Gestational changes in left ventricular myocardial contractile function: new insights from two-dimensional speckle tracking echocardiography

Stretch-induced compliance mechanism in pregnancy-induced cardiac hypertrophy and the impact of cardiovascular risk factors

Pressure overload-induced hypertrophy compromises cardiac stretch-induced compliance (SIC) after acute volume overload (AVO). We hypothesized that SIC could be enhanced by physiological hypertrophy induced by pregnancy's chronic volume overload. This study evaluated SIC-cardiac adaptation in pregnant women with or without cardiovascular risk (CVR) factors. Thirty-seven women (1st trimester, 1stT) and a separate group of 31 (3rd trimester, 3rdT) women [healthy or with CVR factors (obesity and/or hypertension and/or with gestational diabetes)] underwent echocardiography determination of left ventricular end-diastolic volume (LVEDV) and E/e' before (T0), immediately after (T1), and 15 min after (T2; SIC) AVO induced by passive leg elevation. Blood samples for NT-proBNP quantification were collected before and after the AVO. Acute leg elevation significantly increased inferior vena cava diameter and stroke volume from T0 to T1 in both 1stT and 3rdT, confirming AVO. LVEDV and E/e' also increased immediately after AVO (T1) in both 1stT and 3rdT. SIC adaptation (T2, 15 min after AVO) significantly decreased E/e' in both trimesters, with additional expansion of LVEDV only in the 1stT. NT-pro-BNP increased slightly after AVO but only in the 1stT. CVR factors, but not parity or age, significantly impacted SIC cardiac adaptation. A distinct functional response to SIC was observed between 1stT and 3rdT, which was influenced by CVR factors. The LV of 3rdT pregnant women was hypertrophied, showing a structural limitation to dilate with AVO, whereas the lower LV filling pressure values suggest increased diastolic compliance.NEW & NOTEWORTHY The sudden increase of volume overload triggers an acute myocardial stretch characterized by an immediate rise in contractility by the Frank-Starling mechanism, followed by a progressive increase known as the slow force response. The present study is the first to characterize echocardiographically the stretch-induced compliance (SIC) mechanism in the context of physiological hypertrophy induced by pregnancy. A distinct functional adaptation to SIC was observed between first and third trimesters, which was influenced by cardiovascular risk factors.

The impact of echocardiographic indexation to evaluate cardiac reverse remodeling throughout pregnancy and postpartum

INTRODUCTION AND OBJECTIVES

Echocardiography guidelines suggest normalizing left ventricular (LV) volumes and mass (LVM) to body size. During pregnancy, continuous weight variation impacts on body surface area (BSA) calculation, limiting the longitudinal analysis of cardiac remodeling (CR) and reverse remodeling (RR) variables. Our aim was to identify the most common indexing methodologies in the literature on pregnant populations through a systematic review; and, to compare four scaling methods: (i) none (absolute values); (ii) indexing to the BSA before pregnancy; (iii) allomeric indexing; and (iv) indexing to BSA measured at the same day of cardiac assessment, using an illustrative example.

METHODS

We performed a systematic review of CR and RR during pregnancy and post-partum, using two databases. We included studies reporting longitudinal echocardiographic analysis of cardiac chamber volumes in humans. We used a prospective cohort study of healthy pregnant women who underwent four echocardiographic evaluations during pregnancy and postpartum, as an illustrative example.

RESULTS

Twenty-seven studies were included, most studies indexed to BSA measured at each evaluation moment (n=21). Within-subjects design was the most reported to analyse longitudinal data (n=17). Indexation to the pre-pregnancy BSA or application of allometric indexes revealed a higher effect than BSA measured at each evaluation and an equal effect to not indexing using within-subjects design. The within-subjects designs also revealed a higher effect size value than the between-subjects design for longitudinal analysis of LVM adaptations during pregnancy and postpartum.

CONCLUSION(S)

This study concludes that indexation methods do not impact the clinical interpretation of longitudinal echocardiographic assessment but highlights the need to harmonize normalization procedures during pregnancy.

A Four-Dimensional Volumetric Quantification of the Left Ventricle in Healthy Pregnant Women in the Third Trimester

BACKGROUND

Hemodynamic load and heart structural remodeling rise during pregnancy because these changes are physiologically necessary. Adaptations in the mother's circulatory system may either initiate or aggravate the development of cardiovascular disease in the offspring. If the body is unable to adjust to these changes, it may develop heart conditions like cardiomyopathy. There is a lack of third-trimester echocardiographic data on left ventricular (LV) volume and function in healthy Iraqi women. To understand the cardiac alterations that occur during normal pregnancy, a precise tool that evaluates cardiac function is needed. In that regard, the four-dimensional echocardiography (4DE) technique has markedly improved the quality and accuracy of assessing the size and function of the left ventricle.

AIM

The present study aimed to assess LV volume and function in the third trimester of a healthy pregnancy using 4DE and to compare the results of LV assessment using 4DE with those of LV assessment using conventional two-dimensional (2D) echocardiography.

METHODS

The study was conducted on 75 healthy pregnant women (the case group) and 75 non-pregnant women (the control group). The participants attended Al-Fortat Teaching Hospital from April 1, 2022, to May 30, 2023, and had 2D and 4D echocardiographic studies performed on them.

RESULTS

The LV end-diastolic volume (EDV), end-systolic volume (ESV), and cardiac output (CO) were significantly increased in the case group compared to the control group (90.87 ± 18.03 ml vs. 62.64 ± 14.11 ml, P<0.001; 35.59 ± 6.52 ml vs. 22.42 ± 5.82 ml, P<0.001; and 4.87 ± 1.27 vs. 3.35 ± 0.87 L/m, P<0.001, respectively). In contrast, the LV ejection fraction (LVEF) was significantly decreased in the pregnant group compared to the control group (60.37 ± 5.42 % vs. 64.04 ± 4.99 %, P<0.01). Additionally, the study showed significant differences in EDV, ESV, ejection fraction (EF%), and CO (P<0.001) between 2D and 4D echocardiography, according to the Bland Altman test.

CONCLUSION

In healthy pregnant women in their third trimester, there is an increase in the indicators of preload (ventricular volume and CO) and a decrease in EF%. The 4DE provides detailed images and information about cardiac volumes and function, allowing for the early detection of any potential problems that may arise during pregnancy and thus improving the health outcomes of both the mother and the developing fetus.

Cardiovascular risk factors during pregnancy impact the postpartum cardiac and vascular reverse remodeling

Pregnant women with cardiovascular risk (CVR) factors are highly prone to develop cardiovascular disease later in life. Thus, recent guidelines suggest extending the follow-up period to 1 yr after delivery. We aimed to evaluate cardiovascular remodeling during pregnancy and determine which CVR factors and potential biomarkers predict postpartum cardiac and vascular reverse remodeling (RR). Our study included a prospective cohort of 76 healthy and 54 obese and/or hypertensive and/or with gestational diabetes pregnant women who underwent transthoracic echocardiography, pulse-wave velocity (PWV), and blood collection at the 1st trimester (1T) and 3rd trimester (3T) of pregnancy as well as at the 1st/6th/12th mo after delivery. Generalized linear mixed-effects models was used to evaluate the extent of RR and its potential predictors. Pregnant women develop cardiac hypertrophy, as confirmed by a significant increase in left ventricular mass (LVM). Moreover, ventricular filling pressure (E/e') and atrial volume increased significantly during gestation. Significant regression of left ventricular (LV) volume, LVM, and filling pressures was observed as soon as 1 mo postpartum. The LV global longitudinal strain worsened slightly and recovered at 6 mo postpartum. PWV decreased significantly from 1T to 3T and normalized at 1 mo postpartum. We found that arterial hypertension, smoking habits, and obesity were independent predictors of increased LVM during pregnancy and postpartum. High C-reactive protein (CRP) and low ST2/IL33-receptor levels are potential circulatory biomarkers of worse LVM regression. Arterial hypertension, age, and gestational diabetes positively correlated with PWV. Altogether, our findings pinpoint arterial hypertension as a critical risk factor for worse RR and CRP, and ST2/IL33 receptors as potential biomarkers of postpartum hypertrophy reversal.NEW & NOTEWORTHY This study describes the impact of cardiovascular risk factors (CVR) in pregnancy-induced remodeling and postpartum reverse remodeling (up to 1 yr) by applying advanced statistic methods (multivariate generalized linear mixed-effects models) to a prospective cohort of pregnant women. Aiming to extrapolate to pathological conditions, this invaluable "human model" allowed us to demonstrate that arterial hypertension is a critical CVR for worse RR and that ST2/IL33-receptors and CRP are potential biomarkers of postpartum hypertrophy reversal.

A mathematical model of vascular and hemodynamics changes in early and late forms of preeclampsia

Preeclampsia-eclampsia syndrome is a leading cause of maternal mortality. The precise etiology of preeclampsia is still not well-defined and different forms exist, including early and late forms or preeclampsia, which may arise via distinctly different mechanisms. Low-dose aspirin administered at the end of the first trimester in women identified as high risk has been shown to reduce the incidence of early, but not late, preeclampsia; however, current risk factors show only fair predictive capability. There is a pressing need to develop accurate descriptions for the different forms of preeclampsia. This paper presents 1D fluid, solid, growth, and remodeling models for pregnancies complicated with early and late forms of preeclampsia. Simulations affirm a broad set of literature results that early forms of preeclampsia are characterized by elevated uterine artery pulsatility index (UA-PI) and total peripheral resistance (TPR) and lower cardiac output (CO), with modestly increased mean arterial blood pressure (MAP) in the first half of pregnancy, with elevation of TPR and MAP beginning at 20 weeks. Conversely, late forms of preeclampsia are characterized by only slightly elevated UA-PI and normal pre-term TPR, and slightly elevated MAP and CO throughout pregnancy, with increased TPR and MAP beginning after 34 weeks. Results suggest that preexisting arterial stiffness may be elevated in women that develop both early forms and late forms of preeclampsia; however, data that verify these results are lacking in the literature. Pulse wave velocity increases in early- and late-preeclampsia, coincident with increases in blood pressure; however, these increases are mainly due to the strain-stiffening response of larger arteries, rather than arterial remodeling-derived changes in material properties. These simulations affirm that early forms of preeclampsia may be associated with abnormal placentation, whereas late forms may be more closely associated with preexisting maternal cardiovascular factors; simulations also highlight several critical gaps in available data.

Maternal left ventricular function and adverse neonatal outcomes in women with cardiac disease

Purpose

To evaluate the relationship between maternal left ventricular systolic function, utero-placental circulation, and risk of adverse neonatal outcomes in women with cardiac disease.

Methods

119 women managed in the pregnancy heart clinic (2019–2021) were identified. Women were classified by their primary cardiac condition. Adverse neonatal outcomes were: low birth weight (< 2500 g), small-for-gestational-age (< 10th birth-weight centile), pre-term delivery (< 37 weeks’ gestation), and fetal demise (> 20 weeks’ gestation). Parameters of left ventricular systolic function (global longitudinal strain, radial strain, ejection fraction, average S’, and cardiac output) were calculated and pulsatility index was recorded from last growth scan.

Results

Adverse neonatal outcomes occurred in 28 neonates (24%); most frequently in valvular heart disease (n = 8) and cardiomyopathy (n = 7). Small-for-gestational-age neonates were most common in women with cardiomyopathy (p = 0.016). Early pregnancy average S’ (p = 0.03), late pregnancy average S’ (p = 0.02), and late pregnancy cardiac output (p = 0.008) were significantly lower in women with adverse neonatal outcomes than in those with healthy neonates. There was a significant association between neonatal birth-weight centile and global longitudinal strain (p = 0.04) and cardiac output (p = 0.0002) in late pregnancy. Pulsatility index was highest in women with cardiomyopathy (p = 0.007), and correlated with average S’ (p < 0.0001) and global longitudinal strain (p = 0.03) in late pregnancy.

Conclusion

Women with cardiac disease may not tolerate cardiovascular adaptations required during pregnancy to support fetal growth. Adverse neonatal outcomes were associated with reduced left ventricular systolic function and higher pulsatility index. The association between impaired systolic function and reduced fetal growth is supported by insufficient utero-placental circulation.

Usefulness of second trimester left ventricular global longitudinal strain for predicting adverse maternal outcome in pregnant women aged 35 years or older

The present study was primarily designed to accurately determine biventricular and biatrial myocardial function, assessed by two-dimensional speckle tracking echocardiography (2D-STE), in a prospective cohort of pregnant women aged ≥ 35 years, at the second trimester of pregnancy. Secondly, we aimed at investigating the main independent predictors of adverse maternal outcome (AMO) in the same study population. 80 consecutive pregnant women aged ≥ 35 years, 80 gestational week-matched (18.4 ± 1.6 vs 18.5 ± 1.8 weeks, p = 0.71) pregnant women aged < 35 years and 80 non-pregnant women aged ≥ 35 years without any comorbidity were included in this prospective study. All pregnant women underwent obstetric evaluation, modified Haller index (MHI) assessment and a conventional two-dimensional transthoracic echocardiography implemented with complete 2D-STE analysis of both ventricles and atria at the second trimester of pregnancy. AMO was defined as the occurrence of any of the following: gestational hypertension (GH) including preeclampsia; gestational diabetes mellitus (GDM); preterm delivery (PD); emergency caesarean section (ECS); postpartum haemorrhage (PPH); premature rupture of membranes (PROM); maternal death. Compared to younger pregnant women, pregnant women aged ≥ 35 years were more likely to be found with: (1) body mass index (BMI) ≥ 30 kg/m2 (37.5% of total); (2) significantly increased inflammatory markers; (3) significantly greater left ventricular mass index; (4) significantly impaired hemodynamics; (5) significantly reduced bi-atrial and bi-ventricular myocardial strain parameters, despite normal ejection fraction. A strong inverse correlation between second trimester BMI and left ventricular (LV)-global longitudinal strain (GLS) (r =  - 0.84) and between second trimester MHI and LV-GLS (r =  - 0.81) was demonstrated in pregnant women aged ≥ 35 years. GH, GDM, PD, ECS, PPH and PROM were detected in 15%, 12.5%, 10%, 8.7%, 8.7% and 7.5% of women, respectively. Age (OR 2.04, 95% CI 1.46-2.84), second trimester BMI (OR 2.40, 95% CI 1.64-3.51) and second trimester LV-GLS (OR 0.07, 95%C I 0.01-0.34) were independently associated with outcome. Age ≥ 37 years, BMI ≥ 30 kg/m2 and LV-GLS less negative than - 18% were the best cut-off values for predicting AMO. A LV-GLS less negative than - 18% allows to identify, among older pregnant women, those with an increased risk of AMO. Both intrinsic myocardial dysfunction and extrinsic compressive mechanical phenomena might affect global myocardial deformation during gestation.

Difference in cardiac remodeling between female athletes and pregnant women: a case control study

Objectives

The aim of this study was to detect possible differences in reversible cardiac remodeling occurring in sport training and twin pregnancy. Background: cardiac remodeling occurs in athletes and pregnant women due to training and fetal requirements, respectively. These changes could be apparently similar.

Methods

21 female elite athletes (23.2 ± 5.3 years), 25 women with twin pregnancies (35.4 ± 5.7 years) and 25 healthy competitive female athletes (controls), age-matched with pregnant women (34.9 ± 7.9 years), were enrolled. This latter group was included to minimize the effect of age on cardiac remodeling. All women evaluated through anamnestic collection, physical examination, 12 leads ECG, standard echocardiogram and strain analysis. Sphericity (SI) and apical conicity (ACI) indexes were also calculated.

Results

Pregnant women showed higher LA dimension (p < 0.001) compared to both groups of athletes. LV e RV GLS were significantly different in pregnant women compared to female athletes (p = 0.02 and 0.03, respectively). RV GLS was also different between pregnant women and controls (p = 0.02). Pregnant women showed significantly higher S′ wave compared to female athletes (p = 0.02) but not controls. Parameters of diastolic function were significantly higher in athletes (p = 0.08 for IVRT and p < 0.001 for E/A,). SI was lower in athletes in both diastole (p = 0.01) and systole (p < 0.001), while ACIs was lower in pregnant women (p = 0.04).

Conclusions

Cardiac remodeling of athletes and pregnant women could be similar at first sight but different in LV shape and in GLS, highlighting a profound difference in longitudinal deformation between athletes and pregnant women. This difference seems not to be related with age. These findings suggest that an initial maternal cardiovascular maladaptation could occur in the third trimester of twin pregnancies.

Pregnancy Complications Lead to Subclinical Maternal Heart Dysfunction—The Importance and Benefits of Follow-Up Using Speckle Tracking Echocardiography

Pregnancy complications such as gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP) are frequent and influence not only fetal outcomes but also the maternal cardiac function. GDM and HDP may act as a proxy for increased metabolic and cardiovascular risk later in life. Speckle tracking echocardiography (STE) is a relatively new imaging technique that provides more sensitive assessment than conventional echocardiography of the maternal cardiac function. Recent research suggests that STE can be used during pregnancy and postpartum as a useful method of early detection of subclinical maternal cardiac changes related to pregnancy complications, such as GDM and HDP, and as an indicator for future maternal cardiovascular disorders. The aim of this review was to underline the current value of STE in the follow-up protocol of high-risk pregnant women, as a mean for pre- and postpartum monitoring. A review of the literature was conducted in the PubMed database to select relevant articles regarding the association of STE changes and HDP or GDM in the prenatal and postpartum maternal evaluations. Both GDM and HDP are associated with subtle myocardial changes in shape, size and function; these preclinical cardiac changes, often missed by conventional evaluation, can be detected using STE. Left ventricular global circumferential strain might be an important predictor of maternal cardiovascular disorders and might help to define a high-risk group that requires regular monitoring later in life and timely intervention.

A mathematical model of maternal vascular growth and remodeling and changes in maternal hemodynamics in uncomplicated pregnancy

The maternal vasculature undergoes tremendous growth and remodeling (G&R) that enables a > 15-fold increase in blood flow through the uterine vasculature from conception to term. Hemodynamic metrics (e.g., uterine artery pulsatility index, UA-PI) are useful for the prognosis of pregnancy complications; however, improved characterization of the maternal hemodynamics is necessary to improve prognosis. The goal of this paper is to develop a mathematical framework to characterize maternal vascular G&R and hemodynamics in uncomplicated human pregnancies. A validated 1D model of the human vascular tree from the literature was adapted and inlet blood flow waveforms at the ascending aorta at 4 week increments from 0 to 40 weeks of gestation were prescribed. Peripheral resistances of each terminal vessel were adjusted to achieve target flow rates and mean arterial pressure at each gestational age. Vessel growth was governed by wall shear stress (and axial lengthening in uterine vessels), and changes in vessel distensibility were related to vessel growth. Uterine artery velocity waveforms generated from this model closely resembled ultrasound results from the literature. The literature UA-PI values changed significantly across gestation, increasing in the first month of gestation, then dramatically decreasing from 4 to 20 weeks. Our results captured well the time-course of vessel geometry, material properties, and UA-PI. This 1D fluid-G&R model captured the salient hemodynamic features across a broad range of clinical reports and across gestation for uncomplicated human pregnancy. While results capture available data well, this study highlights significant gaps in available data required to better understand vascular remodeling in pregnancy.

Pregnancy related changes in Doppler gradients and left ventricular mechanics in women with sub-valvular or valvular aortic stenosis

BACKGROUND

The aim of our study was to characterize echocardiographic changes during pregnancy in women with known LVOT obstruction or AS compared to the healthy pregnancy controls, and to assess the relationship with pregnancy outcomes.

METHODS

We retrospectively studied 34 pregnant patients with congenital LVOT obstruction or AS with healthy age-matched pregnant controls. Patients with other significant valvular lesions, structural heart disease (LVEF < 40%), or prior valve surgery were excluded. All LVOTO/AS patients underwent a minimum of two consecutive echocardiograms between 1 year pre-conception and 1 year postpartum, with at least two studies during the pregnancy. Comprehensive echocardiographic evaluation was performed including speckle-tracking LV global longitudinal strain.

RESULTS

A total of 83 echocardiograms from the study group and 34 echocardiograms from the control group were evaluated. Over the range of LVOTO/AS, a significantly greater increase in the AV gradients and LV and LA volumes were observed as compared with the controls. In the sub-group of LVOTO/AS pregnant women with ≥ moderate (n = 8) versus < moderate LVOTO/AS (n = 26), averaged 2^nd /3^rd trimester LVEF was lower (51 ± 12)% versus (58 ± 4)%, (p = 0.02) and GLS was lower (-19.5 ± 2.8) versus (21.2 ± 2.4), (p = 0.06). Pregnancy was well tolerated despite these changes.

CONCLUSION

Among pregnant women with even milder forms of LVOTO/AS, increases in cardiac volumes and AV gradients can be expected over the course of pregnancy. Significant decreases in LV function and mechanics were only observed in women with moderate or greater LVOTO/AS, although still remained in normal range.

Chest conformation spuriously influences strain parameters of myocardial contractile function in healthy pregnant women

AIMS

Left ventricular (LV) contractility during noncomplicated pregnancy has been previously investigated by two-dimensional speckle-tracking echocardiography (2D-STE), with conflicting results. Chest abnormalities might affect myocardial strain parameters, yet this issue has not been previously investigated during pregnancy. We evaluated the influence of chest conformation on myocardial strain parameters in healthy pregnant women.

METHODS

Between October 2019 and February 2020, 50 healthy pregnant women (32.3 ± 4.0 years old) were consecutively studied. They underwent obstetric visit, assessment of chest shape by modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) and transthoracic echocardiography implemented with 2D-STE analysis of all myocardial strain parameters in the first trimester (12-14 weeks), third trimester (36-38 weeks) and 6-9 weeks after delivery.

RESULTS

LV ejection fraction remained substantially unchanged (P = 0.13), while on the average all myocardial strain parameters showed a small but significant decrease during pregnancy, and recovered postpartum (all P < 0.001). Women with concave-shaped chest wall (MHI > 2.5, n = 29), and those with normal chest conformation (MHI ≤ 2.5, n = 21) were then separately analyzed. Pregnant women with MHI above 2.5, but not those with MHI 2.5 or less, showed a progressive but reversible decrease in all myocardial strain parameters (all P < 0.001). MHI was strongly correlated with LV global longitudinal strain (r = -0.87) and LV global circumferential strain (r = -0.83) in the third trimester of pregnancy.

CONCLUSION

Myocardial strain impairment during healthy pregnancy may not reflect intrinsic myocardial dysfunction but rather intraventricular dyssynchrony related to a narrow antero-posterior chest diameter and rise in the diaphragm, with consequent extrinsic myocardial compression.

Clinical value of 2D speckle tracking imaging in evaluating the effect of percutaneous intramyocardial septal radiofrequency ablation in patients with hypertrophic obstructive cardiomyopathy

PURPOSE

To explore the short-term changes after percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) in patients with hypertrophic obstructive cardiomyopathy (HOCM), using quantitative analysis of two-dimensional speckle tracking imaging (2D-STI).

METHODS

This prospective self-controlled study included 30 HOCM patients treated with PIMSRA. The study for each patient spanned over at least 1 year. Interventricular septal thickness and the left ventricular outflow tract peak pressure gradient (LVOT-PG) were measured through echocardiography, and 2D-STI was used to evaluate the left ventricular (LV) systolic function and synchrony. Cardiac function was assessed using the New York Heart Association's (NYHA) functional classification for cardiac disease, and through the serum levels of cardiac troponin I (cTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Biomarkers procollagen type I carboxy-terminal propeptide (PICP) and matrix metalloproteinases-2 (MMP-2) were detected for noninvasive assessment of myocardial fibrosis.

RESULTS

The patients' interventricular septal thickness, LVOT-PG, NYHA class, and plasma PICP and MMP-2 levels at the first month postoperatively were significantly lower than before operation (all P < .05). The 2D-STI quantitative variables of LV systolic function and synchrony improved significantly (all P < .05). They improved further 1 year postoperatively (P < .01 or P < .001). Serum cTnI and NT-proBNP levels increased 1 month postoperatively, but significantly decreased 1 year postoperatively (both P < .05). Pearson or Spearman correlation analysis showed that the improvement of interventricular septal thickness, LVOT-PG, NYHA class, and the levels of cTnI, NT-proBNP, PICP and MMP-2, were in positive correlation with the restoration of LV systolic function and synchrony (P < .01 or P < .001).

CONCLUSION

The changes in 2D-STI quantitative variables related to LV systolic function and synchrony are closely correlated with the improvement of cardiac function in HOCM patients after PIMSRA. These 2D-STI variables can serve for objective, accurate, and noninvasive evaluation of the HOCM treatment.

Adaptation of left ventricular diastolic function to pregnancy: a systematic review and meta-analysis

Objective:

To meta-analytically determine the adaptation of left ventricular diastolic function (LVDF)-indices to singleton normotensive pregnancies.

Methods:

Literature was retrieved from PubMed and Embase. We included studies that reported a nonpregnant reference measurement and LVDF indices (mitral inflow signals, left atrial volume and tissue Doppler measurements). Mean differences between pregnant and reference measurements and weighted means of absolute values were calculated using a random-effects model.

Results:

We included 34 eligible studies. Normotensive pregnancies were characterized by an initially larger increase in the passive left ventricular filling (E-wave peak velocity, 13%) compared to active left ventricular filling during diastole (A-wave peak velocity, 6%) resulting in a 16% increase of the E/A ratio in the first trimester. The E/A ratio progressively decreased during advancing gestation to −18% at term, resulting from stabilizing E-wave peak velocity and increased A-wave peak velocity. The E/e′ ratio was increased between 22 and 35 weeks (a maximal increase of 13%) in normotensive pregnancy. Left atrial volume (LAV) progressively increased from 15 weeks onwards with a maximal increase of 30% between 36 and 41 weeks.

Conclusion:

LVDF in normotensive pregnancy was improved in the first trimester after which LVDF progressively worsened. Large-scale studies in normotensive and hypertensive complicated pregnancies are needed for a more precise insight into LVDF changes during pregnancy.

Cardiac Responses to Submaximal Isometric Contraction and Aerobic Exercise in Healthy Pregnancy

PURPOSE

The increased physiological demand of pregnancy results in the profound adaptation of the maternal cardiovascular system, reflected by greater resting cardiac output and left ventricular (LV) deformation. Whether the increased resting demand alters acute cardiac responses to exercise in healthy pregnant women is not well understood.

METHODS

Healthy nonpregnant (n = 18), pregnant (n = 14, 22-26 wk gestation), and postpartum women (n = 13, 12-16 wk postdelivery) underwent assessments of cardiac function and LV mechanics at rest, during a sustained isometric forearm contraction (30% maximum), and during low-intensity (LOW) and moderate-intensity (MOD) dynamic cycling exercise (25% and 50% peak power output). Significant differences (α = 0.05) were determined using ANCOVA and general linear model (resting value included as covariate).

RESULTS

When accounting for higher resting cardiac output in pregnant women, pregnant women had greater cardiac output during isometric contraction (2.0 ± 0.3 L·min-1·m-1.83; nonpregnant, 1.3 ± 0.2 L·min-1·m-1.83; postpartum, 1.5 ± 0.5 L·min-1·m-1.83; P = 0.02) but similar values during dynamic cycling exercise (pregnant, LOW = 2.8 ± 0.4 L·min-1·m-1.83, MOD = 3.4 ± 0.7 L·min-1·m-1.83; nonpregnant, LOW = 2.4 ± 0.3 L·min-1·m-1.83, MOD = 3.0 ± 0.3 L·min-1·m-1.83; postpartum, LOW = 2.3 ± 0.4 L·min-1·m-1.83, MOD = 3.0 ± 0.5 L·min-1·m-1.83; P = 0.96). Basal circumferential strain was higher in pregnant women at rest, during the sustained isometric forearm contraction (-23.5% ± 1.2%; nonpregnant, -14.6% ± 1.4%; P = 0.001), and during dynamic cycling exercise (LOW = -27.0% ± 4.9%, MOD = -27.4% ± 4.6%; nonpregnant, LOW = -15.8% ± 4.5%, MOD = -15.2% ± 6.7%; P = 0.012); however, other parameters of LV mechanics were not different between groups.

CONCLUSION

The results support that the maternal heart can appropriately respond to additional cardiac demand and altered loading experienced during acute isometric and dynamic exercise, although subtle differences in responses to these challenges were observed. In addition, the LV mechanics that underpin global cardiac function are greater in pregnant women during exercise, leading to the speculation that the hormonal milieu of pregnancy influences regional deformation.

Long-Term Postpartum Cardiac Function and Its Association With Preeclampsia

Background

Preeclampsia is a prominent risk factor for long‐term development of cardiovascular disease. Although existing studies report a strong correlation between preeclampsia and heart failure, the underlying mechanisms are poorly understood. One possibility is the glycoprotein growth factor activin A. During pregnancy, elevated activin A levels are associated with impaired cardiac global longitudinal strain at 1 year, but whether these changes persist beyond 1 year is not known. We hypothesized that activin A levels would remain increased more than 1 year after a preeclamptic pregnancy and correlate with impaired cardiac function.

Methods and Results

To test our hypothesis, we performed echocardiograms and measured activin A levels in women approximately 10 years after an uncomplicated pregnancy (n=25) or a pregnancy complicated by preeclampsia (n=21). Compared with women with a previously normal pregnancy, women with preeclampsia had worse global longitudinal strain (−18.3% versus −21.3%, P=0.001), left ventricular posterior wall thickness (0.91 mm versus 0.80 mm, P=0.003), and interventricular septal thickness (0.96 mm versus 0.81 mm, P=0.0002). Women with preeclampsia also had higher levels of activin A (0.52 versus 0.37 ng/mL, P=0.02) and activin/follistatin‐like 3 ratio (0.03 versus 0.02, P=0.04). In a multivariable model, the relationship between activin A levels and worsening global longitudinal strain persisted after adjusting for age at enrollment, mean arterial pressure, race, and body mass index (P=0.003).

Conclusions

Our findings suggest that both activin A levels and global longitudinal strain are elevated 10 years after a pregnancy complicated by preeclampsia. Future studies are needed to better understand the relationship between preeclampsia, activin A, and long‐term cardiac function.

Pregnancy-induced Cardiovascular Pathologies: Importance of Structural Components and Lipids

Pregnancy leads to adaptations for maternal and fetal energy needs. The cardiovascular system bears the brunt of the adaptations as the heart and vessels enable nutrient supply to maternal organs facilitated by the placenta to the fetus. The components of the cardiovascular system are critical in the balance between maternal homeostatic and fetus driven homeorhetic regulation. Since lipids intersect maternal cardiovascular function and fetal needs with growth and in stress, factors affecting lipid deposition and mobilization impact risk outcomes. Here, the cardiovascular components and functional derangements associated with cardiovascular pathology in pregnancy, vis-à-vis lipid deposition, mobilization and maternal and/or cardiac and fetal energy needs are detailed. Most reports on the components and associated pathology in pregnancy, are on derangements affecting the extracellular matrix and epicardial fat, followed by the endothelium, vascular smooth muscle, pericytes and myocytes. Targeted studies on all cardiovascular components and pathological outcomes in pregnancy will enhance targeted interventions.

Left Ventricular Systolic Function in Pregnant Women with Inherited Thrombophilia

Objectives:The impact of the gestational changes on left ventricular contractility is not clearly defined. Our aim was to evaluate the subtle changes of left ventricular systolic function during pregnancy, assessed by new echocardiographic techniques, in a population tested for inherited thrombophilia. Material and methods:Eighty seven consecutive pregnant women, with a mean age of 32±4 years, genetically tested for inherited thrombophilia (22 with thrombophilic mutations and risk of thrombosis and 65 without significant mutations, considered as the control group) were included. All participants had four clinical and echocardiographyc visits: three during pregnancy (one in each trimester) and the forth six months after giving birth. Left ventricular (LV) systolic function was assessed from ejection fraction (EF) by 2D and 3D echocardiography, mitral annular velocities by tissue Doppler, and strain rate by 2D speckle tracking. Outcomes:There were no differences between groups for any of the echo parameters at each of the four visits. Comparing the third visit with the first one, all parameters of LV systolic function had significantly lower values at the end of pregnancy; EF decreased from 58% to 55% (2D echo), from 60% to 56% (3D TomTec), and from 58% to 55% (Auto4DLVQ), with p<0.001 for all three methods. Moreover, strain assessed by speckle traking decreased during pregnancy, with no differences between groups. In addition to this, mitral annular velocities obtained by tissue Doppler assessment decreased during the gestational period, with no differences between groups. At six months after giving birth, all values were normalized. Conclusion:During pregnancy, LV contractility has a slight decrease, with no criteria of systolic dysfunction. Thrombophilic mutations, with correct anticoagulant treatment, has no impact on LV systolic function.

The Reduced Uterine Perfusion Pressure (RUPP) rat model of preeclampsia exhibits impaired systolic function and global longitudinal strain during pregnancy

BACKGROUND

Preeclampsia (PE) is a disorder prevalent in 3-8% of pregnancies, characterized by hypertension, endothelial dysfunction and cardiac dysfunction, including hypertrophy and impaired global longitudinal strain (GLS), which indicates reduced contractility and tissue injury. Despite several clinical studies highlighting impaired cardiac function in these women, the underlying mechanisms have not been studied, in part, due to lack of an appropriate animal model. The Reduced Uterine Perfusion Pressure (RUPP) rat model produces a PE-like phenotype, including adverse cardiac remodeling. However, whether this translates to impaired cardiac function is not known. The aim of this study was to test the hypothesis that placental ischemia in the RUPP rat leads to impaired left ventricular (LV) systolic function and GLS.

STUDY DESIGN

RUPP (n = 10) rats underwent surgery to induce placental ischemia on gestational day (GD) 14. Sham (n = 10) and RUPP rats had indwelling carotid catheters placed on GD 18, and blood pressure and echocardiography measurements were made on GD 19.

RESULTS

The RUPP group exhibited increased mean arterial pressure compared to the Sham group (123 ± 3 vs. 97 ± 2 mmHg, P < 0.01). RUPP hearts exhibited impaired LV ejection fraction (60 ± 2 vs. 78 ± 2%, P < 0.01) and GLS (-17.89 ± 0.5 vs. -26.31 ± 2.7%, P = 0.02), in addition to cardiac hypertrophy (0.97 ± 0.04 vs. 0.91 ± 0.02 g, P = 0.02).

CONCLUSIONS

Cardiac dysfunction and impaired strain are present in RUPP rats during pregnancy. These findings represent an animal model of PE that could be used to understand the mechanisms of cardiac dysfunction in this disease and ultimately, improve or prevent cardiac abnormalities in these patients.

Left ventricular mechanics in late second trimester of healthy pregnancy

OBJECTIVE

To evaluate left ventricular (LV) mechanics in the second trimester of healthy pregnancy and to determine the influence of underpinning hemodynamics (heart rate (HR), preload and afterload) on LV mechanics during gestation.

METHODS

This was a cross-sectional study of 18 non-pregnant, 14 nulliparous pregnant (22-26 weeks' gestation) and 13 primiparous postpartum (12-16 weeks after delivery) 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 speckle-tracking 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

There were no significant differences in LV structure and traditional measurements of systolic and diastolic function between the three groups. Pregnant women, compared with non-pregnant ones, had significantly higher resting longitudinal strain (-22 ± 2% vs -17 ± 3%; P = 0.002) and basal circumferential strain (-23 ± 4% vs -16 ± 2%; P = 0.001). Apical circumferential strain and LV twist and untwist mechanics were similar between the three groups. No statistically significant relationships were observed between LV mechanics and HR, EDV or SBP within the groups.

CONCLUSIONS

Compared to the non-pregnant state, pregnant women in the second trimester of a healthy pregnancy have significantly greater resting systolic function, as assessed by LV longitudinal and circumferential strain. Contrary to previous work, these data show that healthy pregnant women should not exhibit reductions in resting systolic function between 22 and 26 weeks' gestation. The enhanced myocardial contractile function during gestation does not appear to be related to hemodynamic load and could be the result of other physiological adaptations to pregnancy. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Quantitative evaluation of longitudinal strain in layer-specific myocardium during normal pregnancy in China

Background

The myocardial wall of the left ventricle is a complex, multilayered structure and is not homogenous. The aim of this study was to determine longitudinal strain (LS) in the three myocardial layers in normal pregnant women according to gestation proceedings.

Methods

The advanced two-dimensional speckle tracking echocardiography (2D STE) was performed on 62 women during each pregnancy trimester and 6 to 9 weeks after delivery, while 30 age-matched, healthy, nonpregnant women served as controls. LS on endocardial, mid-myocardial and epicardial layers at 18 cardiac segments were measured.

Results

As gestation proceeded, all of layer-specific LS and global LS progressively decreased, which subsequently recovered postpartum (P < 0.05), and the LS gradient between inner and outer myocardium became greater, which reached its maximum in the late pregnancy. Peak systolic LS was the highest at endocardium and the lowest at epicardium, while the highest at the apical level and the lowest at the base (P < 0.05). In the early pregnancy and postpartum, LS at basal level was homogenous, meanwhile layer-specific LS showed significant differences at mid-ventricular and apical level throughout the progress of normal pregnancy (P < 0.05).

Conclusions

Using 2D STE, three-layer assessment of LS can be performed in pregnant women and shall give us new insights into the quantitative analysis of global and regional LV function during pregnancy. Future studies on the detection of pregnancy related heart disease would require these parameters as reference values for each time point of a normal pregnancy.