Characterization of high-density mapping in catheter ablation for persistent atrial fibrillation: results from the Advisor™ HD Grid Mapping Catheter Observational study.

BACKGROUND: We quantified and characterized the outcomes of ablation in persistent atrial fibrillation (PersAF) subjects, and the utility of electroanatomical mapping with a market-released high-density (HD) mapping catheter. METHODS: PersAF subjects received electroanatomical mapping with the Advisor™ HD Grid mapping catheter, Sensor Enabled™ (HD Grid) and radiofrequency (RF) ablation to gather data regarding ablation strategies, mapping efficiency, quality, and outcomes. Subjects were enrolled from January 2019 to April 2020 across 25 international sites and followed for 12 months after the procedure. RESULTS: Three hundred thirty-four PersAF subjects (average age 64.2 years; 76% male; 25.4% previous AF ablation) were enrolled. Multiple map types were generated in a variety of rhythms using HD Grid. Significant differences in low voltage areas were identified in maps generated with the HD Wave Solution™ electrode configuration when compared to the standard configuration, which in some cases, influenced physicians' ablation strategies. PV-only ablation strategy was used in 59.0% of subjects and 34.1% of subjects received PV ablation and additional lesions. Of the subjects, 82.0% were free from recurrent atrial arrhythmias at 12 months and new or increased dose of class I/III antiarrhythmic drugs. About 6.0% of subjects experienced a serious adverse event or serious adverse device effect through 12 months including 1 event deemed related to HD Grid and the index procedure by the investigator and 1 death unrelated to study devices. CONCLUSIONS: The results of this study (NCT03733392) support the safety and utility of electroanatomical mapping with HD Grid in subjects with complex arrhythmias, such as PersAF in the real-world setting.

Safety, feasibility, and prognostic value of stress perfusion CMR in patients with MR-conditional pacemaker.

AIMS: To assess the safety, feasibility, and prognostic value of stress cardiovascular magnetic resonance (CMR) in patients with pacemaker (PM). METHODS AND RESULTS: Between 2008 and 2021, we conducted a bi-centre longitudinal study with all consecutive patients with MR-conditional PM referred for vasodilator stress CMR at 1.5 T in the Institut Cardiovasculaire Paris Sud and Lariboisiere University Hospital. They were followed for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death or non-fatal myocardial infarction. Cox regression analyses were performed to determine the prognostic value of CMR parameters. The quality of CMR was rated by two observers blinded to clinical details. Of 304 patients who completed the CMR protocol, 273 patients (70% male, mean age 71 ± 9 years) completed the follow-up (median [interquartile range], 7.1 [5.4-7.5] years). Among those, 32 experienced a MACE (11.7%). Stress CMR was well tolerated with no significant change in lead thresholds or pacing parameters. Overall, the image quality was rated good or excellent in 84.9% of segments. Ischaemia and late gadolinium enhancement (LGE) were significantly associated with the occurrence of MACE (hazard ratio, HR: 11.71 [95% CI: 4.60-28.2]; and HR: 5.62 [95% CI: 2.02-16.21], both P < 0.001). After adjustment for traditional risk factors, ischaemia and LGE were independent predictors of MACE (HR: 5.08 [95% CI: 2.58-14.0]; and HR: 2.28 [95% CI: 2.05-3.76]; both P < 0.001). CONCLUSION: Stress CMR is safe, feasible and has a good discriminative prognostic value in consecutive patients with PM.

Prospective evolution of cardiac arrhythmia care: 2030 vision.

Cardiovascular diseases, which are the leading global cause of death, should increase by 40% by 2030, reaching close to 24 million deaths worldwide. Atrial fibrillation is the most common heart rhythm disorder, ahead of conduction disturbances and ventricular arrhythmias. Studies estimate that 7.6 million people aged>65 years in the European Union had atrial fibrillation in 2016, and this figure is predicted to increase by 89% to 14.4 million by 2060. Recent innovations in cardiac arrhythmia care, such as cardiac device miniaturization and smart devices, might revolutionize the future of patient care. Yet, the level of adoption of these breakthroughs will depend on their acceptability by patients and healthcare professionals, and on the pace of transformation of the French healthcare system (encouraged by "Ma Santé 2022"). In this article, we detail the major trends that could impact patients with heart rhythm disorders and their healthcare professionals by 2030. Eight major trends and their associated effects on patient care and healthcare professionals' practices were discussed: technical evolution of cardiac devices; digitalization of the healthcare system, and telecardiology; the rise of smart devices; the rise of "big data" and artificial intelligence; patient empowerment; evolution of healthcare; healthcare transformation with "Ma Santé 2022"; and new funding models. These "multidimensional" changes give us room in this study to outline two scenarios for the evolution of care of patients with heart rhythm disorders in the near future.

Position paper concerning the competence, performance and environment required for the practice of ablation in children and in congenital heart disease.

The population of patients with congenital heart disease (CHD) is continuously increasing, and a significant proportion of these patients will experience arrhythmias because of the underlying congenital heart defect itself or as a consequence of interventional or surgical treatment. Arrhythmias are a leading cause of mortality, morbidity and impaired quality of life in adults with CHD. Arrhythmias may also occur in children with or without CHD. In light of the unique issues, challenges and considerations involved in managing arrhythmias in this growing, ageing and heterogeneous patient population and in children, it appears both timely and essential to critically appraise and synthesize optimal treatment strategies. The introduction of catheter ablation techniques has greatly improved the treatment of cardiac arrhythmias. However, catheter ablation in adults or children with CHD and in children without CHD is more technically demanding, potentially causing various complications, and thus requires a high level of expertise to maximize success rates and minimize complication rates. As French recommendations regarding required technical competence and equipment are lacking in this situation, the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Affiliate Group of Paediatric and Adult Congenital Cardiology have decided to produce a common position paper compiled from expert opinions from cardiac electrophysiology and paediatric cardiology. The paper details the features of an interventional cardiac electrophysiology centre that are required for ablation procedures in adults with CHD and in children, the importance of being able to diagnose, monitor and manage complications associated with ablations in these patients and the supplemental hospital-based resources required, such as anaesthesia, surgical back-up, intensive care, haemodynamic assistance and imaging. Lastly, the need for quality evaluations and French registries of ablations in these populations is discussed. The purpose of this consensus statement is therefore to define optimal conditions for the delivery of invasive care regarding ablation of arrhythmias in adults with CHD and in children, and to provide expert and - when possible - evidence-based recommendations on best practice for catheter-based ablation procedures in these specific populations.

Preventing the risk of coronary injury in posteroseptal accessory pathway ablation in children: different strategies and advantages of fluoroscopy integrated 3D-mapping system (CARTO-UNIVU™).

PURPOSE: To evaluate various strategies in order to minimize the risk of coronary injury during posteroseptal accessory pathways ablation in children. METHODS: We retrospectively reviewed 68 posteroseptal accessory pathways ablation procedures (20 decremental and 48 typical accessory pathways) performed in 62 pediatric patients at our institution between July 2009 and December 2016. Only posteroseptal accessory pathways targeted near or within the coronary sinus were included and ablation was mostly performed using irrigated tip radiofrequency. RESULTS: Median patient age was 11 years with a median body weight of 39 kg. Thirty patients underwent a coronary angiogram, 21 were coupled to the 3D navigation system CARTO-UNIVU™. The coronary angiogram showed a distance of less than 5 mm between the coronary artery and the ablation site in 40% of our cases; 3 patients had a coronary injury related to RF ablation, 6 patients were switched for cryoablation, 3 patients received limited RF energy (20 W). There were no demographic data predicting the proximity of the coronary artery to the ablation site. CONCLUSION: Ablation of posteroseptal accessory pathways specifically in children carries a risk of coronary artery injury which is probably underestimated. The use of merged 3D images and coronary angiograms, the reduction of RF energy or the switch to cryoablation are possible alternatives to limit the risk of coronary injury.

Active or passive pulmonary vein in atrial fibrillation: is pulmonary vein isolation always essential?

BACKGROUND: The role of pulmonary veins (PVs) in persistent atrial fibrillation (AF) perpetuation appears less important than in paroxysmal AF. Electrogram-based substrate ablation is not widely performed as a stand-alone strategy. OBJECTIVE: To evaluate PV activity in AF perpetuation and efficacy of our patient-tailored ablation strategy (electrogram-based substrate ablation with or without pulmonary vein isolation [PVI]). METHODS: One hundred twenty-one patients with paroxysmal (n = 19; 15.7%), persistent (n = 77; 63.6%), or long-standing persistent (n = 25; 20.7%) AF underwent electrogram-based substrate ablation with AF termination end point: sinus rhythm or atrial tachycardia conversion. Before ablation, we classified PVs as "passive" if silent PV or if PV cycle length is greater than left atrial appendage cycle length. No PVI was performed in such cases. RESULTS: Passive PVs were observed in 52 of 121 patients (paroxysmal AF = 0%, persistent AF = 40%, and long-standing persistent AF = 76%; P < .0001]). Substrate ablation terminated AF in 95.6% (sinus rhythm conversion in 80.2%). Compared with patients with active PVs, patients with passive PVs had longer AF sustained duration (19.1 ± 29.7 months vs 4.9 ± 11.1 months; P < .0001), larger left atrial diameter (46.9 ± 7.3 mm vs 41.9 ± 6.0 mm; P = .0014), lower left ventricular ejection fraction (45.4% ± 13.5% vs 55.1% ± 9.4%; P < .0001), and more often structural heart disease (57% vs 33%; P = .02). After a follow-up of 20.39 ± 11.23 months (1.6 procedures per patient), 82% were arrhythmia free with this strategy. CONCLUSIONS: PV activity during AF decreases with AF chronicity, left atrial dilatation, and left ventricular ejection fraction. Our patient-tailored ablation strategy without systematic PVI provides good results.

Automated Detection of Complex Fractionated Atrial Electrograms In Substrate-Based Atrial Fibrillation Ablation: Better Discrimination with a New Setting of CARTO® Algorithm.

Background and purpose: Up until recently complex fractionated atrial electrogram (CFAE) ablation has been considered as time consuming and its achievement as challenging, especially for non experimented operators. Moreover, results of substrate ablation based on CFAE detection in atrial fibrillation (AF) are very disparate, mainly because of the operator's subjective electrogram visual analysis and the difficult distinction between CFAEs really involved in AF perpetuation from other CFAE. Automatic detection provided by 3D mapping system (CARTO® algorithm) can be helpful but is not selective enough, drawing too wide CFAE areas. We sought to demonstrate a better selectivity of a new CFAE algorithm setting in order to better discriminate CFAEs really involved in AF perpetuation from other CFAE. Methods and subjects: A population of 32 patients (60.4±12.7 years) with paroxysmal (n=3) AF (PAF), persistent (n=16) AF (PeAF) or long-standing persistent (n=13) AF (LSPeAF), and AF history =56±65 months, underwent CFAE ablation based on visual analysis. Before ablation, left atrium CFAE mapping was performed on CARTO® shortest complex interval (SCI) algorithm and reanalyzed after ablation with the two different settings: nominal (SCI 60-120ms/0.05-0.15mV) vs. customized setting (SCI 30-40ms/0,04-0.15mV). CFAE areas automatically detected by both settings (CFAE-CARTO® areas) were respectively measured. The decision to ablate CFAE was only based upon the operator's electrogram visual analysis taken as reference because of high AF termination rate (93.7%) due to operator's CFAE selection experience. These ablation points drawn reference-CFAE areas involved in AF perpetuation (ablation point=60mm2) allowing to compare the selectivity of the two previous automatic maps. Results: With the customized CARTO® SCI setting, we observed a significant reduction of CFAE areas detected by CARTO® (CFAE-CARTO® areas) and of the ablated CFAE surface inside non-CFAE CARTO® areas, (30.6±20.5cm2 vs. 68.8±24.5cm2, p<0.0001, and 1.86±1.82% vs. 3±3%, p=0.003). Furthermore the proportion of ablated areas/detected CFAE-CARTO® areas were higher with customized setting (38.2±19.6% vs. 20.4±17.5%, p=0.008). Conclusions: This new customized CFAE algorithm setting is significantly more selective than the nominal one and allows an automated detection of CFAE really involved in AF perpetuation truer to an efficient experienced operator's electrogram visual analysis.

Correlation between AF substrate ablation difficulty and left atrial fibrosis quantified by delayed-enhancement cardiac magnetic resonance.

BACKGROUND: Studies have shown that the presence of left atrial (LA) fibrosis can be assessed by LA delayed-enhancement cardiac magnetic resonance (LA DE-CMR) and may be predictive of outcome after ablation for atrial fibrillation (AF). We sought to test the hypothesis that the amount of LA fibrosis evaluated by DE-CMR correlates with the difficulty of complex fractionated atrial electrograms (CFAE) ablation. METHODS: Twenty-two consecutive patients (86.4% nonparoxysmal AF) underwent substrate CFAE radiofrequency (RF) ablation (±Pulmonary veins isolation) with AF termination as the endpoint. LA DE-CMR was performed prior to ablation. A global index of DE was defined by an average of six LA segmental scores based on a four-grade scale (no enhancement to maximum enhancement). Time between first RF application and AF termination, and RF duration until AF termination, was recorded. CFAE area/total LA surface was also measured on CARTO maps (Biosense Webster, Diamond Bar, CA, USA). These measures served to evaluate ablation difficulty, and were correlated with CMR images by double-blinded analysis. RESULTS: Ablation restored sinus rhythm in 20 of 22 patients (91%), with a time to terminate AF of 140 ± 91 minutes. There was a significant correlation between the global averaged DE-CMR fibrosis grade and the electrophysiological substrate indexes such as "time to terminate AF" (Rho = 0.70, P = 0.0003), "RF duration until AF termination" (Rho = 0.65, P = 0.001), and a trend toward correlation with "CFAE area/LA surface" (Rho = 0.47, P = 0.03). CONCLUSIONS: LA DE-CMR can predict increased difficulty of CFAE ablation in AF. This tool may be beneficial in both selection of patients and ablation strategy.

A case for ambidextrous doctors.

We report the case of a 30-year-old man with situs inversus totalis, recurrent orthodromic reciprocal tachycardia, and the Wolff-Parkinson-White syndrome. He underwent, in our department, radiofrequency ablation of an accessory pathway (AP) located in the lateral mitral atrioventricular ring. Ablation of the AP was carried out successfully through a patent foramen ovale under fluoroscopic guidance, in a right anterior oblique projection with a 30° tilt and in anteroposterior views. We also used a mirror reversal of electrocardiogram (ECG) leads to better judge the site of the AP by using existing ECG algorithms. Complete situs inversus is a rare disorder, which has no consequence for the patient in the absence of cardiac or extracardiac involvement. Ablation of APs in situs inversus has been previously reported in only three cases of complete situs inversus and one case of situs ambiguous. In patients with mirror-image dextrocardia, APs seem more often located on the 'left' free wall (mitral annulus), as in the normal population. Radiofrequency ablation is feasible and safe after mirror reversion of the ECG electrodes and fluoroscopy.

Percutaneous epicardial radiofrequency ablation of ventricular arrhythmias after failure of endocardial approach: a 9-year experience.

INTRODUCTION: Management of recurrent ventricular tachycardia (VT) remains difficult. Neither medical treatments nor conventional endocardial radiofrequency (RF) ablation are efficient to prevent some recurrences. In these cases, a percutaneous pericardial approach may be required. METHODS: Among all the patients referred to our center between 1998 and 2007 for a VT ablation, 276 endocardial and 35 epicardial procedures were performed, the latter in case of failure of the conventional approach. We report in this study the efficacy and the safety of these 35 interventions analyzed retrospectively. RESULTS: Thirty-five epicardial procedures were attempted in 32 patients. An electric storm was present in 5 of 32 (16%) patients, with other individuals presenting with a recurrent VT despite drug therapy and a previous endocardial ablation. Pericardial space was reached in 28 of 32 patients by a xyphoidian puncture. An immediate success of RF on clinical VT was obtained in 22 of 29 (76%) cases. During a mean follow-up of 384 +/- 405 days, only 9 patients (26%) experienced a recurrence of a sustained VT. One patient died from tamponade during the procedure despite surgical drainage. Other complications had no significant consequences. CONCLUSION: Percutaneous epicardial puncture is feasible and relatively safe in patients with recurrent VT in whom conventional endocardial RF ablation failed. Epicardial RF ablation offers a high success rate in these challenging patients with only few severe complications.

Three-dimensional electroanatomical mapping of right periatriotomy tachycardias after interatrial defect correction.

BACKGROUND: Pericicatricial right intra-atrial reentrant tachycardias occur frequently in patients who have undergone surgical correction of an interatrial defect. AIM: To characterize the tachycardia circuits using three-dimensional electroanatomical mapping. METHODS: Twelve tachycardias were analysed in 11 patients who had undergone surgical correction of an interatrial defect. Patients were divided into two groups: atrial flutter with typical sawtooth flutter waves in inferior leads, atrial tachycardia with clearly delimited P waves separated by an isoelectric line. RESULTS: Seven tachycardias were classified as atrial flutter; three-dimensional mapping identified a peritricuspid circuit with inferior vena cava-tricuspid annulus isthmus involvement in all cases. All atrial flutters were terminated by linear ablation of this isthmus. Five tachycardias were classified as atrial tachycardia; three-dimensional mapping identified periatriotomy loops. All atrial tachycardias were ablated successfully between two scars or between a scar and an anatomical barrier. CONCLUSION: Periatriotomy loops were always associated with an atrial tachycardia electrocardiogram pattern. Three-dimensional electroanatomical mapping appeared to be particularly useful for circuit identification and for ablation of these complex arrhythmias.

Effects of inadvertent atrioventricular block on clinical outcomes during cryoablation of the slow pathway in the treatment of atrioventricular nodal re-entrant tachycardia.

AIMS: The study aimed at evaluating the long-term effects of transient atrioventricular (AV) block on clinical outcomes during atrioventricular nodal re-entrant tachycardia (AVNRT) cryoablation. METHODS AND RESULTS: In 150 consecutive patients (39 +/- 14 years, ineffective anti-arrhythmic drugs 1.9 +/- 1.3), slow-pathway cryoablation for AVNRT was performed. A 7 Fr 6 mm-tip cryocatheter was used. After successful cryomapping (-30 degrees C), defined as jump abolition or AV nodal refractory period prolongation, cryoablation (-80 degrees C for 4 min) was applied if no AV block occurred. Atrioventricular nodal re-entrant tachycardia inducibility was checked after 30 min. Acute success (AVNRT non-inducibility) was achieved in 142 patients (95%). Overall, after a follow-up of 18 +/- 10 months, 118 of 150 patients (79%) were recurrence-free (including 2 patients for whom the procedure was unsuccessful). Among successful procedures, 116 of 142 (82%) patients were recurrence-free. During cryoablation, inadvertent transient AV block of varying degrees occurred in 34 patients (22.7%), namely, increased PR in 17 patients and a 2nd-3rd AV block in the remaining 17. In 24 patients, AV block occurred at the last effective site (increased PR in 13 patients and a 2nd-3rd AV block in 11). In the study population as a whole, univariate predictors of recurrence in the follow-up were AVNRT inducibility (P < 0.001), increased PR at the last effective site (P < 0.001), residual jump (P < 0.02), and small Koch's triangle (X-ray distance < 11 mm between the His and coronary sinus ostium catheters; P < 0.02). Atrioventricular nodal re-entrant tachycardia inducibility (P < 0.03), increased PR (P < 0.01), and small Koch's triangle (P< 0.04) were independently significant. For attempts at the last effective site, 3 groups of patients were compared: 13 patients with increased PR duration (Group A), 11 with a 2nd-3rd AV block (Group B), and 126 without AV block (Group C). Cryo-application time was 277 +/- 203 s in Group A, 75 +/- 87 s in Group B, and 253 +/- 135 s in Group C (A vs. B, P < 0.01; B vs. C, P < 0.001; and C vs. A, P= NS). There was no statistical difference among groups in the atriogram/ventriculogram amplitude ratio at the site of the last attempt, unsuccessful acute procedure, small Koch's triangle, and residual jump. Actuarial incidence of recurrence-free status at 12 months was 38% in A, 82% in B, and 82% in C (A vs. B, P < 0.05; B vs. C, P = NS; and C vs. A, P < 0.001). CONCLUSION: All AV blocks occurring during cryoablation were transient, confirming the safety of this method. An increased PR duration at the last effective site is associated with a higher recurrence rate, whereas a 2nd-3rd degree AV block has a recurrence rate similar to that of patients without AV block despite a shorter cryo-application time at the last site.

Brugada syndrome in pure black Africans.

AIMS: Although all races are concerned with the Brugada syndrome, no case has ever been reported among black Africans. We describe five different cases in this specific group of populations. METHODS AND RESULTS: In all patients, Brugada syndrome was identified after detailed noninvasive and invasive evaluations. Sex ratio was four males for one female. Convulsive syncope was noticed in 1 patient with a family history of sudden death. Diagnostic coved-type pattern was observed spontaneously in the normal position of right precordial leads in 3 patients and in a higher position of leads in 3 patients. Sixty percent had first-degree atrioventricular block. An ajmaline test was performed in 4 patients and was positive either in normal position of leads or in superior position in all of them. Sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) was inducible during programmed ventricular stimulation in 3 patients. Right ventricular cineangiography found localized apical hypokinesia with preserved systolic function in 1 patient. Automatic cardioverter defibrillator was implanted in 2 patients. SCN5A was not found in any of the patients. CONCLUSION: These observations demonstrate that Brugada syndrome is also present in black African populations, and increasingly reported cases of apparent sudden death in the sub-Saharan part of the world need to rule out cardiac electrical disturbance such as Brugada syndrome.

[Brugada syndrome unmasked by lithium treatment]. / Un syndrome de Brugada majoré par un traitement au lithium.

INTRODUCTION: The Brugada syndrome is a rare genetic disease that can lead to death. Its diagnosis requires electrocardiography. CASE: A 36-year-old man was admitted with syncope. Brugada syndrome was diagnosed by the typical ECG pattern. The interaction between lithium therapy and ECG was shown clearly by the alternating type 1 and type 3 Brugada ECG patterns, depending on lithium status. DISCUSSION: The Brugada syndrome may be unmasked by lithium therapy, due to its properties as a Na+ channel blocker, even at low doses. This case also demonstrated the usefulness of ECG in detecting the Brugada syndrome before and during lithium prescription.

Interaction of chelerythrine with inositol phosphate metabolism.

Chelerythrine, a potent inhibitor of protein kinase C (PKC), was evaluated for its effect on inositol phosphate (IP) metabolism in newborn rat cardiomyocytes in culture. In a first step, we evaluated the effect of chelerythrine on IP accumulation in basal conditions. For a 10(-4) M dose, 5-phosphatase activity (which dephosphorylates IP3 into IP2) was completely blocked and we observed a large increase in IP accumulation limited to IP2 without any increase in IP3, strongly suggesting that chelerythrine at this dose modifies IP metabolism. At a lower dose (10(-5) M) of chelerythrine, which did not modify IP accumulation and 5-phosphatase activity in basal conditions, the response to angiotensin II stimulation was completely abolished by the addition of chelerythrine. We conclude thus that chelerythrine, even at 10(-5) M, interacts markedly with IP metabolism, and caution should be exerted when interpreting the results obtained with this drug, which is still currently used at this dose.