title: Decreased aorto-septal angle may contribute to left ventricular diastolic dysfunction in healthy subjects.
abstract: BACKGROUND
  Left ventricular (LV) diastolic dysfunction is often observed in healthy older subjects without structural heart disease, although its exact mechanisms have not been established. A decrease in the aorto-septal angle (ASA), an alteration of LV shape due to aortic elongation, is also frequently seen in elderly subjects. The objective of this study was to evaluate whether it can contribute to LV diastolic dysfunction in healthy subjects.
  
  
  METHODS
  Echocardiography was performed in 77 healthy subjects (42 men, mean age 43.2 ± 13.8 years) to measure the ASA, early diastolic transmitral flow velocity (E), isovolumic relaxation time (IRT), and early diastolic mitral annular velocity (e'). The LV peak early diastolic longitudinal strain rate (GSRE ) was measured using a two-dimensional speckle tracking imaging technique.
  
  
  RESULTS
  ASA was significantly correlated with E (r = 0.54, p < 0.001), IRT (r = -0.41, p < 0.001), e' (r = 0.57, p < 0.001), and GSRE (r = 0.63, p < 0.001) and shown by stepwise multivariate analysis to be the strongest independent determinant of E, IRT, and GSRE , and one of the independent determinants of e'.
  
  
  CONCLUSIONS
  The alteration of LV shape associated with reduced ASA may be one of the causes of LV diastolic dysfunction independently of age in otherwise healthy subjects.
authors.affiliation: Graduate School of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, 060-0812, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Okada
authors.forename: Taisei
authors.initials: T
authors.lastname: Mikami
authors.forename: Sanae
authors.initials: S
authors.lastname: Kaga
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakabachi
authors.forename: Ayumu
authors.initials: A
authors.lastname: Abe
authors.forename: Shinobu
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishino
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Nishida
authors.forename: Chikara
authors.initials: C
authors.lastname: Shimizu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Iwano
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsutsui
mesh_terms: D000328:Adult; D000367:Age Factors; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D015331:Cohort Studies; D003971:Diastole / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006346:Heart Septum / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012044:Regression Analysis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*
keywords: aging; diastolic function; interventricular septum; left ventricle; myocardial relaxation