O'Gara P T, Bonow R O, Maron B J, Damske B A, Van Lingen A, Bacharach S L, Larson S M, Epstein S E
Cardiology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD 20892.
Circulation. 1987 Dec;76(6):1214-23. doi: 10.1161/01.cir.76.6.1214.
Myocardial ischemia may play a critical role in the symptomatic presentation and natural history of hypertrophic cardiomyopathy (HCM). To assess the relative prevalence and functional significance of myocardial perfusion abnormalities in patients comprising the broad clinical spectrum of HCM, we studied 72 patients (ages 12 to 69 years, mean 40) using thallium-201 emission computed tomography. Imaging was performed immediately after maximal exercise and again after a 3 hr delay. Regional perfusion defects were identified in 41 of the 72 patients (57%). Fixed or only partially reversible defects were evident in 17 patients, 14 of whom (82%) had left ventricular ejection fractions of less than 50% at rest. Twenty-four patients demonstrated perfusion defects during exercise that completely reversed at rest; all had normal or hyperdynamic left ventricular systolic function (ejection fraction greater than or equal to 50%). Perfusion abnormalities were present in all regions of the left ventricle. However, the fixed defects were observed predominantly in segments of the left ventricular wall that were of normal or only mildly increased (15 to 20 mm) thickness; in contrast, a substantial proportion (41%) of the completely reversible defects occurred in areas of moderate-to-marked wall thickness (greater than or equal to 20 mm, p less than .001). Neither a history of chest pain nor its provocation with treadmill exercise was predictive of an abnormal thallium study, since regional perfusion defects were present in 10 of 18 (56%) completely asymptomatic patients, compared with 31 of 54 (58%) symptomatic patients. These data indicate that myocardial perfusion abnormalities occur commonly among patients with HCM. Fixed or only partially reversible defects suggestive of myocardial scar and/or severe ischemia occur primarily in patients with impaired systolic performance. Completely reversible perfusion abnormalities occur predominantly in patients with normal or supranormal left ventricular systolic function. Such dynamic changes in regional thallium activity may reflect an ischemic process that contributes importantly to the clinical manifestations and natural history of HCM.
心肌缺血可能在肥厚型心肌病（HCM）的症状表现和自然病程中起关键作用。为了评估涵盖HCM广泛临床谱的患者中心肌灌注异常的相对患病率及其功能意义，我们使用铊-201发射计算机断层扫描研究了72例患者（年龄12至69岁，平均40岁）。在最大运动量运动后立即进行成像，并在延迟3小时后再次成像。72例患者中有41例（57%）发现有局部灌注缺损。17例患者存在固定或仅部分可逆的缺损，其中14例（82%）静息时左心室射血分数低于50%。24例患者在运动时出现灌注缺损，静息时完全逆转；所有患者左心室收缩功能正常或亢进（射血分数大于或等于50%）。左心室所有区域均存在灌注异常。然而，固定缺损主要见于左心室壁厚度正常或仅轻度增加（15至20毫米）的节段；相比之下，相当一部分（41%）完全可逆的缺损发生在中度至显著增厚（大于或等于20毫米，p<0.001）的区域。胸痛病史或运动平板试验诱发胸痛均不能预测铊扫描异常，因为18例完全无症状患者中有10例（56%）存在局部灌注缺损，而54例有症状患者中有31例（58%）存在局部灌注缺损。这些数据表明，HCM患者中普遍存在心肌灌注异常。提示心肌瘢痕和/或严重缺血的固定或仅部分可逆的缺损主要发生在收缩功能受损的患者中。完全可逆的灌注异常主要发生在左心室收缩功能正常或超常的患者中。局部铊活性的这种动态变化可能反映了一个对HCM的临床表现和自然病程有重要影响的缺血过程。
