Assessment Of Fetal Cardiac Function Research Articles

OP06.06: Assessment of fetal cardiac function in monochorionic diamniotic twin pregnancy by myocardial performance index

OP06.06: Assessment of fetal cardiac function in monochorionic diamniotic twin pregnancy by myocardial performance index

OP08.08: Speckle tracking imaging: a new 2D tool for the assessment of fetal cardiac function

OP08.08: Speckle tracking imaging: a new 2D tool for the assessment of fetal cardiac function

Prospective Assessment of Fetal Cardiac Function With Speckle Tracking in Healthy Fetuses and Recipient Fetuses of Twin-to-Twin Transfusion Syndrome

The aim of this study was to assess speckle tracking-derived fetal cardiac function in a normal population and in recipient fetuses of twin-to-twin transfusion syndrome (TTTS). A case-control study was conducted of 59 uncomplicated singleton pregnancies and 17 recipient fetuses of TTTS. Peak systolic strain, strain rate, velocity, and displacement were calculated, corrected for gestational age, and compared between patients with TTTS and controls. The feasibility of speckle tracking was 83% in controls but only 61% in patients with TTTS. Myocardial velocity and displacement increased over gestation, and regional differences were present within each wall and between walls. Strain and strain rate were stable within each wall but were higher in the right ventricle than in the left ventricle and septum. Right ventricular strain was decreased in patients with TTTS compared with controls (0.75+/-0.34 vs 1.00+/-0.37 multiples of the median, P=.04). The feasibility of speckle tracking is low when imaging conditions are challenging, but it can identify right ventricular failure in selected patients with TTTS.

Methods for prenatal assessment of fetal cardiac function

Fetal cardiac function is increasingly recognized as a marker of disease severity and prognosis in selected fetal conditions. Magnetic resonance imaging (MRI) has been used in experimental (animal) fetal cardiology but the lack of a noninvasive fetal electrocardiogram (ECG) to trigger image acquisition remains a major limiting factor precluding its application in humans. Fetal medicine specialists are therefore limited to ultrasound to evaluate human fetal cardiac function. In this review, we aim to provide a complete overview of the different ultrasound techniques that can be used for fetal cardiac function assessment and we discuss their (theoretical) strengths and shortcomings. Conventional methods include M-mode assessment of ventricular contractility and Doppler assessment of the precordial veins and cardiac output (CO). More recent techniques such as the measurement of the myocardial performance index (MPI), myocardial motion analysis with tissue Doppler, speckle tracking and three-dimensional (3D) ultrasound techniques are also discussed.

OC06.04: Regional fetal cardiac function assessment with speckle tracking derived strain measurements

OC06.04: Regional fetal cardiac function assessment with speckle tracking derived strain measurements

Assessment of fetal cardiac function before and after therapy for twin-to-twin transfusion syndrome

We sought to assess fetal cardiac function in monochorionic twins before and after therapy for twin-to-twin transfusion syndrome (TTTS) and compare it with control subjects. We conducted prospective longitudinal assessment of fetal cardiac function in cases undergoing curative fetal therapy for TTTS (n = 39) until 4 weeks postoperatively and in uncomplicated monochorionic twins (n = 23). Fetal cardiac function was assessed by the left and right ventricular myocardial performance index, atrioventricular valve flow pattern, ductus venosus a-wave, and umbilical vein pulsations. Nomograms for the myocardial performance index were constructed. Fetal cardiac function was grossly abnormal in recipient twins of TTTS when compared with control subjects (P < .001 for all indices) but normalized by 4 weeks postoperatively. The donor developed abnormal ductus venosus flow and tricuspid regurgitation postoperatively that regressed within 4 weeks. The cardiac dysfunction in the recipient twin of TTTS normalizes within 1 month after laser. The donor develops a transient impairment of cardiac function postoperatively.

Global Longitudinal Cardiac Strain and Strain Rate for Assessment of Fetal Cardiac Function: Novel Experience with Velocity Vector Imaging

Cardiac strain and strain rate are new methods to quantitate fetal cardiac function. Doppler-based techniques are regional measurements limited by angle of insonation. Newer feature-tracking algorithms permit angle independent measurements from two-dimensional datasets. This report describes the novel measurement of global strain, strain rate, and velocity using Velocity Vector Imaging (VVI) in a group of fetuses with and without heart disease. Global and segmental longitudinal measurements were performed on the right and left ventricles in 33 normal fetuses and 15 fetuses with heart disease. Segmental measurements were compared to global measurements. Clinical outcome data were recorded for fetuses with heart disease. Forty-eight fetuses were evaluated with VVI. Cardiac strain and strain rate in normal fetuses were similar to normal adult values, but lower than pediatric values (LV strain = -17.7%, strain rate -2.4/sec; RV strain = -18.0%, strain rate -1.9/sec). No difference was present between segmental and global measurements of cardiac strain and strain rate, although basal and apical velocities were significantly different from global velocities for both right and left ventricles. In fetuses with heart disease, lower global cardiac strain appeared to correlate with clinical status, although there was no correlation with visual estimates of cardiac function or outcome. Measurement of global longitudinal cardiac strain and strain rate is possible in fetuses using VVI. Segmental measurements are not significantly different from global measurements; global measurements may be a useful tool to quantitate fetal cardiac function.

Validation of the fetal myocardial performance index in the second and third trimesters of gestation

To test the validity of the myocardial performance index (MPI) and its components against the more conventional methods of fetal cardiac function assessment: the ejection fraction (EF) for systolic function and the E/A index (ratio of transmitral flow during early (E) ventricular filling to flow during atrial (A) contraction) for diastolic function, both in a normal population and in a population at risk for cardiac failure because of volume overload (recipient fetuses in cases of twin-twin transfusion syndrome (TTTS)). The MPI was measured prospectively in addition to more commonly used indices of systolic (EF) and diastolic (E/A index) cardiac function in 117 healthy fetuses (gestational age range, 20-36 weeks) and in 14 fetuses suspected of cardiac failure because of the presence of TTTS. Nomograms were constructed for all variables, and correlations between the MPI, EF and E/A index were assessed. The time taken to obtain the measurements as well as the interobserver and intraobserver variability were determined for the MPI and EF. In healthy fetuses, the MPI and EF were independent of gestational age, whereas the E/A index and isovolumetric relaxation time (IRT) increased with gestational age. The MPI correlated inversely with the EF (P<0.001). The IRT showed a trend towards an inverse correlation with the E/A index (P=0.10). The mean+/-SD time needed to measure the MPI and EF was 140+/-65 s and 185+/-187 s, respectively (P=0.43). Interobserver and intraobserver intraclass correlation coefficients for the MPI were 0.98 (95% CI, 0.85-0.99) and 0.82 (95% CI, 0.14-0.95), respectively; those for the EF were 0.58 (95% CI, -0.16 to 0.85) and 0.51 (95% CI, -0.46 to 0.83), respectively; and those for the E/A index were 0.97 (95% CI, 0.88-0.99) and 0.91 (95% CI, 0.66-0.98), respectively. All variables, except ejection time, were significantly different between normal fetuses and those with TTTS. The MPI is an indicator of the systolic component of fetal left ventricular function that can be easily acquired and reproduced. The MPI is strongly correlated with the EF but shows less interobserver and intraobserver variability.

Comparison between pulsed‐wave Doppler‐ and tissue Doppler‐derived Tei indices in fetuses with and without congenital heart disease

The aim of this study was to compare the right (RV) and left (LV) ventricular Tei indices obtained by pulsed-wave Doppler (PD) and tissue Doppler (TD) methods in fetuses with structurally normal and abnormal hearts. This was a retrospective cross-sectional study of 147 fetuses that had a fetal echocardiogram and Tei index measured during a 2-year period. The RV and LV Tei indices were measured using both PD and TD methods. The difference between the two methods of Tei index measurement was tested using paired sample t-test, Pearson correlation coefficient was used to examine their relationship, and the agreement between the methods was tested using Bland-Altman analysis. A total of 87 fetuses had normal hearts and 60 had a congenital heart defect. Both PD and TD Tei indices were measured successfully from at least one ventricle in 123 cases and from both ventricles in 110 cases. The mean TD Tei index was significantly higher than the mean PD Tei index for both ventricles (P < 0.0001). There was a weak but statistically significant correlation between the PD and TD Tei indices of the right ventricle (r = 0.20, P = 0.029), whereas the PD and TD Tei indices of the left ventricle did not correlate significantly (r = 0.04, P = 0.684). When pairs of Tei indices measured by two different methods (123 pairs for the right ventricle and 111 for the left ventricle) were tested with Bland-Altman analysis, the bias and precision were 0.147 and 0.254, respectively, for the right ventricle, and 0.299 and 0.276, respectively, for the left ventricle. Correlation between Tei indices measured by PD and TD methods is weak and the agreement between individual measurements is poor. Therefore, they should not be used interchangeably in the assessment of fetal cardiac function.

Fetal evaluation with ultrasonic Doppler cardiac isovolumetric contraction time

AbstractThe measurement of isovolumetric contraction time (ICT) has been established as a method to evaluate cardiac function. In the fetus, the ICT is calculated from each valve signal obtained by Doppler cardiogram, noninvasively. Recently, the suitable digital-filter setting dividing fetal Doppler cardiac signal enabled us to detect fetal ICT more accurately. In fetal lamb study with this digital band-pass filter, it has been reported that as fetal acidosis developed, a drastic prolongation of the ICT occurred. A prolongation of ICT in potentially compromised fetuses predicted adverse fetal outcome, probably because acidemia following chronic hypoxemia could affect myocardial contractility in human fetuses. Fetal ICT obtained by Doppler cardiac signal is regarded as a simplified and useful index for clinical use in the assessment of fetal cardiac function.

Strain rate derived from color Doppler myocardial imaging for assessment of fetal cardiac function

Color Doppler myocardial imaging (CDMI) is a new multigated method that allows direct analysis of myocardial motion. It is superior to pulsed-wave tissue Doppler in its ability to generate new and important indices of myocardial function such as strain, strain rate and tissue tracking. The purpose of this study was to assess the feasibility of CDMI in the fetal heart. Three normal fetuses of gestational ages 20 + 1, 28 + 1 and 36 + 0 weeks and a fetus of 20 + 3 weeks with aortic valve atresia were studied. Velocity data were acquired from the apical four-chamber view using a Vivid 7 ultrasound platform with integrated software for CDMI and with frame rates around 200/s. Data were post-processed using dedicated software and with the sample area placed at the subvalvular and middle part of the septum and the ventricular walls. CDMI was feasible in all fetuses. The fetus with aortic valve atresia had severely reduced strain rate of the left ventricular wall. Using this new technique it is possible to obtain information on the global and regional contractility of the fetal heart and thereby gain new insights into the physiology of the fetal cardiovascular system. CDMI is a promising new method for monitoring at-risk fetuses.

Reference charts of gestation-specific tissue Doppler imaging indices of systolic and diastolic functions in the normal fetal heart

Assessment of fetal cardiac function is difficult because of limited accessibility. Tissue Doppler imaging (TDI) is a promising technique in assessing diastolic function in adults. There has been sparseness concerning the use of TDI in assessing fetal cardiac function. The aim of this study was to construct reference charts of TDI indices of systolic and diastolic functions of the normal fetal heart. Ventricular myocardial velocities at the left ventricular (LV) wall, right ventricular (RV) wall, and interventricular septum (IVS) were assessed by TDI in 302 subjects. From 19 to 37 weeks of gestation, peak myocardial velocities during early diastole (Em) increased from 3.3 to 7.2, 3.9 to 8.3, and 3.2 to 5.0 m/s at the LV wall, RV wall, and IVS, respectively. Peak myocardial velocities during atrial contraction (Am) also increased throughout gestation, but the magnitude of increase was smaller (6.3 to 7.9, 7.7 to 10.6, and 5.5 to 5.9 m/s for the LV wall, RV wall, and IVS, respectively). As a consequence, the Em/Am ratio increased from 0.51 to 0.61 at midtrimester to 0.76 to 0.91 at term. Similar to Em, peak myocardial velocities during systole (Sm) also increased by almost 2 times from 18 to 37 weeks of gestation (3.8 to 6.0, 4.2 to 7.6, and 3.3 to 5.6 for the LV wall, RV wall, and IVS, respectively). Reference charts of gestation-specific Em, Am, Em/Am ratio, Sm, and E/Em were constructed accordingly. In midtrimester, fetal diastolic function is predominantly contributed by atrial contraction. As gestation advances, ventricular relaxation becomes increasingly mature. Reference charts for TDI indices were constructed, these will allow identification of fetuses with an abnormal diastolic function.

P296: Assessment of fetal cardiac function. Reference ranges between 23 and 41 weeks

P296: Assessment of fetal cardiac function. Reference ranges between 23 and 41 weeks