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 (GSR(E)) 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. (C) 2014 Wiley Periodicals, Inc.