Miwa K, Fujita M, Ejiri M, Sasayama S
Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
Cardiology. 1992;81(4-5):221-32. doi: 10.1159/000175808.
In order to evaluate the effects of intracoronary acetylcholine on coronary resistance vessels, oxygen saturation in coronary sinus blood was continuously measured to compare its dynamic changes during intracoronary injection of acetylcholine in both patients with variant angina and control subjects. Group 1 consisted of 6 patients without coronary artery disease. Group 2 consisted of 10 patients with variant angina and spasm in the left anterior descending coronary artery. A fiberoptic reflection oximetry system was used for the continuous measurement of coronary sinus venous oxygen saturation. Acetylcholine (20 micrograms) was injected directly into the left coronary artery over 30 s. In the group 1 patients, coronary sinus venous oxygen saturation was increased from 39 +/- 2% (mean +/- SEM) to 54 +/- 3% at 30 s, continuously climbed to 70 +/- 3% at 60 s and then gradually decreased to 53 +/- 5% at 120 s after the initiation of intracoronary injection of acetylcholine. In contrast, in the group 2 patients, coronary sinus venous oxygen saturation was transiently increased from 39 +/- 2% to 56 +/- 4% at 30 s, reversed, decreased to 52 +/- 4% at 60 s and then rapidly decreased to 36 +/- 3% at 120 s with the onset of chest pain associated with electrocardiographic ischemic changes. Coronary arteriography during attacks demonstrated a total or subtotal occlusion of the left anterior descending coronary artery due to severe spasm in all of the 10 patients. The extent of increases in coronary sinus venous oxygen saturation at 30 s after acetylcholine injection was not significantly different between the two groups (group 1: 15 +/- 4%, group 2: 17 +/- 3%). Heart rate, blood pressure and rate-pressure product were essentially unchanged at 30 s after intracoronary injection of acetylcholine in both groups. These data suggest that in control adult humans, coronary blood flow was increased through dilatation of resistance vessels by acetylcholine, while in patients with variant angina, coronary blood flow was transiently increased by dilatation of resistance vessels, after which it was suddenly decreased by spasm of an epicardial artery induced by this agent. Relaxant responses to acetylcholine of coronary resistance vessels appear to be preserved well in patients with variant angina.
为了评估冠状动脉内注射乙酰胆碱对冠状动脉阻力血管的影响，连续测量冠状窦血氧饱和度，以比较变异型心绞痛患者和对照组在冠状动脉内注射乙酰胆碱期间其动态变化。第一组由6例无冠状动脉疾病的患者组成。第二组由10例左前降支冠状动脉变异型心绞痛伴痉挛的患者组成。采用光纤反射血氧饱和度测定系统连续测量冠状窦静脉血氧饱和度。在30秒内将乙酰胆碱（20微克）直接注入左冠状动脉。在第一组患者中，冠状动脉内注射乙酰胆碱后30秒，冠状窦静脉血氧饱和度从39±2%（平均值±标准误）升至54±3%，60秒时持续升至70±3%，然后在120秒时逐渐降至53±5%。相比之下，在第二组患者中，冠状窦静脉血氧饱和度在30秒时从39±2%短暂升至56±4%，随后逆转，60秒时降至52±4%，然后在120秒时随着与心电图缺血改变相关的胸痛发作迅速降至3±3%。发作期间的冠状动脉造影显示，所有10例患者均因严重痉挛导致左前降支冠状动脉完全或几乎完全闭塞。两组在乙酰胆碱注射后30秒时冠状窦静脉血氧饱和度的升高幅度无显著差异（第一组：15±4%，第二组：17±3%）。两组在冠状动脉内注射乙酰胆碱后30秒时心率、血压和心率-血压乘积基本未变。这些数据表明，在正常成年人中，乙酰胆碱通过扩张阻力血管增加冠状动脉血流量，而在变异型心绞痛患者中，阻力血管扩张使冠状动脉血流量短暂增加，随后由于该药物诱发的心外膜动脉痉挛而突然减少。变异型心绞痛患者冠状动脉阻力血管对乙酰胆碱的舒张反应似乎保存良好。
