Rembert J C, Greenfield J C
Am J Physiol. 1986 Jun;250(6 Pt 2):H968-73. doi: 10.1152/ajpheart.1986.250.6.H968.
The effect of pacing-induced tachycardia on transmural myocardial blood flow distribution was studied in 16 awake dogs with left ventricular hypertrophy secondary to modified aortic coarctation banding done at 7-10 wk of age. They were studied between 11 and 50 mo of age. In those dogs with mild and moderate left ventricular hypertrophy, the blood flow distribution was normal during resting conditions and remained normal during an increased heart rate of 250 beats/min. In the six dogs with severe hypertrophy (left ventricle/body wt greater than 7.0 g/kg) a reduced flow to the endocardial layers was present during resting conditions (endocardial/epicardial 0.91 +/- 0.09), but during tachycardia the endocardial-to-epicardial ratio normalized to 1.26 +/- 0.08 (mean +/- SEM). These data indicate that, in dogs with significant left ventricular hypertrophy, the vasoregulator mechanism functions adequately to maintain normal transmural myocardial blood flow distribution during tachycardia. In addition, studies were carried out to compare the magnitude of hypertrophy with the hemodynamic load secondary to coarctation banding.
在16只清醒犬中研究了起搏诱导的心动过速对透壁心肌血流分布的影响，这些犬因在7至10周龄时进行改良主动脉缩窄束带术而继发左心室肥厚。它们在11至50月龄时接受研究。在那些轻度和中度左心室肥厚的犬中，静息状态下血流分布正常，心率增加到250次/分钟时仍保持正常。在6只严重肥厚（左心室/体重>7.0 g/kg）的犬中，静息状态下存在心内膜层血流减少（心内膜/心外膜为0.91±0.09），但在心动过速期间，心内膜与心外膜的比率恢复正常，为1.26±0.08（平均值±标准误）。这些数据表明，在有明显左心室肥厚的犬中，血管调节机制在心动过速期间能充分发挥作用，以维持正常的透壁心肌血流分布。此外，还进行了研究以比较肥厚程度与缩窄束带继发的血流动力学负荷。
