起搏后体位性低血压

观察7条狗起搏前后从卧位变为站位时的血流动力学变化。起搏后起立时平均动脉压平均下降28％,是正常时(13％)的二倍,并且恢复时间明显延长(P<0.01)。实验表明起搏前后狗的体位性低血压代偿机制不同,正常时起立时心输出量增加20％左右,心率平均增加24％,而每搏输出量在开始阶段常减少,有的在整个站立过程中减少。心率在提高心输出量,代偿体位性低血压中起着重要作用。起搏后由于心率固定不变,因而出现明显的体位性低血压。提高起搏频率可改善体位性低血压。     

超声评估急重症患者容量状态研究进展

循环不稳定是急重症患者常见急症之一,快速评估其容量状态是指导治疗的关键。检测中心静脉压（CVP）是目前临床评估容量负荷的较常用方法,但为有创操作,且存在较多近远期并发症。超声作为无创检查已广泛应用于监测血流动力学,近年来,采用急诊超声评估患者容量状态并指导液体治疗日益普及。本文对超声评估急重症患者容量状态的应用进展进行综述。     

创伤性肺栓塞应用华法林治疗前后的血流动力学变化研究

目的：探讨创伤性肺栓塞患者使用华法林治疗后,血流动力学变化特征。方法将该院2013年10月—2014年10月收纳的36例创伤性肺栓塞患者设为观察组;另选取同期于该院接受体检的36名健康体检者设为对照组。对比两组研究对象不同时期的血流动力学变化值。结果相较于对照组,观察组患者治疗前MAP、CI、SV、SI、PAWP明显更低,HR、SVR、TFC、PVR明显更高,组间对比差异有统计学意义（P＜0.05）。结论华法林治疗创伤性肺栓塞会引起血流动力学变化,临床可根据该监测指标对患者对患者病情与治疗紧张进行准确评估。     

重组人心钠肽治疗急性心力衰竭的临床研究

目的：探讨重组人心钠肽治疗急性心力衰竭疗效。方法：对自2011年5月～2013年2月我院收治的急性心力衰竭患者应用重组人心钠肽治疗,于用药前后监测患者的血流动力学参数。结果：66例患者59例症状缓解,显效27例,有效32例,无效7例,有效率89．39％。结论：重组人心钠肽是治疗急性心力衰竭疗效可靠的药物,安全性高。     

瑞舒伐他汀对脑梗塞患者脑血流动力学的影响

目的 探讨瑞舒伐他汀对脑梗塞患者脑血流动力学的影响效果.方法 选择我院2013年8月至2014年2月收治的80例脑梗塞患者为研究对象,随机分为对照组40例,观察组40例,对照组行常规抗血小板聚集、营养脑神经药物治疗,观察组在常规治疗基础上,加用瑞舒伐他汀治疗,对两组患者行多普勒超声检查,对比两组患者的脑血流动力学状况.结果 观察治疗后双侧大脑动脉Vm为(62.35±15.68) cm·s-1,双侧大脑动脉Vs为(88.62±25.31)cm·s-1,双侧大脑动脉PI为(0.63±0.31),对照组治疗后双侧大脑动脉Vm为(57.51±12.56) cm·s-1,双侧大脑动脉Vs为(80.51±21.54) cm·s-1,双侧大脑动脉PI为(0.73±0.51),差异有统计学意义(P＜0.05).结论 对脑梗塞治疗时,加用瑞舒伐他汀,可显著改善患者脑血流动力学,能帮助患者的病情恢复,值得临床进一步推广使用.     

Cardiovascular Effects of Medical Marijuana: A Systematic Review

Utilization of marijuana as a medicinal agent is becoming increasingly popular, and so far, 25 states have legalized it for medical purposes. However, there is emerging evidence that marijuana use can result in cardiovascular side effects, such as rhythm abnormalities, syncope/dizziness, and myocardial infarction, among others. Further, there are currently no stringent national standards or approval processes, like Food and Drug Administration (FDA) evaluation, in place to assess medical marijuana products. This review includes the largest up-to-date pooled population of patients with exposure to marijuana and reported cardiovascular effects. Although purported as benign by many seeking to advance the use of marijuana as an adjunctive medical therapy across the country, marijuana is associated with its own set of cardiovascular risks and deserves further definitive study and the same level of scrutiny we apply in research of all other types of medications. When used as a medicinal agent, marijuana should be regarded accordingly, and both clinical providers and patients must be aware of potential adverse effects associated with its use for early recognition and management.     

Astragalus polysaccharide attenuates isoproterenol-induced cardiac hypertrophy by regulating TNF-α/PGC-1α signaling mediated energy biosynthesis

We previously reported that Astragalus polysaccharide (APS) extracted from Chinese medicine Astragalus membranaceus (Fisch.) Bge, attenuates hypertrophy of neonatal rat ventricular myocytes (NRVMs) induced by isoproterenol (Iso). The present study was designed to investigate the effects and the possible mechanism of APS on Iso-induced hypertrophy in rats and NRVMs with focus on tumor necrosis factor α (TNF-α)/peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) signaling mediated energy biosynthesis. 36-Week old rats were randomly divided into 3 groups: (1) Control, rats received vehicle; (2) Iso, rats received isoproterenol injections; (3) Iso+APS, rats received isoproterenol injections and APS. NRVMs were divided into similar groups as rats. The results showed that combination of APS with Iso significantly attenuated the pathological changes, reduced the ratios of heart weight/body weight (HW/BW) and left ventricular weight/BW (LVW/BW), improved the cardiac hemodynamics, down-regulated mRNA and protein expression of atrial natriuretic peptide (ANP), increased the ratios of ATP/ADP and ATP/AMP, and decreased the content of free fatty acid (FFA) in heart tissue of rats compared with Iso alone. In addition, pretreatment with APS significantly decreased the surface area and protein content, down-regulated mRNA and protein expression of ANP, increased the ratios of ATP/ADP and ATP/AMP, and decreased the content of FFA in NRVMs compared with Iso alone. Furthermore, APS increased the protein expressions of ATP5D, the σ subunit of ATP synthase, PGC-1α and pyruvate dehydrogenase kinase 4 (PDK4) in tissue and NRVMs respectively and inhibited the production of TNF-α in serum and culture medium compared with Iso alone. The results suggested that APS attenuates Iso-induced cardiac hypertrophy through regulating TNF-α/PGC-1α signaling mediated energy biosynthesis.     

Improvement in Hemodynamics After Methylene Blue Administration in Drug-Induced Vasodilatory Shock: A Case Report

Introduction

The purpose of this study is to describe a case where methylene blue improved hemodynamics in a poisoned patient.

Case Report

This is a single case report where a poisoned patient developed vasodilatory shock following ingestion of atenolol, amlodipine, and valsartan. Shock persisted after multiple therapies including vasopressors, high-dose insulin, hemodialysis, and 20% intravenous fat emulsion. Methylene blue (2 mg/kg IV over 30 min) was administered in the ICU with temporal improvement as measured by pulmonary artery catheter hemodynamic data pre- and post-methylene blue administration. Within 1 h of methylene blue administration, systemic vascular resistance improved (240 dyn s/cm5 increased to 1204 dyn s/cm5), and vasopressor requirements decreased with maintenance of mean arterial pressure 60 mmHg.

Discussion

Methylene blue may improve hemodynamics in drug-induced vasodilatory shock and should be considered in critically ill patients poisoned with vasodilatory medications refractory to standard therapies.     

肝右静脉与下腔静脉位置对布-加综合征产生机制的影响

目的探讨不同肝右静脉与下腔静脉夹角变化对布-加综合征患者下腔静脉隔膜发生机制的影响。方法运用Mimics软件对临床磁共振成像血管造影下腔静脉和主要肝静脉图像进行三维实体模型重建,测得正常模型下腔静脉与肝右静脉夹角为56°。在保持模型基本结构不变基础上,分别构建肝右静脉与下腔静脉夹角为30°和120°的模型,并数值模拟计算3个模型的壁面剪切力、壁面压强、速度分布。结果 3个模型壁面压强、壁面剪切力差异显著。与正常人56°模型相比,30°模型有较高的壁面压强和较低的血液流速,120°模型有较低的壁面剪切力和血液流速,并伴随有涡流的出现,这些血流动力学因素的改变更易于血栓的形成。56°模型血管内血流流速最快。结论对下腔静脉与肝右静脉血液流场的数值模拟有助于了解布-加综合征的发病机制,提高下腔静脉阻塞隔膜形成风险的预测,为治疗提供理论依据。     

急性中型颅脑损伤后脑血流动力学改变的经颅多普勒超声诊断

目的 探讨经颅多普勒超声(TCD)对中型颅脑损伤早期诊断中的作用及脑血流动力学特点。方法 对40例脑挫伤患者应用TCD观察脑血流动力学改变，并与正常对照组40名健康者进行比较。结果 40例患者中脑血流异常3l例(占77.5％)，异常患者中26例(83.9％)出现脑血流速度增快，7例(22．6％)出现脑血流速度减慢，13例(41.9％)出现搏动指数(PI)增高，收缩峰高尖频谱，以椎基底动脉为主；有3例(9.7％)颅内外各动脉血流速度广泛增快。中型颅脑损伤脑血液流速各期均呈增高趋势。结论 TCD可以早期发现颅脑损伤时的脑血流动力学的异常，是动态观察脑血流动力学变化的理想方法和手段。