Dellsperger K C, Clothier J L, Koyanagi S, Inou T, Marcus M L
Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City 52242.
J Cardiovasc Pharmacol. 1991;17 Suppl 2:S40-5. doi: 10.1097/00005344-199117002-00010.
Chronic arterial hypertension (HT) and left ventricular hypertrophy (LVH) increase the morbidity and mortality of acute myocardial infarction in patients. In this article, we discuss earlier studies from Koyanagi et al. in our laboratory that showed that when animals with chronic HT and LVH (HT-LVH) were subjected to acute coronary artery occlusion (CAO), there was a 3.5-fold increase in mortality and a 35% increase in infarct size expressed as a percent of the area at risk. We subsequently determined the effect of HT-LVH on the wavefront of myocardial infarction. Dogs were made hypertensive using a single-kidney, single-clip model of renovascular hypertension that produced mean arterial blood pressure (BP) = 141 +/- 3 mm Hg and left ventricular:body weight = 5.8 +/- 0.1 g/kg (p less than 0.05 vs. control animals). Conscious animals with HT-LVH and control animals were subjected to 1 or 3 h of CAO. Infarct and risk areas were measured using triphenyltetrazolium chloride (TTC) stain and barium angiography, respectively. The results suggested that the wavefront of infarction was accelerated in animals with HT-LVH. Further studies suggested that the wavefront of myocardial infarction could be markedly retarded by normalizing blood pressure (nitroprusside) 1 h following CAO. Recent studies in an animal model of HT-LVH suggested that electrophysiological abnormalities occur when these animals were subjected to CAO. Sixty-five percent of animals with HT-LVH had sudden death during CAO compared to 27% of the control group. We studied whether chronic beta-adrenergic blockade would reduce mortality associated with CAO in animals with HT-LVH.(ABSTRACT TRUNCATED AT 250 WORDS)
慢性动脉高血压（HT）和左心室肥厚（LVH）会增加患者急性心肌梗死的发病率和死亡率。在本文中，我们讨论了小柳等人在我们实验室进行的早期研究，这些研究表明，患有慢性HT和LVH（HT-LVH）的动物在遭受急性冠状动脉闭塞（CAO）时，死亡率增加3.5倍，梗死面积增加35%（以危险区域面积的百分比表示）。我们随后确定了HT-LVH对心肌梗死波阵面的影响。使用单肾单夹肾血管性高血压模型使犬产生高血压，该模型使平均动脉血压（BP）=141±3mmHg，左心室重量与体重之比=5.8±0.1g/kg（与对照动物相比，P<0.05）。对清醒的HT-LVH动物和对照动物进行1或3小时的CAO。分别使用氯化三苯基四氮唑（TTC）染色和钡剂血管造影测量梗死区域和危险区域。结果表明，HT-LVH动物的梗死波阵面加速。进一步的研究表明，在CAO后1小时使血压正常化（硝普钠）可显著延缓心肌梗死的波阵面。最近在HT-LVH动物模型中的研究表明，这些动物在遭受CAO时会出现电生理异常。HT-LVH动物中有65%在CAO期间猝死，而对照组为27%。我们研究了慢性β-肾上腺素能阻滞剂是否会降低HT-LVH动物与CAO相关的死亡率。（摘要截短于250字）
