Ochiai K, Shimada T, Murakami Y, Ishibashi Y, Sano K, Kitamura J, Inoue S, Murakami R, Kawamitsu H, Sugimura K
Fourth Division, Department of Internal Medicine, Shimane Medical University, Izumo, Japan.
J Cardiovasc Magn Reson. 1999;1(3):247-56. doi: 10.3109/10976649909088337.
With the advent of thrombolytic therapy, hemorrhagic myocardial infarction (HMI) has been observed in experimental and human autopsy studies. However, its clinical implications remain undetermined, because of the absence of a reliable method to detect its presence in vivo. This study was designed to evaluate the clinical implications of HMI detected by magnetic resonance (MR) imaging in vivo after coronary reperfusion. Thirty-nine patients with acute myocardial infarction (AMI) were studied. Percutaneous transluminal coronary angioplasty (PTCA) was used to reopen the occluded coronary artery. Electrocardiogram (ECG)-gated T2*-weighted gradient-echo MR imaging was performed to detect intramyocardial hemorrhage, using a 1.5-T magnet within 2 weeks after coronary reperfusion (average, 5.7 days). Thirteen patients (33%) showed intramyocardial hemorrhage as a distinct hypointense zone by gradient-echo MR imaging and 26 patients showed homogeneous intensity consistent with absence of intramyocardial hemorrhage. Coronary angiograms showed lesser development of collateral flow in the patients with HMI than in those without (81% vs. 37%). Infarct size, estimated 1 month after coronary reperfusion by thallium-201 scintigraphy, was larger among patients with HMI than in those without (37 +/- 14% vs. 21 +/- 14%, respectively, p < 0.05). Left ventricular ejection fraction at 1 month follow-up showed less recovery in patients with HMI than in those without (47 +/- 9 to 51 +/- 10%; p = 0.47, vs. 53 +/- 10 to 60 +/- 9%, respectively, p < 0.05). ECG-gated T2*-weighted gradient-echo MR imaging offers a noninvasive means of detection of intramyocardial hemorrhage in patients with reperfused AMI. HMI occurred even after primary PTCA and may be a common finding associated with severely injured myocardium.
随着溶栓治疗的出现，在实验研究和人体尸检研究中已观察到出血性心肌梗死（HMI）。然而，由于缺乏在体内检测其存在的可靠方法，其临床意义仍未确定。本研究旨在评估冠状动脉再灌注后通过磁共振（MR）成像在体内检测到的HMI的临床意义。对39例急性心肌梗死（AMI）患者进行了研究。采用经皮腔内冠状动脉成形术（PTCA）重新开通闭塞的冠状动脉。在冠状动脉再灌注后2周内（平均5.7天），使用1.5-T磁体进行心电图（ECG）门控的T2 *加权梯度回波MR成像，以检测心肌内出血。13例患者（33%）通过梯度回波MR成像显示心肌内出血为明显的低信号区，26例患者显示均匀信号强度，提示无心肌内出血。冠状动脉造影显示，HMI患者的侧支血流发展程度低于无HMI患者（分别为81%对37%）。通过铊-201闪烁显像在冠状动脉再灌注1个月后估计的梗死面积，HMI患者大于无HMI患者（分别为37±14%对21±14%，p<0.05）。随访1个月时，HMI患者的左心室射血分数恢复程度低于无HMI患者（分别为47±9至51±10%；p = 0.47，而无HMI患者为53±10至60±9%，p<0.05）。ECG门控的T2 *加权梯度回波MR成像为检测再灌注AMI患者的心肌内出血提供了一种非侵入性方法。即使在初次PTCA后也会发生HMI，并且可能是与严重受损心肌相关的常见发现。
