Gewirtz H, Fischman A J, Abraham S, Gilson M, Strauss H W, Alpert N M
Department of Medicine, Rhode Island Hospital, Providence.
J Am Coll Cardiol. 1994 Mar 15;23(4):851-9. doi: 10.1016/0735-1097(94)90629-7.
This study tested the hypothesis that nonviable myocardium can be identified by quantitative measurements of regional myocardial blood flow obtained using positron emission tomography in conjunction with a mathematical model of nitrogen-13 (N-13) ammonia tracer kinetics.
Under steady state basal conditions there is a minimal level of blood flow required to sustain myocardial viability. Therefore, the hypothesis predicts that regions with flow below a certain threshold are likely to be composed primarily of scar.
Studies were conducted in 26 patients with chronic myocardial infarction. Positron emission tomographic measurements of basal regional myocardial blood flow (N-13 ammonia) and fluorine-18 (F-18) fluorodeoxyglucose uptake were made and correlated with information about coronary anatomy and regional wall motion to assess myocardial viability.
In patients with chronic myocardial infarction, normal zone blood flow (0.81 +/- 0.32 ml/min per g [mean +/- SD]) was greater (p < 0.02) than that of border zones (0.59 +/- 0.29 ml/min per g), which in turn exceeded (p < 0.001) that of infarct zone flow (0.27 +/- 0.17 ml/min per g). Good correlation was noted between relative F-18 fluorodeoxyglucose uptake and relative regional myocardial blood flow in all zones (r = 0.63, p < 0.001). Mismatch between blood flow and F-18 fluorodeoxyglucose uptake, with a single exception, was not observed in any segment with blood flow < 0.25 ml/min per g. All dyskinetic segments (n = 5) also had blood flow < 0.25 ml/min per g. In contrast, 43 of 45 myocardial segments (23 patients) with normal contraction or only mild hypokinesia had flow > or = 0.39 ml/min per g (average flow 0.78 +/- 0.35 ml/min per g).
In patients with chronic myocardial infarction, myocardial viability is unlikely when basal regional myocardial blood flow is < 0.25 ml/min per g. Average basal flow in segments with normal or nearly normal wall motion is 0.78 +/- 0.35 ml/min per g. Thus, positron emission tomographic measurement of regional myocardial blood flow is helpful in identifying nonviable myocardium in these patients.
本研究检验了一项假设，即通过使用正电子发射断层扫描结合氮 - 13（N - 13）氨示踪动力学数学模型获得的局部心肌血流定量测量，可以识别无活性心肌。
在稳态基础条件下，维持心肌存活需要最低水平的血流。因此，该假设预测血流低于特定阈值的区域可能主要由瘢痕组织构成。
对26例慢性心肌梗死患者进行了研究。进行了正电子发射断层扫描测量基础局部心肌血流（N - 13氨）和氟 - 18（F - 18）氟脱氧葡萄糖摄取，并将其与冠状动脉解剖结构和局部室壁运动信息相关联，以评估心肌存活情况。
在慢性心肌梗死患者中，正常区域血流（0.81±0.32 ml/min per g [平均值±标准差]）高于（p < 0.02）边缘区域（0.59±0.29 ml/min per g），而边缘区域血流又超过（p < 0.001）梗死区域血流（0.27±0.17 ml/min per g）。在所有区域，相对F - 18氟脱氧葡萄糖摄取与相对局部心肌血流之间存在良好的相关性（r = 0.63，p < 0.001）。在任何血流<0.25 ml/min per g的节段中，除了一个例外，未观察到血流与F - 18氟脱氧葡萄糖摄取不匹配的情况。所有运动障碍节段（n = 5）的血流也<0.25 ml/min per g。相比之下，45个心肌节段中的43个（2３例患者）收缩正常或仅有轻度运动减弱，其血流≥0.39 ml/min per g（平均血流0.78±0.35 ml/min per g）。
在慢性心肌梗死患者中，当基础局部心肌血流<0.25 ml/min per g时，心肌存活的可能性不大。室壁运动正常或接近正常节段的平均基础血流为0.78±0.35 ml/min per g。因此，正电子发射断层扫描测量局部心肌血流有助于识别这些患者中的无活性心肌。
