Marie-Josée Raboisson

Early Intertwin Differences in Myocardial Performance During the Twin-to-Twin Transfusion Syndrome

Background—In the twin-to-twin transfusion syndrome (TTTS), pressure rather than volume overload is increasingly considered as a key factor in the pathogenesis of the cardiomyopathy of the recipient twin. If this is the case, cardiac dysfunction should be among the first signs observed with TTTS. The objective of this study was to determine whether intertwin differences in myocardial function are modified early in the course of TTTS and whether they can help to differentiate this condition from intrauterine growth restriction (IUGR). Methods and Results—Eight variables were analyzed on the first fetal echocardiography on 21 pairs of twins with TTTS and 11 with IUGR. No difference was found between the 2 groups for the cardiothoracic ratio, pulsatility indices in the umbilical and middle cerebral arteries, and peak velocity of the middle cerebral artery. Significant difference was found for ventricular septal thickness, but with no association with the conditions under study. With TTTS, left ventricular shortening fraction was consistently greater in the donor twins, and myocardial performance indices (MPIs) were elevated in the recipient twins. This increase in MPI was caused by a lengthening of the isovolumic periods compared with those of the donor twin: left ventricular and right ventricular isovolumic periods 0.105±0.047 and 0.097±0.026 seconds, respectively, for the recipient twins versus 0.0561±0.46 and 0.065±0.03 seconds, respectively, for the donor twins (P<0.001). These changes in the isovolumic periods were mainly due to significant prolongation of isovolumic relaxation times. A change in left ventricular MPI ≥0.09 combined with a change in right ventricular MPI ≥0.05 would identify a TTTS with a sensitivity of 75% and a false-positive rate of 9%. Conclusions—The observed diastolic function impairment goes along with the pressure-overload pathogenic concept proposed in TTTS. Assessment of intertwin difference in MPI is a valuable tool for early differential diagnosis between TTTS and isolated IUGR.

Reference values for an index of fetal aortic isthmus blood flow during the second half of pregnancy

During fetal life, the parallel position of the two cardiac ventricles confers a special status to the aortic isthmus. Flow through the isthmus reflects the balance between the performances of the two ventricles and their respective peripheral impedances. This study proposes a fetal aortic isthmus flow velocity index and its reference values defined on the basis of gestational age (GA).

Relevance of measuring diastolic time intervals in the ductus venosus during the early stages of twin–twin transfusion syndrome

To determine if the discrete myocardial diastolic dysfunction documented previously in the recipient twin during the early stages of twin–twin transfusion syndrome (TTTS) has any repercussion on flow velocities through the ductus venosus (DV) and to investigate if this could allow early differentiation between TTTS and selective intrauterine growth restriction (IUGR).

Polymorphisms of ABCC5 and NOS3 genes influence doxorubicin cardiotoxicity in survivors of childhood acute lymphoblastic leukemia

Anthracyclines are efficient chemotherapy agents. However, their use is limited by anthracycline-induced cardiotoxicity (CT). We investigated the influence of polymorphisms in doxorubicin metabolic and functional pathways on late-onset CT as estimated by echocardiography in 251 childhood acute lymphoblastic leukemia (cALL) patients. Association analyses revealed a modulating effect of two variants: A-1629 T in ABCC5, an ATP-binding cassette transporter, and G894T in the NOS3 endothelial nitric oxide synthase gene. Individuals with the ABCC5 TT-1629 genotype had an average of 8–12% reduction of ejection (EF) and shortening fractions (SF; EF: P<0.0001, and SF: P=0.001, respectively). A protective effect of the NOS3 TT894 genotype on EF was seen in high-risk patients (P=0.02), especially in those who did not receive dexrazoxane (P=0.002). Analysis of an additional cohort of 44 cALL patients replicated the ABCC5 association but was underpowered for NOS3. In summary, we identified two biomarkers that may contribute to cALL anthracycline CT risk stratification.

The PETALE study: Late adverse effects and biomarkers in childhood acute lymphoblastic leukemia survivors

Childhood cancer survivorship issues represent an established public health challenge. Most late adverse effects (LAEs) have been demonstrated to be time and treatment dependent. The PETALE study is a multidisciplinary research project aiming to comprehensively characterize LAEs and identify associated predictive biomarkers in childhood acute lymphoblastic leukemia (cALL) survivors.

Prenatal diagnosis of long QT syndrome with the superior vena cava–aorta Doppler approach

We describe a fetus at 36 weeks with long QT syndrome presenting with variable types of atrioventricular blocks, ventricular premature beats, and torsades de pointes. All these diagnoses were made with the superior vena cava-aorta Doppler approach and confirmed with postnatal electrocardiography.

Ventricular outputs, central blood flow distribution and flow pattern through the aortic isthmus of fetuses with simple transposition of the great arteries

Our objective was to determine the impact of simple transposition of the great arteries (TGA) on fetal left ventricular (LV) and right ventricular (RV) performances and central circulatory dynamics including the aortic isthmus.

Large Amplatzer atrial septal occluder in growing children: an echographic study

BACKGROUND Lesions of adjacent structures have been reported after closure of large atrial septal defects with the Amplatzer septal occluder. In children, growth of the heart should modify the initial relationship between the device and surrounding structures. AIM To compare the relationship between large Amplatzer septal occluder and adjacent cardiac structures at short-, mid-, and long-term follow-up in at-risk paediatric population using echocardiography. METHODS A total of 25 children (4.6±2.9 years old, 18 girls) with the largest atrial septal defect devices implanted between 1997 and 2002 were enrolled prospectively for complete echocardiogram 17.8±10.5 months (mid-term follow-up) and 8.8±0.9 years (long-term follow-up) after the procedure. RESULTS were compared with the echocardiogram carried out 2.1±3.4 days after the procedure (short-term follow-up). RESULTS The minimal distance between the left disk and the mitral valve increased: 1.4±2.0 mm at short-term and 5.1±2.3 mm at long-term follow-up (p<0.05), leading to less contact between the disk and the anterior leaflet and less mitral regurgitation (10 at short-term, 4 at long-term follow-up, p<0.05). The number of devices straddling the aorta decreased from 17 to 12 at long-term follow-up (p<0.05). There was protrusion of disk in the venous structure in seven patients on the first echocardiogram, which disappeared at long-term follow-up. CONCLUSION Although frequently in close contact with the aortic root, mitral valve, or venous returns, large devices tend to centre and move away from the surrounding structures, with decreased risk for long-term distortion.

Long-Term Follow-Up of Large Atrial Septal Occluder (Amplatzer Device) With Cardiac MRI in a Pediatric Population

OBJECTIVE The purpose of this study is to evaluate the position and the progress of large Amplatzer septal occluder (ASO) devices relevant to adjacent cardiac structures in growing children using MRI. MATERIALS AND METHODS Institutional review board approval for this study was obtained. Twenty-five children who underwent large ASO implantation were evaluated using MRI. All subjects were initially imaged 7 years earlier using the same protocol. Spatial and dynamic relationships between the ASO and the adjacent cardiac structures were compared to assess the progress over the 7-year growth span with respect to protrusion, contact, and extrinsic deformity of the mitral valve, the left atrial roof, the aortic annulus and root, and the ostia of adjacent veins. RESULTS No long-term device-related complications were documented during follow-up. Impingement of the ASO into the opening of the right superior and inferior pulmonary veins and the superior and inferior vena cava resolved completely, compared with initial observations, in five of 16, three of three, five of 10, and three of nine patients, respectively, and significantly regressed in the remaining patients. The devices contact with the mitral valve and the left atrial roof and the aortic root deformity resolved in seven of 10, 11 of 20, and 10 of 18 cases, respectively. CONCLUSION The distance between the ASO and the surrounding structures increases with time in growing children who require large ASO devices, likely decreasing the risk of long-term complications.

Aortic Isthmus Flow Recording Predicts the Outcome of the Recipient Twin after Laser Coagulation in Twin-Twin Transfusion Syndrome

Introduction: The objective was to assess the prognostic value of the systolic flow through the aortic isthmus in monochorionic pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated by placental laser ablation. Material and Methods: Fetal echocardiography and outcome data of 105 cases of TTTS treated by laser photocoagulation of placental anastomoses were reviewed. Hemodynamic parameters were collected before and after treatment. The isthmic systolic index (ISI) was calculated as the peak systolic velocity/systolic nadir ratio. Results: A total of 105 laser coagulations were studied. Fetal echocardiography pre- and post-laser were available in 68 cases, including 55 with data on aortic isthmic Doppler. Survival rates were 17, 22, and 61% for 0, 1, or 2 twins, respectively. At least 1 twin was delivered alive in 83% of the pregnancies. The mean gestational age at surgery was 21 weeks (range 16-26). Median ISI values were similar for donor and recipient twins, before and after laser ablation (all p > 0.05). A lower recipient ISI before laser was related to early recipient demise within 24 h (p = 0.04). Discussion: A lower ISI before placental laser ablation for TTTS is associated with postoperative demise of the recipient twin.