Familial aggregation and heritability of electrocardiographic intervals and heart rate in a rural Chinese population.
BACKGROUND
Estimates of the genetic influences on electrocardiographic (ECG) parameters are inconsistent in previous reports, and no such studies have been performed in China. So we estimated genetic contributions to PR and QRS intervals and the rate-adjusted QT interval (Bazett's QTc) in a Chinese rural population.


METHODS
A total of 2909 subjects from 847 families were enrolled in the current study. Genetic contributions to ECG parameters were estimated in two ways: correlation coefficients among family members (father-mother, parent-offspring, first sibling-other sibling) and the heritability of each of the ECG parameters.


RESULTS
Our results showed significant correlations among family members on theses parameters: the correlation coefficients for PR interval, QRS duration, QTc interval, and HR, between parent-sibling, and sibling-sibling were 0.17 and 0.13, 0.18 and 0.23, 0.22 and 0.28, 0.19 and 0.18, respectively. The heritability for PR interval, QRS duration, QTc interval, and HR were estimated as 0.34, 0.43, 0.40, and 0.34, respectively.


CONCLUSIONS
Genetic factors, together with the environmental and other cofactors contribute no more than 60% to the variance of the ECG intervals, supporting the concept that multiple factors, including gene-gene and gene-environment interactions could influence ECG interval phenotypes, and genetic factors play a major role.
Li
Jianping
J
Peking University First Hospital, Department of Cardiology, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, 8 Xishiku St., Xicheng District, Beijing, China. lijianping@medmail.com.cn
Huo
Yong
Y
Zhang
Yan
Y
Fang
Zhian
Z
Yang
Jianhua
J
Zang
Tonghua
T
Xu
Xiping
X
Xu
Xin
X
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D006339:Heart Rate / Q000235:genetics*; D006801:Humans; D008133:Long QT Syndrome / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012424:Rural Population / Q000706:statistics & numerical data; D017678:Sex Distribution; D055815:Young Adult