RESUMO
INTRODUCTION: Atrial fibrillation (AF) ablation is successful in 60%-80% of optimal candidates, with many patients requiring repeat procedures. We performed a detailed examination of electrophysiologic findings and clinical outcomes associated with first repeat AF ablations in the era of contact force-sensing radiofrequency (RF) catheters. METHODS: We retrospectively studied patients who underwent their first repeat AF ablations for symptomatic, recurrent AF at our center between 2013 and 2019. All repeat ablations were performed using contact force-sensing RF catheters. Pulmonary vein (PV) reconnections at repeat ablation and freedom from atrial arrhythmia 1 year after repeat ablation were evaluated. We further assessed these findings based on AF classification at the time of presentation for repeat ablation, index RF versus cryoballoon (CB) ablation, and duration (≥3 versus <3 years) between index and repeat procedures. RESULTS: Among 300 patients, there were 136 (45.3%) who presented for their first repeat ablations in persistent AF. During repeat ablation, at least one PV reconnection was found in 257 (85.6%) patients, while 159 (53%) had three to four reconnections. There was a similar distribution of reconnections among patients with persistent versus paroxysmal AF (mean: 2.7 ± 1.3 vs. 2.9 ± 1.2; p = .341), index RF versus CB ablation (mean: 2.8 ± 1.3 vs. 2.9 ± 1.2; p = .553), and ≥3 versus <3 years between index and repeat procedures (mean: 3.0 ± 1.1 vs. 2.7 ± 1.3; p = .119). At repeat ablation, the PVs were re-isolated in all patients, and additional non-PV ablation was performed in 171 (57%) patients. Freedom from atrial arrhythmia at 1-year follow-up after repeat ablation was 66%, similar among those with persistent versus paroxysmal AF (65.4% vs. 66.5%; p = .720), index RF versus CB ablation (66.7% vs. 68.9%; p = .930), and ≥3 versus <3 years between index and repeat ablations (64.4% vs. 66.7%; p = .760). Major complications occurred in a total of 4 (1.3%) patients. CONCLUSION: In a contemporary cohort of patients receiving their first repeat AF ablations using contact force-sensing RF catheters, PV reconnections were common, and freedom from atrial arrhythmia was 66% at 1-year follow-up. The distributions of PV reconnections and rates of freedom from atrial arrhythmia were similar, based on persistent versus paroxysmal AF at presentation for repeat ablation, index RF versus CB ablation, and duration between index and repeat procedures. The incidence of major complications was very low.
Assuntos
Fibrilação Atrial , Ablação por Cateter , Criocirurgia , Veias Pulmonares , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Humanos , Veias Pulmonares/cirurgia , Recidiva , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
INTRODUCTION: Advanced interatrial block (IAB) on a 12-lead electrocardiogram (ECG) is a predictor of stroke, incident atrial fibrillation (AF), and AF recurrence after catheter ablation. The objective of this study was to determine which features of IAB structural remodeling is associated with left atrium (LA) magnetic resonance imaging structure and function. METHODS/RESULTS: We included 152 consecutive patients (23% nonparoxysmal AF) who underwent preprocedural ECG and cardiac magnetic resonance (CMR) in sinus rhythm before catheter ablation of AF. IAB was defined as P-wave duration ≥120 ms, and was considered partial if P-wave was positive and advanced if P-wave had a biphasic morphology in inferior leads. From cine CMR and late gadolinium enhancement, we derived LA maximum and minimum volume indices, strain, LA fibrosis, and LA dyssynchrony. A total of 77 patients (50.7% paroxysmal) had normal P-wave, 52 (34.2%) partial IAB, and 23 (15.1%) advanced IAB. Patients with advanced IAB had significantly higher LA minimum volume index (25.7 vs 19.9 mL/m2 , P = .010), more LA fibrosis (21.9% vs 13.1%, P = .020), and lower LA maximum strain rate (0.99 vs 1.18, P = .007) than those without. Advanced IAB was independently associated with LA (minimum [P = .032] and fibrosis [P = .009]). P-wave duration was also independently associated with LA fibrosis (ß = .33; P = .049) and LA mechanical dyssynchrony (ß = 2.01; P = .007). CONCLUSION: Advanced IAB is associated with larger LA volumes, lower emptying fraction, and more fibrosis. Longer P-wave duration is also associated with more LA fibrosis and higher LA mechanical dyssynchrony.
Assuntos
Fibrilação Atrial , Bloqueio Interatrial , Idoso , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Fibrilação Atrial/diagnóstico por imagem , Meios de Contraste , Eletrocardiografia , Feminino , Fibrose , Gadolínio , Átrios do Coração/diagnóstico por imagem , Humanos , Bloqueio Interatrial/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Pacemaker battery depletion triggers alert for replacement notification and results in automatic reprogramming, which has been shown to be associated with relevant cardiorespiratory symptoms and adverse clinical events. OBJECTIVE: Determine if electrocardiogram (ECG) pacing features may be predictive of pacemaker battery depletion and clinical risk. METHODS: This is an ECG substudy of a cohort analysis of 298 subjects referred for pacemaker generator replacement from 2006 to 2017. Electronic medical record review was performed; clinical, ECG, and pacemaker characteristics were abstracted. We applied two ECG prediction rules for pacemaker battery depletion that are relevant to all major pacemaker manufacturers except Boston Scientific and MicroPort: (1) atrial pacing not at a multiple of 10 and (2) nonsynchronous ventricular pacing not at a multiple of 10, to determine diagnostic sensitivity, specificity, and risk in applicable ECG subjects. RESULTS: We excluded 32 subjects not at replacement notification or duplicate surgeries. Overall, 176 of 266 subjects (66.2%) demonstrated atrial pacing or nonsynchronous ventricular pacing on preoperative ECG. When utilizing both rules, 139 of 176 preoperative ECGs and 12 of 163 postoperative ECGs met criteria for battery depletion yielding reasonable sensitivity (79.0%), high specificity (92.6%), and a positive likelihood ratio of 11.6:1. These rules were associated with significant increase in cardiorespiratory symptoms (P < .001) and adverse clinical events (P < .025). CONCLUSIONS: The "Rules of Ten" provided reasonable sensitivity and specificity for detecting replacement notification in pacemaker subjects with an applicable ECG. This ECG tool may help clinicians identify most patients with pacemaker battery depletion at significant clinical risk.
Assuntos
Fontes de Energia Elétrica , Eletrocardiografia/métodos , Falha de Equipamento , Marca-Passo Artificial , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Ablation of atrial vagal ganglia has been associated with improved pulmonary vein isolation (PVI) outcomes. Disruption of vagal reflexes results in heart rate (HR) increase. We investigated the association between HR change after PVI and freedom from atrial fibrillation (AF) at 1 year. METHODS AND RESULTS: Patients who underwent PVI for paroxysmal AF were identified from the Johns Hopkins Hospital AF registry. Electrocardiograms taken pre-PVI and post-PVI were used to determine the change in HR. Patients followed-up at 3, 6, and 12 months. Of 257 patients (66% male, age 59+/-11 years), 134 (52%) remained free from AF at 1 year. The average HR increased from 60.6 ± 11.3 beats per minute (bpm) pre-PVI to 70.7 ± 12.0 bpm post-PVI. Patients with recurrence of AF had lower post-PVI HR than those who remained free from AF (67.8 ± 0.2 vs 73.3 ± 13.0 bpm; P <.001). The probability of AF recurrence at 1-year decreased as the change in HR increased (estimated odds ratio [OR], 0.83; 95% confidence interval [CI, 0.74-0.93]; P = .002). HR increase more than 15 bpm was associated with the lowest odds of AF recurrence (estimated OR, 0.39; 95% [0.17-0.85]; P = .018) compared to HR decrease. CONCLUSIONS: Resting HR was found to increase after PVI. Increase in HR more than 15 bpm has a positive association with remaining free from atrial fibrillation at 1 year.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Criocirurgia , Gânglios Parassimpáticos/cirurgia , Frequência Cardíaca , Veias Pulmonares/cirurgia , Nervo Vago/cirurgia , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Criocirurgia/efeitos adversos , Intervalo Livre de Doença , Feminino , Gânglios Parassimpáticos/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Veias Pulmonares/inervação , Recidiva , Reflexo , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Nervo Vago/fisiopatologiaRESUMO
INTRODUCTION: Catheter ablation is common for patients with symptomatic, drug-refractory atrial fibrillation (AF). Obesity is a known risk factor for incident AF. The impact of obesity on AF ablation outcomes is incompletely understood. We sought to determine the impact of elevated body mass index (BMI) on pulmonary vein isolation (PVI) procedural outcomes and associated complications. METHODS AND RESULTS: We evaluated patients undergoing PVI from 2001 to 2015, dividing them into four groups: normal weight (BMI ≥ 18.5 to < 25), overweight (BMI ≥ 25 to < 30), obese (BMI > 30 to < 40), and morbidly obese (BMI ≥ 40). Demographic and procedural characteristics, complications, and ablation outcomes were compared among groups. A total of 701 patients (146 time-matched controls, 227 overweight, 244 obese, and 84 morbidly obese) with complete demographic, procedural, and follow-up data were included. Increasing BMI correlated positively with HTN, OSA, CHA2 DS2 -VASC score, and persistent AF (P ≤ 0.001 for all associations). Radiofrequency application time and intraprocedural heparin dose increased with BMI (P ≤ 0.001). Arrhythmia recurrence at 1 year was 39.9% in controls, while higher in all high-BMI groups (overweight, 51.3%; obese, 57%; morbidly obese, 58.1 %; P = 0.007 for all versus controls). Impact of BMI on AF recurrence was not seen in persistent AF patients. Complication rates across groups were similar. CONCLUSIONS: AF recurrence after catheter ablation is higher in overweight, obese, and morbidly obese patients comparing to normal-weight controls, driven primarily by outcomes differences in paroxysmal AF patients. Complications were not associated with increased BMI.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Criocirurgia/efeitos adversos , Obesidade/complicações , Sobrepeso/complicações , Veias Pulmonares/cirurgia , Potenciais de Ação , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Índice de Massa Corporal , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Sobrepeso/diagnóstico , Veias Pulmonares/fisiopatologia , Recidiva , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Aims: The optimal site for biventricular endocardial (BIVENDO) pacing remains undefined. Acute haemodynamic response (AHR) is reproducible marker of left ventricular (LV) contractility, best expressed as the change in the maximum rate of LV pressure (LV-dp/dtmax), from a baseline state. We examined the relationship between factors known to impact LV contractility, whilst delivering BIVENDO pacing at a variety of LV endocardial (LVENDO) locations. Methods and results: We compiled a registry of acute LVENDO pacing studies from five international centres: Johns Hopkins-USA, Bordeaux-France, Eindhoven-The Netherlands, Oxford-United Kingdom, and Guys and St Thomas' NHS Foundation Trust, London-UK. In all, 104 patients incorporating 687 endocardial and 93 epicardial pacing locations were studied. Mean age was 66 ± 11 years, mean left ventricular ejection fraction 24.6 ± 7.7% and mean QRS duration of 163 ± 30 ms. In all, 50% were ischaemic [ischaemic cardiomyopathy (ICM)]. Scarred segments were associated with worse haemodynamics (dp/dtmax; 890 mmHg/s vs. 982 mmHg/s, P < 0.01). Delivering BiVENDO pacing in areas of electrical latency was associated with greater improvements in AHR (P < 0.01). Stimulating late activating tissue (LVLED >50%) achieved greater increases in AHR than non-late activating tissue (LVLED < 50%) (8.6 ± 9.6% vs. 16.1 ± 16.2%, P = 0.002). However, the LVENDO pacing location with the latest Q-LV, was associated with the optimal AHR in just 62% of cases. Conclusions: Identifying viable LVENDO tissue which displays late electrical activation is crucial to identifying the optimal BiVENDO pacing site. Stimulating late activating tissue (LVLED >50%) yields greater improvements in AHR however, the optimal location is frequently not the site of latest activation.
Assuntos
Potenciais de Ação , Terapia de Ressincronização Cardíaca/métodos , Endocárdio/fisiopatologia , Insuficiência Cardíaca/terapia , Frequência Cardíaca , Ventrículos do Coração/fisiopatologia , Contração Miocárdica , Disfunção Ventricular Esquerda/terapia , Função Ventricular Esquerda , Idoso , Europa (Continente) , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação , Sistema de Registros , Fatores de Tempo , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Pressão VentricularRESUMO
Aims: Historical studies of ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) have shown high long-term success rates and low complication rates. The potential impact of several recent practice trends has not been described. This study aims to characterize recent clinical practice trends in AVNRT ablation and their associated success rates and complications. Methods and results: Patients undergoing initial ablation of AVNRT between 1 July 2005 and 30 June 2015 were included in this study. Patient demographics and procedural data were abstracted from procedure reports. Follow-up data, including AVNRT recurrence and complications, was evaluated through electronic medical record review. In total, 877 patients underwent catheter ablation for AVNRT. By the last recorded year, three-dimension (3D) electroanatomical mapping (EAM) was used in 36.2%, 43.2% included anaesthesia, and 23.1% utilized irrigated catheters. Long-term procedural success was 95.5%. The use of anaesthesia, 3D EAM, and irrigated ablation catheters were not associated with differences in success. The presence of an atrial 'echo' or 'AH' jump at the end of an acutely successful procedure was not associated with long-term recurrence (P = 0.18, P = 0.15, respectively). Complications, including AV block requiring a pacemaker (0.4%), were uncommon. Conclusion: In a large, contemporary cohort, catheter ablation for AVNRT remains highly successful with low complications rates. The increased use of anaesthesia as well as modern mapping and ablation tools were not associated with changes in clinical outcomes. Further prospective evaluation of such contemporary practices is warranted given the lack of evidence to support their escalating use.
Assuntos
Ablação por Cateter , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Anestesia/métodos , Ablação por Cateter/efeitos adversos , Ablação por Cateter/tendências , Técnicas Eletrofisiológicas Cardíacas , Humanos , Complicações Pós-Operatórias/etiologia , Padrões de Prática Médica/tendências , Recidiva , Estudos Retrospectivos , Fatores de Risco , Taquicardia por Reentrada no Nó Atrioventricular/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Fluxo de TrabalhoRESUMO
BACKGROUND: Pacemaker patients experience battery depletion that activates pacemaker's alert for replacement notification. Automatic reprogramming at replacement notification can result in loss of rate response and atrioventricular (AV) synchrony. OBJECTIVE: To determine if relevant symptoms or clinical events may be associated with automatic reprogramming at replacement notification. METHODS: Electronic medical record review was undertaken for 298 patients referred for pacemaker generator replacement. Primary endpoints were symptoms or clinical events during replacement notification period. RESULTS: Following elimination of duplicate pacemaker replacements (n = 12), "near-replacement notification" or "recalled" (n = 15) and pacemakers at "end of life" (n = 5), 266 subjects were included. Three distinct reprogramming cohorts were identified; those with no change (control) in pacing mode (n = 46), those with loss of rate response (n = 154), and those with loss of AV synchrony ± rate response (n = 66). In total, 83 subjects (31.2%) had symptoms with significant differences seen between groups (control = 4.3%, loss of rate response = 26.0%, loss of AV synchrony ± rate response = 62.1%, P < 0.001). Overall, 28 subjects (10.5%) experienced clinical events with significant differences seen between groups (control = 0.0%, loss of rate response = 6.5%, loss of AV synchrony ± rate response = 27.3%, P < 0.001). CONCLUSIONS: Automatic reprogramming at replacement notification was associated with significant symptoms in 26% of those who lost rate response and in 62% of those who lost AV synchrony ± rate response. Additionally, 27% of the latter cohort required nonelective clinical care.
Assuntos
Fontes de Energia Elétrica , Marca-Passo Artificial , Idoso , Idoso de 80 Anos ou mais , Remoção de Dispositivo , Eletrodos Implantados , Falha de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de TempoRESUMO
BACKGROUND: Patients go without pacemaker, defibrillator, and cardiac resynchronization therapies (devices) each year due to the prohibitive costs of devices. OBJECTIVE: We sought to examine data available from studies regarding contemporary risks of reused devices in comparison with new devices. METHODS: We searched online indexing sites to identify recent studies. Peer-reviewed manuscripts reporting infection, malfunction, premature battery depletion, and device-related death with reused devices were included. The primary study outcome was the composite risk of infection, malfunction, premature battery depletion, and death. Secondary outcomes were the individual risks. RESULTS: Nine observational studies (published 2009-2017) were identified totaling 2,302 devices (2,017 pacemakers, 285 defibrillators). Five controlled trials were included in meta-analysis (2,114 devices; 1,258 new vs 856 reused). All device reuse protocols employed interrogation to confirm longevity and functionality, disinfectant therapy, and, usually, additional biocidal agents, packaging, and ethylene oxide gas sterilization. Demographic characteristics, indications for pacing, and median follow-up were similar. There were no device-related deaths reported and no statistically significant difference in risk between new versus reused devices for the primary outcome (2.23% vs 3.86% respectively, P = 0.807, odds ratio = 0.76). There were no significant differences seen in the secondary outcomes for the individual risks of infection, malfunction, and premature battery depletion. CONCLUSIONS: Device reuse utilizing modern protocols did not significantly increase risk of infection, malfunction, premature battery depletion, or device-related death in observational studies. These data provide rationale for proceeding with a prospective multicenter noninferiority randomized control trial.
Assuntos
Desfibriladores Implantáveis , Reutilização de Equipamento , Marca-Passo Artificial , Remoção de Dispositivo , Falha de Equipamento , Humanos , Fatores de RiscoRESUMO
The mechanism of atrial fibrillation (AF) maintenance in humans is yet to be determined. It remains controversial whether cardiac fibrillatory dynamics are the result of a deterministic or a stochastic process. Traditional methods to differentiate deterministic from stochastic processes have several limitations and are not reliably applied to short and noisy data obtained during clinical studies. The appearance of missing ordinal patterns (MOPs) using the Bandt-Pompe (BP) symbolization is indicative of deterministic dynamics and is robust to brief time series and experimental noise. Our aim was to evaluate whether human AF dynamics is the result of a stochastic or a deterministic process. We used 38 intracardiac atrial electrograms during AF from the coronary sinus of 10 patients undergoing catheter ablation of AF. We extracted the intervals between consecutive atrial depolarizations (AA interval) and converted the AA interval time series to their BP symbolic representation (embedding dimension 5, time delay 1). We generated 40 iterative amplitude-adjusted, Fourier-transform (IAAFT) surrogate data for each of the AA time series. IAAFT surrogates have the same frequency spectrum, autocorrelation, and probability distribution with the original time series. Using the BP symbolization, we compared the number of MOPs and the rate of MOP decay in the first 1000 timepoints of the original time series with that of the surrogate data. We calculated permutation entropy and permutation statistical complexity and represented each time series on the causal entropy-complexity plane. We demonstrated that (a) the number of MOPs in human AF is significantly higher compared to the surrogate data (2.7 ± 1.18 vs. 0.39 ± 0.28, p < 0.001); (b) the median rate of MOP decay in human AF was significantly lower compared with the surrogate data (6.58 × 10-3 vs. 7.79 × 10-3, p < 0.001); and (c) 81.6% of the individual recordings had a rate of decay lower than the 95% confidence intervals of their corresponding surrogates. On the causal entropy-complexity plane, human AF lay on the deterministic part of the plane that was located above the trajectory of fractional Brownian motion with different Hurst exponents on the plane. This analysis demonstrates that human AF dynamics does not arise from a rescaled linear stochastic process or a fractional noise, but either a deterministic or a nonlinear stochastic process. Our results justify the development and application of mathematical analysis and modeling tools to enable predictive control of human AF.
Assuntos
Algoritmos , Fibrilação Atrial/fisiopatologia , Entropia , Eletrocardiografia , Humanos , Processamento de Sinais Assistido por Computador , Processos EstocásticosRESUMO
Aims: Complications from catheter ablation for atrial fibrillation (AF) are well described. Changing aspects of AF ablation including patient populations referred, institutional experience, and emerging catheter and pharmacological options may impact complication rates. We assessed procedural complication trends in AF ablation patients from 20032015 to identify what factors affect adverse event rates. Methods and Results: We evaluated consecutively enrolled patients undergoing initial AF ablation from 2003 through 2015. Statistical analyses were performed to identify predictors of increased risk for major complications, which were defined as death, stroke, atrio-oesophageal fistula, phrenic nerve injury, cardiovascular events requiring blood transfusions or procedural interventions, or non-cardiovascular events requiring intervention. A total of 1475 patients (mean age 59.5 ± 10.5, 82% male) were evaluated. Major complications occurred in 3.9% (n = 58) of cases, including vascular access-site haematoma (1.3%), cardiac tamponade (1.1%), and cerebrovascular accident (CVA) (0.9%). Univariate analysis revealed increased risk of complications associated with hypertension (P = 0.048), CHA2DS2VASc score ≥1 (P = 0.015), and early institutional experience (P = 0.003). Populations with higher CHA2DS2VASc scores underwent AF ablation more frequently over time (P < 0.001). Novel catheters and anticoagulants did not appreciably affect complication rates. Multivariate analysis adjusting for hypertension, CHA2DS2VASc score, and institutional experience showed that higher CHA2DS2VASc score and early institutional experience were independent predictors of adverse events. Conclusion: Patient characteristics reflected in CHA2DS2VASc scoring and early institutional experience predict increased complication rates following AF ablation. Despite more patients with higher CHA2DS2VASc scores undergoing AF ablation, complication rates fell over time as institutional experience increased.
Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Fístula Esofágica/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Idoso , Transfusão de Sangue/estatística & dados numéricos , Tamponamento Cardíaco/epidemiologia , Doenças Cardiovasculares/epidemiologia , Feminino , Átrios do Coração , Cardiopatias/epidemiologia , Hematoma/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade , Análise Multivariada , Nervo Frênico/lesões , Complicações Pós-Operatórias/terapia , Fatores de Risco , Acidente Vascular Cerebral/epidemiologiaRESUMO
All contemporary pacemakers undergo automatic reprogramming upon reaching elective replacement indication due to battery depletion. The majority of such reprogramming will result in changes to both pacing mode and pacing rate. The exact software reprogramming varies considerably among pacemaker manufacturers and may even vary among models of the same manufacturer. Accordingly, it is essential for healthcare providers managing pacemaker patients to have a detailed understanding of the automatic reprogramming seen at elective replacement indication as well as their potential physiological and clinical consequences.
Assuntos
Fontes de Energia Elétrica , Marca-Passo Artificial , HumanosRESUMO
INTRODUCTION: The interplay between electrical activation and mechanical contraction patterns is hypothesized to be central to reduced effectiveness of cardiac resynchronization therapy (CRT). Furthermore, complex scar substrates render CRT less effective. We used novel cardiac computed tomography (CT) and noninvasive electrocardiographic imaging (ECGI) techniques in an ischemic dyssynchronous heart failure (DHF) animal model to evaluate electrical and mechanical coupling of cardiac function, tissue viability, and venous accessibility of target pacing regions. METHODS AND RESULTS: Ischemic DHF was induced in 6 dogs using coronary occlusion, left bundle ablation and tachy RV pacing. Full body ECG was recorded during native rhythm followed by volumetric first-pass and delayed enhancement CT. Regional electrical activation were computed and overlaid with segmented venous anatomy and scar regions. Reconstructed electrical activation maps show consistency with LBBB starting on the RV and spreading in a "U-shaped" pattern to the LV. Previously reported lines of slow conduction are seen parallel to anterior or inferior interventricular grooves. Mechanical contraction showed large septal to lateral wall delay (80 ± 38 milliseconds vs. 123 ± 31 milliseconds, P = 0.0001). All animals showed electromechanical correlation except dog 5 with largest scar burden. Electromechanical decoupling was largest in basal lateral LV segments. CONCLUSION: We demonstrated a promising application of CT in combination with ECGI to gain insight into electromechanical function in ischemic dyssynchronous heart failure that can provide useful information to study regional substrate of CRT candidates.
Assuntos
Arritmias Cardíacas/diagnóstico por imagem , Mapeamento Potencial de Superfície Corporal , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/diagnóstico por imagem , Frequência Cardíaca , Contração Miocárdica , Infarto do Miocárdio/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Potenciais de Ação , Animais , Arritmias Cardíacas/patologia , Arritmias Cardíacas/fisiopatologia , Fenômenos Biomecânicos , Modelos Animais de Doenças , Cães , Sistema de Condução Cardíaco/patologia , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Valor Preditivo dos Testes , Sobrevivência de TecidosRESUMO
AIMS: Electromechanical de-coupling is hypothesized to explain non-response of dyssynchrony patient to cardiac resynchronization therapy (CRT). In this pilot study, we investigated regional electromechanical uncoupling in 10 patients referred for CRT using two non-invasive electrical and mechanical imaging techniques (CMR tissue tracking and ECGI). METHODS AND RESULTS: Reconstructed regional electrical and mechanical activation captured delayed LBBB propagation direction from septal to anterior/inferior and finally to lateral walls as well as from LV apical to basal. All 5 responders demonstrated significantly delayed mechanical and electrical activation on the lateral LV wall at baseline compared to the non-responders (P<.05). On follow-up ECGI, baseline electrical activation patterns were preserved in native rhythm and global LV activation time was reduced with biventricular pacing. CONCLUSIONS: The combination of novel imaging techniques of ECGI and CMR tissue tracking can be used to assess spatial concordance of LV electrical and mechanical activation to gain insight into electromechanical coupling.
Assuntos
Técnicas de Imagem Cardíaca/métodos , Ecocardiografia/métodos , Imagem Cinética por Ressonância Magnética/métodos , Técnica de Subtração , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/prevenção & controle , Algoritmos , Terapia de Ressincronização Cardíaca/métodos , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Software , Volume Sistólico , Disfunção Ventricular Esquerda/terapiaRESUMO
BACKGROUND: The novel oral anticoagulants (NOACs) are used for stroke prevention in atrial fibrillation (AF), but their safety and efficacy in the periablation period are not well established. Additionally, no standard procedure for managing periprocedural and intraprocedural anticoagulation has been established. OBJECTIVE: To evaluate the frequency of hemorrhagic and thrombotic events as well as periprocedural management strategies of NOACs compared with warfarin as anticoagulation therapy for AF ablation. METHODS: This was a retrospective cohort study from a prospective AF ablation registry maintained at a large, academic medical center. RESULTS: A total of 374 cases (173 warfarin, 123 dabigatran, 61 rivaroxaban, and 17 apixaban) were included in the analysis. The overall hemorrhagic/thrombotic event rate was 14.2 % (major hemorrhage 2.7%, minor hemorrhage 11.2%, thrombotic stroke 0.5%). The frequency of minor hemorrhage was significantly higher with warfarin compared with dabigatran (15% vs 5.7%, P = 0.012). The average heparin dose required to reach the goal activated clotting time (ACT) was 5600 units for warfarin, 12 900 units for dabigatran (P < 0.001), 15 100 units for rivaroxaban (P < 0.001), and 14 700 units for apixaban (P < 0.001). The average time in minutes to reach the goal ACT was significantly longer, compared with warfarin, for dabigatran (57 vs 28, P < 0.001), rivaroxaban (63 vs 28, P < 0.001), and apixaban (72 vs 28, P < 0.001). CONCLUSIONS: Compared with warfarin, periprocedural anticoagulation with dabigatran resulted in fewer minor hemorrhages and total adverse events after AF ablation. Patients anticoagulated with NOACs required larger doses of heparin and took longer to reach the goal ACT compared with patients anticoagulated with warfarin.
Assuntos
Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Ablação por Cateter , Varfarina , Administração Oral , Idoso , Benzimidazóis/administração & dosagem , Benzimidazóis/efeitos adversos , Ablação por Cateter/efeitos adversos , Dabigatrana , Esquema de Medicação , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Morfolinas/administração & dosagem , Morfolinas/efeitos adversos , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Estudos Retrospectivos , Rivaroxabana , Acidente Vascular Cerebral/prevenção & controle , Tiofenos/administração & dosagem , Tiofenos/efeitos adversos , Resultado do Tratamento , Varfarina/administração & dosagem , Varfarina/efeitos adversos , beta-Alanina/administração & dosagem , beta-Alanina/efeitos adversos , beta-Alanina/análogos & derivadosRESUMO
Background: Atrial fibrillation (AF) patients are at high risk of stroke with â¼90% clots originating from the left atrial appendage (LAA). Clinical understanding of blood-flow based parameters and their potential association with stroke for AF patients remains poorly understood. We hypothesize that slow blood-flow either in the LA or the LAA could lead to the formation of blood clots and is associated with stroke for AF patients. Methods: We retrospectively collected cardiac CT images of paroxysmal AF patients and dichotomized them based on clinical event of previous embolic event into stroke and non-stroke groups. After image segmentation to obtain 3D LA geometry, patient-specific blood-flow analysis was performed to model LA hemodynamics. In terms of geometry, we calculated area of the pulmonary veins (PVs), mitral valve, LA and LAA, orifice area of LAA and volumes of LA and LAA and classified LAA morphologies. For hemodynamic assessment, we quantified blood flow velocity, wall shear stress (WSS, blood-friction on LA wall), oscillatory shear index (OSI, directional change of WSS) and endothelial cell activation potential (ECAP, ratio of OSI and WSS quantifying slow and oscillatory flow) in the LA as well as the LAA. Statistical analysis was performed to compare the parameters between the groups. Results: Twenty-seven patients were included in the stroke and 28 in the non-stroke group. Examining geometrical parameters, area of left inferior PV was found to be significantly higher in the stroke group as compared to non-stroke group (p = 0.026). In terms of hemodynamics, stroke group had significantly lower blood velocity (p = 0.027), WSS (p = 0.018) and higher ECAP (p = 0.032) in the LAA as compared to non-stroke group. However, LAA morphologic type did not differ between the two groups. This suggests that stroke patients had significantly slow and oscillatory circulating blood-flow in the LAA, which might expose it to potential thrombogenesis. Conclusion: Slow flow in the LAA alone was associated with stroke in this paroxysmal AF cohort. Patient-specific blood-flow analysis can potentially identify such hemodynamic conditions, aiding in clinical stroke risk stratification of AF patients.
RESUMO
Atrial fibrillation (AF), the most common heart rhythm disorder, may cause stroke and heart failure. For patients with persistent AF with fibrosis proliferation, the standard AF treatment-pulmonary vein isolation-has poor outcomes, necessitating redo procedures, owing to insufficient understanding of what constitutes good targets in fibrotic substrates. Here we present a prospective clinical and personalized digital twin study that characterizes the arrhythmogenic properties of persistent AF substrates and uncovers locations possessing rotor-attracting capabilities. Among these, a portion needs to be ablated to render the substrate not inducible for rotors, but the rest (37%) lose rotor-attracting capabilities when another location is ablated. Leveraging digital twin mechanistic insights, we suggest ablation targets that eliminate arrhythmia propensity with minimum lesions while also minimizing the risk of iatrogenic tachycardia and AF recurrence. Our findings provide further evidence regarding the appropriate substrate ablation targets in persistent AF, opening the door for effective strategies to mitigate patients' AF burden.
RESUMO
BACKGROUND: Patients commonly present for atrial fibrillation (AF) ablation while taking antiarrhythmic (AA) medications. It is unknown if AA use at the time of ablation affects procedural outcome. This study compares the AF ablation outcomes of patients who underwent ablation while on AA medications to those who were not on AA medications. METHODS AND RESULTS: A total of 180 consecutive patients who underwent their first catheter ablation of AF were identified from the Johns Hopkins Hospital AF registry and divided into 2 cohorts: those On AA at the time of ablation (127 patients, mean follow-up 24.6 months) and those Off AA at the time of ablation (53 patients, mean follow-up 20.3 months). Follow-up was performed to identify recurrent AF. There was no statistically significant difference in the percentage of patients without a recurrence of symptomatic AF (single procedure success rate) in the On and Off AA groups at 6 months postablation (53.5% vs 50.1%, P = 0.75), or by the end of follow-up (37.8% vs 41.5%, P = 0.64). For those patients who had symptomatic AF recurrence, the average time to recurrence was 6.2 ± 9.0 months in the On AA group and 4.2 ± 7.2 months in the Off AA group (P = 0.27). CONCLUSIONS: There was no statistically significant difference in the rate of symptomatic AF recurrence between the On AA and Off AA groups in this study. The use of AA medications at the time of ablation does not appear to affect procedural outcomes in this population.
Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Distribuição de Qui-Quadrado , Terapia Combinada , Técnicas Eletrofisiológicas Cardíacas , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Estatísticas não Paramétricas , Taxa de Sobrevida , Resultado do TratamentoRESUMO
INTRODUCTION: High defibrillation threshold (DFT) is a clinical problem in 1-8% of implantable cardioverter-defibrillator implants. Some clinicians and investigators question whether the benefits of routine DFT testing outweigh the risks. Identification of the predictors of elevated DFT may allow selective application of DFT testing. However, the clinical characteristics of patients with high DFT in the modern era have not been well-defined. METHODS: All patients who underwent DFT testing in our institution during an 8-year period were reviewed for this retrospective study. High DFT was defined as less than a 10-J safety margin on initial testing. For each case, the two cases preceding and two cases following by the same implanter were selected as controls. RESULTS: Of the 2,138 patients who underwent DFT testing, 48 (2.2%) met criteria for high DFT. Compared to 192 control patients, patients with high DFT were more likely to be younger (P = 0.004), have nonischemic cardiomyopathy (P = 0.036), have a longer QRS interval (P = 0.026), and have a left ventricular ejection fraction (LVEF) ≤ 0.25 (P = 0.013). On multivariate analysis, only younger age (P = 0.016) and LVEF ≤ 0.25 (P = 0.010) remained statistically significant predictors of elevated DFT. CONCLUSIONS: High DFT was identified in 2.2% of ICD implants in our institution in recent years. Although younger age and depressed LVEF predicts this problem, elevated DFT occurred in patients of all ages and ejection fractions. Elimination of routine DFT testing appears to be premature given the prevalence and unpredictability of elevated DFT.