Inou T, Lamberth W C, Koyanagi S, Harrison D G, Eastham C L, Marcus M L
Department of Internal Medicine, University of Iowa, College of Medicine, Iowa City.
Am J Physiol. 1987 Nov;253(5 Pt 2):H1148-58. doi: 10.1152/ajpheart.1987.253.5.H1148.
We have shown that there was a 50% increase in infarct size and a threefold increase in the incidence of sudden death following coronary occlusion in dogs with hypertension and left ventricular hypertrophy (LVH). To further investigate this problem, we separated the effects of hypertension from those of LVH by decreasing arterial pressure either by renal anastomosis or intravenous administration of nitroprusside in dogs with chronic renal hypertension and LVH. In 123 conscious dogs, the circumflex coronary artery was acutely occluded. Hemodynamics were monitored, myocardial perfusion was measured with labeled microspheres, the risk area was defined by postmortem angiography, and infarct size was determined pathologically 48 h after occlusion. The incidence of sudden death following acute coronary occlusion decreased dramatically in dogs with LVH if the arterial pressure was decreased with either nitroprusside or renal anastomosis. In addition, if arterial pressure was decreased with nitroprusside or renal anastomosis, infarct size in dogs with LVH was not augmented. In conclusion, normotension induced by renal anastomosis or nitroprusside returned infarct size and the incidence of sudden death in dogs with chronic hypertension and LVH toward control values. Thus it is likely that hypertension, as opposed to LVH, is the critical factor responsible for the increase in infarct size and the high incidence of sudden death observed in dogs with hypertension and LVH following sudden coronary occlusion.
我们已经表明，在患有高血压和左心室肥厚（LVH）的犬类中，冠状动脉闭塞后梗死面积增加了50%，猝死发生率增加了两倍。为了进一步研究这个问题，我们通过肾吻合术或静脉注射硝普钠降低患有慢性肾性高血压和LVH的犬类的动脉血压，从而将高血压的影响与LVH的影响区分开来。在123只清醒的犬类中，急性闭塞左旋冠状动脉。监测血流动力学，用标记微球测量心肌灌注，通过死后血管造影确定危险区域，并在闭塞后48小时通过病理方法确定梗死面积。如果用硝普钠或肾吻合术降低动脉血压，LVH犬类急性冠状动脉闭塞后的猝死发生率会显著降低。此外，如果用硝普钠或肾吻合术降低动脉血压，LVH犬类的梗死面积不会增大。总之，肾吻合术或硝普钠诱导的血压正常化使患有慢性高血压和LVH的犬类的梗死面积和猝死发生率恢复到对照值。因此，与LVH相反，高血压可能是导致患有高血压和LVH的犬类在冠状动脉突然闭塞后梗死面积增加和猝死发生率高的关键因素。
