Cardiac sympathetic nerve activity in the non-infarcted region in patients with a prior myocardial infarction and left ventricular remodeling

左室重构是心肌梗死后左室远端非梗死区室壁肥厚伴左室腔扩大的一种病理过程，与收缩性心力衰竭密切相关。因此，我们评估了这个问题的机制，从心脏交感神经功能的角度在这样一个地区的16例患者与先前的心肌梗死使用正电子发射断层扫描（PET）和放射性标记的儿茶酚胺类似物11 C-羟麻黄碱（HED）作为标记神经元的儿茶酚胺摄取功能。HED保留指数通过将30至40分钟的心肌示踪剂活性标准化为11 C活性输入函数的积分来确定。已知心脏突触前儿茶酚胺摄取依赖于心肌血流量。因此，我们在同一天使用13 N-氨PET定量测量了局部心肌血流量（MBF）。还使用超声心动图确定LV容积。该研究方案也是 ...更多信息 10例健康志愿者作为正常对照。结果如下：有心肌梗死史的患者左室舒张末期容积指数显著大于正常对照组（69.6±15.9 vs 47.2±13.4 ml/m2，p<0.01）。在既往MI患者中观察到明显的LV重构。在正常对照组中，左室前壁的心肌血流量和HED保留指数最大。心肌梗死患者远端非梗死区MBF显著低于正常对照组前壁MBF（0.76± 0.14vs0.88 ± 0.13ml/g/min，p<0.05）。HED的保留指数（8.06± 1.22vs7.03 ± 1.12%/min，P<0.01）及经相应区域血流校正的滞留指数（10.8± 1.7 vs 8.1± 0.9%/min/MBF，p<0.001）在远端非梗死区显著高于正常对照前壁。与对照组相比，既往MI患者的远端非梗死区交感神经突触前儿茶酚胺摄取量更大。这一发现表明，心肌交感神经功能亢进的患者与先前的MI和LV重构与收缩性心力衰竭的病理生理学。少

Left ventricular (LV) remodeling is observed as LV cavity expansion with wall hypertrophy in the remote non-infarcted region in the LVs after myocardial infarction (MI) and is closely involved in systolic heart failure. Accordingly, we assessed the mechanism of this issue from the viewpoint of cardiac sympathetic nerve function in such a region in 16 patients with a prior myocardial infarction using positron emission tomography (PET) and radiolabelled catecholamine analogue 11C-hydroxyephedrine (HED) as a marker for neuronal catecholamine uptake function. HED retention index was determined by normalizing myocardial tracer activity from 30 to 40 minutes to the integral of the 11C activity input function. Cardiac presynaptic catecholamine uptake is known to depend on myocardial blood flow. Thus, we quantitatively measured regional myocardial blood flow （MBF) using PET with 13N-ammonia on the same day. LV volumes were also determined using echocardiography. This study protocol was also do … More ne in 10 healthy volunteers served as normal controls. Results: LV end-diastolic volume index was significantly larger in patients with a prior MI than in normal controls (69.6±15.9 vs 47.2±13.4 ml/m2, p<0.01). An apparent LV remodeling was observed in patients with a prior MI. In normal controls, myocardial blood flow and HED retention index were largest in the LV anterior wall. MBF was significantly less in the remote non-infarcted region in patients with a MI compared with that in the anterior wall in normal controls (0.76±0.14 vs 0.88 ± 0.13 ml/g/min, p<0.05). The retention index of HED (8.06±1.22 vs 7.03 ±1.12 %/min, p<0.01) and the retention index corrected by the blood flow in the corresponding area (10.8± 1.7 vs 8.1± 0.9 %/min/MBF, p<0.001) were significantly higher in the remote non-infarcted region than in the anterior wall of normal controls.Conclusion: A greater amount of sympathetic presynaptic catecholamine uptake is observed in the remote non-infarcted region in patients with a prior MI compared with that in controls. This finding suggests that hyperactivity of myocardial sympathetic nerve function in patients with a prior MI and LV remodeling is related to the pathophysiology of systolic heart failure. Less