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Heart attack

Dr Karen Martin
Reviewed by Dr Karen MartinReviewed on 10.10.2024 | 5 minutes read
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A heart attack, also known as myocardial infarction or coronary thrombosis, happens when a coronary artery (a blood vessel that supplies the heart with blood) that carries oxygen-rich blood to the heart is blocked. If the blood supply is completely blocked, part of the heart muscle may be starved of oxygen, can become damaged and may die. The medical name for a heart attack is an acute myocardial infarction (MI). Although having a heart attack is very serious, the chances of survival are greatly increased if you are able to get to a hospital right away.

A heart attack may also refer to a problem with the rhythm of the heart – an arrhythmia – that prevents it beating in synchrony to pump blood around the body effectively. Again, this can lead to a medical emergency.

What causes an MI?

Certain things can put you at higher risk of an MI. Age is the biggest factor, where our arteries become less elastic as we age, and we get build-up of plaque on the inside of the arteries (a bit like lime scale in a water pipe). Plaque causes less effective flow of blood as the tube is narrower, and a piece of plaque may break off to form a clot, causing a blockage.

Other conditions can accelerate this process, including diabetes, high blood pressure, abdominal aortic aneurysm, high cholesterol, obesity, excess alcohol and smoking. Your family history or ethnicity can cause early-age plaque build-up in the arteries.

What are the symptoms?

Most people who have a heart attack feel pain or discomfort in the center of their chest. This central chest pain is often described as a sensation of heaviness, tightness or squeezing, and may come on suddenly. It can also feel like bad indigestion, but other symptoms may include pain spreading to the jaw, neck, arms, back or stomach, feeling sweaty or breathless, light-headed or dizzy, or feeling sick or vomiting. It is important to remember that the symptoms of a heart attack can vary from person to person.

A severe arrhythmia can cause immediate collapse, and is more likely to cause shortness of breath, feeling faint or dizzy or feeling the heart beat fast or slow just beforehand.

I’m worried now, are there warning signs?

A condition that precedes MI is coronary artery disease or myocardial ischemia (infarction is a clot, ischemia is damaged or dead tissue – myocardium refers to the heart muscle). Arteries can get clogged, causing on/off blockages, which can give symptoms of angina. You may experience brief central chest pain, especially if exerting yourself, such as brisk walking or lifting something heavy. This will pass, and you can be prescribed treatment to help symptoms, but this should be checked out thoroughly to get the diagnosis.

In arrhythmia, people may notice the heart beating very fast or slow at times, or it’s irregular or missing a heartbeat every once in a while. They can feel palpitations, shortness of breath, dizziness, and light-headedness at times, and they may even have fainted. These warning signs are a clear indication to get the heart checked, especially if symptoms occur during exercise.

What happens when I get to the hospital?

If you suspect you have a heart attack or you’re with someone with those symptoms, call 911 for an ambulance. While you wait, you could take 325 mg aspirin (1 regular tablet or 4 baby tablets) to help keep blood flowing. You will be taken to the nearest Emergency Department with a cardiac unit attached. The clock is running to get you diagnosed and treated within the hour. The ambulance crew and medical team will give life-saving treatment if you have collapsed and lost consciousness. If you are conscious, they will assess your vital signs – your blood pressure, heart rate, and breathing rate – and they will listen to your heart and lungs. They will use an electrocardiogram (ECG) to assess the electrical system of your heart, and they will take blood samples. Both the ECG and blood samples can definitively point to a heart attack, and they may use other imaging to check where the blockage is.

How is an MI treated?

This depends on the severity of the heart attack. There are two commonly used ways to restore blood flow in a blocked artery.

Thrombolysis. Here, a combination of medication is given to dissolve the blood clot and restore the flow of blood to the heart.

Angioplasty. This aims to widen your artery by inflating a balloon in your narrowed or blocked coronary artery. A wire mesh tube called a stent is usually inserted to hold the coronary artery open. This can be done as an emergency procedure (also known as a primary angioplasty) or as a planned procedure. Sometimes a coronary angioplasty isn’t possible, for example if the blockages in your arteries are too long for a stent or they’re difficult to get to, and you may be offered a coronary artery bypass graft (CABG) instead. CABG is an operation to bypass a narrowed section of your coronary artery using a blood vessel from your chest, leg or arm. This diverts the flow of blood around the narrowed or blocked coronary artery.

The hospital doctors can then give treatment to open up the damaged artery – either medicine to disperse the clot or by inserting a tube (stent) in the vessel to keep it open, in a procedure called percutaneous coronary intervention (PCI).

What else can I do?

While you can’t change your genetics or age, you can take control of other risk factors. This means that keeping active, eating healthily and maintaining a healthy weight will all help, along with stopping smoking, reducing alcohol, losing excess weight and following advice to control your diabetes or blood pressure. It’s a tough concept to come to terms with, but the reason your doctor (and probably your family members) ask you to look after yourself, is that you’re investing in your future!

Rest is important after a heart attack, but it's just as important for you to participate in recreation and social events and to begin making physical activity a part of your daily life. A good night's rest is especially important for heart attack patients, and if you feel tired during the day, take a nap or a short rest. Most heart attack patients go back to work within two weeks to three months depending on the severity of the heart attack. Your doctor will determine when you can go back and if your current job is suitable for a person who has had a heart attack.

Heart rehabilitation programs are helpful following a heart attack in helping to change unhealthy lifestyle habits. These programs often take place at a hospital with a rehabilitation team or with the help of your doctor, nurse, dietitian or other healthcare professionals.

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Dr Karen Martin
Reviewed by Dr Karen Martin
Reviewed on 10.10.2024
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