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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.

Background: Recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI) are mainly due to pulmonary vein reconnection. However, a growing number of patients have AF recurrences despite durable PVI. The optimal ablative strategy for these patients is unknown. We analyzed the impact of current ablation strategies in a large multicenter study. Methods: Patients undergoing a redo ablation for AF and presenting durable PVI were included. The freedom from atrial arrhythmia after pulmonary vein-based, linear-based, electrogram-based, and trigger-based ablation strategies were compared. Results: Between 2010 and 2020, 367 patients (67% men, 63±10 years, 44% paroxysmal) underwent a redo ablation for AF recurrences despite durable PVI at 39 centers. After durable PVI was confirmed, linear-based ablation was performed in 219 (60%) patients, electrogram-based ablation in 168 (45%) patients, trigger-based ablation in 101 (27%) patients, and pulmonary vein-based ablation in 56 (15%) patients. Seven patients (2%) did not undergo any additional ablation during the redo procedure. After 22±19 months of follow-up, 122 (33%) and 159 (43%) patients had a recurrence of atrial arrhythmia at 12 and 24 months, respectively. No significant difference in arrhythmia-free survival was observed between the different ablation strategies. Left atrial dilatation was the only independent factor associated with arrhythmia-free survival (HR, 1.59 [95% CI, 1.13–2.23]; P =0.006). Conclusions: In patients with recurrent AF despite durable PVI, no ablation strategy used alone or in combination during the redo procedure appears to be superior in improving arrhythmia-free survival. Left atrial size is a significant predictor of ablation outcome in this population.

Cardiac events recorders have been developed in order to record the heart rhythm during symptoms such as palpitations or presyncope, to first make a diagnosis, and subsequently drive the treatment strategy. In other circumstances, they can be also used in asymptomatic patients (to record silent atrial fibrillation for instance). Because they are non-invasive, potentially cost-saving and relatively easy to use, the external rhythm recording devices have shown some great advances in the last years, spreading from photoplethysmographic technique to real ECG reconstruction. Technological advances in the field of microelectronics, as well as in the field of data transmission have contributed to their widespread use in cardiology. The trend for miniaturization was also expanded to the implantable recorders. This paper will review will review advantages and limitations of the different existing available well-established recording devices, as well as the last technological developments in terms of ECG recordings.

Aims Outcomes in pulmonary hypertension (PH) are related to right ventricular (RV) function and remodelling. We hypothesized that changes in RV function and especially area strain (AS) could provide incremental prognostic information compared to the use of baseline data only. We therefore aimed to assess RV function changes between baseline and 6-month follow-up and evaluate their prognostic value for PH patients using 3D echocardiography. Methods and results Ninety-five PH patients underwent a prospective longitudinal study including ESC/ERS guidelines prognostic assessment and 3D RV echocardiographic imaging at baseline and 6-month follow-up. Semi-automatic software tracked the RV along the cycle, and its output was post-processed to extract 3D deformation patterns. Over a median follow-up of 24.8 (22.1–25.7) months, 21 patients died from PH or were transplanted. Improvements in RV global AS were associated with stable or improving clinical condition as well as survival free from transplant (P < 0.001). The 3D deformation patterns confirmed that the most significant regional changes occurred within the septum. RV global AS change over 6-month by +3.5% identifies patients with a 3.7-fold increased risk of death or transplant. On multivariate COX analysis, changes in WHO class, BNP, and RV global AS were independent predictors of outcomes. Besides, the combination of these three parameters was of special interest to identify high-risk patients [HR 11.5 (1.55–86.06)]. Conclusion Changes in RV function and especially changes in 3D RV AS are of prognostic importance. Our study underlines that assessing such changes from baseline to follow-up is of additional prognostic value for PH patients. Clinical Trial Registration http://clinicaltrials.gov/ct2/show/NCT02799979

Background Radiofrequency (RF) ablation of slow pathway (SP) is usually performed in sinus rhythm while monitoring the occurrence of a slow junctional rhythm (JR). JR although sensitive, is not specific for elimination of SP conduction. Our objective was to prospectively evaluate feasibility and safety of SP elimination using fast atrial rate pacing (FAP) during RF delivery. Methods Consecutive patients admitted for atrioventricular nodal re-rentrant tachycardia (AVNRT) ablation were included. The rate of proximal coronary sinus (CS) pacing was set to a value constantly yielding antegrade SP conduction, while carefully monitoring the AH interval. RF delivery (at the lower part of Koch's triangle) was considered successful if the AH shortened ≥ 14 ms or if transition from Wenckebach (WK) periods to a 1:1 conduction occurred. Results 24 patients were included (54 ± 20 y). Typical AVNRT was induced in all (cycle length 349 ± 83 ms). RF delivery during CS pacing (335 ± 73 ms) led to AH shortening by 51 ± 25 ms in 13 patients. In 10 patients, a transition from 3:2 or 4:3 WK periods to 1:1 conduction occurred during the successful pulse. In one patient, atrial fibrillation was systematically induced during FAP, requiring conventional ablation. Non-inducibility, and SP conduction disappearance was obtained in all patients. No patient developed AV block. After a follow-up of 12 ± 3 months, no recurrences were observed. Conclusion SP ablation using FAP during RF delivery allows direct visualisation of its disappearance. In our cohort of patients, this technique was feasible without safety compromise.

Background. Fibrillatory Wave Amplitude (FWA) has been described as a non-invasive marker of atrial fibrillation (AF) complexity, and it predicts catheter ablation outcome. However, the actual determinants of FWA remain incompletely understood. Objective. To assess the respective implications of anatomical atrial substrate and AF spectral characteristics for FWA. Methods. Persistent AF patients undergoing radiofrequency catheter ablation were included. FWA was measured on 1-min ECG by TQ concatenation in Lead I, V1, V2, and V5 at baseline and immediately before AF termination. FWA evolution during ablation was compared to that of AF dominant frequency (DF) measured by Independent Component Analysis on 12-lead ECG. FWA was compared to the extent of endocardial low-voltage areas (LVA I < 10%; II 10–20%; III 20–30%; IV > 30%), to the surface of healthy left atrial tissue, and to P-wave amplitude in sinus rhythm. The predictive value of FWA for AF recurrence during follow-up was assessed. Results. We included 29 patients. FWA remained stable along ablation procedure with comparable values at baseline and before AF termination (Lead I p = 0.54; V1 p = 0.858; V2 p = 0.215; V5 p = 0.14), whereas DF significantly decreased (5.67 ± 0.68 vs. 4.95 ± 0.58 Hz, p < 0.001). FWA was higher in LVA-I than in LVA-II, -III, and -IV in Lead I and V5 (p = 0.02 and p = 0.01). FWA in V5 was strongly correlated with the surface of healthy left atrial tissue (R = 0.786; p < 0.001). FWA showed moderate to strong correlation to P-wave amplitude in all leads. Finally, FWA did not predict AF recurrence after a follow-up of 23.3 ± 9.8 months. Conclusions. These findings suggest that FWA is unrelated to AF complexity but is mainly determined by the amount of viable atrial myocytes. Therefore, FWA should only be referred as a marker of atrial tissue pathology.

Resume Contexte Le bloc atrio-ventriculaire complet (BAV3) peut etre une situation urgente potentiellement letale. Notre objectif etait de decrire la gestion quotidienne des BAV3 en France, en insistant notamment sur les aspects organisationnels. Methodes De septembre 2019 a November 2019, une enquete nationale prospective (comprenant 28 questions) a ete envoyee par voie electronique a 100 medecins (Google Form). Resultats Les reponses ont ete recueillies aupres de 93 cardiologues (taux de reponse 93 %). L’implantation stimulateur cardiaque permanent pendant la nuit ou le week-end (apres 20 heures) est possible pour 49 % des operateurs ( 5 fois par an), impossible pour 36 % des operateurs. En cas de BAV3 ne repondant pas a l’isoproterenol survenant la nuit, une sonde d’entrainement electro-systolique (SEES) est implantee par : le personnel medical de garde sur place (27 %), le cardiologue interventionnel d’astreinte (21 %), le rythmologue d’astreinte (19 %), un stimulateur cardiaque permanent est implante par le rythmologue (12 %), la strategie n’est pas standardisee (15 %). 80 (86 %) cardiologues interroges ont deja observe un deplacement de SEES, une perforation cardiaque a deja ete observee par 57 (61 %), un hematome inguinal chez 35 (38 %), et cette technique a ete interdite pour 4 % des operateurs. Une sonde a fixation active (SFA) exteriorisee pour BAV3 a deja ete implantee par 50 % des operateurs. Conclusion Notre enquete montre d’importantes disparites en termes de prise en charge des BAV3 parmi les differents centres. Une SFA avec batterie de recuperation a deja ete utilisee par la moitie des centres.

Background Electrical cardioversion is the first-line rhythm control therapy for symptomatic persistent atrial fibrillation (AF). Contemporary use of biphasic shock waveforms and anterior-posterior positioning of defibrillation electrodes have improved cardioversion efficacy; however, it remains unsuccessful in >10% of patients. Objective The purpose of this study was to assess the efficacy of applying active compression on defibrillation electrodes during AF cardioversion. Methods We performed a bicenter randomized study including patients referred for persistent AF cardioversion. Elective external cardioversion was performed by a standardized step-up protocol with increasing biphasic shock energy (50–100–150–200 J). Patients were randomly assigned to standard anterior-posterior defibrillation or to defibrillation with active compression applied over the anterior electrode. If sinus rhythm was not achieved at 200 J, a single crossover shock (200 J) was applied. Defibrillation threshold, total delivered energy, number of shocks, and success rate were compared between groups. Results We included 100 patients, 50 in each group. In the active compression group, defibrillation threshold was lower (103.1 ± 49.9 J vs 130.4 ± 47.7 J; P = .008), as well as total delivered energy (203 ± 173.3 J vs 309 ± 213.5 J; P = .0076) and number of shocks (2.2 ± 1.1 vs 2.9 ± 1.2; P = .0033), and cardioversion was more often successful (48 of 50 patients [96%] vs 42 of 50 patients [84%]; P = .0455) than that in the standard anterior-posterior group. Crossover from the compression group to the standard group was not successful (0 of 2 patients), whereas crossover from the standard group to the compression group was successful in 50% of patients (4 of 8). Conclusion Active compression applied to the anterior defibrillation electrode is more effective for persistent AF cardioversion than standard anterior-posterior cardioversion, with lower defibrillation threshold and higher success rate.

Experimental data suggest that shifts in the site of origin of the sinus node (SN) correlate with changes in heart rate and P wave morphology. The direct visualization of the effect of respiration on SN electrical activation has not yet been reported in humans. We aimed to measure the respiratory shifting of the SN activation using ultra-high-density mapping. Sequential right atrial (RA) activation mapping during sinus rhythm (SR) was performed. Three maps were acquired for each patient: basal end-expiratory (Ex), end-inspiratory (Ins), and end-expiratory under isoproterenol (Iso). The earliest activation site (EAS) was defined as the earliest unipolar electrograms (EGM) with a QS pattern and was localized with respect to the ostium of the superior vena cava (SVC; negative values if EAS inside the SVC). In 20 patients, 49 maps in SR were acquired (20 Ex, 19 Ins, and 10 Iso). Expiratory (944 ± 227 ms) and inspiratory (946 ± 227 ms) SR cycle lengths were similar, but shortened under isoproterenol (752 ± 302 ms). Activation was unicentric in 33 maps and multicentric in 16: 4 during Ins, 10 during Ex, and 2 Iso. EAS location was significantly more cranial in expiration than in inspiration (0.27 ± 12.1 vs 5 ± 11.51 mm, p = 0.01). Iso infusion tends to induce a supplemental cranial shift (−4.07 ± 15.83 vs 0.27 ± 12.7 mm, p = 0.21). EAS were found in SVC in 22.7% of maps (30% Ex, 21% Ins, and 8% Iso). Inspiration induces a significant caudal shift of the earliest sinus activation. In one-third of the cases, sinus rhythm earliest activation is inside the SVC.

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.

Background: Ultrasound-guided axillary venous puncture (UGAVP) for cardiac devices implantation has been developed because of its rapidity, safety and potential long-term lead protection. Early work excluded defibrillators (ICD), cardiac resynchronization therapy (CRT) and upgrade procedures. Compared to the cephalic approach, in previous studies, there was a greater use of pressure dressings with this technique, suggesting a higher risk of bleeding. Aims: To assess UGAVP in patients under antithrombotic therapy (ATT) undergoing cardiac devices implantation including CRT/ICD. Methods: Prospectively, consecutive patients eligible for a pacemaker or ICD implantation were included. All procedures were performed by a single operator, experienced with UGAVP for femoral access, and fluoroscopy-guided axillary vein access. Guidewires insertion time (from lidocaïne administration), and complications were systematically studied. Results: From 457 cardiac device implantations, 200 patients (77.8 ± 10 y, male 58%) 360 leads were implanted by UGAVP including 36 ICD, 54 CRT and 14 upgrade procedures. A majority (90%) was under ATT: Vitamin K Antagonist or Heparin (n = 58, 29%), direct oral anticoagulant (n = 46, 23%), dual antithrombotic therapy (n = 18, 9%) and single antiplatelet drug (n = 82, 41%). UGAVP was successful in 95.78%. Mean insertion time for 1.8 guidewires per patient was 4.68 ± 3.6 min. No complication (no hematoma) was observed during the follow-up (mean of 45 ± 10 months). Guidewires insertion time reached its plateau after 15 patients. Conclusion: UGAVP is fast, feasible and safe for patients under ATT undergoing device implantation including CRT/ICD and upgrade procedures, with a short learning curve. Keywords: Cardiac devices implantation, Vascular complications, Ultrasound guidance, Antithrombotic therapy

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: In patients with complete atrioventricular block (AVB), the prevalence and clinical characteristics of patients with pause-dependent AVB (PD-AVB) is not known. Our objective was to assess the prevalence of PD-AVB in a population of patients with complete (or high-grade) AVB. Methods: Twelve-lead electrocardiogram (ECG) and/or telemonitoring from patients admitted (from September 2020 to November 2021) for complete (or high-degree) AVB were prospectively collected at the University Hospital of Nice. The ECG tracings were analyzed by an electrophysiologist to determine the underlying mechanism of PD-AVB. Results: 100 patients were admitted for complete (or high-grade) AVB (men 55%; 82 ± 12 years). Arterial hypertension was present in 68% of the patients. Baseline QRS width was 117 ± 32 ms, and mean left ventricular ejection fraction was 56 ± 7%. Fourteen patients (14%) with PD-AVB were identified, and presented similar clinical characteristics in comparison with patients without PD-AVB, except for syncope (which was present in 86% versus 51% in the non-PD-AVB patients, p = 0.01). PD-AVB sequence was induced by: Premature atrial contraction (8/14), premature ventricular contraction (5/14), His extrasystole (1/14), conduction block in a branch (1/14), and atrial tachycardia termination (1/14). All patients with PD-AVB received a dual-chamber pacemaker during hospitalization. Conclusion: The prevalence of PD-AVB was 14%, and may be underestimated. PD-AVB episodes were more likely associated with syncope in comparison with patients without PD-AVB.

Background: Female gender, degree of QT prolongation, and genetic susceptibility are known risk factors for developing torsades de pointes (TdP) during high-grade atrioventricular block (HG-AVB). Our objective was to analyze the prevalence and clinical characteristics of patients presenting with TdP and AVB (TdP [+]) in comparison with non-TdP patients with AVB (TdP [−]). Methods: All the ECGs from patients prospectively admitted for AVB (2 to 1, HG, and complete) at the University Hospital of Nice were analyzed. Automated corrected QT (QTc), manual measurements of QT and JT intervals, and Tpeak-to-end were performed at the time of the most severe bradycardia. Results: From September 2020 to November 2021, 100 patients were admitted for HG-AVB. Among them, 17 patients with TdP were identified (8 men; 81 ± 10 years). No differences could be identified concerning automated QTc, manual QTc (Bazett correction), baseline QRS width, or mean left ventricular ejection fraction between the two groups. Potassium serum level on admission and mean number of QT-prolonging drugs per patient were not significantly different between the two groups, respectively: 4.34 ± 0.5 mmol/L in TdP [+] versus 4.52 ± 0.6 mmol/L (p = 0.33); and 0.6 ± 0.7 in TdP [+] versus 0.3 ± 0.5 (p = 0.15). In contrast, manual QTcFR (Fridericia correction), JT (Fridericia correction), Tpeak-to-end, and Tpe/QT ratio were significantly increased in the TdP [+] group, respectively: 486 ± 70 ms versus 456 ± 53 ms (p = 0.04); 433 ± 98 ms versus 381 ± 80 ms (p = 0.02); 153 ± 57 ms versus 110 ± 40 ms (p < 0.001); and 0.27 ± 0.08 versus 0.22 ± 0.06 (p < 0.001). Conclusions: The incidence of TdP complicating acquired AVB was 17%. Longer QTcFR, JT, and Tpeak-to-end were significantly increased in the case of TdP but also in the presence of permanent AVB during the hospitalization.

ObjectivesSeverity of a first pulmonary embolism (PE) is sometimes proposed as a criterion for prolonging anticoagulant treatment. However, little evidence supports this idea. We attempted to determine the connection between severity of first PE and the risk of recurrence.ParticipantsPatients admitted with PE between 2012 and 2018 and for whom anticoagulant treatment had been discontinued were followed. PEs were classified according to the severity into the following two groups: those with associated cardiac involvement (increased cardiac biomarker(s) and/or echocardiographic right ventricular dysfunction) and those with no cardiac involvement which were classified as non-severe. Recurrence-free survivals were estimated using the Kaplan-Meier method and compared using the log-rank test.Results417 patients with PEs (186 with cardiac involvement) were followed for at least 1 year after discontinuation of treatment with a mean follow-up of: 3.5±1.9 years. 72 patients (17.3%) experienced venous thromboembolism recurrence: 24 (5.8%), 44 (12 %) and 72 (28.3 %) respectively, at 1, 2 and 5 years. In 63 patients (88%), recurrence was a PE. Mean time to onset of recurrence was 24.9±19.9 months. At 5 years, the recurrence rate is higher when the first PE was associated with cardiac involvement p=0.043. In contrast, in patients with provoked PE, the recurrence rate is higher when the first PE event was associated with cardiac involvement: p=0.032. Multivariate analysis demonstrates that PE severity is an independent factor of recurrence (HR 1.634 (1.015–2.632), p=0.043).ConclusionWe report for the first time a possible link between a higher recurrence rate and the severity of the first PE. This result which must be confirmed in a dedicated prospective trial could become an important criterion for the duration of anticoagulant therapy after a PE.Trial registration numberNCT04980924.

A 20-year-old patient is admitted to the emergency room for chest pain occurring in the context of recurrent left complete pneumothorax. Ultrasensitive troponinemia is elevated to 20 times normal. Myocardial distress is attributed to pneumothorax following the negativity of cardiological examinations (EKG, TTE, cardiac MRI). The pneumothorax is drained with a favorable evolution. This is the first reported case of pneumothorax associated with a significant elevation of troponin without ECG change, TakoTsubo syndrome, or myocardial inflammation. Several mechanisms are considered: rotation of the myocardium around its axis, increase in pulmonary vascular resistance with overload of right ventricular pressure, disturbance of coronary blood flow on significant mediastinal compression with decrease in systolo-diastolic myocardial perfusion.

Background: Whether unidirectional conduction block (UB) can be observed after creation of a radiofrequency (RF) line is still debated. Previous studies reported a prevalence of 9 to 33% of UB, but the assessment was performed using a point-by-point recording across the line. Ultra-high-density (UHD) system may bring some new insights on the exact prevalence of UB. Purpose: A prospective study was conducted to assess the prevalence of UB and bidirectional block (BB) using UHD system after RF line creation. Methods: Patients referred for atrial RF ablation procedure were included in this multicenter prospective study. UHD maps were performed by pacing both sides of the created line. Results: A total of 80 maps were created in 40 patients (67 ± 12 years, 70% male) by pacing (mean cycle length 600 ± 57 ms) from both sides of the cavotricuspid isthmus line. After a 47 ± 17 min waiting time after the last RF application, UHD maps (mean number of 4842 ± 5010 electrograms, acquired during 6 ± 5 min) showed that BB was unambiguously confirmed on all of them. UB was not observed in any map. After a mean follow-up of 12 ± 4 months, 6 (14%) patients experienced an arrhythmia recurrence. Conclusion: After creation of an RF line, no case of UB was observed using UHD mapping, suggesting that the presence of a conduction block along a RF line is always associated with a block in the opposite direction.

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.

Association between Hydroxychloroquine (HCQ) and Azithromycin (AZT) is under evaluation for patients with lower respiratory tract infection (LRTI) caused by the Severe Acute Respiratory Syndrome (SARS‐CoV‐2). Both drugs have a known torsadogenic potential, but sparse data are available concerning QT prolongation induced by this association. Our objective was to assess for COVID‐19 LRTI variations of QT interval under HCQ/AZT in patients hospitalized, and to compare manual versus automated QT measurements. Before therapy initiation, a baseline 12 lead‐ECG was electronically sent to our cardiology department for automated and manual QT analysis (Bazett and Fridericia’s correction), repeated 2 days after initiation. According to our institutional protocol (Pasteur University Hospital), HCQ/AZT was initiated only if baseline QTc ≤ 480ms and potassium level > 4.0 mmol/L. From March 24th to April 20th 2020, 73 patients were included (mean age 62 ± 14 y, male 67 %). Two patients out of 73 (2.7 %) were not eligible for drug initiation (QTc ≥ 500ms). Baseline average automated QTc was 415 ± 29 ms and lengthened to 438 ± 40 ms after 48 hours of combined therapy. The treatment had to be stopped because of significant QTc prolongation in 2 out of 71 patients (2.8 %). No drug‐induced life‐threatening arrhythmia, nor death was observed. Automated QTc measurements revealed accurate in comparison with manual QTc measurements. In this specific population of inpatients with COVID‐19 LRTI, HCQ/AZT could not be initiated or had to be interrupted in less than 6% of the cases.

BACKGROUND Remote magnetic navigation (RMN) and contact force (CF) sensing catheters are available technologies for radiofrequency (RF) catheter ablation of atrial fibrillation (AF). Our purpose was to compare time to electrogram (EGM) modification suggesting transmural lesions between RMN and CF-guided AF ablation. METHODS AND RESULTS A total of 1,008 RF applications were analyzed in 21 patients undergoing RMN (n = 11) or CF-guided ablation (n = 10) for paroxysmal AF. All procedures were performed in sinus rhythm during general anesthesia. Time to EGM modification was measured until transmurality criteria were fulfilled: (1) complete disappearance of R if initial QR morphology; (2) diminution > 75% of R if initial QRS morphology; (3) complete disappearance of R' of initial RSR' morphology. Impedance drop as well as force time integral (FTI) were also assessed for each application. Mean CF at the beginning of each RF application in the CF group was 11 ± 2 g and mean FTI per application was 488 ± 163 gs. Time to EGM modification was significantly shorter in the RMN group (4.52 ± 0.1 seconds vs. 5.6 ± 0.09 seconds; P < 0.00001). There was no significant difference between other procedural parameters. CONCLUSION Remote magnetic AF ablation is associated with faster EGM modification suggesting transmurality than optimized CF and FTI-guided catheter ablation.

Background The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in tetralogy of Fallot. Purpose To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD). Methods The DAI-T4F study is an ongoing national French registry including all patients with tetralogy of Fallot and ICD ( NCT03837574 ). Information have been collected prospectively since 2010. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Results A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively (P = 0.058). Overall, QRSd ≥ 180ms (P = 0.073), QRS fragmentation (P = 0.052), and QRS vector magnitude (vm, P = 0.327) were not significantly associated with appropriate ICD therapies, whereas the association of QRSd ≥ 180ms and QRS fragmentation (HR = 1.9, 95% CI: 1.1–3.4, P = 0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with events during follow-up (P = 0.069), combinations with QRSd ≥ 180 ms (HR = 7.2, 95% CI: 1.6–32.7, P = 0.011), QRS fragmentation (HR = 3.8, 95% CI: 1.2–12.4, P = 0.025), or decreased QRS vm (HR = 3.6, 95% CI: 1.1–12.1, P = 0.042) were all associated with a higher incidence of appropriate ICD therapies. Conclusions Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.