针对并联型有源电力滤波器(active power filter,APF)谐波检测环节的延时和谐波电流跟踪环节的鲁棒性差、跟踪精度不高的问题,建立了系统解耦后的数学模型,提出了基于递归最小二乘(recursive least squares,RLS)算法的并联型APF全局积...针对并联型有源电力滤波器(active power filter,APF)谐波检测环节的延时和谐波电流跟踪环节的鲁棒性差、跟踪精度不高的问题,建立了系统解耦后的数学模型,提出了基于递归最小二乘(recursive least squares,RLS)算法的并联型APF全局积分滑模变结构控制策略。谐波检测环节采用改进的瞬时无功功率理论的id-iq法,用RLS自适应滤波器替换传统的Butterworth低通滤波器,解决了传统的Butterworth低通滤波器因延时而导致的一个基波周期(20 ms)内检测盲区问题。谐波电流跟踪环节采用全局积分滑模变结构控制方法,引入了全局积分滑模面,运用Lyapunov稳定性理论导出的控制律兼顾了全局滑模的快速性和积分滑模的准确性。在解决了谐波检测环节延时的情况下,将全局积分滑模控制策略与传统的PI控制和滞环控制对比,仿真实验结果表明:全局积分滑模控制对指令电流具有更高的跟踪精度,且具有更低的电网侧电流总谐波畸变率(total harmonic distortion,THD)。展开更多
BACKGROUND Cardiogenic embolism caused by patent foramen ovale(PFO)is a common etiology of cryptogenic stroke(CS),particularly in young and middle-aged patients.Studies about right-to-left shunt(RLS)detection using co...BACKGROUND Cardiogenic embolism caused by patent foramen ovale(PFO)is a common etiology of cryptogenic stroke(CS),particularly in young and middle-aged patients.Studies about right-to-left shunt(RLS)detection using contrast-enhanced transcranial Doppler(c-TCD)are numerous.According to the time phase and number of microbubbles detected on c-TCD,RLS can be classified and graded.We hypothesized that the characteristics of an infarction lesion on diffusion-weighted imaging differs when combining the type and grade of RLS on c-TCD in patients with PFO-related CS.AIM To explore the characteristics of infarction lesions on diffusion-weighted imaging when combining the RLS type and grade determined by c-TCD.METHODS We retrospectively evaluated CS patients from August 2015 to December 2019 at a tertiary hospital.In total,111 PFO-related CS patients were divided according to whether RLS was permanent(microbubbles detected both at resting state and after the Valsalva maneuver)or latent(microbubbles detected only after the Valsalva maneuver)on c-TCD.Each group was subdivided into small,mild and large RLS according to the grade of shunt on c-TCD.A normal control group was composed of 33 patients who suffered from simple dizziness.Intragroup and intergroup differences were analyzed in terms of clinical,laboratory and diffusion-weighted imaging lesion characteristics.The correlation between RLS grade evaluated by c-TCD and size of PFO determined by transesophageal echocardiography were also analyzed.RESULTS In 111 patients with PFO-related CS,68 had permanent RLS and 43 had latent RLS.Clinical characteristics and laboratory tests were not significantly different among the permanent RLS,latent RLS and normal control groups.The proportion of patients with multiple territory lesions in the permanent RLS group(50%)was larger than that in the latent RLS group(27.91%;P=0.021).Posterior circulation was more likely to be affected in the latent RLS group than in the permanent RLS group(30.23%vs 8.82%,P=0.004).Permanent-large and latent-large RLS were both more likely to be related to multiple(P_(trend)=0.017 and 0.009,respectively),small(P_(trend)=0.035 and 0.006,respectively)and cortical(P_(trend)=0.031 and 0.033,respectively)lesions.The grade of RLS evaluated by c-TCD was correlated to the size of PFO determined by transesophageal echocardiography(r=0.758,P<0.001).CONCLUSION Distribution of the infarct suggested the possible type of RLS.Multiple,small and cortical infarcts suggest large RLS induced by a large PFO.展开更多
BACKGROUND Patients with tetralogy of Fallot(TOF)often have arrhythmias,commonly being atrial fibrillation(AF).Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative h...BACKGROUND Patients with tetralogy of Fallot(TOF)often have arrhythmias,commonly being atrial fibrillation(AF).Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative hypoxemia,but the risk of complications may increase in patients with conditions such as TOF.CASE SUMMARY We report a young male patient with a history of TOF repair who developed severe hypoxemia after radiofrequency ablation for AF and was ultimately confirmed to have a new right-to-left shunt.The patient subsequently underwent atrial septal occlusion and eventually recovered.CONCLUSION Radiofrequency ablation may cause iatrogenic atrial septal injury;thus possible complications should be predicted in order to ensure successful treatment and patient safety.展开更多
Patent foramen ovale (PFO) closure for systemic hypoxemia is controversial. The first systematic, albeit retrospective, study was recently presented which showed good procedural and clinical success for PFO closure fo...Patent foramen ovale (PFO) closure for systemic hypoxemia is controversial. The first systematic, albeit retrospective, study was recently presented which showed good procedural and clinical success for PFO closure for this indication. We present a case of acute right to left intra-cardiac shunt across PFO where the shunting is not persistent. Hence making a decision on PFO closure based on the aforementioned promising trial may not have been the right decision for the patient. This case highlights that the decision on PFO closure for such indication needs to be individualized. We also review the sparse literature on PFO closure for this indication and discuss how the decision making for such indication needs to be individualized.展开更多
AIM To test the potential association between atrial septal aneurysm(ASA) and migraine in patent foramen ovale(PFO) closure patients through an observational, singlecenter, case-controlled study.METHODS We studied a t...AIM To test the potential association between atrial septal aneurysm(ASA) and migraine in patent foramen ovale(PFO) closure patients through an observational, singlecenter, case-controlled study.METHODS We studied a total of 450 migraineurs who had rightto-left shunts and underwent PFO closure in a retrospective single-center non-randomized registry from February 2012 to October 2016 on the condition that they were aged 18-45 years old. Migraine was diagnosed according to the International Classification of Headache Disorders, 3^(rd) edition and evaluated using the Headache Impact Test-6(HIT-6). All patients underwent preoperative transesophageal echocardiography, contrast transthoracic echocardiography, and computed tomography or magnetic resonance imaging examinations, with subsequent fluoroscopy-guided PFO closure. Based on whether they have ASA or not, the patients were divided into two groups: A(PFO with ASA, n = 80) and B(PFO without ASA, n = 370). Baseline characteristics and procedural and follow-up data were reviewed. RESULTS Compared to group B, group A had an increased frequency of ischemic lesions(11.3% vs 6.2%, P = 0.038) and migraine with aura(32.5% vs 21.1%, P = 0.040). The PFO size was significantly larger in group A(P = 0.007). There was no significant difference in HIT-6 scores between the two groups before and at the oneyear follow-up after the PFO closure [61(9) vs 63(9), P = 0.227; 36(13) vs 36(10), P = 0.706].CONCLUSION Despite its small sample size, our study suggests that the prevalence of ASA in PFO with migraine patients is associated with ischemic stroke, larger PFO size, and migraine with aura.展开更多
AIM: To investigate long-term efficacy of two different devices more than five years after percutaneous atrial septal defect(ASD) closure in adults.METHODS: All patients who underwent percutaneous closure of an ASD in...AIM: To investigate long-term efficacy of two different devices more than five years after percutaneous atrial septal defect(ASD) closure in adults.METHODS: All patients who underwent percutaneous closure of an ASD in the St. Antonius Hospital, Nieuwegein, The Netherlands, between February 1998 and December 2006 were included. Percutaneous closure took place under general anaesthesia and transesophageal echocardiographic moni toring. Transthoracic echocardiography(TTE) was performed 24 h post-procedure to visualize the device position and to look for residual shunting using color Doppler. All complications were registered. All patients were invited for an outpatient visit and contrast TTE more than 5-years after closure. Efficacy was based on the presence of a residual right-to-left shunt(RLS), graded as minimal, moderate or severe. The presence of a residual left-to-right shunt(LRS) was diagnosed using color Doppler, and was not graded. Descriptive statistics were used for patients' characteristics. Univariate analysis was used to identify predictors for residual shunting.RESULTS: In total, 104 patients(mean age 45.5 ± 17.1 years) underwent percutaneous ASD closure using an Amplatzer device(ASO) in 76 patients and a Cardioseal/Starflex device(CS/SF) in 28 patients. The mean follow-up was 6.4 ± 3.4 years. Device migration occurred in 4 patients of whom two cases occurred during the index hospitalization(1 ASO, 1 CS/SF). The other 2 cases of device migration occurred during the first 6 mo of follow-up(2 CS/SF). The recurrent thrombo-embolic event rate was similar in both groups: 0.4% per follow-up year. More than 12 mo post-ASD closure and latest follow-up, new-onset supraventricular tachyarrhythmia's occurred in 3.9% and 0% for the ASO and CS/SF group, respectively. The RLS rate at latest follow-up was 17.4%(minimal 10.9%, moderate 2.2%, severe 4.3%) and 45.5%(minimal 27.3%, moderate 18.2%, severe 0%) for the ASO- and CS/SF groups, respectively. There was no residual LRS in both groups.CONCLUSION: Percutaneous ASD closure has good long-term safety and efficacy profiles. The residual RLS rate seems to be high more than 5 years after closure, especially in the CS/SF. Residual LRS was not observed.展开更多
Catheter-based closure of patent foramen ovale(PFO)is more effective than medical therapy in the prevention of recurrent stroke[1].It is likely that a proportion of patients evaluated for potential transcatheter PFO c...Catheter-based closure of patent foramen ovale(PFO)is more effective than medical therapy in the prevention of recurrent stroke[1].It is likely that a proportion of patients evaluated for potential transcatheter PFO closure has actually different anatomical variants particularly common in the right atrium such as eustachian valve,Chiari network,Thebesian valve and Crista Terminalis.Notably,the eustachian valve may represent an increased risk factor for left circulation thromboembolism beyond that associated with PFO size and shunting.Such patients may benefit the most from percutaneous closure procedure.展开更多
文摘针对并联型有源电力滤波器(active power filter,APF)谐波检测环节的延时和谐波电流跟踪环节的鲁棒性差、跟踪精度不高的问题,建立了系统解耦后的数学模型,提出了基于递归最小二乘(recursive least squares,RLS)算法的并联型APF全局积分滑模变结构控制策略。谐波检测环节采用改进的瞬时无功功率理论的id-iq法,用RLS自适应滤波器替换传统的Butterworth低通滤波器,解决了传统的Butterworth低通滤波器因延时而导致的一个基波周期(20 ms)内检测盲区问题。谐波电流跟踪环节采用全局积分滑模变结构控制方法,引入了全局积分滑模面,运用Lyapunov稳定性理论导出的控制律兼顾了全局滑模的快速性和积分滑模的准确性。在解决了谐波检测环节延时的情况下,将全局积分滑模控制策略与传统的PI控制和滞环控制对比,仿真实验结果表明:全局积分滑模控制对指令电流具有更高的跟踪精度,且具有更低的电网侧电流总谐波畸变率(total harmonic distortion,THD)。
基金People’s Livelihood Science and Technology Project(Research on Application of Key Technologies)of Suzhou(No.SS202061)Technical Cooperation Project of Soochow University(No.H211064).
文摘BACKGROUND Cardiogenic embolism caused by patent foramen ovale(PFO)is a common etiology of cryptogenic stroke(CS),particularly in young and middle-aged patients.Studies about right-to-left shunt(RLS)detection using contrast-enhanced transcranial Doppler(c-TCD)are numerous.According to the time phase and number of microbubbles detected on c-TCD,RLS can be classified and graded.We hypothesized that the characteristics of an infarction lesion on diffusion-weighted imaging differs when combining the type and grade of RLS on c-TCD in patients with PFO-related CS.AIM To explore the characteristics of infarction lesions on diffusion-weighted imaging when combining the RLS type and grade determined by c-TCD.METHODS We retrospectively evaluated CS patients from August 2015 to December 2019 at a tertiary hospital.In total,111 PFO-related CS patients were divided according to whether RLS was permanent(microbubbles detected both at resting state and after the Valsalva maneuver)or latent(microbubbles detected only after the Valsalva maneuver)on c-TCD.Each group was subdivided into small,mild and large RLS according to the grade of shunt on c-TCD.A normal control group was composed of 33 patients who suffered from simple dizziness.Intragroup and intergroup differences were analyzed in terms of clinical,laboratory and diffusion-weighted imaging lesion characteristics.The correlation between RLS grade evaluated by c-TCD and size of PFO determined by transesophageal echocardiography were also analyzed.RESULTS In 111 patients with PFO-related CS,68 had permanent RLS and 43 had latent RLS.Clinical characteristics and laboratory tests were not significantly different among the permanent RLS,latent RLS and normal control groups.The proportion of patients with multiple territory lesions in the permanent RLS group(50%)was larger than that in the latent RLS group(27.91%;P=0.021).Posterior circulation was more likely to be affected in the latent RLS group than in the permanent RLS group(30.23%vs 8.82%,P=0.004).Permanent-large and latent-large RLS were both more likely to be related to multiple(P_(trend)=0.017 and 0.009,respectively),small(P_(trend)=0.035 and 0.006,respectively)and cortical(P_(trend)=0.031 and 0.033,respectively)lesions.The grade of RLS evaluated by c-TCD was correlated to the size of PFO determined by transesophageal echocardiography(r=0.758,P<0.001).CONCLUSION Distribution of the infarct suggested the possible type of RLS.Multiple,small and cortical infarcts suggest large RLS induced by a large PFO.
文摘BACKGROUND Patients with tetralogy of Fallot(TOF)often have arrhythmias,commonly being atrial fibrillation(AF).Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative hypoxemia,but the risk of complications may increase in patients with conditions such as TOF.CASE SUMMARY We report a young male patient with a history of TOF repair who developed severe hypoxemia after radiofrequency ablation for AF and was ultimately confirmed to have a new right-to-left shunt.The patient subsequently underwent atrial septal occlusion and eventually recovered.CONCLUSION Radiofrequency ablation may cause iatrogenic atrial septal injury;thus possible complications should be predicted in order to ensure successful treatment and patient safety.
文摘Patent foramen ovale (PFO) closure for systemic hypoxemia is controversial. The first systematic, albeit retrospective, study was recently presented which showed good procedural and clinical success for PFO closure for this indication. We present a case of acute right to left intra-cardiac shunt across PFO where the shunting is not persistent. Hence making a decision on PFO closure based on the aforementioned promising trial may not have been the right decision for the patient. This case highlights that the decision on PFO closure for such indication needs to be individualized. We also review the sparse literature on PFO closure for this indication and discuss how the decision making for such indication needs to be individualized.
文摘AIM To test the potential association between atrial septal aneurysm(ASA) and migraine in patent foramen ovale(PFO) closure patients through an observational, singlecenter, case-controlled study.METHODS We studied a total of 450 migraineurs who had rightto-left shunts and underwent PFO closure in a retrospective single-center non-randomized registry from February 2012 to October 2016 on the condition that they were aged 18-45 years old. Migraine was diagnosed according to the International Classification of Headache Disorders, 3^(rd) edition and evaluated using the Headache Impact Test-6(HIT-6). All patients underwent preoperative transesophageal echocardiography, contrast transthoracic echocardiography, and computed tomography or magnetic resonance imaging examinations, with subsequent fluoroscopy-guided PFO closure. Based on whether they have ASA or not, the patients were divided into two groups: A(PFO with ASA, n = 80) and B(PFO without ASA, n = 370). Baseline characteristics and procedural and follow-up data were reviewed. RESULTS Compared to group B, group A had an increased frequency of ischemic lesions(11.3% vs 6.2%, P = 0.038) and migraine with aura(32.5% vs 21.1%, P = 0.040). The PFO size was significantly larger in group A(P = 0.007). There was no significant difference in HIT-6 scores between the two groups before and at the oneyear follow-up after the PFO closure [61(9) vs 63(9), P = 0.227; 36(13) vs 36(10), P = 0.706].CONCLUSION Despite its small sample size, our study suggests that the prevalence of ASA in PFO with migraine patients is associated with ischemic stroke, larger PFO size, and migraine with aura.
文摘AIM: To investigate long-term efficacy of two different devices more than five years after percutaneous atrial septal defect(ASD) closure in adults.METHODS: All patients who underwent percutaneous closure of an ASD in the St. Antonius Hospital, Nieuwegein, The Netherlands, between February 1998 and December 2006 were included. Percutaneous closure took place under general anaesthesia and transesophageal echocardiographic moni toring. Transthoracic echocardiography(TTE) was performed 24 h post-procedure to visualize the device position and to look for residual shunting using color Doppler. All complications were registered. All patients were invited for an outpatient visit and contrast TTE more than 5-years after closure. Efficacy was based on the presence of a residual right-to-left shunt(RLS), graded as minimal, moderate or severe. The presence of a residual left-to-right shunt(LRS) was diagnosed using color Doppler, and was not graded. Descriptive statistics were used for patients' characteristics. Univariate analysis was used to identify predictors for residual shunting.RESULTS: In total, 104 patients(mean age 45.5 ± 17.1 years) underwent percutaneous ASD closure using an Amplatzer device(ASO) in 76 patients and a Cardioseal/Starflex device(CS/SF) in 28 patients. The mean follow-up was 6.4 ± 3.4 years. Device migration occurred in 4 patients of whom two cases occurred during the index hospitalization(1 ASO, 1 CS/SF). The other 2 cases of device migration occurred during the first 6 mo of follow-up(2 CS/SF). The recurrent thrombo-embolic event rate was similar in both groups: 0.4% per follow-up year. More than 12 mo post-ASD closure and latest follow-up, new-onset supraventricular tachyarrhythmia's occurred in 3.9% and 0% for the ASO and CS/SF group, respectively. The RLS rate at latest follow-up was 17.4%(minimal 10.9%, moderate 2.2%, severe 4.3%) and 45.5%(minimal 27.3%, moderate 18.2%, severe 0%) for the ASO- and CS/SF groups, respectively. There was no residual LRS in both groups.CONCLUSION: Percutaneous ASD closure has good long-term safety and efficacy profiles. The residual RLS rate seems to be high more than 5 years after closure, especially in the CS/SF. Residual LRS was not observed.
文摘Catheter-based closure of patent foramen ovale(PFO)is more effective than medical therapy in the prevention of recurrent stroke[1].It is likely that a proportion of patients evaluated for potential transcatheter PFO closure has actually different anatomical variants particularly common in the right atrium such as eustachian valve,Chiari network,Thebesian valve and Crista Terminalis.Notably,the eustachian valve may represent an increased risk factor for left circulation thromboembolism beyond that associated with PFO size and shunting.Such patients may benefit the most from percutaneous closure procedure.
