There are four valves which control the blood flow through the heart. They all consist of two or three flaps which swing open to allow blood through with each heart beat, and swing closed to prevent blood going back in the wrong direction.
Deoxygenated (blue) blood returning from the body collects in the right atrium. It flows to the right ventricle through the 'tricuspid valve'. It is then pumped through the 'pulmonary valve' into the pulmonary artery on its way to the lungs. Oxygenated (red) blood returning from the lungs collects in the left atrium and flows through the 'mitral valve' into the left ventricle. It is then pumped through the 'aortic valve' into the aorta and to the body. (Illustration)
The phrase 'congenital heart disease' refers to the various abnormalities of the heart which are present at birth. Other words, such as disorder, defect, condition, or problem, may be used instead of disease.
There are three main types of abnormalities :
There may be a narrowing (called 'stenosis') in parts of the heart, in its valves, or in the blood vessels outside the heart. This narrowing obstructs the flow of blood and puts strain on the heart muscle. In severe cases, the flow of blood past the obstruction may be reduced.
There may be holes in the partitions (septums) between the chambers of the heart. These allow blood to flow from one side of the heart to the other (called 'shunting'). As the blood pressure is higher in the left side, blood flows (shunts) from left to right and results in increased flow to the lungs. The normal communications present at birth may persist between the main blood vessels attached to the heart, e.g. Patent Ductus Arteriosus. This also results in increased blood flow to the lungs.
Abnormalities of the heart are present in nearly 10 in every 1,000 babies born. Some of these are mild and cause no significant disturbance to heart function. In many cases, such minor problems need no treatment and do not affect the life or the health of the child. More serious abnormalities are present in about five of these ten individuals with congenital heart problems.
The total frequency of all birth defects affecting different parts of the body is quite high. Some abnormality occurs in about 25 in every 1,000 babies born. This, however, includes many minor abnormalities.
While most children with a heart problem are born with it (congenital), there are some problems which may develop later (acquired).
Acquired heart problems include 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), and Kawasaki disease (an illness that occurs in young children that may leave the heart muscle or coronary arteries damaged).
If an operation is thought to be necessary, one of the Cardiac Surgeons will discuss the proposed surgery with the child's parents. Sometimes, an operation will be needed urgently in the first few weeks after birth. When there is no major urgency, the operation will usually be performed at the earliest stage with the lowest possible risk, and well before there is likely to be any irreversible damage to the heart, lungs or other organs as a result of the heart problem. This is likely to be within the first one to two years of life in most cases, unless the problem is detected later or does not merit an operation until an older age. Until this time is reached, periodic reviews will be carried out so that any change may be detected and plans altered if necessary.
Children undergoing heart operations usually stay in hospital for about one week, though young infants and some older children may need to stay longer. School age children may then require a few weeks further convalescence at home.
A number of the conditions which require an operation can be dealt with by fairly simple methods. Others can only be dealt with using the heart-lung bypass machine (so called 'open heart' operations). This machine will take over the work of the patient's heart and lungs while the surgeon operates inside the heart itself. Operations with the heart-lung machine involve different (though not necessarily higher) risks than those for which the machine is not needed. Particular problems relating to individual cases will be discussed with parents when surgery is being considered for their child.
Complications from surgery may arise, but with improvements in technology, in surgical procedures and with more surgery being performed at a younger age, the risk of complications is continually being reduced.
The possible complications are related to the specific type of surgery being performed and they vary widely depending on the nature of the problem which requires surgery.
Your child's cardiologist and cardiac surgeon will discuss this subject with you prior to surgery.
There are many risk factors that contribute to the development of cardiovascular disease. Some people are born with conditions that predispose them to heart disease and stroke, but most people who develop cardiovascular disease do so because of a combination of factors such as poor diet, lack of physical activity and smoking, to name just three. The more risk factors you expose yourself to, the higher the chance of developing cardiovascular disease.
Many of the risk factors for cardiovascular disease cause problems because they lead to atherosclerosis.
Atherosclerosis is the narrowing and thickening of arteries. Atherosclerosis develops for years without causing symptoms. It can happen in any part of the body. Around the heart, it is known as coronary artery disease, in the legs it is known as peripheral arterial disease.
The narrowing and thickening of the arteries is due to the deposition of fatty material, cholesterol and other substances on the walls of blood vessels. The deposits are known as plaques. The rupture of a plaque can lead to stroke or a heart attack.
Smoking damages the lining of blood vessels, increases fatty deposits in the arteries, increases blood clotting, adversely affects blood lipid levels, and promotes coronary artery spasm. Nicotine accelerates the heart rate and raises blood pressure.
Estrogen does help raise good HDL cholesterol so protecting women, but once through the menopause as many women as men are affected by heart disease: but if a woman suffers from diabetes or has raised levels of triglycerides that cancels out the positive effect of estrogen.
The symptoms of heart attack in a man are intense chest pain, pain in the left arm or jaw and difficulty breathing.
A woman may have some of the same symptoms, but her pain may be more diffuse, spreading to the shoulders, neck, arms, abdomen and even her back. A woman may experience pain more like indigestion. The pain may not be consistent. There may not be pain but unexplained anxiety, nausea, dizziness, palpitations and cold sweat. A woman’s heart attack may have been preceded by unexplained fatigue.
Women also tend to have more severe first heart attacks that more frequently lead to death, compared to men.