[Electrocardiogram analysis in high risk population of unexplained sudden death in Yunnan province].
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.
Feng
Li
L
Cardiac Arrhythmia Center, Fu Wai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100037, China.
Ren
Jin-ma
JM
Zhang
Jian
J
Yang
Yue-jin
YJ
Huang
Wen-li
WL
Yang
Chong-fu
CF
Ye
Shao-dong
SD
Li
Chong-jian
CJ
Yu
Meng-yue
MY
Ren
Xiao-qing
XQ
Gao
Xin
X
Luo
Tong
T
Yuan
Jian-Song
JS
Li
Bei-xiang
BX
Yang
Lin
L
Gong
Jing
J
Teng
Si-yong
SY
Gu
Dong-feng
DF
Zeng
Guang
G
Pu
Jie-lin
JL
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