Charles Rohlicek

A New Look at Outcomes of Infants With Congenital Heart Disease

This article provides an overview of a longitudinal study on a cohort of 131 newborns and young infants with congenital heart defects who required open heart surgery. The rationale for the study design is provided as well as a summary of the procedures used to evaluate these children prior to surgery, at discharge after surgery, 12-18 months later, and at 5 years of age. Results demonstrate that a substantial proportion of these infants had neurologic and developmental abnormalities prior to surgical repair. Developmental delays were common in children with both cyanotic and acyanotic heart defects, and these deficits persisted to school entry. A number of medical, surgical, demographic and environmental factors were significantly associated with developmental outcomes suggesting a multifactorial etiology to brain injury. Limited educational and rehabilitation resources for this cohort at early school age suggests that service needs may need to be more carefully planned for this high-risk population. Lessons learnt from this prospective study are highlighted as well as future directions for research and clinical practice.

Developmental and Functional Outcomes at School Entry in Children with Congenital Heart Defects

OBJECTIVE To describe developmental and functional outcomes of children with congenital heart defects (CHDs) at school entry after open heart surgery. STUDY DESIGN Infants with CHDs who underwent surgical repair in infancy were recruited and assessed prospectively for developmental progress. At 5 years of age (64.2 +/- 11.3 months), 94 subjects were evaluated in a blind fashion by using a variety of standardized measures. RESULTS Mean IQ scores were in the low average range (90-94). Receptive language was in the average range (103.6 +/- 14.4). Behavioral difficulties were common (27.1%), with internalizing problems being more frequent. Functional limitations in socialization (93.0 +/- 17.1), daily living skills (94.6 +/- 16.4), communication (90.0 +/- 14.1), and adaptive behavior (92.1 +/- 15.8) were noted in 11% to 17% of children. With the Functional Independence Measure for Children, 20% to 22% of subjects were more dependent than their peers in self-care and social cognition, although few (4.5%) had mobility restrictions. Predictors of developmental and functional limitations included: abnormal postoperative neurologic examination, microcephaly, deep hypothermic circulatory arrest time, palliation, acyanotic heart lesion, age at surgery, and maternal education. CONCLUSIONS After infant open-heart surgery, children with CHDs may exhibit a range of developmental difficulties at school entry that enhances risk for learning challenges and decreased social participation.

Health and well-being of children with congenital cardiac malformations, and their families, following open-heart surgery

Infants who survive open-heart surgery are at risk for developmental disability, which may impact on the well-being not only of the child, but also the family. The objective of our prospective study, therefore, was to determine the long-term health-related quality of life of children with congenital cardiac malformations following open-heart surgery, and to describe the persisting level of stress in their families. To this end, 49 parents completed the Child Health Questionnaire, the Parenting Stress Index, and the Child Behaviour Checklist as part of a developmental follow-up protocol when their child was 5 years of age. Mean scores on the Child Health Questionnaire were in the normal range, with physical well-being equal to 53.5, psychosocial well-being 50.9, with only 6.4 percent and 8.5 percent of subjects, respectively, falling within the suboptimal range of less than 40. The distribution of scores on the Parenting Stress Index, however, were more variable, with over one-quarter of parents indicating a high level of stress, with almost one-fifth having low levels of stress, and just over half scoring in the normal range, with the group mean being 52.6 plus or minus 32.3. An abnormal neurologic examination before surgery was associated with lower physical health (beta equal to -5.5, p equal to 0.02, r2 equal to 0.18), whereas lower arterial saturations of oxygen, less than 85 percent preoperatively, was associated with lower psychosocial health (beta equal to -6.6, p equal to 0.01, and r(2) equal to 0.14). The internalizing and externalizing behaviours of the child were significantly correlated with psychosocial well being, with r ranging from -0.32 to -0.52, and p less than 0.05. Parental stress also correlated with psychosocial health (r equal to -0.48 and p equal to 0.0009). Overall, the perception by the parents of the health-related quality of life of their child is favourable 5 years following open-heart surgery during infancy. Many parents, nonetheless, continue to feel either stressed or defensive about their child, particularly if their child exhibits behavioural difficulties. Our findings suggest that strategies need to be considered to enhance family well-being in the planning and delivery of health services to this population at high risk.

The MTHFD1 p.Arg653Gln variant alters enzyme function and increases risk for congenital heart defects.

Methylenetetrahydrofolate dehydrogenase)methenyltetrahydrofolate cyclohydrolase)formyltetrahydrofolate synthetase (MTHFD1) is a trifunctional enzyme that interconverts tetrahydrofolate (THF) derivatives for nucleotide synthesis. A common variant in MTHFD1, p.Arg653Gln (c.1958G>A), may increase the risk for neural tube defects (NTD). To examine the biological impact of this variant on MTHFD1 function, we measured enzyme activity and stability in vitro and assessed substrate flux in transfected mammalian cells. The purified Arg653Gln enzyme has normal substrate affinity but a 36% reduction in half)life at 42°C. Thermolability is reduced by magnesium adenosine triphosphate and eliminated by the substrate analog folate pentaglutamate, suggesting that folate status may modulate impact of the variant. The mutation reduces the metabolic activity of MTHFD1 within cells: formate incorporation into DNA in murine Mthfd1 knockout cells transfected with Arg653Gln is reduced by 26%±7.7% (P<0.05), compared to cells transfected with wild)type protein, indicating a disruption of de novo purine synthesis. We assessed the impact of the variant on risk for congenital heart defects (CHD) in a cohort of Quebec children (158 cases, 110 controls) and mothers of children with heart defects (199 cases, 105 controls). The 653QQ genotype in children is associated with increased risk for heart defects (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.01–4.42), particularly Tetralogy of Fallot (OR, 3.60; 95% CI, 1.38–9.42) and aortic stenosis (OR, 3.13; 95% CI, 1.13–8.66). There was no effect of maternal genotype. Our results indicate that the Arg653Gln polymorphism decreases enzyme stability and increases risk for CHD. Further evaluation of this polymorphism in folate)related disorders and its potential interaction with folate status is warranted. Hum Mutat 0,1–9, 2008.

Nuclear β-adrenergic receptors modulate gene expression in adult rat heart.

Both β(1)- and β(3)-adrenergic receptors (β(1)ARs and β(3)ARs) are present on nuclear membranes in adult ventricular myocytes. These nuclear-localized receptors are functional with respect to ligand binding and effector activation. In isolated cardiac nuclei, the non-selective βAR agonist isoproterenol stimulated de novo RNA synthesis measured using assays of transcription initiation (Boivin et al., 2006 Cardiovasc Res. 71:69-78). In contrast, stimulation of endothelin receptors, another G protein-coupled receptor (GPCR) that localizes to the nuclear membrane, resulted in decreased RNA synthesis. To investigate the signalling pathway(s) involved in GPCR-mediated regulation of RNA synthesis, nuclei were isolated from intact adult rat hearts and treated with receptor agonists in the presence or absence of inhibitors of different mitogen-activated protein kinase (MAPK) and PI3K/PKB pathways. Components of p38, JNK, and ERK1/2 MAP kinase cascades as well as PKB were detected in nuclear preparations. Inhibition of PKB with triciribine, in the presence of isoproterenol, converted the activation of the βAR from stimulatory to inhibitory with regards to RNA synthesis, while ERK1/2, JNK and p38 inhibition reduced both basal and isoproterenol-stimulated activity. Analysis by qPCR indicated an increase in the expression of 18S rRNA following isoproterenol treatment and a decrease in NFκB mRNA. Further qPCR experiments revealed that isoproterenol treatment also reduced the expression of several other genes involved in the activation of NFκB, while ERK1/2 and PKB inhibition substantially reversed this effect. Our results suggest that GPCRs on the nuclear membrane regulate nuclear functions such as gene expression and this process is modulated by activation/inhibition of downstream protein kinases within the nucleus.

Aortic baroreceptor reflex pathway: a functional mapping using [3H]2-deoxyglucose autoradiography in the rat

The organization of pathways within the central nervous system which are activated by aortic baroreceptor input was studied in the urethane anesthetized rat using the 2-deoxyglucose method. [3H]2-deoxyglucose was administered i.v. while either the aortic nerve was electrically stimulated or aortic baroreceptors were physiologically activated by pulse increases in arterial pressure in animals with bilateral denervation of the carotid sinus. Autoradiographs of transverse sections of the central nervous system were developed and analyzed for changes in metabolic activity in discrete regions compared to control animals, as indicated by the density of the photographic emulsion. Electrical stimulation of the aortic nerve resulted in all animals in an increase in the uptake of deoxyglucose in a number of sites throughout the central nervous system, primarily ipsilateral to the site of stimulation. In the brainstem, structures previously implicated in cardiovascular reflexes were labeled. These included the nucleus of the solitary tract, the solitary tract, the dorsal motor nucleus of the vagus, and the nucleus ambiguus. In addition, the inferior olivary nucleus, the parabrachial nuclei and the ventrolateral reticular formation showed increased labeling. In the hypothalamus, increased labeling was observed only in the paraventricular and supraoptic nuclei.

Cardiovascular and Respiratory Consequences of Body Warming during Hypoxia in Conscious Newborn Cats

Acute hypoxia in newborns of various species including humans is associated with decreased thermogenesis and a fall in body temperature. We have investigated the cardiorespiratory consequences of correcting the fall in colonic temperature (Tc) during acute hypoxia in newborn cats. Experiments were conducted on 21 unanesthetized kittens (12 ± 1 d SEM, 244 ± 8 g) instrumented with catheters in the left common carotid artery and superior vena cava for measurements of systemic arterial pressure, central venous pressure, heart rate, arterial blood gases, arterial O2 saturation (Sao2) and mixed venous O2 saturation. Oxygen consumption (˙Vo2) and CO2 production (˙Vco2) were also measured. Alveolar ventilation (˙Va), cardiac index (CI), and systemic vascular resistance index (SVRI) were calculated. These determinations were made in 21% O2 at an ambient temperature (Tamb) of 25 °C, and after 80 min of exposure to Fio2 = 0.10. In one group Tamb was maintained at 25 °C (n = 8) during hypoxia and Tc fell by 2.7 ± 0.4 °C whereas in a second group Tamb was increased to 35°C for the second 40 min of hypoxia to raise Tc to the prehypoxic level(n = 13). ˙Vo2, ˙Vco2, ˙Va, Sao2, and systemic arterial pressure during hypoxia did not differ between the animals which were warmed and those which were not. However, CI and heart rate were greater (452 ± 23 versus 346 ± 30 mL·min-1·kg-1 p < 0.05, 279 ± 8versus 228 ± 12 beats·min-1 p < 0.05) and SVRI lower (0.115 ± 0.022 versus 0.153 ± 0.014 mm Hg·mL-1·min·kg, p < 0.05) during hypoxia in the warmed animals compared with the unwarmed group. Thus, artificially raising Tc during hypoxia resulted in peripheral vasodilatation, whereas systemic arterial pressure was maintained by the increase in cardiac output. We conclude that, in the hypoxic kitten, raising Tc to normoxic values elicits a response that may reflect a condition of relative hyperthermia.

Attitudes and Practices of Cardiologists and Surgeons Who Manage HLHS

OBJECTIVE: We conducted a survey to determine which management options pediatric cardiologists and cardiac surgeons in North America discuss and recommend when counseling parents after the diagnosis of hypoplastic left heart syndrome (HLHS). METHODS: Pediatric cardiologists and cardiac surgeons across North America were asked to complete an anonymous, Internet-based survey about their attitudes and practices regarding the management of HLHS. RESULTS: We contacted 1621 pediatric cardiologists and surgeons, of whom 749 (46%) completed the survey. When counseling parents of newborns with HLHS, 99.7% of respondents discussed staged palliative surgery, 67% discussed cardiac transplantation, and 62.2% discussed compassionate care without surgery. Only a minority (14.9%) discussed all of those options. Staged palliative surgery was recommended over cardiac transplantation or compassionate care without surgery by 76.2% of respondents. When counseling parents after prenatal diagnosis of HLHS, 98.8% of respondents discussed continuation of pregnancy with staged palliative surgery after birth, 53.5% discussed continuation of pregnancy with cardiac transplantation after birth, 56.9% discussed continuation of pregnancy with compassionate care after birth, and 74.3% discussed termination of pregnancy. Only 36.5% discussed all of those options. Continuation of pregnancy with staged palliative surgery after birth was recommended over the other options by 56% of respondents. CONCLUSIONS: Virtually all North American pediatric cardiologists and cardiac surgeons surveyed discuss a surgical intervention when counseling parents about the care of their child or fetus with HLHS. However, only a minority discuss all options. Most physicians recommend staged palliative surgery for management of HLHS.

Association Between Electroencephalographic Findings and Neurologic Status in Infants With Congenital Heart Defects

Neurologic status is of concern in infants with congenital heart defects undergoing open heart surgery. The association between perioperative electroencephalography (EEG) with acute neurologic status and subsequent outcome was examined in a cohort of 60 infants. Preoperative EEG and neurologic examinations were performed within 1 to 2 days prior to surgery (n = 27) and postoperatively (n = 47). Prior to surgery, 15 of 27 infants had normal EEG, whereas 5 had epileptiform activity and 9 had disturbances in background activity that were primarily moderate (8/9) and diffuse (7/9). Postoperatively, only 17 of 47 infants had normal recordings. Newborns (<1 month) were more likely (P < .001) to demonstrate EEG abnormalities than infants. Epileptiform activity was documented in 15, whereas 28 had background abnormalities that were moderate-severe (22/28) and diffuse (20/28) in most. Epileptiform activity prior to surgery was always associated with an abnormal neurologic examination, and this association persisted postoperatively (86%). Moderate to severe background abnormalities in the postoperative EEG was also strongly associated with acute neurologic abnormalities (93%). Severe background abnormalities (n = 5) were 100% predictive of death or severe disability. Long-term follow-up revealed that all children with normal postoperative EEGs had positive neurologic outcomes (P = .04); however, there were many false positives. Perioperative EEG abnormalities increased the likelihood for acute neurologic findings, whereas normal recordings following surgery were reassuring with regard to a favorable outcome. (J Child Neurol 2001;16:471-476).

Primary repair minimizing the use of conduits in neonates and infants with tetralogy or double-outlet right ventricle and anomalous coronary arteries.

OBJECTIVE The purpose of this study was to review our results with an approach of early primary repair for tetralogy of Fallot or double-outlet right ventricle with anomalous coronary arteries, using several techniques to minimize the use of a conduit. METHODS Twenty consecutive neonates and infants with anomalous coronary arteries crossing an obstructed right ventricular outflow tract underwent primary repair. Median age was 5.5 months and mean weight 6.22 kg. The anomalous coronary arteries included the left anterior descending from the right coronary artery (n = 10), the right coronary artery from the left anterior descending (n = 1), the left anterior descending from the right sinus (n = 1), and a significant conal branch from the right coronary artery (n = 7) or left anterior descending (n = 1). Two neonates had pulmonary atresia. The right ventricular outflow tract was reconstructed without a conduit in 18 patients, including those with pulmonary atresia. Surgical techniques included main pulmonary artery translocation in 4 patients, transannular repair under a mobilized left anterior descending coronary artery in 2 patients, and displaced ventriculotomy with subcoronary suture lines in 8 patients. In 4 patients the right ventricular outflow tract was repaired via the ventriculotomy and/or pulmonary arteriotomy. A homograft was used as the sole right ventricle-pulmonary artery connection in 1 patient and in another a homograft was added to a hypoplastic native pathway. RESULTS There have been no early or late deaths. The right ventricular/left ventricular pressure ratio within 48 hours of the operation was 0.47 +/- 0.10. There were 2 reoperations at 8 and 11 years after the operation, during a mean follow-up of 5.2 years (1-11.3 years). CONCLUSIONS Primary repair of tetralogy of Fallot or double-outlet right ventricle with anomalous coronary arteries can be done in neonates and infants with excellent results. Alternative surgical techniques for right ventricular outflow tract reconstruction, such as main pulmonary artery translocation, can avoid the use of a conduit in most patients.