Delineation of intracavitary electrograms for the automatic quantification of decrement-evoked potentials in the coronary sinus with deep-learning techniques.

Cardiac arrhythmias cause depolarization waves to conduct unevenly on the myocardial surface, potentially delaying local components with respect to a previous beat when stimulated at faster frequencies. Despite the diagnostic value of localizing the distinct local electrocardiogram (EGM) components for identifying regions with decrement-evoked potentials (DEEPs), current software solutions do not perform automatic signal quantification. Electrophysiologists must manually measure distances on the EGM signals to assess the existence of DEEPs during pacing or extra-stimuli protocols. In this work, we present a deep learning (DL)-based algorithm to identify decrement in atrial components (measured in the coronary sinus) with respect to their ventricular counterparts from EGM signals, for disambiguating between accessory pathways (APs) and atrioventricular re-entrant tachycardias (AVRTs). Several U-Net and W-Net neural networks with different configurations were trained on a private dataset of signals from the coronary sinus (312 EGM recordings from 77 patients who underwent AP or AVRT ablation). A second, separate dataset was annotated for clinical validation, with clinical labels associated to EGM fragments in which decremental conduction was elucidated. To alleviate data scarcity, a synthetic data augmentation method was developed for generating EGM recordings. Moreover, two novel loss functions were developed to minimize false negatives and delineation errors. Finally, the addition of self-attention mechanisms and their effect on model performance was explored. The best performing model was a W-Net model with 6 levels, optimized solely with the Dice loss. The model obtained precisions of 91.28%, 77.78% and of 100.0%, and recalls of 94.86%, 95.25% and 100.0% for localizing local field, far field activations, and extra-stimuli, respectively. The clinical validation model demonstrated good overall agreement with respect to the evaluation of decremental properties. When compared to the criteria of electrophysiologists, the automatic exclusion step reached a sensitivity of 87.06% and a specificity of 97.03%. Out of the non-excluded signals, a sensitivity of 96.77% and a specificity of 95.24% was obtained for classifying them into decremental and non-decremental potentials. Current results show great promise while being, to the best of our knowledge, the first tool in the literature allowing the delineation of all local components present in an EGM recording. This is of capital importance at advancing processing for cardiac electrophysiological procedures and reducing intervention times, as many diagnosis procedures are performed by comparing segments or late potentials in subsequent cardiac cycles.

Mortality and Costs of Cardiac Implantable Electronic Device (CIED) Infections According to the Therapeutic Approach: A Single-Center Cohort Study.

Background: Cardiac device infections are serious adverse events associated with considerable morbidity and mortality, significant costs, and increased healthcare utilization. The aim of this study is to calculate the costs of treatment of cardiac implantable electrostimulation device (CIED)-related infections for different types of infection (local or systemic) and therapeutic approaches. Patients and Methods: Single-center cohort (1985-2018). The costs of the CIED-related infections were analyzed according to initial treatment (antimicrobial treatment exclusively, local approach, or transvenous lead extraction (TLE)). Total costs (including those for hospitalization stay, drugs, extraction material, and newly implanted devices) were assigned to each case until its final resolution. Results: A total of 380 cases (233 local and 147 systemic infections) were analyzed. The average cost of systemic infection was EUR 34,086, mainly due to hospitalization (78.5%; mean: 24 ± 14 days), with a mortality rate of 10.8%. Local infection had a mortality rate of 2.5% (mainly related to the extraction procedure) and an average cost of EUR 21,790, which was higher in patients with resynchronization therapy devices and defibrillators (46% of total costs). Surgical procedures limited to the pocket for local infections resulted in a high rate of recurrence (87%), evolved to systemic infections in 48 patients, and had a higher cost compared to TLE (EUR 42,978 vs. EUR 24,699; p < 0.01). Conclusions: The costs of treating CIED-related infections are high and mainly related to the type of treatment and length of hospitalization. Complete device removal is always the most effective approach and is a cost-saving strategy.

Automated isochronal late activation mapping for substrate characterization in patients with repaired tetralogy of Fallot.

AIMS: Slow conduction (SC) anatomical isthmuses (AIs) are the dominant substrate for monomorphic ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTF). This study aimed to evaluate the utility of automated propagational analysis for the identification of SC-AI in patients with rTF. METHODS AND RESULTS: Consecutive rTF patients undergoing VT substrate characterization were included. Automated isochronal late activation maps (ILAM) were obtained with multielectrode HD Grid Catheter. Identified deceleration zones (DZs) were compared with both SC-AI defined by conduction velocity (CV) (<0.5 m/s) and isthmuses of induced VT for mechanistic correlation. Fourteen patients were included (age 48; p25-75 35-52 years; 57% male), 2 with spontaneous VT and 12 for risk stratification. Nine VTs were inducible in seven patients. Procedure time was 140 (p25-75 133-180) min and mapping time 29.5 (p25-75 20-37.7) min, using a median of 2167 points. All the patients had at least one AI by substrate mapping, identifying a total of 27 (11 SC-AIs). Isochronal late activation maps detected 10 DZs mostly in the AI between ventricular septal defect and pulmonary valve (80%). Five patients had no DZs. A significant negative correlation between number of isochrones/cm and CV was observed (rho -0.87; P < 0.001). Deceleration zones correctly identified SC-AI (90% sensitivity; 100% specificity; 0.94 accuracy) and was related to VT inducibility (P = 0.006). Deceleration zones co-localized to the critical isthmus of induced VTs in 88% of cases. No complications were observed. CONCLUSION: Deceleration zones displayed by ILAM during sinus rhythm accurately identify SC-AIs in rTF patients allowing a safe and short-time VT substrate characterization procedure.

Brugada syndrome masked by complete left bundle branch block: A clinical and functional study of its association with the p.1449Y>H SCN5A variant.

SCN5A gene variants are associated with both Brugada syndrome and conduction disturbances, sometimes expressing an overlapping phenotype. Functional consequences of SCN5A variants assessed by patch-clamp electrophysiology are particularly beneficial for correct pathogenic classification and are related to disease penetrance and severity. Here, we identify a novel SCN5A loss of function variant, p.1449Y>H, which presented with high penetrance and complete left bundle branch block, totally masking the typical findings on the electrocardiogram. We highlight the possibility of this overlap combination that makes impossible an electrocardiographic diagnosis and, through a functional analysis, associate the p.1449Y>H variant to SCN5A pathogenicity.

Long-Term Survival After Implantable Cardiac Defibrillator Therapy According to Sex: A Propensity Matched Study.

Background: Whether the sex factor influences the benefit of the implantable cardioverter-defibrillator (ICD) for the prevention of sudden death remains a subject of debate. Using a prospective registry, we sought to analyze the survival and time to first ICD therapy according to sex. Materials and Methods: Retrospective analysis of a prospective cohort of patients undergoing an ICD implant from 2008 to 2019. Data about time to first appropriate therapy, type of therapy administered, and incidence and causes of mortality were collected. Results: Among 756 ICD patients, 150 (19.8%) were women. Women were younger (51 ± 15 years vs. 61 ± 14 years; p < 0.001) and showed a lower rate of ischemic cardiomyopathy (23% vs. 54%; p < 0.001) and atrial fibrillation (12% vs. 19%; p = 0.05). Women had higher left ventricular ejection fraction (39% ± 17% vs. 35% ± 13%) and showed more frequently left bundle branch block (39% vs. 28%, p = 0.027). The rate of primary prevention (68% vs. 59.6%; p = 0.058) and cardiac resynchronization therapy (27% vs. 19%, p = 0.02) were higher in women. After a median follow-up of 46 months (3382 patient-years), the incidence of both the primary combined endpoint of mortality/transplant (20% vs. 29%; logrank = 0.031) and ICD therapies (27% vs. 34%; p = 0.138) were lower in women. According to the propensity score-matching analysis, no differences were observed between both sexes with respect to the incidence of mortality/transplant (24.8% vs. 28.6%; logrank = 0.88), ICD therapies (28% vs. 27%; logrank = 0.17), and main cause of death (heart failure [HF]). Conclusions: The clinical characteristics at the moment of ICD implant are different between sexes. After adjusting them, both sexes equally benefit from the ICD. HF is the main cause of mortality both in men and women.

Long-term outcomes of ventricular tachycardia substrate ablation incorporating hidden slow conduction analysis.

BACKGROUND: Ventricular tachycardia substrate ablation (VTSA) incorporating hidden slow conduction (HSC) analysis allows further arrhythmic substrate identification. OBJECTIVE: The purpose of this study was to analyze whether the elimination of HSC electrograms (HSC-EGMs) during VTSA results in better short- and long-term outcomes. METHODS: Consecutive patients (N = 70; 63% ischemic; mean age 64 ± 14.6 years) undergoing VTSA were prospectively included. Bipolar EGMs with >3 deflections and duration <133 ms were considered as potential HSC-EGMs. Whenever a potential HSC-EGM was identified, double or triple ventricular extrastimuli were delivered. If a local potential showed up as a delayed component, it was annotated as HSC-EGM. Ablation was delivered at conducting channel entrances and HSC-EGMs. Radiofrequency time, ventricular tachycardia (VT) inducibility after VTSA, and VT/ventricular fibrillation recurrence at 24 months after the procedure were compared with data from a historical control group. RESULTS: A total of 5076 EGMs were analyzed; 1029 (20.2%) qualified as potential HSC-EGMs, and 475 of them were tagged as HSC-EGMs. Scars in patients with HSC-EGMs (n = 43 [61.4%]) were smaller (32.2 [17-58] cm2 vs 85 [41-92.4] cm2; P = .006) and more heterogeneous (core/scar area ratio 0.15 [0.05-0.44] vs 0.44 [0.33-0.57]; P = .017); 32.4% of HSC-EGMs were located in normal voltage tissue. Patients undergoing VTSA incorporating HSC analysis required less radiofrequency time (15.6 [8-23.1] vs 23.9 [14.9-30.8]; P < .001) and had a lower rate of VT inducibility after VTSA (28.6% vs 52.9%; P = .003) than did the historical controls. Patients undergoing VTSA incorporating HSC analysis showed a higher 2-year VT/ventricular fibrillation-free survival (75.7% vs 58.8%; log-rank, P = .046) after VTSA. CONCLUSION: VTSA incorporating HSC analysis allowed further arrhythmic substrate identification (especially in the border zone and normal voltage areas) and was associated with increased VTSA efficiency and better short- and long-term outcomes.

Dramatic reduction of ventricular tachycardia burden after dronedarone plus mexiletine treatment in a patient refractory to hybrid ablation.

Antiarrhythmic drugs are often the last resort for recurrent ventricular tachycardia refractory to catheter ablation in implantable cardioverter-defibrillator carriers. Amiodarone, alone or combined with mexiletine, is usually but not always highly effective, and its use is usually limited by systemic adverse effects. We present the case of a 62 years old man with recurrent ICD shocks due to a VT refractory to an endo-epicardial hybrid ablation. Starting of dronedarone plus mexiletine combination showed an excellent result.

Analysis of late reconnections after pulmonary vein isolation: Impact of interlesion contiguity and ablation index.

BACKGROUND: Interlesion distance and ablation index (AI) have been proposed as parameters of radiofrequency (RF) lesion durability. This study analyzes the relationship between RF parameters of automatically acquired lesion tags and late reconnections in repeat pulmonary vein isolation (PVI) procedures. METHODS: One hundred fifty-seven patients underwent contact force (CF)-guided PVI with automatic acquisition of RF lesions. During follow-up, 21 patients underwent a repeat PVI procedure. The relationship between RF parameters (power, CF, impedance drop, and AI) of the initial PVI procedure and reconnections observed at repeat PVI was analyzed. Visual gap was defined as the existence of a discontinuity between two RF lesions automatically acquired in the initial PVI procedure. Regional values of AI associated with lesion durability were identified. RESULTS: Twenty-one patients were included. Three hundred thirty-six segments and 2507 RF lesions were analyzed. The median interval between the initial and repeat PVI procedures was 17 (11-24) months. All patients showed ≥1 reconnected segment. Sixty-three segments (18.7%) were reconnected. Reconnected segments showed visual gaps more frequently than non-reconnected segments (66.6% vs 17.6%; P < .001; negative predictive value 91.4%). The mean distance of visual gaps was 8 ± 2.8 mm. No differences were observed in power (31.4 ± 4.7 W vs 31 ± 4.1 W; P = .573), CF (14.4 ± 5.3 g vs 15.4 ± 5.4 g; P = .315), and impedance drop (6.9 ± 5.2 ohms vs 6.5 ± 3.8 ohms; P = .576) between reconnected and non-reconnected segments. Among segments without visual gap, the minimum AI value was significantly higher in the non-reconnected segments (325 ± 96.1 vs 204.7 ± 78.5; P < .001). No reconnections were observed in segments without visual gap and minimum AI ≥ 330/220 in anterior/posterior wall, respectively. CONCLUSIONS: Contiguity between automatically acquired RF lesions and minimum AI value are the main determinants of long-term PVI durability.

Sedación profunda basada en propofol y administrada por electrofisiólogos en la ablación de la fibrilación auricular / Deep sedation with propofol administered by electrophysiologists in atrial fibrillation ablation

No disponible

Implante de un marcapasos sin cables en un paciente con deformidad torácica grave / Leadless pacemaker implantation in a patient with a severe thoracic deformity

No disponible

Clinical validation of automatic local activation time annotation during focal premature ventricular complex ablation procedures.

Aims: Current navigation systems incorporate algorithms for automatic identification of local activation time (LAT). However, data about their utility and accuracy in premature ventricular complex (PVC) ablation procedures are scarce. This study analyses the accuracy of an algorithmic method based on automatic annotation of the maximal negative slope of the unipolar electrogram within the window demarcated by the bipolar electrogram compared with conventional manual annotation during PVC ablation procedures. Methods and results: Forty patients with successful ablation of focal PVC in three centres were included. Electroanatomical activation maps obtained with the automatic system (WF-map) were compared with manual annotation maps (M-map). Correlation and concordance of LAT obtained with both methods were assessed at 3536 points. The distance between the earliest activation site (EAS) and the effective radiofrequency application point (e-RFp) were determined in M-map and WF-map. The distance between WF-EAS and M-EAS was assessed. Successful ablation sites included left ventricular outflow tract (LVOT; 55%), right ventricular outflow tract (40%), and tricuspid annulus (5%). Good correlation was observed between the two annotation approaches (r = 0.655; P < 0.0001). Bland-Altman analysis revealed a systematic delayed detection of LAT by WF-map (bias 33.8 ± 30.9 ms), being higher in LVOT than in the right ventricle (42.6 ± 29.2 vs. 27.2 ± 30.5 ms, respectively; P < 0.0001). No difference in EAS-eRFp distance was observed between M-map and WF-map (1.8 ± 2.8 vs. 1.8 ± 3.4 mm, respectively; P = 0.986). The median (interquartile range) distance between WF-EAS and M-EAS was 2.2(0-6) mm. Conclusion: Good correlation was found between M-map and WF-map. Local activation time detection was systematically delayed in WF-map, especially in LVOT. Accurate identification of e-RFp was achieved with both annotation approaches.

Yield of atrial fibrillation detection with Textile Wearable Holter from the acute phase of stroke: Pilot study of Crypto-AF registry.

BACKGROUND: We describe the feasibility of monitoring with a Textile Wearable Holter (TWH) in patients included in Crypto AF registry. METHODS: We monitored cryptogenic stroke patients from stroke onset (<3days) continuously during 28days. We employed a TWH composed by a garment and a recorder. We compared two garments (Lead and Vest) to assess rate of undiagnosed Atrial Fibrillation (AF) detection, monitoring compliance, comfortability (1 to 5 points), skin lesions, and time analyzed. We describe the timing of AF detection in three periods (0-3, 4-15 and 16-28days). RESULTS: The rate of undiagnosed AF detection with TWH was 21.9% (32 out of 146 patients who completed the monitoring). Global time compliance was 90% of the time expected (583/644h). The level of comfortability was 4 points (IQR 3-5). We detected reversible skin lesions in 5.47% (8/146). The comfortability was similar but time compliance (in hours) was longer in Vest group 591 (IQR [521-639]) vs. Lead 566 (IQR [397-620]) (p=0.025). Also, time analyzed was more prolonged in Vest group 497 (IQR [419-557]) vs. Lead (336h (IQR [140-520]) (p=0.001)). The incidence of AF increases from 5.6% (at 3days) to 17.5% (at 15th day) and up to 20.9% (at 28th day). The percentage of AF episodes detected only in each period was 12.5% (0-3days); 21.7% (4-15days) and 19% (16-28days). CONCLUSIONS: 28days Holter monitoring from the acute phase of the stroke was feasible with TWH. Following our protocol, only five patients were needed to screen to detected one case of AF.

Repeated procedures at the generator pocket are a determinant of implantable cardioverter-defibrillator infection.

BACKGROUND: Rates of cardiac-device infections have increased in recent years, but the current incidence and risk factors for infection in patients with implantable cardioverter-defibrillators (ICDs) are not well known. HYPOTHESIS: The increasing number of ICD infections is related to accumulated pocket manipulations over time. METHODS: This single-center, prospective study included patients that underwent ICD implantation from 2008 to 2015. The endpoint was time to infection. Multivariate analysis was performed to identify independent risk factors related to infection. RESULTS: The study included a total of 570 patients, of whom 419 (73.5%) underwent a first implantation. Mean age was 59 ± 14 years, and 80% were male. During a median follow-up of 36 months (interquartile range, 18-61 months; 1887 patient-years), infection was identified in 26 patients (4.56%), an incidence of 14.9 × 1000 patient-years. Median time to infection was 9.7 months (interquartile range, 1.35-23.4 months), and 38.5% were late infections (beyond 12 months of follow-up). In patients with replacement implants, the incidence was 3-fold higher than in first implantations (27.7 vs 9.1 × 1000 patient-years; P = 0.002). Cox regression identified 2 independent predictors of ICD infection: cumulative number of interventions at the generator pocket (hazard ratio: 1.92, 95% confidence interval: 1.42-2.6, P < 0.001) and pocket hematoma (hazard ratio: 7.0, 95% confidence interval: 2.7-17.9, P < 0.0001). CONCLUSIONS: The incidence of infection in ICD patients is greater than previously reported, largely due to late infections. Each new cumulative intervention at the same generator pocket nearly doubles the risk of infection.

Infecciones en dispositivos de estimulación cardiaca: diagnóstico y tratamiento en un centro de referencia / Infections in cardiac implantable electronic devices: diagnosis and management in a referral center

Introducción y objetivos: Las infecciones en dispositivos de electroestimulación cardiaca son cada vez más frecuentes debido a las indicaciones cada vez más amplias de estos sistemas. Algunos aspectos sobre su tratamiento son controvertidos y aportamos aquí nuestra amplia experiencia. Métodos: Se atendieron 325 infecciones (196 locales y 129 sistémicas) durante los años 1985 a 2015, el 28,5% de ellas procedentes de otros centros: 229 marcapasos, 69 desfibriladores automáticos implantables y 27 pacientes con terapia de resincronización cardiaca, con un seguimiento mínimo de 1 año tras el alta hospitalaria. Resultados: La tracción percutánea (TPC) fue la técnica utilizada más frecuentemente (n = 280), en infecciones tanto locales (n = 166) como sistémicas (n = 114), con una tasas de extracción completa del sistema del 82,5% del total y de curación, del 89%; las complicaciones fueron escasas (2 muertes achacables a la técnica). La mortalidad total fue del 1% en infecciones locales y el 8% en las sistémicas. Tras 212 TPC completas, se reimplantó un nuevo sistema contralateral en 209: en 152 de ellas en el mismo acto (73%) y en 57 en un segundo tiempo; no se apreciaron diferencias en el número de recidivas en el nuevo sistema (2 en 1 tiempo y 1 en 2 tiempos). Conclusiones: La TPC en manos expertas arroja buenos resultados en términos de eficacia, con escasas complicaciones. Se puede realizar el reimplante de dispositivos en un solo tiempo sin que ello conlleve un mayor riesgo de recidiva (AU)

Introduction and objectives: Infections in cardiac implantable electronic devices are increasing due to the expansion of the indications of these devices. The management of some aspects is controversial. Here, we report our broad experience. Methods: Between 1985 and 2015, 325 infections (196 local and 129 systemic) were registered; 28.5% of them were referred from other centers: 229 pacemakers, 69 implantable cardioverter-defibrillators, and 27 patients with cardiac resynchronization therapy. The follow-up was at least 1 year after hospital discharge. Results: Percutaneous traction (PCT) was the most frequent procedure (n = 280) in local (n = 166) and systemic infections (n = 114), with complete extraction of the system in 82.5% of the patients, clinical success in 89%, and few complications (2 deaths attributable to the technique). Overall mortality was 1% in local infections and 8% in systemic infections. After 212 complete PCT, a new device was placed in 209: of these, a contralateral system was implanted in the same procedure in 152 (73%) and in a second procedure in 57, with no differences in relapses (2 in the 1-stage procedure, and 1 in the 2-stage procedure). Conclusions: Percutaneous traction in experienced hands has good results with very few complications. It is possible to perform contralateral implantation of the new device on the same day without increasing the risk of relapse (AU)

Paroxysmal atrial fibrillation ablation: Achieving permanent pulmonary vein isolation by point-by-point radiofrequency lesions.

Pulmonary vein isolation by point-by-point radiofrequency catheter ablation constitutes the cornerstone of catheter ablation strategies for the treatment of atrial fibrillation. However, despite advances in pulmonary vein isolation ablation strategies, long-term success rates after ablation remain suboptimal, which highlights the need to develop techniques to achieve more durable lesions. Strategies proposed to improve the durability of pulmonary vein isolation can be divided into two groups: Those addressed to improving the quality of the lesion and those that optimize the detection of acute PV reconnection during the ablation procedure. This manuscript reviews the role and potential benefits of these techniques according to current clinical evidence.

Safety, long-term outcomes and predictors of recurrence after first-line combined endoepicardial ventricular tachycardia substrate ablation in arrhythmogenic cardiomyopathy. Impact of arrhythmic substrate distribution pattern. A prospective multicentre study.

BACKGROUND: First-line endoepicardial ventricular tachycardia (VT) ablation has been proposed for patients with arrhythmogenic cardiomyopathy (AC). This study reports procedural safety, outcomes, and predictors of recurrence. METHODS AND RESULTS: Forty-one consecutive patients [12 with left ventricle (LV) involvement, 7 left-dominant] underwent first-line endoepicardial VT substrate ablation. Standard bipolar and unipolar thresholds were used to define low-voltage areas (LVA). Arrhythmogenic substrate area (ASA) was defined as the area containing electrograms with delayed components. Implantable cardioverter defibrillator interrogations were evaluated for VT recurrence. Epicardial LVA was larger in all cases (102.5 ± 78.6 vs. 19.3 ± 24.4 cm2; P< 0.001). Consistent with an epicardium-to-endocardium arrhythmogenic substrate progression pattern, epicardial ASA (epi-ASA) was negatively correlated with bipolar endocardial LVA (r = -0.368; P= 0.035) and with endocardial bipolar/unipolar-LVA (Bi/Uni-LVA) ratio (r= -0.38; P= 0.037). A Bi/Uni-LVA ratio >0.23 predicted an epi-ASA ≤10 cm2 (100% sensitivity, 84% specificity). Patients showing an epi-ASA < 10 cm2 required less epicardial (8.4 ± 5.8 vs. 25.3 ± 16; P= 0.045) and more endocardial (16.5 ± 8.6 vs. 7.5 ± 8.2; P= 0.047) radiofrequency applications. One patient with epi-ASA < 10 cm2 died of cardiac tamponade after epicardial puncture. Acute success (no VT inducibility after procedure) was achieved in 36 patients (90%). After 32.2 ± 21.8 months, 11 (26.8%) patients had VT recurrences. Left-dominant AC was associated with an increased risk of recurrence (HR = 3.41 [1.1-11.2], P= 0.044; log-rank P= 0.021). CONCLUSION: First-line endoepicardial VT substrate ablation achieves good long-term results in AC. Left-dominant AC is associated with an increased risk of recurrence. The Bi/Uni-LVA ratio identifies patients with limited epicardial arrhythmogenic substrate in whom the indication of epicardial approach should be more cautiously assessed.