甲减中甲状腺激素水平与心脏电生理活动的相关性研究

Study of the relations between Thyroxin level and ECG activities in Hypothyroidism

目的:研究原发性甲状腺功能减退症患者的心电图(ECG)改变,及血清甲状腺激素(TH)水平与心电图改变的相关性,探讨TH对甲减患者心脏电生理活动的影响。方法:对144例原发性甲减患者(甲减组)和163例正常人(正常对照组)进行常规十二导联ECG检查,分别检测心率(HR)、PR间期(PR)、QRS波时限(QRS)、QT间期(QT)、ST段压低幅度、T波等,同时用化学发光法测定血清总三碘甲状腺原氨酸(TT3)、总甲状腺素(TT4)和促甲状腺激素(TSH)水平,对心电图指标和血清TH水平行相关性分析。结果:甲状腺功能减退症中心电图异常率高于正常对照组(χ2=34.557,P=0.000)。TSH、T3及病程判断心电图异常的能力较好,差异有统计学意义(P<0.05)。甲减组心率显著低于正常对照组,PR间期、QRS时间、QT间期较正常对照组显著延长(P<0.01),心率与TSH、T3、T4呈显著正相关。PR间期、QRS时间、QT间期与T3、T4呈显著负相关,与TSH呈显著正相关。ST段压低、T波异常(倒置、低平或双向)与TSH呈显著负相关,与T3、T4呈显著正相关,差异有统计学意义(P<0.05)。结论:甲减组54.2%,正常组14.7%出现心电图异常,甲状腺功能减退症时随病程的延长、TSH的升高、T3的降低心电图会出现异常。原发性甲状腺功能减退症可对患者窦房结起搏产生显著影响,引起心脏自律性改变,并造成明显的心肌缺血损伤。

Objective： To investigate the electrocardiographic changes （ECG） in hypothyroidism,as well as its correlation with serum thyroid hormones and the influence on patient＇s ECG activities. Methods： ECG was evaluated in 144 hypothyroidism patients （hypothyroidism group） and 163 healty person （control group） in this study. ECG parameters,including heart rate（HR）, PR interval （PR）, QRS time （QRS）, QT time （QT）, ST segment depression and T waves were analyzed. Chemiluminescent immunoassay was used to measure the total thyrotropin （TT3）, total thyroxin （TT4） and thyrotropin （TSH）. Related analysis was also made between electrocardiographic parameters and serum thyroid hormones levels. Results： The abnormality of electrocardiogram in hypothyroidism were higher than control group （X^2= 34. 557, P=0. 000）. The analysis of TSH,T3 and the case duration could diagnose the abnormality of electrocardiogram. The differences has significance in statistics （P〈0.05）. HR in hypothyroidism group was significantly lower compared with the control group, PR, QRS and QT in hypothyroidism group were significantly longer than those in the control group （P 〈0.01）. HR was positively correlated with TSH, T3, T4 , PR,QRS and QT were negatively correlated with T3, T4, but positively with TSH. ST segment de-pression and T waves were negatively correlated with TSH, but positively with T3, T4, the differences have significance in statistics （P d0.05）. Conclusions： The electrocardographic abnormality was 54.2% in the hypothyroidism group and 14. 7% in the control group. The abnormality could be diagnosed by the case duration, the increase of TSH and the decrease of T3. Hypothyroidism has predominant effect on pacemaker cells of sinus node in patient, which may result in changes in autorhythmicity and myocardial ischemia.