ABSTRACT
Objective Through studying the relationship between different concentrations of arsenic in drinking water and ECG changes,to investigate the effects of arsenic on human cardiovascular system.Methods During 2008-2013,people that over 20 years old and over 10 years of drinking arsenic water were investigated in 15 villages of Shanxi Province and Inner Mongolia according to the historical data of endemic arsenic poisoning through drinking water,who were divided into control group (＜ 0.01 mg/L),low arsenic group (0.01-＜ 0.05 mg/L),medium arsenic group (0.05-＜ 0.10 mg/L) and high arsenic group (≥0.10 mg/L) according to the concentration of water arsenic.Arsenic concentrations in drinking water samples were detected by the method of hydride generation atomic fluorescence spectrometry.ECG-site inspections were finished to record 12-lead ECG.The effect of different concentrations of arsenic in drinking water on ECG was studied.Results ECG of 1341 people were surveyed,and abnormal rate was 11.56％ (155/1 341),including abnormal rate of control group,low arsenic group,medium arsenic group and high arsenic group which was 5.7％ (9/158),12.85％ (59/459),12.02％ (28/233),and 12.02％ (59/491),respectively.The abnormal rate of control group was lower than that of low arsenic group,medium arsenic group and high arsenic group (x2 =6.141,4.391,5.090,all P ＜ 0.05).ECG changes were characterized by cardiac arrhythmias and ST-T changes.A variety of arrhythmias abnormal rate of control group [0(0/158)] was lower than that of low arsenic group,medium arsenic group and high arsenic group [4.58％ (21/459),3.86％ (9/233),3.46％ (17/491); x2 =7.483,6.247,5.618,all P ＜ 0.05].In addition,there were significant differences among the four groups in the rates of right ventricular enlargement and myocardial ischemia (x2 =9.525,9.848,all P ＜ 0.05).Conclusions ECG changes of the residents in the areas of water-borne-endemic arsenic poisoning are characterized by cardiac arrhythmias and ST-T changes.Water arsenic concentration exceeding 0.01 mg/L could significantly increase the ECG abnormal rate,indicating that arsenic in drinking water has a certain effect on heart tissue.
ABSTRACT
Objectives To evaluate the clinical value of heart rate variability (HRV) analysis in school-age healthy chil-dren with functional ST-T changes in electrocardiogram (ECG). Methods In 143 school-age children (50 cases of functional ST-T changes, 43 cases of myocarditis children with ST-T change, 50 cases of healthy controls without ST-T changes), HRV time domain value was measured in three groups with 24 dynamic electrocardiogram. Results Compared with healthy controls, PNN50, rMSSD and SDSD were decreased while the heart rate, SDNN and SDANN were increased in children with functional ST-T changes (P all<0.05). Meanwhile, compared with children with functional ST-T changes and healthy controls, the heart rate was increased while PNN50, rMSSD, SDSD, SDNN and SDANN were decreased in the myocarditis children with ST-T change (P<0.05). Conclusions The autonomic nervous system of school-age children is not stable. The functional ST-T changes are related with the imbalance between sympathetic and vagus nerve activities. HRV analysis has important diagnostic signifi-cance in the functional ST-T changes.