title: Evaluation of the Relationship between Circadian Blood Pressure Variation and Left Atrial Function Using Strain Imaging.
abstract: BACKGROUND
  Non-dippers were reported as showing different left atrial function, compared to dippers, but no study to date investigated the changes in the left atrial function according to the diurnal blood pressure pattern, using tissue Doppler and strain imaging.
  
  
  METHODS
  Forty never treated hypertensive patients between 30 and 80 years of age were enrolled in this study. Patients were classified as non-dippers when, during night time, they had a blood pressure decrease of less than 10%. Strain of the left atrium was measured during late systole, and peak strain rates of the left atrium were measured during systole, early and late diastolic periods.
  
  
  RESULTS
  The left atrial expansion index, left atrial active emptying volume and left atrial active emptying fraction were all significantly increased in non-dippers. They also had increased values of mean peak left atrial strain (dippers = 21.26 ± 4.23% vs. non-dippers = 24.91 ± 5.20%, p = 0.02), strain rate during reservoir (dippers = 1.29 ± 0.23 s(-1) vs. non-dippers =1.52 ± 0.27 s(-1), p = 0.01) and contractile period (dippers = -1.38 ± 0.24 s(-1) vs. non-dippers = -1.68 ± 0.32 s(-1), p < 0.01).
  
  
  CONCLUSIONS
  Strain and strain rate acquired from color Doppler tissue imaging demonstrate exaggerated reservoir and booster pump function in never-treated, non-dipper hypertensive patients. These methods are simple and sensitive for the early detection of subtle changes in the left atrial function.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Chan Seok
authors.initials: CS
authors.lastname: Park
authors.forename: Gun-Hee
authors.initials: GH
authors.lastname: An
authors.forename: Young-Woon
authors.initials: YW
authors.lastname: Kim
authors.forename: Youn-Jung
authors.initials: YJ
authors.lastname: Park
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Cho
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Ihm
authors.forename: Hae-Ok
authors.initials: HO
authors.lastname: Jung
authors.forename: Hee-Yeol
authors.initials: HY
authors.lastname: Kim
authors.forename: Hui-Kyung
authors.initials: HK
authors.lastname: Jeon
authors.forename: Ho-Joong
authors.initials: HJ
authors.lastname: Youn
authors.forename: Jae-Hyung
authors.initials: JH
authors.lastname: Kim