Does the right ventricle experiment morphologic and functional changes similarly to the left ventricle during pregnancy?

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.

Transthoracic Echocardiographic Assessment of the Heart in Pregnancy-a position statement on behalf of the British Society of Echocardiography and the United Kingdom Maternal Cardiology Society

Pregnancy is a dynamic process associated with profound hormonally mediated haemodynamic changes which result in structural and functional adaptations in the cardiovascular system. An understanding of the myocardial adaptations is important for echocardiographers and clinicians undertaking or interpreting echocardiograms on pregnant and post-partum women. This guideline, on behalf of the British Society of Echocardiography and United Kingdom Maternal Cardiology Society, reviews the expected echocardiographic findings in normal pregnancy and in different cardiac disease states, as well as echocardiographic signs of decompensation. It aims to lay out a structure for echocardiographic scanning and surveillance during and after pregnancy as well as suggesting practical advice on scanning pregnant women.

Modeling renal autoregulation in a hemodynamic, first-trimester gestational model

The maternal cardiovascular system, led by renal volume regulatory responses, changes during pregnancy to ensure an adequate circulation for fetal development and growth. Circulatory maladjustment predisposes to hypertensive complications during pregnancy. Mathematical models can be used to gain insight in the gestational cardiovascular physiology. In this study, we developed an accurate, robust, and transparent model for renal autoregulation implemented in an existing circulatory gestational model. This renal autoregulation model aims to maintain steady glomerular pressure by the myogenic response, and glomerular filtration rate by tubuloglomerular feedback, both by inducing a change in the radius, and thus resistance, of the afferent arteriole. The modeled response of renal blood flow and the afferent arteriole following blood pressure increase were compared to published observations in rats. With solely the myogenic response, our model had a maximum deviation of 7% in change in renal blood flow and 7% in renal vascular resistance. When both the myogenic response and tubuloglomerular feedback were concurrently activated, the maximum deviation was 7% in change in renal blood flow and 5% in renal vascular resistance. These results show that our model is able to represent renal autoregulatory behavior comparable to empirical data. Further studies should focus on extending the model with other regulatory mechanisms to understand the hemodynamic changes in healthy and complicated pregnancy.

Left ventricular assist device in pregnancy: Case report and review of the literature

Left ventricular assist devices have emerged as a safe and effective therapy for end-stage heart failure patients. However, little is known about the safety of these devices during pregnancy. We describe a 23-year-old woman who received a left ventricular device for nonischemic cardiomyopathy of uncertain origin. She became pregnant approximately 1 year later. With close monitoring of her hemodynamic parameters, she was able to achieve a gestational age of 34 weeks, at which time she delivered a healthy male infant by cesarean delivery. Pregnancies in women with left ventricular assist devices may be successful, but remain medically challenging and complex pregnancies. Close multidisciplinary involvement and frequent assessment of device parameters during pregnancy is warranted.