title: [Incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and its clinical significance].
abstract: OBJECTIVE
  To analyze the incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and the clinical significance.
  
  
  METHODS
  Twelve-lead body surface electrocardiogram was taken to measure the heart rates and PR intervals from 4 025 healthy individuals (age range from 6 min after birth to 83 years old) who performed physical examination from Jan, 1993 to Dec, 2012 in the Second Xiangya Hospital, Central South University. Statistics were analyzed by SPSS 16.0.
  
  
  RESULTS
  The total incidence of short PR interval was 19.65% (791/4 025). The age group from birth to 13 years old had a higher incidence than the other age groups (χ2=432, P<0.01). The age groups from 1 month after birth and from 1 month to younger than 1 year-old displayed the highest incidences (43.29% and 44.34%, respectively). The lowest incidences were obtained from the 14-17 year-old, 40-49 year-old and 50-59 year-old groups (0.20%, 0.41%, and 0.33%, respectively). The total incidence of long PR intervals was 3.58% (144/4 025). The 1 year-old group had the highest incidence (6.74%), which decreased with the increase of age. The lowest incidence of long PR intervals occurred in the age group from 14-17 years old, which gradually increased after 50 years old. There were no significant differences in long (short) PR intervals between the gender (P>0.05).
  
  
  CONCLUSIONS
  The incidence of long (short) PR intervals varies in different age groups of healthy people. The incidences of long (short) PR intervals in children before 10 years old are higher than those in adults, especially the short PR intervals, as a result of the heart rate affected by childhood autonomic nervous function and the change in atrial volume with age. Adults have long (short) PR interval should be regularly followed-up to prevent cardiovascular events.
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011;Department of Pediatric Cardiovasology, Children's Medical Center, People's Hospital of Hunan Province, Changsha 410005, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Lin
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Lijia
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Runmei
authors.initials: R
authors.lastname: Zou
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Zhenwu
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Pediatric Cardiovasology, Children's Medical Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D055815:Young Adult