致心律失常性右室心肌病心力衰竭期的病理特点分析

目的 通过分析致心律失常性右室心肌病(ARVC)心力衰竭期的病理改变,以进一步了解其临床分期与病理表型的关系.方法 从2004-2007 年在阜外心血管病医院接受心脏移植的心力衰竭病例中,收集病理诊断为ARVC的受体心脏8例,测量心脏重量,评价左右心室心腔扩张、心肌细胞肥大、脂肪浸润、纤维化、附壁血栓和伴发心肌炎等指标,注意左心室受累情况,并进行病理分型.结果 8例中的7例为经典型(即右心室改变为主),1例为左优势型(左心室改变为主),未见双室型病例.组织学均为纤维脂肪型,未见单纯脂肪型病例.经典型病例的右心室中、重度扩张,少数有室壁瘤形成,其中6例伴左心室受累,受累左心室轻、中度扩张,心肌广泛间质纤维化,部分病例伴替代性疤痕,而脂肪浸润量小,多局限于心外膜下.左心室心肌细胞肥大普遍.而左优势型的左心室重度扩张,弥漫间质纤维化和局部透壁性脂肪浸润.8例中3例左心室明显肥厚,3例查见双室附壁血栓,1例伴局灶性心肌炎.结论 ARVC心力衰竭期的左心室受累多见而严重,左心室间质纤维化突出,心肌细胞肥大明显,但脂肪替代少见和局限.左、右心室多扩张,可见附壁血栓,应注意与扩张型心肌病等鉴别.     

无保护左主干病变介入治疗的支架选择—BMS还是DES?

许多循证医学研究显示,经皮冠状动脉支架术(percutaneous coronary implantation procedure,PCI)(包括药物洗脱支架植入术和裸金属支架植入术)是治疗无保护左主干病变的一种安全、有效的方法。但临床治疗上同时也发现两种支架的明显不足之处。如何选择支架,使得无保护左主干患者获得最大收益/风险比是值得仔细考虑的问题。     

永存左上腔静脉与胎儿畸形的关系探讨

目的探讨永存左上腔静脉与胎儿畸形的关系及永存左上腔静脉的产前诊断价值。方法在我院行产前系统超声检查的7721例孕妇,以永存左上腔静脉胎儿为研究对象,超声检查胎儿生长径线和脏器结构,并随访结果。结果产前超声共发现永存左上腔静脉胎儿47例。41例经产后证实,6例失访。产后证实心脏畸形27例(65.9%),其中18例(43.9%)合并内脏异位,为内脏异位综合征,7例(17.1%)单纯心脏畸形,2例(4.9%)合并染色体畸形;5例(12.2%)单纯心外畸形;9例(22.0%)单纯PLSVC。胎儿畸形总发生率78.0%(32/41)。结论永存左上腔静脉胎儿常合并内脏异位畸形以及其他心内、心外畸形,永存左上腔静脉与胎儿畸形有密切的关系,是产前超声筛查胎儿畸形的有效标志,产前诊断永存左上腔静脉有重要的价值。     

胎儿左心房主要结构的增龄变化

目的观测不同胎龄胎儿左心房结构,分析其大小范围及变化规律,为临床疾病诊断及手术治疗提供形态学资料。方法将40例胎心标本按胎龄大小分为4组,对各组胎儿左心房内主要结构(左上、下肺静脉内径,右上、下肺静脉内径,左心房壁厚度,二尖瓣环长、长短径大小)进行观测比较,所得数据用SPSS系统处理。结果不同胎龄的平均值,左上、下肺静脉内径分别为0.41±0.18cm、0.38±0.13cm;右上、下肺静脉内径分别为0.44±0.14cm、0.43±0.14cm,心房壁厚度为0.05±0.02cm,二尖瓣环长、长短径分别为0.61±0.25cm、0.49±0.02cm。结论胎儿左心房各结构随胎龄增长呈正相关。     

X-Ray Image Review of the Bone Remodeling Around an Osseointegrated Trans-femoral Implant and a Finite Element Simulation Case Study

The insertion of an implant into a bone leads to stress/strain redistribution, hence bone remodeling occurs adjacent to the implant. The study of the bone remodeling around the osseointegration implants can predict the long-term clinical success of the implant. The clinical medial–lateral X-rays of 11 patients were reviewed. To eliminate geometrical distortion of different X-rays, they were converted into a digital format and geometrical correction was carried out. Furthermore, the finite element (FE) method was used to investigate how the bone remodeling was affected by the stress/strain distribution in the femur. The review of clinical X-rays showed cortical bone growth around the proximal end of the implant and absorbtion at the distal end of the femur. The FE simulation revealed the stress/strain distribution in the femur of a selected patient. This provided a biomechanical interpretation of the bone remodeling. The existing bone remodeling theories such as minimal strain and strain rate theories were unable to offer satisfactory explanation for the cortical bone growth at the implant side of the proximal femur, where the stress/strain level was much lower than the one in the intact side of the femur. The study established the correlation between stress/strain distribution obtained from FE simulations and the bone remodeling of the clinical review. The cortical bone growth was initiated by the stress/strain gradient in the bone. Through the review of clinical X-rays and FE simulations, the study confirmed that the bone remodeling in a femur with an implant was influenced by the stress/strain redistribution. The strain level and stress gradient hypothesis is presented to offer an explanation for the implanted cortical bone remodeling observed in this study.     

Expression of the chromatin remodeling factor Rsf-1 is down-regulated in breast carcinoma effusions

We recently identified Rsf-1, a chromatin-remodeling gene, as a potential oncogene that is frequently amplified and overexpressed in ovarian serous carcinoma, and demonstrated that its expression in carcinoma cells in effusions is associated with poor prognosis. In the present study, we assessed the clinical significance of Rsf-1 overexpression in breast carcinoma effusions. Formalin-fixed paraffin-embedded sections from 47 effusions were analyzed for Rsf-1 expression by immunohistochemistry. Matched primary tumors (n = 30) and solid metastases (n = 26) from 30 patients were additionally studied. Rsf-1 expression in tumor cells in effusions was analyzed for association with clinicopathologic parameters and survival. Rsf-1 protein expression was found in carcinoma cells in 34 (72%) of 47 effusions, 24 (80%) of 30 primary carcinomas, and 24 (92%) of 26 metastases. Rsf-1 immunoreactivity in effusions showed no association with HER-2 or hormone receptor status. Rsf-1 expression level was significantly lower in effusions compared with primary tumors (P = .026 and P = .011 for extent and intensity, respectively) and lymph node metastases (P = .023 and P = .013 for extent and intensity, respectively). Staining extent and intensity were both significantly lower in breast compared with ovarian carcinoma effusions (P = .001 for extent, P < .001 for intensity). Rsf-1 expression showed no association with survival. In conclusion, in contrast to ovarian carcinoma, Rsf-1 expression is down-regulated in breast carcinoma cells in effusions compared with the solid counterparts and has no prognostic role at this anatomic site.     

Mechanoelectric Feedback as a Trigger Mechanism for Cardiac Electrical Remodeling: A Model Study

Regional variation in ionic membrane currents causes differences in action potential duration (APD) and is proarrhythmic. After several weeks of ventricular pacing, AP morphology and duration are changed due to electrical remodeling of the transient outward potassium current (I _to) and the L-type calcium current (I _Ca,L). It is not clear what mechanism drives electrical remodeling. By modeling the cardiac muscle as a string of segments that are electrically and mechanically coupled, we investigate the hypothesis that electrical remodeling is triggered by changes in mechanical load. Contractile force generated by the sarcomeres depends on the calcium transient and on the sarcomere length. Stroke work is determined for each segment by simulating the cardiac cycle. Electrical remodeling is simulated by adapting I _Ca,L kinetics such that a homogeneous distribution of stroke work is obtained. With electrical remodeling, a more homogeneous shortening of the fiber is obtained, while heterogeneity in APD increases and the repolarization wave reverses. Our results are in agreement with experimentally observed homogeneity in mechanics and heterogeneity in electrophysiology. In conclusion, electrical remodeling is a possible mechanism to reduce heterogeneity in cardiomechanics induced by ventricular pacing.     

Remodeling of chick embryonic ventricular myoarchitecture under experimentally changed loading conditions

Adult myocardium adapts to changing functional demands by hyper‐ or hypotrophy while the developing heart reacts by hyper‐ or hypoplasia. How embryonic myocardial architecture adjusts to experimentally altered loading is not known. We subjected the chick embryonic hearts to mechanically altered loading to study its influence upon ventricular myoarchitecture. Chick embryonic hearts were subjected to conotruncal banding (increased afterload model), or left atrial ligation or clipping, creating a combined model of increased preload in right ventricle and decreased preload in left ventricle. Modifications of myocardial architecture were studied by scanning electron microscopy and histology with morphometry. In the conotruncal banded group, there was a mild to moderate ventricular dilatation, thickening of the compact myocardium and trabeculae, and spiraling of trabecular course in the left ventricle. Right atrioventricular valve morphology was altered from normal muscular flap towards a bicuspid structure. Left atrial ligation or clipping resulted in hypoplasia of the left heart structures with compensatory overdevelopment on the right side. Hypoplastic left ventricle had decreased myocardial volume and showed accelerated trabecular compaction. Increased volume load in the right ventricle was compensated primarily by chamber dilatation with altered trabecular pattern, and by trabecular proliferation and thickening of the compact myocardium at the later stages. A ventricular septal defect was noted in all conotruncal banded, and 25% of left atrial ligated hearts. Increasing pressure load is a main stimulus for embryonic myocardial growth, while increased volume load is compensated primarily by dilatation. Adequate loading is important for normal cardiac morphogenesis and the development of typical myocardial patterns. Anat Rec 254:238–252, 1999. © 1999 Wiley‐Liss, Inc.     

家庭无创正压通气在慢性左室心力衰竭中的疗效

目的:探讨家庭无创正压通气在慢性左室心力衰竭中的治疗作用.方法:选择2016年1月至12月于保定市第一医院就诊的51例慢性左室心力衰竭患者进行观察,根据患者是否同意使用呼吸机分为两组:对照组给予常规抗心力衰竭治疗,治疗组给予常规抗心力衰竭和家庭无创正压通气治疗,治疗1年后观察两组临床症状、动脉血氧分压(arterial partial pressure of oxygen,PaO2)、6分钟步行试验(6-minute walking test,6MWT)、脑钠肽(brain natriuretic peptide,BNP)水平、左室射血分数(left ventricular ejection fraction,LVEF).结果:治疗1年后,治疗组临床症状、PO2、6MWT、BNP水平、LVEF均有显著改善,明显优于对照组,差异有统计学意义(P<0.05).结论:家庭无创正压通气有助于改善慢性左室心力衰竭患者的心功能,维持心功能的稳定,提高患者生活质量.