The normal heart is composed of four chambers. The two upper chambers (atrium) are reservoirs which collect blood as it flows back to the heart. From the atriums, blood flows into the lower two chambers (ventricles) which pump blood, with each heart beat, into the main arteries. From the right side of the heart one of these arteries (the pulmonary artery) carries blood to the lungs for re-oxygenation. The left side of the heart pumps blood into the other main artery (the aorta), which takes blood to the rest of the body.
The two ventricles and the two atriums are separated by partitions called ‘septums’. The partition between the atriums is called the ‘atrial septum’ and the one separating the two ventricles is the ‘ventricular septum’. Deoxygenated blood returns to the right atrium from the body through the two main veins called the ‘superior vena cava’ and ‘inferior vena cava’. It is pumped by the right ventricle to the lungs for replenishment with oxygen. This oxygenated blood returns through two veins from each lung, to the left atrium and is pumped by the left ventricle to the body again.
The heart has its own internal pacemaker which controls its normal rhythmical beating. It creates an electrical impulse which causes firstly the atriums, and secondly the ventricles, to contract in turn. With each contraction the blood is pumped, then the heart muscle relaxes and the chambers refill with blood, ready for the next contraction.
Holes (or communications) between the atriums (foramen ovale) and between the two main arteries (ductus arteriosus) do exist up until birth. These usually close in the early days or weeks after birth. These communications allow blood to bypass the lung circulation before birth, as the lungs are not yet functioning.
Congenital heart disease is often viewed as a group of gross structural or functional abnormalities of the heart that are present at birth.
Abnormalities of the heart are present in nearly 8-10 in 1000 live birth in world wide.
In most cases the cause of the heart abnormality is unknown.
Some causes are as below :
- Maternal infection during pregnancy
- e.g viral infection (Rubella infection)
- Medications (e.g. anticonvulsant , ACEI,), alcohol, cigarette smocking.
- Maternal diabetes and hypertension
- Maternal connective tissue disease ( SLE)
- CHD 1 % in general population, 15% if mother has CHD
- Low birth weight/IUGR indicate intrauterine infection (Rubella syndrome).
- Hereditary cause (e.g Marfan’s syndrome, Noonan’s syndrome,Holt-Oram syndrome, Long QT syndrome)
- Genetic disorders (Down syndrome and DiGeorge syndrome).
When one child has a congenital heart problem, the risk for the next pregnancy is usually between 2% and 4%.
Yes. There are some problems which may develop after birth (acquired).
- Myocarditis (where the heart muscle becomes inflamed and may be damaged by a viral infection).
- Cardiomyopathy (a disease of the heart muscle which can be caused by a genetic disorder or can develop following an infection).
- Rheumatic heart disease (resulting from rheumatic fever which may lead to damage to the heart muscle and in particular to the heart valves).
- Kawasaki disease (an illness that occurs in young children that may leave the heart muscle or coronary arteries damaged).
- Typical feeding pattern (suck and sleep cycle : small feed followed by sleeping) >Poor feeding.
- Poor sleep, irritability.
- Excessive sweating and respiratory distress/chest in drawing during feeding and playing/at rest.
- Frequent lower respiratory tract infection(e.g pneumonia) for which baby takes antibiotics and may need frequent hospital admission.
- Poor weight gain and development.
- Cyanosis, cyanotic spells and squatting.
- Exsercise intolerance
- Chest pain
- Joint symptom
Most of the heart diseases are curable if babies with heart diseases come to a Paediatric Cardiologist timely.
- We can prevent congenital and acquired diseases to some extent. Because only some causes are known. And most of the causes are still unknown.
- Three months before pregnancy MMR vaccine can prevent congenital Rubella syndrome which is associated with heart diseases.
- Rheumatic heart disease can be prevented by proper treatment of rheumatic fever.
- Prevention of elderly marriage can prevent some syndrome (Down syndrome) which have association with congenital heart diseases.
- Prevention of some risk factors as maternal diabetes, hypertension should be controlled during pregnancy.
- Avoidance of taking teratogenic drugs can prevent congenital heart diseases.