Association between fetal growth, cerebral blood flow and neurodevelopmental outcome in univentricular fetuses.

OBJECTIVE: To investigate the association of fetal growth and cerebrovascular resistance at different periods in gestation with neurodevelopment (ND) at 14 months in the univentricular subject. METHODS: We reviewed serial prenatal ultrasound (US) examinations from 133 infants enrolled in the Pediatric Heart Network's Single Ventricle Reconstruction or Infants with Single Ventricle trials, including a subset of 82 infants in whom ND was assessed at 14 months using mental (MDI) and psychomotor (PDI) developmental indices. US examinations were assigned to one of four gestational time periods: (1) 20-23 weeks, (2) 24-29 weeks, (3) 30-33 weeks and (4) ≥ 34 weeks. Middle cerebral artery (MCA) flow velocity was measured and pulsatility index (PI), a measure of downstream resistance, was calculated. Data on fetal head circumference (HC), femur length, abdominal circumference (AC) and estimated fetal weight (EFW) were collected and their Z-scores were calculated. We evaluated the rate of change of these parameters over time within individuals, tested correlations between fetal growth and ND and assessed predictors of ND using linear regression. RESULTS: The mean prenatal HC Z-score was < 0 at each gestational-age period and became more negative later in pregnancy. There was less growth in HC from time period 3 to period 4 compared with from period 2 to 3 (Δ HC Z-score, -0.07 ± 0.1 vs 0.11 ± 0.22, P = 0.03). Though ND did not correlate with HC, HC Z-score or MCA-PI Z-score, HC growth from period 2 to period 3 correlated with MDI (r = 0.45, P = 0.047). AC Z-score in period 4 predicted MDI (ß = 4.02, P = 0.04). EFW Z-score and AC Z-score in period 2 predicted PDI (ß = 10.6, P = 0.04 and ß = 3.29, P = 0.047, respectively). Lower MCA-PI at initial US predicted higher PDI (ß = -14.7, P = 0.03). CONCLUSION: In univentricular fetuses, lower cerebrovascular resistance may be protective for ND. Decreased fetal somatic growth may predict developmental abnormalities. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Screening fetal echocardiography in diabetic mothers with normal findings on detailed anatomic survey.

OBJECTIVES: To evaluate the benefit of second-trimester fetal echocardiography for women with diabetes whose fetuses had no obvious heart disease on a detailed anatomic survey performed at skilled, high-volume obstetric centers, and to investigate the technical limitations of fetal echocardiography in this patient population. METHODS: This was a retrospective descriptive review of fetal echocardiograms performed at Children's Hospital Boston from 2000 to 2005. All women referred during the second trimester for fetal echocardiography because of maternal diabetes were included. Those with severe heart disease suspected on obstetric ultrasound examination were excluded. RESULTS: There were 584 initial fetal echocardiograms. No patients were diagnosed with severe heart disease prenatally. Nineteen were diagnosed with suspected mild heart disease (such as small ventricular septal defect), five of whom had normal follow-up fetal evaluation and five of whom had normal postnatal evaluation. Most of these pregnancies did not have a postnatal cardiac evaluation. Forty-seven fetuses had benign cardiac findings. Nearly one third of patients had imaging that was felt to be limited or incomplete, mostly due to poor acoustic windows. Forty-eight patients were asked to return for at least one follow-up visit, most due to the inability to complete the exam at the initial visit. CONCLUSIONS: In an environment with access to high-volume, skilled comprehensive ultrasound services, fetal echocardiography by a pediatric cardiology program adds little to the care of women with diabetes and no suspected heart disease on a detailed anatomic survey. Poor acoustic windows frequently necessitate multiple visits.

Changes in left heart hemodynamics after technically successful in-utero aortic valvuloplasty.

OBJECTIVE: Severe aortic stenosis in the mid-gestation fetus can progress to hypoplastic left heart syndrome (HLHS). @ In-utero aortic valvuloplasty is an innovative therapy to promote left ventricular growth and function and potentially to prevent HLHS. This study evaluated the effects of mid-gestation fetal balloon aortic valvuloplasty on subsequent fetal left ventricular function and left heart Doppler characteristics. METHODS: We reviewed fetuses with aortic stenosis that underwent attempted in-utero aortic valvuloplasty between 2000 and 2006. Pre-intervention and the latest post-intervention fetal echocardiograms were analyzed to characterize changes in left heart function and Doppler characteristics in utero. RESULTS: Forty-two fetuses underwent attempted aortic valvuloplasty during the study period, 12 of which were excluded from analysis secondary to inadequate follow-up data, termination or fetal demise. Study fetuses (n = 30) underwent pre-intervention echocardiography at a median gestational age of 23 weeks, and were followed for a median of 66 +/- 23 days post-intervention. In 26 fetuses, aortic valvuloplasty was technically successful. Among these 26, left heart physiology was abnormal pre-intervention and improved or normalized after intervention in most cases: biphasic mitral inflow was present in 5/25 (20%) cases pre-intervention and in 21/23 (91%) post-intervention (P < 0.001); moderate or severe mitral regurgitation was present in 14/26 (54%) cases pre-intervention and in 5/23 (22%) post-intervention (P = 0.02); bidirectional flow across the patent foramen ovale was present in 0/26 cases pre-intervention and in 6/25 (24%) post-intervention (P = 0.01); antegrade flow in the transverse arch was present in 0/25 cases pre-intervention and in 17/26 (65%) post-intervention (P < 0.001). The left ventricular ejection fraction increased from 19 +/- 10% pre-intervention to 39 +/- 14% post-intervention (P < 0.001). These changes were not observed in control fetuses (n = 18). CONCLUSION: Fetal aortic valvuloplasty, when technically successful, improves left ventricular systolic function and left heart Doppler characteristics.

The risk of having additional obstructive lesions in neonatal coarctation of the aorta.

Infants with coarctation of the aorta may have obstructions at other sites within the left heart which are not always apparent on the initial echocardiogram. The magnitude of the risk of having the additional obstructions is not well described, with few reliable quantitative criterions for identifying patients at the highest risk. We determined the frequency of additional, late appearing, stenotic lesions within the left heart, and the predictive morphologic features on the initial cross-sectional echocardiogram. We identified all patients with coarctation of the aorta diagnosed by 3 months of age, excluding those with complex cardiac disease or definite additional stenotic lesions at presentation, leaving 101 patients for study. At follow-up, 31 stenotic lesions were diagnosed in 23 patients, 15 of whom had at least 1 intervention. Mitral stenosis was diagnosed in 11 patients, aortic stenosis in 10, subaortic stenosis in 8, and supravalvar aortic stenosis in 2. The probability for freedom from obstructive lesions was 81% at 1 year, 74% at 3 years, and 70% at 5 years. Echocardiographic predictors of mitral stenosis included smaller mitral valvar annuluses, presence of a mean transmitral gradient between 2.5 and 5.0 mmHg, and elongation of the area of intervalvar fibrous continuity. Predictors of aortic stenosis were smaller mitral valvar annuluses, an initial aortic valvar gradient between 15 and 20 mmHg, and obliteration of the commissure between the right and non-coronary leaflets of the aortic valve. Predictors of subaortic stenosis were smaller mitral valvar annuluses and elongation of the area of intervalvar fibrous continuity. Patients with Z-scores for the diameter of the mitral valve of less than -1 were at the highest risk for manifesting obstructive lesions at any level. Associated stenoses in the left heart are common in the setting of aortic coarctation. When Doppler data is equivocal, features of the cross-sectional echocardiogram can identify the sub-group of infants at increased risk.

Use of high-frame rate imaging and doppler tissue echocardiography in the diagnosis of fetal ventricular tachycardia.

Ventricular tachycardia has rarely been diagnosed in the fetus. We describe a 31-week-old fetus with ventricular tachycardia and severely depressed ventricular function. M-mode and 2-dimensional Doppler tissue echocardiography were used in this study to assess the nature of the arrhythmia. The complete atrioventricular dissociation inherent to the diagnosis of ventricular tachycardia was particularly easy to detect with M-mode Doppler tissue echocardiography. Moreover, the onset and the pattern of propagation of the ventricular arrhythmia could be easily identified with 2-dimensional Doppler tissue echocardiography. Doppler tissue echocardiography facilitates the diagnosis of ventricular tachycardia and adds new information that is not available by other techniques.

Sodium channel abnormalities are infrequent in patients with long QT syndrome: identification of two novel SCN5A mutations.

Long QT syndrome (LQTS) is a heterogeneous disorder caused by mutations of at least five different loci. Three of these, LQT1, LQT2, and LQT5, encode potassium channel subunits. LQT3 encodes the cardiac-specific sodium channel, SCN5A. Previously reported LQTS-associated mutations of SCN5A include a recurring three amino acid deletion (DeltaKPQ1505-1507) in four different families, and four different missense mutations. We have examined the SCN5A gene in 88 index cases with LQTS, including four with Jervell and Lange-Nielsen syndrome and the remainder with Romano-Ward syndrome. Screening portions of DIII-DIV, where mutations have previously been found, showed that none of these patients has the three amino acid deletion, DeltaKPQ1505-1507, or the other four known mutations. We identified a novel missense mutation, T1645M, in the DIV; S4 voltage sensor immediately adjacent to the previously reported mutation R1644H. We also examined all of the additional pore-forming regions and voltage-sensing regions and discovered another novel mutation, T1304M, at the voltage-sensing region DIII; S4. Neither T1645M nor T1304M were seen in a panel of unaffected control individuals. Five of six T1304M gene carriers were symptomatic. In contrast to previous studies, QT(onset-c) was not a sensitive indicator of SCN5A-associated LQTS, at least in this family. These data suggest that mutations of SCN5A are responsible for only a small proportion of LQTS cases.

Absent right superior vena cava in visceroatrial situs solitus.

Absence of the right superior vena cava (SVC) in visceroatrial situs solitus is rare (0.07% to 0.13% of congenital cardiovascular malformations), and little is known about the type and frequency of additional heart defects and arrhythmias. We reviewed previous publications and present 9 new cases. Based on 121 known cases, we found that this anomaly is typically characterized by: (1) persistence of the left SVC draining into the right atrium by way of the coronary sinus, and (2) left-sided azygos vein draining into the left SVC. Less constant features were: (3) additional cardiovascular malformations (46%), and (4) rhythm abnormalities (36%) that usually appeared related to the complications of old age. Since absence of the right SVC is clinically silent, its status should be assessed echocardiographically prior to invasive medical or surgical procedures. This is important to avoid various management difficulties during the following procedures: (1) implantation of a transvenous pacemaker, (2) placement of a pulmonary artery catheter for intraoperative or intensive care unit monitoring without fluoroscopy, (3) systemic venous cannulation for extracorporeal membrane oxygenation, (4) systemic venous cannulation for cardiopulmonary bypass, (5) partial or total cavopulmonary anastomoses; and (6) orthotopic heart transplantation and endomyocardial biopsies.

Anastomotic pseudoaneurysm of the ventricle after homograft placement in children.

A pseudoaneurysm of the right ventricle was diagnosed postoperatively in 8 patients between 1986 and 1992. One pseudoaneurysm formed after placement of a Carpentier-Edwards conduit and the other seven arose after placement of a homograft between the right ventricle and the pulmonary artery. Both aortic (n = 3) and pulmonary (n = 4) homografts had been used. In 6 patients, the homografts had been augmented proximally with Dacron, Gore-Tex, or pericardium. Pseudoaneurysms originated between the augmentation patch and the homograft in 4 patients, between the homograft or conduit and the myocardium in 3 patients (1 patient with and 2 without an augmentation patch), and between the patch and the myocardium in 1 patient. The prior operations performed were placement of a palliative conduit for tetralogy of Fallot with pulmonary atresia (n = 5), repair of truncus arteriosus (n = 2), and repair of absent pulmonary valve syndrome (n = 1). Pseudoaneurysms were discovered from 5 weeks to 4 years after the operation. Symptoms were present in 3 patients; in the others, diagnosis was made during follow-up on the basis of routine imaging studies. Symptoms, when present, were due to compression of surrounding mediastinal structures. Pseudoaneurysms ranged in diameter from 1.0 to 5.0 cm. Echocardiography and color-flow mapping reliably identified the pseudoaneurysm in the 6 patients in whom it was performed. Characteristic features included a well-defined, narrow aneurysm neck leading to an extracardiac echo-free space. Color-flow mapping demonstrated to-and-fro flow through the neck of the aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiofrequency ablation of accessory pathways associated with congenital heart disease including heterotaxy syndrome.

Congenital heart disease complicates the management of most accessory pathway-mediated tachycardias and also increases the challenge of radiofrequency ablation. Since 1990, radiofrequency ablation of accessory atrioventricular (AV) pathways has been attempted in 10 patients (age range 3.5 months to 30 years) with congenital heart disease: Ebstein's anomaly (n = 5), heterotaxy with AV discordance (n = 3), tetralogy of Fallot (n = 1) and total anomalous pulmonary venous return (n = 1). Eight patients had manifest Wolff-Parkinson-White syndrome and 2 had concealed pathways. Five patients had multiple pathways including 4 of the 5 with Ebstein's anomaly. Of 16 pathways total, 15 were associated with the tricuspid valve including all pathways in the patients with Ebstein's anomaly and heterotaxy. The His bundle area was identified in all patients and involved an anterior AV node in 2 of 3 with heterotaxy. Ablation was performed on the atrial side of the AV ring in all cases. No instance of AV block was encountered. Complete success was achieved in 6 patients including the 3 with heterotaxy. In 2 patients, manifest preexcitation was eliminated and clinical symptoms were greatly modified. The procedure was transiently successful in 1 patient who later had surgical interruption of the accessory pathway during tetralogy of Fallot repair. Ablation was unsuccessful in 1 patient. Thus, the overall success was 80%.