Postsystolic Shortening by Myocardial Deformation Imaging as a Sign of Cardiac Adaptation to Pressure Overload in Fetal Growth Restriction

Abstract

Fetal growth restriction (FGR) because of placental insufficiency affects 5% to 7% of pregnancies and represents one of the leading causes of perinatal morbidity and mortality.1 Numerous historical cohort studies 2 and animal models 3 have demonstrated that FGR has a strong association not only with metabolic but also with primary cardiovascular remodeling that lead to long-term adverse consequences in later life. The rapid cell proliferation and differentiation during fetal growth are sensitive to any of the even smallest changes damaging the environment that can lead to permanent alterations in structural and functional constitution, which may persist into the adult life. 2 The heart is a central organ in the prenatal adaptation to placental insufficiency and fetal hypoxia. Previous studies have demonstrated remodeled hearts (more globular) with signs of systolic and diastolic dysfunction and preserved ejection fraction. [4][5][6] FGR cases are associated with prenatal adverse cardiac remodeling 4,5 that persists postnatally, 6 and low birth weight was linked to increased cardiovascular mortality in adulthood.2 Chronic pressure/volume overload together with hypoxia in utero have been postulated as the potential underlying mechanistic pathway of prenatal cardiovascular remodeling in FGR. 5,6 Editorial see p 759 Clinical Perspective on p 787Although evaluation of cardiac function with echocardiography has traditionally been limited to volume-based assessment, recent developments in cardiac ultrasound allow the noninvasive measurement of cardiac deformation with direct assessment of myocardial muscle by assessing regional Background-Fetal growth restriction (FGR) is associated with global adverse cardiac remodeling in utero and increased cardiovascular mortality in adulthood. Prenatal myocardial deformation has not been evaluated in FGR to date. We aimed to evaluate prenatal cardiac remodeling comprehensively in FGR including myocardial deformation imaging. Methods and Results-Echocardiography was performed in 37 consecutive FGR (defined as birthweight <10th centile) and 37 normally grown fetuses. A comprehensive fetal echocardiography was performed including tissue Doppler and 2-dimensional-derived strain and strain rate. Postnatal blood pressure measurement at 6 months of age was also performed. FGR cases showed signs of more globular hearts with decreased longitudinal motion (left systolic annular peak velocity: controls mean 6 cm/s [SD myocardial strain and strain rate. [7][8][9] Strain is defined as change in length/thickness of a segment of myocardium relative to its resting length and is expressed as a percentage; strain rate is the velocity of this deformation.7-9 Myocardial deformation imaging has demonstrated a high sensitivity for detecting preclinical myocardial dysfunction in various pathological conditions characterized by myocardial dysfunction, despite preserved ejection fraction, such as asymptomatic carriers of hypertrophic cardiomyopathy, sarcomeric mutations, Fabry disease, or myocardial ste...

Persistence of Cardiac Remodeling in Preadolescents With Fetal Growth Restriction

“…The shape alteration might not have an important influence on the wall stresses at rest, but we think it would alter the response to a pressure challenge. The results of the present study are in line with previous studies demonstrating more globular hearts with impaired longitudinal motion and relaxation in FGR fetuses, 5,19 infants, 20 and children. 3 Our data are also partially in agreement with recent reports in late childhood, 8,21 adolescence, 9 and youth, 10,11 suggesting smaller cardiovascular dimensions and mass with preserved cardiac function (assessed by 2D and Doppler) in FGR.…”

Two‐Dimensional Speckle Tracking of the Fetal Heart

“…[44][45][46][47][48][49][50][51][52][53][54][55][56] Figure 14. Transverse and longitudinal strain using the 17-segment model.…”

“…Deformation analysis has been evaluated in fetuses with twin-twin transfusion syndrome, intrauterine growth restriction, maternal diabetes, as well as other fetal conditions. [44][45][46][47][48][49][50][51][52][53][54][55][56] The problem with its adaptation by the ultrasound community of noncardiologists is that the software used for analysis was initially only available on dedicated cardiovascular ultrasound machines that were not generally available to the broader medical community (Table 1). With changes in imaging technology and the availability of machine-independent software, it is now possible to obtain DICOM clips from virtually any ultrasound machine used for fetal imaging and to analyze deformation of the fetal heart with machine-independent software (Table 1).…”

Fetal Postsystolic Shortening Assessment by Myocardial Deformation Imaging

“…In this issue of Circulation: Cardiovascular Imaging, Crispi et al 4 suggest that postsystolic shortening, as defined by noninvasive strain imaging, is a sign of cardiac adaptation to pressure overload in FGR. A clinical distinction between true FGR from constitutional small-for-gestational age with a near-normal perinatal outcome remains the main iterance of many articles that have been published by this research group.…”

“…In the study by Crispi et al, 4 FGR was defined as birth weight below 10th percentile, without differentiating between early-and late-onset FGR. Strain and strain rate were determined using both Doppler tissue imaging and 2D speckle-tracking echocardiography techniques.…”