Why does congenital heart disease cause failure to thrive?

Abstract

SUMMARY Metabolisable energy intake, determined by bomb calorimetry of food, vomit, stool and urine, and resting metabolism, assessed by respiratory gas exchange, were studied in 21 infants with congenital heart disease and nine control infants. Weight for age, growth rates, and daily metabolisable energy intake per kg tended to be lower in infants with heart disease than in control infants. Resting oxygen consumption was high in those infants with pulmonary hypertension and persistent cardiac failure. Energy intake, as a percentage of that recommended for age, correlated with weight gain, and resting oxygen consumption correlated inversely with both percentage body mass index and relative fatness. Failure to thrive in infants with congenital heart disease may be due to a combination of low energy intakes and, in some cases, high energy requirements allowing insufficient energy for normal growth. Increasing the energy intakes of infants with congenital heart disease may be a way of improving their growth.Many children with congenital heart disease are small.' Their failure to thrive usually dates from early infancy, and postmortem studies suggest infants dying with congenital heart disease and failure to thrive are malnourished.2 There are several possible explanations for this: hypoxia and breathlessness may lead to feeding problems; anoxia or venous congestion of the bowel may result in malabsorption; peripheral anoxia and acidosis may lead to inefficient utilisation of nutrients; and increased metabolic rate may mean that recommended energy intakes are insufficient for normal growth and nutrition.Many of the studies investigating failure to thrive and congenital heart disease review children over wide age ranges.1 3 The findings in children of school age or adolescents will not necessarily indicate causes of poor growth that date from infancy. We have compared total energy intake, metabolisable energy intake (total energy ingested minus energy losses in stool, urine, and vomit), resting oxygen consumption, and growth rates of infants with congenital heart disease and normal infants to try to determine the causes of failure to thrive in infants with congenital heart disease.

Decreased serum insulin-like growth factor-I associated with growth failure in newborn lambs with experimental cyanotic heart disease.

“…In this circumstance, surgical repair is usually delayed until the infant reaches a specified weight, yet the adverse effects ofchronic hypoxemia on growth make this a difficult goal to achieve. Although there have been several previous investigations to determine the etiology of growth failure during chronic hypoxemia, the exact mechanisms are still not well defined (5)(6)(7)(8)(9)(10). Hypermetabolism (5,6), reduced visceral blood flow (1 1), tissue hypoxemia (12), reduced caloric intake (1,12), abnormalities in digestive enzymology (13)(14)(15)(16), and alterations in growth hormone and insulin metabolism (17,18) have been proposed as etiologies.…”

“…Although there have been several previous investigations to determine the etiology of growth failure during chronic hypoxemia, the exact mechanisms are still not well defined (5)(6)(7)(8)(9)(10). Hypermetabolism (5,6), reduced visceral blood flow (1 1), tissue hypoxemia (12), reduced caloric intake (1,12), abnormalities in digestive enzymology (13)(14)(15)(16), and alterations in growth hormone and insulin metabolism (17,18) have been proposed as etiologies. However, previous studies in infants and children with cyanotic congenital heart disease have been complicated by difficulties in controlling for the multiple variables present in the clinical setting (6,8,(19)(20)(21)(22)(23).…”

Nutritional Approach of Pediatric Patients Diagnosed with Congenital Heart Disease

“…Authors like Jackson and Poskitt have proposed supplementing formula or breast milk with glucose polymers, increasing mean energy intake by 31.7% and resulting in a weight gain improvement from 1.3 g/kg/day in controls to 5.8 g/kg/day with high energy feeding [20]. Th is method has its drawbacks, because another study found that feeding malnourished children high-energy formula may stimulate greater diet-induced thermogenesis and increase metabolic ineffi ciency, canceling some of the positive eff ect [12]; for these children it can also be diffi cult to tolerate the concentrated glucose, thereby they need close monitoring.…”

“…Th is is explained by the decreased caloric intake and greater energy expenditure encountered in these children, having in consequence less energy available for fat deposition. Th e increased percentage of lean body mass tends to increase the basal metabolic rate [12], further increasing metabolic rate, which, if left untreated, can dramatically worsen the child's overall health status.…”

Defining Fluid Restriction in the Management of Infants Following Cardiac Surgery and Understanding the Subsequent Impact on Nutrient Delivery and Growth Outcomes

“…When provided supplemental feedings via a gastric tube, infants demonstrated weight gain indicating that infants with CHD grow when their energy requirement are met (Bougle, Iselin, Kahyat, & Duhamel, 1986;Krieger, 1970). Investigations into malabsorption as a potential factor for FTT has not revealed significant differences in energy loss via stool when comparing infants with CHD to healthy infants (Menon & Poskitt, 1985;Vaisman et al, 1994;van der Kuip et al, 2003).…”