School of Dynamic Systems, Department of Mechanical Engineering, University of Cincinnati, Cincinnati, Ohio 45220, USA.
Am J Physiol Heart Circ Physiol. 2012 Apr 15;302(8):H1563-73. doi: 10.1152/ajpheart.01042.2011. Epub 2012 Jan 27.
Diagnosis of the ischemic power of epicardial stenosis with concomitant microvascular disease (MVD) is challenging during coronary interventions, especially under variable hemodynamic factors like heart rate (HR). The goal of this study is to assess the influence of variable HR and percent area stenosis (%AS) in the presence of MVD on pressure drop coefficient (CDP; ratio of transstenotic pressure drop to the distal dynamic pressure) and lesion flow coefficient (LFC; ratio of %AS to the CDP at the throat region). We hypothesize that CDP and LFC are independent of HR. %AS and MVD were created using angioplasty balloons and 90-μm microspheres, respectively. Simultaneous measurements of pressure drop (DP) and velocity were done in 11 Yorkshire pigs. Fractional flow reserve (FFR), CDP, and LFC were calculated for the groups HR < 120 and HR > 120 beats/min, %AS < 50 and %AS > 50, and additionally for DP < 14 and DP > 14 mmHg, and analyzed using regression and ANOVA analysis. Regression analysis showed independence between HR and the FFR, CDP, and LFC while it showed dependence between %AS and the FFR, CDP, and LFC. In the ANOVA analysis, for the HR < 120 beats/min and HR > 120 beats/min groups, the values of FFR (0.82 ± 0.02 and 0.82 ± 0.02), CDP (83.15 ± 26.19 and 98.62 ± 26.04), and LFC (0.16 ± 0.03 and 0.15 ± 0.03) were not significantly different (P > 0.05). However, for %AS < 50 and %AS > 50, the FFR (0.89 ± 0.02 and 0.75 ± 0.02), CDP (35.97 ± 25.79.10 and 143.80 ± 25.41), and LFC (0.09 ± 0.03 and 0.22 ± 0.03) were significantly different (P < 0.05). A similar trend was observed between the DP groups. Under MVD conditions, FFR, CDP, and LFC were not significantly influenced by changes in HR, while they can significantly distinguish %AS and DP groups.
在冠状动脉介入治疗中，对于伴有微血管疾病（MVD）的心外膜狭窄的缺血能力的诊断具有挑战性，尤其是在心率（HR）等可变血流动力学因素下。本研究的目的是评估在 MVD 存在的情况下，可变 HR 和百分比面积狭窄（%AS）对压力降系数（CDP；跨狭窄压力降与远端动力压力之比）和病变流量系数（LFC；狭窄处区域的%AS 与 CDP 之比）的影响。我们假设 CDP 和 LFC 与 HR 无关。使用球囊血管成形术和 90-μm 微球分别创建%AS 和 MVD。在 11 头约克夏猪中同时进行压力降（DP）和速度的测量。为 HR < 120 和 HR > 120 次/分钟、%AS < 50 和%AS > 50 以及 DP < 14 和 DP > 14 mmHg 的组计算了血流储备分数（FFR）、CDP 和 LFC，并使用回归和 ANOVA 分析进行了分析。回归分析表明 HR 与 FFR、CDP 和 LFC 之间存在独立性，而%AS 与 FFR、CDP 和 LFC 之间存在依赖性。在 ANOVA 分析中，对于 HR < 120 次/分钟和 HR > 120 次/分钟组，FFR（0.82 ± 0.02 和 0.82 ± 0.02）、CDP（83.15 ± 26.19 和 98.62 ± 26.04）和 LFC（0.16 ± 0.03 和 0.15 ± 0.03）的值无显著差异（P > 0.05）。然而，对于%AS < 50 和%AS > 50，FFR（0.89 ± 0.02 和 0.75 ± 0.02）、CDP（35.97 ± 25.79 和 143.80 ± 25.41）和 LFC（0.09 ± 0.03 和 0.22 ± 0.03）值有显著差异（P < 0.05）。在 DP 组中观察到类似的趋势。在 MVD 条件下，FFR、CDP 和 LFC 不受 HR 变化的显著影响，而它们可以显著区分%AS 和 DP 组。
