Assessment of fetal cardiac function using tissue Doppler techniques.

OBJECTIVE: Tissue Doppler echocardiography is being increasingly used in fetal medicine as a clinical and research tool. The objective of this study was to review the current status of tissue Doppler imaging (TDI) techniques applied to the fetus. METHODS: Fetal cardiac function was evaluated using spectral and color TDI modes in normal fetuses and in several clinical conditions. RESULTS: Annular peak velocities and their ratios as well as the myocardial performance index were evaluated using spectral TDI, and changes throughout gestation were described. Color TDI has several limitations in fetal life, particularly the use of low frame rates with current methods of acquisition and the lack of normal references for deformation parameters. CONCLUSIONS: Despite its limitations, TDI is a sensitive and promising method to evaluate fetal cardiac function.

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.

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.

Ultrasound examination at term for predicting the outcome of delivery in women with a previous cesarean section.

OBJECTIVE: To evaluate if ultrasound variables at term are associated with the mode of delivery in women with previous cesarean section (PCS). METHODS: This was a prospective study of singleton pregnant women who planned a trial of vaginal birth after cesarean delivery. Cervical length, posterior cervical angle, head-perineum distance, and estimated fetal weight were measured at 37-39 weeks of gestation. RESULTS: One hundred forty-four pregnancies were examined and vaginal delivery was achieved in 98 women (73%). Logistic regression analysis identified cervical length, head-perineum distance, age, previous vaginal delivery, previous cesarean for dystocia, and Bishop score as predictors of vaginal delivery. Combining ultrasound and clinical parameters, two models for risk scoring that differ in the variable Bishop score or cervical length were constructed. The AUC of these models was 0.867 and 0.855, respectively. CONCLUSIONS: In women with a PCS, measurement of cervical length and head-perineum distance at term is associated with the mode of delivery. A combination of clinical and sonographic parameters at term can predict the likelihood of vaginal delivery.