ABSTRACT
BACKGROUND: Sacubitril/valsartan (Sac/Val) is superior to angiotensin-converting enzyme inhibitors in reducing the risk of heart failure hospitalization and cardiovascular death, but its mechanistic data on myocardial scar after myocardial infarction (MI) are lacking. The objective of this work was to assess the effects of Sac/Val on inflammation, fibrosis, electrophysiological properties, and ventricular tachycardia inducibility in post-MI scar remodeling in swine. METHODS: After MI, 22 pigs were randomized to receive ß-blocker (BB; control, n=8) or BB+Sac/Val (Sac/Val, n=9). The systemic immune response was monitored. Cardiac magnetic resonance data were acquired at 2-day and 29-day post MI to assess ventricular remodeling. Programmed electrical stimulation and high-density mapping were performed at 30-day post MI to assess ventricular tachycardia inducibility. Myocardial samples were collected for histological analysis. RESULTS: Compared with BB, BB+Sac/Val reduced acute circulating leukocytes (P=0.009) and interleukin-12 levels (P=0.024) at 2-day post MI, decreased C-C chemokine receptor type 2 expression in monocytes (P=0.047) at 15-day post MI, and reduced scar mass (P=0.046) and border zone mass (P=0.043). It also lowered the number and mass of border zone corridors (P=0.009 and P=0.026, respectively), scar collagen I content (P=0.049), and collagen I/III ratio (P=0.040). Sac/Val reduced ventricular tachycardia inducibility (P=0.034) and the number of deceleration zones (P=0.016). CONCLUSIONS: After MI, compared with BB, BB+Sac/Val was associated with reduced acute systemic inflammatory markers, reduced total scar and border zone mass on late gadolinium-enhanced magnetic resonance imaging, and lower ventricular tachycardia inducibility.
Subject(s)
Aminobutyrates , Biphenyl Compounds , Cicatrix , Disease Models, Animal , Drug Combinations , Myocardial Infarction , Myocardium , Tachycardia, Ventricular , Valsartan , Ventricular Remodeling , Animals , Valsartan/pharmacology , Aminobutyrates/pharmacology , Myocardial Infarction/drug therapy , Myocardial Infarction/physiopathology , Myocardial Infarction/complications , Myocardial Infarction/pathology , Cicatrix/physiopathology , Cicatrix/etiology , Cicatrix/pathology , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/drug therapy , Tachycardia, Ventricular/prevention & control , Tachycardia, Ventricular/metabolism , Ventricular Remodeling/drug effects , Biphenyl Compounds/pharmacology , Myocardium/pathology , Myocardium/metabolism , Anti-Inflammatory Agents/pharmacology , Tetrazoles/pharmacology , Fibrosis , Swine , Anti-Arrhythmia Agents/pharmacology , Female , Male , Time Factors , Magnetic Resonance Imaging, Cine , Heart Rate/drug effectsABSTRACT
BACKGROUND: In preclinical studies, the use of double allogeneic grafts has shown promising results in promoting tissue revascularization, reducing infarct size, preventing adverse remodelling and fibrosis, and ultimately enhancing cardiac function. Building upon these findings, the safety of PeriCord, an engineered tissue graft consisting of a decellularised pericardial matrix and umbilical cord Wharton's jelly mesenchymal stromal cells, was evaluated in the PERISCOPE Phase I clinical trial (NCT03798353), marking its first application in human subjects. METHODS: This was a double-blind, single-centre trial that enrolled patients with non-acute myocardial infarction eligible for surgical revascularization. Seven patients were implanted with PeriCord while five served as controls. FINDINGS: Patients who received PeriCord showed no adverse effects during post-operative phase and one-year follow-up. No significant changes in secondary outcomes, such as quality of life or cardiac function, were found in patients who received PeriCord. However, PeriCord did modulate the kinetics of circulating monocytes involved in post-infarction myocardial repair towards non-classical inflammation-resolving macrophages, as well as levels of monocyte chemoattractants and the prognostic marker Meteorin-like in plasma following treatment. INTERPRETATION: In summary, the PeriCord graft has exhibited a safe profile and notable immunomodulatory properties. Nevertheless, further research is required to fully unlock its potential as a platform for managing inflammatory-related pathologies. FUNDING: This work was supported in part by grants from MICINN (SAF2017-84324-C2-1-R); Instituto de Salud Carlos III (ICI19/00039 and Red RICORS-TERAV RD21/0017/0022, and CIBER Cardiovascular CB16/11/00403) as a part of the Plan Nacional de I + D + I, and co-funded by ISCIII-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER) and AGAUR (2021-SGR-01437).
Subject(s)
Hematopoietic Stem Cell Transplantation , Wharton Jelly , Humans , Quality of Life , Heart , Umbilical CordSubject(s)
Humans , Male , Female , Middle Aged , Aged , Atrial Fibrillation/diagnostic imaging , Heart Atria/diagnostic imaging , Magnetic Resonance ImagingABSTRACT
BACKGROUND: In patients with persistent atrial fibrillation (PersAF), catheter ablation aiming for pulmonary vein isolation (PVI) is associated with moderate clinical effectiveness. We investigated the benefit of continuing previously ineffective class 1C or 3 antiarrhythmic drug therapy (ADT) in the setting of a standardized PVI-only ablation strategy. METHODS: In this multicenter, randomized controlled study, patients with PersAF (≥7 days and <12 months) despite ADT were prospectively randomized 1:1 to PVI with ADT continued versus discontinued beyond the blanking period (ADT ON versus ADT OFF). Standardized catheter ablation was performed aiming for durable isolation with stable, contiguous, and optimized radio frequency applications encircling the pulmonary veins (CLOSE protocol). Clinical visits and 1-to-7-day Holter were performed at 3, 6, and 12 months. The primary end point was any documented atrial tachyarrhythmia lasting >30 seconds beyond 3 months. Prospectively defined secondary end points included repeat ablations, unscheduled arrhythmia-related visits, and quality of life among groups. RESULTS: Of 200 PersAF patients, 98 were assigned to ADT OFF and 102 to ADT ON. The longest atrial fibrillation episode qualifying for PersAF was 28 (10-90) versus 30 (11-90) days. Clinical characteristics and procedural characteristics were similar. Recurrence of atrial tachyarrhythmia was comparable in both groups (20% OFF versus 21.2% ON). No differences were observed in repeat ablations and unscheduled arrhythmia-related visits. Marked improvement in quality of life was observed in both groups. CONCLUSIONS: In patients with PersAF, there is no benefit in continuing previously ineffective ADT beyond the blanking period after catheter ablation. The high success rate of PVI-only might be explained by the high rate of durable isolation after optimized PVI and the early stage of PersAF (POWDER-AF2). REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03437356.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Humans , Anti-Arrhythmia Agents/adverse effects , Atrial Fibrillation/diagnosis , Atrial Fibrillation/drug therapy , Atrial Fibrillation/surgery , Catheter Ablation/adverse effects , Catheter Ablation/methods , Furylfuramide , Powders/therapeutic use , Pulmonary Veins/surgery , Quality of Life , Recurrence , Tachycardia , Treatment Outcome , Prospective StudiesABSTRACT
AIMS: The aim of our study was to analyse the response to short-coupled atrial extrastimuli to identify areas of hidden slow conduction (HSC) and their relationship with the atrial fibrillation (AF) phenotype. METHODS AND RESULTS: Twenty consecutive patients with paroxysmal AF and persistent AF (10:10) underwent the first pulmonary vein isolation procedure. Triple short-coupled extrastimuli were delivered in sinus rhythm (SR), and the evoked response was analysed: sites exhibiting double or highly fragmented electrograms (EGM) were defined as positive for HSC (HSC+). The delta of the duration of the bipolar EGM was analysed, and bipolar EGM duration maps were built. High-density maps were acquired using a multipolar catheter during AF, SR, and paced rhythm. Spatial co-localization of HSC+ and complex fractionated atrial EGMs (CFAE) during AF was evaluated. Persistent AF showed a higher number and percentage of HSC+ than paroxysmal AF (13.9% vs. 3.3%, P < 0.001). The delta of EGM duration was 53 ± 22â ms for HSC+ compared with 13 ± 11 (10)â ms in sites with negative HSC (HSC-) (P < 0.001). The number and density of HSC+ were lower than CFAE during AF (19 vs. 56 per map, P < 0.001). The reproducibility and distribution of HSC+ in repeated maps were superior to CFAE (P = 0.19 vs. P < 0.001). Sites with negative and positive responses showed a similar bipolar voltage in the preceding sinus beat (1.65 ± 1.34 and 1.48 ± 1.47â mV, P = 0.12). CONCLUSION: Functional mapping identifies more discrete and reproducible abnormal substrates than mapping during AF. The HSC+ sites in response to triple extrastimuli are more frequent in persistent AF than in paroxysmal AF.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Humans , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Reproducibility of Results , Electrophysiologic Techniques, Cardiac/methods , Heart Rate , Heart AtriaABSTRACT
Background: Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption. Methods: Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre. Results: Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed. Conclusions: LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA. (AU)
Introducción: La anticoagulación oral en la fibrilación auricular no valvular se asocia a un incremento del riesgo de sangrado, especialmente gastrointestinal, lo que conlleva la retirada del tratamiento hasta en el 50% de los pacientes e implica un mayor riesgo de padecer un evento embólico. El cierre de la orejuela izquierda (COI) puede ser una alternativa a la anticoagulación crónica. Nuestro objetivo es describir el impacto del COI en pacientes con sangrado gastrointestinal (SGI) o anemia crónica ferropénica (ACF) en el consumo de recursos sanitarios. Métodos: Estudio observacional retrospectivo de pacientes sometidos a COI por SGI o ACF. Resultados: Diecinueve pacientes con una mediana de edad de 74años y una mediana del índice de Charlson de 6puntos fueron incluidos en el estudio. Las angiodisplasias fueron la causa más frecuente de SGI o ACF. La tasa de éxito técnico del COI fue del 100%, con una duración mediana del tratamiento anticoagulante y antiagregante de 92días. Tras un año del COI, se observó una mejoría significativa del valor mínimo de hemoglobina, así como una reducción en el número de transfusiones de concentrados de hematíes, en la necesidad de hospitalización por SGI o ACF y en el número de endoscopias. Un paciente falleció debido a un tromboembolismo pulmonar. Ningún paciente falleció por SGI. Conclusiones: El COI parece una alternativa segura y efectiva a la anticoagulación en pacientes con SGI o ACF. (AU)
Subject(s)
Humans , Male , Female , Aged , Aged, 80 and over , Atrial Fibrillation , Gastrointestinal Hemorrhage , Anemia, Iron-Deficiency , Retrospective Studies , Epidemiology, Descriptive , AnticoagulantsABSTRACT
Over the last decades, cardiac electronic implantable devices (CEID) have incorporated a myriad of technological capabilities that are not conveniently inferred by using the conventional ICHD and NBG coding systems. We propose a new coding system (i.e., the C-ARL-A coding system) aimed at overcoming this important limitation.
Subject(s)
Defibrillators, Implantable , Pacemaker, Artificial , HumansABSTRACT
BACKGROUND: Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption. METHODS: Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre. RESULTS: Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed. CONCLUSIONS: LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA.
Subject(s)
Atrial Appendage , Atrial Fibrillation , Stroke , Humans , Aged , Atrial Fibrillation/complications , Stroke/complications , Atrial Appendage/surgery , Retrospective Studies , Treatment Outcome , Anticoagulants/adverse effects , Gastrointestinal Hemorrhage/complicationsABSTRACT
BACKGROUND: New tools are needed to improve ventricular tachycardia (VT) substrate characterization and optimize outcomes. LI provides biophysical tissue characterization. OBJECTIVES: The purpose of this study was to test local impedance (LI)-based mapping to predict critical ventricular tachycardia components after myocardial infarction (MI). METHODS: One month after a nonreperfused anterior MI, endo-epicardial high-density electroanatomic mapping and endocardial LI mapping were performed in 23 Landrace Large X White pigs. LI thresholds were set using the blood pool value to define a 10 Ω range: low (
Subject(s)
Myocardial Infarction , Tachycardia, Ventricular , Animals , Swine , Electric Impedance , Myocardial Infarction/complications , Epicardial Mapping , EndocardiumABSTRACT
BACKGROUND: Adequate synchronization between the passive ("E") and active ("a") left ventricular (LV) diastolic filling contributes to the efficiency of the heartbeat. E/a superposition in dual-chamber pacemaker (PM) recipients is an under-recognized phenomenon that may be corrected by shortening the atrio-ventricular interval (AVI). We aimed at establishing the prevalence of E/a superposition in PM patients and to analyze the clinical, echocardiographic, and biological impact of AVI shortening. METHODS: Seventy patients with dual-chamber PMs (74 ± 8 years old, 12 women) were consecutively enrolled in this study. Patients with baseline E/a superposition were crossed over from default to manually shortened AVI or vice versa in a case-control fashion (intervention group). Patients without baseline E/a superposition (controls) served as a reference for a descriptive comparison with the intervention group. RESULTS: Thirty-three patients had E/a superposition after PM implantation (47%). Controls (n = 37) had higher LV ejection fraction (59 ± 8% vs. 53 ± 10%, p = 0.048) and lower levels of high sensitive troponin T and ST2 (p < 0.05) than intervention group patients. The AVI was shortened at 48 ± 9 ms in order to ensure adequate E/a separation. The walked distance increased from 75 ± 17 to 78 ± 10% (p = 0.049) and the Euro-QoL score from 0.50 ± 0.27 to 0.63 ± 0.19 (p = 0.011) with short AVI. CONCLUSIONS: E/a superposition occurs in approximately half of dual-chamber PM recipients and is associated with reduced LV function and increased myocardial injury biomarkers. AVI shortening produces a modest but significant effect in functional capacity and quality of life.
Subject(s)
Pacemaker, Artificial , Quality of Life , Humans , Female , Aged , Aged, 80 and over , Cardiac Pacing, Artificial , Diastole , Ventricular Function, LeftABSTRACT
Objective: To assess the arrhythmic safety profile of the adipose graft transposition procedure (AGTP) and its electrophysiological effects on post-myocardial infarction (MI) scar. Background: Myocardial repair is a promising treatment for patients with MI. The AGTP is a cardiac reparative therapy that reduces infarct size and improves cardiac function. The impact of AGTP on arrhythmogenesis has not been addressed. Methods: MI was induced in 20 swine. Contrast-enhanced magnetic resonance (ce-MRI), electrophysiological study (EPS), and left-ventricular endocardial high-density mapping were performed 15 days post-MI. Animals were randomized 1:1 to AGTP or sham-surgery group and monitored with ECG-Holter. Repeat EPS, endocardial mapping, and ce-MRI were performed 30 days post-intervention. Myocardial SERCA2, Connexin-43 (Cx43), Ryanodine receptor-2 (RyR2), and cardiac troponin-I (cTnI) gene and protein expression were evaluated. Results: The AGTP group showed a significant reduction of the total infarct scar, border zone and dense scar mass by ce-MRI (p = 0.04), and a decreased total scar and border zone area in bipolar voltage mapping (p < 0.001). AGTP treatment significantly reduced the area of very-slow conduction velocity (<0.2 m/s) (p = 0.002), the number of deceleration zones (p = 0.029), and the area of fractionated electrograms (p = 0.005). No differences were detected in number of induced or spontaneous ventricular arrhythmias at EPS and Holter-monitoring. SERCA2, Cx43, and RyR2 gene expression were decreased in the infarct core of AGTP-treated animals (p = 0.021, p = 0.018, p = 0.051, respectively). Conclusion: AGTP is a safe reparative therapy in terms of arrhythmic risk and provides additional protective effect against adverse electrophysiological remodeling in ischemic heart disease.
ABSTRACT
Inappropriate sinus tachycardia (IST) is a common observation in patients with post-COVID-19 syndrome (PCS) but has not yet been fully described to date. To investigate the prevalence and the mechanisms underlying IST in a prospective population of PCS patients. Consecutive patients admitted to the PCS Unit between June and December 2020 with a resting sinus rhythm rate ≥ 100 bpm were prospectively enrolled in this study and further examined by an orthostatic test, 2D echocardiography, 24-h ECG monitoring (heart rate variability was a surrogate for cardiac autonomic activity), quality-of-life and exercise capacity testing, and blood sampling. To assess cardiac autonomic function, a 2:1:1 comparative sub-analysis was conducted against both fully recovered patients with previous SARS-CoV-2 infection and individuals without prior SARS-CoV-2 infection. Among 200 PCS patients, 40 (20%) fulfilled the diagnostic criteria for IST (average age of 40.1 ± 10 years, 85% women, 83% mild COVID-19). No underlying structural heart disease, pro-inflammatory state, myocyte injury, or hypoxia were identified. IST was accompanied by a decrease in most heart rate variability parameters, especially those related to cardiovagal tone: pNN50 (cases 3.2 ± 3 vs. recovered 10.5 ± 8 vs. non-infected 17.3 ± 10; p < 0.001) and HF band (246 ± 179 vs. 463 ± 295 vs. 1048 ± 570, respectively; p < 0.001). IST is prevalent condition among PCS patients. Cardiac autonomic nervous system imbalance with decreased parasympathetic activity may explain this phenomenon.
Subject(s)
COVID-19/complications , Tachycardia, Sinus/etiology , Adult , COVID-19/diagnosis , COVID-19/pathology , COVID-19/physiopathology , Female , Heart Rate , Humans , Male , Middle Aged , Myocardium/pathology , Prevalence , Prospective Studies , SARS-CoV-2/isolation & purification , Tachycardia, Sinus/diagnosis , Tachycardia, Sinus/pathology , Tachycardia, Sinus/physiopathology , Post-Acute COVID-19 SyndromeABSTRACT
BACKGROUND: Catheter ablation of accessory pathways (AP) with bidirectional conduction may be challenging due to issues related to anatomical course or location. OBJECTIVE: We describe an alternative electro-anatomical mapping technique which aims at depicting the entire anatomic course of the AP from the atrial toward the ventricular insertion in order to guide catheter ablation. METHODS: Twenty consecutive patients with confirmed bidirectional AP conduction and at least one previous ablation procedure or para-Hisian location were included. 3-D electro-anatomical mapping was used to depict the merged 10-ms isochrone area of maximum early activation of both the ventricular and atrial signals during sinus rhythm and ventricular pacing/orthodromic tachycardia, respectively. Catheter ablation was performed within the depicted earliest isochrone area. RESULTS: Acute bidirectional AP conduction block was achieved in all patients 4.2 ± 1.7 s after the first radiofrequency energy pulse was delivered, without reconnection during a 30 ± 10 min post-ablation observation time. No procedural complications were seen. After a mean follow-up period of 9 ± 7 months (range 3 to 16), no recurrences were documented. CONCLUSION: This merged two-way mapping technique is a safe, efficient, and effective technique for ablation of APs with bidirectional conduction.
Subject(s)
Accessory Atrioventricular Bundle , Catheter Ablation , Accessory Atrioventricular Bundle/surgery , Catheter Ablation/methods , Electrocardiography , Heart Atria/diagnostic imaging , Heart Atria/surgery , Heart Rate , HumansABSTRACT
Background: Atrial fibrillation (AF) ablation strategy is associated with a non-negligible risk of complications and often requires repeat procedures (AF ablation track), implying repetitive exposure to procedural risk. Objective: The purpose of this study was to develop and validate a model to estimate individualized cumulative risk of complications in patients undergoing the AF ablation track (Atrial Fibrillation TRAck Complication risK [AF-TRACK] calculator). Methods: The model was derived from a multicenter cohort including 3762 AF ablation procedures in 2943 patients. A first regression model was fitted to predict the propensity for repeat ablation. The AF-TRACK calculator computed the risk of AF ablation track complications, considering the propensity for repeat ablation. Internal (cross-validation) and external (independent cohort) validation were assessed for discrimination capacity (area under the curve [AUC]) and goodness of fit (Hosmer-Lemeshow [HL] test). Results: Complications (N = 111) occurred in 3.7% of patients (2.9% of procedures). Predictors included female sex, heart failure, sleep apnea syndrome, and repeat procedures. The model showed fair discrimination capacity to predict complications (AUC 0.61 [0.55-0.67]) and likelihood of repeat procedure (AUC 0.62 [0.60-0.64]), with good calibration (HL χ2 12.5; P = .13). The model maintained adequate discrimination capacity (AUC 0.67 [0.57-0.77]) and calibration (HL χ2 5.6; P = .23) in the external validation cohort. The validated model was used to create the Web-based AF-TRACK calculator. Conclusion: The proposed risk model provides individualized estimates of the cumulative risk of complications of undergoing the AF ablation track. The AF-TRACK calculator is a validated, easy-to-use, Web-based clinical tool to calibrate the risk-to-benefit ratio of this treatment strategy.
ABSTRACT
Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization and cardiovascular drugs, a significant proportion of patients develop pathological left-ventricular remodeling and progressive heart failure following MI. Therefore, new therapeutic options, such as cellular and gene therapies, among others, have been developed to repair and regenerate injured myocardium. In this context, animal models of MI are crucial in exploring the safety and efficacy of these experimental therapies before clinical translation. Large animal models such as swine are preferred over smaller ones due to the high similarity of swine and human hearts in terms of coronary artery anatomy, cardiac kinetics, and the post-MI healing process. Here, we aimed to describe an MI model in pig by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, the coil is deployed at the target branch under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography. This approach is feasible, highly reproducible, and emulates the pathogenesis of human non-revascularized MI, avoiding the traditional open-chest surgery and the subsequent postoperative inflammation. Depending on the time of follow-up, the technique is suitable for acute, sub-acute, or chronic MI models.
Subject(s)
Myocardial Infarction , Animals , Disease Models, Animal , Heart , Humans , Myocardial Infarction/etiology , Myocardial Infarction/pathology , Myocardial Infarction/therapy , Myocardium/pathology , Swine , Ventricular RemodelingABSTRACT
Up to one-third of patients who undergo cardiac resynchronization therapy do not obtain clinical benefit. A systematic approach can identify treatable causes in many nonresponding patients. We present a case of nonresponse to cardiac resynchronization therapy that resolved by ablation of the atrioventricular node in a patient with complete atrioventricular block. (Level of Difficulty: Advanced.).
ABSTRACT
BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICDs) avoid complications secondary to transvenous leads, but inappropriate shocks (ISs) are frequent. Furthermore, IS data from patients with Brugada syndrome (BrS) with an S-ICD are scarce. OBJECTIVE: We aimed to establish the frequency and predictors of IS in this population. METHODS: We analyzed the clinical and electrocardiographic characteristics, automated screening test data, device programming, and IS occurrence in adult patients with BrS with an S-ICD. RESULTS: Thirty-nine patients were enrolled (69% male, mean age at diagnosis 46 ± 13 years, mean age at implantation 48 ± 13 years). During a mean follow-up of 26 ± 21 months, 18% patients experienced IS. Patients with IS were younger at the time of diagnosis (36 ± 8 vs. 48 ± 13 years, p = .018) and S-ICD implantation (38 ± 9 vs. 50 ± 23 years, p = .019) and presented with spontaneous type 1 Brugada electrocardiogram pattern more frequently at diagnosis or during follow-up (71% vs. 25%, p = .018). During automated screening tests, patients with IS showed lower QRS voltage in the primary vector in the supine position (0.58 ± 0.26 vs. 1.10 ± 0.35 mV, p = .011) and lower defibrillator automated screening score in the primary vector in the supine (123 ± 165 vs. 554 ± 390 mV, p = .005) and standing (162 ± 179 vs. 486 ± 388 mV, p = .038) positions. Age at diagnosis was the only independent predictor of IS (hazard ratio = 0.873, 95% confidence interval: 0.767-0.992, p = .037). CONCLUSION: IS was a frequent complication in patients with BrS with an S-ICD. Younger age was independently associated with IS. A more thorough screening process might help prevent IS in this population.