What is the coronary artery?
The coronary arteries are two small blood vessels that supply blood to the heart wall. The right and left coronary artery have several branches that surround the heart and ensure that the muscular wall of the heart has sufficient oxygen. With the heart working every minute of every day of your life, the blood supply to it has to be extensive and ensure an uninterrupted blood flow. Any problem with the coronary arteries means that the heart does not receive enough oxygen-rich blood to keep pumping efficiently.
What is coronary heart disease?
Coronary heart disease (CHD), also known as coronary artery disease (CAD) and ischemic heart disease (IHD), is where the heart is experiencing difficulty in functioning properly at all times due to an interruption in the blood supply to the heart muscle. Ischemia is a type of injury that occurs when a part of the body does not receive enough oxygen.
In mild coronary artery disease, the blood flow through the arteries may be slightly restricted yet it is not affecting the heart function in any way. However, during times of increased activity when the heart has to pump harder and faster, the blood supply may not be sufficient if the arteries are too narrowed and then it is more correctly known as coronary heart disease or ischemic heart disease.
Causes and Risk Factors
The main cause of coronary artery disease is narrowing of one or more coronary artery by the build up of fatty plaques in the artery wall. This is known as atherosclerosis. It is more likely to occur in a person with high blood pressure (hypertension), with high blood cholesterol levels (hypercholesterolaemia) and who is diabetic.
Who is at risk?
People who are overweight and obese, cigarette smokers, excessive alcohol consumption, a sedentary lifestyle (lack of physical exercise) and a family history of coronary heart disease are the main risk factors. Overall coronary heart disease is one of the main health problems throughout the world and South Africa is no different. It is the main risk factor for having a heart attack (myocardial infarction).
Symptoms of Coronary Heart Disease
Coronary artery disease is often silent in the early stages. You may not experience any signs or symptoms and not know that you have coronary heart disease for years. It is only when the narrowing in the artery reaches a point that it is affecting heart function that a person starts experiencing symptoms. At first the symptoms are only present when the heart has to work harder, like when you are walking faster, running or undergoing psychological stress like getting angry or worried. The symptoms go away shortly after resting.
As the disease worsens, the symptoms may come about suddenly, on its own and even with just moderate physical or emotional strain. These symptoms include :
- Chest pain – crushing, squeezing tight pain around the middle of the chest (angina pectoris)
- Shortness of breath and difficulty breathing
- Pain running up to the neck, along to the arm (particularly the left hand) or down to the abdomen
- Feeling lightheaded or dizzy
- Mild nausea and in rare cases even vomiting
- Paleness of the skin on the face in particular
- Anxiety – a feeling like something bad is happening or you are in danger
- Excessive sweating
Fainting spells can also occur in severe cases especially when you are having a heart attack. It is difficult to assess when these symptoms are due to heart ischemia (injury but not death of the heart muscle) or an actual heart attack (where a portion of the heart muscle dies). Normally the narrowing is not severe enough to totally block blood flow, but there is always a risk of a blood clot forming at this narrowed area and causing a complete obstruction suddenly.
The best way to conclude whether you have coronary heart disease or not is to undergo certain diagnostic tests and scans. An angiogram allows your doctor to see the blood flow through the coronary arteries and identify any kinking in the vessel and restriction of blood flow. There are various other investigations, like blood tests, that can detect certain chemicals in the blood when the heart is undergoing damage. These cardiac enzymes are present and elevated with severe coronary heart disease and with a heart attack. Your blood cholesterol and triglyceride levels are a good indicator if you are at risk of developing coronary heart disease.
Coronary heart disease can be treated in part by medication. Your doctor will prescribe drugs to :
- Control and lower your blood pressure in hypertension.
- Reduce your blood lipids and restore normal cholesterol levels.
- Prevent blood clots from forming in the narrowed coronary arteries.
In the early stages, with a proper diet and exercise, this can to some extent reduce the narrowing. However, in most cases surgery of some sorts is necessary. The two main surgical procedures is coronary artery stenting and heart bypass surgery.
Coronary Artery Stents
The procedure is more correctly known as angioplasty. A thin catheter is inserted into your artery to the point where the narrowing is present. A tiny balloon at the end of the catheter inflates thereby opening up the artery. A stent is then inserted which is essential a mesh ring that will sit in your artery and ensure that it stays open. Coronary artery angioplasty is the preferred procedure even before a heart attack has occurred and can prevent a heart attack.
Heart Bypass Surgery
Coronary artery bypass surgery is a major surgical procedure. It is necessary in a person who has had a heart attack where the artery is severely blocked or it can be performed even before a heart attack has occurred. Basically in this surgery, your doctor will graft a new artery taken from elsewhere in the body to re-route blood around the blocked portion of the coronary artery. This ensures that all the areas supplied after this narrowing have a constant blood supply.