RESUMO
BACKGROUND: The tissue selectivity of pulsed field ablation (PFA) provides safety advantages over radiofrequency ablation in treating atrial fibrillation. One-shot PFA catheters have been shown capable of performing pulmonary vein isolation, but not flexible lesion sets such as linear lesions. A novel lattice-tip ablation catheter with a compressible 9-mm nitinol tip is able to deliver either focal radiofrequency ablation or PFA lesions, each in 2 to 5 s. METHODS: In a 3-center, single-arm, first-in-human trial, the 7.5F lattice catheter was used with a custom mapping system to treat paroxysmal or persistent atrial fibrillation. Toggling between energy sources, point-by-point pulmonary vein encirclement was performed using biphasic PFA posteriorly and either temperature-controlled irrigated radiofrequency ablation or PFA anteriorly (RF/PF or PF/PF, respectively). Linear lesions were created using either PFA or radiofrequency ablation. RESULTS: The 76-patient cohort included 55 paroxysmal and 21 persistent atrial fibrillation patients undergoing either RF/PF (40 patients) or PF/PF (36 patients) ablation. The pulmonary vein isolation therapy duration time (transpiring from first to last lesion) was 22.6±8.3 min/patient, with a mean of 50.1 RF/PF lesions/patient. Linear lesions included 14 mitral (4 RF/2 RF+PF/8 PF), 34 left atrium roof (12 RF/22 PF), and 44 cavotricuspid isthmus (36 RF/8 PF) lines, with therapy duration times of 5.1±3.5, 1.8±2.3, and 2.4±2.1 min/patient, respectively. All lesion sets were acutely successful, using 4.7±3.5 minutes of fluoroscopy. There were no device-related complications, including no strokes. Postprocedure esophagogastroduodenoscopy revealed minor mucosal thermal injury in 2 of 36 RF/PF and 0 of 24 PF/PF patients. Postprocedure brain magnetic resonance imaging revealed diffusion-weighted imaging+/fluid-attenuated inversion recovery- and diffusion-weighted imaging+/fluid-attenuated inversion recovery+ asymptomatic lesions in 5 and 3 of 51 patients, respectively. CONCLUSIONS: A novel lattice-tip catheter could safely and rapidly ablate atrial fibrillation using either a combined RF/PF approach (capitalizing on the safety of PFA and the years of experience with radiofrequency energy) or an entirely PF approach. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT04141007 and NCT04194307.
Assuntos
Fibrilação Atrial/cirurgia , Cateterismo Cardíaco/instrumentação , Cateteres Cardíacos , Ablação por Cateter/instrumentação , Veias Pulmonares/cirurgia , Irrigação Terapêutica/instrumentação , Potenciais de Ação , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Cateterismo Cardíaco/efeitos adversos , Ablação por Cateter/efeitos adversos , República Tcheca , Técnicas Eletrofisiológicas Cardíacas , Desenho de Equipamento , Feminino , Frequência Cardíaca , Humanos , Lituânia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Veias Pulmonares/fisiopatologia , Irrigação Terapêutica/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
In stable ventricular tachycardia (VT), activation mapping and entrainment mapping are the most important strategies to describe the reentrant circuit and its critical components. In many patients, however, VT is noninducible or hemodynamically unstable and unmappable. Several technological advances have broadened ablation options in unmappable VTs. Preprocedural imaging and intraprocedural imaging play an important role in location and extent of the substrate. Electroanatomic mapping with several technological improvements allows more precise electrical assessment of the substrate. A combination of imaging and electroanatomic mapping allows substantial modification of arrhythmogenic substrate in sinus rhythm or during device pacing without hemodynamic compromise.
Assuntos
Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Infarto do Miocárdio , Taquicardia Ventricular , Algoritmos , Técnicas de Imagem Cardíaca , Eletrocardiografia , Humanos , Imageamento por Ressonância Magnética , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/cirurgia , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgiaRESUMO
AIMS: Stereotactic body radiotherapy (SBRT) for ventricular tachycardias (VTs) could be an option after failed catheter ablation. In this study, we analysed the long-term efficacy and toxicity of SBRT applied as a bail-out procedure. METHODS AND RESULTS: Patients with structural heart disease and unsuccessful catheter ablations for VTs underwent SBRT. The planning target volume (PTV) was accurately delineated using exported 3D electroanatomical maps with the delineated critical part of re-entry circuits. This was defined by detailed electroanatomic mapping and by pacing manoeuvres during the procedure. Using the implantable cardioverter-defibrillator lead as a surrogate contrast marker for respiratory movement compensation, 25 Gy was delivered to the PTV using CyberKnife. We evaluated occurrences of sustained VT, electrical storm, antitachycardia pacing, and shock; time to death; and radiation-induced events. From 2014 until March 2017, 10 patients underwent radiosurgical ablation (mean PTV, 22.15 mL; treatment duration, 68 min). After radiosurgery, four patients experienced nausea and one patient presented gradual progression of mitral regurgitation. During the follow-up (median 28 months), VT burden was reduced by 87.5% compared with baseline (P = 0.012) and three patients suffered non-arrhythmic deaths. After the blanking period, VT recurred in eight of 10 patients. The mean time to first antitachycardia pacing and shock were 6.5 and 21 months, respectively. CONCLUSION: Stereotactic body radiotherapy appears to show long-term safety and effectiveness for VT ablation in structural heart disease inaccessible to catheter ablation. We report one possible radiation-related toxicity and promising overall survival, warranting evaluation in a prospective multicentre clinical trial.
Assuntos
Radiocirurgia/métodos , Taquicardia Ventricular/radioterapia , Idoso , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.
Assuntos
Eletrofisiologia Cardíaca , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas/métodos , Taquicardia Ventricular , Complexos Ventriculares Prematuros , Eletrofisiologia Cardíaca/organização & administração , Eletrofisiologia Cardíaca/normas , Eletrofisiologia Cardíaca/tendências , Ablação por Cateter/instrumentação , Ablação por Cateter/métodos , Ablação por Cateter/normas , Consenso , Sistema de Condução Cardíaco/patologia , Sistema de Condução Cardíaco/fisiopatologia , Sistema de Condução Cardíaco/cirurgia , Cardiopatias/classificação , Cardiopatias/complicações , Humanos , Cooperação Internacional , Melhoria de Qualidade/organização & administração , Sociedades Médicas , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgia , Resultado do Tratamento , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/etiologia , Complexos Ventriculares Prematuros/fisiopatologia , Complexos Ventriculares Prematuros/cirurgiaAssuntos
Flutter Atrial/diagnóstico , Cateterismo Cardíaco/instrumentação , Cateteres Cardíacos , Ablação por Cateter/instrumentação , Remoção de Dispositivo/instrumentação , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Falha de Equipamento , Idoso , Flutter Atrial/fisiopatologia , Cateterismo Cardíaco/efeitos adversos , Remoção de Dispositivo/métodos , Técnicas Eletrofisiológicas Cardíacas/efeitos adversos , Humanos , MasculinoRESUMO
INTRODUCTION: Frequent ventricular premature complexes (VPCs) may cause symptoms and/or lead to deterioration of LV systolic function. Although frequent VPCs may be abolished by catheter ablation, it may be challenging in case of their origin from the LV papillary muscles (PMs). Our collaborative study aimed to analyze in detail the site of origin and the outcome of ablation. METHODS: Consecutive 34 patients (males: 68%; aged 62 ± 12 years; LV ejection fraction: 50 ± 9%) undergoing catheter ablation of VPCs originating from PMs were included. All procedures were guided by intracardiac echocardiography. RESULTS: The size and shape of PMs were highly variable. The length of anterolateral and posteromedial PM was 23 ± 4 mm and 28 ± 7 mm, respectively. In about one-third of patients, the PM was formed by two distinctly separate heads. The ectopic foci were located on anterolateral, posteromedial or both PM in 35%, 56% and 9% of cases, respectively. Their location was found within the distal, mid, or proximal (basal) third of PM in the 67%, 19%, and 14%, respectively. A total of 86% of PM foci were acutely abolished and long-term success was achieved in 65% of patients. Absence of VPCs of other morphologies and a high burden of ectopic activity before ablation were associated with favorable clinical outcome. CONCLUSION: VPCs originate predominantly from the distal portion of the PM. This knowledge may facilitate the mapping in patients with infrequent ectopic beats. Intracardiac echocardiography is of crucial importance for navigation of the ablation catheter and for assessment of its stability at PM target sites.
Assuntos
Frequência Cardíaca , Ventrículos do Coração/fisiopatologia , Músculos Papilares/fisiopatologia , Função Ventricular Esquerda , Complexos Ventriculares Prematuros/fisiopatologia , Potenciais de Ação , Idoso , Ablação por Cateter , Ecocardiografia , Técnicas Eletrofisiológicas Cardíacas , Europa (Continente) , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Papilares/diagnóstico por imagem , Músculos Papilares/cirurgia , Fatores de Tempo , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/cirurgiaAssuntos
Ablação por Cateter , Implante de Prótese de Valva Cardíaca/efeitos adversos , Valva Pulmonar/transplante , Complexos Ventriculares Prematuros/cirurgia , Potenciais de Ação , Adolescente , Ecocardiografia , Técnicas Eletrofisiológicas Cardíacas , Frequência Cardíaca , Humanos , Masculino , Resultado do Tratamento , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/etiologia , Complexos Ventriculares Prematuros/fisiopatologiaRESUMO
AIMS: In patients with severe neurally mediated syncope (NMS), radiofrequency catheter ablation (RFA) of ganglionic plexi (GP) has been proposed as a new therapeutic approach. Cardio-inhibitory response during NMS is usually related to the sinoatrial (SA) and less frequently to atrioventricular (AV) node. Differential effect of GP ablation on SA and AV node is poorly understood. METHODS AND RESULTS: We report a case of a 35-year-old female with frequent symptomatic episodes of advanced AV block treated by anatomically guided RFA at empirical sites of GPs. After RFA at the septal portion of the right atrium-superior vena cava junction, heart rate accelerated from 62 to 91 beats/min and PR interval prolonged from 213 to 344 ms. Sustained first-degree AV block allowed to observe directly the effects of subsequent RFA on the AV nodal properties. Subsequent RFA at right- and left-sided aspects of the inter-atrial septum had no further effect on heart rate and PR interval. Ablation at the inferior left GP was critical for restoration of normal AV conduction (final PR interval of 187 ms). No bradycardia episodes were observed by implantable loop recorder during the follow-up of 10 months and the patient was symptomatically improved. CONCLUSION: This is the first clinical case showing the differential effect of GP ablation on SA and AV nodal function, and critical importance of targeting the GP at the postero-inferior left atrium. The successful procedure corroborates clinical utility of ablation treatment instead of pacemaker implantation in selected patients with cardio-inhibitory NMS.
Assuntos
Bloqueio Atrioventricular/cirurgia , Nó Atrioventricular/fisiopatologia , Denervação Autônoma/métodos , Ablação por Cateter , Gânglios Autônomos/cirurgia , Nó Sinoatrial/fisiopatologia , Síncope Vasovagal/cirurgia , Potenciais de Ação , Adulto , Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/fisiopatologia , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Gânglios Autônomos/fisiopatologia , Frequência Cardíaca , Humanos , Recidiva , Índice de Gravidade de Doença , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVES: This study sought to evaluate an investigational catheter that incorporates 3 microelectrodes embedded along the circumference of a standard 3.5-mm open-irrigated catheter. BACKGROUND: Mapping resolution is influenced by both electrode size and interelectrode spacing. Multielectrode mapping catheters enhance mapping resolution within scar compared with standard ablation catheters; however, this requires the use of 2 separate catheters for mapping and ablation. METHODS: Six swine with healed infarction and 2 healthy controls underwent mapping of the left ventricle using a THERMOCOOL SMARTTOUCH SF catheter with 3 additional microelectrodes (0.167 mm2) along its circumference (Qdot, Biosense Webster, Diamond Bar, California). Mapping resolution in healthy and scarred tissue was compared between the standard electrodes and microelectrodes using electrogram characteristics, cardiac magnetic resonance, and histology. RESULTS: In healthy myocardium, bipolar voltage amplitude was similar between the standard electrodes and microelectrodes, with a fifth percentile of 1.19 and 1.30 mV, respectively. In healed infarction, the area of low bipolar voltage (defined as <1.5 mV) was smaller with microelectrodes (16.8 cm2 vs. 25.3 cm2; p = 0.033). Specifically, the microelectrodes detected zones of increased bipolar voltage amplitude, with normal electrogram characteristics occurring at the end of or after the QRS, consistent with channels of preserved subendocardium. Identification of surviving subendocardium by the microelectrodes was consistent with cardiac magnetic resonance and histology. The microelectrodes also improved distinction between near-field and far-field electrograms, with more precise identification of scar border zones. CONCLUSIONS: This novel catheter combines high-resolution mapping and radiofrequency ablation with an open-irrigated, tissue contact-sensing technology. It improves scar mapping resolution while limiting the need for and cost associated with the use of a separate mapping catheter.
Assuntos
Mapeamento Potencial de Superfície Corporal/instrumentação , Ablação por Cateter/instrumentação , Cicatriz/fisiopatologia , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Ventrículos do Coração/fisiopatologia , Microeletrodos/efeitos adversos , Animais , Cicatriz/patologia , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas/métodos , Endocárdio/patologia , Endocárdio/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Espectroscopia de Ressonância Magnética/métodos , Masculino , Microeletrodos/normas , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Estudos Prospectivos , Suínos , Taquicardia Ventricular/fisiopatologiaRESUMO
BACKGROUND: Left ventricular assist devices (LVADs) are increasingly used as a bridge to cardiac transplantation or as destination therapy. Patients with LVADs are at high risk for ventricular arrhythmias. This study describes ventricular arrhythmia characteristics and ablation in patients implanted with a Heart Mate II device. METHODS AND RESULTS: All patients with a Heart Mate II device who underwent ventricular arrhythmia catheter ablation at 9 tertiary centers were included. Thirty-four patients (30 male, age 58±10 years) underwent 39 ablation procedures. The underlying cardiomyopathy pathogenesis was ischemic in 21 and nonischemic in 13 patients with a mean left ventricular ejection fraction of 17%±5% before LVAD implantation. One hundred and ten ventricular tachycardias (VTs; cycle lengths, 230-740 ms, arrhythmic storm n=28) and 2 ventricular fibrillation triggers were targeted (25 transseptal, 14 retrograde aortic approaches). Nine patients required VT ablation <1 month after LVAD implantation because of intractable VT. Only 10/110 (9%) of the targeted VTs were related to the Heart Mate II cannula. During follow-up, 7 patients were transplanted and 10 died. Of the remaining 17 patients, 13 were arrhythmia-free at 25±15 months. In 1 patient with VT recurrence, change of turbine speed from 9400 to 9000 rpm extinguished VT. CONCLUSIONS: Catheter ablation of VT among LVAD recipients is feasible and reasonably safe even soon after LVAD implantation. Intrinsic myocardial scar, rather than the apical cannula, seems to be the dominant substrate.
Assuntos
Ablação por Cateter , Insuficiência Cardíaca/terapia , Coração Auxiliar , Taquicardia Ventricular/cirurgia , Função Ventricular Esquerda , Potenciais de Ação , Idoso , Técnicas Eletrofisiológicas Cardíacas , Europa (Continente) , Estudos de Viabilidade , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Coração Auxiliar/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de Risco , Volume Sistólico , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/mortalidade , Taquicardia Ventricular/fisiopatologia , Centros de Atenção Terciária , Fatores de Tempo , Resultado do Tratamento , Estados UnidosRESUMO
BACKGROUND: Idiopathic ventricular tachycardia (VT) and/or premature ventricular contractions (PVCs) arise most commonly from the right ventricular outflow tract and less frequently from the left ventricular outflow tract (LVOT), either below or above the semilunar valves. CASE PRESENTATION: We report a case of 24-year-old man with idiopathic ventricular tachycardia from a single focus in the supravalvular left ventricular outflow tract with two extremely divergent breakouts observed during the ablation procedure. CONCLUSION: Focal sources of ventricular arrhythmia in the aortic root may have different preferential exits and meticulous activation sequence mapping is the preferable strategy to delineate the site of origin.
Assuntos
Sistema de Condução Cardíaco/fisiopatologia , Ventrículos do Coração/fisiopatologia , Taquicardia Ventricular/fisiopatologia , Complexos Ventriculares Prematuros/fisiopatologia , Potenciais de Ação , Ablação por Cateter , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/cirurgia , Ventrículos do Coração/cirurgia , Humanos , Masculino , Valor Preditivo dos Testes , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/cirurgia , Resultado do Tratamento , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/cirurgia , Adulto JovemRESUMO
BACKGROUND: During radiofrequency ablation, high electrode-tissue contact force (CF) is associated with increased risk of steam pop and perforation. The purpose of this study, in patients undergoing ablation of paroxysmal atrial fibrillation, was to: (1) identify factors producing high CF during left atrial (LA) and pulmonary vein mapping; (2) determine the ability of atrial potential amplitude and impedance to predict CF; and (3) explore the feasibility of controlling radiofrequency power based on CF. METHODS AND RESULTS: A high-density map of LA/pulmonary veins (median 328 sites) was obtained in 18 patients undergoing atrial fibrillation ablation using a 7.5-Fr irrigated mapping/ablation catheter to measure CF. Average CF was displayed on the 3D map. For 5682 mapped sites, CF ranged 1-144 g (median 8.2 g). High CF (≥35 g) was observed at only 118/5682 (2%) sites, clustering in 6 LA regions. The most common high CF site (48/113 sites in 17/18 patients) was located at the anterior/rightward LA roof, directly beneath the ascending aorta (confirmed by merging the CT image and map). Poor relationship between CF and either unipolar amplitude, bipolar amplitude, or impedance was observed. During ablation, radiofrequency power was modulated based on CF. All pulmonary veins were isolated without steam pop, impedance rise, or pericardial effusion. CONCLUSIONS: High CF often occurs at anterior/rightward roof, where the ascending aorta provides resistance to the LA. Atrial potential amplitude and impedance are poor predictors of CF. Controlling radiofrequency power based on CF seems to prevent steam pop and impedance rise without loss of lesion effectiveness.
Assuntos
Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas , Potenciais de Ação , Adulto , Idoso , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/instrumentação , Impedância Elétrica , Eletrodos , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Átrios do Coração/fisiopatologia , Átrios do Coração/cirurgia , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/etiologia , Derrame Pericárdico/prevenção & controle , Valor Preditivo dos Testes , Veias Pulmonares/fisiopatologia , Veias Pulmonares/cirurgia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
BACKGROUND: The visually guided laser ablation (VGLA) catheter is a compliant, variable-diameter balloon that delivers laser energy around the pulmonary vein (PV) ostium under real-time endoscopic visualization. While acute PV isolation has been shown to be feasible, limited data exist regarding the durability of isolation. OBJECTIVE: We sought to determine the durability of PV isolation following ablation using the balloon-based VGLA catheter. METHODS: The VGLA catheter was evaluated in patients with paroxysmal atrial fibrillation (3 sites, 10 operators). Following transseptal puncture, the VGLA catheter was advanced through a 12-F deflectable sheath and inflated at the target PV ostium. Under endoscopic guidance, the 30° aiming arc was maneuvered around the PV and laser energy was delivered to ablate tissue in a contiguous/overlapping manner. At â¼3 months, all patients returned for a PV remapping procedure. RESULTS: In 56 patients, 202 of 206 PVs (98%) were acutely isolated. At 105 ± 44 (mean ± SD) days, 52 patients returned for PV remapping at which time 162 of 189 PVs (86%) remained isolated and 32 of 52 patients (62%) had all PVs still isolated. On comparing the operators performing <10 vs ≥ 10 procedures, the durable PV isolation rate and the percentage of patients with all PVs isolated were found to be 73% vs 89% (P = .011) and 57% vs 66% (P = .746), respectively. After 2 procedures and 12.0 ± 1.9 months of follow-up, the drug-free rate of freedom from atrial fibrillation was 71.2%. CONCLUSIONS: In this multicenter, multioperator experience, VGLA resulted in a very high rate of durable PV isolation with a clinical efficacy similar to that of radiofrequency ablation.
Assuntos
Angioscopia/métodos , Fibrilação Atrial/cirurgia , Ablação por Cateter/instrumentação , Cateterismo/instrumentação , Sistema de Condução Cardíaco/cirurgia , Terapia a Laser/instrumentação , Veias Pulmonares/cirurgia , Adolescente , Adulto , Idoso , Angiografia , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/fisiopatologia , Técnicas Eletrofisiológicas Cardíacas , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Seguimentos , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
We present a 34-year-old woman with idiopathic ventricular tachycardia that resisted 2 previous attempts for catheter ablation and was successfully ablated in the myocardial extension within the noncoronary aortic cusp.
Assuntos
Valva Aórtica/cirurgia , Ablação por Cateter , Ventrículos do Coração/cirurgia , Taquicardia Ventricular/cirurgia , Potenciais de Ação , Adulto , Valva Aórtica/fisiopatologia , Estimulação Cardíaca Artificial , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Miocárdio , Reoperação , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Imagens com Corantes Sensíveis à VoltagemRESUMO
INTRODUCTION: 3D echocardiography allows imaging and analysis of cardiovascular structures as they move in time and space, thus creating possibility for creation of 4D datasets (3D + time). Intracardiac echocardiography (ICE) further broadens the spectrum of echocardiographic techniques by allowing detailed imaging of intracardiac anatomy with 3D reconstructions. The paper reviews the current status of development of 3D and 4D echocardiography in electrophysiology. In ablation area, 3D echocardiography can enhance the performance of catheter ablation for complex arrhythmias such as atrial fibrillation. Currently, several strategies to obtain 3D reconstructions from ICE are available. One involves combination with electroanatomical mapping system; others create reconstruction from standard phased-array or single-element ICE catheter using special rotational or pull-back devices. Secondly, 3D echocardiography may be used for precise assessment of cardiac dyssynchrony before cardiac resynchronization therapy. Its reliable detection is expected to minimize number of non-responders to this treatment and optimize left ventricular lead positioning to get maximum hemodynamic benefit. CONCLUSION: The main potential benefit of 3D and 4D echocardiography in electrophysiology lie in real-time guidance of complex ablation procedures and precise assessment of cardiac dyssynchrony.
Assuntos
Arritmias Cardíacas/diagnóstico por imagem , Ecocardiografia Quadridimensional/métodos , Ecocardiografia Tridimensional/métodos , Arritmias Cardíacas/terapia , Cateterismo Cardíaco , Ablação por Cateter , Cardioversão Elétrica/métodos , Técnicas Eletrofisiológicas Cardíacas , HumanosRESUMO
The prognosis for patients with idiopathic dilated cardiomyopathy (DCM) has markedly improved during the last decade, mainly because of advancements in therapeutic strategies. However, sudden death still accounts for a significant part of the total mortality in patients with moderate disease. Recent primary prophylactic trials failed to demonstrate any benefit of cardioverter-defibrillator implantation in an unselected group of idiopathic DCM patients and thus the identification of the subgroup of patients at high arrhythmic risk is crucial. Although different risk stratification methods have been evaluated in risk assessment, the reported clinical value differs in studies, mainly because of differences in either methodology and/or patient selection. The present review focuses on arrhythmic events in idiopathic DCM and on the value of noninvasive methods and electrophysiological study in the risk stratification of this group of patients.
Assuntos
Arritmias Cardíacas/etiologia , Cardiomiopatia Dilatada/etiologia , Arritmias Cardíacas/classificação , Arritmias Cardíacas/epidemiologia , Barorreflexo/fisiologia , Cardiomiopatia Dilatada/epidemiologia , Cardiomiopatia Dilatada/fisiopatologia , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Técnicas Eletrofisiológicas Cardíacas , Frequência Cardíaca/fisiologia , Humanos , Incidência , Fatores de Risco , Volume Sistólico/fisiologia , Disfunção Ventricular/epidemiologia , Disfunção Ventricular/etiologia , Disfunção Ventricular/fisiopatologiaRESUMO
The term atrial flutter was introduced 90 years ago for an arrhythmia with a unique electrocardiographic pattern. The development of endocardial mapping techniques in the last decade allowed the detailed characterization of the tachycardia circuit and the identification of the cavotricuspid isthmus as its critical part. This review stresses the position of atrial flutter in the new classification of atrial tachycardias and focuses on its unique electrophysiological characteristics and different variants described in humans. Transcatheter radiofrequency ablation across the cavotricuspid isthmus constitutes a feasible and safe therapy, which prevents flutter recurrences during the long-term follow-up. This paper describes the different techniques that validate bidirectional isthmus block, which is an important endpoint for successful ablation.
Assuntos
Flutter Atrial/cirurgia , Arritmias Cardíacas/classificação , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/cirurgia , Flutter Atrial/classificação , Flutter Atrial/fisiopatologia , Ablação por Cateter , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , HumanosRESUMO
BACKGROUND: Low-energy internal cardioversion (LEIC) is a safe and effective procedure for the restoration of sinus rhythm in patients with atrial fibrillation refractory to external cardioversion. However, the procedure needs fluoroscopy and the use of the electrophysiology laboratory, even when the esophageal approach is utilized. The aim of this study was to assess the efficacy, safety and tolerability of a new simplified procedure of esophageal LEIC performed without fluoroscopy, outside the electrophysiology laboratory. METHODS: Thirty consecutive patients (23 males, 7 females) with persistent atrial fibrillation were submitted to LEIC using a step-up protocol (by steps of 50 V, starting from 200 V). Twenty (66%) were resistant to external cardioversion. A large surface area lead (cathode) was positioned within the esophagus, 45 cm from the nasal orifice. A second large surface area lead (anode) was positioned in the right atrium via the right internal jugular vein without fluoroscopic control. Synchronization of delivery of the shock with the QRS was achieved by means of two cutaneous electrodes positioned on the thoracic wall. RESULTS: Sinus rhythm was restored in 28 patients (93%) with a mean delivered energy of 15.2 +/- 7.5 J (range 5-27 J) and a mean impedance of 48.3 +/- 5.6 Ohm. No complication occurred during and after the procedure that was well tolerated under sedation. CONCLUSIONS: This new technique of performing esophageal LEIC is effective and seems to be safe and well tolerated. In this way internal cardioversion can be performed without fluoroscopy, outside the electrophysiology laboratory.
Assuntos
Fibrilação Atrial/terapia , Cardioversão Elétrica , Técnicas Eletrofisiológicas Cardíacas , Idoso , Ecocardiografia , Impedância Elétrica , Eletrocardiografia , Esôfago/patologia , Feminino , Fluoroscopia , Seguimentos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Resultado do TratamentoRESUMO
Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common regular narrow QRS tachycardias. Although the principal understanding of the physiology of dual atrioventricular conduction as a substrate for the reentry mechanism in AVNRT has not changed during the last 25 years, there is still some uncertainty with regard to the exact circuit delineation. At least four forms of AVNRT have been described and several possible circuits have been proposed. Although the refinement of our knowledge about AVNRT seems to be purely academic since further insight will probably not increase the success rate of treatment by radiofrequency catheter ablation, AVNRT continues to puzzle both clinical and basic electrophysiologists. The authors summarize our present knowledge about AVNRT and stress the unique features of the atrioventricular junction anatomy and the current opinions on the reentrant impulse propagation.
Assuntos
Taquicardia por Reentrada no Nó Atrioventricular/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/diagnóstico por imagem , Sistema de Condução Cardíaco/patologia , Humanos , Modelos Anatômicos , Taquicardia por Reentrada no Nó Atrioventricular/patologia , UltrassonografiaRESUMO
One challenge encountered during catheter ablation of postinfarction ventricular tachycardia (VT) is the inducibility of multiple VT morphologies associated with variable hemodynamic instability. The clinical usefulness and safety of a three-dimensional electroanatomical mapping in guiding radiofrequency (RF) catheter ablation of VT, used in parallel with a multichannel recording system, was studied in 28 men (mean age = 63.8 +/- 10.6 years, mean left ventricular ejection fraction = 28% +/- 9%). Three-dimensional voltage maps of the left ventricle were obtained in sinus rhythm with annotation of areas of fractionated or late potentials, zones of slow conduction and/or dense scar with no pacing capture at 10 mA. RF lesions were created either in sinus rhythm or during hemodynamically stable VT within reconstructed critical zones of the circuit. A total of 82 VTs were induced (mean = 2.9 +/- 1.0/patient). Hemodynamically unstable clinical VTs were induced in 5 patients, and clinical or nonclinical unstable VT in 14. Clinical VT was rendered noninducible in 24/28 (85.7%) patients, and monomorphic VT was eliminated in 16/28 (57.1%) patients. The mean procedural time was 258 +/- 82 minutes, and fluoroscopic exposure 13.5 +/- 8.8 minutes. During a mean follow-up period of 10.6 +/- 6.4 months, catheter ablation was repeated in 6 patients for VT recurrences. No significant complications occurred except for a transient cerebral ischemic attack in one patient. In conclusion, electroanatomical mapping assisted the successful and safe catheter ablation of both mappable and nonmappable VTs in a significant proportion of patients after myocardial infarction.