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The relations between endocardial voltage mapping and the genetic background of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) have not been investigated so far. A total of 97 patients with proved or suspected ARVC who underwent 3-dimensional endocardial mapping and genetic testing have been retrospectively included. Presence, localization, and size of scar areas were correlated to ARVC diagnosis and the presence of a pathogenic variant. A total of 78 patients (80%) presented with some bipolar or unipolar scar on endocardial voltage mapping, whereas 43 carried pathogenic variants (44%). Significant associations were observed between presence of endocardial scars on voltage mapping and previous or inducible ventricular tachycardia, right ventricular function and dimensions, or electrocardiogram features of ARVC. A total of 60 of the 78 patients (77%) with an endocardial scar fulfilled the criteria for a definitive arrhythmogenic right ventricular dysplasia diagnosis versus 8 of 19 patients (42%) without scar (p = 0.003). Patients with a definitive diagnosis of ARVC had more scars from any location and the scars were larger in patients with ARVC. In the 68 patients with a definitive diagnosis of ARVC, the presence of any endocardial scar was similar whether an ARVC-causal mutation was present or not. Only scar extent was significantly greater in patients with pathogenic variants. There was no difference in the presence and characteristics of scars in PKP2 mutated versus other mutated patients. The 3-dimensional endocardial mapping could have an important role for refining ARVC diagnosis and may be able to detect minor forms with otherwise insufficient criteria for diagnosis. The trend for larger scar extent were observed in mutated patients, without any difference according to the mutated genes.

In repaired tetralogy of Fallot (TOF), little is known about characteristics of patients with rapid ventricular tachycardia (VT). Also, whether patients with a first episode of nonrapid VT may subsequently develop rapid VT or ventricular fibrillation (VF) has not been addressed.The objectives of this study were to compare patients with rapid VT/VF with those with nonrapid VT and to assess the evolution of VT cycle lengths (VTCLs) overtime.Data were analyzed from a nationwide registry including all patients with TOF and implantable cardioverter-defibrillator (ICD) since 2000. Patients with ≥1 VT episode with VTCL ≤250 ms (240 beats/min) formed the rapid VT/VF group.Of 144 patients (mean age 42.0 ± 12.7 years; 104 [72%] men), 61 (42%) had at least 1 VT/VF episode, including 28 patients with rapid VT/VF (46%), during a median follow-up of 6.3 years (interquartile range 2.2-10.3 years). Compared with patients in the nonrapid VT group, those in the rapid VT/VF group were significantly younger at ICD implantation (35.2 ± 12.6 years vs 41.5 ± 11.2 years; P = .04), had more frequently a history of cardiac arrest (8 [29%] vs 2 [6%]; P = .02), less frequently a history of atrial arrhythmia (11 [42%] vs 22 [69%]; P = .004), and higher right ventricular ejection fraction (43.3% ± 10.3% vs 36.6% ± 11.2%; P = .04). The median VTCL of VT/VF episodes was 325 ms (interquartile range 235-429 ms). None of the patients with a first documented nonrapid VT episode had rapid VT/VF during follow-up.Patients with TOF and rapid VT/VF had distinct clinical characteristics. The relatively low variation of VTCL over time suggests a room for catheter ablation without a backup ICD in selected patients with well-tolerated VT.Clinicaltrials.gov identifier: NCT03837574.

Prediction of ventricular arrhythmias (VA) mostly relies on left ventricular ejection fraction (LVEF), but with limited performance. New echocardiographic parameters such as mechanical dispersion have emerged, but acoustic window sometimes precludes this measurement. Nuclear imaging may be an alternative. We aimed to assess the ability of mechanical dispersion, measured with phase standard deviation (PSD) on radionuclide angiocardiography (RNA), to predict VAs.This retrospective monocentric observational study included all patients who underwent a tomographic RNA from 2015 to 2019. Phase analysis yielded PSD and follow-up was examined to identify VAs, heart transplantation, and death.The study population consisted of 937 patients, mainly with LVEF ≤ 35% (425, 45%). Most had ischemic (334, 36%) or dilated cardiomyopathies (245, 26%). We identified 86 (9%) VAs. PSD was strongly associated with the occurrence of VA [hazard ratio per 10 ms increase (HRThe occurrence of ventricular arrhythmias was predicted by mechanical dispersion assessed by RNA, even after adjustment for LVEF and GLS.

Leadless pacing has emerged as an alternative to conventional transvenous pacemakers to mitigate the risks of pocket- and lead-related complications but its use remains controversial in young adults mostly because experience in this patient population is limited. We sought to examine the feasibility and safety of implanting leadless single chamber pacemakers in young adults.This multicenter, retrospective, observational study sought to evaluate the safety, efficacy, and electrical performance of the Micra VR Transcatheter Pacemaker System (Medtronic) in patients between 18 and 40 years who underwent implantation of a leadless pacemaker for any indication at the university medical centers of Bordeaux, Clermont-Ferrand, Toulouse, and Tours (France), between 2015 and 2021. The primary safety endpoint was freedom from system-related or procedure-related major complications at 6 months. The primary efficacy endpoint was the combination of a low (≤2 V) and stable (increase within 1.5 V) pacing capture threshold at 6 months.Leadless pacemaker implantation was successful in all 35 patients. At six months, safety endpoint was met for 35 (100%) and efficacy endpoint for 34 (97%) patients. During a follow-up of 26±15 months (range: 6-60 months), Safety endpoint remained 100% and efficacy endpoint was 94%. Leadless pacemaker retrieval was not required in any patient. Approximately one third of patients (n=13, 37%) had40% ventricular pacing burdens at one year, including all 10 patients with a complete AV block but also 3 patients with normal AV conduction during implantation. One patient reported symptoms of pacemaker syndrome which was confirmed using Holter recording and successfully treated using reprogramming.In this observational study, leadless pacemakers demonstrated favorable short- and intermediate-term safety and effectiveness in young adults. This article is protected by copyright. All rights reserved.

Aims FRench Attitude reGistry in case of ICD LEad replacement (FRAGILE) registry was set-up to describe the attitude in different French institutions in case of implantable cardioverter-defibrillator (ICD) lead replacement, extraction, or abandonment and to compare outcomes in both groups. Methods and results Prospective observational study comparing two attitudes in case of ICD lead replacement, extraction, or abandonment. Primary endpoint describes the attitude in different French centres, collect parameters that may influence the decision. Secondary endpoint compares early and mid-term (2 years) complications in both groups. Between April 2013 and April 2017, 552 patients were included in 32 centres. 434 (78.6%) were male, mean patient’s age was 60.3 ± 14.4 years. In 56.9% of the cases, the decision was to explant the lead. Patients in the extraction group were younger than in the abandonment group (56.7 ± 14.5 vs. 65 ± 12.7 P Conclusion In this registry, the strategy in case of non-infected ICD lead replacement was mainly influenced by patient’s age and comorbidities and lead dwelling time. No difference was observed in outcomes in both strategies.

Background: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Methods: A Nationwide French Registry including all patients with tetralogy of Fallot with an ICD was initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event end point was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Results: A total of 165 patients (mean age, 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (interquartile range) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least 1 appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively; P =0.03). Overall, 71 (43.0%) patients presented with at least 1 ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) patients in primary prevention, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with, respectively, 0, 1, 2, or ≥3 guidelines-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (hazard ratio, 3.47 [95% CI, 1.19–10.11]), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 ( P =0.006). Patients with congestive heart failure or reduced left ventricular ejection fraction had a higher risk of nonarrhythmic death or heart transplantation (hazard ratio, 11.01 [95% CI, 2.96–40.95]). Conclusions: Patients with tetralogy of Fallot and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03837574.

International audience; Background: Women with congenital heart disease at high risk for sudden cardiac death have been poorly studied thus far.Objectives: The aim of this study was to assess sex-related differences in patients with tetralogy of Fallot (TOF) and implantable cardioverter-defibrillators (ICDs).Methods: Data were analyzed from the DAI-T4F (French National Registry of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator) cohort study, which has prospectively enrolled all patients with TOF with ICDs in France since 2010. Clinical events were centrally adjudicated by a blinded committee.Results: A total of 165 patients (mean age 42.2 ± 13.3 years) were enrolled from 40 centers, including 49 women (29.7%). Among the 9,692 patients with TOF recorded in the national database, the proportion of women with ICDs was estimated to be 1.1% (95% CI: 0.8%-1.5%) vs 2.2% (95% CI: 1.8%-2.6%) in men (P < 0.001). The clinical profiles of patients at implantation, including the number of risk factors for ventricular arrhythmias, were similar between women and men. During a median follow-up period of 6.8 years (IQR: 2.5-11.4 years), 78 patients (47.3%) received at least 1 appropriate ICD therapy, without significant difference in annual incidences between women (12.1%) and men (9.9%) (HR: 1.22; 95% CI: 0.76-1.97; P = 0.40). The risk for overall ICD-related complications was similar in women and men (HR: 1.33; 95% CI: 0.81-2.19; P = 0.30), with 24 women (49.0%) experiencing at least 1 complication.Conclusions: Our findings suggest that women with TOF at high risk for sudden cardiac death have similar benefit/risk balance from ICD therapy compared with men. Whether ICD therapy is equally offered to at-risk women vs men warrants further evaluation in TOF as well as in other congenital heart disease populations. (French National Registry of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator [DAI-T4F]; NCT03837574)

Background Anticoagulation during catheter ablation should be closely monitored with activated clotting time (ACT). However vitamin K antagonists (VKA) or direct oral anticoagulant drugs (DOAC) may act differently on ACT and on heparin needs. The aim of this study was to compare ACT and heparin requirements during catheter ablation under various oral anticoagulant drugs and in controls. Methods Sixty consecutive patients referred for ablation were retrospectively included: group I (n = 15, VKA), group 2 (n = 15, uninterrupted rivaroxaban), group 3 (n = 15, uninterrupted apixaban), and group 4 (n = 15, controls). Heparin requirements and ACT were compared throughout the procedure. Results Heparin requirements during the procedure were significantly lower in patients under VKA compared to DOAC, but similar between DOAC patients and controls. Activated clotting time values were significantly higher in patients under VKA compared to DOAC and similar in DOAC patients versus controls. Furthermore, anticoagulation control as evaluated by the number/proportion of ACT> 300 as well as the time passed over 300 seconds was significantly better in patients under VKA versus DOAC, without significant differences between DOAC and controls. Finally, the number of patients/ACT with excessive ACT values was significantly higher in VKA versus DOAC patients versus controls. There was no significant difference between rivaroxaban and apixaban for ACT or heparin dosing throughout the procedure. Conclusion Vitamin K antagonists allowed less heparin requirement despite reaching higher ACT values and more efficient anticoagulation control (with more excessive values) compared to patients under DOAC therapy and to controls. There was no difference in heparin requirements or ACT between DOAC patients and controls., VKA allowed less heparin requirement despite reaching higher ACT values and more efficient anticoagulation control (although with a higher risk for excessive values) compared to patients under long‐term direct anticoagulant therapy and to controls referred for ablation Activated clotting time may not be a sensitive marker of anticoagulation in patients under direct anticoagulant drugs and heparin

Background Hybrid ablation for the treatment of atrial fibrillation is a single combined procedure consisting in a minimally thoracoscopic surgical ablation followed by a catheter ablation. This promising technique is recommended in persistent atrial fibrillation according to the current guidelines but is not routinely performed in France, mainly due to the absence of reimbursement by the French National Health Insurance. Aims The aim of this prospective and single-centre study was to analyse, for the first time in France, the feasibility, efficacy and complication rates of hybrid ablation in patients with persistent atrial fibrillation. Methods Hybrid ablation was performed in 15 consecutive patients (13 men, mean age 61 ± 6 years) with persistent (7 patients) or long standing persistent (8 patients) atrial fibrillation. Results Hybrid ablation was completed in 14/15 patients. Eleven patients returned in sinus rhythm during the procedure. Two patients (13%) had major per-procedural complications and 2 had minor complications. During an average follow-up of 25 ± 6 months, 6 patients (40%) underwent a redo catheter ablation because of atrial tachycardia, mainly peri-mitral atrial flutter. At 1 year follow up, 14/15 patients were in sinus rhythm, including 11 free of antiarrhythmic drugs.

Background Previous results from global Micra Transcatheter Pacemaker clinical trials have demonstrated leadless pacing as a safe and attractive option for patients with prior cardiac implantable electronic device (CIED) infection and extraction. Whether outcomes differ based upon the timing of prior device extraction has not been studied. Purpose To describe characteristics and outcomes of patients undergoing CIED extraction during or prior to Micra implantation. Methods Patients who underwent CIED explant and Micra implantation were identified from the Micra Post-Approval Registry and Micra Acute Performance studies. Baseline characteristics were summarized. A Fine-Gray competing risk model was used to compare risk for major complication through 24 months. Results Of the 2739 patients included in the studies, 99 (3.6%) patients had CIED extraction the day of Micra implantation (same day) and 127 (4.6%) patients had CIED extraction within 30 days prior to Micra implantation (prior). Although infection was the primary reason for CIED extraction in both groups, a larger proportion of prior patients underwent extraction for this reason (87.4% vs. 42.4%). In contrast, more same day patients underwent CIED extraction for physician/elective reasons (16.2% vs. 3.1%). Same day patients prior device history included pacemaker (42 dual chamber and 30 single chamber), ICD (1 single chamber and 4 dual chamber), CRT (7 CRT-ICD and 13 CRT-P) while prior patients device history included pacemaker (29 single chamber, 80 dual chamber), ICD (3 dual chamber), CRT (5 CRT-ICD and 7 CRT-P). Overall, patients with extraction were aged 72.8±14.3 years, predominantly male (65.9%), and medical history was similar between groups, with the exception to CHF, which was higher for the same day group (18.2% vs 6.3%, P=0.021). The implant success rate was 98.0% for same day patients and 100% for prior patients. Median procedure duration was not significantly different between the groups (26.0 minutes and 25.0 minutes for same day and prior, respectively). Average follow-up duration was 16.5±13.8 months (range 0–53.4) for same day patients and 18.2±15.2 months (range 0–58.3) for subsequent patients. The rate of acute major complications ( Conclusion The Micra leadless pacemaker was implanted with a high success rate following CIED extraction. Outcomes following CIED extraction appear similar, whether the extraction is performed during or prior to Micra implant. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Medtronic, Inc. Risk of major complications

Background and objectives Severe forms of Tachycardia-induced cardiomyopathy (TIC) with cardiogenic shock are not well described so far, and efficiency of catheter ablation in this setting is unknown. Methods We retrospectively included consecutive patients admitted to the Intensive Cardiac Care Unit for acute heart failure with cardiogenic shock associated with atrial arrhythmia and managed by ablation. Result Fourteen patients were included, each with cardiogenic shock and two needing the use of extracorporeal membrane oxygenation. Successful ablation was performed in the acute setting or over the following weeks. Two patients experienced relapses of arrhythmias and were treated by new ablation procedures. At 7.5 ± 5 months follow-up, all patient were alive with stable sinus rhythm. The left ventricular Ejection Fraction dramatically improved (21 vs. 54%, p = 0.001) as well as the end-diastolic left ventricular diameter (61 vs. 51 mm, p = 0.01) and NYHA class (class IV in all vs. median 1, p = 0.002). Conclusion Restoration and maintenance of sinus rhythm in severe TIC with cardiogenic shock and atrial arrhythmias lead to a major increase or normalization of LVEF, reduction of ventricular dimensions, and improvement in functional status. Ablation is efficient in long-term maintenance of sinus rhythm and may be proposed early in refractory cases.

Catheter ablation (CA) in children using fluoroscopy carries risks inherent to ionizing radiation exposure.The objective of this study was to demonstrate the feasibility of using low frames rate during ablation in children to maximally decrease radiation dose.Hundred sixty eight successive patients18 years of age undergoing CA performed under a 3.75 frames/second rate were retrospectively included. Demographics, procedural and dosimetry data were analysed. The effective dose (ED) was evaluated in a subgroup of 14 patients.Median age and weight were 15 years and 54kg, 72% had WPW, 10% AV node reentrant tachycardia, 10% ventricular tachycardia (atrial tachycardia, flutter and atrial fibrillation for the other cases). Acute success was achieved in 98.5% without any complication. Median procedure and fluoroscopy duration were 120 and 16minutes. Median Dose Area Product (DAP) and Air Kerma were 2.46Gy.cmLow frame rate fluoroscopy is a highly effective and safe approach in decreasing radiation exposure during CA in children without altering the success rate of the procedure. ED is low, similar to natural/leisure irradiation. This approach can be considered a good alternative to 3D-based procedures in terms of efficiency and radiation issues, at least for WPW ablations.

Left ventricular assist device (LVAD) implantation has become an important therapeutic option in patients with end-stage heart failure, with many of them already having an implantable cardioverter-defibrillator (ICD) at the time of LVAD surgery. LVAD electromagnetic interference (EMI) with loss

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): INSERM - French Society of Cardiology OnBehalf DAIT4F Investigators Background Sudden cardiac death is a major cause of death in tetralogy of Fallot (TOF) and right ventricular overload is commonly considered as a potential trigger for ventricular arrhythmias. Purpose We aimed to assess the impact of pulmonary valve replacement (PVR) on ventricular arrhythmias burden using a population of TOF patients with continuous cardiac monitoring by implantable cardioverter defibrillator (ICD). Methods Nationwide French registry including all TOF patients with an ICD. Survival data with recurrent events were used to compare the burden of appropriate ICD therapies before and after PVR in patients who underwent PVR over the study period. Results A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% males) were included from 40 centers. Over a median (IQR) follow-up period of 6.8 (2.5-11.4) years, 26 (15.8%) patients underwent PVR. Among those patients, 18 (69.2%) experienced at least one appropriate ICD therapy. When considering all ICD therapies delivered before (n = 62) and after (n = 16) PVR, the burden of ICD appropriate therapies was significantly lower after PVR (HR 0.21, 95%CI 0.08-0.56, p = 0.002). In the overall cohort, PVR before ICD implantation was also independently associated with a lower risk of appropriate ICD therapy in primary prevention patients (HR 0.29, 95%CI 0.10-0.89, p = 0.031). Conclusions In this cohort of high-risk TOF patients implanted with an ICD, the burden of appropriate ICD therapies was significantly reduced after PVR. While optimal indications and timing for PVR are debated, these findings suggest the importance of considering ventricular arrhythmias in the overall making-decision process. Abstract Figure.

International audience; Objectives: This study aimed to assess the impact of pulmonary valve replacement (PVR) on ventricular arrhythmias burden in a population of tetralogy of Fallot (TOF) patients with continuous cardiac monitoring by implantable cardioverter-defibrillators (ICDs).Background: Sudden cardiac death is a major cause of death in TOF, and right ventricular overload is commonly considered to be a potential trigger for ventricular arrhythmias.Methods: Data were analyzed from a nationwide French ongoing study (DAI-T4F) including all TOF patients with an ICD since 2000. Survival data with recurrent events were used to compare the burden of appropriate ICD therapies before and after PVR in patients who underwent PVR over the study period.Results: A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% male) were included from 40 centers. Over a median follow-up period of 6.8 (interquartile range: 2.5 to 11.4) years, 26 patients (15.8%) underwent PVR. Among those patients, 18 (69.2%) experienced at least 1 appropriate ICD therapy. When considering all ICD therapies delivered before (n = 62) and after (n = 16) PVR, the burden of appropriate ICD therapies was significantly lower after PVR (HR: 0.21; 95% confidence interval [CI]: 0.08 to 0.56; p = 0.002). Respective appropriate ICD therapies rates per 100 person-years were 44.0 (95% CI: 35.7 to 52.5) before and 13.2 (95% CI: 7.7 to 20.5) after PVR (p < 0.001). In the overall cohort, PVR before ICD implantation was also independently associated with a lower risk of appropriate ICD therapy in primary prevention patients (HR: 0.29 [95% CI: 0.10 to 0.89]; p = 0.031).Conclusions: In this cohort of high-risk TOF patients implanted with an ICD, the burden of appropriate ICD therapies was significantly reduced after PVR. While optimal indications and timing for PVR are debated, these findings suggest the importance of considering ventricular arrhythmias in the overall decision-making process. (French National Registry of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator [DAI-T4F]; NCT03837574).

Introduction Several noninvasive risk factors for ventricular arrhythmias have been described in postmyocardial infarction (MI) patients, whose relationships with scar characteristics and modifications by ablation are unknown. Methods Twenty-two patients with previous MI referred for ventricular tachycardia ablation were prospectively included. ECG, heart rate variability (HRV), signal-averaged ECG (SA-ECG), and T wave alternans (TWA) were performed before and after radiofrequency ablation. Scar areas were correlated to preablation parameters. Pre and postablation parameters were furthermore compared. Results Left ventricular ejection fraction and some spectral and time-domain HRV parameters were significantly correlated to the scar areas. QRS duration was larger after vs before ablation (120 ± 29 vs 105 ± 22 msec, P = .01). No significant modification in time or spectral domain of HRV was observed. There was no significant change in TWA and SA-ECG before and after ablation. Borderline decreases in quantitative TWA parameters were noted in patients with positive TWA and successful ablation procedure. Conclusion Some noninvasive risk factors were linked to the scar areas, but few were significantly modified after ablation. Larger populations are needed to demonstrate significant differences or correlations.

Objectives This study sought to identify atrial tachycardia (AT) demonstrating atrial activation duration (AAD) lasting longer than the length of the tachycardia cycle (TCL); to assess AT prevalence; and to evaluate the mechanisms and characteristics associated with these AT episodes by using the Rhythmia system (Boston Scientific, Marlborough, Massachusetts). Background Ultra-high-density mapping allows very accurate characterization of mechanisms involved in AT. Some complex patterns may involve AAD which is longer than the tachycardia cycle length (TCL) which makes maps difficult to interpret. Prevalence and characteristics of such ATs are unknown. Methods A cohort of 100 consecutive patients undergoing ablation of 125 right (n = 21) or left (n = 104) ATs using ultra-high-density mapping were retrospectively included. Offline calculation of right or left AAD was compared to TCL. Results Mean TCL was 293 ± 65 ms, and mean AAD was 291 ± 74 ms (p = NS). AT mechanisms were macro-re-entry in 74 cases (59%), localized re-entry in 27 cases (22%), and focal AT in 21 cases (17%) (types were mixed in 3 cases). Fifteen ATs (12%) had AADs that were longer than the TCL (71 ± 45 ms longer, from 10 to 150 ms). TCL was equal to the AAD in 97 ATs (78%), whereas 13 ATs (10%) had AAD shorter than the TCL (focal AT in each case). There were no differences between right and left atria for prevalence of ATs with AADs that were longer than the TCLs. There were significant differences in AT mechanisms according to the AAD-to-TCL ratio (p Conclusions ATs with AAD lasting longer than the TCL were present in approximately 10% of the ATs referred for ablation, mostly in ATs caused by localized re-entry. Ultra-high-density mapping allows detection of these complex patterns of activation.

Ultra-high-density mapping allows very accurate characterization of circuits/mechanisms in atrial tachycardia (AT). Whether these advantages will translate into a better procedural or long-term clinical outcome is unknown. Sixty consecutive AT ablation procedures using ultra-high-density mapping (Rhythmia™, group 1) were retrospectively compared to 60 consecutive procedures using standard high-density mapping (Carto/NavX™, group 2) (total 209 AT, 79% left AT). A higher number of maps were performed in group 1 (4.8 ± 2.5 vs 3.2 ± 1.7, p = 0.0001) with similar acquisition duration (12 ± 5 vs 13 ± 6 min per map, p = ns), although with a greater number of activation points (10,543 ± 5854 vs 689 ± 1827 per map, p

BACKGROUND The arrhythmic burden after discharge in patients with new-onset left bundle branch block (LBBB) undergoing transcatheter aortic valve replacement (TAVR) with the balloon-expandable SAPIEN 3 (S3) valve remains largely unknown. OBJECTIVE The purpose of this study was to determine the incidence of late arrhythmias in patients with new-onset LBBB undergoing TAVR with the balloon-expandable S3 valve. METHODS This was a multicenter, prospective study that included 104 consecutive TAVR patients with new-onset persistent LBBB following TAVR with the S3 valve. An implantable cardiac monitor (Reveal XT, Reveal LINQ) was implanted before discharge. The primary endpoint was the incidence of high-degree atrioventricular block or complete heart block (HAVB/CHB). RESULTS A total of 40 patients (38.5%) had at least 1 significant arrhythmic event, leading to a treatment change in 17 (42.5%). Significant bradyarrhythmias occurred in 20 of 104 patients (19.2%) (34 HAVB/CHB episodes, 252 severe bradycardia episodes), with 10 of 20 patients (50%) exhibiting at least 1 episode of HAVB/ CHB. Most HAVB/CHB episodes ( 60%) occurred within 4 weeks after discharge. Nine patients ( 8.7%) underwent permanent pacemaker implantation at 12 months based on the Reveal findings (6 HAVB/CHB, 3 severe bradycardia). CONCLUSION S3 valve recipients with new-onset LBBB have a high arrhythmic burden, with more than one-third of patients exhibiting at least 1 significant arrhythmic episode within 12 months (HAVB/ CHB in 10% of patients). About one-half of bradyarrhythmic events occurred within 4 weeks after discharge. These results should inform future strategies on the use of continuous electrocardiographic monitoring in TAVR S3 patients with new conduction disturbances following the procedure.

BACKGROUND: The utility of ultra-high definition mapping (UHDM) for ablation of premature ventricular contractions (PVC) remains undetermined. The aim of this study was to investigate UHDM for PVC ablation, and additionally to compare to conventional technique. METHODS: Twenty patients investigated using UHDM were prospectively included and analyzed. Electrophysiological caracteristics and results were compared to 40 patients ablated using fluoroscopy only. RESULTS: 2541±2033 EGMs and 331±240 PVC beats were recorded for each patient. Surfaces of isochronal activations were 2.3±1.7 and 6.9±6.1 cm(2) (first 10 and 20 ms). Local scar was present in 40% and local block in 65%. Areas of pace-mapping > 95, 90 and 85% concordance were 1.5±3.4, 2.1±3.9 and 3.3±5 cm(2). Mean distance between the ablation site and the site of best pace-mapping or of earliest activation was 8±8 mm and 5±7 mm. Pre-potential was noted in 17% vs 26% controls (ns). QS pattern was present in 83% vs 83% controls (ns), and earliest activation was - 31±50 vs - 25±14 ms in controls (ns). Procedure (100±36 vs 190±51 min, p< 0.0001) and fluoroscopy duration (15±9 vs 24±9 min, p=0.005) were shorter in controls. Acute success was achieved in 65% patients with UHDM and in 72% controls (p=ns) with lower residual PVC burden in the control group. Over a follow-up of 19±12 months, long-term success was similar between groups (65 vs 68%). CONCLUSIONS: UHDM may reveal poorly recognized activation features and PVC mechanism. In this series, conventional mapping was quicker and did clinically as well as UHDM.

Introduction Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Objective We aimed to describe long-term follow-up of TOF patients implanted with ICD through a nationwide French registry. Methods Nationwide French Registry including all TOF patients with an ICD initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event endpoint was the time from ICD implantation to first appropriate ICD therapy. Clinical events were centrally adjudicated by a blinded committee. Results A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (IQR) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least one appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively, P = 0.03). Overall, 71 (43.0%) patients presented with at least one ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) primary prevention patients, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with respectively no, one, two, or ≥ three guideline-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (HR 3.47, 95% CI 1.19–10.11), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 (P = 0.006) ( Fig. 1 ). Conclusions Patients with TOF and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification.

Background Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Purpose We aimed to describe long-term follow-up of patients with TOF and ICD through a large nationwide registry. Methods Nationwide Registry including all TOF patients with an ICD initiated in 2010. The primary outcome was the first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Cox proportional hazard models were used to identify predictors of appropriate ICD therapies and ICD-related complications. Results A total of 165 patients (mean age 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (IQR) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least one appropriate ICD therapy, giving an annual incidence of 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively, p=0.03). Overall, 71 (43.0%) patients presented with at least one complication, including inappropriate ICD shocks in 42 (25.5%) patients and lead/generator dysfunction in 36 (21.8%) patients. Among 61 (37.0%) primary prevention patients, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with respectively no, one, two, or ≥ three guideline-recommended risk factors. In our cohort, QRS fragmentation was the only independent predictor of appropriate ICD therapies (HR 4.34, 95% CI 1.42–13.23), and its integration in a model with current criteria increased the area under the curve from 0.61 to 0.72 (p=0.006). No patient with left ventricular ejection fraction (LVEF) ≤35% without at least one other risk factor had appropriate ICD therapy. Patients with congestive heart failure and/or reduced LVEF had a higher risk of non-sudden death or heart transplantation (HR=11.01, 95% CI: 2.96–40.95). Conclusions Our findings demonstrate high rates of appropriate therapies in TOF patients with an ICD, including in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria might improve risk stratification beyond low LVEF. Freedom from appropriate ICD therapy Funding Acknowledgement Type of funding source: None

Background: Studies of ventricular fibrillation (VF) in humans are limited because of the short available duration. We sought to study surface ECG waveforms and effect of ablation in long-lasting VF in patients with left assist devices. Methods: Continuous 12-lead ECG of 5 episodes of long-lasting VF occurring in 3 patients with left ventricular assist device were analyzed. Spectral analysis (dominant frequency) and quantification of waveform amplitude, regularity (Unbiased Regularity Index), and complexity (Nondipolar Index) were performed over a median of 24 minutes of VF. Radiofrequency ablation was performed during VF in 2 patients. Results: There was a significant increase in dominant frequency between VF onset and termination but none of the other parameters significantly changed. Some VF parameters varied from patient to patient and from lead to lead. Dominant frequency decreased after radiofrequency ablation in both cases and VF terminated spontaneously shortly after ablation in one case. The previously incessant VFs in these 2 patients did not recur afterward. Conclusions: VF rate increases over time in patients with left ventricular assist devices and is lowered by ablation. Long-lasting VF may be modified or even terminated by ablation.

Background Implantable cardioverter-defibrillator (ICD) lead dysfunction has been reported after left ventricular assist device (LVAD) implantation in limited single-center studies. We aimed at describing and characterizing the incidence of ICD lead parameters dysfunction after LVAD implantation. Methods Among the 652 patients enrolled in the ASSIST-ICD study, only patients with an ICD prior to LVAD were included (n = 401). ICD lead parameters dysfunction following LVAD implantation is defined as follows: (a) >50% decrease in sensing threshold, (b) pacing lead impedance increase/decrease by >100Ω, and (c) >50% increase in pacing threshold. Results One hundred twenty-two patients with an ICD prior to LVAD had available ICD interrogation reports prior and after LVAD. A total of 67 (55%) patients exhibited at least one significant lead dysfunction: 17 (15%) exhibited >50% decrease in right ventricular (RV) sensing, 51 (42%) had >100 Ω increase/decrease in RV pacing impedance, and 24 (20%) experienced >50% increase in RV pacing threshold. A total of 52 patients experienced ventricular arrhythmia during follow-up and all were successfully detected and treated by the device. All lead dysfunction could be managed conservatively. Conclusion More than 50% of LVAD-recipients may experience >1 significant change in lead parameters but none had severe clinical consequences.

Contains fulltext : 220908.pdf (Publisher’s version ) (Closed access) BACKGROUND: Morphology algorithms are currently recommended as a standalone discriminator in single-chamber implantable cardioverter defibrillators (ICDs). However, these proprietary algorithms differ in both design and nominal programming. OBJECTIVE: To compare three different algorithms with nominal versus advanced programming in their ability to discriminate between ventricular (VT) and supraventricular tachycardia (SVT). METHODS: In nine European centers, VT and SVTs were collected from Abbott, Boston Scientific, and Medtronic dual- and triple-chamber ICDs via their respective remote monitoring portals. Percentage morphology matches were recorded for selected episodes which were classified as VT or SVT by means of atrioventricular comparison. The sensitivity and related specificity of each manufacturer discriminator was determined at various values of template match percentage from receiving operating characteristics (ROC) curve analysis. RESULTS: A total of 534 episodes were retained for the analysis. In ROC analyses, Abbott Far Field MD (area under the curve [AUC]: 0.91; P < .001) and Boston Scientific RhythmID (AUC: 0.95; P < .001) show higher AUC than Medtronic Wavelet (AUC: 0.81; P < .001) when tested for their ability to discriminate VT from SVT. At nominal % match threshold all devices provided high sensitivity in VT identification, (91%, 100%, and 90%, respectively, for Abbott, Boston Scientific, and Medtronic) but contrasted specificities in SVT discrimination (85%, 41%, and 62%, respectively). Abbott and Medtronic's nominal thresholds were similar to the optimal thresholds. Optimization of the % match threshold improved the Boston Scientific specificity to 79% without compromising the sensitivity. CONCLUSION: Proprietary morphology discriminators show important differences in their ability to discriminate SVT. How much this impact the overall discrimination process remains to be investigated.

The introduction of a new technology always raises questions about its place compared with the reference technology. The use of an implantable cardioverter defibrillator to prevent sudden cardiac death is now a widely proven technique, with a clear statement of its indication in the guidelines. More recently, a subcutaneous implantable cardioverter defibrillator has been introduced, and appears to be an attractive technique as it removes the need to implant a lead inside the right ventricle to treat the patient, which should dramatically decrease the risk of complications over time. Currently, only one model of subcutaneous implantable cardioverter defibrillator is available on the market; its indications are the same as for transvenous implantable cardioverter defibrillators, except for patients who need stimulation because of conduction disorders or ventricular tachycardias that can potentially be treated effectively by antitachycardia pacing. The different technical characteristics of transvenous versus subcutaneous implantable cardioverter defibrillators therefore raise the question of which to choose in different clinical settings. The experts who participated in the preparation of this manuscript had three meetings, organized by the company Boston Scientific. Each expert prepared the draft of a section corresponding to a clinical situation. The choice between transvenous versus subcutaneous implantable cardioverter defibrillator was then voted on by all the experts. The results of the votes are presented in this manuscript, as it seemed important to us to show the disparities of opinion that can exist in certain situations. The votes were cast independently and anonymously.

Scars and abnormal electrograms may significantly differ according to the activation wavefront. We propose a new fast technique for reliable comparison between sinus rhythm and ventricular pacing using a single map acquisition and the Rhythmia™ 3D mapping system. A special programming of the external stimulator was assuring full stable regular paced-beat bigeminy during spontaneous rhythm. A first map was acquired for the spontaneous cardiac beat. Then the window of detection was moved to the following paced beat, and a second map was available after recalculation by the system, depicting activation and voltage of the paced cardiac beat at the same locations, with an exactly the same number of beats in both maps. Thirty patients with structural heart disease referred for ablation of ventricular tachycardia underwent this protocol, who were compared with 19 similar patients undergoing repeated maps. Duration of the mapping was significantly shorter compared to controls (34 ± 12 vs 57 ± 14 min, p

Background Brugada syndrome (BrS) is sometimes diagnosed because of chest pain. Prevalence and characteristics of such BrS patients are unknown. Methods A total of 200 BrS probands were retrospectively included. BrS diagnosis made because of chest pain (n = 34, 17%) was compared to the other ones. Results BrS probands with diagnosis because of chest pain had significantly more often smoker habits, increased body mass index, and familial history of coronary artery disease but less frequently previous resuscitated sudden death/syncope or atrial fibrillation. Presence of coronary spasm and familial coronary artery disease were independently associated with BrS diagnosed because of chest pain. They presented more often with spontaneous type 1 ST elevation (59% vs 26%, P = .0004) and higher ST elevation during the episode of chest pain compared to other patients or compared to baseline electrocardiogram after chest pain resumption. ST elevation during chest pain was lower compared to ajmaline test. A total of 20% of them had significant coronary artery disease and four (11%) had coronary spasm, and they experienced more often recurrent chest pain episodes (24% vs 5%, P = .0002). Presence of chest pain at BrS diagnosis was not correlated to future arrhythmic events in univariate analysis. Only previous sudden cardiac death (SD)/syncope and familial SD were still significantly associated with outcome in multivariate analysis. Conclusion Chest pain is a common cause for BrS diagnosis, although major part is not apparently explained by ischemic heart disease. Mechanisms leading to chest main remain unknown in the other ones. ST elevation is higher in this situation but does not seem to carry poor prognosis.

Aims Remote monitoring (RM) is considered as a standard of care for pacemaker recipients. Remote monitoring systems provide calendar-based intracardiac electrogram recordings (IEGM) only with the current pacemaker settings (passive IEGM). PREMS (Pacemaker Remote Electrogram Monitoring Study), an observational, multicentre trial, prospectively evaluated the clinical value of an active IEGM (aIEGM), including three 10-s sections (passive IEGM, encouraged sensing, and encouraged pacing), compared to other RM data and to its passive IEGM section. Secondary objectives included the added value of the aIEGM to fully assess the sensing and pacing functions of each lead. Methods and results Patients were enrolled within 3 months after pacemaker implantation and followed until the first transmitted aIEGM, which was analysed together with all other RM data. In total, 567 patients were enrolled (79 ± 9 years, 62% men, 19% single-chamber, and 81% dual-chamber pacemakers). Of 547 aIEGMs transmitted in 547 patients, 161 [29.4%; 95% confidence interval (95% CI) 25.6–33.3%] indicated at least one anomaly non-detectable with certainty—or at all—on other RM data, including atrial arrhythmia, extrasystoles, undersensing, oversensing, and loss of capture. In 21.7% of cases the detected events deserved a corrective action. The sensing and pacing function of each lead could be fully assessed in 77.3% of aIEGM (95% CI 72.6–82.0%) vs. 15.5% (95% CI 11.4–19.6%) when considering only the passive IEGM section (P

Investigation and catheter ablation of cardiac arrhythmias are currently still based on optimal knowledge of arrhythmia mechanisms in relation to the cardiac anatomy involved, in order to target their crucial components. Currently, most complex arrhythmias are investigated using three-dimensional electroanatomical navigation systems, because these are felt to optimally integrate both the anatomical and electrophysiological features of a given arrhythmia in a given patient. In this article, we review the technical background of available three-dimensional electroanatomical navigation systems, and their potential use in complex ablations.

Background Cardiac resynchronization therapy (CRT) is an effective treatment of heart failure (HF), but is limited by a substantial proportion of nonresponders. We hypothesized that adding a second left ventricular (LV) lead to deliver a triple-site CRT (V3 CRT) may improve clinical status of CRT nonresponders. Objective We assessed the feasibility and safety of adding a second LV lead to CRT nonresponders and its clinical impact. Methods Eighty-four recipients of a CRT system and considered as nonresponders as per clinical composite score (CCS) were enrolled in this multicenter study. They were randomized to the V3 arm (implantation of an additional LV lead; n=43) or control arm (no change; n = 41). Implant success rate, incidence of severe adverse events, CCS, and secondary clinical and echocardiographic end points were evaluated at 12 and 24 months. Results Positioning of a second LV lead was successful at first (40 of 44 - 90.9%) or second (4 of 44 - 9.09%) attempt. The perioperative complication rate (infection, system explant, pneumothorax, and hematoma) was high (procedures or system-related complications for 9 patients- 20.4%). After 24 months, 35 systems (79.5%) were working properly. The multinomial logistic regression model showed that V3 treatment had no significant influence (P = .27) on the CCS, number of HF hospitalizations, time to first HF hospitalization, New York Heart Association class, and LV ejection fraction at 12 and 24 months. Conclusion Although addition of a second LV lead in CRT nonresponders is feasible with a high success rate, this approach is associated with a significant rate of severe adverse events and does not provide significant long-term clinical benefits (ClinicalTrials.gov Identifier No. NCT01059175).