Normal reference values of diastolic strain rate in healthy individuals: Chronological trends and the comparison according to genders

Abstract

PURPOSE: Recently, the diastolic strain rate (DSR) utilizing speckle-tracking echocardiography has been proposed as a novel parameter for left ventricular diastolic function. We aimed to present normal reference data for those in a large-sized, selected group of healthy individuals. METHODS: The current study was a part of the Normal echOcardiogRaphic Measurements in KoreAn popuLation (NORMAL), a prospective nationwide survey from 23 centers in Korea. We analyzed 447 subjects (age 48 +/- 15 years, 234 females) without any history of cardiovascular disease and presented the early and late DSRs (SRe and SRa , respectively) in a total and gender-/age-specified groups. RESULTS: Among the total subjects, the mean SRe and SRa were 1.6 +/- 0.4 S(-1) and 0.8 +/- 0.3 S(-1) , respectively. With increasing age, there were significant trends of decreasing SRe and increasing SRa . Although both gender groups showed comparable age, the female group presented significantly higher SRe compared to male subjects with age of 20-59 years, which diminished after the age of 60 years. However, the SRa was comparable between genders in all age groups. On multiple linear regression, age showed independent associations with both SRe (beta = -0.132, P = .010) and SRa (beta = 0.440, P < .001), whereas gender did not show any association with SRe or SRa. CONCLUSION: We present normal reference data of a novel parameter, DSR, in a large-sized selected group with healthy Korean subjects. Additionally, we present significant age-related changes both in SRe and SRa without the impact of their gender.