Sharkey Scott W
Cardiovascular Research Division, Minneapolis Heart Institute Foundation, Minneapolis, MN 55407, USA.
J Electrocardiol. 2008 Nov-Dec;41(6):621-5. doi: 10.1016/j.jelectrocard.2008.06.015. Epub 2008 Sep 13.
An important subset of patients (approximately 10%) with chest pain and ST-segment elevation on initial electrocardiogram (ECG) do not have acute coronary occlusion. In our experience, 5% of women presenting with chest pain and ST-segment elevation are proven to have the newly recognized syndrome of tako-tsubo (stress) cardiomyopathy (TC). Patients with TC present with clinical and electrocardiographic features mimicking ST-segment elevation anterior myocardial infarction due to left anterior descending (LAD) occlusion. The initial and subsequent ECG findings in TC are therefore of clinical importance. Thirty-three consecutive patients with TC were identified from within a single institution community-based cardiology practice. All were female aged 32 to 90 years (mean, 68 years) with acute chest pain associated with an emotional or physical stressful event, and akinesia of the mid-distal left ventricle but without significant atherosclerotic coronary artery obstruction. All patients with TC presented with anterior ST-segment elevation most marked in leads V(1) to V(5), maximal in leads V(2) and V(3). Distribution of ST-segment elevation was similar to 44 female control patients with acute (LAD) occlusion. ST-segment elevation magnitude was less in patients with TC (1.4 +/- 1.5 mm) than in patients with LAD occlusion (2.4 +/- 2.2 mm) (P < .001) but with considerable overlap. Left ventricular ejection fraction (LVEF) was significantly lower in TC patients (29% +/- 9%) than in patients with LAD occlusion (42% +/- 13%) (P < .05). Peak troponin T was significantly lower in patients with TC (0.64 +/- 0.86 ng/mL) than in patients with LAD occlusion (3.88 +/- 4.9 ng/mL) (P < .0001). Cardiovascular magnetic resonance imaging detected myocardial necrosis in 1 patient with TC. At follow-up, LVEF returned to normal (> 50%) in all patients with TC. In patients with TC, ECG evolution was characterized by resolution of ST-segment elevation, appearance of T-wave inversion (most marked in precordial leads V(3)-V(6) and limb leads aVL, I, and -aVR), QTc interval prolongation (378 +/- 60 milliseconds [initial] vs 470 +/- 72 milliseconds [follow-up], P < .05), and reappearance of precordial R waves. In conclusion, patients with TC frequently present with anterior ST-segment elevation, which cannot be reliably distinguished from that of acute LAD occlusion. In TC, the combination of minimal troponin release, absent delayed hyperenhancement on cardiac magnetic resonance imaging (in most of patients), and return to normal LVEF is consistent with the presence of significant myocardial stunning. The ECG evolution of progressive T-wave inversion, QTc interval lengthening, and R-wave reappearance could be the electrophysiologic manifestation of an underlying stunned myocardium in this condition.
初始心电图（ECG）表现为胸痛伴ST段抬高的患者中有一个重要亚组（约10%）并无急性冠状动脉闭塞。根据我们的经验，因胸痛伴ST段抬高前来就诊的女性患者中有5%被证实患有新发现的应激性心肌病（TC，又称“章鱼壶心肌病”）综合征。TC患者的临床和心电图特征与因左前降支（LAD）闭塞所致的ST段抬高型前壁心肌梗死相似。因此，TC患者最初及后续的心电图表现具有临床重要性。我们从一家社区心脏病专科医院连续确定了33例TC患者。所有患者均为女性，年龄32至90岁（平均68岁），有与情绪或身体应激事件相关的急性胸痛，左心室中远端运动减弱，但无明显的冠状动脉粥样硬化阻塞。所有TC患者均表现为前壁ST段抬高，在V（1）至V（5）导联最为明显，在V（2）和V（3）导联最大。ST段抬高的分布与44例急性LAD闭塞的女性对照患者相似。TC患者的ST段抬高幅度（1.4±1.5毫米）低于LAD闭塞患者（2.4±2.2毫米）（P<0.001），但有相当程度的重叠。TC患者的左心室射血分数（LVEF）（29%±9%）显著低于LAD闭塞患者（42%±13%）（P<0.05）。TC患者的肌钙蛋白T峰值（0.64±0.86纳克/毫升）显著低于LAD闭塞患者（3.88±4.9纳克/毫升）（P<0.0001）。心血管磁共振成像检测到1例TC患者存在心肌坏死。随访时，所有TC患者的LVEF均恢复正常（>50%）。TC患者的心电图演变特点为ST段抬高消失、T波倒置出现（在胸前导联V（3）-V（6）以及肢体导联aVL、I和-aVR最为明显）、QTc间期延长（初始为378±60毫秒，随访为470±72毫秒，P<0.05）以及胸前导联R波重现。总之，TC患者常表现为前壁ST段抬高，无法可靠地与急性LAD闭塞相区分。在TC中，肌钙蛋白释放极少、心脏磁共振成像未见延迟强化（大多数患者）以及LVEF恢复正常，这些表现均符合显著心肌顿抑的存在。进行性T波倒置、QTc间期延长和R波重现的心电图演变可能是这种情况下潜在心肌顿抑的电生理表现。
