胺碘酮对老年心律失常患者甲状腺功能的影响

目的探讨口服小剂量胺碘酮(AD)对老年心律失常患者甲状腺功能的作用和影响.方法老年冠心病心律失常住院患者56例,均给予负荷量AD(600mg/d),6d后渐减至维持剂量(50～100mg/d);放射免疫法测定甲状腺激素水平.结果服用AD第6天即可见甲状腺激素水平变化,与用药前相比较,总三碘甲状腺原氨酸(TT3)和游离三碘甲状腺原氨酸(FT3)1个月时下降幅度最大,分别由(1.7±0.7)nmol/L、(3.1±1.1)pmol/L下降为(1.4±0.6)nmol/L、(2.3±1.6)pmol/L,下降了17.2%和27.6%(均为P<0.01);促甲状腺激素(TSH)、游离甲状腺激素(FT4)3个月时上升达峰值,由(2.1±1.6)mU/L和(16.2±4.0)pmol/L升为(4.4±4.7)mU/L及(20.7±4.8)pmol/L,分别为118.8%和15.2%(均为P<0.01),总甲状腺素(TT4)于6个月达峰,由(126.3±20.5)nmol/L升为(154.1±32.6)nmol/L(22.0%,P<0.01).监测1年,仅有12例出现TSH异常上升,6例TSH>15.0mU/L者给予左旋甲状腺片后,有4例逐渐恢复正常.结论老年心律失常患者、特别是安装心脏起搏器的老年患者服用AD第6天即可检测到甲状腺激素水平的变化,1～6个月变化最显著,但大多数变化是在正常值范围内.

The effect of oral amiodarone on thyroid function in elderly patients with cardiac arrhythmias

Objective The effect of oral amiodarone on thyroid function was studied in elderly patients with cardiac arrhythmias. Methods Fifty six inpatients were treated with a loading dose of amiodarone(600 mg/d) for 6 days and then given with a maintaining dose of 50 mg or 100 mg daily. The serum thyroid hormone levels were measured by with radioimmunoassay. Results The serum free and total T 3 levels were found to decrease progressively and significantly from the 6th day to the end of 6th month. The reduction of free and total T 3 levels was 27 6% and 17 2%, respectively in the first month. TSH, free and total T 4 levels were found to increase early.They increased significantly and gradually throughout the study. The increments reached their peak values of 118.8%, 15 2% and 22 0%, respectively between the 3rd and 6th month. Only 22 of the 56 cases were found to have abnormal change of thyroid hormones throughout the study. In 9 of the 11 patients with cardiac pacemaker,TSH was elevated abnormally. However, in most of the patients the abnormal change of thyroid hormone levels could recover spontaneously but gradually without any therapy, except in 6 cases with TSH>15 0 mU/L treatment with 20 mg levothyroxine a day was needed. Conclusions The thyroid function of elderly patients, taking low oral dose of aminodarone for cardiac arrhythmias, especially those with cardiac pacemaker was affected early (on the 6th day) and significantly. However, it recovered spontaneously but gradually in most of the cases even with abnormal thyroid hormone levels throughout the study. Therefore, oral low dose amiodarone (in one year) is safe for the elderly patients, but they must be monitored closely in the first 6 months.