[The prevalence and significance of abnormal thyroid hormone metabolism in acute myocardial infarction].

In order to clarify the relationship between thyroid function and left ventricular function in acute myocardial infarction (AMI), 52 patients (63.3 +/- 11.0 years old) admitted to the coronary care unit within 24 hours after the onset were studied. Both FT3 and FT4 levels measured at 48-72 h after the onset (1.66 +/- 0.59 pg/ml, 1.02 +/- 0.37 ng/dl) were significantly lower than those on admission (2.99 +/- 0.76 pg/ml; p < 0.01, 1.14 +/- 0.25 ng/dl; p < 0.05) and controls (3.27 +/- 0.66 pg/ml; p < 0.01, 1.22 +/- 0.23 ng/dl; p < 0.05). The decline of these thyroid hormone levels correlated well with the severity of AMI (Killip's classification), hemodynamic deterioration and liver function (low levels of albumin and cholinesterase). Low thyroid hormone levels were also associated with the elevation of catecholamine and alpha-hANP levels on admission. Low cortisol and impaired renal function were recognized as factors which might prolong the condition of low thyroid hormones. Non-survivors showed significantly lower levels of FT3 and FT4 48 hours after onset, and a lower level of FT4 in aged patients was consistent with a poor prognosis. In conclusion, the measurement of thyroid hormones in AMI is important in evaluating the severity of the condition and waking a prognosis.