High-density mapping of the average complex interval helps localizing atrial fibrillation drivers and predicts catheter ablation outcomes

BackgroundPersistent Atrial Fibrillation (PersAF) electrogram-based ablation is complex, and appropriate identification of atrial substrate is critical. Little is known regarding the value of the Average Complex Interval (ACI) feature for PersAF ablation.ObjectiveUsing the evolution of AF complexity by sequentially computing AF dominant frequency (DF) along the ablation procedure, we sought to evaluate the value of ACI for discriminating active drivers (AD) from bystander zones (BZ), for predicting AF termination during ablation, and for predicting AF recurrence during follow-up.MethodsWe included PersAF patients undergoing radiofrequency catheter ablation by pulmonary vein isolation and ablation of atrial substrate identified by Spatiotemporal Dispersion or Complex Fractionated Atrial Electrograms (>70% of recording). Operators were blinded to ACI measurement which was sought for each documented atrial substrate area. AF DF was measured by Independent Component Analysis on 1-minute 12-lead ECGs at baseline and after ablation of each atrial zone. AD were differentiated from BZ either by a significant decrease in DF (>10%), or by AF termination. Arrhythmia recurrence was monitored during follow-up.ResultsWe analyzed 159 atrial areas (129 treated by radiofrequency during AF) in 29 patients. ACI was shorter in AD than BZ (76.4 ± 13.6 vs. 86.6 ± 20.3 ms; p = 0.0055), and mean ACI of all substrate zones was shorter in patients for whom radiofrequency failed to terminate AF [71.3 (67.5–77.8) vs. 82.4 (74.4–98.5) ms; p = 0.0126]. ACI predicted AD [AUC 0.728 (0.629–0.826)]. An ACI < 70 ms was specific for predicting AD (Sp 0.831, Se 0.526), whereas areas with an ACI > 100 ms had almost no chances of being active in AF maintenance. AF recurrence was associated with more ACI zones with identical shortest value [3.5 (3–4) vs. 1 (0–1) zones; p = 0.021]. In multivariate analysis, ACI < 70 ms predicted AD [OR = 4.02 (1.49–10.84), p = 0.006] and mean ACI > 75 ms predicted AF termination [OR = 9.94 (1.14–86.7), p = 0.038].ConclusionACI helps in identifying AF drivers, and is correlated with AF termination and AF recurrence during follow-up. It can help in establishing an ablation plan, by prioritizing ablation from the shortest to the longest ACI zone

Technological advances in cardiac pacing and defibrillation

Since more than a half century, cardiac pacing and defibrillation represent a field in constant evolution, and they have shown some great technological advances from its conception to its methods of insertion. In this review, the recent developments about the accesses for pacemakers and ICD will be described: the axillary and the femoral vein. The His bundle pacing and the advantages of the entirely subcutaneous defibrillator will also be presented

Evaluation des complications hémorragiques et thrombotiques post implantation de prothèse cardiaque (gestion des traitements antithrombotiques)

NICE-BU Médecine Odontologie (060882102) / SudocSudocFranceF

Atrial fibrillation ablation in a single atrium with inferior vena cava interruption

Abstract Common atrium (CA), also called three‐chambered heart, is one of the rare congenital anomalies, defined by a complete absence of the atrial septum, eventually associated with malformation of the atrioventricular (AV) valves. We report the case of a 57‐year‐old woman with CA complicated with Eisenmenger syndrome and inferior vena cava interruption, who suffered from symptomatic persistent atrial fibrillation (AF). She underwent an initial successful pulmonary vein isolation procedure. A repeat procedure for perivalvular atrial flutter was complicated with inadvertent complete AV block, due to unusual AV node location in this challenging anatomy

111 “New” echocardiographic isovolumetric parameters combined with standard parameters for the assessment of left ventricular filling pressures

Left ventricular filling pressures’ evaluation is still challenging. The ratio of the transmitral and myocardial early diastolic velocities (E/E’) can be used to estimate LV filling pressures (LVFP), but between 8 and 15 it remains unclear. Additionally, the time difference between the onset of E and E’ (Δ (RE-E’)), the time difference between onset of mitral inflow and onset of early diastolic mitral annulus velocity (Δ (IVRT-IVRT’)) and the mitral early diastolic velocity (E)/Strain rate ratio during the isovolumetric relaxation period also correlate to LVFP. The aim of this study was to evaluate the incremental value of those indices to evaluate LVFP (as measured by left ventricular end diastolic pressure (LVEDP)) in a heterogeneous group of patients during a simultaneous invasive procedure.Simultaneous cardiac catheterization, BNP dosage and doppler echocardiography were performed in 30 patients. LVEDP was elevated (>16mm Hg) in 14 patients (46,7%). The 3 previously described “new” parameters are significantly correlated to LVEDP, but particularly highly significant correlation was found between Δ (IVRT-IVRT’) and LVEDP (r=−0,74, p<0,005). ROC curves predict a 80% sensibility and specificity of Δ (IVRT-IVRT’). Δ (RE-E’) sensibility and specificity at lateral site are 87% and 93% respectively. E/SRivr has a 71% sensibility and a specificity. The incremental diagnostic value of each parameter and BNP in combination with “classic” parameters (E/A, E/E’) was evaluated by kappa coefficient. Δ (IVRT-IVRT’) at septal site (k=0,777) and Δ (RE-E’) (k=0,73) are the most accurate parameters, whereas additional use of E/SRivr (k=0,41) isn’t more useful than “classic” echocardiographic strategy (k=0,478) such as BNP (k=0,533).Δ (IVRT-IVRT’) and Δ (RE-E’) can predict LV filling pressures with reasonable accuracy

Prevalence and Clinical Characteristics of Patients with Torsades de Pointes Complicating Acquired Atrioventricular Block

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 [&minus;]). 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 &plusmn; 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 &plusmn; 0.5 mmol/L in TdP [+] versus 4.52 &plusmn; 0.6 mmol/L (p = 0.33); and 0.6 &plusmn; 0.7 in TdP [+] versus 0.3 &plusmn; 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 &plusmn; 70 ms versus 456 &plusmn; 53 ms (p = 0.04); 433 &plusmn; 98 ms versus 381 &plusmn; 80 ms (p = 0.02); 153 &plusmn; 57 ms versus 110 &plusmn; 40 ms (p &lt; 0.001); and 0.27 &plusmn; 0.08 versus 0.22 &plusmn; 0.06 (p &lt; 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

Fibrillatory Wave Amplitude Evolution during Persistent Atrial Fibrillation Ablation: Implications for Atrial Substrate and Fibrillation Complexity Assessment

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 &lt; 10%; II 10&ndash;20%; III 20&ndash;30%; IV &gt; 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 &plusmn; 0.68 vs. 4.95 &plusmn; 0.58 Hz, p &lt; 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 &lt; 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 &plusmn; 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

Prevalence and Clinical Characteristics of Patients with Pause-Dependent Atrioventricular Block

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

Does Unidirectional Block Exist after a Radiofrequency Line Creation? Insights from Ultra-High-Density Mapping (The UNIBLOCK Study)

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

QT Interval Prolongation Under Hydroxychloroquine/Azithromycin Association for Inpatients With SARS‐CoV‐2 Lower Respiratory Tract Infection

International audienc