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INTRODUCTION: Despite technical progress, ventricular tachycardia (VT) recurrence after unipolar ablation remains relatively high (12%-47%). Bipolar ablation has been proposed as an appealing solution that may overcome limitations associated with unipolar ablation settings. We designed an animal study to compare bipolar (BPA) vs sequential unipolar ablation (UPA) using contact force-sensing technology on both ablation catheters. METHODS: Twenty large white female pigs (6-months-old, 50-60 kg) underwent multiple RF ablations (30 W, 60 seconds, 30 mL/min irrigation) on the ventricular myocardium from the epicardial and endocardial sides. The hearts were fixed and scanned with high-resolution cardiac magnetic resonance imaging. Thermal lesions were located and characterized in volume, depth, width, and transmurality. RESULTS: Lesion volume was calculated as the sum of epicardial or endocardial conjoined/isolated lesions at one location. Linear dimensions (width and depth) were measured twice for each location, on the endocardial and epicardial side. We evaluated 35 lesions across the intraventricular septum (UPA, N = 17 vs BPA, N = 18). No difference in volume, linear dimensions or impedance drop was observed in this area between UPA and BPA. However, BPA required half RF time and showed an increased transmurality trend. We then analyzed 73 lesions from the endocardial side (UPA, N = 35 vs BPA, N = 38) and 50 from the epicardial side (UPA, N = 11 vs BPA N = 39) of the ventricular free walls. Lesion transmurality was markedly improved by BPA (P = .030, odds ratio, 23.73 [4.71,31.96]). Ventricular BPA lesions were significantly deeper on the epicardial side (P < .0001) and endocardial side (P = .015). CONCLUSION: Bipolar ablation is more likely to create transmural and epicardial lesions in the ventricle wall. Half the time is needed for the creation of comparably deep and large lesions.
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Cateteres Cardíacos , Ablação por Cateter/instrumentação , Ventrículos do Coração/cirurgia , Miocárdio/patologia , Transdutores de Pressão , Animais , Ablação por Cateter/efeitos adversos , Desenho de Equipamento , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Imageamento por Ressonância Magnética , Sus scrofaRESUMO
BACKGROUND: Choosing the appropriate animal model for development of novel technologies requires an understanding of anatomy and physiology of these different models. There are little data about the characteristics of different animal models for the study of technologies used for epicardial ablation. We aimed to compare the incidence of ventricular arrhythmias during epicardial radiofrequency ablation between swine and canine models using novel epicardial ablation catheters. METHODS: We conducted a retrospective study using data obtained from epicardial ablation experiments performed on swine (Sus Scrofa) and canine (Canis familiaris) models. We compared the incidence of ventricular arrhythmias during ablation between swine and canine using multivariate regression analysis. Six swine and six canine animals underwent successful epicardial radiofrequency ablation. A total of 103 ablation applications were recorded. RESULTS: Ventricular arrhythmias requiring cardioversion occurred in 13.11% of radiofrequency ablation applications in swine and 9.75% in canine (relative risk: 117.6%, 95% confidence interval [CI]: 83.97-164.69, animal-based odds ratio [OR]: .55, 95% CI: .23-61.33; P = .184). When adjusting for application position, duration of ablation and power, the odds of developing potentially lethal ventricular arrhythmia in swine increased significantly compared to canine (OR: 3.60, 95% CI: 1.35-9.55; P = .010). CONCLUSIONS: The swine myocardium is more susceptible to developing ventricular arrhythmias compared to canine model during epicardial ablation. This issue should be carefully considered in future studies.
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Ablação por Cateter/métodos , Modelos Animais de Doenças , Pericárdio/cirurgia , Taquicardia Ventricular/etiologia , Animais , Cães , Incidência , Estudos Retrospectivos , SuínosRESUMO
BACKGROUND: Patients with atrial fibrillation (AF) have an increased risk of diastolic dysfunction and heart failure. The purpose of this study was to identify independent predictors of early (ie, only exercise-induced) heart failure with preserved ejection fraction (HFpEF) and to describe the prevalence of early HFpEF among patients with paroxysmal AF. METHODS AND RESULTS: One hundred patients with paroxysmal AF and preserved left ventricular ejection fraction (LVEF) underwent catheterization for left atrial pressure (LAP) measurements at rest and at the peak of arm exercise (LAP-exe). Based on resting and exercise LAP values, the patients were divided into 3 groups. Sixty-one patients had no evidence of HFpEF (LAP at rest ≤15 mm Hg, LAP-exe <25 mm Hg). Twenty-five subjects had early HFpEF (LAP at rest ≤15 mm Hg, LAP-exe ≥25 mm Hg, prevalence 25%). Fourteen patients already had HFpEF at rest (LAP at rest >15 mm Hg). Multivariate exact logistic regression analysis identified age ≥58 years, LAP at rest ≥11 mm Hg, and peak systolic mitral annular velocity ≤9.3 cm/s to be independent predictors of early HFpEF. CONCLUSIONS: In patients with paroxysmal AF and preserved LVEF, there appears to be a clinically significant prevalence of early HFpEF.
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Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/epidemiologia , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/epidemiologia , Volume Sistólico/fisiologia , Idoso , Fibrilação Atrial/fisiopatologia , Estudos de Coortes , Diagnóstico Precoce , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Estudos ProspectivosRESUMO
AIMS: The objective of this study was to evaluate the mobility of the oesophagus and the stability of the three-dimensional (3D) model of the oesophagus using 3D rotational angiography (3DRA) of the left atrium (LA) and the oesophagus, fused with live fluoroscopy during catheter ablation for atrial fibrillation. METHODS AND RESULTS: From March 2015 to September 2015, 3DRA of the LA and the oesophagus was performed in 33 patients before catheter ablation for atrial fibrillation. Control contrast oesophagography was performed every 30 min. The positions of the oesophagograms and the 3D model of the LA and the oesophagus were repeatedly measured and compared with the spine. The average shift of the oesophagus ranged from 2.7 ± 2.2 to 5.0 ± 3.5 mm. The average real-time oesophageal shift ranged from 2.7 ± 2.2 to 3.8 ± 3.4 mm. No significant shift was detected until the 90th minute of the procedure. The average shift of the 3D model of the LA and the oesophagus ranged from 1.4 ± 1.8 to 3.3 ± 3.0 mm (right-left direction) and from 0.9 ± 1.2 to 2.2 ± 1.3 mm (craniocaudal direction). During the 2 h procedure, there were no significant shifts of the model. CONCLUSION: During catheter ablation for atrial fibrillation, there is no significant change in the position of the oesophagus until the 90th minute of the procedure and no significant shift in the 3D model of the LA and the oesophagus. The 3D model of the oesophagus reliably depicts the position of the oesophagus during the entire procedure.
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Angiografia/métodos , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Esôfago/diagnóstico por imagem , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Imageamento Tridimensional , Interpretação de Imagem Radiográfica Assistida por Computador , Radiografia Intervencionista/métodos , Cirurgia Assistida por Computador/métodos , Idoso , Pontos de Referência Anatômicos , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Feminino , Fluoroscopia , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Duração da Cirurgia , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Cirurgia Assistida por Computador/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Noninvasive diagnosis of exercise-induced elevation of left ventricular filling pressure is difficult and remains unsatisfactory. The aim of this study was to assess the accuracy of the ratio of early diastolic transmitral (E) to mitral annular (e') velocity and to determine new parameters or parameter combinations with the ability to predict exercise-induced left atrial pressure (LAP) elevation. METHODS AND RESULTS: Eighty patients with paroxysmal atrial fibrillation (AF) referred for catheter AF ablation underwent simultaneous exercise echocardiography and direct invasive LAP measurements, as well as a resting and postexercise biomarker analysis. Exercise E/e' ≥8.85 predicted exercise LAP ≥20 mm Hg with 61.5% sensitivity and 88.9% specificity (area under the curve [AUC], 0.76). Of all of the individual parameters tested, the best prediction was achieved with exercise E/s' (s'=peak systolic mitral annular velocity) ≥8.75 (sensitivity, 88.5%; specificity, 64.8%; positive predictive value, 54.8%; negative predictive value, 92.1%; AUC, 0.84). However, the combination of exercise E/A (A = late diastolic transmitral flow velocity) ≥1.22 + exercise E/e' ≥8.85 + exercise s'≤11.05 cm/s provided the most precise prediction of exercise LAP elevation (sensitivity, 84.6%; specificity, 79.6%; positive predictive value, 66.7%; negative predictive value, 91.5%; AUC, 0.90). CONCLUSIONS: Exercise E/e', when used as a sole parameter, was not sufficiently reliable to predict exercise-induced elevation of LAP. The application of a multivariate-adjusted combination of parameters appeared to be the preferable approach for the noninvasive prediction of exercise LAP elevation.
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Ecocardiografia/métodos , Exercício Físico/fisiologia , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Pressão Ventricular/fisiologia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Velocidade do Fluxo Sanguíneo , Diástole , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/fisiopatologia , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , SístoleRESUMO
(1) Background: Computer tomography (CT) is an imaging modality used in the pre-planning of radiofrequency catheter ablation (RFA) procedure in patients with cardiac arrhythmias. However, it is associated with a considerable ionizing radiation dose for patients. This study aims to develop and validate low-dose CT scanning protocols of the left atrium (LA) for RFA guidance. (2) Methods: 68 patients scheduled for RFA of atrial fibrillation were sequentially assigned to four groups of ECG-gated scanning protocols, based on the set tube current (TC): Group A (n = 20, TC = 33 mAs), Group B (n = 18, TC = 67 mAs), Group C (n = 10, TC = 135 mAs), and control Group D (n = 20, TC = 600 mAs). We used a 256-row multidetector CT with body weight-dependent tube voltage of 80 kVp (<70 kg), 100 kVp (70−90 kg), and 120 kVp (>90 kg). We evaluated scanning parameters including radiation dose, total scanning procedure time and signal-to-noise ratio (SNR). (3) Results: The average effective radiation dose (ED) was lower in Group A in comparison to Group B, C and D (0.83 (0.76−1.10), 1.55 (1.36−1.67), 2.91 (2.32−2.96) and 9.35 (8.00−10.04) mSv, p < 0.05). The total amount of contrast media was not significantly different between groups. The mean SNR was 6.5 (5.8−7.3), 7.1 (5.7−8.2), 10.8 (10.1−11.3), and 12.2 (9.9−15.7) for Group A, B, C and D, respectively. The comparisons of SNR in group A vs. B and C vs. D were without significant differences. (4) Conclusions: Optimized pre-ablation CT scanning protocols of the LA can reduce an average ED by 88.7%. Three dimensional (3D) models created with the lowest radiation protocol are useful for the integration of electro-anatomic-guided RFA procedures.
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AIMS: Three-dimensional rotational angiography (3DRA) of the left atrium (LA) and the esophagus is a simple and safe method for analyzing the relationship between the esophagus and the LA during catheter ablation of atrial fibrillation. The purpose of this study is to describe the location of the esophagus relative to the LA and mobility of the esophagus during ablation procedure. METHODS: From 3/2011 to 9/2015, 3DRA of the LA and esophagus was performed in 326 patients before catheter ablation of atrial fibrillation. 3DRAwas performed with visualization of the esophagus via peroral administration of a contrast agent. The positions of the esophagus were determined at the beginning of the procedure, for part of patients also at the end of procedure with contrast esophagography. RESULTS: The most frequent position is behind the center of the LA (91 pts., 31.9%) The least frequent position is behind the right pulmonary veins (27 pts., 9.4%). The average shift of the esophagus position was 3.36±2.15mm, 3.59±2.37mm and 3.67±3.23mm for superior, middle and inferior segment resp. CONCLUSIONS: The position of the esophagus to the LA is highly variable. The most common position of the esophagus relative to the LA is behind the middle and left part of the posterior wall of the LA. The least frequently observed position is behind the right pulmonary veins. No significant position change of esophagus motion from before to after the ablation procedure in the majority (≥95%) of the patients was observed.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Angiografia por Tomografia Computadorizada/métodos , Esôfago/diagnóstico por imagem , Fluoroscopia/métodos , Imageamento Tridimensional/métodos , Cirurgia Assistida por Computador/métodos , Fibrilação Atrial/diagnóstico , Feminino , Átrios do Coração/diagnóstico por imagem , Sistema de Condução Cardíaco/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
PURPOSE: To demonstrate the feasibility of directional percutaneous epicardial ablation using a partially insulated catheter. METHODS: Partially insulated catheter prototypes were tested in 12 (6 canine, 6 porcine) animal studies in two centers. Prototypes had interspersed windows to enable visualization of epicardial structures with ultrasound. Epicardial unipolar ablation and ablation between two electrodes was performed according to protocol (5-60 W power, 0-60 mls/min irrigation, 78 s mean duration). RESULTS: Of 96 epicardial ablation attempts, unipolar ablation was delivered in 53.1%. Electrogram evidence of ablation, when analyzable, occurred in 75 of 79 (94.9%) therapies. Paired pre/post-ablation pacing threshold (N = 74) showed significant increase in pacing threshold post-ablation (0.9 to 2.6 mA, P < .0001). Arrhythmias occurred in 18 (18.8%) therapies (11 ventricular fibrillation, 7 ventricular tachycardia), mainly in pigs (72.2%). Coronary artery visualization was variably successful. No phrenic nerve injury was noted during or after ablation. Furthermore, there were minimal pericardial changes with ablation. CONCLUSIONS: Epicardial ablation using a partially insulated catheter to confer epicardial directionality and protect the phrenic nerve seems feasible. Iterations with ultrasound windows may enable real-time epicardial surface visualization thus identifying coronary arteries at ablation sites. Further improvements, however, are necessary.
Assuntos
Ablação por Cateter/instrumentação , Desenho de Equipamento , Complicações Intraoperatórias/prevenção & controle , Nervo Frênico/lesões , Taquicardia Ventricular/cirurgia , Animais , Área Sob a Curva , Cateteres Cardíacos , Ablação por Cateter/métodos , Modelos Animais de Doenças , Cães , Estudos de Viabilidade , Feminino , Distribuição Aleatória , Sensibilidade e Especificidade , Suínos , Taquicardia Ventricular/diagnóstico por imagemRESUMO
INTRODUCTION: Epicardial defibrillation systems currently require surgical access. We aimed to develop a percutaneous defibrillation system with partially-insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extra-cardiac stimulation. METHODS: We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath. This included a partially-insulated defibrillation coil and a defibrillation mesh with a urethane balloon acting as an insulator to the face of the mesh not in contact with the epicardium. The average energy associated with a chance of successful defibrillation 75% of the time (ED75) was calculated for each experiment. RESULTS: Of 16 animal experiments, 3 pig experiments had malfunctioning mesh prototypes such that results were unreliable; these were excluded. Therefore, 13 animal experiments were analyzed - 6 canines (29.8±4.0kg); 7 pigs (41.1±4.4kg). The overall ED75 was 12.8±6.7J (10.9±9.1J for canines; 14.4±3.9J in pigs [P=0.37]). The lowest ED75 obtained in canines was 2.5J while in pigs it was 9.5J. The lowest energy resulting in successful defibrillation was 2J in canines and 5J in pigs. There was no evidence of coronary vessel injury or trauma to extra-pericardial structures. CONCLUSION: Percutaneous, epicardial defibrillation using a partially insulated coil is feasible and appears to be associated with low defibrillation thresholds. Focusing insulation may limit extra-cardiac stimulation and potentially lower energy requirements for efficient defibrillation.
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Desfibriladores , Animais , Cães , Cardioversão Elétrica/instrumentação , Cardioversão Elétrica/métodos , Feminino , Masculino , Pericárdio , SuínosRESUMO
PURPOSE: Computed tomography (CT) and 3D rotational angiography (3DRA) of the left atrium (LA) are used to evaluate the esophagus prior to radiofrequency ablation for atrial fibrillation. The aim of this study was to compare preprocedural and periprocedural views of the esophagus and the left atrium. METHODS: From September 2011 to August 2012, 3DRA and CT of the LA were performed on 56 patients before they underwent catheter ablation of atrial fibrillation. The 3DRA was performed periprocedurally, and the CT was performed an average of 20 days prior to the procedure. 3D models of the LA and the esophagus were then segmented on the EP Navigator V 3.1 workstation. Five positions of the esophagus, A-E, in order from left to right, were evaluated. RESULTS: The most common position of the esophagus was behind the left part of the LA (CT, position B (n = 26)) and behind the central part of the LA (3DRA, position C (n = 21)). The maximum shift of the esophagus was three positions, and the average shift was 0.857 ± 0.766 of a position. There was a shift of one position in 44.6 % of the patients, two positions in 17.9 %, and three positions in 1.8 %. A statistically significant difference was found between the positions of the esophagus when the 3DRA and CT evaluations were compared. CONCLUSIONS: The most common position of the esophagus was behind the middle and left part of the LA. The outpatient views of the esophagus obtained before ablation did not reflect the position of the esophagus at the beginning of the procedure.
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Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Ablação por Cateter , Esôfago/diagnóstico por imagem , Imageamento Tridimensional , Cirurgia Assistida por Computador , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Esôfago/cirurgia , Feminino , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Cuidados Pós-Operatórios , Cuidados Pré-Operatórios , Reprodutibilidade dos Testes , Estudos Retrospectivos , Rotação , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
A new method in creating 3D models of the left atrium (LA) and esophagus before catheter ablation of atrial arrhythmias is 3D rotational angiography (3DRA) of the LA. The purpose of this retrospective study was to test various acquisition protocols of the 3DRA and attempt to define the parameters influencing the success of the protocols. From August 2010 to November 2014, 3DRA of the LA using the Philips Allura FD 10 X-ray system was performed in 547 consecutive patients using right atrial and left atrial protocols. Visualization of the esophagus was performed after oral administration of a contrast agent. Patients were monitored for success (creation of a useful 3D models) and evaluated for a number of parameters affecting the success of 3DRA. The success of the RA protocol was 88.89 % with and 91.91 % without esophagus imaging. The success of the LA protocol was 97.42 % with and 94.54 % without esophagus imaging. The only factor reducing the success of the RA protocol was BMI; the LA protocol was not influenced by any factor. Ventricular fibrillation induced in two patients was successfully treated with defibrillation. 3DRA of the LA is a reliable method that supports catheter ablation of complex atrial arrhythmias. The LA protocol with esophagus imaging was significantly more reliable than the RA protocol; the other protocols were comparable. The RA protocol may be negatively affected by high BMI. Simultaneous imaging of the esophagus is safe and feasible, and the LA protocol can be recommended.
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Angiografia/métodos , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Ablação por Cateter , Esôfago/diagnóstico por imagem , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Imageamento Tridimensional , Interpretação de Imagem Radiográfica Assistida por Computador , Idoso , Fibrilação Atrial/fisiopatologia , Índice de Massa Corporal , Simulação por Computador , Meios de Contraste/administração & dosagem , Feminino , Átrios do Coração/fisiopatologia , Humanos , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
Atrial fibrillation is the most common sustained arrhythmia. Because of the sub-optimal outcomes and associated risks of medical therapy as well as the recent advances in non-pharmacologic strategies, a multitude of combined (hybrid) algorithms have been introduced that improve efficacy of standalone therapies while maintaining a high safety profile. Antiarrhythmic administration enhances success rate of electrical cardioversion. Catheter ablation of antiarrhythmic drug-induced typical atrial flutter may prevent recurrent atrial fibrillation. Through simple ablation in the right atrium, suppression of atrial fibrillation may be achieved in patients with previously ineffective antiarrhythmic therapy. Efficacy of complex catheter ablation in the left atrium is improved with antiarrhythmic drugs. Catheter ablation followed by permanent pacemaker implantation is an effective and safe treatment option for selected patients. Additional strategies include pacing therapies such as atrial pacing with permanent pacemakers, preventive pacing algorithms, and/or implantable dual-chamber defibrillators are available. Modern hybrid strategies combining both epicardial and endocardial approaches in order to create a complex set of radiofrequency lesions in the left atrium have demonstrated a high rate of success and warrant further research. Hybrid therapy for atrial fibrillation reviews history of development of non-pharmacological treatment strategies and outlines avenues of ongoing research in this field.
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Fibrilação Atrial/terapia , Animais , Antiarrítmicos/uso terapêutico , Flutter Atrial/tratamento farmacológico , Estimulação Cardíaca Artificial , Ablação por Cateter , Terapia Combinada , HumanosRESUMO
Three-dimensional rotational angiography (3 DRA) is a novel imaging method introduced to guide complex catheter ablations of the left atrium. Our aim was to investigate the feasibility of the method in visualization of left ventricular anatomy and to develop a corresponding protocol for guidance of ventricular tachycardia ablation. We performed 3D rotational angiography in 13 patients using a direct left atrial protocol for data acquisition and the 3D reconstruction of the left ventricle was achieved in all patients. Clinical data comparison has proved lower use of radiation and contrast medium during 3 DRA-guided ablations as compared to CT-guided procedures.
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Ablação por Cateter , Angiografia Coronária/métodos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/cirurgia , Radiografia Intervencionista/métodos , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/cirurgia , Idoso , Meios de Contraste , Estudos de Viabilidade , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Resultado do TratamentoRESUMO
BACKGROUND: Catheter ablation in the left atrium has become a common therapeutic strategy in the management of atrial fibrillation (AF). The high degree of success and safety profile of this procedure is dependent on precise knowledge of the true anatomy in the chamber. This information is imported mostly from cardiac computed tomography. A novel method for imaging the left atrial anatomy is three-dimensional rotational angiography (3DRA). METHODS: The aim of our study was to the compare clinical outcome and safety of catheter ablation for atrial fibrillation guided by 3DRA vs. conventional CT scan. One hundred and twenty-five patients referred for AF catheter ablation at St. Anne's University Hospital Brno were included in the retrospective analysis of clinical outcome within the first year after the procedure. RESULTS: There was a close correlation in overall procedural parameters between the groups. The frequency of recurrent episodes of AF (24% in CT-guided group vs. 27% in 3DRA-guided group, P=0.721) as well as the onset of atypical atrial flutter after the procedure (10% vs. 8%, respectively, P=0.731) were similar in both groups. No difference in the number of patients necessitating repeat ablation (5% vs. 5%, P=0.984) was found. Procedural complications of ablations guided by 3DRA were comparable with those guided by CT (2% vs. 3%, respectively, P=0.568). CONCLUSION: 3DRA has proven to be a safe and simple method for imaging the left atrium and guiding catheter ablation for AF. This approach is anticipated to become a new standard in 3D reconstruction of the left atrium.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Angiografia/métodos , Fibrilação Atrial/diagnóstico por imagem , Ablação por Cateter/efeitos adversos , Feminino , Átrios do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Veias Pulmonares/diagnóstico por imagem , Radiografia Intervencionista/métodos , Recidiva , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
INTRODUCTION: Epicardial cardiac resynchronization therapy (CRT) permits unrestricted electrode positioning. However, this requires surgical placement of device leads and the risk of unwanted phrenic nerve stimulation. We hypothesized that shielded electrodes can capture myocardium without extracardiac stimulation. METHODS: In 6 dog and 5 swine experiments, we used a percutaneous approach to access the epicardial surface of the heart, and deploy novel leads housing multiple electrodes with selective insulation. Bipolar pacing thresholds at prespecified sites were tested compare electrode threshold data both facing towards and away from the epicardial surface. RESULTS: In 151 paired electrode recordings (70 in 6 dogs; 81 in 5 swine), thresholds facing myocardium were lower than facing away (median [IQR] mA: dogs 0.9 [0.4-1.6] vs 4.6 [2.1 to >10], p<0.0001; swine 0.5 [0.2-1] vs 2.5 [0.5-6.8], p<0.0001). Myocardial capture was feasible without extracardiac stimulation at all tested sites, with mean ± SE threshold margin 3.6±0.7 mA at sites of high output extracardiac stimulation (p=0.004). CONCLUSION: Selective electrode insulation confers directional pacing to a multielectrode epicardial pacing lead. This device has the potential for a novel percutaneous epicardial resynchronization therapy that permits placement at an optimal pacing site, irrespective of the anatomy of the coronary veins or phrenic nerves.
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Cardiac arrhythmias are a very frequent illness. Pharmacotherapy is not very effective in persistent arrhythmias and brings along a number of risks. Catheter ablation has became an effective and curative treatment method over the past 20 years. To support complex arrhythmia ablations, the 3D X-ray cardiac cavities imaging is used, most frequently the 3D reconstruction of CT images. The 3D cardiac rotational angiography (3DRA) represents a modern method enabling to create CT like 3D images on a standard X-ray machine equipped with special software. Its advantage lies in the possibility to obtain images during the procedure, decreased radiation dose and reduction of amount of the contrast agent. The left atrium model is the one most frequently used for complex atrial arrhythmia ablations, particularly for atrial fibrillation. CT data allow for creation and segmentation of 3D models of all cardiac cavities. Recently, a research has been made proving the use of 3DRA to create 3D models of other cardiac (right ventricle, left ventricle, aorta) and non-cardiac structures (oesophagus). They can be used during catheter ablation of complex arrhythmias to improve orientation during the construction of 3D electroanatomic maps, directly fused with 3D electroanatomic systems and/or fused with fluoroscopy. An intensive development in the 3D model creation and use has taken place over the past years and they became routinely used during catheter ablations of arrhythmias, mainly atrial fibrillation ablation procedures. Further development may be anticipated in the future in both the creation and use of these models.