Forfar J C, Muir A L, Sawers S A, Toft A D
N Engl J Med. 1982 Nov 4;307(19):1165-70. doi: 10.1056/NEJM198211043071901.
We assessed the effects of exercise and beta-adrenoceptor blockade on left ventricular ejection fraction (LVEF) measured by radionuclide ventriculography in nine patients with uncomplicated hyperthyroidism. Patients were studied in both the hyperthyroid and euthyroid states. The hyperthyroid state was characterized by a high LVEF at rest but--paradoxically--by a significant fall (P less than 0.01) in LVEF during exercise. At the same workload and at the same heart rate, patients had a restoration of the normal rise in LVEF during exercise when they were euthyroid. The LVEF was greater during exercise (P less than 0.02) when the patients were euthyroid than when they were hyperthyroid. Pretreatment with propranolol caused similar reductions in resting LVEF in the hyperthyroid and euthyroid states; the drug attenuated the rise in LVEF during exercise when the patients were euthyroid, but did not influence the exercise-induced reduction in LVEF in hyperthyroidism. The abnormal left ventricular function observed during exercise in hyperthyroidism suggests a reversible functional cardiomyopathy, independent of beta-adrenoceptor activation, that is presumably a direct effect of an excess in circulating thyroid hormones.
我们评估了运动和β-肾上腺素能受体阻滞剂对9例无并发症的甲状腺功能亢进患者经放射性核素心室造影测量的左心室射血分数（LVEF）的影响。对患者的甲状腺功能亢进状态和甲状腺功能正常状态均进行了研究。甲状腺功能亢进状态的特征是静息时LVEF较高，但矛盾的是，运动期间LVEF显著下降（P<0.01）。在相同的工作量和相同的心率下，患者甲状腺功能正常时运动期间LVEF恢复正常升高。患者甲状腺功能正常时运动期间的LVEF高于甲状腺功能亢进时（P<0.02）。普萘洛尔预处理在甲状腺功能亢进和甲状腺功能正常状态下导致静息LVEF出现类似程度的降低；该药物减弱了患者甲状腺功能正常时运动期间LVEF的升高，但不影响甲状腺功能亢进时运动诱导的LVEF降低。甲状腺功能亢进患者运动期间观察到的左心室功能异常提示存在一种可逆的功能性心肌病，与β-肾上腺素能受体激活无关，推测这是循环甲状腺激素过多的直接作用。
