A blocked artery in your heart could put you at risk of a heart attack, so it is one of the issues that your cardiologist will look out for during heart screening. You might also have tests to check your heart for blockages if you’ve been having symptoms that could be caused by coronary artery disease.

What is Coronary Artery Disease?

Coronary artery disease or coronary heart disease is the most common type of cardiovascular disease. It happens when the coronary arteries that supply blood to the heart muscle become blocked or narrowed.

The most common cause of these blockages is a build-up of fatty material or plaque inside the arteries. If too much plaque is deposited in the arteries, it can prevent the blood from flowing properly or even block the blood vessel completely. There is also a risk that clumps or material or blood clots can form, which could move into narrower blood vessels and cause blockages there.

Coronary artery disease usually develops slowly, without causing any noticeable symptoms. However, if the artery becomes very narrow or blocked it can suddenly cause serious problems. The heart cells are very active as the heart is constantly beating, so they need a lot of nutrients and oxygen. If the blood supply through the coronary arteries is restricted, the heart cells might not get the supplies that they need to keep working. The cells won’t be able to move properly, and they may even start to die.

When the heart muscle is starved of oxygen, it can cause angina (chest pain) or a heart attack. The effects can be very serious and may even be fatal, so it is important to know if there are any blockages in your coronary arteries. It may be possible to improve the blood supply to your heart muscle in order to prevent these problems.

Symptoms of Coronary Artery Disease

Coronary artery disease doesn’t usually cause any symptoms until the arteries have become so narrow that the blood supply to the heart muscle is affected. When this happens, you could experience the following effects.

• Angina: a sensation of pain or tightness across your chest, usually focused in the middle or left side. It usually goes away if you rest for a few minutes, but can return when you are physically active, excited, or stressed.
• Breathlessness: you may get breathless more easily when exercising or find that you’re short of breath even when you aren’t doing much. This can be a sign that your heart isn’t pumping enough oxygen around your body.
• Heart attack: if a coronary artery becomes completely blocked, you can have a heart attack. It may cause pain in your arm, jaw or shoulder, crushing pain in your chest, breathlessness, sweating or other symptoms. Sometimes the symptoms can be very mild, in other cases they can be severe or even fatal.

Even if you haven’t noticed any of these symptoms, your cardiologist might still want to check for coronary heart disease, especially if you are at higher risk. You are more likely to be affected if you are over 40, overweight, you smoke, or if you have a problem such as high cholesterol or high blood pressure.

Tests for Blocked Arteries in Your Heart

If you’re experiencing symptoms that could be linked to coronary artery disease or your doctor thinks that you might be at risk, then you may need to have some or all of the following tests.

• Electrocardiogram: a test to measure the electrical activity in your heart that controls the heartbeat. Unusual patterns of electrical activity can indicate that you’ve had a heart attack. You may also be asked to wear a portable ECG monitor for 24-48 hours. It can detect any abnormalities in your heart function that could be linked to interruptions in the blood supply.
• Echocardiogram: an ultrasound scan of your heart can help us to see how well it is functioning. We’ll be able to see how the heart muscle and valves are moving and to assess how well your heart is able to pump blood. It can help us to diagnose coronary heart disease and rule out other possible causes of your symptoms. If any areas seem weaker than usual, it can be a sign that their blood supply is blocked.
• Exercise ECG or echocardiogram: the ECG or echocardiogram can be performed while you are exercising on a treadmill. When your heart is working harder, we may be able to detect problems that weren’t visible while you were resting.
• Nuclear stress test: a radioactive dye or tracer can be injected into your bloodstream and then watched with a special camera while you are on the treadmill. The dye will slow down or move differently as it passes through narrowed or blocked arteries.
• Cardiac angiogram: a special dye is injected into your coronary arteries through a thin tube called a catheter. The dye will show up on X-rays, so we can watch as it moves through the arteries or if it is slowed down by any blockages.
• CT Scan: a scan of your heart can reveal if there are any calcium deposits in the arteries, which could cause the same kinds of problems as fatty deposits.
• CT Coronary Angiogram: if a special dye is injected during the CT scan, it is possible to see it moving along the coronary arteries to find out if there are any blockages or narrowed blood vessels.

The results of these tests can tell your doctor if there are any blockages in your heart. Some of the tests can also show us where the blockage is located, which can be important if you need to have surgery to strengthen or widen the blood vessel.  If a problem is detected, then you may need to make some lifestyle changes to prevent the blockage from getting worse. You might also need treatment to reduce the risks or to improve the blood flow through the affected section of the artery.