Smith H J, Singh B N, Norris R M, Nisbet H D, John M B, Hurley P J
Aust N Z J Med. 1977 Apr;7(2):114-21. doi: 10.1111/j.1445-5994.1977.tb04676.x.
The effects of verapamil on epicardial ST segment elevation, regional myocardial metabolism and collateral blood flow were studied in open-chest anesthetized dogs following left anterior descending coronary artery occlusion. Collateral blood flow was measured by radioactive microspheres (15 +/- 5 micron diameter) and regional metabolism was studied by measuring lactate concentration in venous blood draining the infarcting myocardium. Verapamil (0-2 mg/kg intravenously) produced a significant reduction (50-60%) in the epicardial ST elevation when it was given before coronary occlusion; when administered 15 minutes after coronary occlusion and infusion continued for two hours, it minimized (30-40%) ST segment elevation, and prevented the fall in cardiac index and rise in systemic resistance found in the untreated animals in which the ST segment remained persistently elevated. Changes in epicardial ST segment occurred without alterations in the QRS duration. Verapamil had no effect on either the total collateral blood flow or the relative distribution of flow to the endocardial and epicardial halves of the ischemic ventricular myocardium. No significant differences were found between the levels of lactate in blood sampled from small epicardial veins at the center of the infarct when the control animals were compared with those treated with verapamil.
在开胸麻醉犬左冠状动脉前降支闭塞后，研究了维拉帕米对心外膜ST段抬高、局部心肌代谢及侧支血流的影响。采用放射性微球（直径15±5微米）测量侧支血流，通过测定梗死心肌引流静脉血中的乳酸浓度研究局部代谢。冠状动脉闭塞前静脉注射维拉帕米（0 - 2毫克/千克）可使心外膜ST段抬高显著降低（50 - 60%）；冠状动脉闭塞15分钟后给药并持续输注两小时，可使ST段抬高最小化（30 - 40%），并防止未治疗动物出现的心脏指数下降和全身阻力升高，这些未治疗动物的ST段持续抬高。心外膜ST段变化时QRS波时限无改变。维拉帕米对总侧支血流或缺血心室心肌心内膜和心外膜两半部分的血流相对分布均无影响。比较对照动物与维拉帕米治疗动物时，梗死中心小的心外膜静脉采集的血样中乳酸水平无显著差异。
