Aparna Kulkarni

Outcomes and risk factors for listing for heart transplantation after the Norwood procedure: An analysis of the Single Ventricle Reconstruction Trial

BACKGROUND Infants with hypoplastic left heart syndrome after palliation have the worst survival among heart transplant recipients. Heart transplantation is often reserved for use in patients with sub-optimal results after palliative surgery. This study characterized outcomes after listing in infants with a single ventricle who had undergone the Norwood procedure and identified predictors of the decision to list for heart transplantation. METHODS The public-use database from the multicenter, prospective randomized Single Ventricle Reconstruction trial was used to identify patients who were listed for heart transplantation. Outcomes on the waiting list and after transplantation were determined. Risk factors were compared between those who were listed and those who survived without listing. RESULTS Among 555 patients, 33 patients (5.9%) were listed and 18 underwent heart transplantation. Mortality was 39% while waiting for a heart and was 33% after heart transplantation. Overall, 1-year survival after listing (including death after transplantation) was 48%. Factors associated with listing were a lower right ventricular fractional area change at birth, non-hypoplastic left heart syndrome diagnosis, and a more complicated post-Norwood course, defined as a higher need for extracorporeal membrane oxygenation, longer intensive care unit stay, more complications, and a higher number of discharge medications. CONCLUSIONS Worse right ventricular function, non-hypoplastic left heart syndrome diagnosis, and complex intensive care unit stay were significant risk factors for listing for heart transplantation after the Norwood procedure. Heart transplantation as a rescue procedure after the Norwood procedure in the first year of life carries a significant risk of mortality.

Fetal Myocardial Deformation in Maternal Diabetes Mellitus and Obesity.

Experimental evidence suggests that changes in the fetal myocardium result from intrauterine effects of maternal diabetes mellitus and obesity. The aim of this study was to assess fetal cardiac function using two‐dimensional speckle‐tracking echocardiography to determine the effects of maternal diabetes and obesity on the fetal myocardium.

Lack of Association of ST–T Wave Abnormalities to Congenital Heart Disease in Neonates

BACKGROUND ST-T wave (STTW) abnormalities have been described in 20-40% of normal newborns. We sought to describe the associations of these Electrocardiogram (ECG) abnormalities to perinatal course and congenital heart disease (CHD). METHODS A retrospective chart review was performed on all neonatal ECGs between January 2008 and March 2013 identified from electronic medical records. Electronic medical records were reviewed for perinatal course and maternal medical conditions. Neonates <37 weeks gestation, >3 days age, requiring hemodynamic support in the first 3 days, with oxygen saturation <90% on room air, or with arrhythmias and significant abnormalities of axis and voltage were excluded from the analysis. ST segment elevation or depression of >2 mm in at least one lead and flat or inverted T waves in at least one lead except aVR were considered abnormal. Statistical relationships were explored between STTW abnormalities, perinatal variables and CHD. RESULTS ECGs were performed on 1043 neonates, of which 664 were included. STTW abnormalities were found in 236 (35.5%) neonates. T wave abnormalities were identified in 191 (28.7%), ST segment abnormalities in 77 (11.6%) and both on 32 (4.8%) neonates. No relationship was found between the ECG abnormalities and perinatal variables, except maternal cefazolin administration during labor. Noncritical CHD was diagnosed by echocardiography in 59/84; STTW abnormalities were seen in 17/59 (29%) patients with and 9/25 (34%) without noncritical CHD, P = .6. CONCLUSION STTW abnormalities on ECG are commonly found in 35.5% of normal neonates and do not predict noncritical CHD.

Remodeling of the cardiovascular circulation in fetuses of mothers with diabetes: A fetal computational model analysis

AIMS Myocardial structural and functional abnormalities are known to occur in fetuses of mothers with diabetes mellitus (FMDM). The main aim of this investigation was to explore the cardiovascular circulatory patterns in FMDM using a validated lumped computational model of the cardiovascular system. METHODS This was a multi-institutional study involving FMDM compared to fetuses of maternal controls (FC). Fetal echocardiographic Doppler data from left and right ventricular outflow tracts, aortic isthmus, middle cerebral and umbilical arteries were fitted into a validated fetal circulation computational model to estimate patient-specific placental and vascular properties. Non-parametric comparisons were made between resistances, compliances and flows in the brain and placenta in FMDM and FC. RESULTS Data from 23 FMDM and 31 FC were fitted into the model. In FMDM, compared to FC, placental relative resistance was lower (0.59 ± 0.50 versus 0.91 ± 0.41; p < .05) with higher brain relative resistance (2.36 ± 1.65 versus 1.60 ± 0.85; p < .05). Middle cerebral artery flow was lower in FMDM than FC (0.12 ± 0.14 vs. 0.27 ± 0.21 ml/min; p 0.04) with a lower cerebral-placental flow ratio. Combined stroke volume was lower in FMDM (3.65 ± 2.05 ml) than FC (4.97 ± 2.45 ml) (p 0.04). CONCLUSIONS Blood flow is redistributed in FMDM to the placenta, away from the brain. This alteration may play a role in the postnatal health of these fetuses.

Depressed left and right ventricular cardiac output in fetuses of diabetic mothers

Introduction We compared right and left ventricular cardiac output (RVCO and LVCO) in fetuses of diabetic mothers (FDM) with a large normal cohort. Methods We prospectively enrolled 264 normal fetuses and 30 FDM. Fetal CO parameters such as semilunar valve velocity time integrals (AVVTI, PVVTI), ventricular outflow diameters (LVOTD, RVOTD) and stroke volumes (AVSV, PVSV) were measured, and LVCO and RVCO were calculated. These were normalized using non-linear regression to estimated fetal weight (EFW) to provide means and standard deviations. Among FDMs, mean Z scores and 95% confidence limits (CL) were calculated and compared to zero. Results LVCO, RVCO and parameters they were calculated from, increased predictably and non-linearly with increasing EFW. In FDM, LVCO was depressed (mean Z −1.679, 95% CL −2.404, −0.955, P < 0.001), and AVVTI, LVOTD and AVSV were significantly lower than normal. Similarly, RVCO (mean Z = −1.119, CL −1.839, −0.400, P = 0.003), RVOTD (mean −2.085, CL −3.077, −1.093, P < 0.001) and PVSV (mean −1.184, CL −1.921, −0.446, P = 0.003) were lower than normal, however, PVVTI was not different (mean Z 0.078, CL −0.552, +0.707, P = 0.803). Conclusion Normal biventricular stroke volumes and outputs follow a non-linear regression with EFW. FDM have significantly lower right and left heart stroke volumes and outputs for weight than do normal fetuses.