[Thyroid hormones during the correction of acquired mitral defects under perfusion-free hypothermia]

Total triiodothyronine and thyroxine were measured in the blood plasma during different stages of surgery and after it in 26 patients operated on the open heart under conditions of hypothermia without perfusion. Cooling without perfusion did not appreciably affect the levels of thyroid hormones. Only their ratio was evidently changed at cooling below 30 degrees C with the predominant content of thyroxine. After surgery functional hypothyrosis developed. The shifts were the most expressed on day 3 after the operation. Thyroid status normalized by day 10 postoperation.