title: Normal 2-Dimensional Strain Values of the Left Ventricle: A Substudy of the Normal Echocardiographic Measurements in Korean Population Study.
abstract: BACKGROUND
  It is important to understand the distribution of 2-dimensional strain values in normal population. We performed a multicenter trial to measure normal echocardiographic values in the Korean population.
  
  
  METHODS
  This was a substudy of the Normal echOcardiogRaphic Measurements in KoreAn popuLation (NORMAL) study. Echocardiographic specialists measured frequently used echocardiographic indices in healthy people according to a standardized method at 23 different university hospitals. The strain values were analyzed from digitally stored images.
  
  
  RESULTS
  Of a total of 1003 healthy participants in NORMAL study, 2-dimensional strain values were measured in 501 subjects (265 females, mean age 47 ± 15 years old) with echocardiographic images only by GE echocardiographic machines. Interventricular septal thickness, left ventricular (LV) posterior wall thickness, systolic and diastolic LV dimensions, and LV ejection fraction were 7.5 ± 1.0 mm, 7.4 ± 1.0 mm, 29.9 ± 2.8 mm, 48.9 ± 3.6 mm, and 62 ± 4%, respectively. LV longitudinal systolic strain (LS) values of apical 4-chamber (A4C) view, apical 3-chamber (A3C) view, apical 2-chamber (A2C) view, and LV global LS (LVGLS) were -20.1 ± 2.3, -19.9 ± 2.7, -21.2 ± 2.6, and -20.4 ± 2.2%, respectively. LV longitudinal systolic strain rate (LVLSR) values of the A4C view, A3C view, A2C view, and LV global LSR (LVGLSR) were -1.18 ± 0.18, -1.20 ± 0.21, -1.25 ± 0.21, and -1.21 ± 0.21-s, respectively. Females had lower LVGLS (-21.2 ± 2.2% vs. -19.5 ± 1.9%,p< 0.001) and LVGLSR (-1.25 ± 0.18-svs. -1.17 ± 0.15-s,p< 0.001) values than males.
  
  
  CONCLUSIONS
  We measured LV longitudinal strain and strain rate values in the normal Korean population. Since considerable gender differences were observed, normal echocardiographic cutoff values should be differentially applied based on sex.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Jae-Hyeong
authors.initials: JH
authors.lastname: Park
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chungbuk National University School of Medicine, Cheongju, Korea.
authors.forename: Ju-Hee
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chungbuk National University School of Medicine, Cheongju, Korea.
authors.forename: Sang Yeub
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jin-Oh
authors.initials: JO
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Gil Hospital, Gachon University of Medicine and Science, Incheon, Korea.
authors.forename: Mi-Seung
authors.initials: MS
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, Korea.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hae Ok
authors.initials: HO
authors.lastname: Jung
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jeong Rang
authors.initials: JR
authors.lastname: Park
authors.affiliation: Department of Cardiology, Kyung Hee University School of Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Il Suk
authors.initials: IS
authors.lastname: Sohn
authors.affiliation: Division of Cardiology, Keimyung University Dongsan Medical Center, Daegu, Korea.
authors.forename: Hyungseop
authors.initials: H
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seong-Mi
authors.initials: SM
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Wonkwang University Hospital, Institute of Wonkwang Medical Science, Iksan, Korea.
authors.forename: Nam Jin
authors.initials: NJ
authors.lastname: Yoo
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Cardiovascular Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyung-Kwan
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Seoul National University and Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Goo-Yeong
authors.initials: GY
authors.lastname: Cho
authors.affiliation: Division of Cardiology, Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
authors.forename: Mi-Rae
authors.initials: MR
authors.lastname: Lee
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jin-Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chi Young
authors.initials: CY
authors.lastname: Shim
authors.affiliation: Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Gil Ja
authors.initials: GJ
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Cardiology, Chonnam National University Hospital, Gwangju, Korea.
authors.forename: Kye Hun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Cardiovascular Center, Kyung Hee University Medical Center, Seoul, Korea.
authors.forename: Woo-Shik
authors.initials: WS
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seung Woo
authors.initials: SW
authors.lastname: Park
keywords: Echocardiography; Normal population; Reference value; Strain