氨基胍对糖尿病大鼠心脏功能及心肌超微结构的影响

目的 :探讨非酶糖化抑制剂 氨基胍 (amin oguanidine ,AG)对链尿佐菌素 (streptozotocin ,STZ)糖尿病大鼠心肌的保护作用 ,为糖尿病心肌病的防治提供参考。方法 :建立STZ糖尿病大鼠模型 ,随机分为对照组、糖尿病组和氨基胍治疗组 ,AG剂量为15 0mg·kg-1·d-1。 12周时测定大鼠血清果糖胺含量、心脏重量指数、左室内压最大上升和下降率 (±dp dtmax)值 ,电镜观察心肌超微结构 ,测量心肌毛细血管基底膜厚度。结果 :糖尿病组大鼠血清果糖胺含量、心脏重量指数明显增高 ,±dp dtmax降低 ;超微结构显示心肌肌原纤维排列紊乱 ,线粒体肿胀变性 ,间质胶原增生 ,微血管内皮细胞肿胀、基底膜明显增厚。氨基胍治疗组血清果糖胺含量降低、心脏重量指数明显下降、±dp dtmax 值上升 ,微血管基底膜增厚减轻 ,间质胶原减少 ,心肌细胞超微结构异常减轻。结论 :糖尿病时存在心脏功能异常、心肌肥厚和超微结构的改变 ,早期应用AG在一定程度上可阻抑糖尿病心肌病变的发展。     

儿童先天代谢异常伴发的肥厚型心肌病

儿童先天代谢异常是导致肥厚型心肌病（HCM）的重要病因, 掌握每种疾病的特征性表现有助于正确的诊断及鉴别诊断。多数先天代谢异常伴发HCM属于常染色体隐性遗传,少数为常染色体显性遗传X连锁遗传方式,部分线粒体病呈母系遗传。常规心电图、超声心动图等心脏检查即可以为部分疾病的基础病因找到诊断线索。随着酶替代疗法等新的治疗方法的不断进步,加强心脏评估,恰当地针对原发病治疗,多学科协同合作将为越来越多的患者生存提供可能。     

Prognostic predictive value of TLR4 polymorphisms in Han Chinese population with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease and is an important cause of sudden death in patients of all ages. The aim of this study was to find out whether Toll-like receptor-4 (TLR4) polymorphism is associated with HCM. To explore the association between TLR4 gene polymorphisms and HCM, 486 HCM patients and 214 healthy controls were enrolled in a case–control study of Chinese Han population. Two single nucleotide polymorphisms (SNPs) in the promoter region of TLR4 gene, ?728G > C (rs11536865) and ?2081G > A (rs10983755), were genotyped by PCR restriction fragment length polymorphism (PCR-RFLP). The associations between TLR4 SNPs and overall survival (OS) of HCM patients were analyzed by the Kaplan–Meier estimation method and Cox proportional hazards regression analysis. Serum TLR4 level was determined by ELISA. Our results showed that the C allelic frequency of ?728G > C and A allelic frequency of ?2081G > A were higher in HCM patients than those in controls (P < 0.001). The ratios of genotype frequencies for both SNPs were associated with HCM susceptibility under three genetic models (P < 0.01). Two SNPs were also associated with the OS in HCM patients (P < 0.001). The CC genotype of ?728G > C and AA genotype of ?2081G > A were associated with poor prognosis of HCM (P < 0.001). Moreover, HCM patients had a higher serum TLR4 level compared with the controls (242.6 pg/ml versus 135.7 pg/ml, P = 0.027). In addition, significant associations were observed between CC genotype of ?728G > C or AA genotype of ?2081G > A and plasma TLR4 level (P < 0.01). The results of this study indicated that TLR4 polymorphisms may be a genetic susceptibility factor for HCM in the Han Chinese population.     

Fragmented ECG as a Risk Marker in Cardiovascular Diseases

Various noninvasive tests for risk stratification of sudden cardiac death (SCD) were studied, mostly in the context of structural heart disease such as coronary artery disease (CAD), cardiomyopathy and heart failure but have low positive predictive value for SCD. Fragmented QRS complexes (fQRS) on a 12-lead ECG is a marker of depolarization abnormality. fQRS include presence of various morphologies of the QRS wave with or without a Q wave and includes the presence of an additional R wave (R’) or notching in the nadir of the R’ (fragmentation) in two contiguous leads, corresponding to a major coronary artery territory. fQRS represents conduction delay from inhomogeneous activation of the ventricles due to myocardial scar. It has a high predictive value for myocardial scar and mortality in patients CAD. fQRS also predicts arrhythmic events and mortality in patients with implantable cardioverter defibrillator. It also signifies poor prognosis in patients with nonischemic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and Brugada syndrome. However, fQRS is a nonspecific finding and its diagnostic prognostic should only be interpreted in the presence of pertinent clinical evidence and type of myocardial involvement (structural vs. structurally normal heart).     

Cardiac manifestations of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating condition. It carries a high mortality rate, with 12% of patients dying before reaching the hospital. Aside from its neurological morbidities, SAH is associated with significant medical complications. Cardiac manifestations are common and can impact morbidity and mortality in SAH patients. This article will discuss the cardiac manifestations of SAH.     

Live/Real Time Three‐Dimensional Transesophageal Echocardiographic Assessment of Ventricular Septal Volume and Mass before and after Myectomy in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.