Isaaz K, da Costa A, de Pasquale J P, Cerisier A, Lamaud M
Division of Cardiology, Hôpital Nord, University Jean Monnet, Saint Etienne, France.
J Am Coll Cardiol. 1998 Jul;32(1):42-8. doi: 10.1016/s0735-1097(98)00174-0.
We tested the value of transesophageal Doppler echocardiography (TEDE) for quantitating proximal left coronary artery (LCA) stenosis by using the continuity equation.
The continuity equation applied to a stenosis states that the ratio of the time-velocity integral (TVI) of prestenotic to stenotic flow velocities is equal to the ratio of stenotic to prestenotic cross-sectional areas. TEDE allows the measurement of coronary blood flow velocities within the proximal part of the LCA. METHODS; Forty-one patients with a stenosis of the proximal or mid left anterior descending coronary artery or with a nonostial stenosis of the left main coronary artery were studied. Coronary flow velocities were recorded by TEDE guided by color flow imaging. Prestenotic velocities were recorded by pulsed Doppler echocardiography and transstenotic velocities were recorded by pulsed or high pulse repetition frequency or continuous wave Doppler echocardiography. The prestenotic and transstenotic diastolic TVIs were calculated and the TEDE-derived percent area stenosis was calculated as (1 - TVI ratio) x 100. Quantitative angiography lesion analysis was performed using a computer-assisted automated edge-detection system.
TEDE recordings were successful in 35 of the 41 patients. A good linear correlation was found between TEDE and quantitative angiographically derived percent area stenosis (r = 0.89, p = 0.0001, SEE 5.7). However, TEDE measurements underestimated the actual percent area stenosis (slope of regression 0.54). A better agreement (slope 1.08) was obtained after dividing prestenotic velocity by 2 in the continuity equation, based on the assumption of a parabolic cross-sectional velocity profile in the prestenotic segment.
TEDE may be used for quantitating stenosis of the proximal part of the LCA with the use of a modified continuity equation that takes into account the parabolic velocity profile in the normal prestenotic segment.
我们通过使用连续性方程来测试经食管多普勒超声心动图（TEDE）对定量评估左冠状动脉（LCA）近端狭窄的价值。
应用于狭窄部位的连续性方程表明，狭窄前与狭窄处血流速度的时间-速度积分（TVI）之比等于狭窄处与狭窄前横截面积之比。TEDE能够测量LCA近端的冠状动脉血流速度。方法：对41例左前降支近端或中段狭窄或左主干非开口处狭窄的患者进行研究。在彩色血流成像引导下，通过TEDE记录冠状动脉血流速度。用脉冲多普勒超声心动图记录狭窄前速度，用脉冲或高脉冲重复频率或连续波多普勒超声心动图记录跨狭窄速度。计算狭窄前和跨狭窄舒张期TVI，并将TEDE得出的面积狭窄百分比计算为（1 - TVI比值）×100。使用计算机辅助自动边缘检测系统进行定量血管造影病变分析。
41例患者中有35例成功进行了TEDE记录。发现TEDE与定量血管造影得出的面积狭窄百分比之间存在良好的线性相关性（r = 0.89，p = 0.0001，标准误5.7）。然而，TEDE测量低估了实际面积狭窄百分比（回归斜率为0.54）。基于狭窄前段横截面积速度分布呈抛物线形的假设，在连续性方程中将狭窄前速度除以2后，获得了更好的一致性（斜率为1.08）。
TEDE可用于通过使用修正的连续性方程来定量评估LCA近端的狭窄，该方程考虑了正常狭窄前段的抛物线形速度分布。
