PRESSURE-FLOW CHARACTERISTICS OF CORONARY STENOSES IN UNSEDATED DOGS AT REST AND DURING CORONARY VASODILATION
PRESSURE-FLOW CHARACTERISTICS OF CORONARY STENOSES IN UNSEDATED DOGS AT REST AND DURING CORONARY VASODILATION
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DOI：
10.1161/01.res.43.2.242
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发表时间：
1978-01-01
影响因子：
20.1
通讯作者：
GOULD, KL
中科院分区：
文献类型：
--
作者：
GOULD, KL
研究了10只未麻醉犬在静息状态和药物冠脉舒张过程中100条左旋狭窄血管的压力-血流特性。静息时，狭窄引起的压力损失（. delta . p）与动脉血流速度(V)的关系式为。delta。P = FV + SV2，其中F为狭窄段黏性摩擦压力损失系数，S为狭窄发散端流动分离压力损失系数。静息冠状血流总压损失中，粘性摩擦引起的线性项占65%，流动分离引起的非线性项占35%。在冠状动脉血管舒张后的冠状动脉血流峰值，粘性摩擦造成的压力损失占总压力损失的33%，流动分离造成的压力损失占总压力损失的67%。大流量时的压力梯度-速度关系具有相同的一般方程，但与静止梯度-速度关系预测的相比，系数S的比例更大，与流动分离相关的压力损失更大。基于静态梯度-速度方程预测的高冠状动脉血流速度下的压力损失仅为实验观察到的冠状动脉血流峰值压力梯度的64%。冠状动脉扩张后分离损失的增加可能是由于与固定狭窄段相邻的心外膜动脉扩张导致更严重的相对狭窄百分比和狭窄远端更大的发散角，这是分离损失的主要几何决定因素。
The pressure-flow characteristics of 100 left circumflex stenoses in 10 instrumented unsedated dogs were studied under resting conditions and during pharmacological coronary vasodilation. At rest, the pressure loss (.DELTA.P) due to stenosis and arterial flow velocity (V) were related by the equation, .DELTA.P = FV + SV2, where F is the coefficient of pressure loss due to viscous friction in the stenotic segment and S is the coefficient of pressure loss due to flow separation at the diverging end of the stenosis. The linear term due to viscous friction accounted for 65% and the nonlinear term due to flow separation accounted for 35% of the total pressure loss at resting coronary flow. At peak coronary flow after coronary vasodilation, the pressure loss due to viscous friction accounted for 33% and pressure loss due to flow separation, for 67%, of the total pressure loss. The pressure gradient-velocity relationship at high flows was characterized by the same general equation but with proportionately larger values of the coefficient S and greater pressure loss associated with flow separation than predicted by the resting gradient-velocity relationship. The pressure loss predicted for high coronary flow velocities on the basis of the gradient-velocity equation at rest was only 64% of the experimentally observed pressure gradient at peak coronary flow. The augmented separation loss following coronary vasodilation was probably due to dilation of the epicardial artery adjacent to the fixed stenotic segment causing more severe relative percent narrowing and a larger divergence angle at the distal end of the stenosis, the primary geometric determinants of separation losses.