Heart Attack (Myocardial Infarction) Causes, Symptoms and When to Worry

Most people who have a heart attack feel pain or discomfort in the centre 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.

A condition that precedes MI is coronary artery disease or myocardial ischaemia (infarction is a clot, ischaemia is damaged or dead tissue – myocardium refers to heart muscle). Arteries can get furred up, causing on/off blockages, which can give symptoms of angina. You may experience brief central chest pain, especially if exerting yourself, such as a brisk walk or lifting something heavy. This will pass by itself, and you can have 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, short of breath or dizzy or light-headed at times, they may even have fainted. These warning signs are a clear indication to get the heart checked, especially if symptoms come on during exercise.

If you suspect you’re having a heart attack or you’re with someone with those symptoms, call 999 for an ambulance. While you wait, you could take 300mg aspirin (4 standard 75mg tablets) to help keep the blood supply flowing to the heart. You will be taken to the nearest Emergency Department with a cardiac unit attached as the clock is running to get you diagnosed and treated within the hour. If you have collapsed and lost consciousness, the ambulance crew and medical team will give you life-saving treatment. 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 ECG to assess the electrics 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.

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).

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 programmes 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.