Systolic myocardial velocity alterations in the growth-restricted fetus with cerebroplacental redistribution

Developmental Differences in Left Ventricular Strain in IUGR vs. Control Children the First Three Months of Life

BACKGROUND

Intrauterine growth restriction (IUGR) may directly affect cardiovascular function in early life. Longitudinal data on left ventricular longitudinal strain (LVLS), a key measure of cardiac function independent of body size, is not available. We hypothesize impaired cardiac function among IUGR newborns and persistence of the impairment until age 3 months.

METHOD

This is a prospective cohort study of consecutive pregnancies where IUGR was identified at 18-38 weeks gestational age (GA) with healthy controls randomly selected at 18-20 weeks GA. Echocardiograms were performed at birth and at age 3-4 months, and then compared.

RESULTS

At birth, mean (SD) LVLS did not differ between the IUGR group [N = 19; - 15.76 (3.12) %] and controls [N = 35; - 15.53 (3.56) %]. The IUGR group demonstrated no significant change in LVLS at age 3-4 months [- 17.80 (3.82) %], while the control group [- 20.91 (3.31) %] showed a significant increase (P < 0.001). Thus, LVLS was lower in the IUGR group at age 3-4 months (P = 0.003).

CONCLUSION

The lack of increase in LVLS may suggest that IUGR has a direct impact on cardiac function as early as during the first months of life. Trial registration Clinical trials.gov Identifier: NCT02583763, registration October 22, 2015. Retrospectively registered September 2014-October 2015, thereafter, registered prospectively.

Automated analysis of fetal cardiac function using color tissue Doppler imaging in second half of normal pregnancy

OBJECTIVES

Color tissue Doppler imaging (cTDI) is a promising tool for the assessment of fetal cardiac function. However, the analysis of myocardial velocity traces is cumbersome and time-consuming, limiting its application in clinical practice. The aim of this study was to evaluate fetal cardiac function during the second half of pregnancy and to develop reference ranges using an automated method to analyze cTDI recordings from a cardiac four-chamber view.

METHODS

This was a cross-sectional study including 201 normal singleton pregnancies between 18 and 42 weeks of gestation. During fetal echocardiography, a four-chamber view of the heart was visualized and cTDI was performed. Regions of interest were positioned at the level of the atrioventricular plane in the left ventricular (LV), right ventricular (RV) and septal walls of the fetal heart, to obtain myocardial velocity traces that were analyzed offline using the automated algorithm. Peak myocardial velocities during atrial contraction (Am), ventricular ejection (Sm) and rapid ventricular filling, i.e. early diastole (Em), as well as the Em/Am ratio, mechanical cardiac time intervals and myocardial performance index (cMPI) were evaluated, and gestational age-specific reference ranges were constructed.

RESULTS

At 18 weeks of gestation, the peak myocardial velocities, presented as fitted mean with 95% CI, were: LV Am, 3.39 (3.09-3.70) cm/s; LV Sm, 1.62 (1.46-1.79) cm/s; LV Em, 1.95 (1.75-2.15) cm/s; septal Am, 3.07 (2.80-3.36) cm/s; septal Sm, 1.93 (1.81-2.06) cm/s; septal Em, 2.57 (2.32-2.84) cm/s; RV Am, 4.89 (4.59-5.20) cm/s; RV Sm, 2.31 (2.16-2.46) cm/s; and RV Em, 2.94 (2.69-3.21) cm/s. At 42 weeks of gestation, the peak myocardial velocities had increased to: LV Am, 4.25 (3.87-4.65) cm/s; LV Sm, 3.53 (3.19-3.89) cm/s; LV Em, 4.55 (4.18-4.94) cm/s; septal Am, 4.49 (4.17-4.82) cm/s; septal Sm, 3.36 (3.17-3.55) cm/s; septal Em, 3.76 (3.51-4.03) cm/s; RV Am, 6.52 (6.09-6.96) cm/s; RV Sm, 4.95 (4.59-5.32) cm/s; and RV Em, 5.42 (4.99-5.88) cm/s. The mechanical cardiac time intervals generally remained more stable throughout the second half of pregnancy, although, with increased gestational age, there was an increase in duration of septal and RV atrial contraction, LV pre-ejection and septal and RV ventricular ejection, while there was a decrease in duration of septal postejection. Regression equations used for the construction of gestational age-specific reference ranges for peak myocardial velocities, Em/Am ratios, mechanical cardiac time intervals and cMPI are presented.

CONCLUSION

Peak myocardial velocities increase with gestational age, while the mechanical time intervals remain more stable throughout the second half of pregnancy. Using an automated method to analyze cTDI-derived myocardial velocity traces, it was possible to construct reference ranges, which could be used in distinguishing between normal and abnormal fetal cardiac function. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Automated analysis of fetal cardiac function using color tissue Doppler imaging

OBJECTIVE

To evaluate the feasibility of automated analysis of fetal myocardial velocity recordings obtained by color tissue Doppler imaging (cTDI).

METHODS

This was a prospective cross-sectional observational study of 107 singleton pregnancies ≥ 41 weeks of gestation. Myocardial velocity recordings were obtained by cTDI in a long-axis four-chamber view of the fetal heart. Regions of interest were placed in the septum and the right (RV) and left (LV) ventricular walls at the level of the atrioventricular plane. Peak myocardial velocities and mechanical cardiac time intervals were measured both manually and by an automated algorithm and agreement between the two methods was evaluated.

RESULTS

In total, 321 myocardial velocity traces were analyzed using each method. It was possible to analyze all velocity traces obtained from the LV, RV and septal walls with the automated algorithm, and myocardial velocities and cardiac mechanical time intervals could be measured in 96% of all traces. The same results were obtained when the algorithm was run repeatedly. The myocardial velocities measured using the automated method correlated significantly with those measured manually. The agreement between methods was not consistent and some cTDI parameters had considerable bias and poor precision.

CONCLUSIONS

Automated analysis of myocardial velocity recordings obtained by cTDI was feasible, suggesting that this technique could simplify and facilitate the use of cTDI in the evaluation of fetal cardiac function, both in research and in clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Measurement of cardiac function by cardiac time intervals, applicability in normal pregnancy and twin-to-twin transfusion syndrome

BACKGROUND

To detect early cardiac deterioration, a simple and stable tool is needed. Measurement of time intervals in a simple 4-chamber view using color-coded tissue Doppler imaging is a relatively new approach to assess fetal cardiac function. The aim of this study was to evaluate the applicability of this modality and to construct reference ranges for cardiac time intervals.

METHODS

We performed a prospective longitudinal cohort study in healthy fetuses. We used linear mixed models to construct age-adjusted reference ranges for shortening time (St) and lengthening time (Lt) in three cardiac regions: global heart and right and left ventricular wall. St and Lt were expressed as percentage of the cardiac cycle. Feasibility and intra- and interobserver variabilities were evaluated. We applied the technique to twin-twin transfusion syndrome (TTTS) recipients before laser therapy to test the diagnostic performance.

RESULTS

A total of 251 recordings were obtained from 54 healthy singletons. St decreased and Lt increased with gestational age in all regions. We found a high feasibility (99.6%) and excellent intra-/interobserver variability for St (0.96/0.94) and Lt (0.99/0.96) of the global heart. Left and right ventricle performance parameters were good. In TTTS recipients, St was prolonged (p < 0.01) and Lt was shortened (p < 0.01) in all regions and the feasibility was excellent (96.6%).

CONCLUSIONS

The assessment of fetal cardiac function by measurement of cardiac time intervals is technically feasible with good reproducibility, even in difficult scanning circumstances such as TTTS. It is possible to discriminate between healthy and compromised fetuses with this technique.

A Potential Diagnostic Approach for Foetal Long-QT Syndrome, Developed and Validated in Children

In patients with Long-QT Syndrome (LQTS), mechanical abnormalities have been described. Recognition of these abnormalities could potentially be used in the diagnosis of LQTS, especially in the foetus where an ECG is not available and DNA-analysis is invasive. We aimed to develop and validate a marker for these mechanical abnormalities in children and to test its feasibility in foetuses as a proof of principle. We measured the myocardial contraction duration using colour Tissue Doppler Imaging (cTDI) in 41 LQTS children and age- and gender-matched controls. Children were chosen to develop and validate the measurement of the myocardial contraction duration, due to the availability of a simultaneously recorded ECG. Feasibility of this measurement in foetuses was tested in an additional pilot study among seven LQTS foetuses and eight controls. LQTS children had a longer myocardial contraction duration compared to controls, while there was no statistical difference in heart rate. Measuring the myocardial contraction duration in children had a high inter- and intra-observer validity and reliably correlated with the QT-interval. There was an area under the curve (AUC) of 0.71, and the optimal cut-off value showed an especially high specificity in diagnosing LQTS. Measuring the myocardial contraction duration was possible in all foetuses and had a high inter- and intra-observer validity (ICC = 0.71 and ICC = 0.88, respectively). LQTS foetuses seemed to have a longer myocardial contraction duration compared to controls. Therefore, a prolonged contraction duration may be a potential marker for the prenatal diagnosis of LQTS in the future. Further studies are required to support the measurement of the myocardial contraction duration as a diagnostic approach for foetal LQTS.

Segmental Myocardial Displacement and Tissue Velocity Analysis of the Right Ventricle in Hypoplastic Left Heart Syndrome Fetuses and Controls Using Color Tissue Doppler Imaging (C-TDI)

Introduction: The long-term outcome of patients with HLHS (hypoplastic left heart syndrome) is mainly determined by right ventricular function. Our study examines, whether there are differences in segmental right ventricular myocardial displacement and tissue velocities of fetuses with HLHS compared to healthy fetuses during gestation. Materials and methods: A prospective study was conducted including 20 fetuses with HLHS and 20 gestational age matched controls. c-TDI (colour tissue Doppler imaging) derived systolic and diastolic velocities as well as myocardial displacement were assessed in three different locations of the right ventricle (RV). A ROI (region of interest) was placed in the basal, middle and apical part of the myocardium. Possible changes of c-TDI indices in the course of pregnancy and between the three different segments were investigated in both groups. Results: HLHS fetuses showed significantly lower e' velocities measured in the basal and middle part of the RV compared to healthy controls (p < 0.05). Basal displacement showed significantly lower values in HLHS fetuses compared to controls. In control fetuses but not in HLHS fetuses there was a significant increase of basal diastolic velocities and displacement in the course of pregnancy. According to myocardial velocities and displacement values there was a significant decrease from the base of the fetal heart to the apex pointed in both groups. Conclusions: An altered right ventricular myocardial function in HLHS fetuses within different myocardial segments could be demonstrated. An apicobasal gradient with higher velocity and displacement values in the basal part of RV myocardium could be found in both groups. The technique may be of value in the prenatal assessment of myocardial function, however its role as a monitoring tool and outcome predictor needs to be defined.

Automated analysis of color tissue Doppler velocity recordings of the fetal myocardium using a new algorithm

Background

Tissue Doppler imaging (TDI) can be used to assess fetal cardiac function and it has been shown to detect changes associated with hypoxia in animal models. However, the analysis is cumbersome and time consuming. The main objective of this study was to evaluate the feasibility of a new algorithm developed for the automated analysis of color TDI velocity recordings of the fetal myocardium. Furthermore, we wanted to assess the effect of different sizes of region of interests (ROI) on the measurement of cardiac cycle time intervals and myocardial velocities at different gestations.

Methods

This study included analysis of 261 TDI velocity traces obtained from 17 fetal echocardiographic examinations performed longitudinally on five pregnant women. Cine-loops of fetal cardiac four chamber view were recorded with color overlay in TDI mode and stored for off-line analysis. ROIs of different sizes were placed at the level of the atrioventricular plane in the septum and in the right and left ventricular walls of the fetal heart. An automated algorithm was then used for the analysis of velocity traces.

Results

Out of the total 261 velocity traces, it was possible to analyze 203 (78 %) traces with the automated algorithm. It was possible to analyze 93 % (81/87) of traces recorded from the right ventricular wall, 82 % (71/87) from the left ventricular wall and 59 % (51/87) from the septum. There was a trend towards decreasing myocardial velocities with increasing ROI length. However, the cardiac cycle time intervals were similar irrespective of which ROI size was used.

Conclusions

An automated analysis of color TDI fetal myocardial velocity traces seems feasible, especially for measuring cardiac cycle time intervals, and has the potential for clinical application.

Assessing Fetal Cardiac Function by Measuring Myocardial Radial Velocity Using the Phased-Tracking Method

OBJECTIVE

This study aimed to assess the cardiac function of healthy and pathological fetuses by measuring radial velocity using phased tracking (PT). Based on phase differences, PT allows the displacement of a specified point to be detected with improved spatial and temporal resolution.

METHODS

PT was used to assess cardiac radial velocity in the basal free wall of the left and right ventricles in 134 healthy fetuses, 10 second-trimester intrauterine growth-restricted (IUGR) fetuses, and 10 recipient twins with twin-to-twin transfusion syndrome (TTTS). Maximum velocities were measured in systole and early diastole.

RESULTS

Maximum radial velocity was successfully measured in 126 healthy fetuses (94%) at gestational ages of 16-40 weeks. Systolic and early diastolic maximum velocities increased with gestational age in both ventricles. As compared with controls, IUGR fetuses had significantly lower early diastolic maximum velocities in the right ventricle, and recipient twins with TTTS had significantly lower systolic and early diastolic maximum velocities in both ventricles.

CONCLUSIONS

PT demonstrated right ventricular diastolic dysfunction in second-trimester IUGR fetuses as well as systolic and diastolic dysfunctions in both ventricles in recipient twins with TTTS. PT could be useful for evaluating fetal cardiac radial function.

Reference values for fetal tissue velocity imaging and a new approach to evaluate fetal myocardial function

OBJECTIVES

Myocardial function can be evaluated using color-coded tissue velocity imaging (TVI) to analyze the longitudinal myocardial velocity profile, and by expressing the motion of the atrioventricular plane during a cardiac cycle as coordinated events in the cardiac state diagram (CSD). The objective of this study was to establish gestational age specific reference values for fetal TVI measurements and to introduce the CSD as a potential aid in fetal myocardial evaluation.

METHODS

TVI recordings from 125 healthy fetuses, at 18 to 42 weeks of gestation, were performed with the transducer perpendicular to the apex to provide a four-chamber view. The myocardial velocity data was extracted from the basal segment of septum as well as the left and right ventricular free wall for subsequent offline analysis.

RESULTS

During a cardiac cycle the longitudinal peak velocities of septum increased with gestational age, as did the peak velocities of the left and right ventricular free wall, except for the peak velocity of post ejection. The duration of rapid filling and atrial contraction increased during pregnancy while the duration of post ejection decreased. The duration of pre ejection and ventricular ejection did not change significantly with gestational age.

CONCLUSION

Evaluating fetal systolic and diastolic performance using TVI together with CSD could contribute to increase the knowledge and understanding of fetal myocardial function and dysfunction. The pre and post ejection phases are the variables most likely to indicate fetuses with abnormal myocardial function.

Value of annular M-mode displacement vs tissue Doppler velocities to assess cardiac function in intrauterine growth restriction

OBJECTIVE

To compare the ability of two different methods for longitudinal annular motion measurement, M-mode and tissue Doppler imaging (TDI), to demonstrate cardiac dysfunction in intrauterine-growth-restricted (IUGR) fetuses.

METHODS

Cardiac longitudinal annular motion in the basal free wall of the left ventricle (mitral annulus), interventricular septum and tricuspid annulus was assessed in 23 early-onset IUGR cases and 43 controls by TDI (annular peak velocities) and M-mode (displacement).

RESULTS

All annular parameters were significantly decreased in the IUGR group with respect to controls using both methods. M-mode showed a trend towards equal performance as classifier between cases and controls, as compared to TDI, mainly in the tricuspid annulus.

CONCLUSIONS

Both M-mode and TDI demonstrate annular motion changes and consequently cardiac dysfunction in IUGR fetuses. M-mode imaging is simpler to perform and could be as sensitive as TDI for detecting subtle changes.

Evaluation of cardiac systolic and diastolic functions in small for gestational age babies during the first months of life: a prospective follow-up study

OBJECTIVE

The purpose of this study was to evaluate the cardiac functions and age-related changes of these functions in full-term small for gestational age infants during the first 3 months of life.

METHODS

Cardiac functions of 20 term small for gestational age and 20 term appropriate for gestational age infants were studied using conventional and tissue Doppler echocardiography on postnatal day 5 and at 1 and 3 months.

RESULTS

Ventricular diameters, ventricular wall thicknesses, and left ventricular mass significantly increased with age in both groups. All these parameters were significantly lower in small for gestational age infants. No differences were detected by conventional echocardiography between the groups in systolic and diastolic functions. Systolic velocity, early diastolic and atrial contraction velocities, and the ratio between early diastolic and atrial contraction velocities determined by tissue Doppler echocardiography increased with age. Systolic velocity was lower in the small for gestational age babies for all myocardial regions on the 5th day. Peak early diastolic velocity was decreased in the small for gestational age babies at the first and second evaluations for all myocardial regions. The ratio between early diastolic and atrial contraction velocities was significantly lower in the small for gestational age babies for the interventricular septum and right ventricle. Significant positive correlations were detected between the Ponderal index and systolic and early diastolic velocities.

CONCLUSION

The present findings suggest that systolic and diastolic function indices including tissue Doppler measures are significantly affected in small for gestational age babies during the first 3 months of life.

Serial assessment of left-ventricular function using tissue Doppler imaging in premature infants within 7 days of life

Although many echocardiographic parameters can assess cardiac function noninvasively in preterm infants, it has not been determined what indices are the best. We assessed left-ventricular performance in 101 very low-birth weight (VLBW) infants using tissue Doppler imaging (TDI) echocardiography. Echocardiographic examinations, including TDI, were performed serially within 7 days of life. Pulsed-Doppler TDI waveforms were recorded at the mitral valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured. Sa and Aa velocities were both decreased significantly from 3 to 12 h and then gradually increased. Ea velocities showed no significant, longitudinal changes, but Ea values in premature groups appeared to be significantly lower than those in mature groups. The ratio of E to Ea (E/Ea) of VLBW infants seemed to be almost stable from birth to day 7, and this also showed no significant differences between different gestational age groups. E/Ea values in infants with patent ductus arteriosus (PDA) appeared to be greater than those in non-PDA infants. Our present findings suggest that TDI assessment in the early neonatal period might be useful in detecting latent systolic/diastolic failure of critically ill preterm infants.

Fetal color-coded tissue Doppler echocardiography: experiences with the "tracking method" in normal fetuses

OBJECTIVE

Ultrasound-based tissue Doppler imaging has opened new perspectives for non-invasive quantification of global, as well as regional, myocardial function. We therefore studied fetal hearts using the "tracking method" in order to assess its feasibility and changes of fetal myocardial velocities throughout gestation.

STUDY DESIGN

In 89 healthy fetuses color-coded tissue Doppler echocardiography (TDE) was prospectively conducted for further offline-analysis of global and regional myocardial function of the basal segment. Maximum tissue velocities at systole (S), in the early filling phase of diastole (E) and during atrial contraction (A) were estimated from three consecutive cardiac cycles.

RESULTS

Within a selected time limit of 15 min, raw data acquisition was possible in 60 of the 89 fetuses (67%). From the stored samples, velocities of S, E and A-wave could be obtained in 76% with good reproducibility for septal and right wall velocities. During gestation all velocities increased but to a greater extent at the right and left ventricular wall compared to the interventricular septum. The A-wave velocity was higher than E-wave velocity in all basal segments. Throughout gestation, the increase in E-wave was higher, resulting in an increase of the E-wave/A-wave ratio.

CONCLUSION

Tissue Doppler echocardiography using the tracking method in fetal hearts is practical during routine clinical examination, but it is time consuming and requires highly experienced observers The knowledge of myocardial velocities in normal pregnancies is essential in detecting pathologies.

Fetal cardiac function: technical considerations and potential research and clinical applications

Fetal echocardiography was initially used to detect structural anomalies but has more recently also been proposed to assess fetal cardiac function. This review summarizes technical issues and limitations in fetal cardiac function evaluation, as well as its potential research and clinical applications. Functional echocardiography has been demonstrated to select high-risk populations and to be associated with outcome in several fetal conditions including intrauterine growth restriction, twin-to-twin transfusion syndrome, maternal diabetes, and congenital diaphragmatic hernia. Fetal heart evaluation is challenging due to the smallness and high heart rate of the fetus and restricted access to the fetus far from the transducer. Due to these limitations and differences in cardiac function which are related to fetal maturation, cardiovascular parameters should be validated in the fetus and used with caution. Despite these precautions, in expert hands and with appropriate ultrasound equipment, evaluation of cardiac function is feasible in most fetuses. Functional fetal echocardiography is a promising tool that may soon be incorporated into clinical practice. Research is warranted to further refine the contribution of fetal cardiac assessment to the diagnosis, monitoring, or prediction of outcomes in various fetal conditions.

Pulsed-wave tissue Doppler echocardiography for the analysis of fetal cardiac arrhythmias

OBJECTIVES

Rhythm analysis of the fetal heart is hampered by the inability to routinely obtain electrocardiographic recordings of the fetus. Doppler studies of fetal cardiac tissue movements, assessing cardiac movements both qualitatively and quantitatively, have recently been described. We used a conventional high-resolution ultrasound system to obtain rhythm data from pulsed-wave tissue Doppler signals of the fetal heart in normal cardiac rhythm and in a variety of fetal cardiac arrhythmias.

METHODS

Fifty-five fetuses with normal (sinus) rhythm, 45 fetuses with rhythm disturbances and two neonates (one with arrhythmia and one with normal sinus rhythm) were studied. Using a conventional high-resolution ultrasound system equipped for fetal studies, but without specific tissue Doppler hardware or software, we performed pulsed-wave tissue Doppler echocardiography (PW-TDE) of atrioventricular valve ring excursions to study the atrial and ventricular mechanical actions. In the neonates, electrocardiograms were also recorded.

RESULTS

PW-TDE in normal fetuses shows a typical pattern of tissue motion parallel to the long axis of the heart and in the opposite direction to the blood flow, both in systole and diastole. This pattern is easily obtained from the tricuspid valve annulus in normal sinus rhythm and shows characteristic changes in various fetal arrhythmias.

CONCLUSION

PW-TDE of atrioventricular valve annulus movement patterns may prove to be a valuable additional tool for assessing fetal cardiac arrhythmias.

Tissue Doppler echocardiographic markers of cardiac dysfunction in small-for-gestational age fetuses

OBJECTIVE

The objective of the study was to evaluate echocardiographic markers of cardiac dysfunction in small-for-gestational age (SGA) fetuses with normal umbilical artery Doppler.

STUDY DESIGN

Cardiac function was evaluated in 58 SGA (mean gestational age, 38 weeks) and 58 gestational-age matched normally grown fetuses by conventional echocardiography (peak early [E] and late [A] ratios and myocardial performance index [MPI]), and tissue Doppler imaging (TDI) (annular peak velocities and MPI').

RESULTS

With conventional echocardiography, SGA fetuses had a nonsignificant trend to increased E/A ratios and left MPI compared with controls. TDI demonstrated that SGA fetuses had significantly lower right E' and A' peak velocities and higher MPI' values.

CONCLUSION

These findings further support that a proportion of SGA fetuses have true late-onset intrauterine growth restriction, which is associated with subclinical cardiac dysfunction, as previously described for early-onset intrauterine growth restriction.

Techniques for assessing cardiac output and fetal cardiac function

Fetal echocardiography was initially used to diagnose structural heart disease, but recent interest has focused on functional assessment. Effects of extracardiac conditions on the cardiac function such as volume overload (in the recipient in twin-twin transfusion syndrome), a hyperdynamic circulation (arterio-venous malformation), cardiac compression (diaphragmatic hernia, lung tumours) and increased placental resistance (intrauterine growth restriction and placental insufficiency) can be studied by ultrasound and may guide decisions for intervention or delivery. A variety of functional tests can be used, but there is no single clinical standard. For some specific conditions, however, certain tests have shown diagnostic value.

Gestational age- and estimated fetal weight-adjusted reference ranges for myocardial tissue Doppler indices at 24-41 weeks' gestation

OBJECTIVES

To construct gestational age (GA)- and estimated fetal weight (EFW)-adjusted reference ranges for tissue Doppler cardiac function parameters from 24 to 41 weeks' gestation.

METHODS

This was a prospective cross-sectional observational study involving 213 singleton pregnancies between 24 and 41 weeks' gestation. Myocardial peak velocities and myocardial performance index (MPI') were measured by tissue Doppler ultrasonography (values indicated by 'prime') in the left and right annulus and interventricular septum. Left and right atrioventricular parameters were also measured by conventional Doppler and ratios between the values found by the two methods calculated. Regression analysis was used to determine GA- and EFW-adjusted reference ranges and to construct nomograms for tissue Doppler parameters.

RESULTS

All myocardial peak velocities, left and right E'/A' and left MPI' showed a progressive increase with GA. In contrast, left and right E/E' showed a progressive decline. Septal E'/A', and right and septal MPI' remained constant. Myocardial peak velocities showed a progressive increase with increasing fetal weight.

CONCLUSIONS

Normal data of fetal myocardial peak velocities, their ratios and MPI' by tissue Doppler adjusted by GA and EFW are provided. The reported reference values may be useful in research or clinical studies and can be used in fetuses with intrauterine growth restriction.

Usefulness of myocardial tissue Doppler vs conventional echocardiography in the evaluation of cardiac dysfunction in early-onset intrauterine growth restriction

OBJECTIVE

To evaluate cardiac function by tissue Doppler imaging vs conventional echocardiography in intrauterine growth restriction.

STUDY DESIGN

A prospective study in 25 intrauterine growth restriction, and in 50 normally grown fetuses between 24 and 34 weeks. Conventional echocardiography (E/A ratios, outflow tract velocities and myocardial performance index), and tissue Doppler (myocardial peak velocities, E'/A' ratios and myocardial performance index') measurements were performed.

RESULTS

With conventional echocardiography, intrauterine growth restriction fetuses showed an increase in left myocardial performance index but similar values of E/A ratios, outflow tract velocities and right myocardial performance index as compared with controls. Tissue Doppler imaging demonstrated that intrauterine growth restriction fetuses had significantly lower systolic and diastolic myocardial velocities in mitral and tricuspid annulus, higher mitral E'/A' ratio and higher mitral, tricuspid and septal myocardial performance index' values.

CONCLUSION

Tissue Doppler imaging demonstrated the presence of both systolic and diastolic cardiac dysfunction in intrauterine growth restriction. Tissue Doppler imaging may constitute a more sensitive tool than conventional echocardiography to evaluate cardiac dysfunction in intrauterine growth restriction.

Reversible ductus arteriosus constriction due to maternal indomethacin after fetal intervention for hypoplastic left heart syndrome with intact/restrictive atrial septum

OBJECTIVE

Fetal cardiac intervention (FCI) has been performed at our center in selected fetuses with complex congenital heart disease since 2000. Most interventions are performed in fetuses with a ductus arteriosus (DA)-dependent circulation. Indomethacin promotes closure of the DA in newborns and in fetal life, a potentially life threatening complication in fetuses with ductus-dependent congenital heart disease.

METHODS

We reviewed our experience with FCI with a focus on the frequency, features, and clinical course of ductal constriction. Fetuses undergoing FCI receive comprehensive pre- and postoperative cardiac and cerebral ultrasound evaluation, approximately 24 hours before and after the procedure, including imaging of DA flow and Doppler assessment of the umbilical artery and vein, ductus venosus, and, since 2004, the middle cerebral artery.

RESULTS

Among 113 fetuses that underwent FCI, 24 of which were older than 28 0/7 weeks gestation, 2 were found to have DA constriction due to indomethacin therapy within 24 hours of intervention. Both of these were 30-week fetuses with hypoplastic left heart syndrome and restrictive or intact atrial septum. The DA was stenotic by spectral and color Doppler, and middle cerebral and umbilical artery pulsatility indexes were depressed. After discontinuation of indomethacin, the Doppler indices improved or normalized.

CONCLUSION

Close echocardiographic monitoring of fetal Doppler flow velocities is very important after fetal intervention and indomethacin treatment, as the consequences of DA constriction in a fetus with hypoplastic left heart syndrome are potentially lethal. Sonographic evaluation should include measurement of cerebral and umbilical arterial flow velocities as well as color and spectral Doppler interrogation of the DA.