Heart disease overview: prevention rather than cure

There are two major types of heart disease: coronary heart disease (CHD) which causes heart attacks and is the leading cause of death in the Western world; and heart failure (HF), when the heart’s pumping action deteriorates and which tends to be a phenomenon of later life.

There are other forms of heart disease, for example when the valves in the heart do not function properly; in the case of inflammation of the heart muscle or the sac (pericardium) surrounding the heart; and diseases of the heart’s electrical system giving rise to a range of abnormal and sometimes dangerous irregular heart rhythm: this review will focus on the two principal types.

The heart is a muscle about the size of your fist. It pumps blood around your body and beats about 70 times a minute. After the blood leaves the right side of the heart, it goes to your lungs, where it picks up oxygen.

The oxygen-rich blood returns to your heart and is then pumped to the organs of your body through a network of arteries. The heart gets its own supply of blood from a network of blood vessels on the surface of your heart, called coronary arteries.

About 5,000 people die from coronary heart disease in Ireland every year.

Some 13 per cent of premature deaths here are from CHD. Heart failure affects about 2 per cent of the population but is more common in older people.

CAUSES, SIGNS, SYMPTOMS AND DIAGNOSIS

Coronary heart disease is the term that describes what happens when your heart’s blood supply is blocked by a build-up of fatty substances in the coronary arteries. Over time, the walls of your arteries can become furred up with fatty deposits. This process is known as atherosclerosis and is caused by smoking, high cholesterol, high blood pressure and diabetes.

The commonest symptom of CHD is chest pain. Angina is the name given to a pain in the chest that arises when the heart is short of oxygen. Typically described as a dull, heavy discomfort, angina pain can sometimes be mistaken for indigestion. Some sufferers describe it as tightness or a pressure that starts in the centre of the chest and radiates up into the throat and jaw, into the back or down the left arm.

Angina characteristically comes on during physical activity and fades away when the exertion ceases. It can also be brought on by emotional situations, cold weather or even after a very heavy meal.

As well as chest pain, someone having a heart attack may experience shortness of breath, sweating, nausea, light-headedness or extreme tiredness. A heart attack happens when a complete blockage of your coronary arteries occurs; it may result in damage to the heart muscle.

Diagnosis of all stages of CHD involves an electrocardiogram (ECG), some specific blood tests and the injection of dye into the coronary arteries – a test called coronary angiography.

Heart failure is caused by the heart’s failure to pump enough blood around the body at the right pressure.

Having heart failure does not mean your heart is about to stop working. It simply means your heart needs some support, usually in the form of medicines. There are a variety of causes of heart failure, including stiffness in the muscle wall of the heart, a weakness in part of the heart wall or as a result of diseased heart valves. High blood pressure and coronary heart disease may, over time, cause your heart to fail.

Breathlessness, feeling very tired and ankle-swelling are the main symptoms of heart failure. These can develop quickly in the case of acute heart failure or gradually when it is referred to as chronic heart failure.

Diagnosis of HF is made by physical examination, ECG, chest x-ray and an ultrasound test of the heart called an echocardiogram.

PREVENTION AND TREATMENT

There are numerous possibilities when it comes to treating coronary heart disease. Medication such as nitroglycerine in tablet or spray form can help partially reopen a blocked coronary vessel. Tablets to reduce the amount of cholesterol in your blood and to lower any blood pressure problems may be prescribed. Blood-thinning drugs such as aspirin are used to prevent clots flicking off the blockage and causing further damage.

Many people diagnosed with extensive or severe coronary artery blockages are now treated by inserting a stent into the affected vessel. Firstly a balloon-like device is used to unblock the narrowed artery. Then a wire scaffolding (stent) is placed at the blockage site to keep it open. Some stents are coated with drugs to prevent clot formation.

If you have multiple blockages in more than one artery then coronary bypass surgery may be recommended as the treatment of choice.

Coronary heart disease is easily prevented by making some lifestyle changes. These include: Eating a healthy, balanced diet Being physically active Giving up smoking Controlling blood cholesterol and sugar levels Reducing stress

In most cases, heart failure cannot be cured. But your heart’s function can be improved and medications are available to deal with the excess water that accumulates in the body as a result. Other drugs are designed to make the heart pump a little stronger. Sometimes drugs to regulate the heart rhythm will reduce heart failure. Mechanical devices are also available to act as secondary pumps. And for a limited few, a heart transplant may be the ultimate treatment.

If there is a specific structural cause for the heart failure, such as a faulty valve, then a cure may be possible following surgery to replace the valve.

Preventing heart failure involves lifestyle changes. Maintaining a healthy weight and eating sensibly, including avoiding excess salt in your diet, is important. Too much alcohol can contribute to the development of heart failure, while regular exercise helps keep the heart muscle in good shape.

USEFUL RESOURCES

The Irish Heart Foundation provides information and support for those with heart problems and promotes research into heart disease and its treatment. It can be contacted on 01 6685001 or irishheart.ie.

In the west of Ireland, patients can contact Croí, at 091 544310 or croi.ie

Two useful UK based sites are

[ nhs.uk/Conditions/Coronary-heart-disease  ]

[ bhf.org.uk  ]

Dr Muiris Houston is a specialist in general practice and occupational medicine and a medical education consultant