Express evaluation of the contractile state of the myocardium after heart operations

By means of the method of long-term catheterization of the cardiac chambers, the authors studied the dynamics of changes in the shape of the intraventricular pressure curves after correction of congenital and acquired heart diseases. Analysis revealed three main types of pressure curves. With the development of myocardial insufficiency under conditions of normal pressure, pressure curves characteristic of hypertension of pulmonary circulation were recorded in the right ventricle. The absence of abnormalities in pulmonary circulation made it possible to demonstrate a direct dependence of the shape of the curves on the contractile condition of the myocardium, which is valuable in the rapid diagnosis of myocardial insufficiency.     

Activated protein C and inflammation in human myocardium after heart surgery

To assess possible interactions between inflammation and activation of the anticoagulant protein C system during post-ischemic reperfusion protein C, APC, neutrophil L-selectin expression and myocardial myeloperoxidase activity (MPO) were measured in 19 patients undergoing cardiopulmonary bypass. After reperfusion for 10 min, APC to protein C ratio (APC/PC) increased from pre-reperfusion value 1.43 +/- 0.12 (mean +/- SEM) to 2.25 +/- 0.29, p = 0.015. Negative correlations were observed between APC/PC and MPO activity (Spearman r -0.64, p = 0.007) and APC/PC and neutrophil L-selectin expression (r = -0.7, p = 0.007, demonstrating that post-ishemic protein C activation was associated with decreased neutrophil tissue sequestration. Thus, physiological protein C activation may be involved in regulation of the inflammatory injury during reperfusion of human ischemic coronary circulation.     

Contractile function of the myocardium in patients with ischemic heart disease after aortocoronary bypass

Fifty patients with coronary heart disease underwent repeated coronary ventriculography in different periods after aortocoronary bypass. The myocardial contractility in the patients after direct myocardial revascularization was comparatively analyzed in relation to the function of imposed aortocoronary anastomoses. Myocardial segmental contractility considerably improved in 23 patients after aortocoronary bypass who had functioning shunts, the integral function being satisfactory within the whole follow-up, whereas left ventricular myocardial function progressively diminished in 27 patients with closed anastomoses. Progressive coronary bed atherosclerosis was found to have a noticeable effect on myocardial contractility.     

Viability of Q-wave infarcted myocardium with restored positive and persistent negative T waves after optimal revascularization compared with dobutamine stress echocardiography

To clarify the clinical difference in viability of myocardium with negative and positive T waves in Q-wave anterior or anteroseptal myocardial infarction, we performed low-dose dobutamine stress echocardiography in 17 patients with negative T waves and in 13 patients with positive T waves with optimal revascularization of infarct-related arteries in the chronic phase of infarction. At baseline the wall motion score (WMS) of the negative and positive T groups was 25.8 +/- 3.0 and 22.3 +/- 2.2 points (p <0.05), respectively. At peak stress WMS in each group was 27.2 +/- 4.2 and 19.8 +/- 2.4 points (p <0.0001), respectively. With dobutamine stress WMS in the positive T group was more decreased than that of the negative T group (p <0.0001). We conclude that the restored positive T waves in Q-wave myocardial infarction indicate a significantly greater amount of viable myocardium than the negative T waves, showing better regional wall motion improvement with low-dose dobutamine stress.     

Field emission scanning electron microscopic study on the noninfarcted myocardium after myocardial infarction

Intracellular membranous ultrastructural changes in the noninfarcted myocardium of the left ventricle were studied by examining experimental myocardial infarction in rats with a field emission scanning electron microscope. The left coronary artery was ligated at its origin for 7 days. The resulting infarcts comprised approximately 40% of the total area of the left ventricles. In a light microscopic study, the transverse diameter of myocytes had increased to 17.1 +/- 2.9 microns in the noninfarcted myocardium, compared to 14.1 +/- 3.1 microns in the myocardium of sham-operated rats (p less than 0.01). For the scanning electron microscopic study, the specimens were processed according to the Osmium-DMSO-Osmium method. Marked morphological changes of intracellular membranous structures were found in the noninfarcted myocardium, especially in the lacelike network of sarcoplasmic reticulum which occasionally formed large flattened cisternae, and in the marked proliferation of surface caveolae. It is speculated that these early ultrastructural changes in the noninfarcted myocardium reflect an adaptation of microorganellae in the failing hearts of the rats.     

Right ventricular myocardium derives from the anterior heart field

The mammalian heart develops from a primary heart tube, which is formed by fusion of bilateral cardiac territories in which myocardial and endothelial cells have already begun to differentiate from splanchnic mesoderm. A population of myocardial precursors has been identified in pharyngeal mesoderm, anterior to the early heart tube. Cell labeling studies have indicated that this novel territory, called the anterior heart field (AHF), gives rise to the myocardial wall of the outflow tract. We now report that not only the myocardium of the outflow tract but also myocardial cells of the embryonic right ventricle are derived from this source. Explants of pharyngeal mesoderm or of the early heart tube were cultured from transgenic mice in which transgene expression marks different regions of the heart. Pharyngeal mesoderm from 5 to 7 somite embryos gives rise to cardiomyocytes with right ventricular and outflow tract identities, whereas the heart tube as this stage has an essentially left ventricular identity. DiI labeling confirms that the early heart tube is destined to contribute to the embryonic left ventricle and indicates that right ventricular myocardium is added from extracardiac mesoderm. Retrospective clonal analysis of the heart at embryonic day (E) 10.5 reveals the existence of a clonal boundary in the interventricular region, which appears during ventricular septation, underlining different origins of the two ventricular compartments. This study demonstrates the differences in the embryological origin of right and left ventricular myocardium, which has important implications for congenital heart disease.     

Changes in the contractility of the myocardium in its various conditions in patients with congenital heart defects after surgery

Intracardiac central hemodynamic parameters were studied and myocardial functional states were assessed in 46 patients with congenital heart disease, 20 of them had stenosed pulmonary artery; 26, presented with secondary atrial septal defect complicated with bacterial endocarditis. The mechanisms responsible for myocardial adaptation after defect correction are discussed. Attention is given to inadequacy of the performance of the heterometric mechanism of regulation due to altered elasticoviscous properties of the cardiac muscle. Plotting the functional curves enables one to gain an insight into the functional states of the myocardium.     

甲状腺激素治疗扩张型心肌病心力衰竭的初步研究

目的 :观察扩张型心肌病 (DCM)心力衰竭患者甲状腺激素 (TH)的异常代谢 ,评估 TH治疗该病的疗效。方法 :19例 DCM心力衰竭患者随机分为观察组和对照组 ,观察组在对照组常规抗心力衰竭治疗基础上加服小剂量左旋甲状腺素 (L- T4) ,疗程 4周 ,治疗前后测血清 TH水平 ,以超声心动图、Holter及 X线胸片观察心脏各参数变化。结果 :患者血清 FT3、FT4明显降低 ,经 L- T4治疗后血清 FT3、FT4升高 ,左室内径缩小 ,室壁增厚 ,左室收缩、舒张功能显著提高。结论 :DCM心力衰竭患者存在低 TH状态 ,经 L- T4补充治疗后 ,心功能改善 ,临床好转。     

大鼠离体心脏急性冬眠心肌模型的建立

利用悬浮人类红血球的改良K-H液灌流大鼠离体等容收缩心脏,建立了急性冬眠心肌模型,缺血期间冠状动脉流量下降80%.结果表明,缺血30分钟时,左室内收缩峰压、dp/dt max、—dp/dt max分别降到对照组的44%、33%和26%(P均<0.05),缺血期间保持恒定,再灌注30分钟完全恢复.缺血90分钟,心肌ATP、磷酸肌酸(Crp)及糖原含量明显降低(P均相似文献   

Clinical study of the stunned myocardium.

Clinical features of 37 cases of stunned myocardium were studied. Mean duration of asynergy was 22.6 +/- 15.7 days. In all 11 cases of unstable angina without any significant serum creatine kinase leakage, the duration of asynergy was within 14 days. Related coronary lesions were reperfused (spontaneously or by interventional therapy) to TIMI grade II or higher. Transient Q waves were observed in 39% of all cases. Negative T waves tended to be prolonged, and persisted after disappearance of asynergy in 74% of all cases. 201Tl uptake in the stunned area varied widely between individual cases (ranging from "absent" to "normal"), although it became normal in all cases in the chronic stage. Mal-distribution of 99mTc-pyrophosphate (PYP) to the endocardial side of the stunned area was observed in 33%. In 186 cases of acute coronary syndrome, we studied whether or not reversibility of ischemia-disturbed myocardium could be predicted by simultaneous dual isotope SPECT, and found that 201Tl-uptake in the chronic stage significantly improved in the region showing absence of 99mTc-PYP accumulation or maldistribution of 99mTc-PYP to the endocardial side, while reversibility of the region showing transmural 99mTc-PYP accumulation and a dought pattern was poor. Ischemia-associated myocardial damage recovered to various degrees, and dual isotope SPECT was useful in evaluating the reversibility of such damage already at the acute stage.