Schühlen H, Eigler N L, Zeiher A M, Rombach M M, Whiting J S
1. Medizinische Klinik, Technischen Universität, Klinikum rechts der Isar, Munich, Germany.
Circulation. 1994 Jul;90(1):163-71. doi: 10.1161/01.cir.90.1.163.
Impulse response analysis of digital coronary angiographic images calculates a parameter known as the mean transit time of the microcirculation (Tmicro). This has been shown to accurately assess the regional microcirculatory response to proximal stenosis in relation to flow. Our goal was to apply impulse response analysis to patients undergoing successful angioplasty and to quantify the induced physiological changes with respect to quantitative angiographic measurements of stenosis dimensions.
We studied 24 patients before and after successful single-vessel percutaneous transluminal coronary angioplasty (PTCA). Minimal luminal stenosis area was increased from 0.9 +/- 0.6 before PTCA to 4.1 +/- 1.3 mm2 after PTCA (P < .0001). In all patients this was accompanied by an increase in the inverse of Tmicro (Tmicro-1), from 8.5 +/- 3.0 to 26.5 +/- 9.0 min-1 (P < .0001) with a linear correlation between Tmicro-1 and minimal luminal stenosis area (r = .73; SEE = 7.74). Stenosis flow reserve, estimated by integration of stenosis dimensions, increased in all patients from 1.8 +/- 1.0 to 4.5 +/- 0.4 after PTCA (P < .01). A comparison of Tmicro-1 with stenosis flow reserve revealed a nonlinear relation. In 16 patients undergoing PTCA of the left anterior descending or circumflex artery, contrast injections into the left main stem allowed simultaneous measurements of Tmicro-1 in the adjacent, nonstenotic artery. Adjacent artery Tmicro-1 did not change after PTCA (25.8 +/- 6.2 compared with 25.6 +/- 6.8 min-1 before PTCA; P = NS); moreover, Tmicro-1 of the dilated artery measured after PTCA was equivalent to the nonstenotic adjacent artery, indicating normalization of microcirculatory responses.
These data suggest that Tmicro-1 determined by digital angiographic impulse response analysis of a single contrast injection under resting flow conditions may be a practical method to assess the regional microcirculatory response to changes in stenosis severity effected by coronary angioplasty.
数字冠状动脉造影图像的脉冲响应分析可计算出一个称为微循环平均通过时间（Tmicro）的参数。研究表明，该参数能准确评估局部微循环对近端狭窄与血流相关的反应。我们的目标是将脉冲响应分析应用于成功接受血管成形术的患者，并根据狭窄程度的定量血管造影测量来量化所诱发的生理变化。
我们研究了24例患者在成功进行单支血管经皮腔内冠状动脉成形术（PTCA）前后的情况。最小管腔狭窄面积从PTCA前的0.9±0.6增加到PTCA后的4.1±1.3mm²（P<.0001）。在所有患者中，这伴随着Tmicro的倒数（Tmicro-1）增加，从8.5±3.0增加到26.5±9.0min⁻¹（P<.0001），且Tmicro-1与最小管腔狭窄面积之间存在线性相关性（r=.73；SEE=7.74）。通过整合狭窄程度估算的狭窄血流储备在所有患者中从PTCA前的1.8±1.0增加到PTCA后的4.5±0.4（P<.01）。Tmicro-1与狭窄血流储备的比较显示出非线性关系。在16例接受左前降支或回旋支PTCA的患者中，向左主干内注射造影剂可同时测量相邻非狭窄动脉的Tmicro-1。PTCA后相邻动脉的Tmicro-1未发生变化（PTCA后为25.8±6.2，PTCA前为25.6±6.8min⁻¹；P=无显著性差异）；此外，PTCA后扩张动脉的Tmicro-1与相邻非狭窄动脉相当，表明微循环反应恢复正常。
这些数据表明，在静息血流条件下通过单次造影剂注射的数字血管造影脉冲响应分析确定的Tmicro-1可能是一种评估冠状动脉成形术引起的狭窄严重程度变化的局部微循环反应的实用方法。
