MYOCARDIAL BLOOD-FLOW DURING EXERCISE IN DOGS WITH LEFT-VENTRICULAR HYPERTROPHY PRODUCED BY AORTIC BANDING AND PERINEPHRITIC HYPERTENSION
MYOCARDIAL BLOOD-FLOW DURING EXERCISE IN DOGS WITH LEFT-VENTRICULAR HYPERTROPHY PRODUCED BY AORTIC BANDING AND PERINEPHRITIC HYPERTENSION
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DOI：
10.1161/01.cir.76.4.835
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发表时间：
1987-10-01
期刊：
影响因子：
37.8
通讯作者：
HOMANS, DC
中科院分区：
文献类型：
--
作者：
BACHE, RJ;DAI, XZ;HOMANS, DC
本研究验证了一个假设，即对于相似程度的左心室肥厚，与捆绑升主动脉产生的肥厚相比，与动脉高血压相关的舒张期冠状动脉灌注压升高会促进心内膜下血流量。7只成年犬伴有肾周性高血压，9只成年犬伴有升主动脉捆扎导致左心室肥厚。左心室/体重比为6.15 +-。高血压动物0.59 g/kg, +- 6.87 g/kg。主动脉束带犬为0.47 g/kg，而主动脉束带犬为4.23。7只正常犬0.23 g/kg （p < 0.01）。研究在休息和两个阶段的跑步机运动中进行，达到195和260次/分钟的心率。高血压动物的主动脉舒张压升高，但主动脉束带犬没有升高。主动脉束带犬的收缩期延长，而高血压犬无此现象。在所有三组动物中，微球测量的每克心肌平均血流量在休息和轻度运动时相似，而在剧烈运动时，两组肥厚的血流量均显著大于正常。在正常狗的心内膜下/心外膜下（endo/epi）血流比率在运动期间没有显著变化。在肥厚的两组中，endo/epi比值在休息时正常，但在运动时显著下降。在剧烈运动时，endo/epi比值降至0.73 +-。主动脉束带犬为0.08，主动脉束带犬为1.07。高血压犬0.12 （p < 0.01）。这些数据表明，高血压动物舒张期冠状动脉灌注压的增加促进了在剧烈运动时肥厚的左心室心内膜下的灌注。
This study tested the hypothesis that for similar degrees of left ventricular hypertrophy, subendocardial blood flow would be facilitated by the increased diastolic coronary perfusion pressure associated with arterial hypertension, as compared with hypertrophy produced by banding the ascending aorta. Left ventricular hypertrophy was produced with perinephritic hypertension in seven adult dogs and by banding the asceding aorta in nine adult dogs. Left ventricular/body weight ratios were 6.15 .+-. 0.59 g/kg in the hypertensive animals and 6.87 .+-. 0.47 g/kg in dogs with aortic banding, as compared with 4.23 .+-. 0.23 g/kg in seven normal dogs (p < .01). Studies were performed at rest and during two stages of treadmill exercise to achieve heart rates of 195 and 260 beats/min. Diastolic aortic pressure was increased in animals with hypertension but not in dogs with aortic banding. Systolic ejection period was prolonged in dogs with aortic banding but not in hypertensive dogs. Mean blood flow per gram of myocardium measured with microspheres was similar at reat and during light exercise in all three groups of animals, whereas during heavy exercise blood flow was significantly greater than normal in both groups with hypertrophy. In normal dogs subendocardial/subepicardial (endo/epi) flow ratios did not change significantly during exercise. In both groups with hypertrophy, endo/epi ratios were normal at rest but decreased significantly during exercise. During heavy exercise the endo/epi ratio decreased to 0.73 .+-. 0.08 in dogs with aortic banding as compared with 1.07 .+-. 0.12 in hypertensive dogs (p < .01). These data suggest that the increased diastolic coronary perfusion pressure in hypertensive animals facilitated perfusion of the subendocardium of the hypertrophied left ventricle during heavy exercise.