The American Academy of Pediatrics states that breastfeeding should be avoided for children with congenital heart disease because it requires less energy to suck from a bottle than the breast.

Choice A reason: Surgery is the definitive treatment for hypertrophic pyloric stenosis, which is a condition in which the muscle of the pylorus (the outlet of the stomach) becomes thickened and blocks the passage of food into the small intestine. The surgery, called pyloromyotomy, involves cutting the muscle to widen the opening and allow food to pass through. The surgery is usually done laparoscopically, with small incisions and a camera, and has a high success rate and low complication rate¹.

Choice B reason: Dietary restrictions are not required throughout childhood for infants with hypertrophic pyloric stenosis. After the surgery, the infant can resume normal feeding, usually within a few hours or days. The infant may have some vomiting or spitting up for a short period, but this usually resolves without any special diet.

Choice C reason: Slow feeding is not a necessary intervention for infants with hypertrophic pyloric stenosis. Slow feeding may help reduce the amount of vomiting, but it does not address the underlying problem of the pyloric obstruction. Slow feeding may also cause the infant to become frustrated, hungry, or tired. The infant should be fed according to his or her appetite and cues, and burped frequently to prevent air swallowing.

Choice D reason: Chromosomal mutation is not the cause of hypertrophic pyloric stenosis. The exact cause of this condition is unknown, but it is likely influenced by both genetic and environmental factors. Some studies have found an association between hypertrophic pyloric stenosis and certain genes, but no single gene mutation has been identified as the cause. Other risk factors include being male, firstborn, premature, exposed to certain antibiotics, or having a family history of the condition².

Choice A reason: Cardiac arrhythmia is an abnormal heart rhythm that can affect the heart's ability to pump blood. However, it is not a direct consequence of a ventricular septal defect (VSD), which is a hole in the wall between the lower chambers of the heart¹.

Choice B reason: Decreased cardiac output is the amount of blood pumped by the heart per minute. It can be reduced by a VSD, as the blood can flow back from the left ventricle to the right ventricle through the hole, instead of being pumped to the body. This can cause the infant to have cool extremities, thready pulses, and low urine output, as the tissues are not receiving enough oxygen and nutrients².

Choice C reason: Increased stroke volume is the amount of blood pumped by the heart per beat. It can be increased by a VSD, as the left ventricle has to work harder to compensate for the blood loss through the hole. However, this does not explain the infant's symptoms, as the stroke volume may not be enough to maintain a normal cardiac output².

Choice D reason: Cyanosis is a bluish discoloration of the skin and mucous membranes due to low oxygen levels in the blood. It can be caused by a VSD, as the oxygen-rich blood from the left ventricle can mix with the oxygen-poor blood from the right ventricle through the hole, and then be pumped to the body. However, this is more likely to occur in large VSDs or in infants with other heart defects that cause right-to-left shunting of blood³.