof in 25% of patients, box in 9%, anterior in 35%, left lateral mitral in 17%), re-PVI (11%), septal (8%) and right atrial (8%) ablation. Acute procedural success was achieved in 86% of the cohort. During a follow up of 1.5±0.7 years, 38% of the cohort had recurrence of an atypical atrial flutter for which 23% had a re-intervention (repeat flutter ablation in 11% patients and his ablation with pacemaker implantation in 14%). Atypical atrial flutter recurrence was associated with presence of an unmappable flutter (HR: 2.7, 95% CI [1.1–6.4], p=0.03) and critical isthmus ablation (HR: 0.40, 95% CI [0.17–0.93], p=0.03).

Conclusions

Despite high-density mapping, 38% of patients had recurrence of an AAFl at follow-up. Presence of an unmappable flutter was associated with atrial flutter recurrence while critical isthmus ablation was associated with freedom from atrial flutter recurrence.

Funding Acknowledgement

Type of funding sources: None.
Safety and efficacy of catheter ablation for atrial fibrillation in the very elderly
Authors: Wahedi R , Willems S , Jularic M , Hartmann J , Schaeffer B , Akbulak-Stegli Ö , Eickholt C , Anwar O , Maurer T , Hedenus K , Gunawardene M
Published: October 2022

Background

The incidence and prevalence of atrial fibrillation (AF) increases with age. With an ageing general population, a 2.3-fold rise in AF prevalence is expected. Catheter ablation has emerged as an effective treatment option for rhythm control therapy. However, very elderly patients (≥80 years old) have been excluded in landmark clinical trials. Current data regarding the safety and efficacy of catheter ablation in the very elderly is therefore sparse.

Purpose

Due to the growing demand to manage AF in an increasingly ageing population, we investigated the safety and efficacy of catheter ablation in this particular patient population.

Methods

Patients with symptomatic paroxysmal, persistent and long-standing persistent AF aged ≥80 years undergoing catheter ablation, including first and re-ablation procedures in a single centre, were analysed retrospectively. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency, cryoballoon and pulsed field ablation as energy sources. Re-ablation procedures included re-PVI and consecutive atrial tachycardia ablation including atrial lines and/or ablation of complex fractionated atrial electrograms (CFAE) in persistent AF. Endpoints included acute procedural success (complete isolation of pulmonary veins and/or non-inducibility in the case of atrial tachycardia), major complications and early arrhythmia-recurrence.

Results

A total of eighty-eight patients (mean age 83.1±1.9 years, mean CHA2DS2-VASc-Score 4.4±1, mean left ventricular ejection fraction 56.7±7%, direct oral anticoagulation 92.1%, vitamin-K antagonists 7.9%) were included from January 2021 to October 2021. Fifty cases (56.8%) involved PVI as an index procedure (radiofrequency 58%, n=29/50, cryoballoon 36%, n=18/50, pulsed field ablation 6%, n=3/50). Thirty-eight procedures (43.2%) involved re-ablation procedures (Re-PVI 60.5%, n=23/38, linear lesions 65.8%, n=25/38, atrial tachycardia ablation 26.3%, n=10/38 and ablation of CFAE 15.8%, n=6/38). Acute procedural success was achieved in 87/88 patients (98.9%). Major complications included stroke (n=1/88, 1.1%), pericardial tamponade (n=1/88, 1.1%) and bradycardia with subsequent pacemaker implantation (n=3/88, 3.4%). No further major complications were documented. In 13/88 patients (14.8%) early arrhythmia-recurrence occurred (38.5%, n=5/13 after the index procedure and 61.5%, n=8/13 after re-ablation) during the 90-day blanking period.

Conclusions

Catheter ablation for atrial fibrillation in the very elderly shows favourable acute success and low complication rates. Long term success of catheter ablation and superiority to rate control in this patient population is unknown and requires investigation in the future.

Funding Acknowledgement

Type of funding sources: None.
Safety and effectiveness of very high-power short duration ablation in patients with atrial fibrillation: early results
Authors: Mitrzak K , Krzowski B , Peller M , Maciejewski C , Marchel M , Balsam P , Grabowski M , Lodzinski P
Published: October 2022

Background

Pulmonary vein isolation (PVI) is at the forefront of treatment methods of rhythm control in patients with atrial fibrillation (AF) (1). The novel contact-force sensing catheter, QDot MicroTM (Biosense Webster) was designed to improve effectiveness of AF ablation and allow better time management due to shorter procedure time. It is a very high power-short duration (vHP-SD) catheter optimized for high density mapping and temperature control, which enables the application of high energy (up to 90W, 4s) (2).

Purpose

The aim of the study was to compare the QDot MicroTM catheter with the ThermoCool SmarttouchTM SF catheter with regard to the effectiveness and safety of PVI ablation.

Methods

It is a single center, cross-sectional, observational study enrolling 101 consecutive patients suffering from symptomatic paroxysmal or persistent AF, referred for first catheter ablation between 16 December 2019 and 03 December 2021. In 47 procedures (mean age 54 years; 70% male; 77% paroxysmal) the QDot Micro catheter was used (vHP-SD group; Qmode+ 90W, 4s), whereas the remaining 54 patients (mean age 57 years; 70% male; 67% paroxysmal) were treated with the ThermoCool SmarttouchTM SF catheter (control group, Ablation Index guided ablation). The primary endpoint was freedom from AF at 3-months after ablation. The secondary endpoints included the amount of opioids administered as well as the incidence of early-onset treatment-emergent adverse events (TEAEs).

Results

AF recurrence was documented in 14.9% patients in vHP-SD group and in 31.5% patients in control group (p=0.06). The mean dose of remifentanil was reported to be lower during Qmode+ catheter-based PVI (0.50 (0.40–0.60) vs. 0.70 (0.55–0.90) mg; p<0.001). There was no statistically significant difference in TEAEs between both groups (6.3 vs. 0%; p=0.10). One severe adverse event (cerebral vascular incident 2 days after PVI – due to thrombus in the left ventricle) was observed in vHP-SD group.

Conclusions

This study suggests that the vHP-SD ablation is safe and enables sedative-analgesic medications demand reduction during procedure. vHP-SD mode may enhance the success rate of catheter-based PVI, however further research is needed to provide additional evidence of its superiority.

Funding Acknowledgement

Type of funding sources: None.
An analysis of the influence of atrial wall thickness on the protective effects of proactive esophageal cooling during high-power short-duration radiofrequency ablation
Authors: Mercado Montoya M , Gomez Bustamante T , Berjano E , Hernandez Arango P , Mickelsen S , Schieber J , Kulstad E , Daniels J
Published: October 2022

Background

The use of proactive esophageal cooling using a dedicated cooling device during radiofrequency (RF) left atrial ablation has increased, with endoscopic studies showing reductions in esophageal lesions using medium power ablation settings. With no atrioesophageal fistula yet identified using esophageal cooling, and clinical practice increasingly shifting to high-power short-duration (HPSD) ablation, additional data on the protective potential of this technique in HPSD ablation may help guide RF ablation strategies. In particular, a better understanding of the effects of anatomical variations in myocardial thickness on cooling efficacy is warranted.

Purpose

We sought to evaluate the influence of atrial wall thickness on the protective effects of proactive esophageal cooling during HPSD ablation.

Methods

Using a computer model of the left atrium and esophagus, we analyzed the esophageal damage that occurs under two HPSD ablation conditions (50 W for 10 s and 90 W for 4 s) with and without proactive esophageal cooling while varying atrial wall thickness. Injury to the esophagus was quantified using the Arrhenius equation as well as by determining the percentage of tissue reaching a 50°C lethal isotherm. Atrial thickness was varied between 0.6 mm to 2.0 mm. Esophageal cooling was set to the recommended 4°C coolant temperature.

Results

Using 50 W power settings in control (non-cooled) conditions, esophageal lesion transmurality ranged from 75% to 82% as calculated by the Arrhenius equation, with decreased transmurality seen as atrial wall thickness increased. With the addition of proactive cooling, lesion transmurality decreased to less than 43% in the thinnest atrial wall sections, and to less than 25% in the thickest atrial wall sections. Using 90 W power settings, control conditions showed esophageal lesion transmurality ranging from 52% to 63%, with the greatest damage seen in the middle-range atrial thicknesses (1 and 1.5 mm). Active esophageal cooling reduced this esophageal injury to less than 12% transmurality through the esophagus in all anatomic scenarios.

Conclusions

Modeling suggests that the use of proactive esophageal cooling significantly reduces esophageal lesion transmurality under HPSD ablation conditions across a range of typical atrial wall thicknesses, including in very thin myocardium, where the risk of esophageal injury is greatest.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Attune
Atrio-ventricular nodal re-entrant tachycardia ablation step by step low fluoro approach to prevent unexpected AV block
Authors: Marchese P , Gennaro F , Mazzotta G , Grossi P
Published: October 2022

Background

Slow pathway (SP) radiofrequency (RF) ablation of AVNRT has a success rate of more than 98%, but up to 2% risk of unpredictable and frustrating AV node block despite the energy being delivered to the posterior aspect of Koch's Triangle (KT) which is far from the recorded His signal. A possible explanation is an atypical location of the AV node. KT pace-mapping (KTPM) has been demonstrated to be useful to recognize when AV is abnormally located in the mid or posteroseptal aspect of the KT. In these cases cryoablation would be the best choice because it is a well-established technique for the successful treatment of AVNRT with no complications reported but with a recurrence rate around 10% at long-term follow-up. Voltage bridge mapping (VBM) is a validated and effective technique in guiding cryoablation of AVNRT, with a complete acute success rate and no recurrences at mid-term follow-up.

Aim

To evaluate our low-fluoro step-by-step approach for AVNRT ablation including KTPM and VBM aiming to eliminate the risk of unpredictable AV node block.

Methods

The right atrium and coronary sinus electroanatomical mapping was done and diagnostic catheters were positioned at His and coronary sinus. After AVNRT diagnosis, 3D KTPM was performed. We developed it according to the “conventional” one in order to evaluate and visualize atypical AV node location during low-fluoro procedures. This was achieved by stimulating with the mapping catheter in the anteroseptal, posteroseptal and midseptal region respectively. Each point has been collected on 3D System measuring the interval between the stimulus to the His deflection (Fig. 1A–C). Voltage bridge-mapping was also performed, and both have been used as reference for SP RF ablation. If 3D KTPM showed a posterior extension of the AV node, then ablation was performed using cryo-energy aiming to reduce the risk of permanent AV node iatrogenic block.

Methods and results

71 consecutive patients (mean age 61.0±14.5 SD, 46% female) undergoing low-fluoro ablation of AVNRT by 3D mapping system. KTPM was achieved in all the patients. In the 67 (94.3%) pts who showed superoparaseptal location of the AV node RF ablation was successfully performed. In 4 (5.7%) pts with midseptal extension of the AV node (Fig. 1D) a voltage-bridge mapping guided cryo-ablation was successfully performed (Fig. 1E). The mean procedural time was 95±18 SD min. Mean fluoro time was zero. After a mean follow-up of 28.5±16.7 SD moths, neither recurrences nor complications were recorded.

Conclusion

This is the first study to show how a tailored low-fluoro AVNRT SP ablation approach including 3D-PM of KT and VBM could be helpful to eliminate the risk of unpredictable and frustrating AV block. Our preliminary results would possibly encourage larger cohort, multicenter studies.

Funding Acknowledgement

Type of funding sources: None.
Automatic left atrial segmentation from cardiac CT using computer graphics imaging and deep learning
Authors: Feng R , Deb B , Ganesan P , Rogers A J , Ruiperez-Campillo S , Clopton P , Tjong F V , Chang H J , Rodrigo M , Zaharia M , Narayan S M
Published: October 2022

Introduction

Segmenting left atrial (LA) substructures, including the LA body, appendage (LAA), and pulmonary veins (PVs), from computed tomography (CT) is central to electroanatomic mapping for ablation and functional studies in patients with atrial fibrillation (AF). However, this process requires manual outlining which needs special training, is subjective, and is difficult to scale. Computer graphics imaging (CGI) has been applied in media, film, and computer-aided design to reliably segment complex structures using their basic geometric representations.

Purpose

We hypothesized that LA substructures can be “virtually” dissected using CGI to separate geometric contours of the “convex ellipsoid” LA, “tubular” PVs, and “conical” LAA. We further hypothesized that the results of virtual dissection can be used to train a deep learning (DL) model to segment raw CT scans.

Methods

First, a mathematical method based on CGI techniques – erosion and dilation – was developed to “virtually dissect” the convex LA body from the original concave shell in publicly available digital atria with diverse simulated morphologies (Fig. 1A). The PVs and LAA were then automatically revealed and labeled by a 3D subtraction approach. Second, we refined precise LA/PV/LAA boundaries by tuning hyper-parameters from N=5 patient shells (Fig. 1B). Third, we used virtual dissection to train a DL model to segment CTs in N=20 patient atria (Fig. 1C). Finally, we applied this pipeline to segment raw CTs in a validation cohort of N=105 patients (23.8% women, 63.8±10.3Y; Fig. 1D).

Results

Virtual dissection accurately identified LA/PV/LAA boundaries in the training set (Dice coefficients 89–98%). In the independent test cohort (N=105), this automated pipeline accurately segmented raw CTs with Dice 81–95% (Fig. 1D) compared to a panel of experts (p<0.001).

Conclusion

CGI of basic cardiac geometry combined with deep learning in small datasets can accurately segment raw CT scans in large populations. This computational pipeline may automate and simplify cardiac image processing and ablation procedures, and could be applied to the ventricle or other organ systems for diverse therapeutic strategies or to train machine learning.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health
Deep vein thrombosis after leadless pacemaker implantation
Authors: Hayashi T , Shishido K S , Moriyama N M , Tobita K T , Murakami M M , Saito S S
Published: October 2022

Background

A leadless pacemaker has been used widely. The necessity of using large sheath (23 Fr) is one of the disadvantages of implanting leadless pacemaker. There are some reports about deep vein thrombosis (DVT)after leadless pacemaker, but the accurate number of DVT after leadless pacemaker implantation is unknown.

Method

This retrospective study analyzed patients who were implanted leadless pacemaker from January 2018 to August 2022. We included the patients who were conducted ultrasound for DVT both before and after leadless implantation. The primary endpoint was incidence of DVT by ultrasound one day after leadless pacemaker implantation in the leg where sheath was inserted.

Results

89 patients were included in this study. The mean age of this study was 86.2±7.4 years old and 88 patients (99%) were implanted leadless pacemaker from their right femoral vein. 49 patients (55%) took anticoagulant before leadless pacemaker implantation. About the primary endpoint, 12 patients (13.5%: 8 patients without anticoagulant and 4 patients with anticoagulant) had newly asymptomatic DVT. After the univariate analysis, patients with low body weight (OR: 0.90, CI: 0.83–0.98, p=0.011), short height (OR: 0.87, CI: 0.79–0.96, p=0.005) and small diameter of the femoral vein (OR: 0.65, CI: 0.46–0.92, p=0.015) tended to have DVT. The use of anticoagulant did not affect the incidence of DVT (OR: 0.365, CI: 0.10–1.3, p=0.114).

Conclusion

Asymptomatic DVT by ultrasound is found in 13.5% of patients after leadless pacemaker. The small body patients might have easier to have DVT after leadless pacemaker. We should consider performing ultrasound to check for DVT in high-risk patients after leadless pacemaker implantation.

Funding Acknowledgement

Type of funding sources: None.
Mortality and 30-day readmission rate following leadless pacemaker implantation: insights from the Nationwide Readmissions Database
Authors: Tonegawa-Kuji R , Kanaoka K , Mori M , Nakai M , Iwanaga Y
Published: October 2022

Background

Clinical trials and registry data showed encouraging outcomes for leadless pacemaker (LP) implantation. However, reports of patient characteristics, trends, and clinical outcomes in a real-world population are limited.

Purpose

To provide real-world evidence of the rates, trends, and patient characteristics associated with in-hospital complications and 30-days readmission after LP implantations.

Methods

Using the all-payer, nationally representative Nationwide Readmissions Database between 2017 and 2019, we analyzed leadless or conventional pacemaker implantations. The national trends of in-hospital mortality, in-hospital complication rates and 30-day readmission rates after pacemaker implantation and their national trends were analyzed. Mixed-effects multivariable logistic regression analysis was performed to identify factors associated with in-hospital death and 30-days readmission in LP patients.

Results

A total of 137,732 admissions (age: 78 [70–85], 5,986 LP implantations) were analyzed (Figure 1). The in-hospital mortality, overall in-hospital complication rate, and 30-days readmission rates after LP implantations were 5.0%, 16%, and 16%, respectively. In LP recipients, the national estimate of in-hospital mortality declined from 10.9% in the second quarter of 2017 to 4.3% in the fourth quarter of 2019 (P<0.001) (Figure 2a). Furthermore, the national estimate of overall complication rate declined from 20.6% in the second quarter of 2017 to 13.0% in the fourth quarter of 2019 (P<0.001) (Figure 2b). Conversely, non-elective 30-day readmission rate did not show any increasing or decreasing trends in LP recipients (P=0.74) (Figure 2c). In LP recipients, female sex (odds ratio [OR] 1.42, 95% confidence interval [CI] 1.04–1.93), history of heart failure (OR 2.02, 95% CI 1.46–2.79), and first quartile annual pacemaker implantation hospital volume (OR 2.49, 95% CI 1.56–3.97, fourth quartile annual pacemaker implantation hospital volume used as a reference standard) were factors associated with in-hospital death.

Conclusions

Analysis of the nationally representative claims database in the US showed in-hospital mortality, complication rates, and non-elective 30-day readmission rate of 5.0%, 16%, and 16% respectively, for LP implantation performed during hospitalization. Although in-hospital mortality and complication rates showed a decreasing trend over time, ongoing surveillance is needed for the safety of LP implantation.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Intramural research fund (21-6-9)for cardiovascular diseases of national cerebral and cardiovascular center.
3 Tesla magnetic resonance imaging in patients with cardiac electronic implantable devices: a single center experience
Authors: Nikorowitsch J , Tahir E , Erley J , Muellerleile K , Metzner A , Adam G , Blankenberg S , Kirchhof P , Toennis T , Fluschnik N
Published: October 2022

Background

Cardiac magnetic resonance imaging (MRI), a key method guiding medical diagnosis and therapy, is increasingly performed at 3 Tesla (T) field strength. Growing evidence suggests a relatively safe conductance of 1.5 T MRI in patients with cardiac implantable electronic devices (CIEDs), leading to conditional certification of some CIEDs for MRI. However, data on the safety of MRI imaging at 3 T in patients with CIEDs are scarce.

Purpose

We analysed the safety of clinically indicated 3 T MRI in patients with “3T MRI-conditional” and “3 T MRI-non-conditional” CIEDs.

Methods

We performed a retrospective single-center analysis of consecutive patients with CIEDs labelled by the manufacturer as “MRI non-conditional”, “1.5 T MRI-conditional” and “3 T MRI-conditional”. Patients underwent clinically indicated 3 T MRI of different thoracic and non-thoracic body regions from April 2020 to February 2022. Devices were interrogated and programmed appropriately before and after scanning. Statistics included median and interquartile range. Measurements of device and lead function and integrity before and after scanning were assessed. Adverse events included all-cause death, arrhythmias, loss of capture, inappropriate anti-tachycardia therapies, electrical reset and lead or generator failure during or shortly after MRI scan.

Results

One hundred twenty-eight 3 T MRI scans were performed in 94 patients (mean age 72±16 years, 36.2% female). 3T MRI scans were performed in patients with “non-MRI-conditional” devices (n=9), “1.5 T MRI-conditional” devices (n=22), and “3 T MRI-conditional” devices (n=97). Patients were pacemaker-dependent in 24 MRI scans. After MRI, lead impedance had changed by 100 Ohms or more in seven cases (4 atrial and 3 right ventricular leads). P-wave (−25%) reduction was noted in one, R-wave (−50%) reduction in two cases. Right atrial and ventricular threshold exceeded the limit of 0,5V in one case each only in “3 T MRI-conditional” devices. No clinically relevant adverse events occurred.

Conclusion

3 T MRI was safely conducted in patients with “3 T MRI-conditional” and “non-MRI conditional” CIEDs in our single-center study. Pending verification in independent series, our data suggest that clinically indicated 3T MRI scans should not be withheld from patients with cardiac pacemakers or defibrillators.

Funding Acknowledgement

Type of funding sources: None.
Subcutaneous Implantable Defibrillator programming: an analysis of Italian clinical practice and its evolution
Authors: Rordorf R , Viani S , Biffi M , Pieragnoli P , Nigro G , Migliore F , Francia P , De Filippo P , Dello Russo A , D'Onofrio A , Bisignani G , Ottaviano L , Caravati F , Valsecchi S , Vicentini A
Published: October 2022

Background

The UNTOUCHED study (designed in 2017 and published in 2021) demonstrated high success rate for termination of ventricular arrhythmias, and very low inappropriate shock rate in subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients. The prescribed device programming included a conditional zone between 200 and 250 beats per minute (bpm) with discrimination algorithms employed to avoid delivering inappropriate shocks in this range, and a shock zone based on the rate alone for arrhythmias >250 bpm. Whether these results influenced clinical practice is unknown.

Methods

We assessed the programming at implantation and changes in programmed parameters at follow-up (≥1 year) in a cohort of S-ICD recipients enrolled in the Rhythm Detect registry at 56 centers.

Results

From 2013 to 2021, 1521 consecutive patients (aged 49±15 years; 79% male, 52% dilated cardiomyopathy, 31% arrhythmic syndromes, 16% hypertrophic cardiomyopathy) were analyzed. At implantation, the programmed sensing vector was the Primary in 59% of patients, the Secondary in 35%, the Alternate in 6%. At follow-up, the sensed vector was changed in 13% of patients. The programmed conditional zone cutoff was set to 200 [200–220] bpm (median [25–75 percentile]), and the shock zone cutoff to 230 [210–250] bpm. At follow-up, the conditional zone cutoff was reprogrammed in 13% of patients, but the median value in the overall population did not change (200 [200–220] bpm; p>0.05). The shock zone cutoff was reprogrammed in 43% of cases, and the overall median value was 250 [230–250] bpm (p<0.001 versus implantation). Sorting patients by implantation date, we observed that in the first 764 patients (implanted ≤2017) the shock zone cutoff was set to 210 [210–230] bpm at implantation and to 240 [230–250] bpm at follow-up (reprogrammed in 66% of cases). While in patients implanted >2017, it was already set to 250 [230–250] bpm at implantation and to 250 [240–250] bpm at follow-up (reprogrammed in 20% of cases, p<0.001 versus ≤2017).

Conclusions

S-ICD programming parameters are rarely changed during follow-up (approximately 13% of patients). The only exception in clinical practice was the shock zone cutoff. Centers have begun to program high cutoffs in recent years. This happened at the time of implantation for new S-ICD recipients and at follow-up for pre-existing implants. This behavior is consistent with a substantial adoption of published trial findings and could contribute to reduce the incidence of inappropriate shocks in clinical practice.

Funding Acknowledgement

Type of funding sources: None.
Ventricular tachycardia ablation before an implantable cardioverter defibrillator in secondary prevention: is always the best option?
Authors: Martinho A , Almeida J , Antonio N , Elvas L , Goncalves L
Published: October 2022

Background

Among patients with an aborted episode of malignant ventricular arrhythmias without a reversible cause, the Implantable Cardioverter Defibrillator (ICD) is considered an important therapy for secondary prevention of sudden cardiac death (SCD). Some authors propose primary catheter ablation and deferred ICD implantation may be the preferred approach in patients with substrate-related ventricular tachycardia.

Purpose

We want to evaluate the need of secondary time ablation in patients with secondary prevention ICD, when submitted only a medical therapy after the index event.

Methods

We conducted a retrospective, observational study of 90 patients who consecutively implanted ICD after an aborted episode of malignant ventricular arrhythmias without a reversible/known cause between 2014 and 2020. Patients with Brugada Syndrome, Wolff-Parkinson-White syndrome, QT related diseases and previous ventricular tachycardia (VT) ablation were excluded. Baseline clinical characteristics were analyzed, and a 1-year follow-up was performed: cardiovascular (CV) death, sustain VT), ventricular fibrillation (VF), antitachycardia pacing (ATP), ICD shock, VT ablation.

Results

Mean age was 58±18 years, 80% (n=72) were male and 65.5% (n=59) had a non-ischemic etiology. Most of the patients (61%; n=56) present with hemodynamic unstable VT or syncope, and 38% (n=34) with SCD [most due to VF (n=30)]. After the index event 41.1% (n=37) and 83.8% (n=75) initiate antiarrhythmic and beta-blocker (BB), respectively. During 1-year follow-up (FUP) 11.1% (n=10) had a sustain VT and 2.2% (n=2) VF leading to ATP and appropriated shock in 11.1% (n=10) and 10% (n=9), respectively. There was 2 CV death [due to acute heart failure (HF)], 8 HF hospitalization and 3 VT ablation during follow-up. The presence of chronic kidney disease at baseline was the only parameter related to 1-year CV death (1.3% vs 18.2%, p=0.039) and HF hospitalization (0% vs 18.2%, p=0.014). The antiarrhythmic after index event was associated with a significant less sustain VT [10% vs 45%, OR 0.114 (IC 95% 0.014 to 0.927] and consequently ATP (adjusted for age) and had a numerical benefit in ICD shock (2.7% vs 15.1%, p=0.076) and need of a secondary time ablation (0% vs 5.7%, p=0.266).

Conclusion

The ICD implant with antiarrhythmic therapy, as a primary approach to secondary prevention (vs ablation), after an aborted episode of malignant ventricular arrhythmias still showed to be a secure and viable first option.

Funding Acknowledgement

Type of funding sources: None.
T-wave alternans poorly prognostic in primary prophylactic ICD patients: a prospective EU-CERT-ICD study
Authors: Pelli A , Junttila M J , Kentta T V , Schlogl S , Zabel M , Malik M , Reichlin T , Willems R , Vos M A , Harden M , Friede T , Sticherling C , Huikuri H
Published: October 2022

Background

New methods to identify patients who truly benefit from primary prophylactic implantable cardioverter defibrillation (ICD) are urgently needed. T-wave alternans (TWA) represents a beat-to-beat fluctuation in the morphology of the ST-segment and T-wave. It has been shown to associate with arrhythmogenesis of heart and sudden cardiac death [1]. We hypothised that TWA might associate with benefit from ICD implantation in primary prevention.

Methods

In EU-CERT-ICD study, we prospectively enrolled 2327 primary prophylactic ICD candidates from 15 European countries. A 24-hours Holter-monitoring was taken from all recruited patients at enrolment. TWA was assessed from Holter-monitoring using MMA method with Getemed Cardioday software. To assess the benefit from ICD treatment, we used outcomes all-cause mortality, appropriate shock and survival benefit. We conducted Cox regression model, competing risk regression model and propensity score adjusted Cox regression model. TWA was assessed both as contiguous variable and with cut-off points <47 μV and <60 μV.

Results

Final cohort included 1,734 valid T-wave alternans samples, 1,211 patients with ICD and 523 control patients with conservative treatment, with mean follow-up time 2.3 years. TWA <60 μV predicted lower all-cause mortality in ICD patients in univariate cox regression model (HR 1.484, 95% CI 1.024–2.151, p=0.0374). In multivariate models, TWA did not predict death or appropriate shocks in ICD patients. In addition, TWA did not predict death in control patients. In propensity score adjusted Cox regression model, TWA did not predict ICD benefit.

Conclusion

T-wave alternans is poorly prognostic in primary prophylactic ICD patients. Altough it may predict life-threatening arrhythmias and sudden cardiac death in several patient populations, it cannot be used in assessing benefit from implantable cardioverter defibrillator in primary prevention among patients with ejection fraction ≤35%.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Community's 7th Framework Program FP7/2007-2013
Intracardiac echocardiographically guided permanent pacemaker implantation is a feasible imaging tool with comparable procedural efficacy and safety
Authors: Shin S Y , Jung M , Byeon K , Kang K
Published: October 2022

Background

Amongst cardiovascular interventions, pacemaker implantation procedure is one of the most hazardous in terms of radiation exposure due to its proximity and unprotected radiation exposure. In order to reduce radiation hazards, alternative imaging tool to guide pacemaker implantation should be sought. The aim of this study is to investigate the feasibility, efficacy, and safety of intracardiac echocardiographically (ICE) guided pacemaker implantation.

Methods

We retrospectively investigated pacemaker implantation with ICE guidance. ICE catheter was placed in right atrium (RA). Right ventricular (RV) lead was placed in RV apex within home view (low RA, 2-4 O'clock). Then RA lead was placed in RA appendage within mid RA 1-2 O'clock view. Fluoroscopy was used only for verifying lead redundancy (2 or 3 second duration before pocket closure). Other procedure steps were similarly performed as in conventional fluoroscopic method. Radiation dosage, patient safety, total procedure time, and lead parameters were assessed and compared.

Results

From June 2013 to March 2021, a total of 270 patients underwent pacemaker implantation either with ICE or with fluoroscopy. Amongst them, ICE guided implantation was attempted in 35 patients. In order to exclude potential bias caused by the operator's learning curve, we excluded early 5 cases out of ICE group. Radiation exposure was markedly decreased within ICE group (2.3±4.4 Gy cm2 in ICE group vs. 27.2±50.5 Gy cm2 in fluoroscopy group, P<0.001). The total procedure time and complication rate showed no significant difference between groups. In ICE group, atrial lead parameters were better than those of fluoroscopy group (impedance 454±57 Ω vs. 533±125 Ω, P<0.001).

Conclusion

In 30 patients with ICE guided pacemaker implantation, radiation exposure was markedly decreased without any trade-offs in terms of patients' safety and procedural success. Furthermore, operation team members' physical stress reduction also might be potentially guaranteed.

Funding Acknowledgement

Type of funding sources: None.