Local VA index for the differential diagnosis of supraventricular tachycardia.

BACKGROUND: Differentiating between atypical atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic reciprocating tachycardia utilizing a septal accessory pathway is a complex challenge. OBJECTIVE: The purpose of this study was to describe the "local VA index," a straightforward method based on signals from the coronary sinus catheter, to distinguish between these arrhythmias during tachycardia and entrainment. The ventriculoatrial (VA) interval on the coronary sinus catheter is measured during tachycardia and entrainment, at the site of earliest atrial activity. The difference between these 2 situations defines the "local VA index." We also propose a mechanism to clarify the limitations of historical pacing maneuvers, such as postpacing interval minus tachycardia cycle length (PPI-TCL) and stimulus-atrial interval minus ventriculoatrial interval (SA-VA), by examining nodal decrement and intraventricular conduction delay. METHODS: In a retrospective study of 75 patients referred for supraventricular tachycardia evaluation, 37 were diagnosed with atrioventricular reentrant tachycardia (AVRT) with orthodromic reciprocating tachycardia, and 38 with AVNRT (27 typical, 11 atypical). RESULTS: In comparison to AVRT patients, AVNRT patients exhibited longer PPI-TCL (176 ± 47 ms vs 113 ± 42 ms; P <.01) and SA-VA (138 ± 47 ms vs 64 ± 28 ms; P <.01). The AVRT group had mean local VA index of -1 ± 13 ms, whereas the AVNRT group had a significantly longer index of 91 ± 46 ms (P <.01). An optimal threshold for differentiation was a local VA index of 40 ms. Importantly, there was no significant correlation between pacing cycle length and nodal decrement as well as intraventricular delay related to pathway location. This interindividual variability might explain misleading interpretations of PPI-TCL and SA-VA. CONCLUSION: This novel approach is advantageous because of its simplicity and effectiveness, requiring only 2 diagnostic catheters. A local VA interval difference <40 ms provides a clear distinction for AVRT.

Remote management of worsening heart failure to avoid hospitalization in a real-world setting.

AIMS: From a patient and health system perspective, managing worsening heart failure (WHF) as an outpatient has become a priority. Remote management allows early detection of WHF, enabling timely intervention with the aim of preventing hospitalization. The objective of the study was to evaluate the feasibility and safety of remotely managing WHF events using a multiparametric platform. METHODS AND RESULTS: All patients enrolled in the heart failure remote management programme of the Bordeaux University Hospital Telemedicine Center between 1 January and 31 December 2021 were included in the study. Follow-up data were collected until 1 March 2022. Inclusion criteria were chronic heart failure (HF) with New York Heart Association ≥II symptoms and an elevated B-type natriuretic peptide (BNP > 100 pg/mL or N-terminal-pro-BNP > 1000 pg/mL). Patient assessments were performed remotely and included measurements of body weight, blood pressure, heart rate, symptoms, biochemical parameters, and data from cardiac implantable electronic devices when available. In total, 161 patients (71 ± 11 years old, 79% male) were followed for a mean of 291 ± 66 days with a mean adherence to the remote monitoring system of 80 ± 20%. Over this period, 52 (32.3%) patients had 105 WHF events, of which 66 (63%) were successfully managed remotely, the remaining requiring hospitalization. Freedom from WHF events and hospitalization at 300 days were 66% and 85%, respectively (P < 0.001 for the difference). Increased level of BNP was associated with an increased risk of WHF event [hazard ratio (HR) per unit increase in BNP: 1.001; 95% confidence interval (CI) 1-1.002; P = 0.001] and hospitalization (HR 1.002; 95% CI 1.002-1.003; P = 0.002). A decrease in the level of glomerular filtration rate was associated with an increased risk of hospitalization (HR per unit decrease in estimated glomerular filtration rate: 0.946; 95% CI 0.906-0.989; P = 0.014). WHF event recurrence and (re)hospitalization rates at 1-month were similar among patients managed remotely (18% and 12%, respectively) and those requiring hospitalization (21% and 10%, respectively). Iatrogenic complications occurred more often during hospitalization than remote management (26% vs. 3%, P < 0.001). CONCLUSIONS: Our study suggests that remote management of WHF events based on a multiparametric approach led by a telemedical centre is feasible and safe. Adopting such a strategy for patients with chronic HF could reduce HF-related hospitalizations with expected benefits for patients, care providers, and health care systems.

Omnipolar versus bipolar mapping to guide ventricular tachycardia ablation.

BACKGROUND: Omnipolar technology (OT) was recently proposed to generate electroanatomic voltage maps with orientation-independent electrograms. We describe the first cohort of patients undergoing ventricular tachycardia (VT) ablation guided by OT. OBJECTIVE: The purpose of this study was to compare omnipolar and bipolar high-density maps with regard to voltage amplitude, late potential (LP) annotation, and isochronal late activation mapping distribution. METHODS: A total of 24 patients (16 [66%] ischemic cardiomyopathy and 12 [50%] redo cases) underwent VT ablation under OT guidance. Twenty-seven sinus rhythm substrate maps and 10 VT activation maps were analyzed. Omnipolar and bipolar (HD Wave Solution algorithm, Abbott, Abbott Park, IL) voltages were compared. Areas of LPs were correlated with the VT isthmus areas, and late electrogram misannotation was evaluated. Deceleration zones based on isochronal late activation maps were analyzed by 2 blinded operators and compared to the VT isthmuses. RESULTS: OT maps had higher point density (13.8 points/cm2 vs 8.0 points/cm2). Omnipolar points had 7.1% higher voltages than bipolar points within areas of dense scar and border zone. The number of misannotated points was significantly lower for OT maps (6.8% vs 21.9%; P = .01), showing comparable sensitivity (53% vs 59%) but higher specificity (79% vs 63%). The sensitivity and specificity of detection of the VT isthmus in the deceleration zones were, respectively, 75% and 65% for OT and 35% and 55% for bipolar mapping. At 8.4 months, 71% freedom from VT recurrence was achieved. CONCLUSION: OT is a valuable tool for guiding VT ablation, providing more accurate identification of LPs and isochronal crowding due to slightly higher voltages.

Electrophysiological study prior to planned pulmonary valve replacement in patients with repaired tetralogy of Fallot.

AIM: Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However, risk stratifying remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) with or without subsequent ablation in patients with rTOF planned for pulmonary valve replacement (PVR). METHODS: We included all consecutive patients with rTOF referred to our institution from 2010 to 2018 aged ≥18 years for PVR. Right ventricular (RV) voltage maps were acquired and PVS was performed from two different sites at baseline, and if non-inducible under isoproterenol. Catheter and/or surgical ablation was performed when patients were inducible or when slow conduction was present in anatomical isthmuses (AIs). Postablation PVS was undertaken to guide implantable cardioverter-defibrillator (ICD) implantation. RESULTS: Seventy-seven patients (36.2 ± 14.3 years old, 71% male) were included. Eighteen were inducible. In 28 patients (17 inducible, 11 non-inducible but with slow conduction) ablation was performed. Five had catheter ablation, surgical cryoablation in 9, both techniques in 14. ICDs were implanted in five patients. During a follow-up of 74 ± 40 months, no sudden cardiac death occurred. Three patients experienced sustained VAs, all were inducible during the initial EP study. Two of them had an ICD (low ejection fraction for one and important risk factor for arrhythmia for the second). No VAs were reported in the non-inducible group (p < .001). CONCLUSION: Preoperative EPS can help identifying patients with rTOF at risk for VAs, providing an opportunity for targeted ablation and may improve decision-making regarding ICD implantation.

Advanced Imaging Integration for Catheter Ablation of Ventricular Tachycardia.

PURPOSE OF REVIEW: Imaging plays a crucial role in the therapy of ventricular tachycardia (VT). We offer an overview of the different methods and provide information on their use in a clinical setting. RECENT FINDINGS: The use of imaging in VT has progressed recently. Intracardiac echography facilitates catheter navigation and the targeting of moving intracardiac structures. Integration of pre-procedural CT or MRI allows for targeting the VT substrate, with major expected impact on VT ablation efficacy and efficiency. Advances in computational modeling may further enhance the performance of imaging, giving access to pre-operative simulation of VT. These advances in non-invasive diagnosis are increasingly being coupled with non-invasive approaches for therapy delivery. This review highlights the latest research on the use of imaging in VT procedures. Image-based strategies are progressively shifting from using images as an adjunct tool to electrophysiological techniques, to an integration of imaging as a central element of the treatment strategy.

What interventions do firefighter nurses carry out? / Quelles interventions effectuent les Infirmiers Sapeurs-Pompiers ?

INTRODUCTION: With the rarefaction of home medical visits, prehospital emergencies are ensured by the Mobile Emergency and Resuscitation Structures (SMUR) and the Firemen accompanied by Firefighters Nurses (FfNs). PURPOSE OF RESEARCH: The main objective of this work is to describe the pathologies managed by the FfNs of the Loire district according to their International Classification of Primary Care version 2 and the Clinical Classification of Diseases of the initial SMUR during all interventions performed in 2019. The secondary objective will be to determine the associated Emergency Care Nursing Protocols (PISU). RESULTS: Among the 2969 interventions and 5036 PISU performed, trauma and polytrauma are the most common pathologies treated. Outside of trauma, the most frequent conditions are chest pain, carbon monoxide poisoning, and cardiopulmonary arrest (CPA). Analgesic protocols are the most used PISU and in second place comes the absence of PISU application, chest pain protocols, adult CPA and glucose administration. CONCLUSIONS: FfNs occupy an increasingly important place in the French rescue chain. Thanks to a wide range of interventions and a great autonomy of action, they make it possible to greatly limit the number of SMUR medical teams leaving the hospital, especially in situations that do not require a doctor immediately.

Introduction: Avec la raréfaction des visites médicales à domicile, les urgences préhospitalières sont assurées par les Structures Mobiles d'Urgence et de Réanimation (SMUR) et les Sapeurs-Pompiers accompagnés d'Infirmiers Sapeurs-Pompiers (ISP). Objectifs: L'objectif principal de ce travail est de décrire les pathologies prises en charge par les ISP de la Loire en fonction de la Classification internationale des soins primaires version 2 et de la Classification Clinique des Malades du SMUR initiales, lors de toutes les interventions effectuées en 2019. L'objectif secondaire sera de déterminer quels Protocoles Infirmiers de Soins d'Urgence (PISU) sont mobilisés. Résultats: Parmi les 2 969 interventions et 5 036 PISU réalisés, les traumatismes et polytraumatismes sont les pathologies les plus prises en charge. Hors traumatologie, les plus fréquentes sont les douleurs thoraciques, « les expositions aux fumées d'incendie ¼ et les arrêts cardio-respiratoires (ACR). Pour les PISU, les protocoles d'antalgies sont les plus utilisés et en seconde position vient l'absence d'application de PISU, les protocoles douleur thoracique, l'ACR de l'adulte et le resucrage. Conclusions: Les ISP occupent une place de plus en plus importante en France dans la chaîne des secours. Grâce à un domaine d'intervention large et une grande autonomie d'action, ils permettent de limiter grandement les sorties des équipes médicales du SMUR, notamment dans des situations qui ne nécessitent pas de médecin immédiatement.

Smartwatch Electrocardiograms for Automated and Manual Diagnosis of Atrial Fibrillation: A Comparative Analysis of Three Models.

AIMS: The diagnostic accuracy of proprietary smartwatch algorithms and the interpretability of smartwatch ECG tracings may differ between available models. We compared the diagnostic potential for detecting atrial fibrillation (AF) of three commercially available smartwatches. METHODS: We performed a prospective, non-randomized, and adjudicator-blinded clinical study of 100 patients in AF and 100 patients in sinus rhythm, patients with atrial flutter were excluded. All patients underwent 4 ECG recordings: a conventional 12-lead ECG, Apple Watch Series 5®, Samsung Galaxy Watch Active 3®, and Withings Move ECG® in random order. All smartwatch ECGs were analyzed using their respective automated proprietary software and by clinical experts who also graded the quality of the tracings. RESULTS: The accuracy of automated AF diagnoses by Apple and Samsung outperformed that of Withings, which was attributable to a higher proportion of inconclusive ECGs with the latter (sensitivity/specificity: 87%/86% and 88%/81% vs. 78%/80%, respectively, p < 0.05). Expert interpretation was more accurate for Withings and Apple than for Samsung (sensitivity/specificity: 96%/86% and 94%/84% vs. 86%/76%, p < 0.05), driven by the high proportion of uninterpretable tracings with the latter (2 and 4% vs. 15%, p < 0.05). CONCLUSION: Diagnosing AF is possible using various smartwatch models. However, the diagnostic accuracy of their automated interpretations varies between models as does the quality of ECG tracings recorded for manual interpretation.

Using a smartwatch electrocardiogram to detect abnormalities associated with sudden cardiac arrest in young adults.

AIMS: Smartwatch electrocardiograms (ECGs) could facilitate the detection of sudden cardiac arrest (SCA)-associated abnormalities. We evaluated the feasibility of using smartwatch-derived ECGs for detecting SCA-associated abnormalities in young adults and its agreement with 12-lead ECGs. METHODS AND RESULTS: Twelve-lead and Apple Watch ECGs were registered in 155 healthy volunteers and 67 patients aged 18-45 years with diagnosis and ECG signs of long-QT syndrome (n = 10), Brugada syndrome (n = 12), ventricular pre-excitation (n = 19), hypertrophic cardiomyopathy (HCM, n = 13), and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC/D, n = 13). Cardiologists separately analysed 12-lead ECGs and the smartwatch ECGs taken from the left wrist (AW-I) and then from chest positions V1, V3, and V6 (AW-4). Compared with AW-I, AW-4 improved the classification of ECGs as 'abnormal', increasing the sensitivity from 64% to 89% (P < 0.01). Pre-excitation was detected in most cases using AW-I (sensitivity 89%) and in all cases using AW-4 (sensitivity 100%, P = 0.48 compared with AW-I, specificity 100% for both). Brugada was missed using AW-I but was detected in 11/12 patients using AW-4 (sensitivity 92%, specificity 100%, P = 0.003). Long QT was detected in 8/10 cases using AW-I (sensitivity 80%, specificity 100%) and in 9 patients using AW-4 (sensitivity 90%, specificity 100%, P > 0.99). Hypertrophic cardiomyopathy was correctly suspected using AW-I and AW-4 (sensitivity 92% and 85%, specificity 85%, and 100%, P > 0.99). AW-I was mostly (62%) considered normal in ARVC/D whereas AW-4 was useful in suspecting ARVC/D (100% sensitivity, 99% specificity, P = 0.004). CONCLUSIONS: Detection of SCA-associated ECG abnormalities (pre-excitation, Brugada patterns, long QT, and signs suggestive of HCM and ARVC/D) is possible with an ECG smartwatch.

Beyond the wrist: Using a smartwatch electrocardiogram to detect electrocardiographic abnormalities.

BACKGROUND: When worn on the wrist, smartwatch electrocardiograms may provide important but incomplete information. AIMS: We sought to evaluate the added benefit of placing the smartwatch on the ankle and on the chest to diagnose various electrocardiographic abnormalities compared with 12-lead electrocardiograms. METHODS: Two hundred and sixty patients with (n=189) or without (n=71) known cardiac disorders underwent 12-lead electrocardiogram and smartwatch electrocardiogram recordings of lead I (AW-I) and of leads I and II and pseudo chest leads V1 and V6 (AW-4). AW-I and AW-4 diagnoses (three-cardiologist consensus) were compared with 12-lead electrocardiogram diagnoses (three-cardiologist consensus) to calculate sensitivity and specificity. RESULTS: AW-I showed high accuracy for the diagnoses of atrial fibrillation (96% sensitivity, 91% specificity) and complete bundle branch block (85% sensitivity, 98% specificity). Compared with AW-I, AW-4 improved detection of an abnormal 12-lead electrocardiogram (91% vs. 80% sensitivity; P<0.01), atrial flutter/tachycardia (69% vs. 25% sensitivity; P=0.04), T-wave abnormalities (77% vs. 34% sensitivity; P<0.01), pathological Q-waves (41% vs. 7% sensitivity; P<0.01) and left anterior hemiblock (70% vs. 0% sensitivity; P=0.02). AW-4 also enabled better differentiation between atrioventricular block and sinus bradycardia (from 81% to 95% correct; P=0.03) and between atrial fibrillation and atrial flutter/tachycardia (from 71% to 89% correct; P=0.02), but not between bundle branch blocks (from 82% to 87% correct; P=0.57). CONCLUSIONS: A smartwatch electrocardiogram on the wrist accurately diagnoses atrial fibrillation and bundle branch block. Recording additional leads significantly improves the accuracy of detecting an abnormal electrocardiogram and repolarization changes, and also allows for better differentiation of brady- and tachyarrhythmias.

Left-axis deviation in patients with nonischemic heart failure and left bundle branch block is a purely electrical phenomenon.

BACKGROUND: Possible mechanisms of left-axis deviation (LAD) in the setting of left bundle branch block (LBBB) include differences in cardiac electrophysiology, structure, or anatomic axis. OBJECTIVE: The purpose of this study was to clarify the mechanism(s) responsible for LAD in patients with LBBB. METHODS: Twenty-nine patients with nonischemic cardiomyopathies and LBBB underwent noninvasive electrocardiographic imaging (ECGi), cardiac computed tomography, and magnetic resonance imaging in order to define ventricular electrical activation, characterize cardiac structure, and determine the cardiac anatomic axis. RESULTS: Sixteen patients had a normal QRS axis (NA) (mean axis 8° ± 23°), whereas 13 patients had LAD (mean axis -48° ± 13°; P <.001). Total activation times were longer in the LAD group (112 ± 25 ms vs 91 ± 14 ms; P = .01) due to delayed activation of the basal anterolateral region (107 ± 10 ms vs 81 ± 17 ms; P <.001). Left ventricular (LV) activation in patients with LAD was from apex to base, in contrast to a circumferential pattern of activation in patients with NA. Apex-to-base delay was longer in the LA group (95 ± 13 ms vs 64 ± 21 ms; P <.001) and correlated with QRS frontal axis (R2 = 0.67; P <.001). Both groups were comparable with regard to LV end-diastolic volume (295 ± 84 mL vs LAD 310 ± 91 mL; P = .69), LV mass (177 ± 33 g vs LAD 180 ± 37 g; P = .83), and anatomic axis. CONCLUSION: LAD in LBBB appears to be due to electrophysiological abnormalities rather than structural factors or cardiac anatomic axis.

Remote monitoring of patients with heart failure during the first national lockdown for COVID-19 in France.

Aims: Multiparametric remote monitoring of patients with heart failure (HF) has the potential to mitigate the health risks of lockdowns for COVID-19. We aimed to compare healthcare use, physiological variables, and HF decompensations during 1 month before and during the first month of the first French national lockdown for COVID-19 among patients undergoing remote monitoring. Methods and results: Transmitted vital parameters and data from cardiac implantable electronic devices were analysed in 51 patients. Medical contact was defined as the sum of visits and days of hospitalization. The lockdown was associated with a marked decrease in cardiology medical contact (118 days before vs. 26 days during, -77%, P = 0.003) and overall medical contact (180 days before vs. 79 days during, -58%, P = 0.005). Patient adherence with remote monitoring was 84 ± 21% before and 87 ± 19% during lockdown. The lockdown was not associated with significant changes in various parameters, including physical activity (2 ± 1 to 2 ± 1 h/day), weight (83 ± 16 to 83 ± 16 kg), systolic blood pressure (121 ± 19 to 121 ± 18 mmHg), heart rate (68 ± 10 to 67 ± 10 b.p.m.), heart rate variability (89 ± 44 to 78 ± 46 ms, P = 0.05), atrial fibrillation burden (84 ± 146 vs. 86 ± 146 h/month), or thoracic impedance (66 ± 8 to 66 ± 9 Ω). Seven cases of HF decompensations were observed before lockdown, all but one of which required hospitalization, vs. six during lockdown, all but one of which were managed remotely. Conclusions: The lockdown restrictions caused a marked decrease in healthcare use but no significant change in the clinical status of HF patients under multiparametric remote monitoring.

Defibrillation testing is mandatory in patients with subcutaneous implantable cardioverter-defibrillator to confirm appropriate ventricular fibrillation detection.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) remains a new technology requiring accurate assessment of the various aspects of its functioning. Isolated cases of delayed sensing of ventricular arrhythmia have been described. OBJECTIVE: The purpose of this multicenter study was to assess the quality of sensing during induced ventricular fibrillation (VF). METHODS: One hundred thirty-seven patients underwent induction of VF at the end of the S-ICD implantation. RESULTS: VF induction was successful in 133 patients (97%). Mean time to first therapy was 16.2 ± 3.1 seconds, with a substantial range from 12.5 to 27.0 seconds. Four different detection profiles were arbitrarily defined: (1) optimal detection (n = 39 [29%]); (2) undersensing with moderate prolongation of time to therapy (<18 seconds; n = 68 [51%]); (3) undersensing with significant prolongation of the time to therapy (>18 seconds; n = 19 [14%]); and (4) absence of therapy or prolonged time to therapy related to noise oversensing (n = 7 [6%]). In some of the patients in the last group, despite induction of VF the initial counter was never filled, the device did not charge the capacitors, and the shock was not delivered because of a sustained diagnosis of noise (n = 5). A manual shock by the device or an external shock had to be delivered to restore the sinus rhythm. CONCLUSION: Our study demonstrated a marked sensing delay leading to prolonged time to therapy in a large number of S-ICD patients. A few worrisome cases of noise oversensing inhibiting the therapies were detected. These results support the need for systematic intraoperative defibrillation testing.