急性心肌梗死患者早期血浆脑钠肽水平与左室重构及预后关系的评估

目的:探讨急性心肌梗死(AMI)早期脑钠肽(BNP)水平与左室重构及预后的关系.方法:用放射免疫法测定AMI患者早期血浆BNP水平;用超声心动图检查测量左室收缩末容积(ESV)、左室舒张末容积(EDV)、射血分数(EF)并通过计算得左室质量(LVM).并根据左心室容积指标分组,左心室容积增加率＞20%为左心室重构组,否则为非重构组,比较两组血浆BNP水平.结果:重构组恢复期左心室舒张末期及收缩末期容积指数均高于非重构组(P＜0.01),亦高于急性期左心室容积(P＜0.01).重构组早期血浆BNP浓度明显高于非重构组(P＜0.01),恢复期也较非重构组高(P＜0.01).重构组早期BNP浓度与恢复期左心室容积及容积变化量之间呈正相关.结论:AMI早期BNP升高与急性期左室重构密切相关,血浆BNP浓度可以作为溶栓治疗再通的观察指标及预后判断依据.     

Echocardiographic calculation of left ventricle ejection volume. 1) Preliminary note: comparison of diverse formula

Four different formulae to calculate left ventricular ejection volume were examined in the present study. Formulae show a different degree of reliability and, however, their use prove to be limited if heart rate factor is not considered. These results emphasized the great importance of determining left ventricular ejection volume in terms of cardiac output.     

Circumferential analysis of digitalized gamma angiocardiography by assessment of regional left ventricular contraction

After acquisition of a digital equilibrium gamma-angiocardiographie, circumferential analysis of end-diastolic and end-systolic frames gives 120 points diastolic and systolic curves. Their difference represents systolic volume and leads to regional left ventricular ejection fraction assessment at the considered radius level. The circumferential analysis evolute gives the regional left ventricular ejection fraction representative curves which allows especially differential diagnosis between left ventricular akinesia and dyskinesia.     

Influence of left bundle branch block on left ventricular volumes, ejection fraction and regional wall motion

Background. Left ventricular volumes, ejection fraction and regional wall motion are cardiac parameters which provide valuable information for patient management in a large variety of cardiac conditions. Differences in regional wall motion are of relevance in the field of cardiac resynchronisation therapy. We quantified three-dimensional echocardiographic measurements of left ventricular volumes, ejection and regional wall motion (e.g. expressed as systolic dyssynchrony index (SDI)) in two patient cohorts: patients with normal conduction and patients with complete left bundle branch block. Methods. Thirty-five patients scheduled for routine cardiac examination underwent three-dimensional echocardiography: 23 patients with normal conduction and 12 patients with a complete left bundle branch block. Full-volume datasets were analysed and end-systolic volume (ESV), end-diastolic volume (EDV) and ejection fraction (EF) were obtained. SDI was derived from the standard deviation of the measured times to reach minimal regional volume for each of the 16 segments of the left ventricle. Results. A significant difference was observed in left ventricular volumes, ejection fraction and SDI between the two groups. Patients with complete left bundle branch block showed higher EDV (p=0.025) and ESV (p<0.01) and a lower EF (p<0.01) than patients with normal conduction. SDI is significantly higher in patients with complete left bundle branch block (p=0.004) expressing a higher amount of ventricular dyssynchrony. Intraobserver variability showed excellent correlation coefficients: r=0.99 for EDV, ESV and SDI and r=0.98 for EF. Conclusion. Three-dimensional echocardiography is a feasible and reproducible method for the quantification of left ventricular volumes, left ventricular ejection fraction and regional wall motion. Differences can be assessed between normal patients and patients with left bundle branch block. (Neth Heart J 2007;15:89-94.)     

Interrelationships between left ventricular volume and output during exercise in healthy subjects.

To better characterize the relationship between left ventricular volume response and improved ventricular ejection and output during supine exercise in normal subjects, 36 healthy asymptomatic volunteers (age 39 +/- 17 yr) were studied with radionuclide ventriculography during recumbent bicycle ergometry. Relative changes in left ventricular end-diastolic and end-systolic volume were measured at rest and during exercise by a modification of the radionuclide counts-based method that accounted for variability in stress blood pool counts. A biphasic response was noted in left ventricular end-diastolic volume with an initial increase in early exercise (8.5 +/- 11% at 200 kpm/min and 11 +/- 12% at 300 kpm/min) followed by a progressive and significant decline at peak exercise (-3.3 +/- 18% at 547 +/- 140 kpm/min; P < 0.05). There was substantial variation in end-diastolic volume response at peak exercise in the group as a whole, which could be more closely related to changes in end-systolic volume (r = 0.84, P < 0.0001) than in heart rate (r = -0.57, P < 0.01) or age (r = 0.36, P < 0.05) of the study subjects. Despite the decline in ventricular filling, systolic function appeared to improve dramatically at peak exercise (change in left ventricular ejection fraction 15.5 +/- 6.4, P < 0.0001). Although not directly related to increasing systolic ejection, end-diastolic volume was directly related to the percent change in stroke volume at peak exercise among the study subjects (r = 0.88, P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular systolic time intervals and plasma noradrenaline concentrations during acute hypovolaemia in newborn infants

Left ventricular systolic time intervals and plasma noradrenaline concentrations were determined in twelve newborn infants during acute moderate hypovolaemia. Rapid withdrawal of 8.5 ml of blood per kg body weight shortened the left ventricular ejection time from 204 to 176 msec (P less than 0.001) and increased the plasma noradrenaline concentration from 3.4 to 4.0 nmol/l (P less than 0.05). Systemic blood pressure was unchanged. It is concluded that even a moderate reduction in blood volume is associated with marked changes in left ventricular dynamics. The shortening of left ventricular ejection time during hypovolaemia probably reflects left ventricular adaptation to decreased volumes and response to increased noradrenaline release.     

急性心肌梗死患者早期血浆脑钠肽水平与左室重构及预后关系的评估

目的：探讨急性心肌梗死（AMI）早期脑钠肽（BNP）水平与左室重构及预后的关系。方法：用放射免疫法测定AMI患者早期血浆BNP水平;用超声心动图检查测量左室收缩末容积（ESV）、左室舒张末容积（EDV）、射血分数（EF）并通过计算得左室质量（LVM）。并根据左心室容积指标分组,左心室容积增加率〉20%为左心室重构组,否则为非重构组,比较两组血浆BNP水平。结果：重构组恢复期左心室舒张末期及收缩末期容积指数均高于非重构组（P〈0.01）,亦高于急性期左心室容积（P〈0.01）。重构组早期血浆BNP浓度明显高于非重构组（P〈0.01）,恢复期也较非重构组高（P〈0.01）。重构组早期BNP浓度与恢复期左心室容积及容积变化量之间呈正相关。结论：AMI早期BNP升高与急性期左室重构密切相关,血浆BNP浓度可以作为溶栓治疗再通的观察指标及预后判断依据。     

Left ventricular function early after aortic valve replacement for aortic regurgitation: Assessment by gated radionuclide ventriculography

This study characterizes left ventricular performance early after aortic valve replacement for severe isolated aortic regurgitation. Gated radionuclide ventriculography studies in 13 patients showed that left ventricular end-diastolic volume was reduced after surgery and that ejection fraction dropped significantly. Despite the fall in ejection fraction, the postoperative cardiac index was significantly greater than the preoperative value. Radionuclide ventriculography is a useful and reliable means of noninvasively assessing left ventricular function soon after aortic valve replacement for aortic regurgitation.     

磁共振成像对扩张型心肌病转基因模型小鼠左右心室对比分析

目的对cTnTR141W扩张型心肌病转基因模型小鼠左、右心室进行对比分析,研究cTnTR141W转基因小鼠作为右心室心肌病的动物模型的可行性。方法利用7.0 T高场强磁共振成像(MRI)技术,定量分析了2、4、6和8月龄对照组及cTnTR141W转基因模型小鼠左、右心室的舒张末容积(EDV)、收缩末容积(ESV)和射血分数(EF)的变化情况,同时对6月龄对照组cTnTR141W转基因模型小鼠心肌组织进行组织学分析。结果转基因阴性对照小鼠相比,cTnTR141W转基因小鼠左、右心室的容积在2月龄时已有增大趋势,而射血分数有减小趋势。右心室射血分数减小出现最早也最显著(P<0.05)。随年龄增加,cTnTR141W转基因小鼠与转基因阴性对照小鼠相比,右心室的结构和功能的病理生理变化与左心室同时趋于严重。该小鼠左、右心室在4月龄后表现典型的扩张型心肌病表型。结论 cTnTR141W转基因模型小鼠左心室和右心室的扩张性心肌病表型同时出现,该小鼠可作为右室性心肌病等右心室功能下降相关疾病研究的动物模型。     

Effects of acute changes in load and inotropic state on the exponential rate of fiber shortening and other indices of myocardial contractility in the anesthetized intact dog

The effects of an acute increase in preload, afterload, and inotropic state on several indices of left ventricular contractility were studied in 20 anesthetized intact dogs. The behaviour of the exponential rate of fiber shortening (ERFS), a newly described index, which is based on the instantaneous fiber length--time relationship through ejection, was compared with other classical ejection and isovolumic indices of left ventricular contractility. Acute volume overload by dextran 40 infusion produced a significant increase in preload as reflected by a 103% (p less than 0.01) increase in left ventricular end-diastolic pressure and a 121% (p less than 0.001) increase in end-diastolic circumferential wall stress. There was also a smaller but significant increase (p less than 0.05) of heart rate (30%) and of peak systolic circumferential wall stress (24%). None of the left ventricular contractility indices showed any significant change. Acute pressure overload, produced mechanically by an aortic balloon, increased the afterload significantly as reflected by a 33% (p less than 0.05) rise of end-systolic circumferential wall stress and a 43% (p less than 0.001) increase in systemic resistance. Stroke volume decreased significantly by 23% (p less than 0.05). All ejection indices, including ERFS, were significantly diminished by 30-37%; all isovolumic indices showed no significant changes. Positive inotropic intervention was induced by dopamine infusion, which caused a significant 28% (p less than 0.05) increase in cardiac output. End-diastolic and end-systolic circumferential wall stress were significantly diminished. All indices of left ventricular contractility increased significantly and ERFS showed the quantitatively greatest change.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of glossopharyngeal insufflation on cardiac function: an echocardiographic study in elite breath-hold divers.

Glossopharyngeal insufflation (GI), a technique used by breath-hold divers to increase lung volume and augment diving depth and duration, is associated with untoward hemodynamic consequences. To study the cardiac effects of GI, we performed transthoracic echocardiography, using the subcostal window, in five elite breath-hold divers at rest and during GI. During GI, heart rate increased in all divers (mean of 53 beats/min to a mean of 100 beats/min), and blood pressure fell dramatically (mean systolic, 112 to 52 mmHg; mean diastolic, 75 mmHg to nondetectable). GI induced a 46% decrease in mean left ventricular end-diastolic area, 70% decrease in left ventricular end-diastolic volume, 49% increase in mean right ventricular end-diastolic area, and 160% increase in mean right ventricular end-diastolic volume. GI also induced biventricular systolic dysfunction; left ventricular ejection fraction decreased from 0.60 to a mean of 0.30 (P = 0.012); right ventricular ejection fraction, from 0.75 to a mean of 0.39 (P < 0.001). Wall motion of both ventricles became significantly abnormal during GI; the most prominent left ventricular abnormalities involved hypokinesis or dyskinesis of the interventricular septum, while right ventricular wall motion abnormalities involved all visible segments. In two divers, the inferior vena cava dilated with the appearance of spontaneous contrast during GI, signaling increased right atrial pressure and central venous stasis. Hypotension during GI is associated with acute biventricular systolic dysfunction. The echocardiographic pattern of right ventricular systolic dysfunction is consistent with acute pressure overload, whereas concurrent left ventricular systolic dysfunction is likely due to ventricular interdependence.     

芪苈强心胶囊联合比索洛尔对老年心力衰竭患者的疗效

目的:研究芪苈强心胶囊联合比索洛尔对老年心力衰竭患者的临床疗效。方法:选择2015年6月~2016年6月在我院进行诊治的老年心力衰竭患者126例,随机分为两组,对照组给予芪苈强心胶囊,观察组在对照组基础上加用比索洛尔。治疗3个月后,比较两组的疗效,以及治疗前后的血压、心率、6 min步行最大距离、脑钠肽水平;采用超声心动图检测两组的左心室舒张末期容积、左心室射血分数、左心室短轴缩短率和左心室收缩末期容积。结果:观察组的有效率为92.06%(58/63),明显高于对照组的73.02%(46/63)(P0.05);治疗后两组血压无明显变化(P0.05),心率和脑钠肽水平明显降低(P0.05),6 min步行最大距离明显增加(P0.05),且观察组明显优于对照组(P0.05);两组的左心室射血分数明显降低(P0.05),左心室舒张末期容积、左心室短轴缩短率和左心室收缩末期容积明显升高(P0.05),且观察组明显优于对照组(P0.05)。结论:芪苈强心胶囊联合比索洛尔能有效改善老年心力衰竭患者的心功能,具有较好的临床疗效。     

Association of serum total bilirubin levels with diastolic dysfunction in heart failure with preserved ejection fraction

Background

Left ventricular diastolic dysfunction is one of the main characteristics of heart failure patients with a preserved left ventricular ejection fraction. As bilirubin is regarded as an important endogenous antioxidant molecule, serum total bilirubin levels were compared between heart failure patients with a preserved left ventricular ejection fraction and normal controls in this study. We recruited 327 heart failure patients with a preserved left ventricular ejection fraction and 200 healthy controls. Patients were divided into 4 subgroups by their comprehensive echocardiographic manifestations, 1-mild, 2-moderate, 3-severe (reversible restrictive), 4-severe (fixed restrictive). Total bilirubin levels were compared using stepwise multiple regressions adjusted for selected factors.

Results

After adjusting for gender, age, smoking, systolic blood pressure, diastolic blood pressure, total cholesterol and triglyceride, serum total bilirubin levels were significantly lower in the heart failure group compared with the control group (P < 0.01). Patients in the subgroup (4-severe) showed significantly (P < 0.05) lower levels of total bilirubin when compared with the subgroup (1-mild).

Conclusions

TB level was negatively correlated with left ventricular diastolic dysfunction in heart failure patients with a preserved left ventricular ejection fraction, which might provide a new insight into the complicated mechanisms of heart failure with a preserved left ventricular ejection fraction.     

Dynamic geometry of the intact left ventricle

Knowledge of left ventricular chamber dynamics is central to our understanding of cardiac physiology. The complicated changes in left ventricular geometry observed in the dog during various phases of the cardiac cycle can be represented as distinct linear relationships between chamber eccentricity and intracavitary volume during diastole and ejection, and probably represent structural properties of the ventricular wall. Chamber geometry of the left ventricle is a major determinant of overall myocardial function. The slope of the radius of curvature (r) to wall thickness (h) relationship is a geometric constant that determines the mural force at any given transmural pressure. Chronic pressure and volume overload produce changes in this geometric relationship as a result of increased mural force resisting ejection. The adaptive mechanism of ventricular hypertrophy in this setting alters the r/h ratio and returns systolic mural force toward normal. Coronary occlusion induces acute changes in regional geometry characterized by holosystolic wall bulging and systolic wall thinning, which shift the r/h relationship upward and to the left. The geometric alteration during ischemia probably increases systolic mural force and could adversely affect myocardial function. Recent studies with patients have shown the r/h ratio to be of value in distinguishing between reversible and irreversible impairment of myocardial performance. Because most myocardial diseases produce major alterations in the structure of the ventricular wall, analysis of dynamic chamber geometry may prove of prognostic value in assessing patients with cardiac disorders.     

心肌梗死患者择期行PCI治疗对左心室重构和收缩功能的影响

目的:研究心肌梗死患者择期行经皮冠状动脉介入(PCI)治疗对左心室重构和收缩功能的影响。方法:选取2009年12月到2014年12月我院收治的心肌梗死择期行PCI治疗的患者60例(研究组),另选同期单纯心绞痛行PCI治疗的患者60例(对照组)。比较治疗前、后两组左心室舒张末期容积(LVEDV)、收缩末期容积(LVESV)、每搏量(SV)、左室射血分数(LVEF)、左室收缩末期压(LVESP)和左心室舒张末压(LVEDP)。结果:治疗后研究组LVEDV、LVESV、SV、LVEF、LVESP和LVEDP均显著优于治疗前,比较差异均具有统计学意义(P0.05),对照组治疗前、后LVEDV、LVESV、SV、LVEF、LVESP和LVEDP比较差异均无统计学意义(P0.05)。结论:心肌梗死患者行PCI治疗具有较好的效果,能显著改善患者的左心室重构和收缩功能。     

Optimal control aspects of left ventricular ejection dynamics

A model of the ejecting left ventricle is developed in which ventricular elastance as a function of time is optimized with respect to a simple performance index selected on an energetic basis. The model correctly predicts a number of well known experimental findings concerning the effects of preload and afterload conditions and varying system parameters on left ventricular pressure and elastance waveforms and on the ejection period. The results characterize ventricular systolic elastance as dependent on both end-diastolic volume and mean aortic pressure.     

急性心力衰竭患者就诊时血压心率及血浆BNP水平与心功能的关系分析

目的:探讨急性心力衰竭(AHF)患者就诊时血压心率及血浆脑钠肽(BNP)水平与心功能的关系。方法:选取2013年4月-2014年12月于本院治疗的AHF患者134例,于就诊时测量患者血压、心率、BNP及心脏超声相关指标,分析血压心率及血浆BNP水平与心功能的关系。结果:就诊时SBP水平与左心室舒张末期直径及每搏输出量呈现正相关性(r=0.134、0.238,均P0.05);心率与每搏输出量、左室缩短率以及射血分数呈现负相关性(r=-0.177,-0.231,-0.197,均P0.05);BNP水平与左心室舒张末直径成正相关性,与左室缩短率以及射血分数呈负相关性(r=0.150、-0.247、-0.271,均P0.05)。结论:血压、心率以及BNP是临床诊断、评估AHF的重要指标。     

Anomalous origin of the left coronary artery: the effects of aortocoronary vein bypass on left ventricular function

The diagnosis, angiographic evaluation and surgical treatment by aortocoronary vein bypass are described in a 3½-year-old girl with anomalous origin of the left coronary artery from the pulmonary artery. The anomaly had resulted in cardiac dilatation, diminished left ventricular contractility, an aneurysm of the left ventricular free wall and mitral regurgitation.At the postoperative cardiac catheterization the graft was demonstrated to be patent, but a significant proportion of the flow to the left coronary artery was derived from anastomotic connections with the right coronary artery. The most striking evidence of improvement was obtained from the left ventricular volume studies which showed that the end systoiic volume had decreased from 85 to 49 ml./m.² with an increase in ejection fraction from 0.39 to 0.62, suggesting enhanced left ventricular contractility after surgery.The patient continues to do well and is free from symptoms.     

Direct cardiac injection of G-CSF mobilized bone-marrow stem-cells improves ventricular function in old myocardial infarction

Autologous transplant of bone marrow stem cells (BMSC), although extremely useful after acute myocardial events, has not been evaluated in patients with old (>one-year-old) myocardial infarction. Our aim was to determine if CD34(+)-enriched peripheral-blood cells, obtained by apheresis, injected directly into the severely damaged myocardium of five patients with old myocardial infarction could restore depressed myocardial function. We found that 28 weeks after revascularization and peri-infarction injection of the enriched CD34(+) peripheral mononuclear cells, ventricular hemodynamic parameters that included left ventricular ejection fraction, left ventricular diastolic volume, ventricular systolic volume and left ventricular diastolic diameter approximated normal values and there was no restenosis; two patients have been followed for >52 weeks and their parameters are within normal values. In conclusion, intramyocardial injection of easily obtained CD34(+) enriched peripheral blood cells represent an encouraging procedure for patients with severely scarred and dysfunctional myocardium.     

Left ventricular volumes and ejection fraction derived from apical two-dimensional echocardiography

Two-dimensional echocardiographic data in orthogonal apical projections were used to calculate left ventricular ejection fraction and volumes in 18 patients, 10 of whom had asynergy. The left ventricular chamber was modeled as a stack of 20 elliptical discs in order to minimize errors associated with assumptions of regular geometry. Calculations were compared to data from biplane angiography and yielded correlation coefficients of 0.91 for ejection fraction and 0.90 for volumes. The technique significantly underestimated volumes; the average ventricular volume was 161 +/- 23 ml from cineangiography and 104 +/- 25 ml from echocardiography (p < 0.001). Since this technique utilizes the most readily obtained echocardiographic views and allows for variations in ventricular architecture, its potential utility in long-term, serial evaluation of cardiac function appears promising.