Over all variability of mitral annular plane peak systolic velocity and peak global longitudinal strain rate in relation to age, body size, and sex: The HUNT Study.

Asbjørn Støylen,Harald E Mølmen,Håvard Dalen

doi:10.1111/echo.14630

Abstract

Left ventricular (LV) systolic global function can be assessed by peak annular systolic velocity S'. Global longitudinal strain rate (GLSR) is relative LV shortening rate, equivalent to normalizing S' for LV length (S'n ). It has previously been shown that mitral annular plane systolic excursion (MAPSE) and global longitudinal strain (GLS) have similar biological variability, but GLS normalizes for one dimension only, inducing a systematic error, increasing body size dependence. The objective of this study was to compare S' with GLSR in the same way, comparing biological variability and body size dependence. A total of 1266 subjects from the third wave of Nord-Trøndelag Health Study (HUNT), without evidence of heart disease, were examined. Strain rate, S' and wall lengths were measured in the four walls of the two- and four-chamber views. Mean S' was 8.4 (1.4)cm/s, (S'n ) was 0.7 (0.14)s-1 and GLSR 1.02 (0.14)s-1 . All measures declined with age. Normalization of mitral annular velocities for LV length, or the use of GLSR, did not reduce overall biological variability compared with S'. S' did show a weak, positive correlation to BSA, while S'n and GLSR a slightly stronger, negative correlation to BSA. S', S'n , and GLSR have similar biological variability, which is mainly due to age, not body size variation. Normalizing S' for LV length (as in Sn or GLSR) reverses correlation with BSA inducing a systematic error, due to the one-dimensional normalization for one dimension only.

Highlights

Systolic left ventricular (LV) shortening can be assessed by peak mitral annular systolic velocity (S′) by spectral Doppler,[1,2,3] which correlates with ejection fraction (EF) in dilated heart disease,[1] slightly less than mitral annular plane systolic excursion (MAPSE).[4]
Age correlated with BP, in linear regression against age and blood pressure, age had the strongest association with S′, S′ for LV length (S′n), and Global longitudinal strain rate (GLSR) with β of −0.39, −0.245, and −0.25, respectively, Systolic blood pressure (SBP)
As S′ is nearly unchanged with larger heart size, GLSR and S′n will decrease by the larger denominator, as seen by the numerically higher, but negative correlations with BSA

Summary

| INTRODUCTION

Systolic left ventricular (LV) shortening can be assessed by peak mitral annular systolic velocity (S′) by spectral Doppler,[1,2,3] which correlates with EF in dilated heart disease,[1] slightly less than mitral annular plane systolic excursion (MAPSE).[4]. Recent data from the Nord-Trøndelag Health Study (HUNT) have shown that for MAPSE and global longitudinal strain (GLS) normalizing for LV length did not reduce biological variability, normalizing for LV length induced a systematic error, with subsequently increased dependence on body size and sex.[16] The basic measures of S′, wall lengths and GLSR in this material, have all been published previously,[9,17,18] but the normalized values of S′n, and the comparisons of variability and relation to body size are new. The aim of the present study was to ascertain the biological variability of S′ vs the normalized values S′n and GLSR in terms of the relations to age, body size and sex, and to see if the relations were similar to those of MAPSE and GLS

| METHODS

| DISCUSSION

| Limitations

Findings

| CONCLUSION