[Retrospective study on 116 unexpected sudden cardiac deaths in Yunnan, China].
OBJECTIVE
To identify the epidemiological and clinical features of unexpected sudden cardiac deaths (SUD) in Yunnan.


METHODS
Choosing the old SUD cases from Xiangyun, Heqing, Nanjian and Dayao counties and using the standardized verbal autopsy Form, we interviewed the family members of the cases, witnesses and doctors as well as reviewing their medical files to get relative information.


RESULTS
We identified 116 SUDs in 21 villages from 1984 to 2004. The village-specific annually standardized incidence rates were ranged from 0.2/1000 to 8.9/1000 (median = 0.8/1000). 66% and 29% of the SUDs occurred in July and August respectively. The incidence rates of SUD were higher (1.6/1000, chi(2) = 16, P < 0.01) in 10 - 39 year-olds, and higher in females than in males (RR = 1.6, 95% CI: 1.1 - 2.3). Seventy percent of SUD occurred in families having clustering nature and 60% of the additional cases in the family were occurred within 24 hours (median = 20 hours) after the first SUD identified in the family. SUD occurred in 23 families followed the first affected family in a village during the same season. In these 23 families, 61% of the first SUD occurred within 8 days after the first SUD in the first affected family. 68% and 66% of the SUDs did not have any complaints or signs during the last 3 weeks or from 3 weeks to 2 days prior to the onset of the disease. 63% of the SUDs had cardiac symptoms within the last 2 days prior to the onset with major symptoms as dizziness, nausea, faintness, unconsciousness, weakness and palpitation. The median duration from acute onset to death was 2 hours.


CONCLUSIONS
The extreme time-space clustering of SUD in families and in villages suggested that the risk factors occurred in specific time and location. Familial clustered SUD cases had common exposure pattern. Sudden onset of acute cardiac symptoms often followed by sudden death. Epidemiological study on new cases was necessary to identify risk factors and to develop hypothesis for causation. In July 2005, we instituted a special SUD surveillance system for all the affected counties together with 10 counties which had no reported cases.
Shi
Guo-qing
GQ
Chinese Field Epidemiology Training Program, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Zhang
Jian
J
Huang
Wen-li
WL
Yang
Tao
T
Ye
Shao-dong
SD
Sun
Xiao-dong
XD
Li
Zhao-xiang
ZX
Xie
Xiao-hua
XH
Li
Fu-rong
FR
Wang
Yue-bing
YB
Ren
Jin-ma
JM
Fontaine
Robert E
RE
Zeng
Guang
G
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002681:China / Q000453:epidemiology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013029:Space-Time Clustering; D055815:Young Adult