Objective: To test the hypothesis that identical twins show no inter-twin differences in cardiovascular structure or physiology in fetal life unless there has been twin-twin transfusion syndrome. ...Design: Unselected prospective case–control observational study of fetoplacental haemodynamics including echocardiography at a median of 24 (16.7 to 32.3) weeks, with postnatal confirmation of congenital heart disease or normality. Setting: Fetal medicine unit. Patients: 136 women with monochorionic diamniotic twin pregnancies, of which 47 fetal twin pairs (35%) had twin-twin transfusion syndrome. Results: There were no haemodynamic differences between the bigger fetus (twin 1) and the smaller co-twin (twin 2) in uncomplicated monochorionic diamniotic pairs. In twin-twin transfusion syndrome, recipient fetuses had increased aortic and pulmonary velocities compared with their donor co-twins (mean (SD): 0.73 (0.23) m/s and 0.63 (0.14) m/s), respectively, v 0.53 (0.16) m/s and 0.48 (0.10) m/s in donor twins; p = 0.003 (aortic) and < 0.0001 (pulmonary)), and also in comparison with twin 1 and twin 2. The overall prevalence of congenital heart disease was increased above that in singletons (3.8% v 0.56%; 6.9% in twin-twin transfusion v 2.3% in uncomplicated monochorionic diamniotic twins), with inter-twin discordance for defects. The prevalence in recipient twins was 11.9% (p = 0.014 v uncomplicated control twins). Conclusions: Fetuses with an identical genome but no circulatory imbalance have similar cardiovascular physiology but discordant phenotypic expression of congenital heart disease. The high prevalence of congenital heart disease in monochorionic diamniotic twins merits detailed fetal echocardiography.
Objective: To compare ventricular long axis function in fetuses of diabetic mothers (FDM) with contemporaneously studied normal controls (N) and to assess the effect of pre-pregnancy diabetic control ...on these measurements. Design: Long axis function was compared in 41 FDM and 159 N fetuses in a cross sectional observational study. Setting: Fetal medicine unit. Methods and results: Echocardiography confirmed structural normality. Pulsed wave valvar Doppler velocimetry, lengthening and shortening myocardial velocities, and amplitude of ventricular long axis movement were recorded at the base of the left and right ventricular free walls and septum. Periconceptual diabetic control was assessed by haemoglobin A1c (HbA1c) in early pregnancy. Doppler and myocardial velocities were negatively related and myocardial thickness was positively related with HbA1c. In both cohorts all variables except mitral and tricuspid late filling (A wave) velocities were dependent on gestational age. FDM gestational age related values were higher for most variables and robust analysis of covariance showed significantly different maturation patterns in mitral valve E:A ratio (p = 0.036) and pulmonary velocity (p = 0.04), late lengthening myocardial velocities (left p = 0.016 and right p = 0.066), left myocardial shortening velocities (p = 0.008), and left free wall (p = 0.03) and septal (p = 0.04) amplitude of motion. FDM septal thickness was significantly increased throughout gestation (p < 0.0001). Conclusion: Periconceptual diabetic control influences fetal cardiac performance and myocardial hypertrophy but, unlike the pathophysiology of adult ventricular hypertrophy, is accompanied by functional adaptation. It is unlikely to explain the increased rate of late stillbirth observed in diabetic pregnancies.
Background Chronic hypertension in adults causes arterial lengthening in major arteries, but the effects of early fetal hypertension on the twin-twin transfusion syndrome recipient’s vascular ...architecture remains unknown. Objective We hypothesize that arterial cord redundancy is related to recipient hypertension and subsequent heart failure. Our objectives were to: (1) establish a 3-dimensional color Doppler ultrasound method of measuring umbilical arterial length relative to its corresponding venous segment in the umbilical cord using artery vein angle; (2) compare recipient artery vein angle to gestational age-matched controls; and (3) test the association of artery vein angle with recipient heart failure. Study Design We compared 3 groups prospectively: twin-twin transfusion syndrome pregnancies undergoing fetoscopic laser surgery (preoperatively) and 2 groups of gestational age-matched controls: uncomplicated monochorionic-diamniotic twin pregnancies and healthy singletons. Using a 3-dimensional color-Doppler volume image of 5 cm of cord near the placental insertion, we traced the umbilical artery and vein producing umbilical artery:vein length, (artery vein index) and measured the artery vein angle between umbilical artery and vein. Correlation of artery vein angle to twin-twin transfusion syndrome stage, maximum vertical pocket, umbilical arterial indices, ductus venosus Doppler, and brain natriuretic peptide were performed. We used pulsed-wave and tissue Doppler to measure tissue Doppler velocities and indexed cardiac output and correlated these with artery vein angle. Comparative statistics, including multivariable linear regression, examined the relationship between umbilical arterial Doppler indices and artery vein angle. Results Artery vein angle and artery vein index correlated significantly ( R 2 , 0.86; P < .0001), hence, artery vein angle was used for analysis. Mean artery vein angle was 33.1 ± 31.5 degrees in recipients (n = 44), 9.5 ± 6 degrees in monochorionic-diamniotic (n = 11; 22 fetuses), and 8.9 ± 8.3 degrees in singleton controls (n = 16) ( P < .001). An artery vein angle ≥26 degrees (>95th percentile for controls) was measured in 52% recipients. Artery vein angle was higher in twin-twin transfusion syndrome stage 3R vs 1 ( P = .001). Artery vein angle increased with increasing umbilical arterial pulsatility index ( P < .001), and decreased with increasing resistance index ( P = .02) after adjusting for gestational age. Interrater agreements to categorize abnormal artery vein angle values was 95% ( P < .001). Abnormal ductus venosus Doppler and elevated recipient amniotic fluid N-terminal pro-brain natriuretic peptide/protein levels correlated significantly with artery vein angle. Abnormal artery vein angles were associated with decreased indexed cardiac output, lower tissue Doppler velocities, higher right-sided Tei indices, and severe tricuspid regurgitation. Conclusion Umbilical arterial lengthening occurs in 52% of recipients and is associated with abnormal Doppler flows, low systolic tissue Doppler velocities, reduced cardiac output, and elevated markers of cardiac failure. This may reflect chronicity and severity of hypertension in the recipient fetus. Further research is needed to explore the mechanisms of elongation and long-term implications.
Atrial distension after Fontan operation may predispose to arrhythmia. Modifications aimed at decreasing the extent of right atrial distension (total cavopulmonary connection, TCPC) have been ...associated with a lower incidence of early arrhythmia, but serial evaluation has not been performed.
All 119 patients undergoing TCPC between March 1987 and December 1993 were enrolled in a prospective study to evaluate the incidence and determinants of arrhythmia by use of ambulatory ECG (AECG) monitoring. Median age at surgery was 5.9 years (range, 0.5 to 19.7 years), and median follow-up was 4.9 years (2.0 to 8.7 years). AECGs were performed before and after surgery and serially during follow-up. There were 17 early deaths, including 8 among 20 patients who had new arrhythmia documented in the operating in the operating room or intensive care unit. For the 102 patients who survived > 30 days after surgery, the proportion free of new AECG arrhythmia or first arrhythmic symptoms was 93% (CI, 89% to 99%) at 2 years and 78% (CI, 66% to 90%) at 5 years. Actuarial analysis treats occurrence of arrhythmia as permanent; however, most of the arrhythmia during follow-up was transient, so that the proportion of patients without arrhythmia was similar before and during follow-up. To date, there has been only 1 late arrhythmic death.
The low prevalence of clinically important arrhythmia during medium-term follow-up supports the TCPC as the preferred option for Fontan surgery.
What's Already Known About This Topic?
Fetal cardiology is a highly specialized field that crosses multipledisciplines. In order to expand knowledge and discovery, a structured organization which ...fosters multidisciplinary research collaboration across institutions is needed.
What Does This Study Add?
The newly formed Fetal Heart Society is a non-profit multidisciplinary research organization with an overarching goal of advancing the field of fetal cardiovascular care and science through collaborative research, education, and mentorship. Information can be found at fetalheartsociety.org
Cardiac abnormality was present in 448 cases (27%), with persistent LSVC in 12 cases (2.7%). ...the odds ratio of a fetus having a cardiac defect if a LSVC is detected is 8.43 (95% CI 2.71 to 26.29).
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