What is coronary artery disease?

doctor examining patient with stethoscope

The heart is supplied with oxygen through the coronary arteries. Coronary artery disease (CAD) occurs when these vessels harden, with layers of fatty deposits laid down inside the walls.

As the inside of the vessels (the lumen) narrows, less blood passes through, preventing the heart from receiving an adequate supply of oxygen. This blockage can cause pain in the chest (also known as “angina”), or a heart attack. Cardiologists are the specialist doctors who diagnose and treat patients with coronary artery disease and related conditions.

What are the symptoms of coronary artery disease?

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Coronary artery disease develops slowly with no symptoms until there is significant progression of the disease. Symptoms of coronary artery disease are

● angina
● shortness of breath
● heart attack

What are the causes of and risk factors for coronary artery disease?

Coronary artery disease starts when the inner layers of coronary arteries are damaged. Fatty deposits comprising cholesterol and other materials called plaque begin to build up in these damaged areas. This gradual accumulation is called atherosclerosis.

If the plaque breaks off, blood cell fragments called platelets begin to form at the site of injury, clumping together to form clots.

As more plaque accumulates, less blood flows through the arteries, and the heart muscle is deprived of oxygen. This can lead to chest pain (angina) or a heart attack. Most heart attacks happen when a blood clot suddenly cuts off the heart’s blood supply, causing permanent heart damage.

Coronary artery disease affects men and women. Several factors can increase your risk of developing coronary artery disease, including:

● Age
● Family history of heart disease
● High blood pressure
● High cholesterol
● Being a current or previous smoker, as smoking reduces the flow of oxygen to the heart and increases blood pressure, heart rate, and blood clotting as well as damaging the cells lining the arteries.
● Poor diet
● Obesity or being significantly overweight
● Inactivity (sedentary lifestyle)
● High blood pressure
● Diabetes
● Difficult pregnancy with preeclampsia, as a woman is most likely to develop heart disease during pregnancy or post-menopause.
● Gum disease as swollen gums is often associated with heart disease

Enquire with our cardiologists.

Did you know?

Coronary artery disease is also known as Ischemic Heart Disease (IHD). Coronary artery disease is a significant health issue for Singapore. According to the Singapore Ministry of Health, in 2010, the disease accounted for 10.4% of the disease burden and 19.9% of the mortality burden for the resident population1.

What are the possible complications of coronary artery disease?

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Over time, coronary artery disease weakens the heart muscle, contributing to heart failure and arrhythmias. Heart failure occurs when the heart cannot circulate blood sufficiently to the rest of the body. Arrhythmias are changes in the normal beating rhythm of the heart.

When should I see a specialist for coronary artery disease?

You should consider seeing a cardiologist if you have symptoms such as:

● Severe pressure, squeezing, pain, or discomfort in the chest
● Pain or discomfort that spreads to the shoulders, neck, arms, or jaw
● Chest pain that becomes more intense
● Chest pain that isn’t relieved by rest
● Rapid or irregular pulse
● Pain in the jaw, neck, upper back, and/or chest
● Hoarseness because of pressure on the vocal cords
● Difficulty swallowing
● Heart palpitations
● Anxiety
● Low blood pressure

How should I prepare for my appointment?

As your cardiologist will ask you for your past medical and family history, be prepared with the following information:

● Current symptoms that you are experiencing, including those that seem unrelated
● Current or previous medical conditions including any treatments such as diabetes or stroke
● Results of previous laboratory tests such cholesterol tests
● List of medications, vitamins or supplements you are currently consuming
● Be prepared to discuss your diet and your smoking and exercise habits. If you don’t already follow a diet or exercise routine, discuss getting started with one.

If possible, bring someone along with you to help remember what your specialist tells you.

To enable you to make better choices as you cope with coronary artery disease, you may wish to ask the specialist the following questions.
● How many arteries are blocked?
● What is the extent of the blockages?
● What are the signs that I need to go to a hospital or seek treatment right away?
● What are the side effects of medication to treat coronary artery disease?
● Are there any alternatives to the treatments suggested?
● I have other health conditions. How do I manage them together?

How do specialists diagnose coronary artery disease?

Your cardiologist will diagnose coronary artery disease based on your medical and family histories, your risk factors, a physical exam, and the results from tests and procedures. The following tests may be done.

● Coronary angiography (also called an angiogram) is a procedure that uses contrast dye and x-rays to look at the lumen of your arteries. It can show if there is plaque accumulation and the degree of narrowing. Cardiologists use this procedure to diagnose heart diseases after chest pain, sudden cardiac arrest, or abnormal results from other heart tests such as an EKG or a stress test.

● A cardiac CT (computed tomography) scan uses a large doughnut-shaped machine that generates x-rays to take images of your heart and its blood vessels. These images are combined to create a three-dimensional (3D) model of the heart to help detect or evaluate calcium buildup in the coronary arteries, problems with the aorta, heart function, and valves and pericardial diseases. Prior to the scan, an injection of contrast dye will be given to help highlight your heart and blood vessels in the images.

● Cardiac MRI (magnetic resonance imaging) uses radio waves and magnets in a large tunnel-like machine to create detailed images of your heart. A cardiac MRI can also help your cardiologist decide the best way to treat heart problems such as CAD, heart valve problems, or pericarditis. As with the CT scan, you might get an injection of contrast dye to highlight your heart and blood vessels in the images.

● Chest x-rays are commonly done to show the organs and structures inside your chest. It can reveal signs of heart failure and lung disorders.

● Echocardiography is an ultrasound of the heart to create dynamic pictures of your heart that shows the shape and size of your heart, as well as how well your heart’s chambers and valves are working.

● Electrocardiogram, also known as ECG or EKG, examines the electrical impulses of your heart beat, showing the speed and rate of the beats. This will help them determine any abnormality and identify the cause. Electrodes are placed on the skin of the chest, arms and legs and connected to machines that record the electrical activity.

● Stress testing is typically done on a treadmill and used by cardiologists to measure heart activity during exercise. It can help diagnose coronary artery disease and check for other problems, including heart valve disease and heart failure. An electrocardiogram would be done along with blood measurement monitoring. If you are unable to exercise, drugs may be given to make your heart work hard and beat fast. A radioactive drug will be administered and special cameras used to take images of your heart.

What treatments are available for coronary artery disease?

The immediate treatment goal for coronary artery disease in the event of angina or a heart attack is to widen or bypass clogged arteries. These procedures are:

● Percutaneous Coronary Intervention, commonly known as angioplasty, which is a nonsurgical procedure that helps to unclog the coronary arteries. A plastic tube with a balloon at the end is guided through a blood vessel to the blocked artery. The balloon is inflated to press the plaque against the wall of the artery, restoring blood flow. Your cardiologist may also insert a mesh tube called a stent, to prevent future blockages in the artery.
● Coronary Artery Bypass Grafting is a surgical procedure where arteries or veins from another part of the body are used to create an alternative passage around your narrowed coronary arteries. This procedure improves circulation around the heart and relieves symptoms.
The longer-term goals for coronary artery disease treatment are
● Reducing the risk of blood clots formation as blood clots can cause a heart attack
● Preventing complications
● Reducing risk factors to slow down, stop, or reverse the plaque accumulation
● Relieving symptoms

To achieve these goals, the cardiologist may

● Suggest changes to your current lifestyle habits to eat healthier and reduce stressors
● Prescribe medicines such as statins to reduce your LDL (“bad”) cholesterol level and ACE (angiotensin-converting enzyme) inhibitors to help lower blood pressure
● Propose cardiac rehabilitation, a medically supervised program comprising education, counselling, and training to inform you of your heart condition and help you cope with the stress of adjusting to a new lifestyle, and also exercise training to help you learn how to exercise safely, strengthen your muscles, and improve your stamina.

At Mount Elizabeth Medical Centre, our highly experienced cardiologists aim to help you live a healthy life. We are here to partner our patients and help them achieve their treatment goals.

Request an appointment with a cardiologist today.

[1] Epidemiology & Disease Control Division, Ministry of Health S. SINGAPORE BURDEN OF DISEASE STUDY 2010. 2014.