Hess O M, Nonogi H, Grimm J, Krayenbühl H P
Departement für Innere Medizin, Universitätsspital Zürich.
Schweiz Med Wochenschr. 1988 Apr 9;118(14):502-7.
Using quantitative biplane coronary arteriography, coronary vasomotion of normal and stenotic coronary artery segments was studied at rest and during supine bicycle exercise in 37 patients with coronary artery disease. Normal coronary arteries showed vasodilation during exercise, whereas stenotic arteries exhibited vasoconstriction. The occurrence of coronary stenosis narrowing during exercise can be explained either by a collapse of the free vessel wall due to an increase in coronary blood flow velocity (Venturi mechanism) or by insufficient production of the endothelium-derived vasorelaxing factor (endogenous nitrate). To explore further the nature of exercise-induced vasoconstriction of stenotic coronary arteries, intracoronary nitroglycerin, diltiazem or propranolol was given to a subgroup of patients prior to the exercise test. Administration of intracoronary nitroglycerin or diltiazem prevented exercise-induced vasoconstriction, probably due to the direct vasorelaxing effect of the drug on the smooth vasculature. Intracoronary administration of propranolol also prevented exercise-induced vasoconstriction, either due to a reduction in trans-stenotic pressure gradient (local beta blockade with a decrease in local coronary blood flow or an increase in distal arteriolar tone due to unopposed alpha-constrictor tone) or because of a local anesthetic effect of propranolol with a decrease in calcium influx into the smooth vasculature.
采用定量双平面冠状动脉造影术，对37例冠心病患者静息时及仰卧位自行车运动期间正常和狭窄冠状动脉节段的冠脉血管运动进行了研究。正常冠状动脉在运动时表现为血管扩张，而狭窄动脉则表现为血管收缩。运动期间冠状动脉狭窄程度加重可通过冠状动脉血流速度增加导致的血管壁塌陷（文丘里效应）或内皮源性血管舒张因子（内源性硝酸盐）产生不足来解释。为了进一步探究运动诱发的狭窄冠状动脉血管收缩的本质，在运动试验前对一组患者给予冠状动脉内硝酸甘油、地尔硫䓬或普萘洛尔。冠状动脉内给予硝酸甘油或地尔硫䓬可预防运动诱发的血管收缩，这可能是由于药物对血管平滑肌的直接舒张作用。冠状动脉内给予普萘洛尔也可预防运动诱发的血管收缩，这要么是由于跨狭窄压力梯度降低（局部β受体阻滞导致局部冠状动脉血流减少或由于α受体收缩作用未被拮抗导致远端小动脉张力增加），要么是由于普萘洛尔的局部麻醉作用使钙离子流入血管平滑肌减少。
