Department of Molecular and Clinical Medicine, Sahlgrenska Academy at University of Gothenburg, Bruna stråket 16, SE 413 45 Gothenburg, Sweden.
Eur Heart J Cardiovasc Imaging. 2014 Feb;15(2):152-7. doi: 10.1093/ehjci/jet079. Epub 2013 Jul 5.
Stress-induced cardiomyopathy (SIC) is an important differential diagnosis to acute myocardial infarction (AMI) that is associated with significant morbidity and mortality. The typical hallmark of SIC is left-ventricular apical akinesia but preserved function in basal segments. Catecholamines are postulated to play an important role in SIC but the precise pathophysiology is incompletely understood. Whether myocardial perfusion of the affected segments is impaired in SIC has been debated and remains unknown.
Myocardial contrast echocardiography (MCE) was used to study regional myocardial perfusion in a rat model of SIC. Twelve rats received 50 mg/kg isoproterenol (ISO) i.p. and were continuously monitored by MCE. Apical and basal perfusion were estimated and expressed as a ratio at baseline, 5, 10, 20, 30, 40, 50, 60, 70, 80, and 90 min post-ISO. The rats developed typical apical ballooning after 43 ± 9 min post-ISO injection. The ratio of apical:basal perfusion was close to 1.00 at all time-points and never dropped below 0.89 (95% CI never extended below 0.73). Light and electron microcoscopical investigation revealed no structural damage of myocardial vessels.
Apical perfusion is not impaired in the early phase of SIC in this rat model.
应激性心肌病（SIC）是急性心肌梗死（AMI）的重要鉴别诊断，与较高的发病率和死亡率相关。SIC 的典型特征是左心室心尖部无运动，但基底段收缩功能正常。儿茶酚胺被认为在 SIC 中起重要作用，但确切的病理生理学机制尚不完全清楚。SIC 受累节段的心肌灌注是否受损一直存在争议，目前仍不清楚。
使用心肌声学造影（MCE）研究 SIC 大鼠模型中的区域性心肌灌注。12 只大鼠接受 50mg/kg 异丙肾上腺素（ISO）腹腔注射，并通过 MCE 进行连续监测。在基线、ISO 注射后 5、10、20、30、40、50、60、70、80 和 90min 时分别估计心尖部和基底段的灌注，并表示为比值。ISO 注射后 43±9min 时，大鼠出现典型的心尖部球囊样变。心尖部：基底部灌注比值在所有时间点均接近 1.00，从未降至 0.89 以下（95%CI 从未低于 0.73）。光镜和电镜检查显示心肌血管无结构损伤。
在该 SIC 大鼠模型的早期阶段，心尖部灌注未受损。
