Granato J E, Watson D D, Belardinelli L, Cannon J M, Beller G A
Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
J Am Coll Cardiol. 1990 Dec;16(7):1760-70. doi: 10.1016/0735-1097(90)90331-i.
Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg (p less than 0.05) and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg (p less than 0.05) after intravenous administration of dipyridamole (0.25 mg/kg body weight). In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline (5 mg/kg) reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects (coronary steal) and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal.
进行实验以表征在存在严重冠状动脉狭窄的情况下，静脉注射双嘧达莫和氨茶碱对铊 - 201转运动力学、局部心肌血流和全身血流动力学的相互作用。在12只患有严重左前降支冠状动脉狭窄的犬中，静脉注射双嘧达莫（0.25mg/kg体重）后，动脉压从平均值（±标准误）107±6降至94±3mmHg（p<0.05），左前降支远端动脉压从70±7降至55±4mmHg（p<0.05）。在左前降支灌注区，心内膜 / 心外膜血流比值从0.70降至0.36且固有铊洗脱率显著延长。静脉注射氨茶碱（5mg/kg）可逆转双嘧达莫诱导的全身低血压和透壁性冠状动脉窃血，并使铊洗脱率恢复至基线值。在另外6只犬中，单独使用氨茶碱未导致全身和冠状动脉血流动力学或局部心肌血流发生改变。正如预期的那样，氨茶碱预处理可预防双嘧达莫诱导的血管扩张和冠状动脉窃血。这些数据表明，在部分冠状动脉狭窄的犬模型中，静脉注射双嘧达莫导致的全身低血压、不良的局部血流效应（冠状动脉窃血）和延长的铊 - 201洗脱可通过静脉注射氨茶碱迅速逆转。单独使用氨茶碱对血流动力学和冠状动脉血流无显著影响。本研究进一步深入了解了双嘧达莫诱导的血管扩张导致的铊动力学改变，并表明在接受静脉注射双嘧达莫进行临床成像研究的患者中，氨茶碱迅速逆转缺血症状和体征可能反映了透壁性冠状动脉窃血的逆转。
