Left ventricular mechanics in late second trimester of healthy pregnancy

Abstract

INTRODUCTION: Healthy pregnancy causes significant changes in maternal hemodynamics that lead to structural and functional adaptation of a woman's heart. Reductions in ejection fraction have been reported in healthy pregnancy; however, this measure of cardiac contractile function is over simplistic and insensitive to the underpinning hemodynamic load. Indices of systolic myocardial deformation, such as left ventricular strain and twist ('LV mechanics') may therefore provide a more accurate assessment of cardiac function during gestation. As such, the aim of this study was to evaluate LV mechanics in the second trimester of healthy pregnancy and secondly, to determine the influence of underpinning hemodynamics (heart rate (HR), preload and afterload) on LV mechanics during gestation. METHODS: We conducted a cross-sectional study of non-pregnant (n=18), primiparous pregnant (22-26 weeks gestation; n=14) and postpartum (12-16 weeks after delivery; n=13) women. All pregnant and postpartum women had uncomplicated, singleton gestations. Cardiac structure and function were assessed using echocardiography. LV mechanics, specifically longitudinal strain, circumferential strain and twist/untwist, were measured using speckletracking echocardiography. Differences between groups were identified using ANCOVA, with age, HR, end-diastolic volume (EDV) and systolic blood pressure (SBP) as covariates. Relationships between LV mechanics and hemodynamics were examined using Pearson's correlation. RESULTS: Pregnant women had significantly greater resting longitudinal and basal circumferential strain compared to non-pregnant women (-22±2 vs.

Persistence of abnormal global longitudinal strain in women with peripartum cardiomyopathy

“…Change in strain may be different by trimester, single vs multiple gestations, maternal age, and by other co-morbidities in pregnancy, like diabetes, in which GLS is reduced. 22 Identifying women at risk or predicting the prognosis of established PPCM would be useful in disease management.…”

Comparison between Modelflow® and echocardiography in the determination of cardiac output during and following pregnancy at rest and during exercise

“…The study took place in the Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University between January 2015 and April 2017. The data presented in this manuscript is a secondary analysis of a larger cross-sectional study that investigated cardiovascular responses to physiological challenges during and after pregnancy (Meah et al, 2019). As such, the power calculation for the sample size (n = 10 per group) was calculated to achieve the primary aim of the study.…”

“…Forty-five Caucasian women were included in the analyses (non-pregnant women, n = 18, pregnant women between 22-26 weeks gestation, n = 15, postpartum women 12-16 weeks post-delivery, n = 12). The baseline characteristics of the population are presented in Table 1 and have been published previously (Meah et al, 2019). Based upon self-report, volunteers were healthy non-smokers, free from cardiovascular and/or metabolic diseases and were not taking any medication at the time of inclusion.…”

“…‡ = indicates differences between groups were identified using independent t-tests that were corrected for multiple comparisons using the Bonferroni correction. Some of the presented data has previously been published elsewhere (Meah et al, 2019).…”

“…x ± SD 95% LoA: Intra-observer CV for measurement of ̇ using echocardiography was 3.2% at rest (Meah et al, 2019) and 3.9% during exercise, as presented in Table 2. The CV was markedly greater at rest and during exercise for ̇ estimated by the Modelflow® method.…”