心肌梗塞后泵功能的恢复及其机制的实验研究

造成大鼠不同范围的心肌梗塞(MI)后,动态观察不同时期的静息和容量负荷状态下泵功能恢复的规律及其代偿机制。结果证明:(1)梗塞范围(IS)小于左室的46%时,泵功能都有自动恢复的可能性。IS越小,恢复越快、越好。IS超过46%时未见恢复;(2)在IS相同的条件上,静息状态的泵功能远较负荷状态的泵功能恢复得好;(3)MI后,泵功能代偿机制的代偿效应与IS呈反比。如IS超过46%,任何代偿机制均难以发挥效应。     

经二尖瓣超声多普勒法与经肺动脉导管热稀释法测定心脏指数的一致性研究

目的比较与验证经食管超声心动图(TEE)经二尖瓣(MV)测定的二尖瓣置换术(MVR)患者心脏指数(CIMV)与肺动脉导管(PAC)热稀释法测定的心脏指数(CIPAC)间的一致性。方法选择择期在心肺转流(CPB)下行MVR或者双瓣置换术(DVR)患者25例,其中男性12例,女性13例,年龄25~78岁。将患者分为机械瓣膜组(M组,n=16)和生物瓣膜组(B组,n=9)。麻醉诱导气管插管后放置TEE探头,于CPB停止后15min(T1)、30 min(T2)、45 min(T3)、60 min(T4),关胸后5 min(T5)、10 min(T6)、15 min(T7)时测定经MV的CI(CIMV),同时在各时间点记录经Swan-Ganz导管测定的CI(CIPAC)。CIMV与CIPAC的一致性分析采用Bland-AltmanPLOT和MountainPLOT一致性检验,以及相关关系。结果 M组105对测量值,CIPAC测量值为1.50~3.60L/(min·m2)(2.42±0.43),CIMV值为1.44~5.98L/(min·m2)(2.94±0.87);平均偏差为-0.50 L/(min·m2),95%的一致性界限为-1.97~0.97L/(min·m2);回归方程ym=1.72+0.24xm(r=0.47,P0.000 1)。B组63对测量值,CIPAC值为1.90~4.00 L/(min·m2)(2.58±0.49),CIMV值为1.83~7.71L/(min·m2)(3.93±1.13);平均偏差为-1.30 L/(min·m2),95%的一致性界限为-3.10~0.50L/(min·m2)。回归方程yb=1.56+0.26xb(r=0.60,P0.000 1)。结论在MVR中,由TEE经人工二尖瓣测量的CIMV与经肺动脉导管热稀释法测量的CIPAC有较好的相关性,但不能相互替代,需要回归方程校正。     

血液粘度与心输出量的相关性研究

目的阐明血液粘度与心输出量存在着规律性的联系。方法在２０例正常人及８２例心脏病患者中，以锥板法测定不同切变率的全血粘度（加）、血浆粘度（仰），以二维超声心动图按改良Ｓｉｍｐｓｏｍ氏法测定心输出量（ＣＯ），所得数据进行直线相关回归分析。结果ＣＯ与Ｄｂ、ｏｐ均呈显著负相关。进一步将病例分组对照，以比较降低血粘度（甲组巾扩张阻力血管（乙组）两者对ＣＯ的影响：甲组静滴低分子右旋糖面３００ｍｌ加唤蛇抗栓酶 １． ｓｕ和口服抵克力得（Ｔｉｃｌｉｄ） ５００ｍｇ，每天卫次，用药两周；乙组静滴酚妥拉明（Ｒｅｇｉｔｉｍｅ）２０ｍｇ，每天 １次，用药两周。两组病例各在用药前及停药手１～５周每周测定一次ＣＯ，５次的ＣＯ均数作为该组治疗的平均心输出量水平。经对照检验：甲组在提高心输出量水平上有更明显的作用。结论血液粘度是影响心输出量比较稳定的因素，降粘治疗对增加心输出量是有效、平稳、持久的疗法。     

脉搏波法无创检测心输出量的实验研究

监测心输出量的变化,是观察判断心脏功能的重要血流动力学指标.作者应用TP—CBS型心血管血流参数检测仪,通过动物实验与临床常用的有创心输出量检测法——热稀释法及电磁流量计法进行同步测试比较,以验证这种无损伤脉波法对心输出量检测的准确性和可信性,为临床推广应用提供实验依据.通过16只犬的对照性测试结果,与热稀释法比较相关系数(r)在0.7～0.9之间.与电磁流量计法比较相关系数(r)在0.8～0.9之间,得到了较好的相关性.表明应用无创伤脉波法监测心输出量,对临床判断心功能有重要参考价值.     

心脏瓣膜病患者瓣膜置换术前后BNP浓度的变化

目的:观察心瓣膜置换术患者围手术期血浆B型钠尿肽(BNP)浓度的变化规律。方法:56例心瓣膜置换术患者按NYHA心功能标准分级,术前进行超声心动图检查,测量左室射血分数(LVEF),同时于术前、术后1天、3天、5天、7天、14天,分别测量血浆BNP浓度,分析术前BNP浓度与心功能的关系,以及围手术期BNP浓度变化趋势。结果:心瓣膜疾病患者术前心功能NYHA分级与BNP水平呈正相关(r=0.59,P<0.05)。术后BNP浓度急剧上升,24h达峰值(P<0.01)。术后3～7天明显下降,但仍略高于术前水平,术后14天明显下降且低于术前水平。结论:术前血浆BNP浓度与心功能状况明显相关,BNP浓度越高,心功能越差。术后早期BNP浓度快速升高,后期呈下降趋势。     

基于桡动脉脉搏波血流动力学检测的心输出量计算修正

目的心输出量是评估心血管功能的重要参数.长期以来,心输出量作为常规的心血管血流参数已被临床医生、药剂师和生理学家所接受.北京工业大学罗志昌等人通过多年研究,获得了心输出量的临床实用公式,但此公式中的一些近似是以正常健康人的生理条件为基准,在长期的实验中,发现由此得出的心输出量在一些情况下失真,因此有必要对这种失真进行修正.方法通过大量临床实验,用线性回归的方法,通过修正系数,对心输出量计算公式进行修正.结果修正系数与脉搏波特征参数K、年龄、血压和心率有关,修正后的公式计算的心输出量较为接近实际值.结论在没有经过心外科手术的无心瓣膜缺损、主动脉瘤、心衰、心率不齐等疾病的患者,以及健康的孕妇、运动员和普通的健康人中,通过脉搏波特征参数K、年龄、血压和心率计算心输出量是比较可靠的.     

汉族与回族人群外周血管阻力及其相关因素的比较

 目的 对宁夏回族自治区银川市汉族与回族人群外周血管阻力的差异及其相关影响因素探讨和分析。方法 采用美国Bioz.com数字化无创血液动力学监护仪,检测了2 795名汉族和1 886名回族人群体循环血管阻力（SVR）、体循环血管阻力指数（SVRI）、收缩压（SBP）、舒张压（DBP）、体质量指数（BMI）、心输出量（CO）、心指数（CI）、心率（HR）、平均动脉压（MAP）,同时进行相关因素的分析。结果 1﹚回族16～18岁和30～39岁男性SVR分别显著高于相应年龄的汉族男性（P<0.01,P<0.05）。2）回族16～18岁男性SVRI显著高于相应年龄的汉族男性（P<0.01）。多元线性回归显示：对回、汉两民族之间SVR差异影响的强弱依次为MAP、CI、HR、SBP及DBP;对SVRI影响的贡献大小指标顺序与SVR一致。结论 回族SVR/SVRI高于汉族可能与遗传及生活方式有关。     

血流动力学参数自适应检测分析系统

本文介绍一种具有自编程功能的血流动力学参数计算机自动监测分析系统 ,本系统在软件设计中引入了自我编程的概念 ,并提供了多个自定义函数 ,允许用户根据信号的具体特征和编写参数分析表达式 ,使血流动力学参数监测和分析更具灵活性和准确性 ,同时具有实时分析功能 ,较好地解决了因实验动物种属差异和在麻醉、病理状态下信号异常变化造成的自动分析系统适应性差的难题 ,是一理想的心功能血流动力学参数实时检测分析系统。     

体质指数对超重与肥胖青少年血压的影响

目的探讨体质指数对超重与肥胖青少年高血压的影响。方法测量郴州市6所学校部分12～15岁青少年体重、身高、血压。结果 2566名在校学生血压偏高率为20.7%,其中血压偏高在非超重组、超重组和肥胖组检出率分别为19.15%、34.55%和39.29%,非超重组、超重组和肥胖组儿童血压偏高检出率组间差异有统计学意义（P〈0.05）。结论青少年血压偏高检出率随体质指数增加而明显增高。     

A continuous cardiac output computer based on thermodilution principles

A totally self-contained instrument for the measurement of cardiac output is described. The microcomputer controlled instrument is based upon the principles of thermodilution and is capable of making cardiac output determinations on a minute by minute basis. A bolus of heat is delivered to the blood via a resistive heating element wound on the surface of a conventional thermodilution catheter, and the resulting transient pulmonary artery blood temperature increase is monitored with the thermistor located near the tip of the catheter. The performance of the instrument was tested in a mock circulatory loop and in dogs for periods of up to 13 hours. The accuracy and reproducibility of flow determinations made with the system compare favorably with those made with a conventional cardiac output monitor. This study demonstrates the feasibility of a stand-alone cardiac output computer that can provide virtually continuous measurements of blood flow without the intervention of a technician.     

Investigation of a continuous heating/cooling technique for cardiac output measurement

Cardiac output is frequently measured to assess patient hemodynamic status in the operating room and intensive care unit. Current research for measuring cardiac output includes continuous sinusoidal heating and synchronous detection of thermal signals. This technique is limited by maximum heating element temperatures and background thermal noise. A continuous heating and cooling technique was investigated in vitro to determine if greater thermal signal magnitudes could be obtained. A fast responding thermistor was employed to measure consecutive ejected temperature plateaus in the thermal signal. A flow bath and mechanical ventricle were used to simulate the cardiovascular system. A thermoelectric module was used to apply heating and cooling energy to the flow stream. Trials encompassing a range of input power, input frequency, and flow rate were conducted. By alternating heating and cooling, thermal signal magnitude can be increased when compared to continuous heating alone. However, the increase was not sufficient to allow for recording in all patients over the expected normal range of cardiac output. Consecutive ejected temperature plateaus were also measured on the thermal signal and ejection fraction calculations were made.     

Effect of propranolol on some mechanisms regulating cardiac output

In acute experiments on anesthetized cats propranolol reduced the venous return to the heart while increasing the capacity of the systemic venous circulation. Myocardial -adrenoreceptor blockade is not the only cause, of this effect.Division of Experimental Physiology and Pharmacology, Central Research Laboratory, Academician I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 9, pp. 307–309, September, 1979.     

50例贲门癌患者血细胞参数临床价值的分析

目的 检测贲门癌患者血细胞参数，评价其临床意义。方法 利用SYSMEX-XE-2100血细胞分析仪监测50例贲门癌患者静脉血，其结果与正常对照组对比分析。结果 贲门癌组WBC、RBC、HGB、HCT、PLT、MPV降低(P＜0．01)；GR、MCV、RDW、MCH增高(P＜0．01)；LY、MCHC在正常范围内(P＞0．05)。结论 贲门癌患者存在恶性贫血倾向及慢性DIC发展过程。因此，监测其外周血细胞变化对了解该贫血及血栓前状态的发生和发展趋势具有一定临床价值。     

Estimation of the cardiac output in the presence of a pathological arteriovenous shunt

The aim of the investigation was to develop a quantitative method of determining the cardiac output by the thermodilution principle in patients with congenital heart diseases accompanied by a pathological arteriovenous shunt. A method of graphic analysis of the curves based on standard ratios between heights of the descending part is suggested. Values of left-right shunts similar to results obtained by the Fick method can be obtained by the method now suggested.M. F. Vladimirskii Moscow Regional Clinical Research Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 239–240, February, 1980.     

Noninvasive measurement of cardiac performance in recovery from exercise in heart failure patients

OBJECTIVE:

To examine the association between cardiac performance during recovery and the severity of heart failure, as determined by clinical and cardiopulmonary exercise test responses.

METHODS:

As part of a retrospective cohort study, 46 heart failure patients and 13 normal subjects underwent cardiopulmonary exercise testing while cardiac output was measured using a noninvasive device. Cardiac output in recovery was expressed as the slope of a single exponential relationship between cardiac output and time; the recovery-time constant was assessed in relation to indices of cardiac function, along with clinical, functional, and cardiopulmonary exercise responses.

RESULTS:

The recovery time constant was delayed in patients with heart failure compared with normal subjects (296.7±238 vs. 110.1±27 seconds, p <0.01), and the slope of the decline of cardiac output in recovery was steeper in normal subjects compared with heart failure patients (p<0.001). The slope of the decline in cardiac output recovery was inversely related to peak VO₂ (r = -0.72, p<0.001) and directly related to the VE/VCO₂ slope (r = 0.57, p<0.001). Heart failure patients with abnormal recovery time constants had lower peak VO₂, lower VO₂ at the ventilatory threshold, lower peak cardiac output, and a heightened VE/VCO₂ slope during exercise.

CONCLUSIONS:

Impaired cardiac output recovery kinetics can identify heart failure patients with more severe disease, lower exercise capacity, and inefficient ventilation. Estimating cardiac output in recovery from exercise may provide added insight into the cardiovascular status of patients with heart failure.     

心率对每搏输出量和心输出量影响的讨论

本文试图从理论模型上分析心率对每搏输出量和心输出量的影响情况，结果表明，虽然每搏输出量随心率的增加而减小，但心率低于90次/分的情况下，每搏输出量随心率的变化很小，相对变化量不大于3%，而心输出量与心率之间存在函数关系，心率较低的情况下，心输出量随心率的增大而增大，心输出量达到极大值后，心输出量随心率的增大而下降。