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RATIONALE: Costly proprietary panoramic multielectrode (64-256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fibrillation (PersAF) ablation. However, such approaches target alleged drivers (rotational/focal) regardless of their activation frequency dynamics. OBJECTIVES: To test the hypothesis that stable regions of higher than surrounding instantaneous frequency modulation (iFM) drive PersAF and determine whether rotational activity is specific for such regions. METHODS AND RESULTS: First, novel single-signal algorithms based on instantaneous amplitude modulation (iAM) and iFM to detect rotational-footprints without panoramic multielectrode acquisition systems were tested in 125 optical movies from 5 ex vivo Langendorff-perfused PersAF sheep hearts (sensitivity/specificity, 92.6/97.5%; accuracy, 2.5-mm) and in computer simulations. Then, 16 pigs underwent high-rate atrial pacing to develop PersAF. After a median (interquartile range [IQR]) of 4.4 (IQR, 2.5-9.9) months of high-rate atrial pacing followed by 4.1 (IQR, 2.7-5.4) months of self-sustained PersAF, pigs underwent in vivo high-density electroanatomical atrial mapping (4920 [IQR, 4435-5855] 8-second unipolar signals per map). The first 4 out of 16 pigs were used to adapt ex vivo optical proccessing of iFM/iAM to in vivo electrical signals. In the remaining 12 out of 16 pigs, regions of higher than surrounding average iFM were considered leading-drivers. Two leading-driver + rotational-footprint maps were generated 2.6 (IQR, 2.4-2.9) hours apart to test leading-driver spatiotemporal stability and guide ablation. Leading-driver regions (2.5 [IQR, 2.0-4.0] regions/map) exactly colocalized (95.7%) in the 2 maps, and their ablation terminated PersAF in 92.3% of procedures (radiofrequency until termination, 16.9 [IQR, 9.2-35.8] minutes; until nonsustainability, 20.4 [IQR, 12.8-44.0] minutes). Rotational-footprints were found at every leading-driver region, albeit most (76.8% [IQR, 70.5%-83.6%]) were located outside. Finally, the translational ability of this approach was tested in 3 PersAF redo patients. CONCLUSIONS: Both rotational-footprints and spatiotemporally stable leading-driver regions can be located using iFM/iAM algorithms without panoramic multielectrode acquisition systems. In pigs, ablation of leading-driver regions usually terminates PersAF and prevents its sustainability. Rotational activations are sensitive but not specific to such regions. Single-signal iFM/iAM algorithms could be integrated into conventional electroanatomical mapping systems to improve driver detection accuracy and reduce the cost of patient-tailored/mechanistic approaches.
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Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Mapeamento Potencial de Superfície Corporal/métodos , Ablação por Cateter/métodos , Frequência Cardíaca/fisiologia , Imageamento Tridimensional/métodos , Potenciais de Ação/fisiologia , Adulto , Idoso , Animais , Fibrilação Atrial/diagnóstico por imagem , Feminino , Humanos , Preparação de Coração Isolado/métodos , Masculino , Pessoa de Meia-Idade , Ovinos , SuínosRESUMO
Anatomical-based approaches, targeting either pulmonary vein isolation (PVI) or additional extra PV regions, represent the most commonly used ablation treatments in symptomatic patients with atrial fibrillation (AF) recurrences despite antiarrhythmic drug therapy. PVI remains the main anatomical target during catheter-based AF ablation, with the aid of new technological advances as contact force monitoring to increase safety and effective radiofrequency (RF) lesions. Nowadays, cryoballoon ablation has also achieved the same level of scientific evidence in patients with paroxysmal AF undergoing PVI. In parallel, electrical isolation of extra PV targets has progressively increased, which is associated with a steady increase in complex cases undergoing ablation. Several atrial regions as the left atrial posterior wall, the vein of Marshall, the left atrial appendage, or the coronary sinus have been described in different series as locations potentially involved in AF initiation and maintenance. Targeting these regions may be challenging using conventional point-by-point RF delivery, which has opened new opportunities for coadjuvant alternatives as balloon ablation or selective ethanol injection. Although more extensive ablation may increase intraprocedural AF termination and freedom from arrhythmias during the follow-up, some of the targets to achieve such outcomes are not exempt of potential severe complications. Here, we review and discuss current anatomical approaches and the main ablation technologies to target atrial regions associated with AF initiation and maintenance.
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Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Veias Pulmonares/cirurgia , Procedimentos Cirúrgicos Cardíacos/métodos , Humanos , Resultado do TratamentoRESUMO
AIMS: Atrial electrical remodelling (AER) is a transitional period associated with the progression and long-term maintenance of atrial fibrillation (AF). We aimed to study the progression of AER in individual patients with implantable devices and AF episodes. METHODS AND RESULTS: Observational multicentre study (51 centres) including 4618 patients with implantable cardioverter-defibrillator +/-resynchronization therapy (ICD/CRT-D) and 352 patients (2 centres) with pacemakers (median follow-up: 3.4 years). Atrial activation rate (AAR) was quantified as the frequency of the dominant peak in the signal spectrum of AF episodes with atrial bipolar electrograms. Patients with complete progression of AER, from paroxysmal AF episodes to electrically remodelled persistent AF, were used to depict patient-specific AER slopes. A total of 34 712 AF tracings from 830 patients (87 with pacemakers) were suitable for the study. Complete progression of AER was documented in 216 patients (16 with pacemakers). Patients with persistent AF after completion of AER showed â¼30% faster AAR than patients with paroxysmal AF. The slope of AAR changes during AF progression revealed patient-specific patterns that correlated with the time-to-completion of AER (R2 = 0.85). Pacemaker patients were older than patients with ICD/CRT-Ds (78.3 vs. 67.2 year olds, respectively, P < 0.001) and had a shorter median time-to-completion of AER (24.9 vs. 93.5 days, respectively, P = 0.016). Remote transmissions in patients with ICD/CRT-D devices enabled the estimation of the time-to-completion of AER using the predicted slope of AAR changes from initiation to completion of electrical remodelling (R2 = 0.45). CONCLUSION: The AF progression shows patient-specific patterns of AER, which can be estimated using available remote-monitoring technology.
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Fibrilação Atrial , Remodelamento Atrial , Desfibriladores Implantáveis , Marca-Passo Artificial , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/terapia , Pré-Escolar , HumanosRESUMO
AIMS: Myocardial infarction (MI) alters cardiac fibre organization with unknown consequences on ventricular arrhythmia. We used diffusion tensor imaging (DTI) of three-dimensional (3D) cardiac fibres and scar reconstructions to identify the main parameters associated with ventricular arrhythmia inducibility and ventricular tachycardia (VT) features after MI. METHODS AND RESULTS: Twelve pigs with established MI and three controls underwent invasive electrophysiological characterization of ventricular arrhythmia inducibility and VT features. Animal-specific 3D scar and myocardial fibre distribution were obtained from ex vivo high-resolution contrast-enhanced T1 mapping and DTI sequences. Diffusion tensor imaging-derived parameters significantly different between healthy and scarring myocardium, scar volumes, and left ventricular ejection fraction (LVEF) were included for arrhythmia risk stratification and correlation analyses with VT features. Ventricular fibrillation (VF) was the only inducible arrhythmia in 4 out of 12 infarcted pigs and all controls. Ventricular tachycardia was also inducible in the remaining eight pigs during programmed ventricular stimulation. A DTI-based 3D fibre disorganization index (FDI) showed higher disorganization within dense scar regions of VF-only inducible pigs compared with VT inducible animals (FDI: 0.36; 0.36-0.37 vs. 0.32; 0.26-0.33, respectively, P = 0.0485). Ventricular fibrillation induction required lower programmed stimulation aggressiveness in VF-only inducible pigs than VT inducible and control animals. Neither LVEF nor scar volumes differentiated between VF and VT inducible animals. Re-entrant VT circuits were localized within areas of highly disorganized fibres. Moreover, the FDI within heterogeneous scar regions was associated with the median VT cycle length per animal (R2 = 0.5320). CONCLUSION: The amount of scar-related cardiac fibre disorganization in DTI sequences is a promising approach for ventricular arrhythmia stratification after MI.
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Cicatriz , Imagem de Tensor de Difusão/métodos , Coração/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Infarto do Miocárdio/complicações , Miocárdio/patologia , Taquicardia Ventricular , Animais , Cicatriz/diagnóstico por imagem , Cicatriz/patologia , Cicatriz/fisiopatologia , Medição de Risco , Suínos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologiaRESUMO
AIMS: We aimed to study the differences in biventricular scar characterization using bipolar voltage mapping compared with state-of-the-art in vivo delayed gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging and ex vivo T1 mapping. METHODS AND RESULTS: Ten pigs with established myocardial infarction (MI) underwent in vivo scar characterization using LGE-CMR imaging and high-density voltage mapping of both ventricles using a 3.5-mm tip catheter. Ex vivo post-contrast T1 mapping provided a high-resolution reference. Voltage maps were registered onto the left and right ventricular (LV and RV) endocardium, and epicardium of CMR-based geometries to compare voltage-derived scars with surface-projected 3D scars. Voltage-derived scar tissue of the LV endocardium and the epicardium resembled surface projections of 3D in vivo and ex vivo CMR-derived scars using 1-mm of surface projection distance. The thinner wall of the RV was especially sensitive to lower resolution in vivo LGE-CMR images, in which differences between normalized low bipolar voltage areas and CMR-derived scar areas did not decrease below a median of 8.84% [interquartile range (IQR) (3.58, 12.70%)]. Overall, voltage-derived scars and surface scar projections from in vivo LGE-CMR sequences showed larger normalized scar areas than high-resolution ex vivo images [12.87% (4.59, 27.15%), 18.51% (11.25, 24.61%), and 9.30% (3.84, 19.59%), respectively], despite having used optimized surface projection distances. Importantly, 43.02% (36.54, 48.72%) of voltage-derived scar areas from the LV endocardium were classified as non-enhanced healthy myocardium using ex vivo CMR imaging. CONCLUSION: In vivo LGE-CMR sequences and high-density voltage mapping using a conventional linear catheter fail to provide accurate characterization of post-MI scar, limiting the specificity of voltage-based strategies and imaging-guided procedures.
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Potenciais de Ação , Arritmias Cardíacas/diagnóstico , Cicatriz/diagnóstico por imagem , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Imageamento por Ressonância Magnética , Infarto do Miocárdio/diagnóstico por imagem , Miocárdio/patologia , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Cicatriz/etiologia , Cicatriz/patologia , Cicatriz/fisiopatologia , Meios de Contraste/administração & dosagem , Modelos Animais de Doenças , Frequência Cardíaca , Masculino , Meglumina/administração & dosagem , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Compostos Organometálicos/administração & dosagem , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sus scrofaRESUMO
BACKGROUND: Catheter ablation (CA) is a highly effective therapy for the treatment of paroxysmal atrial fibrillation (AF) when compared with antiarrhythmic drug therapy (ADT). No randomized studies have compared the two strategies in persistent AF. The present randomized trial aimed to compare the effectiveness of CA vs. ADT in treating persistent AF. METHODS AND RESULTS: Patients with persistent AF were randomly assigned to CA or ADT (excluding patients with long-standing persistent AF). Primary endpoint at 12-month follow-up was defined as any episode of AF or atrial flutter lasting >24 h that occurred after a 3-month blanking period. Secondary endpoints were any atrial tachyarrhythmia lasting >30 s, hospitalization, and electrical cardioversion. In total, 146 patients were included (aged 55 ± 9 years, 77% male). The ADT group received class Ic (43.8%) or class III drugs (56.3%). In an intention-to-treat analysis, 69 of 98 patients (70.4%) in the CA group and 21 of 48 patients (43.7%) in the ADT group were free of the primary endpoint (P = 0.002), implying an absolute risk difference of 26.6% (95% CI 10.0-43.3) in favour of CA. The proportion of patients free of any recurrence (>30 s) was higher in the CA group than in the ADT group (60.2 vs. 29.2%; P < 0.001) and cardioversion was less frequent (34.7 vs. 50%, respectively; P = 0.018). CONCLUSION: Catheter ablation is superior to medical therapy for the maintenance of sinus rhythm in patients with persistent AF at 12-month follow-up. CLINICAL TRIAL REGISTRATION INFORMATION: NCT00863213 (http://clinicaltrials.gov/ct2/show/NCT00863213).
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Antiarrítmicos/uso terapêutico , Fibrilação Atrial/terapia , Ablação por Cateter/métodos , Ablação por Cateter/efeitos adversos , Doença Crônica , Término Precoce de Ensaios Clínicos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Resultado do TratamentoRESUMO
INTRODUCTION: New generation open-irrigated catheters aim to improve irrigation efficiency. This may change lesion patterns, challenging operators. Indeed, safety issues have recently arisen. We aimed to experimentally assess 4 open-irrigated catheters, comparing lesion size, safety, and heat transfer. METHODS: The thigh lesion model was employed in 6 anesthetized pigs to assess the morphology of perpendicular and tangential lesions (n = 140) created by the newer catheters ThermoCool® SF, CoolFlex™, and Blazer™ Open-Irrigated, and the standard ThermoCool®, at a constant power of 30 W (60 seconds). To evaluate the propensity for deep-tissue overheating, a set of 120 applications were performed at 50 W (180 seconds) comparing pop rates. Thermal assessment of the lesion generation process (20 W, 60 seconds, n = 32) was performed with an infrared camera on bovine ventricular tissue. RESULTS: At 30 W, the newer catheters showed lower temperature readings compared with the ThermoCool®. No major efficacy or safety differences were found at tangential applications; however, at perpendicular applications: (1) the SF at 17 mL/min better preserved the superficial layers and focused its maximum thermal effect deeper, but at recommended flow rates (8 mL/min) it generated the largest superficial lesions; (2) CoolFlex™ created smaller lesions than SF and readily induced steam pops at 50 W without temperature control; and (3) no major differences were found comparing Blazer™ Open-Irrigated and ThermoCool®. CONCLUSIONS: The lower temperature readings in the newer catheters make them more prone to deliver the maximum programmed power. Under experimental conditions, the SF catheter focuses its maximum effect deeper and the CoolFlex™ can be more prone to induce steam pops at high power settings.
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Temperatura Corporal/fisiologia , Cateteres Cardíacos , Procedimentos Cirúrgicos Cardíacos/instrumentação , Ablação por Cateter/instrumentação , Coração/fisiologia , Irrigação Terapêutica/instrumentação , Animais , Procedimentos Cirúrgicos Cardíacos/métodos , Ablação por Cateter/métodos , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Suínos , Irrigação Terapêutica/métodos , Resultado do TratamentoRESUMO
Atrial fibrillation (AF) causes progressive structural and electrical changes in the atria that can be summarized within the general concept of atrial remodeling. In parallel, other clinical characteristics and comorbidities may also affect atrial tissue properties and make the atria susceptible to AF initiation and its long-term persistence. Overall, pathological atrial changes lead to atrial cardiomyopathy with important implications for rhythm control. Although there is general agreement on the role of the atrial substrate for successful rhythm control in AF, the current classification oversimplifies clinical management. The classification uses temporal criteria and does not establish a well-defined strategy to characterize the individual-specific degree of atrial cardiomyopathy. Better characterization of atrial cardiomyopathy may improve the decision-making process on the most appropriate therapeutic option. We review current scientific evidence and propose a practical characterization of the atrial substrate based on 3 evaluation steps starting with a clinical evaluation (step 1), then assess outpatient complementary data (step 2), and finally include information from advanced diagnostic tools (step 3). The information from each of the steps or a combination thereof can be used to classify AF patients in 4 stages of atrial cardiomyopathy, which we also use to estimate the success on effective rhythm control.
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Fibrilação Atrial , Cardiomiopatias , Átrios do Coração , Humanos , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/complicações , Fibrilação Atrial/terapia , Fibrilação Atrial/etiologia , Cardiomiopatias/diagnóstico , Cardiomiopatias/fisiopatologia , Cardiomiopatias/etiologia , Cardiomiopatias/complicações , Átrios do Coração/fisiopatologia , Remodelamento Atrial/fisiologiaRESUMO
INTRODUCTION AND OBJECTIVES: The multiparametric implantable cardioverter-defibrillator HeartLogic index has proven to be a sensitive and timely predictor of impending heart failure (HF) decompensation. We evaluated the impact of a standardized follow-up protocol implemented by nursing staff and based on remote management of alerts. METHODS: The algorithm was activated in HF patients at 19 Spanish centers. Transmitted data were analyzed remotely, and patients were contacted by telephone if alerts were issued. Clinical actions were implemented remotely or through outpatient visits. The primary endpoint consisted of HF hospitalizations or death. Secondary endpoints were HF outpatient visits. We compared the 12-month periods before and after the adoption of the protocol. RESULTS: We analyzed 392 patients (aged 69±10 years, 76% male, 50% ischemic cardiomyopathy) with implantable cardioverter-defibrillators (20%) or cardiac resynchronization therapy defibrillators (80%). The primary endpoint occurred 151 times in 86 (22%) patients during the 12 months before the adoption of the protocol, and 69 times in 45 (11%) patients (P<.001) during the 12 months after its adoption. The mean number of hospitalizations per patient was 0.39±0.89 pre- and 0.18±0.57 postadoption (P<.001). There were 185 outpatient visits for HF in 96 (24%) patients before adoption and 64 in 48 (12%) patients after adoption (P<.001). The mean number of visits per patient was 0.47±1.11 pre- and 0.16±0.51 postadoption (P<.001). CONCLUSIONS: A standardized follow-up protocol based on remote management of HeartLogic alerts enabled effective remote management of HF patients. After its adoption, we observed a significant reduction in HF hospitalizations and outpatient visits.
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BACKGROUND: Electrical isolation of pulmonary veins (PV) with high-power short-duration (HPSD) radiofrequency application (RFa) may reduce the duration of atrial fibrillation (AF) ablation, without compromising the procedural efficacy and safety in comparison with the conventional approach. This hypothesis has been generated in several observational studies; the POWER FAST III will test it in a randomized multicenter clinical trial. METHODS: It is a multicenter randomized, open-label and non-inferiority clinical trial with two parallel groups. AF ablation using 70 W and 9-10 s RFa is compared with the conventional technique using 25-40 W RFa guided by numerical lesion indexes. The main efficacy objective is the incidence of atrial arrhythmia recurrences electrocardiographically documented during 1-year follow-up. The main safety objective is the incidence of endoscopically detected esophageal thermal lesions (EDEL). This trial includes a substudy of incidence of asymptomatic cerebral lesions detected by magnetic resonance imaging (MRI) after ablation. RESULTS: A randomized clinical trial compares for the first time high-power short-duration and conventional ablation in order to obtain data about the efficacy and safety of the high-power technique in an adequate methodological context. CONCLUSIONS: The results of the POWER FAST III could support the use of the high-power short-duration ablation in clinical practice. REGISTRATION: ClinicalTrials.gov: NTC04153747.
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Electromechanical characterization during atrial fibrillation (AF) remains a significant gap in the understanding of AF-related atrial myopathy. This study reports mechanistic insights into the electromechanical remodeling process associated with AF progression and further demonstrates its prognostic value in the clinic. In pigs, sequential electromechanical assessment during AF progression shows a progressive decrease in mechanical activity and early dissociation from its electrical counterpart. Atrial tissue samples from animals with AF reveal an abnormal increase in cardiomyocytes death and alterations in calcium handling proteins. High-throughput quantitative proteomics and immunoblotting analyses at different stages of AF progression identify downregulation of contractile proteins and progressive increase in atrial fibrosis. Moreover, advanced optical mapping techniques, applied to whole heart preparations during AF, demonstrate that AF-related remodeling decreases the frequency threshold for dissociation between transmembrane voltage signals and intracellular calcium transients compared to healthy controls. Single cell simulations of human atrial cardiomyocytes also confirm the experimental results. In patients, non-invasive assessment of the atrial electromechanical relationship further demonstrate that atrial electromechanical dissociation is an early prognostic indicator for acute and long-term rhythm control.
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Fibrilação Atrial , Remodelamento Atrial , Doenças Musculares , Humanos , Animais , Suínos , Prognóstico , Cálcio/metabolismo , Átrios do Coração/metabolismoRESUMO
INTRODUCTION AND OBJECTIVES: HeartLogic is a multiparametric algorithm incorporated into implantable cardioverter-defibrillators (ICD). The associated alerts predict impending heart failure (HF) decompensations. Our objective was to analyze the association between alerts and clinical events and to describe the implementation of a protocol for remote management in a multicenter registry. METHODS: We evaluated study phase 1 (the investigators were blinded to the alert state) and phases 2 and 3 (after HeartLogic activation, managed as per local practice and with a standardized protocol, respectively). RESULTS: We included 288 patients from 15 centers. In phase 1, the median observation period was 10 months and there were 73 alerts (0.72 alerts/patient-y), with 8 hospitalizations and 2 emergency room admissions for HF (0.10 events/patient-y). There were no HF hospitalizations outside the alert period. In the active phases, the median follow-up was 16 (95%CI, 15-22) months and there were 277 alerts (0.89 alerts/patient-y); 33 were associated with HF hospitalizations or HF death (n=6), 46 with minor decompensations, and 78 with other events. The unexplained alert rate was 0.39 alerts/patient-y. Outside the alert state, there was only 1 HF hospitalization and 1 minor HF decompensation. Most alerts (82% in phase 2 and 81% in phase 3; P=.861) were remotely managed. The median NT-proBNP value was higher within than outside the alert state (7378 vs 1210 pg/mL; P <.001). CONCLUSIONS: The HeartLogic index was frequently associated with HF-related events and other clinically relevant situations, with a low rate of unexplained events. A standardized protocol allowed alerts to be safely and remotely detected and appropriate action to be taken on them.
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Desfibriladores Implantáveis , Insuficiência Cardíaca , Algoritmos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Hospitalização , Humanos , Sistema de RegistrosRESUMO
UNLABELLED: INTRODUCTION: Some observations support the existence of epicardial connections (ECs) between ipsilateral pulmonary veins (vein to vein ECs [VVECs]), and we have observed venoatrial ECs inserted at distance from the pulmonary vein ostium (vein to atrium ECs [VAECs]). Our aim was to determine the prevalence of ECs and their relevance for pulmonary vein isolation. METHODS AND RESULTS: We studied 100 consecutive patients with drug-refractory atrial fibrillation who underwent ostial pulmonary vein isolation by cooled radiofrequency catheter ablation. A VVEC was identified if pulmonary vein pacing activated the ipsilateral vein before the atrium, requiring ablation of both venous ostia to isolate either pulmonary vein. A VAEC was identified if pacing produced atrial breakthrough located at distance from the venous ostium, requiring extraostial ablation to isolate the pulmonary vein. Patients with ECs (20%) were younger (P = 0.02) and had a higher prevalence of structural heart disease (P = 0.01) than patients without ECs. VVECs and VAECs were identified in 32 pulmonary veins (10%) and VAECs in 10 veins (3%). Veins with ECs had a higher rate of early recurrence of conduction following isolation (29% vs 11%; P = 0.01). CONCLUSION: Twenty percent of patients with atrial fibrillation had ECs resistant to ostial ablation in one or more pulmonary veins. Isolating veins with ECs may require a different ablation approach. These connections are associated with an increased rate of early recurrence of conduction. (J Cardiovasc Electrophysiol, Vol. 22, pp. 149-159, February 2011).
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Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Sistema de Condução Cardíaco/cirurgia , Pericárdio/fisiopatologia , Veias Pulmonares/fisiopatologia , Mapeamento Potencial de Superfície Corporal , Feminino , Átrios do Coração/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Pericárdio/cirurgia , Veias Pulmonares/cirurgia , Resultado do TratamentoRESUMO
Catheter ablation remains the most effective and relatively minimally invasive therapy for rhythm control in patients with AF. Ablation has consistently shown a reduction of arrhythmia-related symptoms and significant improvement in patients' quality of life compared with medical treatment. The ablation strategy relies on a well-established anatomical approach of effective pulmonary vein isolation. Additional anatomical targets have been reported with the aim of increasing procedure success in complex substrates. However, larger ablated areas with uncertainty of targeting relevant regions for AF initiation or maintenance are not exempt from the potential risk of complications and pro-arrhythmia. Recent developments in mapping tools and computational methods for advanced signal processing during AF have reported novel strategies to identify atrial regions associated with AF maintenance. These novel tools - although mainly limited to research series - represent a significant step forward towards the understanding of complex patterns of propagation during AF and the potential achievement of patient-tailored AF ablation strategies for the near future.
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INTRODUCTION: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a severe respiratory disease with a 3% global mortality. In the absence of effective treatment, controlling of risk factors that predispose to severe disease is essential to reduce coronavirus disease 2019 (COVID-19) mortality. Large observational studies suggest that exercise can reduce the risk of all-cause and disease-specific mortality. The aim of this study was to analyze the influence of the baseline physical activity level on COVID-19 mortality METHODS: This is a retrospective cohort study that included patients between 18 and 70 years old, diagnosed with COVID-19 and hospitalized in our center between February 15 and April 15, 2020. After discharge all the patients included in the study were contacted by telephone. Baseline physical activity level was estimated using the Rapid Assessment of Physical Activity Scale questionnaire and patients were divided into two groups for comparison: sedentary patients (group 1) and active patients (group 2). RESULTS: During the study period 552 patients were admitted to our hospital and met the inclusion criteria. Global mortality in group 1 was significantly higher than in group 2 (13.8% vs 1.8%; p < 0.001). Patients with a sedentary lifestyle had increased COVID-19 mortality independently of other risk factors previously described (hazard ratio 5.91 (1.80-19.41); p = 0.003). CONCLUSION: A baseline sedentary lifestyle increases the mortality of hospitalized patients with COVID-19. This finding may be of great utility in the prevention of severe COVID-19 disease.
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Delayed gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging requires novel and time-efficient approaches to characterize the myocardial substrate associated with ventricular arrhythmia in patients with ischemic cardiomyopathy. Using a translational approach in pigs and patients with established myocardial infarction, we tested and validated a novel 3D methodology to assess ventricular scar using custom transmural criteria and a semiautomatic approach to obtain transmural scar maps in ventricular models reconstructed from both 3D-acquired and 3D-upsampled-2D-acquired LGE-CMR images. The results showed that 3D-upsampled models from 2D LGE-CMR images provided a time-efficient alternative to 3D-acquired sequences to assess the myocardial substrate associated with ischemic cardiomyopathy. Scar assessment from 2D-LGE-CMR sequences using 3D-upsampled models was superior to conventional 2D assessment to identify scar sizes associated with the cycle length of spontaneous ventricular tachycardia episodes and long-term ventricular tachycardia recurrences after catheter ablation. This novel methodology may represent an efficient approach in clinical practice after manual or automatic segmentation of myocardial borders in a small number of conventional 2D LGE-CMR slices and automatic scar detection.
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Cardiomiopatias/diagnóstico por imagem , Cicatriz/patologia , Taquicardia Ventricular/diagnóstico por imagem , Idoso , Animais , Arritmias Cardíacas/patologia , Cardiomiopatias/metabolismo , Cicatriz/diagnóstico por imagem , Biologia Computacional/métodos , Meios de Contraste , Feminino , Gadolínio/farmacologia , Ventrículos do Coração/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/patologia , Miocárdio/patologia , Recidiva , Suínos , Taquicardia Ventricular/fisiopatologiaRESUMO
AIMS: Whether skeletal myoblast (SM) implants are proarrhythmic is still controversial due to conflicting pre-clinical and clinical data. We hypothesized that if SM implants are arrhythmogenic, they will facilitate the induction of ventricular tachyarrhythmias by promoting heterogeneous propagation of activation wavefronts. METHODS: Skeletal myoblast cells were harvested from 10 pigs. A month later, 125 ± 37 × 10(6) cells were subepicardially injected in an area of â¼2 cm(2) at the anterolateral aspect of the left ventricle. Four weeks later, a ventricular stimulation protocol was conducted. Once explanted, epicardial wavefronts over SM and adjacent control areas were optically mapped. Eight saline-injected animals were used as controls. To compare with clear arrhythmogenic substrates, propagation patterns were also evaluated in infarcted hearts and on a SM-implanted heart following amiodarone infusion. RESULTS: In SM hearts, fibrosis and differentiated SM cells were consistently found and no tachyarrhythmias were induced. Wavefronts propagated homogeneously over SM and adjacent areas, with no late activation zones, as opposed to the infarcted hearts. The time required for the wavefronts to depolarize both areas were similar, becoming only slightly longer at SM areas after an extra-stimulus (P = 0.025). Conduction velocities and APD(90) were also similar. Saline hearts showed similar results. The extent of the conduction delay was not related to the number of injected SM cells. CONCLUSION: In normal swine hearts, myoblast implants promote localized fibrosis and slightly retard epicardial wavefront propagation only after extra-stimuli. However, SM implants are not associated with local re-entry and do not facilitate ventricular tachyarrhythmias in the whole normal heart.
Assuntos
Ventrículos do Coração/fisiopatologia , Mioblastos Esqueléticos/transplante , Infarto do Miocárdio/cirurgia , Taquicardia/fisiopatologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Amiodarona/farmacologia , Animais , Feminino , Ventrículos do Coração/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Infarto do Miocárdio/fisiopatologia , Suínos , Taquicardia/etiologia , Taquicardia/patologiaRESUMO
BACKGROUND: Atrial fibrillation (AF) is a growing health burden, and pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) represents an attractive therapeutic option. Sex-specific differences in the epidemiology, pathophysiology, and clinical presentation of AF and PVI are recognized. OBJECTIVE: We aimed at comparing the efficacy, safety, and procedural characteristics of CB and RF in women and men undergoing a first PVI procedure. METHODS: We searched for randomized controlled trials and prospective observational studies comparing CB and RF ablation with at least 1 year of follow-up. After merging individual patient data from 18 data sets, we investigated the sex-specific (procedure failure defined as recurrence of atrial arrhythmia, reablation, and reinitiation of antiarrhythmic medication), safety (periprocedural complications), and procedural characteristics of CB vs RF using Kaplan-Meier and multilevel models. RESULTS: From the 18 studies, 4840 men and 1979 women were analyzed. An analysis stratified by sex correcting for several covariates showed a better efficacy of CB in men (hazard ratio for recurrence 0.88; 95% confidence interval 0.78-0.98, P = .02) but not in women (hazard ratio 0.98; 95% confidence interval 0.83-1.16; P = .82). For women and men, the energy source had no influence on the occurrence of at least 1 complication. For both sexes, the procedure time was significantly shorter with CB (-22.5 minutes for women and -27.1 minutes for men). CONCLUSION: CB is associated with less long-term failures in men. A better understanding of AF-causal sex-specific mechanisms and refinements in CB technologies could lead to higher success rates in women.