title: Relationship between ambient fine particles and ventricular repolarization changes and heart rate variability of elderly people with heart disease in Beijing, China.
abstract: OBJECTIVE
  To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter (PM2.5) on heart repolarization/depolarization and heart rate variability (HRV).
  
  
  METHODS
  We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week and meteorology.
  
  
  RESULTS
  Significant adverse effects of PM2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM2.5 on subjects with hypertension were larger than on the subjects without hypertension.
  
  
  CONCLUSIONS
  This study showed ambient PM2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM2.5.
authors: Department of Occupational and Environmental Health, School of Public Health, Peking University, Beijing 100191, China.
authors: Mei Mei
authors: MM
authors: Xu
authors: Yu Ping
authors: YP
authors: Jia
authors: Guo Xing
authors: GX
authors: Li
authors: Li Qun
authors: LQ
authors: Liu
authors: Yun Zheng
authors: YZ
authors: Mo
authors: Xiao Bin
authors: XB
authors: Jin
authors: Xiao Chuan
authors: XC
authors: Pan
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000633:toxicity*; D004562:Electrocardiography; D004784:Environmental Monitoring; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010316:Particle Size
chemical_list: D000393:Air Pollutants
keywords: Elderly; Heart rate variability; PM2.5; Panel study; Repolarization