Objective:To explore the clinical value of synchronized 12-lead Holter in the diagnosis of coronary heart disease myocardial ischemia.Methods:A total of 101 patients with coronary heart disease who came to the Affiliated Hospital of Jining Medical College from May 2019 to May 2020 were selected. They all received conventional electrocardiogram(ECG) and synchronized 12-lead Holter examinations. The value of different examination methods in the diagnosis of myocardial ischemia was compared, and the characteristics of myocardial ischemia in patients with different degrees of coronary artery disease were analyzed.Results:The detection rates of synchronized 12-lead Holter for myocardial ischemia in single-vessel coronary artery disease and multi-vessel coronary artery disease were 28.71% (29/101) and 56.44%(57/101), respectively, which were slightly higher than 17.82%(18/101) and 45.54% (46/101) of conventional ECG, but with no statistically significant difference ( P>0.05), the total myocardial ischemia detection rate of synchronized 12-lead Holter was 85.15%(86/101), which was higher than 63.37%(64/101) of conventional ECG ( P<0.05). The mean frequency of myocardial ischemia in coronary heart disease diagnosed by synchronized 12-lead Holter was higher than that of conventional ECG, and the duration and amplitude of ST-segment depression were higher than those in conventional ECG ( P<0.05). The detection rates of lateral and inferior myocardial ischemia on synchronized 12-lead Holter were 16.28%(14/86) and 22.09%(19/86), respectively, which were higher than 0 of conventional ECG. The detection rate of myocardial ischemia in the anterior septum/anterior wall was 61.62%(53/86), which was lower than 100.00% (64/64)of the conventional ECG ( P<0.01). Synchronized 12-lead Holter in the diagnosis of coronary cardiac myocardial ischemia was highly consistent with that by coronary angiography, the Kappa value was 0.648, and the sensitivity, specificity, accuracy and negative predictive value were 93.33%, 81.82%, 92.08% and 60.00%, respectively, which were higher than 54.44%, 63.64%, 55.45%, 14.58% of conventional ECG ( P<0.05). The number of myocardial ischemic attacks in patients with multi-vessel disease of coronary heart disease was more than that of single vessel disease ( P<0.05), the mean frequency of myocardial ischemia was higher than that of single vessel disease, and the duration and amplitude of ST-terminal depression were higher than those of patients with single-vessel disease ( P<0.05). Conclusions:Synchronized 12-lead Holter is more effective than conventional ECG in the diagnosis of myocardial ischemic attack of coronary heart disease, and it is more consistent with coronary angiography. It can clarify the frequency and extent of myocardial ischemic attacks and help identify the location of myocardial ischemia. It can be used as an important basis for screening myocardial ischemia attacks of coronary heart disease.

Objective:To study the iodine nutritional status of pregnant women in the third trimester in the Southwest of Shandong Province, analyze its impact on their cardiac electrical activity, and provide a basis for scientific supplementation of iodine during pregnancy.Methods:From January 2021 to June 2022, a cross-sectional survey was conducted using cluster random sampling method. According to the inclusion and exclusion criteria, 200 pregnant women in the third trimester were selected from 3 tertiary hospitals in three cities in the Southwest of Shandong Province, and were divided into the third trimester group ( n = 600), and 100 non-pregnant women were selected as the control group ( n = 300). The urinary iodine content was detected by arsenic-cerium catalytic spectrophotometry, and the pregnant women in the third trimester group were subdivided into iodine deficiency subgroup [G1 subgroup, median urinary iodine (MUIC) < 150 μg/L] based on the MUIC, iodine excess subgroup (G2 subgroup, MUIC≥500 μg/L) and moderate iodine subgroup (G3 subgroup, 150 μg/L≤MUIC < 500 μg/L). Chemiluminescence immunoassay was used to measure the serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT 4) and free triiodothyronine (FT 3). The cardiac electrical indexes were detected by a 12-lead surface electrocardiogram (ECG) machine. Results:There was no statistically significant difference in urinary iodine levels between pregnant women in the third trimester group and non-pregnant women in the control group among the 3 tertiary hospitals in the Southwest of Shandong Province ( H = 3.63, 3.27, P > 0.05). In the third trimester group, the proportion of pregnant women in the G1, G2 and G3 subgroups was 27.67% (166/600), 6.83% (41/600) and 65.50% (393/600), respectively. There was a statistically significant difference in urinary iodine levels between the subgroups and the control group ( H = 11.56, P < 0.001). The serum FT 3 and FT 4 levels in the G2 subgroup were lower than those in the G1 and G3 subgroups ( P < 0.001), but there was no statistically significant difference in serum TSH levels among the three subgroups ( P > 0.05). The normal rates of ECG in the G1, G2, G3 subgroups, and the control group were 38.55% (64/166), 41.46% (17/41), 92.37% (363/393), and 95.33% (286/300), respectively. The difference between the groups were statistically significant (χ 2 = 461.25, P < 0.001), the normal rate of ECG in the G1 and G2 subgroups was lower than that in the control group ( P < 0.001). Short P-R intervals and ST-T changes were the most common abnormal ECG in the third trimester group. Conclusions:The incidence of iodine deficiency, iodine excess, and other abnormal iodine nutritional status in pregnant women in the third trimester of the Southwest of Shandong Province is relatively high. Short P-R intervals, ST-T changes, and other arrhythmia caused by this are more common. It is necessary to strengthen monitoring of iodine nutritional status and ECG during pregnancy, and adjust intervention strategies such as iodine supplementation in a timely manner.