8. What can you expect when you visit the paediatric cardiologist?

What can you expect when you go to see the paediatric cardiologist?

          Being told that you or your child might have a birth defect of the heart can be a very stressful situation. Remember that often the suspicion of a heart defect might turn out to be wrong and there might be nothing wrong with your or your child’s heart. Even if there is a problem with the heart it is minor in the majority of patients and may require no treatment or only oral medication.

          During your visit to the paediatric cardiologist your child will be weighed and height ed  Observations including heart rate, breathing rate, blood oxygen level (oxygen saturation) will be carried out by the clinic nurse. The doctor will examine the child’s heart and then decide if further tests are needed.

          

          The tests that are commonly carried out include echocardiography (ultrasound scan of the heart), ECG or electrocardiography (electrical tracing of the heart’s activity), Chest X-ray. Occasionally the cardiologist may decide that cardiac catheterization (explained in previous post) is required to further define the problem.

          

          An echo-cardiogram is an ultrasound scan of the heart (similar to the scan you may have had during pregnancy). This scan helps to look at the heart structure and identify heart defects. It is painless and totally non-invasive. Most children enjoy watching the picture of the heart on the monitor and I liken it to watching TV! I also use this opportunity to explain to the patient or family the various parts of the heart and to point out the abnormalities. An ECG involves placing some electrodes on the chest which help to trace the heart's activity on paper. This is particularly useful when there is suspicion of a problem with heart rhythm.

          

          Once tests have been performed the doctor will be able to explain the problem if there is one or reassure you that all is well. Sometimes further tests may be required. You may or may not need medications or other forms of treatment

7. Treatment of heart defects

Can heart defects be treated?

Many heart defects are minor and require no treatment at all. They may only need regular monitoring. Some heart defects require only oral medications. Some holes in the heart (atrial septal defect, ventricular septal defect, patent ductus arteriosus) and blocked valves (pulmonary or aortic stenosis) can be treated without an open heart procedure using key-hole techniques. More complex heart problems may require surgery.

What are key-hole procedures?

Key-hole procedures involve a technique called cardiac catheterization where a small tube is inserted into the blood vessel at the top of the leg. This is then used to direct catheters (tubes) into the various chambers of the heart. Sometimes these procedures are used to diagnose a problem (diagnostic catheterization) and at other times to treat the problem (interventional catheterization).

Some of the conditions that can be treated using this technique are atrial septal defect (hole between the top two chambers of the heart), ventricular septal defect (hole between the two bottom chambers of the heart), patent ductus arteriosus (extra connection between the lung artery and body artery) and coarctation of the aorta (narrowing of the body artery).

Holes in the heart can be closed without surgery using an umbrella device. This device is placed across the hole and the two discs of the device open on either side of the hole sealing it completely. The device gradually becomes part of the heart and the heart forms a lining or skin over the device. Device closure is a permanent treatment and the hole remains sealed even when the child’s heart grows.

Valves in the heart can become narrowed and these can be relieved using balloons which can be placed across the valve and expanded causing the valve to split open. This procedure which is called ‘Balloon Valvoplasty’ is carried out without surgery using a key-hole approach from the top of the leg.

Sometimes major blood vessels or arteries can be blocked and this can be treated by a procedure called ‘stenting’ where a metal cage is inserted across the narrowed part of the artery and helps to keep it open.

6. How are heart defects detected in children?

How can heart defects be detected in children?

          Heart defects can present at various ages in children. The age of presentation depends on the type and severity of defect.

Some complex, severe defects are obvious right from birth or within a few days of birth. Usually these conditions present with bluish discoloration of the skin (cyanosis) or pallor and poor circulation. If you find these features in a newborn baby make sure you take them to hospital IMMEDIATELY.

Less severe conditions may be detected later in life either due to breathlessness and feeding difficulties or as an incidental finding of a murmur (unusual noise from the heart) which is picked up by the family doctor. Heart defects cause feeding problems in small babies and the typical pattern is that they cannot feed very long so they take small feeds frequently and are constantly hungry. They can also become very sweaty during feeds or when crying. Babies with heart problems are also more prone to getting chest infections or pneumonia which may sometimes need admission to hospital.

Older children can present with chest discomfort/pain and palpitations (awareness of abnormal heart beating). Chest pain in children is usually not related to the heart but a careful examination and assessment should be performed before reassuring the family. Palpitations may be the sign of electrical disturbances in the heart and these can be easily treated nowadays. So thorough investigation is required.

5. Heart and circulation in the unborn baby

       The main difference in the circulation of an unborn baby is the fact that the lungs have no function within the mother's womb. The baby is floating in fluid and the lungs are therefore in a collapsed state. The baby gets oxygen rich blood from the mother's circulation through the placenta. This blood passes from the right upper chamber into the left side of the heart through a hole in the atrial septum (wall between the two top chambers of the heart) which is called the patent foramen ovale (PFO). This hole usually seals off after birth but in 30% of people can still remain open in adult life. This is a normal finding and should not cause any alarm.
       The oxygen rich blood that has reached the left side of the heart is then circulated through the body via the aorta to supply the brain and other organs of the baby. The right side of the heart contains oxygen poor blood and this is pumped into the pulmonary artery (artery to the lung). As the lungs are collapsed this blood does not really have an easy way forward and is diverted through the ductus arteriosus or 'duct' into the aorta which supplies the lower half of the body.

       This form of circulation ensures that important organs like the brain get oxygen rich blood whilst the peripheral organs make do with oxygen poor blood. The duct usually closes within a few days after birth. In some babies particularly premature babies the duct can remain open leading to Persistent Ductus Arteriosus or PDA which may need closure in later life.  

4. The Normal Heart

Hello after a small gap! 

         My next series of blogs will focus on the normal heart and circulation. We will look at what happens in the circulation of the unborn baby and how this changes after birth.

How does a normal heart work?

          The normal heart has 4 chambers, 2 on the right side and 2 on the left side. The upper chamber on the right side is called the right atrium (RA) and the lower chamber is called the right ventricle (RV). Similarly the upper chamber on the left side is the left atrium (LA) and the lower chamber is the left ventricle (LV). There are valves between the upper (collecting) and lower (pumping) chambers on both sides of the heart. The left sided valve is the ‘mitral valve’ and the right sided valve is the ‘tricuspid valve’.

The right sided chambers contain oxygen poor or blue blood and the left sided chambers contain oxygen rich or red blood. The right and left sides of the heart are separated by a wall. The wall between the upper chambers is the atrial septum and the wall between the lower chambers is called the ventricular septum.

‘Blue’ blood from the right pumping chamber is pumped into the lungs through a vessel (tube) called the pulmonary artery. ‘Red’ blood from the left pumping chamber is pumped into the body through a vessel called the aorta.