Left atrial strain predicts cardiovascular response to exercise in young adults with suboptimal blood pressure.

Maryam Alsharqi,Paul Leeson,Fernando Telles,Adam J Lewandowski,Helen Dawes,Jamie Kitt,Wilby Williamson,Cheryl M.J Tan,Charlie Foster,Holger Burchert,Odaro J Huckstep,Afifah Mohamed,Winok Lapidaire

doi:10.1111/echo.15149

Abstract

To investigate the left ventricular response to exercise in young adults with hypertension, and identify whether this response can be predicted from changes in left atrial function at rest. A total of 127 adults aged 18-40years who completed clinical blood pressure assessment and echocardiography phenotyping at rest and during cardiopulmonary exercise testing, were included. Measurements were compared between participants with suboptimal blood pressure ≥120/80mm Hg (n=68) and optimal blood pressure <120/80mm Hg (n=59). Left ventricular systolic function during exercise was obtained from an apical four chamber view, while resting left atrial function was assessed from apical four and two chamber views. Participants with suboptimal blood pressure had higher left ventricular mass (p = 0.031) and reduced mitral E velocity (p = 0.02) at rest but no other cardiac differences. During exercise, their rise in left ventricular ejection fraction was reduced (p = 0.001) and they had higher left ventricular end diastolic and systolic volumes (p = 0.001 and p = 0.001, respectively). Resting cardiac size predicted left ventricular volumes during exercise but only left atrial booster pump function predicted the left ventricular ejection fraction response ( = .29, p = 0.011). This association persisted after adjustment for age, sex, body mass index, and mean arterial pressure. Young adults with suboptimal blood pressure have a reduced left ventricular systolic response to exercise, which can be predicted by their left atrial booster pump function at rest. Echocardiographic measures of left atrial function may provide an early marker of functionally relevant, subclinical, cardiac remodelling in young adults with hypertension.

Highlights

The prevalence of hypertension in young adults is increasing, with at least one in 17 adults below the age of 40 years being hypertensive.[1]
We investigated the differences in left ventricular response to physical exercise between young adults with optimal and suboptimal blood pressure, and whether this response is associated with subclinical resting left atrial remodelling
Our study extends these findings to much younger groups, with lower average levels of blood pressure suggesting this change in exercise response of the left ventricle may be a very early sign of remodelling, likely to be present in a large proportion of the population

Summary

Introduction

The prevalence of hypertension in young adults is increasing, with at least one in 17 adults below the age of 40 years being hypertensive.[1] Blood pressure levels in young adulthood are associated with risk of stroke and cardiovascular disease in later life.[2,3] identification of those who may benefit from intervention early in life is important. Traditional biomarkers used to risk stratify patients for treatment, such as left ventricular hypertrophy, tend to be less sensitive for identification of those at risk at younger ages, due to relatively shorter durations of exposure.[4,5] Left ventricular hypertrophy develops because blood pressure elevation increases afterload and left ventricular wall stress. Gross changes in left ventricular morphology sufficient to reach criteria for the diagnosis of left ventricular hypertrophy are not often observed until severe disease is established.[6,7,8]

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Results

Conclusion