Anita Szwast

Perinatal and early surgical outcome for the fetus with hypoplastic left heart syndrome: a 5-year single institutional experience.

To review our experience with the prenatal diagnosis of hypoplastic left heart syndrome (HLHS). Our goal was to establish the benchmark for perinatal and early surgical outcome in the current era, from a center with an aggressive surgical approach and a cohort with a high level of intention‐to‐treat.

Vasoreactive response to maternal hyperoxygenation in the fetus with hypoplastic left heart syndrome.

Background—Cardiopulmonary interactions play an important role in the pathophysiology of hypoplastic left heart syndrome (HLHS). Pulmonary vasculopathy has been identified, especially in those with restrictive/intact atrial septum. Responsiveness of the pulmonary vasculature to maternal hyperoxygenation (MH) may provide a tool to assess the degree of pulmonary vasculopathy present before birth. Methods and Results—Doppler echocardiography was performed in 27 normal and 43 HLHS fetuses. In HLHS, sampling was repeated after 10 minutes of MH with 60% FiO2 and after 5 minutes of recovery. Sampling was performed in the proximal, midportion, and distal branch pulmonary artery (PA). Pulsatility index (PI) was used as a measure of vascular impedance. Of the HLHS fetuses, 34 had an open interatrial septum and 9 had a restrictive/intact atrial septum. At birth, 5 fetuses underwent immediate intervention on the interatrial septum. Middle cerebral artery PI was lower in HLHS versus normal fetuses (P<0.001). There was no difference in UA, DA, or branch PA PI between normal fetuses and those with HLHS. MH led to a significant decrease in PI at each of the PA sites sampled in fetuses with an open atrial septum (P<0.001); however, there no was significant change in the PI in fetuses that required immediate intervention on the atrial septum at birth. Using a cutoff value of <10% vasoreactivity, the sensitivity of MH testing for determining need for immediate intervention at birth is 100% (0.46 to 1.0); specificity, 94% (0.78 to 0.99); positive predictive value, 71% (0.30 to 0.95); and negative predictive value, 100% (0.86 to 1.0). No untoward effects were seen with MH. Conclusions—PA vasoreactivity to MH occurs in the fetus with HLHS. MH testing accurately identifies fetuses requiring urgent postnatal intervention at birth and may be used to select candidates for fetal atrial septoplasty.

Right Ventricular Performance in the Fetus With Hypoplastic Left Heart Syndrome

BACKGROUND In the fetus with hypoplastic left heart syndrome (HLHS), the single right ventricle (RV) pumps the entire cardiac output in utero. By investigating RV performance in utero, we sought to determine the inherent capabilities of a single RV before the increased metabolic demands of postnatal life and surgical palliation. In addition, we sought to determine whether the presence or absence of a left ventricular cavity impacts on RV performance in fetal life. METHODS Between November 2004 and December 2006, Doppler flow-derived measures of ventricular performance were obtained with echocardiography in 76 fetuses with normal cardiovascular system and in 48 age-matched fetuses with HLHS from 17 weeks until 40 weeks of gestation. The myocardial performance index, ventricular ejection force, and cardiac output were determined for both groups and compared using unpaired Students t tests and regression analysis. RESULTS In fetuses with HLHS, cardiac output was diminished by 20%, RV ejection force was elevated, and RV myocardial performance index was elevated compared with those of normal fetuses. The presence of a left ventricular cavity did not impact on RV performance in utero. CONCLUSIONS Fetuses with HLHS have preserved systolic performance but impaired diastolic performance compared with normal fetuses. The heart of a fetus with HLHS is less efficient than the normal heart in that ejection force of the RV is increased, but overall delivery of cardiac output is lower than normal. We conclude that patients with HLHS have inherent limitations in cardiac performance even before birth.

Impact of altered loading conditions on ventricular performance in fetuses with congenital cystic adenomatoid malformation and twin-twin transfusion syndrome

In the fetus with a structurally normal heart, two conditions—giant chest mass, such as congenital cystic adenomatoid malformation (CCAM), and twin–twin transfusion syndrome (TTTS)—alter ventricular loading conditions and may result in cardiovascular compromise. The aim of this study was to elucidate the mechanism of cardiovascular dysfunction by comparing geometry‐independent, Doppler flow‐derived measures of ventricular performance in fetuses with altered loading conditions vs. those in normal fetuses.

The association of fetal cerebrovascular resistance with early neurodevelopment in single ventricle congenital heart disease

BACKGROUND Children with congenital heart disease are at risk for impaired neurodevelopment (ND). We investigated the association of fetal cerebrovascular resistance with ND in patients with single ventricle lesions. METHODS In the Single Ventricle Reconstruction (SVR) and Infant Single Ventricle trials, 14-month ND was assessed using the Bayley Scales of Infant Development II. We investigated associations between ND scores and fetal middle cerebral artery pulsatility index (MCA-PI) z-scores, a Doppler-derived estimate of cerebrovascular resistance in a subset of those infants. RESULTS Neurodevelopment assessments were performed at age 14.3 ± 1 months in 170 (74%) of 230 Infant Single Ventricle and 321 (58%) of 555 SVR subjects. Fetal echocardiographic data were available in 119 subjects, 72 (61%) of which had ND testing. Mean Psychomotor Development Index (PDI) (76 ± 20) and Mental Development Index (MDI) (89 ± 17) scores were lower than normative means (100 ± 15, P < .001). Mean MCA-PI z-score was -0.95 ± 1.52. Middle cerebral artery pulsatility index z-score correlated negatively with PDI (r = -0.27, P = .02) but was not associated with MDI. When MCA-PI z-score was added to a multivariable model controlling for factors identified in the SVR trial to predict PDI, the percentage of explained variation increased from 23% to 30%, and MCA-PI z-score remained an independent predictor (r = -3.864, P = .03). Middle cerebral artery pulsatility index z-score was not an independent predictor in a model adjusting for site. CONCLUSIONS Among fetuses with single ventricle anomalies, lower cerebrovascular resistance was associated with higher ND scores. This relationship is opposite to that observed with advanced intrauterine growth retardation and may represent a unique ability of these congenital heart disease fetuses to compensate for diminished cerebral oxygen delivery.

Comparative analysis of cerebrovascular resistance in fetuses with single‐ventricle congenital heart disease

We sought to determine whether the presence or absence of aortic obstruction impacts cerebrovascular resistance in fetuses with single‐ventricle (SV) congenital heart disease (CHD).

Outcomes and Predictors of Perinatal Mortality in Fetuses With Ebstein Anomaly or Tricuspid Valve Dysplasia in the Current Era A Multicenter Study

Background— Ebstein anomaly and tricuspid valve dysplasia are rare congenital tricuspid valve malformations associated with high perinatal mortality. The literature consists of small, single-center case series spanning several decades. We performed a multicenter study to assess the outcomes and factors associated with mortality after fetal diagnosis in the current era. Methods and Results— Fetuses diagnosed with Ebstein anomaly and tricuspid valve dysplasia from 2005 to 2011 were included from 23 centers. The primary outcome was perinatal mortality, defined as fetal demise or death before neonatal discharge. Of 243 fetuses diagnosed at a mean gestational age of 27±6 weeks, there were 11 lost to follow-up (5%), 15 terminations (6%), and 41 demises (17%). In the live-born cohort of 176 live-born patients, 56 (32%) died before discharge, yielding an overall perinatal mortality of 45%. Independent predictors of mortality at the time of diagnosis were gestational age <32 weeks (odds ratio, 8.6; 95% confidence interval, 3.5–21.0; P<0.001), tricuspid valve annulus diameter z-score (odds ratio, 1.3; 95% confidence interval, 1.1–1.5; P<0.001), pulmonary regurgitation (odds ratio, 2.9; 95% confidence interval, 1.4–6.2; P<0.001), and a pericardial effusion (odds ratio, 2.5; 95% confidence interval, 1.1–6.0; P=0.04). Nonsurvivors were more likely to have pulmonary regurgitation at any gestational age (61% versus 34%; P<0.001), and lower gestational age and weight at birth (35 versus 37 weeks; 2.5 versus 3.0 kg; both P<0.001). Conclusion— In this large, contemporary series of fetuses with Ebstein anomaly and tricuspid valve dysplasia, perinatal mortality remained high. Fetuses with pulmonary regurgitation, indicating circular shunt physiology, are a high-risk cohort and may benefit from more innovative therapeutic approaches to improve survival.

Speckle Tracking-Derived Myocardial Tissue Deformation Imaging in Twin-Twin Transfusion Syndrome: Differences in Strain and Strain Rate between Donor and Recipient Twins

Objectives: Twin-twin transfusion syndrome (TTTS) is a complex disorder with altered cardiovascular loading conditions that affects both donors and recipients. Myocardial tissue deformation analysis using vector velocity imaging is an angle-independent, speckle-tracking technique which can assess myocardial mechanics and may provide insight into cardiac dysfunction in TTTS. Methods: Digital dynamic two-dimensional four-chamber views were interrogated offline. Images were acquired utilizing standard video frame rates (30 frames/s). The global longitudinal strain, systolic strain rate, and diastolic strain rate were measured in the left (LV) and right ventricles (RV) of 25 fetal pairs with TTTS and compared to 25 gestational age-matched normal controls. Pulsatility indices for the umbilical artery and middle cerebral artery were measured. Results: The gestational age at evaluation was 20.5 ± 1.3 weeks. The donor LV systolic strain rate was higher, while the donor RV diastolic strain rate was significantly lower, than control values. The recipient longitudinal strain, systolic strain rate, and diastolic strain rate were significantly lower for both LV and RV in comparison to controls. The donor umbilical artery pulsatility index was higher than control values (1.92 ± 0.45 vs. 1.41 ± 0.25, p < 0.001), while the donor middle cerebral artery pulsatility index was lower (1.46 ± 0.28 vs. 1.87 ± 0.21). Recipient umbilical artery and middle cerebral artery pulsatility indices were no different than control values. Conclusions: In TTTS, both the donor and the recipient exhibit abnormalities of myocardial tissue deformation with ventricle-specific changes evident based on loading conditions. Donor LV systolic function is hyperdynamic due to hypovolemia and selective ejection into a low-resistance cerebrovascular circuit while the donor RV selectively ejects into a high-resistance placental circuit. Recipient RV and LV are both globally depressed with systolic and diastolic dysfunction. Further prospective validation of our findings using high frame rate analysis is indicated.

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

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.

Maternal hyperoxygenation improves left heart filling in fetuses with atrial septal aneurysm causing impediment to left ventricular inflow

Aneurysm of the atrial septum (AAS) with excessive excursion of septum primum into the left atrium is an uncommon and relatively benign fetal condition associated with impediment to left ventricular (LV) filling and the appearance of a slender, but apex‐forming, LV on fetal echocardiography. Impediment to filling can be severe, creating the image of LV hypoplasia with retrograde aortic flow. We hypothesize that maternal hyperoxygenation alters atrial septal position, improves LV filling, and normalizes aortic flow in fetuses with AAS by increasing fetal pulmonary venous return.