Kern K B, Lancaster L, Goldman S, Ewy G A
Department of Internal Medicine, University of Arizona College of Medicine, Tucson.
Am Heart J. 1990 Aug;120(2):324-33. doi: 10.1016/0002-8703(90)90076-a.
In subjects without coronary disease, coronary perfusion pressure generated with closed-chest cardiopulmonary resuscitation (CPR) bears a direct relationship to myocardial blood flow. The effect of coronary lesions on this relationship was studied in an experimental porcine model not requiring thoracotomy. Coronary stenoses (a 50% reduction in coronary cross-sectional area) or total coronary occlusions were created by percutaneous, transarterial catheter placement of a Teflon cylinder in the left anterior descending artery of 21 swine (30 to 60 kg). Coronary perfusion pressure, defined as the aortic diastolic pressure minus right atrial diastolic pressure, was correlated with myocardial blood flow measured with nonradioactive, colored microspheres during external chest compression CPR. Complete occlusion of the left anterior coronary artery resulted in essentially no CPR-generated blood flow to the anterior myocardium distal to the site of occlusion. Coronary perfusion pressure showed a positive correlation with myocardial blood flow above the area of occlusion (r = 0.783; p less than 0.01) but did not correlate with myocardial blood flow below the occlusion site (r = 0.239). In the presence of a patent coronary artery stenosis, coronary perfusion pressure correlated with myocardial blood flow both above (r = 0.841; p less than 0.001) and below (r = 0.508; p less than 0.05) the stenosis. During closed-chest CPR producing coronary perfusion pressures between 30 and 60 mm Hg, anterior myocardial blood flow was 109 +/- 16 ml/min/100 gm above a patent stenosis and 66 +/- 13 ml/min/100 gm below the stenosis (p less than 0.005). Over a wide range of coronary perfusion pressures, myocardial blood flow below a coronary lesion was significantly less than that above the lesion. Coronary occlusions and stenoses can substantially affect the amount of CPR-generated coronary perfusion pressure needed to produce distal myocardial blood flow.
在无冠心病的受试者中，闭胸心肺复苏（CPR）产生的冠状动脉灌注压与心肌血流直接相关。在一个无需开胸的实验猪模型中研究了冠状动脉病变对这种关系的影响。通过经皮、经动脉将一个聚四氟乙烯圆柱体置于21头猪（30至60千克）的左前降支动脉中，制造冠状动脉狭窄（冠状动脉横截面积减少50%）或完全冠状动脉闭塞。冠状动脉灌注压定义为主动脉舒张压减去右心房舒张压，在胸外按压CPR期间，其与用非放射性彩色微球测量的心肌血流相关。左前冠状动脉完全闭塞导致在闭塞部位远端的前壁心肌基本没有CPR产生的血流。冠状动脉灌注压与闭塞部位上方的心肌血流呈正相关（r = 0.783；p < 0.01），但与闭塞部位下方的心肌血流无相关性（r = 0.239）。在存在冠状动脉狭窄的情况下，冠状动脉灌注压与狭窄上方（r = 0.841；p < 0.001）和下方（r = 0.508；p < 0.05）的心肌血流均相关。在产生30至60毫米汞柱冠状动脉灌注压的闭胸CPR期间，狭窄上方的前壁心肌血流为109±16毫升/分钟/100克，狭窄下方为66±13毫升/分钟/100克（p < 0.005）。在很宽的冠状动脉灌注压范围内，冠状动脉病变下方的心肌血流明显低于病变上方的心肌血流。冠状动脉闭塞和狭窄可显著影响产生远端心肌血流所需的CPR产生的冠状动脉灌注压的量。
