Atrial fibrillation (AF) is one of the most common arrhythmias, which does great harm to patients. Effective methods were urgently required to prevent the recurrence of AF. Four methods were used to analyze RR sequence in this paper, and differences between Pre-AF (preceding an episode of AF) and Normal period (far away from episodes of AF) were analyzed to find discriminative criterion. These methods are: power spectral analysis, approximate entropy (ApEn) and sample entropy (SpEn) analysis, recurrence analysis and time series symbolization. The RR sequence data used in this research were downloaded from the Paroxysmal Atrial Fibrillation Prediction Database. Supporting vector machine (SVM) classification was used to evaluate the methods by calculating sensitivity, specificity and accuracy rate. The results showed that the comprehensive utilization of recurrence analysis parameters reached the highest accuracy rate (95%); power spectrum analysis took second place (90%); while the results of entropy analyses and time sequence symbolization were not satisfactory, whose accuracy were both only 70%. In conclusion, the recurrence analysis and power spectrum could be adopted to evaluate the atrial chaotic state effectively, thus having certain reference value for prediction of AF recurrence.
ObjectiveTo evaluate the efficacy of hybrid ablation through compared with thoracoscopic epicardial ablation.MethodsIn this study, 108 patients with all long-standing persistent atrial fibrillation (LSPAF) received thoracoscopic epicardial ablation (TEA) after enrollment. There were 82 males and 26 females at age of 56.5±9.4 years. After blanking-period, patients off antiarrhythmic therapy with sinus rhythm were divided into a hybrid ablation (HA) group (50 patients) and a TEA group (58 patients). Only patients in the HA group received catheter ablation after randomization subsequently. In at least two-year observation period, cardiovascular risk factors were observed in all groups’ patients.ResultsThe mean follow-up duration was 17.3-41.8 (26.9±6.1) months and there was no significant difference between two groups [8.2-40.6 (27.5±5.7) months in the HA group and 17.3-41.8 (26.4±6.7) months in the TEA group]. The off antiarrhythmic agents (AADs) sinus rhythm rate was significantly higher in the HA group than that in the TEA group at the time of postoperative 6, 12, 24 and 36 months ［96.0%, 90.0%, 83.7%, 83.7% versus 79.3%, 75.9%, 67.3%, 63.1%, HR=0.415 (95%CI 0.206-0.923)].ConclusionWe can conclude that the efficacy of two-staged hybrid ablation for LSPAF is superior to thoracoscopic epicardial ablation alone. Patients can obtain benefit from a supplemental radiofrequency catheter ablation after blanking-period of surgical ablation, instead of those without a supplemental ablation.
This study aims to explore the intraventricular pressure difference (IVPD) within left ventricle in patients with paroxysmal atrial fibrillation (PAF) by using the relative pressure imaging (RPI) of vector flow mapping (VFM). Twenty patients with paroxysmal atrial fibrillation (PAF) and thirty control subjects were enrolled in the study. Systolic and diastolic IVPD derived from VFM within left ventricle and conventional echocardiographic parameters were analyzed. It was found that the B-A IVPD of left ventricle in PAF patients showed the same pattern as controls—single peak and single valley during systole and double peaks and double valleys during diastole. Basal IVPD was the main component of base to apex IVPD (B-A IVPD). The isovolumetric systolic IVPD was associated with early systolic IVPD, early systolic IVPD was associated with late systolic IVPD, and late systolic IVPD was associated with isovolumic diastolic IVPD (all P < 0.05). The B-A IVPD and basal IVPD during isovolumetric systole, early systole, late systole and isovolumetric diastole in PAF patients significantly decreased (all P < 0.05). The study shows that the B-A IVPD pattern of the PAF group is the same as controls, but systolic B-A IVPD and basal IVPD are significantly reduced in PAF patients. VFM-derived RPI can evaluate left ventricular IVPD in PAF patients, providing a visually quantitative method for evaluating left ventricular hemodynamic mechanics in the patients with PAF.
ObjectiveTo investigate the technique and efficacy of left atrial appendage (LAA) occlusion during off-pump coronary artery bypass grafting (OPCABG) in elderly patients with coronary artery disease (CAD) and atrial fibrillation (AF).MethodsFrom 2013 to 2018, 84 elderly patients with CAD and AF with reduced left ventricular ejection fraction (LVEF< 50%) underwent OPCABG in our department. There were 54 males and 30 females at age of 70-82 years. They were divided into a left atrial appendage (LAA) occlusion group (n=56) and a non-LAA occlusion group (n=28). Postoperative antithrombotic therapy: the LAA occlusion group was given warfarin + aspirin + clopidogrel “triple antithrombotic therapy” for 3 months after operation, then was changed to aspirin + clopidogrel “dual antiplatelet” for long-term antithrombotic; the non-LAA occlusion group was given warfarin + aspirin + clopidogrel “triple antithrombotic” for long-term antithrombotic after operation. The clinical effectiveness of the two groups was compared.ResultsAll patients underwent the surgery successfully. There were 56 patients in the LAA occlusion group, including 44 patients of LAA exclusion and 12 patients of LAA clip. The time of LAA occlusion was 3 to 8 minutes. There was no injury of graft vessels and anastomotic stoma. Early postoperative death occurred in 2 patients (2.4%). There was no statistical difference between the two groups in postoperative hospital stay (P=0.115). Postoperative LVEF of the two groups significantly improved compared with that before operation (P<0.05). There was no stroke or bleeding in important organs during hospitalization. During follow-up of 1 year, no cerebral infarction occurred in both groups, but the incidence of bleeding related complications in the LAA occlusion group was significantly lower than that in the non-LAA occlusion group (3.6% vs. 18.5%, P=0.036).ConclusionFor elderly patients with CAD and AF with reduced LVEF, LAA occlusion during OPCABG can effectively reduce the risk of stroke and bleeding related complications, and without increasing the risk of surgery.
Atrial fibrillation (AF) is a common arrhythmia disease. Detection of atrial fibrillation based on electrocardiogram (ECG) is of great significance for clinical diagnosis. Due to the non-linearity and complexity of ECG signals, the procedure to manually diagnose the ECG signals takes a lot of time and is prone to errors. In order to overcome the above problems, a feature extraction method based on RR interval is proposed in this paper. The discrete degree of RR interval is described with the robust coefficient of variation (RCV), the distribution shape of RR interval is described with the skewness parameter (SKP), and the complexity of RR interval is described with the Lempel-Ziv complexity (LZC). Finally, the feature vectors of RCV, SKP, and LZC are input into the support vector machine (SVM) classifier model to achieve automatic classification and detection of atrial fibrillation. To verify the validity and practicability of the proposed method, the MIT-BIH atrial fibrillation database was used to verify the data. The final classification results show that the sensitivity is 95.81%, the specificity is 96.48%, the accuracy is 96.09%, and the specificity of 95.16% is achieved in the MIT-BIH normal sinus rhythm database. The experimental results show that the proposed method is an effective classification method for atrial fibrillation.
Objective To report the preliminary results of intraoperative saline-irrigated radiofrequency modified maze procedure for chronic atrial fibrillation (AF) in mitral valve diseases. Methods From May 2003 to April 2004 forty-one patients underwent intraoperative saline-irrigated modified maze procedure. The patients included 13 male and 28 female. Their age ranged from 27-65 years (46±10 years). The duration of AF varied from 5 months to 15 years (4.5±3.6 years).The left atrial diameter varied from 37-93 mm (54±11mm). There were mitral stenosis 20, mitral regurgitation 1 and mitral stenosis with regurgitation 20 cases. Cardiopulmonary bypass (CPB) was established as usual. Ablation lines were made with Cardioblate (Medtronic, 25-30 W, 180-240ml/h). Having finished right-sided maze procedure, the aorta was cross-clamped and cold crystalloid or blood cardioplegia were used for myocardial protection. Left atrial incision was performed through the interatrial groove. The ablation lines were created to encircle the orifices of the left and right pulmonary veins respectively. The ablation lines were also performed from the left encircling line to the posterior mitral valvular annulus and to the orifice of left atrial appendage respectively. A ablation line was used to connect left and right pulmonary veins circumferential line. Concomitant procedures were performed (there were double valve replacement 10 cases, mitral valve replacement 31 cases, tricuspid annuloplasty 6 cases, removing the left atrial thrombi 6 cases). Results CPB time varied from 71-160 min (105±24 min) and cross-clamping time varied from 32-106 min (62±20 min). The ablation time varied from 4-22 min (11±4 min). One patient died during hospitalization and the death was caused by acute mechanic valve obstruction. During follow-up at discharge and 3 months 35% patients (14/40) were free of AF and the others were not. But at 6 months 67% patients (10/15) were free of AF. Conclusion The intraoperative saline-irrigated radiofrequency modified maze procedure is comparatively simpler and its efficacy is satisfactory.
Atrial fibrillation is a common and refractory atrial arrhythmia. Changes of atrial mechanical circumstances are closely related to the occurrence and maintenance of atrial fibrillation. Mechanical factors can increase the automaticity, slow conduction velocity and shorten the effective refractory period of the atrium by causing electrical and structural remodeling, and eventually increase the inducibility of atrial fibrillation. The intracellular calcium level, function and structure of cytoskeleton, local renin-angiotensin system, integrin and mitogen-activated protein kinases (MAPKs) pathway might take part in the process. Here we analyze and review the underlining mechano-electric feedback process of atrial fibrillation and its related research in order to provide a theoretical basis for further research and elucidating of the mechanical mechanism of atrial fibrillation.
Objective To summarize safety and effectiveness of cryomaze ablation procedure concomitant with valve surgery. Methods We retrospectively investigated the clinical data of 62 patients (24 males and 38 females) with mean age of 49.4±14.2 years who underwent cryomaze ablation procedure concomitant with valve surgery in our hospital from August 2013 through July 2015. The heart rhythm of the patients after surgery was supervised by 12-leads electrical cardiogram respectively. Results The rate of sinus rhythm restored right after surgery was 98.4%. The rate of sinus rhythm restored at the time of discharge was 93.4%. The rate of sinus rhythm restored 3 months, 6 months, 12 months, 18 months after surgery was 90.2%, 87.3%, 85.0%, 83.3% respectively. The one-year post-operation rate of sinus rhythm restored for the group of right minimal invasive thoracoscopic assisted mitral valve surgery was 90.5%. Longer duration for atrial fibrillation (>7 years) was a risk factor for the reoccurrence of atrial fibrillation 1 year after surgery (P<0.05). Conclusion Cryomaze ablation procedure concomitant with valve surgery is quite effective in treatment of rheumatic valve disease and atrial fibrillation. This approach is associated with fewer complications, comparable atrial fibrillation reoccurrence for short-term follow-up.
Atrial fibrillation (AF) is one of the most common arrhythmias. Today, there are a large number of AF patients worldwide, and incidence increases with the increase of age. However, the current diagnosis rate of AF via auxiliary examination is relatively low. In view of the widespread application of artificial intelligence (AI) in the medical field, the diagnosis of AF using AI has also become a research hotspot. This article briefly introduces the relevant aspects of AI and reviews the application of AI in AF prediction.
ObjectiveTo analyze the clinical characteristics of stiff left atrial syndrome (SLAS) after Mei mini maze procedure for atrial fibrillation (AF), and to explore its risk factors and treatments. Methods We retrospectively analyzed the clinical data of the patients who underwent Mei mini maze procedure in Xinhua Hospital between 2010 and 2020. According to whether SLAS occurred in the early postoperative period, patients were divided into a SLAS group and a non-SLAS group. The basic data, perioperative echocardiogram and laboratory test indexes of the two groups were compared. Results A total of 1 056 patients were collected. There were 672 (63.6%) males with an average age of 63.6±9.3 years, including 489 patients with persistent AF and 567 patients with paroxysmal AF. Fourteen (14/1 056, 1.3%) patients developed SLAS, with an average occurrence time of 2.1±1.1 days after the surgery. The average follow-up time of the whole group was 21.4±7.8 months. Two patients in the SLAS group developed SLAS again after discharge, and the occurrence time was 3 weeks and 4 weeks after the operation, respectively; while no SLAS occurred after discharge in the non-SLAS group. Diabetes and small preoperative left atrial diameter were risk factors for SLAS after surgery. Patients with SLAS had a good prognosis after adequate diuretic therapy. Conclusion The incidence of SLAS after Mei mini maze procedure for AF is low, and it mostly occurs in the early postoperative period. After adequate diuretic treatment, the prognosis is good.