Dept. of Biomedical Engineering, Indiana Univ. Purdue Univ. Indianapolis, Indianapolis, IN 46202, USA.
Am J Physiol Heart Circ Physiol. 2011 Jul;301(1):H21-8. doi: 10.1152/ajpheart.00080.2011. Epub 2011 May 6.
Coronary flow reserve (CFR) is an important index of coronary microcirculatory function. The objective of this study was to validate the reproducibility and accuracy of intravascular conductance catheter-based method for measurements of baseline and hyperemic coronary flow velocity (and hence CFR). The absolute coronary blood velocity was determined by measuring the time of transit of a saline injection between two pairs of electrodes (known distance) on a conductance catheter during a routine saline injection without the need for reference flow. In vitro validation was made in the velocity range of 5 to 70 cm/s in reference to the volume collection method. In 10 swine, velocity measurements were compared with those from a flow probe in coronary arteries at different CFR attained by microsphere embolization. In vitro, the mean difference between the proposed method and volume collection was 0.7 ± 1.34 cm/s for steady flow and -0.77 ± 2.22 cm/s for pulsatile flow. The mean difference between duplicate measurements was 0 ± 1.4 cm/s. In in vivo experiments, the flow (product of velocity and lumen cross-sectional area that is also measured by the conductance catheter) was determined in both normal and stenotic vessels and the mean difference between the proposed method and flow probe was -1 ± 12 ml/min (flow ranged from 10 to 130 ml/min). For CFR, the mean difference between the two methods was 0.06 ± 0.28 (range of 1 to 3). Our results demonstrate the reproducibility and accuracy of velocity and CFR measurements with a conductance catheter by use of a standard saline injection. The ability of the combined measurement of coronary lumen area (as previously validated) and current velocity and CFR measurements provides an integrative diagnostic tool for interventional cardiology.
冠状动脉血流储备（CFR）是冠状动脉微循环功能的一个重要指标。本研究的目的是验证基于血管内电导导管的基础和充血性冠状动脉血流速度（因此也是 CFR）测量的重现性和准确性。通过在常规盐水注射期间测量盐水注射在两个电导导管上的两对电极（已知距离）之间的传输时间，来确定绝对冠状动脉血液速度，而无需参考流量。在体外，根据体积收集方法，在 5 至 70 cm/s 的速度范围内进行了验证。在 10 头猪中，通过微球栓塞获得不同 CFR 的冠状动脉中，流速测量与来自流动探针的测量进行了比较。在体外，对于稳定流动，建议的方法与体积收集之间的平均差异为 0.7 ± 1.34 cm/s，对于脉动流动为-0.77 ± 2.22 cm/s。重复测量的平均差异为 0 ± 1.4 cm/s。在体内实验中，在正常和狭窄的血管中同时确定流速（也由电导导管测量的速度和管腔横截面积的乘积），建议的方法与流动探针之间的平均差异为-1 ± 12 ml/min（流速范围为 10 至 130 ml/min）。对于 CFR，两种方法之间的平均差异为 0.06 ± 0.28（范围为 1 至 3）。我们的结果表明，使用标准盐水注射，电导导管可实现流速和 CFR 测量的重现性和准确性。冠状动脉管腔面积（如前已验证）与当前流速和 CFR 测量相结合的能力为介入心脏病学提供了一种综合诊断工具。
