探讨不同碘营养状态的晚孕期孕妇心电图检查结果及其临床意义。

采用整群随机抽样横断面调查法随机选取2013年4月至2014年4月于辽宁省烟台市2家医院就诊的晚孕期孕妇各600例，共计1 200例为研究对象，纳入研究组。采用同样的方法选择同期在这2家医院体检的非孕期女性各300例，共计600例，纳入对照组。检测研究组孕妇体内碘含量，同时记录心电图异常情况，并与对照组非孕期女性心电图检查结果进行统计学比较。按照碘含量测定结果，将研究组晚孕期孕妇分为碘缺乏亚组(G1亚组)，碘过量亚组(G2亚组)和碘正常亚组(G3亚组)。本研究遵循的程序符合上述2家收集受医院人体试验委员会所制定的伦理学标准，得到该委员会批准，分组征得受试者本人的知情同意，并与之签署临床研究知情同意书。

研究组1 200例晚孕期孕妇中，纳入G1、G2、G3亚组者分别为327，79及794例。3个亚组的晚孕期孕妇的年龄和孕龄等一般临床资料比较，差异均无统计学意义(F＝1.49，2.27；P＝0.23，0.10)。3个亚组晚孕期孕妇的年龄与对照组非孕期女性比较，差异亦无统计学意义(F＝1.27，P＝0.29)。G1、G2及G3亚组晚孕期孕妇心电图正常率分别为38.5%(126/327)，36.7%(29/79)及88.9%(706/794)，对照组非孕期女性心电图正常率为88.5%(531/600)。G1、G2及G3亚组晚孕期孕妇与对照组非孕期女性的心电图正常率比较，差异有统计学意义(χ²＝458.70，P<0.001)。G1和G2亚组晚孕期孕妇的心电图正常率明显低于对照组非孕期女性，且差异均有统计学意义(χ²＝256.00，129.55；P<0.001)；而G3亚组晚孕期孕妇与对照组非孕期女性心电图正常率比较，差异却无统计学意义(χ²＝0.059，P＝0.807)。研究组晚孕期孕妇与对照组非孕期女性的异常心电图比较结果显示，前者窦性心动过缓、窦性心动过速、窦性心律不齐、室性早搏、短P-R间期、ST-T改变、电轴左偏或右偏及传导阻滞等异常心电图发生率，均显著高于后者，差异均有统计学意义(χ²＝11.29，39.52，37.70，15.87，315.79，94.03，10.35，13.94；P<0.05)，其中异常率最高的为短P-R间期；但QRS波群低电压发生率与对照组比较，差异却无统计学意义(χ²＝4.83，P＝0.163)。

晚孕期孕妇体内碘营养状态失衡可能导致异常心电图的发生。

To explore the electrocardiogram results of third trimester pregnant women with different iodine nutritional status and their clinical significances.

From April 2013 to April 2014, a total of 1 200 cases of third trimester pregnant women were randomized selected from the two hospitals in Yantai of Liaoning Province as research group by cross-sectional sampling survey method, and a total of 600 cases of non-pregnant women were selected as control group during the same period in the same two hospitals by the same survey method. The iodine nutritional status of third trimester pregnant women were measured, and the electrocardiogram results of research group and control group were statistically analyzed. According to the levels of iodine, the third trimester pregnant women in research group were divided into the subgroup of iodine deficiency (G1 subgroup), iodine excess (G2 subgroup), and iodine sufficiency (G3 subgroup). The study protocol was approved by the Ethical Review Board of Investigation in Human Being of two hospitals which collected above the subjects of this study. Informed consent was obtained from all participants.

Among the 1 200 cases of third trimester pregnant women, 327 cases were enrolled into G1 subgroup, 79 cases were enrolled into G2 subgroup, and 794 cases were enrolled into G3 subgroup. There were no statistically significant differences among third trimester pregnant women in 3 subgroups of in general clinical data of age and gestational age (F=1.49, 2.27; P=0.23, 0.10). There were no statistically significant difference between third trimester pregnant women in 3 subgroups and non-pregnant women in control group of age (F=1.27, P=0.29). There were statistically significant differences in the ratio of normal electrocardiogram among G1, G2, G3 subgroup and control group (χ²=458.70, P<0.001). The ratio of normal electrocardiogram in G1 subgroup (38.5%, 126/327) and G2 subgroup (36.7%, 29/79) were significantly lower than that in control group (88.5%, 531/600), and both the differences were statistically significant (χ²=256.00, 129.55; P<0.001). While there were no statistical significance between ratio of normal electrocardiogram in G3 subgroup (88.9%, 706/794)and control group (χ²=0.059, P=0.807). There were statistically significant differences in rates of sinus bradycardia, sinus tachycardia, sinus arrhythmia, premature ventricular contractions, short P-R interval, alteration in ST-T, electrocardiogram left/right axis deviation, and block between the third trimester pregnant women in 3 subgroups and non-pregnant women in control group (χ²=11.29, 39.52, 37.70, 15.87, 315.79, 94.03, 10.35, 13.94; P<0.05). The incidence of short P-R interval was the highest in abnormal electrocardiogram. But there were no statistically significant difference in QRS wave group low tension between research group and control group (χ²=4.83, P=0.163).

Imbalance of iodine nutritional status of pregnant women in late pregnancy can lead to abnormal electrocardiogram.