MYOCARDIAL ISCHEMIA AND HYPERTROPHIC CARDIOMYOPATHY

运动诱发的异常在铊-201核素扫描中 肥厚患者常出现静息状态正常化 心肌病。因为目前还不知道这些异常是否 提示心肌缺血，50例肥厚患者 心肌病患者接受了运动铊核素扫描，在治疗期间 同一周测定心肌乳酸代谢和血流动力学 在起搏压力下。37例可逆性铊患者中 异常，27例(73%)有心肌缺血的代谢证据 与13例正常患者中4例(31%)的比较 铊扫描(p&gt；0.01)。11例患者有明显的空洞扩张。 作为他们唯一的铊异常；他们起搏后的平均左心室 舒张末压明显高于13例患者 铊研究正常(33-/+5vs21+/-10毫米汞，p&gt；0.001)。曾经有过 冠脉造影术显示的收缩间隔区或 心外膜冠状动脉受压与心外膜冠状动脉的存在或分布 铊异常。我们的结论是可逆性的铊异常 运动应激是肥厚性心肌缺血的标志 心肌病，最有可能诊断为相对血流不足 心肌。铊核素扫描期间的明显空洞扩张可能 提示左心室充盈与缺血相关的变化， 舒张压升高和心内膜压迫。

Exercise-induced abnormalities during thallium-201 scintigraphy that normalize at rest frequently occur in patients with hypertrophic cardiomyopathy. Because it is not known whether these abnormalities are indicative of myocardial ischemia, 50 patients with hypertrophic cardiomyopathy underwent exercise thallium scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Of the 37 patients with reversible thallium abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with 4 of 13 patients (31%) with normal thallium scans (p>0.01). Eleven patients had apparent cavity dilatation as their only thallium abnormality; their mean post-pacing left ventricular end-diastolic pressure significantly higher than that of the 13 patients with normal thallium studies (33-/+5 vs 21+/-10 mmHg, p>0.001). There was no correlation between angiographic presence of systolic septal or epicardial coronary artery compression and the presence or distribution of thallium abnormalities. We conclude that reversible thallium abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium. Apparent cavity dilatation during thallium scintigraphy may indicate ischemia-related changes in left ventricular filling, with elevation in diastolic pressures and endocardial compression.