Cardiac Failure and Congenital Heart Disease in Pediatric

Congenital heart disease may present as heart failure with or without shock or cyanosis. However, there are many causes of cardiac failure, including non-congenital reasons such as myocarditis. These may present with signs of heart failure, such as breathlessness, hepatomegaly, pallor and sweating, or may be severe enough to present as cardiogenic shock. Remember that heart failure in an infant can mimic bronchiolitis and the child may have contracted bronchiolitis. This in turn may be the precipitating cause of the heart failure. The likely causes are in picture below.

Causes of Cardiac Failure in Pediatric

In infancy heart failure is usually secondary to congenital structural heart disease. As pulmonary pressures reduce after birth over the first few hours to days of life, increased pulmonary flow from lesions such as VSD or PDA will become apparent. These infants are likely to have a cardiac murmur audible. Rarer duct-dependent lesions, such as pulmonary atresia or transposition of the great vessels, will also present after a few days to weeks as the duct closes. These infants may have a large liver but may not have a cardiac murmur audible. Coarctation and severe aortic stenosis will also present as the duct closes.

Investigation

• CXR may be helpful to demonstrate cardiomegaly with pulmonary plethora or a

characteristic cardiac shape and size

• 12-lead ECG

• Cardiac echocardiography and cardiac consultation

• Infection screen as above

• 4-limb blood pressure

Management Shock 

If there are signs of shock then treat as in the cardiogenic shock section. Heart failure If the ventilation is adequate, then oxygen by facemask will be sufficient. However, if breathing is inadequate, intubation and artificial ventilation with PEEP will be required. 

If oxygenation improves with this maneuver, then the likely problem is that of pulmonary congestion secondary to increased flow from a VSD or PDA etc. A heart murmur may be heard and chest X-ray might be helpful in confirming the diagnosis (see below).

Treatment needs to be discussed with the cardiologists. It will include oxygenation and reducing the preload with diuretics (with, for example, frusemide 1 mg/kg i.v., repeated if no response after 2 hours). Consideration will be given to improving cardiac contractility (using, for example, digoxin or inotropes, such as dopamine or dobutamine) or decreasing the afterload with vasodilatation (using, for example, captopril).

Cyanosis

Increasing breathlessness and cyanosis in the first few days of life is the presentation of the rarer duct-dependent disease, such as tricuspid or pulmonary atresia. In theseconditions, oxygen may cause the duct to close further but, if it is considered necessary for ventilation, it should be carefully titrated. Intravenous prostaglandin El (0.01–0.1 µg/kg per min) should keep the duct open until cardiac opinion is available. Once aresponse occurs, the infusion rate should be titrated down. Prostaglandins may causeapnea and so the child should be ventilated during its administration.

All these children require careful monitoring by ECG, pulse oximetry and non-invasive blood pressure measurement. Remember to check blood pressure in lower limbs as well as upper limbs. It is essential to consider sepsis as a differential diagnosis of cardiacfailure in infancy and most infants will require a full infection screen and possible antibiotic cover. These children need admission and assessment by the cardiology team.