Enteral feeding in duct-dependent congenital heart disease.

BACKGROUND: Infants with duct-dependent congenital heart lesions are treated with a prostaglandin E1 infusion. We aimed to describe the feeding strategies used at our institution in such infants, and to describe the incidence of necrotising enterocolitis (NEC) in this patient group, investigating whether enteral feeding is associated with a higher risk. METHODS: Patients diagnosed with hypoplastic left heart syndrome, coarctation of the aorta, pulmonary atresia, or transposition of the great arteries born over a defined period were identified. Premature infants, those with pre-existing gastrointestinal disease, and those who never received prostaglandin were excluded. Data were compared using univariable and multivariable logistic regression models. RESULTS: A total of 177 patients were identified, of them 18 received a diagnosis of suspected or confirmed NEC. There was no association between the diagnosis of NEC and enteral feeding (P = 0.9). CONCLUSIONS: Based on these data, there does not appear to be an association between enteral feeding and NEC in infants receiving prostaglandin.

Early determinants of atherosclerosis in paediatric systemic lupus erythematosus.

OBJECTIVES: To assess traditional and non-traditional cardiovascular risk factors and to determine the prevalence and correlates of early vascular markers of atherosclerosis in paediatric systemic lupus erythematosus (pSLE). METHODS: Fifty-four adolescents with pSLE had cardiovascular risk factor assessment, disease activity and vascular testing including carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), arterial stiffness measures, and myocardial perfusion studies. RESULTS: The traditional risk factors of hypertension, elevated triglycerides, apolipoprotein B, haemoglobin A1c and insulin levels and non-traditional risk factors of elevated homocysteine and fibrinogen were present (all p<0.001). Some arterial stiffness measures, central pulse wave velocity and characteristic impedance were elevated (p<0.001), but CIMT, FMD and myocardial perfusion were normal. Cumulative prednisone dose correlated with total cholesterol (r=0.5790, p<0.001) and elevated LDL-C (r=0.4488, p=0.0012). Hydroxychloroquine treatment correlated negatively with total cholesterol (r=-0.4867, p=0.0002), LDL-C (r=-0.4805, p=0.0002) and apolipoprotein B (r=-0.4443, p=0.0011). In multivariate analysis LDL-C correlated with cumulative prednisone dose and negatively with hydroxychloroquine treatment (R2=0.40, p<0.001). CONCLUSIONS: An increased burden of traditional and non-traditional risk factors and early evidence of insulin resistance and increased central arterial stiffness were present in paediatric SLE. Disease-specific and therapy-related factors are likely modifying these cardiovascular risk profiles warranting prospective longitudinal studies.

Systemic haemodynamics in infants with vein of Galen malformation: assessment and basis for therapy.

Systemic haemodynamics in three infants with severe cardiac failure secondary to vein of Galen malformation (VGAM) were studied using two-dimensional and Doppler echocardiography. In all cases, ventricular outputs were over two times normal and superior vena caval flows up to 10 times normal reflecting high flow through the low-resistance fistula. Severe pulmonary hypertension, right heart dilatation and retrograde flow in the descending aorta were uniformly present. Systemic blood flow below the head and neck was reduced resulting in metabolic acidosis at presentation. Two infants had patent arterial ducts, in which flow was entirely right to left and on entering the aorta passed predominantly retrogradely towards the VGAM. These findings provide a basis for understanding the pathophysiology of cardiac failure in VGAM and support treatment with pulmonary and systemic vasodilating agents.

Remote ischaemic preconditioning protects against cardiopulmonary bypass-induced tissue injury: a preclinical study.

OBJECTIVES: To test the hypothesis that remote ischaemic preconditioning (rIPC) reduces injury after cardiopulmonary bypass (CPB). DESIGN: Randomised study with an experimental model of CPB (3 h CPB with 2 h of cardioplegic arrest). Twelve 15 kg pigs were randomly assigned to control or rIPC before CPB and followed up for 6 h. INTERVENTION: rIPC was induced by four 5 min cycles of lower limb ischaemia before CPB. MAIN OUTCOME MEASURES: Troponin I, glial protein S-100B, lactate concentrations, load-independent indices (conductance catheter) of systolic and diastolic function, and pulmonary resistance and compliance were measured before and for 6 h after CPB. RESULTS: Troponin I increased after CPB in both groups but during reperfusion the rIPC group had lower concentrations than controls (mean area under the curve -57.3 (SEM 7.3) v 89.0 (11.6) ng.h/ml, p = 0.02). Lactate increased after CPB in both groups but during reperfusion the control group had significantly more prolonged hyperlactataemia (p = 0.04). S-100B did not differ between groups. Indices of ventricular function did not differ. There was a tendency to improved lung compliance (p = 0.07), and pulmonary resistance changed less in the rIPC than in the control group during reperfusion (p = 0.02). Subsequently, peak inspiratory pressure was lower (p = 0.001). CONCLUSION: rIPC significantly attenuated clinically relevant markers of myocardial and pulmonary injury after CPB. Transient limb ischaemia as an rIPC stimulus has potentially important clinical applications.

Non-invasive assessment of ventricular force-frequency relations in the univentricular circulation by tissue Doppler echocardiography: a novel method of assessing myocardial performance in congenital heart disease.

OBJECTIVE: To describe the first clinical application of a novel tissue Doppler derived index of contractility, isovolumic acceleration (IVA), in the assessment of the ventricular myocardial force-frequency relation (FFR) in the univentricular heart (UVH). DESIGN: Prospective study. SETTING: Tertiary referral centre. INTERVENTIONS: Non-invasive assessment of the myocardial FFR by tissue Doppler echocardiography during atrial pacing. RESULTS: IVA was used to measure the FFR of the systemic ventricle in patients with structurally normal hearts and in patients with UVHs. Basal IVA of the normal hearts (mean (SD) 1.9 (0.3) m/s2) was significantly greater than that of UVHs in patients with a dominant right ventricle (RV) (1.0 (0.3) m/s2) or left ventricle (LV) (0.8 (0.7) m/s2; p < 0.05 for both). Neither the absolute nor percentage change from basal to peak values of IVA with pacing differed between the three groups. Peak force developed by the normal LV was significantly greater than that of the UVH, dominant LV group but not different from that of the UVH, dominant RV group. CONCLUSION: Contractility at basal heart rate is depressed in patients with UVH compared with the normal LV. Analysis of ventricular FFRs exposes further differences in myocardial contractility. There is no evidence that contractile function of the dominant RV is inferior to that of the dominant LV over a physiological range of heart rates.

Long term somatic growth after repair of tetralogy of Fallot: evidence for restoration of genetic growth potential.

OBJECTIVE: To compare actual with predicted long term growth after early repair of tetralogy of Fallot (TOF). DESIGN: Serial preoperative and postoperative anthropometric data were converted with z scores. The presence of restrictive physiology was assessed by echocardiography. PATIENTS: 45 otherwise healthy patients who underwent repair at median age 1.6 years (range 0.2-4.9) were studied. Predicted height was determined from mid-parental height corrected for sex. RESULTS: Mean (SD) weight and height z scores at the time of surgery were significantly depressed (-1.04 (0.82) and -0.93 (0.95), respectively; p < 0.0001 for both). At latest follow up at a median age of 14.2 years (range 11-20.5), mean weight and height z scores were 0.16 (1.1) and -0.05 (0.81) (p = 0.32 and p = 0.41, respectively). The improvement between surgical and late weight and height z scores was significant (p < 0.0001 for each comparison). Catch up growth was largely complete within two years. Age at correction, duration of follow up, and prior surgical procedures were unrelated to growth. Mean current height z scores were similar to those predicted by mid-parental height. Patients with restrictive right ventricular physiology (n = 24) had a significantly greater late z score for weight (0.49 v -0.34; p = 0.01), with a similar trend for height. Low birth weight patients experienced comparable catch up growth but remained shorter than patients with normal birth weight (mean height z score -0.64 v 0.06; p = 0.03). CONCLUSIONS: Early repair of TOF results in significant acceleration of weight and height, with normalisation of long term growth and fulfilment of genetic growth potential.