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BACKGROUND: Despite an increased incidence of chronic heart failure (HF) and sudden cardiac death (SCD), the use of implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) is much lower in Japan than in Western countries. The HF Indication and SCD Prevention Trial Japan (HINODE) prospectively assessed the mortality rate, appropriately treated ventricular arrhythmias (VA), and HF in Japanese patients with a higher risk of HF. METHODSâANDâRESULTS: HINODE consisted of ICD, CRT-defibrillator (CRT-D), pacing, and non-device treatment cohorts. This subanalysis evaluated the impact of the implantation of high-voltage devices (HVD; ICD and CRT-D) in 171 Japanese patients. We compared all-cause mortality, VA, and HF events between elderly (age >70 years at study enrollment) and non-elderly HVD recipients. The estimated survival rate through 24 months in the HVD cohort was 85.8% (97.5% lower control limit 77.6%). The risk of all-cause mortality was increased for the elderly vs. non-elderly (hazard ratio [HR] 2.82; 95% confidence interval [CI] 1.01-7.91; P=0.039), but did not differ after excluding ICD patients with CRT-D indication (HR 2.32; 95% CI 0.79-6.78; P=0.11). There were no differences in VA and HF event-free rates between elderly and non-elderly HVD recipients (P=0.73 and P=0.55, respectively). CONCLUSIONS: Although elderly patients may have a higher risk of mortality in general, the benefit of HVD therapy in this group is comparable to that in non-elderly patients.
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Terapia de Resincronización Cardíaca , Desfibriladores Implantables , Insuficiencia Cardíaca , Humanos , Anciano , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/terapia , Masculino , Femenino , Japón/epidemiología , Anciano de 80 o más Años , Persona de Mediana Edad , Prevención Primaria , Estudios Prospectivos , Muerte Súbita Cardíaca/prevención & control , Factores de Edad , Factores de Riesgo , Pueblos del Este de AsiaRESUMEN
The number of TV-PM implantations in elderly people is increasing. Although frailty syndrome is common in elderly patients, the relationship between the pre-procedural frailty status and clinical outcomes has not been fully elucidated in elderly TV-PM recipients.This study included 103 consecutive patients over 80 years old who were newly implanted with a TV-PM (age 85.7 ± 4.2, 41.7% male). We assessed the relationship between the clinical outcome and predictive factors, especially for the pre-procedural frailty status after the TV-PM implantation. The pre-procedural frailty status was retrospectively assessed from the medical records and classified on the basis of impairments in 3 domains (walking, cognition, and activities of daily living). The primary endpoint was defined as a heart failure admission.During the follow-up period (4.1 ± 2.3 years), 20 patients (19.4%) met the primary endpoint. Frailty syndrome was identified in 40 patients (38.8%). In univariate analysis, the LVEF (HR 0.97, 95% CI 0.96-1.00 P = 0.0492), an RV pacing burden over 40% (HR 1.58, 95% CI 1.00-2.54 P = 0.0473), and presence of a frailty status (HR 1.82, 95% CI 1.13-2.87 P = 0.0134) were found to be statistically significant predictors for the study endpoint. In multivariate analysis, having frailty syndrome was the only predictive factor for a heart failure admission (HR 1.83, 95% CI 1.12-2.93 P = 0.0157).The presence of frailty syndrome and incidence of clinical events were high and a pre-procedural frailty status assessment was key in determining the clinical outcomes in TV-PM recipients over 80 years old.
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Fragilidad , Insuficiencia Cardíaca , Marcapaso Artificial , Humanos , Masculino , Anciano , Anciano de 80 o más Años , Femenino , Fragilidad/epidemiología , Anciano Frágil , Estudios Retrospectivos , Actividades Cotidianas , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/terapiaRESUMEN
Myocardium baseline impedance (BI) is an important factor in ablation effectiveness. This study examined the performance of low-power and long-duration (LPLD), high-power and short-duration (HPSD) ablation at different BIs by computer simulation. A 3D model of the ablation region was constructed for simulation, and in vitro experiments were performed to validate the simulation. Three ablation power and duration configurations of 30 W/30 s, 50 W/10 s, and 90 W/5 s were used for simulation with BI values of 90, 100, 110, 120, 130, and 140 Ω. Roll-off time and ablation volume were measured to evaluate ablation results. The simulation is consistent with the in vitro experiments. When BI is changed from 90 [Formula: see text] to 140 [Formula: see text], the lesion volume over 50 °C with BI of 140 [Formula: see text] was reduced by 6.3%, 6.7%, and 7.3% for 30 W/30 s, 50 W/10 s, and 90 W/5 s configurations, respectively, and the lesion volume over 100 °C was reduced by 62.8%, 49.7%, and 22.5% under 30 W/30 s, 50 W/10 s, and 90 W/5 s, respectively. Simulation results revealed that HPSD (vHPSD) and LPLD ablation were more affected by changes in BI in the lesion volumes over 50 °C and 100 °C, respectively, and demonstrated that resistive and conductive heating were the main heating effects in HPSD (vHPSD) and LPLD, respectively.
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Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Humanos , Simulación por Computador , Impedancia Eléctrica , Ablación por Catéter/métodos , Miocardio/patología , Factores de Tiempo , Fibrilación Atrial/cirugía , Venas Pulmonares/cirugía , Resultado del TratamientoRESUMEN
INTRODUCTION: Data are lacking on the extent to which patients with non-valvular atrial fibrillation (AF) who are aged ≥80 years benefit from ablation treatment. The question pertains especially to patients' postablation quality of life (QoL) and long-term clinical outcomes. METHODS AND ANALYSIS: We are initiating a prospective, registry-based, multicentre observational study that will include patients aged ≥80 years with non-valvular AF who choose to undergo treatment by catheter ablation and, for comparison, such patients who do not choose to undergo ablation (either according to their physician's advice or their own preference). Study subjects are to be enrolled from 52 participant hospitals and three clinics located throughout Japan from 1 June 2022 to 31 December 2023, and each will be followed up for 1 year. The planned sample size is 660, comprising 220 ablation group patients and 440 non-ablation group patients. The primary endpoint will be the composite incidence of stroke/transient ischaemic attack (TIA) or systemic embolism (SE), another cardiovascular event, major bleeding and/or death from any cause. Other clinical events such as postablation AF recurrence, a fall or bone fracture will be recorded. We will collect standard clinical background information plus each patient's Clinical Frailty Scale score, AF-related symptoms, QoL (Five-Level Version of EQ-5D) scores, Mini-Mental State Examination (optional) score and laboratory test results, including measures of nutritional status, on entry into the study and 1 year later, and serial changes in symptoms and QoL will also be secondary endpoints. Propensity score matching will be performed to account for covariates that could affect study results. ETHICS AND DISSEMINATION: The study conforms to the Declaration of Helsinki and the Ethical Guidelines for Clinical Studies issued by the Ministry of Health, Labour and Welfare, Japan. Results of the study will be published in one or more peer-reviewed journals. TRIAL REGISTRATION NUMBER: UMIN000047023.
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Fibrilación Atrial , Ablación por Catéter , Accidente Cerebrovascular , Anciano , Humanos , Fibrilación Atrial/epidemiología , Fibrilación Atrial/cirugía , Fibrilación Atrial/complicaciones , Calidad de Vida , Estudios Prospectivos , Esperanza de Vida Saludable , Factores de Riesgo , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/complicaciones , Sistema de Registros , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Resultado del TratamientoRESUMEN
Heart failure (HF) is challenging public medical and healthcare systems. This study aimed to develop and validate a novel deep learning-based prognostic model to predict the risk of all-cause mortality for patients with HF. We also compared the performance of the proposed model with those of classical deep learning- and traditional statistical-based models. The present study enrolled 730 patients with HF hospitalized at Toho University Ohashi Medical Center between April 2016 and March 2020. A recurrent neural network-based model (RNNSurv) involving time-varying covariates was developed and validated. The proposed RNNSurv showed better prediction performance than those of a deep feed-forward neural network-based model (referred as "DeepSurv") and a multivariate Cox proportional hazard model in view of discrimination (C-index: 0.839 vs. 0.755 vs. 0.762, respectively), calibration (better fit with a 45-degree line), and ability of risk stratification, especially identifying patients with high risk of mortality. The proposed RNNSurv demonstrated an improved prediction performance in consideration of temporal information from time-varying covariates that could assist clinical decision-making. Additionally, this study found that significant risk and protective factors of mortality were specific to risk levels, highlighting the demand for an individual-specific clinical strategy instead of a uniform one for all patients.
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Identifying patient prognostic phenotypes facilitates precision medicine. This study aimed to explore phenotypes of patients with heart failure (HF) corresponding to prognostic condition (risk of mortality) and identify the phenotype of new patients by machine learning (ML). A unsupervised ML was applied to explore phenotypes of patients in a derivation dataset (n = 562) based on their medical records. Thereafter, supervised ML models were trained on the derivation dataset to classify these identified phenotypes. Then, the trained classifiers were further validated on an independent validation dataset (n = 168). Finally, Shapley additive explanations were used to interpret decision making of phenotype classification. Three patient phenotypes corresponding to stratified mortality risk (high, low, and intermediate) were identified. Kaplan−Meier survival curves among the three phenotypes had significant difference (pairwise comparison p < 0.05). Hazard ratio of all-cause mortality between patients in phenotype 1 (n = 91; high risk) and phenotype 3 (n = 329; intermediate risk) was 2.08 (95%CI 1.29−3.37, p = 0.003), and 0.26 (95%CI 0.11−0.61, p = 0.002) between phenotype 2 (n = 142; low risk) and phenotype 3. For phenotypes classification by random forest, AUCs of phenotypes 1, 2, and 3 were 0.736 ± 0.038, 0.815 ± 0.035, and 0.721 ± 0.03, respectively, slightly better than the decision tree. Then, the classifier effectively identified the phenotypes for new patients in the validation dataset with significant difference on survival curves and hazard ratios. Finally, age and creatinine clearance rate were identified as the top two most important predictors. ML could effectively identify patient prognostic phenotypes, facilitating reasonable management and treatment considering prognostic condition.
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OBJECTIVES: The goal of this study was to evaluate whether intermittent VNS reduces electrical heterogeneities and arrhythmia inducibility during sympathoexcitation. BACKGROUND: Sympathoexcitation increases the risk of ventricular tachyarrhythmias (VT). Vagal nerve stimulation (VNS) has been antiarrhythmic in the setting of ischemia-driven arrhythmias, but it is unclear if it can overcome the electrophysiological effects of sympathoexcitation in the setting of chronic myocardial infarction (MI). METHODS: In Yorkshire pigs after chronic MI, a sternotomy was performed, a 56-electrode sock was placed over the ventricles (n = 17), and a basket catheter was positioned in the left ventricle (n = 6). Continuous unipolar electrograms from sock and basket arrays were obtained to analyze activation recovery interval (ARI), a surrogate of action potential duration. Bipolar voltage mapping was performed to define scar, border zone, or viable myocardium. Hemodynamic and electrical parameters and VT inducibility were evaluated during sympathoexcitation with bilateral stellate ganglia stimulation (BSS) and during combined BSS with intermittent VNS. RESULTS: During BSS, global epicardial ARIs shortened from 384 ± 59 milliseconds to 297 ± 63 milliseconds and endocardial ARIs from 359 ± 36 milliseconds to 318 ± 40 milliseconds. Dispersion in ARIs increased in all regions, with the greatest increase observed in scar and border zone regions. VNS mitigated the effects of BSS on border zone ARIs (from -18.3% ± 6.3% to -2.1% ± 14.7%) and ARI dispersion (from 104 ms2 [1 to 1,108 ms2] to -108 ms2 [IQR: -588 to 30 ms2]). VNS reduced VT inducibility during sympathoexcitation (from 75%-40%; P < 0.05). CONCLUSIONS: After chronic MI, VNS overcomes the detrimental effects of sympathoexcitation by reducing electrophysiological heterogeneities exacerbated by sympathetic stimulation, decreasing VT inducibility.
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Infarto del Miocardio , Taquicardia Ventricular , Estimulación del Nervio Vago , Animales , Arritmias Cardíacas , Cicatriz , Corazón , Frecuencia Cardíaca/fisiología , Humanos , Infarto del Miocardio/complicaciones , Infarto del Miocardio/terapia , Porcinos , Taquicardia Ventricular/terapiaRESUMEN
AIM: Physiological tests to assess systemic vascular function are not included in the risk score for atrial fibrillation (AF). We aimed to examine whether cardio-ankle vascular index (CAVI), a systemic arterial stiffness parameter, is associated with the presence of AF in Japanese general population. METHODS: A cross-sectional study (N = 47,687) and a cohort study (N = 5418, four consecutive years) in Japanese urban residents who participated in annual health screening were conducted. RESULTS: A total of 164 subjects (0.34%) had AF in the cross-sectional data. After propensity score matching for age and gender, logistic regression analysis revealed that CAVI is independently associated with AF, as are body mass index and estimated glomerular filtration rate. In a 4-year cohort study, 22 subjects (0.41%) with new-appearance of AF showed higher CAVI at baseline than those without. In the receiver-operating-characteristic curve analysis, the area under the curve, which is a measure of predictability, of CAVI for the new-appearance of AF was 0.747, and the cut-off value of CAVI was 8.0. Kaplan-Meier analysis revealed that the cumulative incidence of new-appearance of AF was higher in subjects with CAVI ≥8.0 compared to those with CAVI <8.0. In Cox-proportional hazards analysis, CAVI ≥8.0 as well as gender were identified as independent predictors for the new-appearance of AF, whereas age ≥65 years was not. CONCLUSION: Increased CAVI may represent a major modifiable risk factor for the development of AF. Studies are needed to confirm that CAVI is a predictor of AF independent of various AF risk factors and that CAVI-lowering interventions can prevent new-appearance or recurrence of AF.
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Fibrilación Atrial , Rigidez Vascular , Anciano , Tobillo/irrigación sanguínea , Índice Tobillo Braquial , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Estudios de Cohortes , Estudios Transversales , Humanos , Japón/epidemiología , Prevalencia , Estudios Retrospectivos , Población UrbanaRESUMEN
BACKGROUND: Radiofrequency catheter ablation (RFCA) is an effective therapy for atrial fibrillation (AF). However, it the problem of AF recurrence remains. This study investigates whether a deep convolutional neural network (CNN) can accurately predict AF recurrence in patients with AF who underwent RFCA, and compares CNN with conventional statistical analysis.MethodsâandâResults:Three-hundred and ten patients with AF after RFCA treatment, including 94 patients with AF recurrence, were enrolled. Nine variables are identified as candidate predictors by univariate Cox proportional hazards regression (CPH). A CNNSurv model for AF recurrence prediction was proposed. The model's discrimination ability is validated by a 10-fold cross validation method and measured by C-index. After back elimination, 4 predictors are used for model development, they are N-terminal pro-BNP (NT-proBNP), paroxysmal AF (PAF), left atrial appendage volume (LAAV) and left atrial volume (LAV). The average testing C-index is 0.76 (0.72-0.79). The corresponding calibration plot appears to fit well to a diagonal, and the P value of the Hosmer-Lemeshow test also indicates the proposed model has good calibration ability. The proposed model has superior performance compared with the DeepSurv and multivariate CPH. The result of risk stratification indicates that patients with non-PAF, higher NT-proBNP, larger LAAV and LAV would have higher risks of AF recurrence. CONCLUSIONS: The proposed CNNSurv model has better performance than conventional statistical analysis, which may provide valuable guidance for clinical practice.
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Fibrilación Atrial , Ablación por Catéter , Aprendizaje Profundo , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/etiología , Fibrilación Atrial/cirugía , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , Humanos , Recurrencia , Resultado del TratamientoRESUMEN
The electrocardiogram (ECG) is widely used for cardiovascular disease diagnosis and daily health monitoring. Before ECG analysis, ECG quality screening is an essential but time-consuming and experience-dependent work for technicians. An automatic ECG quality assessment method can reduce unnecessary time loss to help cardiologists perform diagnosis. This study aims to develop an automatic quality assessment system to search qualified ECGs for interpretation. The proposed system consists of data augmentation and quality assessment parts. For data augmentation, we train a conditional generative adversarial networks model to get an ECG segment generator, and thus to increase the number of training data. Then, we pre-train a deep quality assessment model based on a training dataset composed of real and generated ECG. Finally, we fine-tune the proposed model using real ECG and validate it on two different datasets composed of real ECG. The proposed system has a generalized performance on the two validation datasets. The model's accuracy is 97.1% and 96.4%, respectively for the two datasets. The proposed method outperforms a shallow neural network model, and also a deep neural network models without being pre-trained by generated ECG. The proposed system demonstrates improved performance in the ECG quality assessment, and it has the potential to be an initial ECG quality screening tool in clinical practice.
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BACKGROUND: Transvenous implantable cardioverter defibrillator (TV-ICD) systems are commonly implanted in the left anterior chest because of an easier implantation and better defibrillation threshold. This study aimed to evaluate the safety and feasibility of left axillary implantations of TV-ICD systems. METHODS: We performed left axillary TV-ICD implantations and compared that to the major complication rate and operation time of the conventional TV-ICD implantation site (left anterior chest). The electrical parameter trends were also assessed in the left axilla group. RESULTS: Seventy-six consecutive patients were evaluated for the analysis. Thirty-one patients had their system implanted in the left axilla and the reasons for the implantations included 29 patients for cosmetic reasons and two for post-infection conditions. The operation time and major complication rate were similar between the two groups (left anterior chest vs. left axilla: 134±62.4 min vs. 114±33.5 min, p = .11, 1/45 patient, 2.2% [pocket hematoma] vs. 1/31 patient, 3.2% [lead dislodgement], p = .77). During the follow up period (4.9±2.3years), no lead interruptions were observed in either group. The electrical lead parameters at the time of the implantation and follow up were similar in the study group (R wave sensing 20.8±33.4 vs. 11.2±7.42 mv, p = .34; lead impedance 464±64.7 vs. 418±135ohm, p = .22; pacing threshold [at 0.4 ms] 1.0±0.76 vs. 1.21±0.93V, p = .49). CONCLUSION: TV-ICD implantations in the left axilla were performed safely without increasing the operation time as compared to the conventional ICD implantation site. ICD implantations in the left axilla are an alternative in those not suitable for implanting TV-ICDs in the conventional implantation site.
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Axila/cirugía , Desfibriladores Implantables , Seguridad del Paciente , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios RetrospectivosRESUMEN
OBJECTIVES: This study investigates the effect of stellate ganglion (SG) phototherapy in healthy participants and assesses its efficacy in suppressing electrical storm (ES) refractory to antiarrhythmic drugs and catheter ablation. BACKGROUND: Modulation of the autonomic nervous system has been shown to be an effective adjunctive therapy for ES. METHODS: Ten-minute SG phototherapy was performed twice weekly for 4 weeks in 20 healthy volunteers. To evaluate the acute and chronic effects of SG phototherapy, heart rate variability and serum concentrations of adrenaline, noradrenaline, and dopamine were obtained before phototherapy, immediately after the first phototherapy session, after 8 sessions of phototherapy, and 3 months after the first phototherapy session. In addition, the efficacy of SG phototherapy was evaluated in 11 patients with ES refractory to medication, sedation, and catheter ablation. RESULTS: In healthy participants, serum adrenaline concentration significantly decreased after phototherapy, whereas low-frequency power/high-frequency power significantly decreased during phototherapy. Moreover, the effect on heart rate variability did not last beyond 3 months. In the clinical pilot study, 7 patients had a suppression of ES after SG phototherapy; however, without maintenance therapy, 2 patients had a recurrence of ventricular arrhythmias. Furthermore, it did not control ES in 4 patients. CONCLUSIONS: SG phototherapy reduced sympathetic activity and may be a safe and effective adjunctive therapy to control ES in some patients, but its long-term efficacy remains unknown. Chronic phototherapy might help reduce ES recurrence.
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Ganglio Estrellado , Taquicardia Ventricular , Arritmias Cardíacas , Humanos , Rayos Láser , Fototerapia , Proyectos PilotoRESUMEN
BACKGROUND: Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is associated with left atrial (LA) remodeling; however, its association with right atrial (RA) remodeling remains unclear. OBJECTIVE: This study aimed to identify whether RA structural remodeling could predict recurrence of AF after PVI. METHODS: This study prospectively analyzed 245 patients with AF who had undergone PVI. RA and LA volumes were determined by contrast-enhanced computed tomography. Atrial structural remodeling was defined as an atrial volume of ≥110 mL according to previous reports and receiver operating characteristic curve analysis. RESULTS: After excluding 32 patients, 213 patients were analyzed. During a follow-up period of 12 months, 41 patients (19%) demonstrated atrial arrhythmia recurrence after PVI. With the Cox proportional-hazards model, RA structural remodeling was the only predictor of arrhythmia recurrence (hazard ratio, 1.012; 95% confidence interval 1.003-1.021; P = .009). Kaplan-Meier analysis showed that arrhythmia recurrence was more frequent in the RA structural remodeling group compared with the group without RA remodeling (log-rank, P < .001), and the arrhythmia-free survival rates in these groups at 12 months were 68.0% and 91.4%, respectively. Additionally, there was a significant difference in recurrence-free survival after RA structural remodeling in each type of AF (log-rank, P < .001). CONCLUSIONS: RA structural remodeling is a useful predictor of clinical outcome after PVI regardless of the type of AF. Our results suggest that patients without RA structural remodeling may be good candidates for successful ablation with PVI.
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BACKGROUND: Atrial fibrillation (AF) induces functional mitral regurgitation (FMR) and tricuspid regurgitation (FTR) during atrial remodeling. FMR and FTR are associated with AF prognosis, but the effects for AF recurrence after ablation have not been determined conclusively. METHODS: Two hundred thirty nine patients who underwent AF ablation were enrolled. Forty five patients were excluded. In total, 194 patients were analyzed. FMR and FTR were assessed by echocardiography. The left atrial volume index (LAVI) was evaluated by contrast-enhanced computed tomography. RESULTS: Significant FMR and moderate FTR were observed in 15 (7.7%) and in 25 (12.9%) patients, respectively. The severity of tricuspid regurgitation (TR) significant correlated with age, NT-proBNP, and LAVI. During a 13.4 month follow-up period of, 39 patients (20.1%) demonstrated AF recurrence. In the Cox proportional-hazards model, E/e', FTR, and LAVI, were termed as predictor factors of AF recurrence (E/e'. hazard ratio [HR] = 1.117; P = 0.019, significant FTR. HR = 4.679; P = 0.041, LAVI. HR = 1.057; P = 0.003). Kaplan-Meier analysis showed that AF recurrence was more frequent in FTR compared with the nonsignificant FTR cases (log-rank, P = 0.001). Although survival analysis showed no difference with or without FMR, the presence of FMR and FTR was strongly associated with high-AF recurrence (log-rank, P = 0.004). CONCLUSIONS: AF recurrence was associated with E/e', LAVI, and extensive FTR. Specifically, the combination of FTR and FMR markedly worsens the AF prognosis.
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Fibrilación Atrial , Insuficiencia de la Válvula Mitral , Insuficiencia de la Válvula Tricúspide , Fibrilación Atrial/cirugía , Electrocardiografía , Atrios Cardíacos , Humanos , Insuficiencia de la Válvula Mitral/cirugía , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/cirugíaRESUMEN
Obstructive sleep apnea (OSA) is a common chronic sleep disorder that disrupts breathing during sleep and is associated with many other medical conditions, including hypertension, coronary heart disease, and depression. Clinically, the standard for diagnosing OSA involves nocturnal polysomnography (PSG). However, this requires expert human intervention and considerable time, which limits the availability of OSA diagnosis in public health sectors. Therefore, electrocardiogram (ECG)-based methods for OSA detection have been proposed to automate the polysomnography procedure and reduce its discomfort. So far, most of the proposed approaches rely on feature engineering, which calls for advanced expert knowledge and experience. This paper proposes a novel fused-image-based technique that detects OSA using only a single-lead ECG signal. In the proposed approach, a convolutional neural network extracts features automatically from images created with one-minute ECG segments. The proposed network comprises 37 layers, including four residual blocks, a dense layer, a dropout layer, and a soft-max layer. In this study, three time-frequency representations, namely the scalogram, the spectrogram, and the Wigner-Ville distribution, were used to investigate the effectiveness of the fused-image-based approach. We found that blending scalogram and spectrogram images further improved the system's discriminative characteristics. Seventy ECG recordings from the PhysioNet Apnea-ECG database were used to train and evaluate the proposed model using 10-fold cross validation. The results of this study demonstrated that the proposed classifier can perform OSA detection with an average accuracy, recall, and specificity of 92.4%, 92.3%, and 92.6%, respectively, for the fused spectral images.
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Electrocardiografía , Redes Neurales de la Computación , Automatización , Bases de Datos Factuales , Humanos , Procesamiento de Imagen Asistido por Computador , Sensibilidad y Especificidad , Apnea Obstructiva del Sueño/diagnósticoRESUMEN
There is increased interest in creating high-power short duration (HPSD) ablation lesions in the field of atrial fibrillation (AF) radiofrequency ablation (RFA). We evaluated the lesion characteristics and collateral damage using two separate RFA protocols setting (HPSD: 50 W and 7 s vs control: 25 W and 30 s) in vitro model. Sixteen freshly killed porcine hearts were obtained, and the atrium and ventricle slabs were harvested for ablation. The each slabs were placed in a tissue bath with circulating 0.9% NaCl at maintained temperature 37 °C. RFA was performed with 4 mm tip irrigated force sensing catheter. All lesions were ablated under recording the electrical parameters using with Ensite Navx system (St. Jude Medical, St. Paul, Minnesota). After RFA, lesion characteristics were assessed for each lesion. Thirty-five lesions were made for each ablation protocol (total 70 lesions for analysis). Ablation parameters were similar between two groups (HPSD vs control; impedance drop (Ω): 34.2 ± 13.1 vs 36.1 ± 8.65 P = 0.49, contact force (g): 13.9 ± 4.37 vs 14.6 ± 5.09, P = 0.51, lesion size index: 4.8 ± 0.52 vs 4.73 ± 0.59, P = 0.62). Although the lesion volume was similar, the HPSD ablation creates wider but more shallower lesions compared to control group (HPSD vs control; lesion volume: 29.6 ± 18.1 mm3 vs 35.5 ± 17.1 mm3 P = 0.16, lesion diameter: 4.98 ± 0.91 mm vs 4.45 ± 0.74 mm P = 0.0095, lesion depth: 2.2 ± 0.76 mm vs 2.8 ± 1.56 mm P = 0.046). Of these, 38 lesions were assessed for adjacent tissue damage and adjacent tissue damages were more frequent seen in control group (HPSD vs control; 1/19 (5.26%) vs 6/19 (31.5%), P = 0.036). Effective lesions were made with HPSD, thereby reducing RFA procedure time. Although the lesion volume was similar between two groups, collateral damage was less seen in HPSD group attributed by lesion characteristics.
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Fibrilación Atrial , Ablación por Catéter , Ablación por Radiofrecuencia , Animales , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Ventrículos Cardíacos , Porcinos , Factores de TiempoRESUMEN
AIM: Arterial stiffness results in elevated left ventricular filling pressure and can promote atrial remodeling due to chronic pressure overload. However, the impact of arterial stiffness on the process of atrial remodeling in association with atrial fibrillation (AF) has not been fully evaluated. METHODS: We enrolled 237 consecutive patients diagnosed with AF who had undergone ablation; data from 213 patients were analyzed. Cardio-ankle vascular index (CAVI) was used as a marker of arterial stiffness. The left atrial (LA) and right atrial (RA) volumes were determined by computed tomography imaging; atrial conduction and voltage amplitude were evaluated using a three-dimensional electromapping system used to guide the ablation procedure. RESULT: In univariate analysis, CAVI significantly correlated with atrial structural and electrical remodeling (LA volume index, r=0.297, P=0.001; RA volume index, r=0.252, P=0.004; LA conduction velocity, r=0.254, P= 0.003; LA mean voltage, r=-0.343, P=0.001, RA mean voltage; r=-0.245, P=0.015). Multivariate regression analysis revealed that CAVI and plasma levels of N-terminal B-type natriuretic peptide were independent determinants of LA and RA remodeling, respectively. On the other hand, age and LA conduction velocity were independent variables with respect to CAVI. Age-adjusted CAVI was highest in long-standing persistent AF when compared with measures of persistent or paroxysmal AF. CONCLUSION: CAVI was closely associated with biatrial remodeling in patients diagnosed with AF. These results suggest that arterial stiffness may play a significant role with respect to disease progression.