M. McCann

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.

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).

Anatomic variability and outcome in prenatally diagnosed absent pulmonary valve syndrome.

BACKGROUND We sought to describe current outcomes and risk factors for mortality for fetuses diagnosed with absent pulmonary valve syndrome (APV). Fetuses with APV were divided into two cohorts, those with underlying tetralogy of Fallot (TOF/APV) and those without underlying TOF and either an intact ventricular septum or small ventricular septal defect (APV/IVS). METHODS The fetal echocardiographic database was reviewed from January 1, 2001, until June 1, 2010, and all subjects with a diagnosis of APV were included. Multiple clinical and fetal echocardiographic measurements were recorded. Statistical analysis was performed by χ2 analysis and t tests. Survival analysis was performed by Kaplan-Meier analysis. Significant relationships between variables were explored by regression analysis. Significance was set at p=0.05. RESULTS The cohort consisted of 15 fetuses with TOF/APV and 6 fetuses with APV/IVS. There were no fetal demises in either cohort. Survival to birth was 71% in the TOF/APV cohort and 83% in the APV/IVS cohort (p=0.62). Of subjects born alive, survival was 80% for both cohorts (p=0.95). However, in the APV/IVS cohort, transplantation-free survival was only 20%. Underlying single-ventricle physiology strongly predicted those who underwent heart transplantation (p=0.003, R2=0.50). For the entire APV cohort, left ventricular dysfunction (p=0.005, R2=0.41) and a higher pulmonary artery valve-to-aortic valve ratio (p=0.02, R2=0.34) predicted mortality. CONCLUSIONS Postnatal outcomes continue to improve for fetuses with APV syndrome. Left ventricular dysfunction and higher pulmonary artery valve-to-aortic valve ratio accurately predict postnatal mortality for fetuses with APV.

Utility of a Single 3-Vessel View in the Evaluation of the Ventricular Outflow Tracts

Prenatal diagnosis of congenital heart disease can improve neonatal outcomes. The purpose of this study was to evaluate the utility of an isolated 3‐vessel view image in evaluating the ventricular outflow tracts.

Fetal cardiovascular effects of lower urinary tract obstruction with giant bladder

Lower urinary tract obstruction (LUTO) with massive bladder distension impacts on a variety of developing organ systems with consequent morbidity and mortality. The impact of LUTO on the fetal cardiovascular system has not previously been investigated. We hypothesize that a giant, distended bladder within the pelvis may cause vascular compression with observable consequences.

Pulmonary artery blood flow patterns in fetuses with pulmonary outflow tract obstruction.

Fetuses with pulmonary outflow tract obstruction (POTO) have altered blood flow to the pulmonary vasculature. We sought to determine whether pulmonary vascular impedance, as assessed by the pulsatility index (PI), is different in fetuses with POTO compared with normal controls.

OC109: Prominence of the coronary circulation in the fetus: a prognostic indicator of poor outcome?

described and the frequency with which muscular VSDs resolve in utero has also not been extensively reported. Methods: We investigated the perinatal course of isolated muscular VSDs diagnosed and followed between 1 January 2005 and 31 December 2006. Results: We performed a total of 2583 fetal echocardiograms on 2410 fetuses during 2328 pregnanies. The study group included 78 twin gestations (3.4%) and seven triplet gestations (0.3%). There were 16 diagnoses of isolated muscular VSD (6.6/1000). Mean ± SD gestational age at diagnosis was 24.5 ± 4.9 weeks. Two of the isolated muscular VSDs (12.5%) spontaneously resolved prenatally. One fetus had trisomy 21. Conclusions: Isolated VSD is a common congenital heart defect. Resolution of prenatally diagnosed isolated muscular VSDs is less frequent than reported in the past. Trisomy 21 risk may be increased in isolated muscular VSDs even in the absence of other ultrasound markers. A larger cohort is needed to provide a better risk estimate for aneuploidy in the presence of an isolated VSD.

OC108: Ventricular performance in the fetus with hypoplastic left heart syndrome

DOI:€10.1016/j.athoracsur.2008.11.032 Ann Thorac Surg 2009;87:1214-1219 Anita Szwast, Zhiyun Tian, Margaret McCann, Denise Donaghue and Jack Rychik Syndrome Right Ventricular Performance in the Fetus With Hypoplastic Left Hearthttp://ats.ctsnetjournals.org/cgi/content/full/87/4/1214 located on the World Wide Web at: The online version of this article, along with updated information and services, is