ObjectivesMyocardial 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.MethodsTVI 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.ResultsDuring 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.ConclusionEvaluating 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.

All peak myocardial velocities showed an increase with gestational age. The mechanical time intervals remained more stable throughout the second half of pregnancy. It was possible to construct reference ranges using cTDI-derived myocardial velocity traces which is a pre-requisite to distinguish between normal and abnormal fetal cardiac function.

BackgroundPresent data regarding how the fetal heart works and develops throughout gestation is limited. However, the possibility to analyze the myocardial velocity profile provides new possibilities to gain further knowledge in this area. Thus, the objective of this study was to evaluate human fetal myocardial characteristics and deformation properties using color-coded tissue velocity imaging (TVI).MethodsTVI recordings from 55 healthy fetuses, at 18 to 42 weeks of gestation, were acquired at a frame rate of 201–273 frames/s for offline analysis using software enabling retrieval of the myocardial velocity curve and 2D anatomical information. The measurements were taken from an apical four-chamber view, and the acquired data was correlated using regression analysis.ResultsLeft ventricular length and width increased uniformly with gestational age. Atrioventricular plane displacement and the E’/A’ ratio also increased with gestational age, while a longitudinal shortening was demonstrated.ConclusionsFetal cardiac muscle contractility decreases with gestational age. As numerous fetal- and pregnancy-associated conditions directly influence the pumping function of the fetal heart, we believe that this new insight into the physiology of the human fetal cardiovascular system could contribute to make diagnosis and risk assessment easier and more accurate.

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Objective: The introduction of color-coded tissue velocity imaging (TVI) in fetal medicine is quite recent, and as this method is presently evaluated and developed in regard to diagnostic precision it is of outmost importance to evaluate the reproducibility for adequate clinical use. In this study, reproducibility and intra-and inter-observer variability was assessed for offline analysis as well as echocardiography investigations. Also, we evaluated the importance of exact placement of the region of interest (ROI).Methods: TVI recordings from 21 fetuses, at a gestational age of 27 to 41 weeks, were acquired at 208-239 frames/s for subsequent offline analysis. All recordings were performed with the transducer positioned to provide an apical four-chamber view and the myocardial velocity data was obtained from basal inferoseptum. The data set was analyzed according to Bland-Altman and reproducibility was expressed as the standard error of a single determination, estimated from duplicate determinations in percentage of the total. Results:The variation of reproducibility for the echocardiography investigation ranged from 2.0% to 9.8%. The duration of left ventricular ejection, and the peak velocities of early diastolic filling and atrial contraction being the most robust events measured. The variation of inter-observer variability for the echocardiography investigation ranged from 1.5% to 8.4%, and the variation of intra-and inter-observer variability for the offline analysis ranged from 1.2% to 10.4%. Least robust were the events of shortest duration, including isovolumetric contraction and relaxation. Conclusion:We believe that TVI measurements of the fetal myocardium could be performed in the clinical routine with acceptable reproducibility.

Objectives: To investigate whether levels of cell free fetal DNA (cffDNA) assessed at 25 weeks gestation when determining fetal RHD status and PAPP-A from the combined first trimester risk assessment for trisomy 21 can identify women at risk of developing pre-eclampsia and SGA neonates. Methods: A population of 964 singleton pregnant RhD negative women with an RHD positive fetus who participated in the antenatal RHD screening programme in the Capital Region of Denmark. All women had a first trimester nuchal translucency scan and a 20 week malformation scan. Gestational age was based on CRL measurement at first trimester screening, PAPP-A was measured at 8-14 weeks. SGA was calculated using the regression equation constructed by Marsál and co-workers. We used a standard dilution curve to calculate the amounts of cffDNA. Results: A total of 38 women developed pre-eclampsia (3.9%), 15 cases of severe and 23 cases of mild pre-eclampsia. The number of neonates born SGA was 51 (5.3 %). The OR of developing mild pre-eclampsia given a cffDNA level below the 5 th centile was 4.1 (95% CI: 1.2-13.2) and the OR of developing severe pre-eclampsia given a cffDNA level above the 90 th centile was 10.2 (95% CI: 3.4-30.4). SGA was significantly associated with fetal DNA levels above the 90 th centile (P = 0.009). Amongst women diagnosed with pre-eclampsia 46% in the group with cffDNA levels above the 90 th centile delivered an SGA neonate compared to 7% in the group with cffDNA levels below the 90 th centile. Amongst women not developing pre-eclampsia the numbers were 7.1% versus 4.5%. PAPP-A levels below the 5 th centile were associated with mild pre-eclampsia, but not with SGA. Conclusions: Cell free fetal DNA is a marker for pre-eclampsia. High levels were associated with severe pre-eclampsia, low levels with mild pre-eclampsia, thus indicating different placental pathologic mechanisms. High levels of cffDNA is a poor marker of SGA independently of pre-eclampsia.

Background: In patients (pts) with sick sinus syndrome (SSS), right ventricular apical (RVA) pacing increased the risk of developing atrial fibrillation (AF). However, the mechanism of proarrhythmic effect of RVA pacing remains unclear. Methods: We performed detailed echocardiograhic examination with Tissue Doppler Imaging in 60 pts with SSS (mean age 73A9 years, 42 F) who implanted with DDD pacemakers during atrial and ventricular pacing with atrioventricular interval programmed at 120-150 mesc (ApVp mode) and AAI mode with (ApVs mode) at 70 bpm. Echo measurements were taken after 15 mins of pacing in each mode. The myocardial atrial contraction velocity was measured at annulus of right free wall (Ra), septal (Sa) and lateral free wall (La) respectively. Results: As expected, the AV interval was significantly shorter (118A25 vs.163A45 ms, P=0.002), and QRS duration was longer (146A33 vs.97A26 ms, P,0.001) during ApVp mode as compared with ApVs mode. Although there was no significant difference in left ventricular ejection fraction, left atrial (LA) ejection fraction (50A14 vs.55A14%, P=0.005), LA active emptying fraction (32A17 vs.37A16%, P=0.018) and LA filling fraction (43A13 vs. 48A13%, P=0.007) were all significant improved by 18%, 54% and 18%, respectively during ApVs mode as compared with ApVp mode. Furthermore, atrial myocardial contraction velocities among Ra (14.0A3.8 vs.15.2A4.6cm/s, P=0.026), Sa (7.8A2.6 vs. 8.8A2.8cm/s, P=0.001), and La (8.9A3.2 vs.9.7A2.7cm/s, P=0.020) were also significantly increased during ApVs mode by 12%, 19% and 21%, respectively as compared with ApVp mode (Figure). Conclusions: In pts with SSS, avoidance of RVA pacing during ApVs mode improves LA haemodynamic and mechanical function, which might contribute to a lower risk of development of AF after pacemaker implantation. P773Qualitative and quantitative assessment of 3 novel post-processing methods for enhancing echocardiographic images. Echocardiography, while a prevalent tool for assessing cardiac morphology and function, suffers from a range of artefacts that reduce its diagnostic value. This work qualitatively and quantitatively evaluates 3 novel post-processing methods for enhancing echocardiographic images. Data enhancement is achieved by utilising multiple partially decorrelated instances of a cardiac cycle acquired through a single acoustic window. Such information has until now been largely disregarded during data post-processing. Moreover, unlike past approaches, data enhancement is achieved without filtering out information based on static or adaptive selection criteria. Qualitative assessment using 32 clinical datasets demonstrated (i) suppression of cavity noise, (ii) increase in tissue/cavity contrast, and (iii) visual enhancement of tissue structures previously masked-out by various artefacts (Figure 1). The effect of each post-processing method on the diagnostic value of cardiac ultrasound data was quantitatively assessed by examining the repeatability coefficient variations (via Bland-Altman plots) in clini...