What is heart failure?

Heart failure is a condition where the heart is unable to meet the body’s needs. Heart consists mainly of muscles which move on electrical signals from our intrinsic electrical battery. Heart works as a pump in our body to ensure adequate oxygen and nutrient-rich blood delivery to our body’s cells. In short, heart failure means that the heart is not pumping as well as it should be.

How do you identify heart failure in children?

There is a spectrum of clinical presentations of heart failure in children. Children with heart failure are not necessary to ’turn blue’. There are many heart conditions that can cause children to have heart failure but still appear ‘pink’. However, if a child appears ‘blue” with the following discussed features, the possibility of this child to have heart failure is higher.
You should consider heart failure in a baby with rapid breathing at rest, excessive sweating with feeding, prolonged feeding time and poor weight gain .Abnormal heart sound and rapid heart beat are common findings in this group of children. They are always describe as difficult babies as they are always restless and irritable,
Older children with heart failure may also have rapid breathing at rest but more noticeable after physical activities. They are not as active as their peers and tire easily. They also have rapid heart rate with poor weight gain. They often have recurrent chest infection and abnormal heart sound. Very rarely, they may have leg and body swelling as well.
In acquired causes of heart failure, there may be associated fever, pale appearance and skin rashes.

What causes heart failure in children?

The causes of heart failure in children differ from those found in the adult population.
Congenital heart disease is the main cause of heart failure in children. Congenital heart disease is a heart problem that a baby is born with. The abnormal heart structure in congenital heart disease may interfere with the normal heart function causing increase in heart’s workload, of which leads to heart failure
Any condition which causes poor heart muscle function also contributes to the inefficiency of the heart pumping mechanism. This condition may occur following viral infection or caused by genetic abnormality.
The causes of heart failure in children can further be divided into 3 major categories.

• Volume overload heart failure:
  This is a condition where there is an increased in the blood volume load of the heart .The excess volume cause the heart to work extra hard. Simultaneously, the body produces hormonal changes in response to the volume change that added further stress on the heart.
  To illustrate this, few examples with this type of heart failure are as follows.
  • Large Ventricular Septal Defect- This is a heart problem where a child is born with a large hole in the heart which allows a communication between the lower left and right heart chambers. There is an abnormal blood flow from the left chambers into the right. This unbalance volume load in the right heart chambers and a decreased volume in the left chambers, make heart pumps faster and works extra hard. The lung which receives blood from the right heart chambers is later flooded with blood and cause a child to have rapid breathing.
  • Severe valve regurgitation-Valve is a ‘door’ in the heart which ensures one-way blood flow. There are 4 valves in the heart. Regurgitation is an abnormal valve movement manifested as reverse blood flow into the respective heart chambers. Regurgitation leads to heart chambers dilatation and impaired function. Severe valve regurgitation in children can be found in both congenital heart and acquired disease such as in Ebstein‘s Anomaly (congenital) and in rheumatic heart disease (acquired).
• Pressure overload failure:
  This is a condition where there is an obstruction in the blood flow pathway both in and/or outside the heart .When this happens; the heart muscle will work hard to push blood across the obstruction. This creates high pressure in the affected heart chambers. Ongoing insults will lead to thickening of heart muscle and followed by a deprivation in oxygen supply to the affected heart inner surface and muscle. In the long run, the affected heart structure will fail to maintain its function.

  To illustrate this, below is an example of this type of heart failure.

  • Severe Aortic Stenosis- Aortic valve is a ‘door’ which controls outflow of blood from the left heart chambers. Stenosis and obstruction in this context is interchangeable. In severe aortic valve obstruction, the left ventricle works hard to push blood across this narrow opening. With time, the left ventricle becomes thickened and enlarged. If left untreated, the left ventricle will fail leading to heart failure.
• Pump failure:
  This is a condition where heart muscle is not functioning normally (cardiomyopathy).  The heart structure is usually normal. This condition may occur following genetic abnormality (Primary cardiomyopathy) or following viral infections, abnormal heart rhythm, drug toxicity and exposure to severe lack of oxygen.

How is heart failure diagnosed?

Your doctor will usually ask you history particularly on your child’s feeding habits, activities, family history of heart disease and perform the relevant physical examination. Heart failure can usually be diagnosed by clinical judgment alone.

Tests like chest radiograph (chest X-ray) and electrocardiogram (ECG) may support heart failure diagnosis and give clue on the underlying cause.  Chest x-ray in heart failure children will show an enlarged heart with congested lungs. ECG shows heart rhythm and highlights on area with thickened heart muscle.

Other test to look for underlying heart disease is echocardiography. This is an ultrasound examination of the heart usually done by cardiologist. Mostly all congenital heart defects can be identified using this test. It also allows the cardiologist to assess your child’s heart function.

How to treat heart failure?

Having heart failure is not the end of the world. The treatment of heart failure can be divided into symptomatic treatment (making your child feels better) and treating the underlying heart condition.

Symptomatic treatment includes

• Medication
  • Diuretics – Medication to help your child reduce the amount of volume that enters his /her heart. The fluid is passed out from the body as urine. These medications decrease pulmonary congestion and reduce breathing difficulties. Example: frusemide and aldactone.
  • Angiotensin-converting enzyme (ACE) inhibitor –Medication to help your child reduce the heart workload and ensure better blood delivery to the body. This medication is not suitable in pressure overload heart failure .Example: captopril.
  • Digoxin –Medication to improve heart contractility.
• Nutritional supports to optimize growth.
• Oxygen when needed
• Treating infection and immunization

Treating the underlying heart condition

• Surgery –To correct the underlying structural defect (in suitable lesions).
• Cardiac catheterized intervention-A catheter based procedure to alleviate heart obstruction (in suitable lesions).
• Pacemaker – External device to treat severe abnormal heart rhythm.( when needed)

References

• Chaturvedi V, Saxena A (2009). Heart Failure in Children: Clinical Aspect and Management .Indian J Pediatr, 76(2), 195-205.
• Chen H.H, Schrier R.W. (2006). Pathophysiology of Volume Overload in Acute Heart Failure Syndromes The American Journal of Medicine,119 (12A), 11-16.
• Hsu D.T, Pearson G.D. (2009). Heart Failure in Children Part I: History, Etiology, and Pathophysiology. Circ Heart Fail 2009, 2, 63-70.
• Hsu D.T, Pearson G.D. (2009). Heart Failure in Children Part II: Diagnosis, Treatment,and Future Directions . Circ Heart Fail, 2, 490-498.