人造机械瓣心音的分析研究

在一些致命性心脏病的诊断中,心音听诊是最有效也是应用得最成功的手段之一.鉴于目前机械瓣的使用非常普遍,研究简单有效的机械瓣病变判别方法对于临床诊断来讲具有重要意义.运用希尔波特-黄变换(HHT),针对不同的机械瓣心音进行分析,并设计一种基于Hilbert边界谱特征的提取方法,结合线性判别分析(LDA),对不同的机械瓣心音进行分类.同时,与基于局部最优基特征的分类器分类结果进行比较.分析结果表明,机械瓣心音的各阶Hilbert边界谱具有非常明显不同的分布,基于HHT的分类器识别率达到了97.3％,较基于局部最优基特征分类器的识别率(91.3％)更高.对于人造机械瓣心音而言,HHT是一种有效的分析处理手段.     

人工心瓣含硅热解炭涂层的微观结构

为了研究人工心瓣含硅热解炭涂层的微观结构,利用准稳态流化床反应装置制备出了含硅热解炭涂层,利用X射线衍射(XRD)、X射线能谱仪(EDS)、扫描电镜(SEM)、透射电镜(TEM)和偏光显微镜(PLM)对涂层微观结构进行了表征.结果表明,该涂层材料只有乱层结构热解炭和β型碳化硅两种物相,主要由直径为300 nm ～1μm的球形颗粒状碳结构组成,球形颗粒之间由片层状碳结构紧密相连,偶尔会形成闭合孔洞(直径约为0.1 ～1μm).涂层中硅元素宏观均匀分布且含量适中(6.48 wt％),直径约6～8nm的β型碳化硅晶粒无规则取向分布且存在微观尺度的集聚现象.含硅热解炭涂层的这些结构特征决定了其均匀致密、宏观各向同性的特性.     

A Physical Model Describing the Mechanism for Formation of Gas Microbubbles in Patients with Mitral Mechanical Heart Valves

This study was aimed at developing a physical model, supported by experimental observations, to describe the formation and growth of microbubbles seen in patients with mitral mechanical heart valves (MHV). This phenomenon, often referred to as high intensity transient signals (HITS), appears as bright, intense, high-velocity and persistent echoes detected by Doppler ultrasonography at the instant of closure. The long-term clinical implications of HITS has yet to be determined. However, there are reports of a certain degree of neurological disorder in patients with mitral MHV. The numerical analysis has shown the existence of a twofold process (1) nucleation and (2) microbubble growth as a result of cavitation. While mild growth of nuclei is governed by diffusion, explosive growth of microbubbles is controlled by pressure drop on the atrial side of mitral MHV. It was demonstrated that there exist limits on both microbubble size and regurgitant velocity, above which microbubbles grow explosively, and below which growth is almost nonexistent. Therefore, prevention of excessive pressure drops induced by high closing velocities related to the dynamics of closure of mitral MHV may offer design changes in the future generations of mechanical valves. © 1999 Biomedical Engineering Society. PAC99: 8763Df, 8710+e, 8719Uv, 8780Rb, 4755Dz, 8719La     

Experimental Observation on Antithrombotic Property of A New Bileaflet Mechanical Heart Valve in Sheep

Objective ： To observe the antithrombotic property of a new all-pyrolytic carbon bileaflet mechanical heart valve so as to provide evidence for clinical practice. Methods： 15 sheep underwent mitral valve replacement （MVR） with this new mechanical valve. Each animal was placed on cardiopulmonary bypass. All of the sheep were given in an anticoagulation protocol and followed for three months. Final studies were performed on all animals surviving for more than 12 weeks. Results ： 10 sheep died within 48 h after operation, 5 sheep survived. The long-term survivors were killed for autopsies,2 sheep were killed after 1 week, 1 after 12 weeks and 2 after two and half years. Pathological examination of 10 sheep which died early after operation revealed that there was neither evidence of thrombosis nor any failure of the mechanical valve. Autopsy studies in the 5 long-term survivors revealed that the sewing ring was covered by a thin layer of microthrombi consisted most of platelets and fibrin after 1 week. The sewing ring was covered by a tissue layer, with partial organized microthrombi and endothelialization after 12 weeks. Two and half years after operation, the complete endothelialization presented around the sewing ring without restriction of bileaflet motion. The tissue ingrowth tends to stop at the pyrolytic earbon-fabric interface on both surfaces of left atrium and ventricle. This study demonstrated that the new prosthetic heart valve had not promoted thrombosis and thrombembolism.     

双叶机械瓣膜不同植入角度对主动脉血流动力学的影响

目的 研究双叶机械瓣膜（bileaflet mechanical heart valve,BMHV）不同植入角度对升主动脉旋动流的影响。方法 基于1位健康自愿者主动脉CT图像,采用计算机数值模拟方法,在定常流条件下,比较研究4种不同瓣膜植入角度（0°、45°、90°和135°）对主动脉旋动流的影响。结果 BMHV植入会严重干扰主动脉内的旋动流,影响升主动脉处的旋动流结构和旋动流强度分布,在瓣膜下游出现扰流区。135°植入角度对旋动流的破坏最大,产生逆向旋动区域最多;0°和45°角植入对旋动流破坏相对较小。植入角为0°时主动脉低壁面剪切应力（<0.5 Pa）所覆盖面积最小。结论 植入角度为0°~45°时,BMHV对升主动脉内旋动流破坏相对较小。因此,对不同患者而言,应根据其主动脉（包括主动脉窦）的空间几何构型进行个性化选择,植入角度可在0°~45°之间确定。     

肾病综合征合并肾静脉血栓应用阿加曲班疗效评价

目的 探讨肾病综合征合并肾静脉血栓治疗中应用选择性抗凝剂阿加曲班的临床疗效。方法 选择我院2015年3月~2018年2月诊断为肾病综合征合并肾静脉血栓患者56例,采用随机抽样法分为两组,对照组采用低分子肝素抗凝治疗,研究组在对照组治疗基础上联合阿加曲班治疗,记录两组血尿素氮、肌酐、血白蛋白、24 h尿蛋白定量、血小板、纤维蛋白原、甘油三酯结果,进行对比分析。结果 研究组总有效率高于对照组（P＜0.05）;两组患者治疗后Cr、Upro、ALB、BUN指标较治疗前有改善,研究组改善情况优于对照组（P＜0.05）。两组患者治疗前后TG、FIB、PLT无明显变化（P＞0.05）。两组患者均未出现与抗凝相关的严重并发症。结论 由于阿加曲班选择性抗凝作用、出血风险小,阿加曲班联合低分子肝素治疗肾病综合征合并肾静脉血栓疗效明显,安全可靠。     

Clinical cure of severe, early onset preeclampsia with low molecular weight heparin therapy in primigravida with hyperreactio luteinalis and thrombophilia

Inherited thrombophilias, suggested to be risk factors for ovarian hyperstimulation syndrome and known to be associated with venous thromboembolism during pregnancy, may also increase the risk for preeclampsia (PE). We describe the case of a 29-year-old woman with primary infertility with no history of thrombosis, hypertension or renal disorders. In her first pregnancy, achieved by frozen embryo transfer, she developed severe early-onset (23rd gestational week) PE with heavy proteinuria, and at the same time was found to have enlarged ovaries with hyperreactio luteinalis. After admission we found that she was a heterozygotic carrier of the factor V Leiden mutation. After administering low molecular weight heparin (LMWH) therapy, her blood pressure normalized, proteinuria diminished and her d-dimer values returned to that of a normal pregnant level. The fetus grew normally. Her ovaries normalized during the pregnancy, as determined by ultrasound examinations. At term she delivered spontaneously a normal weight, healthy girl. Previously, only prophylactic LMWH, in subsequent pregnancy, have been administered in patients with thrombophilia and a history of severe PE. We describe a case of spontaneous hyperreactio luteinalis, where the clinical characteristics of PE improved after beginning LMWH therapy in severe, very early onset PE. Inherited thrombophilia, spontaneous hyperreactio luteinalis and PE may be associated phenomena.     

保留瓣下结构的二尖瓣机械瓣下游湍流强度的体内定量研究

目的　了解保留瓣下结构对机械瓣下游血流动力学的影响 ,为临床上选择合理术式提供科学依据 .方法　采用与计算机图像分析相结合的彩色多普勒技术 ,对一组保留瓣下结构的不同类型机械瓣置换术后病人瓣膜下游相对扰动强度 (Relativeturbulentintensity,Irel)等指标进行检测与分析 .结果　无论保留后瓣或全瓣瓣下结构 ,单叶机械瓣 (单叶瓣 )下游Irel均较双叶机械瓣 (双叶瓣 )高 (p <0 .0 5 ) .对于双叶瓣 ,保留后瓣瓣下结构组 (保留后瓣组 )和未保留瓣下结构组 (未保留组 )之Irel均低于保留全瓣瓣下结构组 (保留全瓣组 ) (p<0 .0 5 ) ;而对于单叶瓣 ,保留后瓣组Irel低于保留全瓣组 (p <0 .0 5 ) ,同时高于未保留组 (p <0 .0 5 ) .结论　保留瓣下结构可引起跨瓣血流湍流强度增大 ,尤见于全瓣瓣下结构均保留者 ,而且单叶瓣甚于双叶瓣     

地屈孕酮联合低分子肝素钙治疗先兆流产患者的效果

目的 探讨地屈孕酮联合低分子肝素钙治疗先兆流产患者的效果。方法 选取2017年4月~2018年12月我院收治的先兆流产患者80例,按照随机数字表法分为对照组和研究组,各40例。对照组采用地屈孕酮进行治疗,研究组在对照组基础上联合低分子肝素钙进行治疗,比较两组妊娠结局及所产出新生儿不良结局。结果 研究组早产、流产、正常足月妊娠占比分别为12.50%、7.50%、80.00%,优于对照组的30.00%、17.50%、52.50,差异有统计学意义（P＜0.05）。研究组新生儿畸形、喘息急促、新生儿偏大、足月体重轻、正常新生儿占比分别为5.00%、10.00%、0、2.50%、82.50%,优于对照组的15.00%、22.50%、5.00%、10.00%、47.50%,差异有统计学意义（P＜0.05）。结论 地屈孕酮联合低分子肝素钙治疗先兆流产患者能够有效地改善患者的妊娠结局,减少新生儿畸形、喘息急促、新生儿偏大、足月体重轻等不良结局。     

含有镍钛合金丝的PET纺织瓣膜有限元分析及体外流体力学测试

目的 利用有限元方法分析径向织入镍钛金属丝的涤纶(polyethylene terephthalate, PET)基纺织瓣膜力学性能,结合体外血流动力学测试,分析金属丝数量和分布形式对PET瓣膜流体动力学性能的影响。方法 使用建模软件构建在径向方向上具有不同数量和分布的金属丝PET瓣膜和无金属丝PET瓣膜三维几何模型;根据文献和实验数据给定PET瓣膜和金属丝的材料属性;使用体外脉动流实验得到PET瓣膜的跨瓣压差曲线作为边界条件;利用有限元分析软件研究瓣膜在心动周期内的应力分布;通过体外脉动流实验评估金属丝瓣膜的流体力学性能。结果 有限元分析结果表明,径向织入镍钛金属丝可以增强对PET纺织瓣膜的支撑作用,金属丝均匀分布的瓣膜在瓣叶腹部区域的支撑力及作用区域随着金属丝数量增加而增大,金属丝分布在两侧位置的情况类似。金属丝的织入一定程度上改善PET瓣膜上的应力集中。脉动流实验结果表明,织入金属丝PET瓣膜开闭形态的稳定性、有效开口面积、反流分数和跨瓣压差等指标均优于无金属丝的纯PET瓣膜。结论 在PET纺织瓣膜的径向方向织入金属丝可以有效减少心动周期内PET纺织瓣膜上的应力集中,降低PET纺...     

Clinical Outcomes of Transcatheter Aortic Valve Implantation for Native Aortic Valves in Patients with Low Coronary Heights

PurposeAcute coronary occlusion is a rare but fatal complication that may occur during trans-catheter aortic valve implantation (TAVI) and appears more frequently in patients with low coronary heights. We evaluated the feasibility of self-expanding valves in patients with low coronary heights undergoing TAVI.Materials and MethodsTAVI for native aortic valve stenosis was conducted in 276 consecutive patients between 2015 and 2019 at our institute. Using multi-detector computed tomography (MDCT), information on the aortic valve, coronary arteries, and vascular anatomy in 269 patients was analyzed. Patients with low coronary heights were defined as those with coronary heights of 10 mm or less during MDCT analysis.ResultsAmong the 269 patients, 29 (10.8%) patients had coronary arteries with low heights. The mean coronary height was 8.9±1.2 mm in the left coronary artery. These patients with low coronary heights were treated with self-expandable (n=28) or balloon-expandable (n=1) valves. Prophylactic coronary protection with a guidewire, balloon, or stent prepositioned down at-risk coronary arteries was not pursued in all patients. No acute coronary occlusion occurred in any of these patients during TAVI. Five patients (17.9%) died during follow-up (average of 553.8 days), including four from non-cardiogenic causes and one from a cardiogenic (aggravation of heart failure) cause.ConclusionA considerable number of patients with low coronary heights were observed among TAVI candidates in this study. Use of a self-expandable valve may be feasible for successful TAVI without acute coronary occlusion in patients with low coronary heights.     

慢性心力衰竭患者窦性心率震荡的临床意义

目的探讨慢性充血性心力衰竭（CHF）患者窦性心率震荡（HRT）与心功能程度的关系。方法慢性心衰患者（CHF组）85例,全部病例按纽约心脏病协会（NYHA）心功能分级,分为轻度CHF组（心功能Ⅱ级）45例和重度CHF组（心功能Ⅲ～Ⅳ级）40例。另选同期心功能正常的42例作为对照组。所有入选者均接受24h动态心电图检查,分别计算窦性心率震荡的初始值（TO）、震荡斜率（TS）,并进行统计学分析。结果3组的TO均值比较,重度CHF组与对照组比较差异有统计学意义（P〈0．01）;轻度CHF组与对照组比较差异有统计学意义（P〈0．05）;3组间的鸭均值组间两两比较差异均有统计学意义（P〈0．01）。结论伴随CHF患者程度加重,HRT现象明显变钝减弱．其变化可能与自主神经的变化有关。     

心脏机械瓣膜置换围手术期患者应用健康教育路径图表的效果观察

目的 观察接受心脏机械瓣膜置换患者在围手术期应用健康教育路径图表的临床效果。方法 随机抽样法选择2016年1月~2017年1月在我科接受心脏机械瓣膜置换的30例患者作为对照组,按照常规执行健康教育。随机抽样法选择2017年2月~2018年3月,在我科接受心脏机械瓣膜置换的30例患者作为观察组,按照健康教育路径图表进行健康教育。比较两组患者的平均住院天数,平均住院费用,疾病知识知晓分数及患者满意度分数。结果 观察组疾病知识理想值达标率为93.33%,高于对照组的70.00%,差异有统计学意义（P＜0.05）;观察组出院满意度达标率为96.67%,高于对照组的73.33%,差异有统计学意义（P＜0.05）;观察组平均住院天数（19.37±1.67）d,平均住院费用（55656.71±4405.48）元,均低于对照组的平均住院天数（22.5±3.95）d,平均住院费用（65788.83±3515.10）元,统计学意义显著（P＜0.01）;观察组患者疾病知识知晓分数（8.33±1.27）分,出院患者满意度分数（98.60±2.40）分,均高于对照组的疾病知识知晓分数（6.80±1.89）分,出院患者满意度分数（95.10±4.358）分,统计学意义显著（P＜0.01）。结论 健康教育路径图表的应用有助于缩短疾病恢复进程,节省住院费用,减轻患者压力,提高了出院患者满意度达标率,相关知识掌握程度的提高,对疾病远期恢复有正面影响。     

心理干预对冠心病介入治疗患者的影响

目的 探讨心理干预对冠心病介入治疗患者的影响.方法 对68例冠心病介入治疗患者,随机分为两组,干预组34例,对照组34例,在手术前后对干预组进行综合心理干预,并采用SDS和SAS评定两组患者的情绪变化.结果 术前两组患者SDS和SAS评分无显著性差异,心理干预后干预组的抑郁焦虑较对照组明显改善(P＜0.01),且并发症明显少于对照组.结论 心理干预可明显的减轻冠心病介入治疗患者的抑郁焦虑,并且可显著减少术后并发症的发生,对保证手术的顺利进行具有重要意义.     

Pathogenicity of human anti-platelet factor 4 (PF4)/heparin in vivo: generation of mouse anti-PF4/heparin and induction of thrombocytopenia by heparin

Heparin-induced thrombocytopenia/thrombosis (HIT) is a severe thrombotic disorder that occurs in ≈1% of patients treated with heparin. Affected patients commonly develop antibodies that recognize PF4/heparin complexes that may form on the surface of activated platelets and on the endothelium. However, it has not been established that anti-PF4/heparin antibodies are responsible for the clinical manifestations of HIT. To address this issue, we employed a recently developed model of active immunity to study the effect of IgG anti-PF4/heparin antibody in vivo. In previous studies we have shown that it is possible to induce autoimmune diseases such as systemic lupus erythematosus (SLE), anti-phospholipid syndrome (APS) or vasculitis in naive mice by active immunization with anti-DNA, anti-cardiolipin and anti-neutrophil cytoplasmic antibodies, respectively. Immunized animals develop anti-idiotypic antibodies (Ab₂) and, after 2–4 months, anti-anti-idiotypic antibodies (Ab₃). Ab₃s generated in this manner often simulate the binding activity of Ab₁ and their expression correlates with the development of specific clinical manifestations typical of the respective human disease. Based on this experience, naive BALB/c mice were immunized with IgG anti-PF4/heparin antibodies isolated from two patients with HIT. The actively immunized mice developed mouse anti-PF4/heparin antibody (Ab₃). Administration of unfractionated heparin, but not low molecular weight heparin (LMWH), to the actively immunized animals induced thrombocytopenia by day 4 of drug exposure. There was no evidence of thrombosis. The results of this study support the importance of anti-PF4/heparin antibodies in the pathogenesis of HIT. Further, this model may help to elucidate the factors responsible for thrombosis as well as providing means to assess new treatment options for patients with this disorder.     

希氏束起搏在慢性心力衰竭患者中的应用

希氏束-浦肯野纤维是心脏传导系统的重要组成部分,希氏束起搏（HBP）是通过自身希氏束-浦肯野纤维系统传导,具有保留心脏机械同步性的优势,是目前最生理性的心脏起搏方式,可避免心室收缩的不同步,减少心力衰竭的发生。HBP分为选择性希氏束起搏和非选择性希氏束起搏。对于需要高比例心室起搏、右室起搏导致心功能恶化、因房颤合并心衰行房室结消融控制心室率以及部分符合CRT适应证的患者,希氏束起搏可显著改善心功能,本文就此进行阐述。     

Selective antimetastatic effect of heparins in preclinical human melanoma models is based on inhibition of migration and microvascular arrest

Use of heparin derivatives in several cancer types revealed that anticoagulant therapies have a beneficiary side effect: delay of tumor progression. Since there are no data on human melanoma, we have analyzed the effect of heparins in preclinical models. Neither unfractionated heparin (UFH), nor its low molecular weight derivative (LMWH) influenced in vitro or in vivo growth of HT168-M1 human melanoma cells. However, heparins significantly inhibited lung colony formation and liver metastasis development in the concentration range of 20–200 IU/kg, whereas recombinant hirudin was ineffective. The antimetastatic effect was due to an early (5–60 min) inhibition of tumor cell arrest in the lung microvasculature. Analysis of the molecular mechanism of the antimetastatic effect of heparins indicated a specific inhibition of tumor cell migration and matrix invasion. The presented experimental data suggest that heparins have specific antimetastatic effect in the case of human melanoma, which is independent from the coagulation cascade.