title: [Electrocardiogram analysis in high risk population of unexplained sudden death in Yunnan province].
abstract: OBJECTIVE
  The purpose of this study was to analyze the electrocardiographic features of the people living in the area with high incidence of unexplained sudden deaths in Yunnan province.
  
  
  METHODS
  The electrocardiograms of 338 residents from three villages (Dayao, Ninglang, Heqing) with high incidence of unexplained sudden deaths and one control village (Dali) were analyzed [averaged age was (33.4 +/- 11.7) years, 175 men and 163 women].
  
  
  RESULTS
  The incidence of cardiac arrhythmias was similar low in all groups. The left ventricular hypertrophy was observed in 34.6% of residents from Dayao. QTc significantly prolonged in the residents from all 3 high incidence areas compare the control area of Dali [control (386.8 +/- 27.22) ms, Ninglang (428.92 +/- 25.71) ms, Heqing (440.67 +/- 28.03) ms, Dayao (417.7 +/- 24.00) ms, P < 0.05 vs. control]. Incidence of U wave was significantly higher in Heqing village than that in control village (P < 0.05). The QUc of these 3 villages was: (613.67 +/- 37.34) ms, (597.19 +/- 46.47) ms, (608.59 +/- 39.59) ms respectively, and also significantly longer than the control village of Dali (589.33 +/- 41.27) ms (P < 0.05). The typical pattern of U wave presents as enlarged U wave and apparent T-U complex. In the 7 residents who have the family history of unexplained sudden death, 6 residents have U wave, and 4 of them present typical U wave pattern.
  
  
  CONCLUSIONS
  The significant ECG changes in villages with high incidence of unexplained sudden death in Yunnan province were prolonged QTc, enlarged U wave and apparent T-U complex and these ECG features suggested the repolarization abnormalities of the heart in these subjects.
authors.affiliation: Cardiac Arrhythmia Center, Fu Wai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100037, China.
authors.forename: Li
authors.initials: L
authors.lastname: Feng
authors.forename: Jin-ma
authors.initials: JM
authors.lastname: Ren
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Yue-jin
authors.initials: YJ
authors.lastname: Yang
authors.forename: Wen-li
authors.initials: WL
authors.lastname: Huang
authors.forename: Chong-fu
authors.initials: CF
authors.lastname: Yang
authors.forename: Shao-dong
authors.initials: SD
authors.lastname: Ye
authors.forename: Chong-jian
authors.initials: CJ
authors.lastname: Li
authors.forename: Meng-yue
authors.initials: MY
authors.lastname: Yu
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Ren
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
authors.forename: Tong
authors.initials: T
authors.lastname: Luo
authors.forename: Jian-Song
authors.initials: JS
authors.lastname: Yuan
authors.forename: Bei-xiang
authors.initials: BX
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Gong
authors.forename: Si-yong
authors.initials: SY
authors.lastname: Teng
authors.forename: Dong-feng
authors.initials: DF
authors.lastname: Gu
authors.forename: Guang
authors.initials: G
authors.lastname: Zeng
authors.forename: Jie-lin
authors.initials: JL
authors.lastname: Pu
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China / Q000453:epidemiology; D003645:Death, Sudden / Q000453:epidemiology* / Q000209:etiology; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000503:physiopathology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D055815:Young Adult