Zilcher H
Acta Med Austriaca Suppl. 1979;15:1-34.
Two types of vasodilators are used for treatment of acute myocardial infarction: Nitrates on the one hand with predominant venodilation and agents like Phentolamie and Nitroprusside on the other hand with venodilation as well as arteriolar vasodilation. Different opinions exist with respect to indication of these vasodilators. They are used for reduction of arterial blood pressure, for reduction of left ventricular filling pressure and for increase of cardiac output. A marked decrease in ejection fraction is the hemodynamic basis of application of vasodilators in the latter indication. By reduction of peripheral vascular resistance emptying of the left ventricle in these patients is enhanced.) As a working hypothesis in clinical situation elevated filling pressure indicates a decreased ejection fraction. The first part of this investigation deals with relation of left ventricular and diastolic pressure to ejection fraction. A good correlation between these two parameters was found in 717 patients with coronary artery disease. However variability was so wide that regression from enddiastolic pressure to ejection fraction in the individual seemed impossible. In 26.6% of patients with ejection fraction over 0.6%, filling pressure was 20 mm Hg or more. On the other hand, in 34.7% of patients with ejection fraction below 0.3% filling pressure was 20 mm Hg or less. As a consequence of practical value, reduced ejection fraction has to be assumed, if a patient presents elevated filling pressure and reduced cardiac output. In the second part, the hemodynamic effects of Phentolamine in 12 patients with acute myocardial infarction and elevated filling pressure (PCV resp. PADP greater than 18 mm Hg) are described. Maximal effects on hemodynamic variables were: reduction of peripheral vascular resistance by 31.4%, of left ventricular filling pressure by 16.2%, and of mean arterial pressure by 17.0%. Cardiac output increased by 25.8% and heart rate rose by 14.8%. At optimal efficacy, stroke volume increased by 23.7%. Further increase of infusion rate with concomitant fall of peripheral vascular resistance resulted in decrease of stroke volume and tachycardia. Most serious side effects consisted in sudden fall of blood pressure. Therefore intraarterial monitoring of blood pressure is demanded. The third part deals with hemodynamic effects of nitrates (Isosorbiddinitrate 10 mg p.o.) in patients with acute myocardial infarction and elevated filling pressure. One hour after application peripheral vascular resistance decrease by 16.5%, filling pressure by 20.8%, and mean arterial pressure by 9.0%. Cardiac output stroke volume and heart rate did not change significantly. No side effects were observed with Isosorbiddinitrate although two cases of nitrate syncope occurred with Nitroglycerin, resulting in bradycardia and hypotension. Indications for vasodilator therapy therefore has to be handled as follows: Nitrates should be given to patients with elevated filling pressure and normal cardiac output...
一方面是硝酸盐类,主要起静脉扩张作用;另一方面是酚妥拉明和硝普钠等药物,既有静脉扩张作用,也有小动脉扩张作用。关于这些血管扩张剂的适应证存在不同观点。它们用于降低动脉血压、降低左心室充盈压以及增加心输出量。射血分数显著降低是在后者适应证中应用血管扩张剂的血流动力学基础。通过降低外周血管阻力,可增强这些患者左心室的排空。)作为临床情况下的一个工作假设,充盈压升高表明射血分数降低。本研究的第一部分探讨左心室舒张压与射血分数的关系。在717例冠心病患者中发现这两个参数之间有良好的相关性。然而,变异性非常大,以至于似乎不可能根据个体舒张末期压力来推断射血分数。在射血分数超过0.6%的患者中,26.6%的患者充盈压为20毫米汞柱或更高。另一方面,在射血分数低于0.3%的患者中,34.7%的患者充盈压为20毫米汞柱或更低。由于其实际价值,如果患者出现充盈压升高和心输出量降低,就必须假定射血分数降低。在第二部分中,描述了酚妥拉明对12例急性心肌梗死且充盈压升高(肺毛细血管楔压或肺动脉舒张压大于18毫米汞柱)患者的血流动力学影响。对血流动力学变量的最大影响为:外周血管阻力降低31.4%,左心室充盈压降低16.2%,平均动脉压降低17.0%。心输出量增加25.8%,心率上升14.8%。在最佳疗效时,每搏量增加23.7%。随着外周血管阻力下降,输注速率进一步增加导致每搏量减少和心动过速。最严重的副作用是血压突然下降。因此需要进行动脉内血压监测。第三部分探讨硝酸盐类(口服硝酸异山梨酯10毫克)对急性心肌梗死且充盈压升高患者的血流动力学影响。用药1小时后,外周血管阻力降低16.5%,充盈压降低20.8%,平均动脉压降低9.0%。心输出量、每搏量和心率无明显变化。硝酸异山梨酯未观察到副作用,尽管硝酸甘油有2例发生硝酸盐晕厥,导致心动过缓和低血压。因此,血管扩张剂治疗的适应证应如下处理:对于充盈压升高且心输出量正常的患者应给予硝酸盐类……