Effect of heart rate on myocardial blood flow in dogs with left ventricular hypertrophy.
Effect of heart rate on myocardial blood flow in dogs with left ventricular hypertrophy.
复制标题
心率对左心室肥厚犬心肌血流量的影响。
DOI：
10.1152/ajpheart.1980.239.5.h621
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Bache,RJ
中科院分区：
文献类型：
--
作者：
Vrobel,TR;Ring,WS;Anderson,RW;Emery,RW;Bache,RJ
由于之前的建议表明肥大心脏的心内膜下灌注可能不足，因此进行本研究是为了检查慢性左心室肥大犬的跨壁心肌血流对起搏诱导的心动过速的反应。结扎5-6周龄幼犬的升主动脉，造成心肌肥厚，与对照犬相比，左心室相对质量平均增加87%。使用放射性核素标记的微球在心室起搏期间以100、200和250次/min的心率检查心肌血流量。在心率为100次/min时，两组犬每单位心肌质量的平均血流量相似，并且在两组动物的起搏过程中有规律地增加。在正常犬中，心率增加并不改变心肌血流的透壁模式，但在左心室肥大的动物中，以250次/min起搏导致灌注从内膜下显著重新分布，心内膜下/心外膜下血流比值由100次/min时的1.03 ± 0.08降至250次/min时的0.83 ± 0.06（P < 0.01）。这种远离内膜下的血流再分布在乳头肌和介入的左心室侧壁区域尤其明显。
Because of the previous suggestion that subendocardial perfusion may be inadequate in the hypertrophied heart, this study was carried out to examine the response of transmural myocardial blood flow to pacing induced tachycardia in dogs with chronic left ventricular hypertrophy. Myocardial hypertrophy, produced by banding the ascending aorta of puppies at 5-6 wk of age, resulted in an 87% average increase in relative left ventricular mass compared with the control dogs. Myocardial blood flow was examined during ventricular pacing at heart rates of 100, 200, and 250 beats/min using radionuclide-labeled microspheres. Mean blood flow per unit myocardial mass was similar in the two groups of dogs at a heart rate of 100 beats/min and increased regularly during pacing in both groups of animals. Increasing heart rates did not change the transmural pattern of myocardial blood flow in the normal dogs, but in the animals with left ventricular hypertrophy pacing at 250 beats/min resulted in a significant redistribution of perfusion away from the subendocardium, with the ratio of subendocardial/subepicardial blood flow falling from 1.03 +/- 0.08 at 100 beats/min to 0.83 +/0 0.06 at 250 beats/min (P < 0.01). This redistribution of blood flow away from the subendocardium was especially marked in the regions encompassing the papillary muscles and the intervening left ventricular lateral wall.