胎儿心电信号的无创提取：基于时间卷积编解码网络

目的 实现从孕妇腹壁混合心电信号中提取微弱的胎儿心电信号,为准确估计胎儿心率、分析胎儿心电波形等提供基础。方法 利用深度卷积网络（deep CNN）优越的非线性映射能力,本文提出了一种基于时间卷积编解码网络的非线性自适应噪声消除（nonlinear ANC）提取框架,以实现胎儿心电信号的有效提取。首先构建适用于处理胎儿心电信号的深度时间卷积网络（TCED-Net）模型作为非线性映射工具;然后以孕妇胸部心电信号为参考,利用该模型估计孕妇腹壁混合心电信号中的母体心电成分;最后从腹壁混合信号中减去所估计的母体心电成分,以得到完整的胎儿心电信号。实验利用合成心电数据（FECGSYNDB）和临床心电数据（NIFECGDB、PCDB）对方法性能进行测试与对比。结果 本文方法在FECGSYNDB上的胎儿R峰检测精度（[F1]值）、均方误差（MSE）和质量信噪比（qSNR）分别达到98.89 %,0.20和7.84;在NIFECGDB上的[F1]值达到99.1%;在 PCDB 上的[F1]值达到 98.61%。在不同数据集中较之 EKF（[F1=]93.84%）、ES-RNN([F1] =97.20% )和 AECG-DecompNet（[F1]=95.43%）等现有性能最佳的算法,本文方法的R峰检测精度指标分别高出5.05%、1.9%和3.18%,均优于现有最佳方法。结论 与现有算法相比,本文方法可以提取出更为清晰的胎儿心电信号,对孕期进行有效的胎儿健康监护具有一定的应用价值。     

Localization of accessory pathways in the Wolff-Parkinson-White pattern--physician versus computer interpretation of the same algorithm

BACKGROUND: There are several published algorithms for the prediction of accessory pathway (AP) location in the Wolff-Parkinson-White syndrome from the 12-lead electrocardiogram (ECG). Most depend on stepwise criteria, and minor disagreements between observers over QRS transition point or delta wave axis may lead to different classification of pathway location. We compared the utility of a computerized program in identifying pathway location from the ECG using the algorithm published by Fitzpatrick and coworkers(3) against physician assessment with the same algorithm. METHODS: Thirty-one 12-lead ECGs with an overt preexcitation pattern were examined by three physicians and AP localized to one of eight anatomical sites using the Fitzpatrick algorithm, with disagreements resolved by consensus. Similarly, pathway location was determined by the Glasgow ECG program with the Fitzpatrick algorithm incorporated into its logic. RESULTS: The agreement between each physician and their consensus was 28/31, 29/31, and 29/31. Similarly, assessment by the Glasgow program produced agreement with the physician consensus in 29/31 cases. Of the 24 patients who underwent radiofrequency ablation, the program localized the pathway to the true or adjacent annular region in 20, compared to 20/24 by physician assessment of the algorithm, producing a similar predictive accuracy to published data. CONCLUSION: This study has shown that incorporation of the Fitzpatrick algorithm for AP location into a widely used computer program results in the same level of performance as that of experienced physicians and may be useful in clinical practice as an aid to referral for electrophysiological study and ablation.     

Artificial Intelligence for Automatic Measurement of Left Ventricular Strain in Echocardiography

ObjectivesThis study sought to examine if fully automated measurements of global longitudinal strain (GLS) using a novel motion estimation technology based on deep learning and artificial intelligence (AI) are feasible and comparable with a conventional speckle-tracking application.BackgroundGLS is an important parameter when evaluating left ventricular function. However, analyses of GLS are time consuming and demand expertise, and thus are underused in clinical practice.MethodsIn this study, 200 patients with a wide range of left ventricle (LV) function were included. Three standard apical cine-loops were analyzed using the AI pipeline. The AI method measured GLS and was compared with a commercially available semiautomatic speckle-tracking software (EchoPAC v202, GE Healthcare.ResultsThe AI method succeeded to both correctly classify all 3 standard apical views and perform timing of cardiac events in 89% of patients. Furthermore, the method successfully performed automatic segmentation, motion estimates, and measurements of GLS in all examinations, across different cardiac pathologies and throughout the spectrum of LV function. GLS was −12.0 ± 4.1% for the AI method and −13.5 ± 5.3% for the reference method. Bias was −1.4 ± 0.3% (95% limits of agreement: 2.3 to −5.1), which is comparable with intervendor studies. The AI method eliminated measurement variability and a complete GLS analysis was processed within 15 s.ConclusionsThrough the range of LV function this novel AI method succeeds, without any operator input, to automatically identify the 3 standard apical views, perform timing of cardiac events, trace the myocardium, perform motion estimation, and measure GLS. Fully automated measurements based on AI could facilitate the clinical implementation of GLS.     

Registro Español de Marcapasos. XVIII Informe Oficial de la Sección de Estimulación Cardiaca de la Sociedad Española de Cardiología (2020)

Introduction and objectivesThis report describes the cardiac pacing activity performed in Spain in 2020, including the number and type of implanted devices, demographic and clinical factors, and data on remote monitoring.MethodsInformation consisted of the European Pacemaker Patient Card, data submitted to the cardiodispositivos.es online platform, the databases of participating centers, and supplier-reported data.ResultsA total of 14 662 procedures were registered from 102 hospitals, representing 39.2% of the estimated activity. The implantation rates of conventional and low-energy resynchronization pacemakers were 759 and 31 units per million population, respectively. In all, 520 leadless pacemakers were implanted, 70 with atrioventricular synchrony. The mean age at implantation was high (78.8 years), and the most frequent electrocardiographic change was atrioventricular block. There was a predominance of dual-chamber pacing mode but VVI/R single-chamber pacing was used in 19% of patients in sinus rhythm, depending on age and sex. Remote monitoring capability was present in 18.5% of implanted conventional pacemakers and 45.6% of low-energy resynchronization pacemakers, although registration in this system increased by 53% in 2020.ConclusionsIn 2020, in the context of the SARS-CoV-2 pandemic, the number of implanted conventional pacemakers decreased by 8% and cardiac resynchronization therapy by 4.6%. The number of leadless pacemakers increased by 16.5%. Sequential pacing was predominant, influenced by age and sex. Home monitoring played a fundamental role as a mode of follow-up in this SARS-CoV-2 pandemic year.Full English text available from:www.revespcardiol.org/en     

Emergency Medicine Residency Training in Electrocardiogram Interpretation

OBJECTIVES: A national survey of emergency medicine (EM) residency program directors (PDs) was conducted to review training and evaluation of residents in electrocardiogram (ECG) interpretation and to assess the attitudes of PDs toward establishing national criteria for ECG competency. METHODS: An eight-question multiple-part survey was mailed to all 122 EM PDs. The presence of a formal ECG curriculum, teaching formats, and methods to assess competency were queried. The PDs' opinions on developing a national ECG curriculum, standardized assessment tool, and competency requirement for graduation were solicited on a five-point Likert scale. RESULTS: Surveys were received from 87 (71.3%) of the 122 EM residency programs. Of the responding programs, 56 (64.4%) had a formal ECG curriculum. Only 18 (20.7%) programs stated that they test for ECG competency, and even fewer, ten (11.5%) programs, require that residents prove competency to graduate. Although 32 (48.3%) PDs endorsed the idea of a national ECG curriculum, 51 (58.6%) opposed the implementation of a national ECG examination for EM. Similarly, 50 (57.5%) PDs opposed a national ECG competency requirement for graduation. CONCLUSIONS: While a majority of EM residency programs surveyed have a formal curriculum for ECG interpretation, less than a fourth formally test their residents or require proof of competency. The majority of residency PDs oppose the development of a national ECG examination or competency requirement for graduation. Implementation of the Accreditation Council for Graduate Medical Education directive for the demonstration of clinical competencies will be challenging given the current position of PDs.     

A comparative study of the postoperative allogeneic blood-sparing effects of tranexamic acid and of desmopressin after total knee replacement

BACKGROUND: Tissue hypoxia and reperfusion induce abnormal hemostatic function. Therefore, bleeding after total knee replacement (TKR) may be a result of a tourniquet-induced imbalance of the procoagulant and fibrinolytic systems. Because laboratory confirmation of tourniquet-induced abnormal hemostasis is difficult to obtain, indirect evidence must be sought. STUDY DESIGN AND METHODS: A prospective, single-blind study of 40 patients undergoing TKR was performed. In the tranexamic acid (TA) group, in the 30 minutes before the limb tourniquet was deflated, an IV bolus dose of TA (15 mg/kg) was administered. Thereafter, a constant IV infusion of 10 mg per kg per hour was administered until 12 hours after tourniquet deflation. In the desmopressin group, desmopressin (0.3 mg/kg) and saline were administered by a similar protocol. No blood was administered intraoperatively. A postoperative Hct <27 percent constituted the postoperative transfusion trigger. Patients were examined daily for signs of lower-limb deep vein thrombosis, and they underwent lower-limb Doppler ultrasound on postoperative Day 5. Three months after surgery, the incidence of delayed thromboembolic events was assessed. RESULTS: During the first 12 postoperative hours, blood accumulation in the surgical drain was significantly (p<0.05) lower in the TA group (162 mL +/- 129) than in the desmopressin group (342 mL +/- 169). From the sixth postoperative hour until 3 days postoperatively, Hct levels were significantly lower in the desmopressin group than in the TA group. Significantly more allogeneic blood was transfused in the desmopressin group (11 patients received 16 units) than in the TA group (3 patients each received 1 unit) (p<0.02). There were no clinical signs of deep vein thrombosis or abnormal Doppler ultrasound studies. Three months postoperatively, there were no thromboembolic events among the 37 patients interviewed. CONCLUSION: TA induces better blood sparing than desmopressin. Therefore, a tourniquet-induced increase in fibrinolysis is the likely cause of delayed bleeding after TKR surgery. However, before routine administration, the effect of TA on the incidence of thromboembolic events requires further investigation.     

犬急性右心室心肌梗塞时的右胸心电图变化

目的：观察犬心大面积右室、左室梗塞时的Ｗｉｌｓｏｎ导联和头胸（ＨＣ）导联右胸心电图变化特征。方法：结扎犬心４支冠状动脉（冠脉），造成大面积右室、左室梗塞并发右心衰竭和心原性休克模型，观察６只犬在正常时、依序结扎每支冠脉后以及第６小时共６个时间段ＷｉｌｓｏｎＶ３Ｒ～Ｖ６Ｒ和相同部位头胸ＨＶ３Ｒ～ＨＶ６Ｒ图形变化。结果：正常犬两种导联图形相似，均呈Ｒ（Ｒｓ）或ｒＳ型；无病理Ｑ波。ＳＴ段抬高、病理Ｑ波和Ｒ波丢失为急性右室心肌缺血和梗塞的敏感指标。在右室小范围缺血早期，仅ＨＶ３Ｒ～ＨＶ６ＲＳＴ段抬高（≥１ｍｍ）达诊断标准，并且抬高幅度始终超过同部位、同时间Ｗｉｌｓｏｎ导联。结论：ＨＣ导联右胸图形的特征性改变较Ｗｉｌｓｏｎ导联更利于右室梗塞的检出。     

静脉畸形、迂曲、狭窄时永久起搏导线置入的方法探讨

经静脉造影或观察导丝走形证实 6例患者存在静脉畸形、迂曲、狭窄 ,其中 5例高龄患者置入永久起搏器时 ,其上腔静脉系统迂曲、狭窄 ,无法使用起搏器穿刺套装内的导丝及鞘管将导线送到起搏部位 ,另 1例为永存左上腔静脉合并有右上腔静脉缺如。试用 175cm 0 .0 35长导丝以及 6 8FINPUT鞘替代普通起搏器穿刺套装。结果 :使用175cm 0 .0 35长导丝以及 6 8FINPUT鞘顺利地将起搏导线送入右心房中下部 ,安全地完成置入手术 ,无并发症。结论 :一旦送入导线或导丝困难 ,应积极地进行血管造影 ,不应盲目的推送 ,使用 175cm长导丝增加支撑力 ,结合IN PUT鞘管通过狭窄或纡曲延长的血管段 ,给起搏导线提供一个光滑的通道 ,可顺利的将起搏导线送入心房及心室。     

Amiodarone reduces procedures and costs related to atrial fibrillation in a controlled clinical trial.

BACKGROUND: Atrial fibrillation is the most common sustained cardiac arrhythmia, and engenders significant health care costs. The impact of various treatment options for atrial fibrillation on hospital costs has not been evaluated in a randomized trial. METHODS: We analysed 1-year follow-up data on 392 patients randomized to low dose amiodarone (200 mg. day(-1)) or alternative first-line therapy (sotalol or propafenone) in a multicentre trial (Canadian Trial of Atrial Fibrillation, CTAF). RESULTS: Patients in the amiodarone group had fewer electrical cardioversions (65 vs 109 for patients in the sotalol/propafenone group, P<0.0001), and pacemaker insertions (4 vs 11, P=0.07). The average amiodarone patient spent fewer days in hospital (0.47 vs 0.97, P=0.01), and incurred lower costs ($532 vs $898, P=0.03), for admissions where atrial fibrillation was the admitting diagnosis. Average total hospital costs per patient for all admissions, as well as average combined hospital and physician costs per patient, showed wide variations within the treatment arms and were not significantly different between groups. CONCLUSION: For patients in whom antiarrhythmic drug therapy is indicated, low dose amiodarone significantly reduces atrial fibrillation-related costs by reducing the number of atrial fibrillation-related procedures.     

Electrocardiographic evidence of ischemia during ventricular paced rhythms

Exercise-induced electrocardiographic (ECG) changes are the most widely recognized noninvasive means for detecting myocardial ischemia. The specificity of these changes depends on the normalcy of the resting ECG. Right ventricular pacing produces major QRS and ST-T changes very similar to those of complete left bundle-branch block. They alter the resting ECG such that ischemic changes are considerably difficult to detect. Because of these resting abnormalities, ECG changes during treadmill exercise testing usually do not facilitate the diagnosis of ischemia or coronary artery disease. The following are two cases of ischemic ECG changes that occurred during right ventricular pacing. To our knowledge, there have been no reports of the classic ECG changes of ST-segment depression suggestive of ischemia which occurred during right ventricular pacing and which were discemible from the resting ECG changes.