Heart Attack (Myocardial Infarction or MI)

Heart Attack (Myocardial Infarction or MI)

What is a heart attack?

How does my heart work?

Your heart is a specialised and vital muscle that pumps blood throughout your body. Your heart has two pumps that work together in order to pump blood. The blood coming from your organs and tissues, enters the right side of your heart, your heart then pumps the blood to your lungs. Your lungs will then remove any waste carbon dioxide from the blood and refuel it with oxygen.

The other side of your heart, the left side, pumps oxygen-rich blood that has returned from your lungs to all the parts of your body, including the heart itself. This process makes sure that there is a constant supply of oxygen and nourishment in order for your body to effectively function.

The following article will take a look into the causes, symptoms and treatment of a heart attack and also covers some further questions you may have about the matter. This article is purely intended as a guideline and not as a professional prognosis or treatment in anyway. Please consult with a doctor or healthcare professional for that.

What happens when someone has a heart attack?

A heart attack, also referred to as myocardial infarction (MI), is when blood is unable to get to your heart. A heart attack is called a myocardial infarction due to ‘myo’ meaning muscle, ‘cardial’ referring to the heart and ‘infarction’ referring to tissue dying due to the lack of blood flowing to it.

When this happens, the heart muscle cannot get the oxygen it needs to function and the cells of the heart may be damaged or die. 

The coronary arteries are responsible for supplying the heart with oxygen rich blood, if you suffer from a heart condition such as coronary artery disease, which is also known as coronary heart disease (CHD), your arteries are narrowed and therefore limit the blood flow. This is a leading cause of heart attacks. This disease refers to the build-up of plaque in your arteries, making your once elastic and smooth arteries, more rigid and causing blood flow to be restricted.

The plaque build-up consists of fatty matter, proteins, calcium, inflammatory cells and cholesterol that accumulate in the arteries. These plaques are made up of different sizes, they are soft on the inside and hard on the outside. If the outer shell of the plaque cracks, known as a plaque rupture, then platelets come to the area to help the blood to clot, forming blood clots around the plaque rupture. When this happens, the blood clot can block up the artery and starve the heart muscle of oxygen, this in turn permanently damages the heart and may lead to death – this is a heart attack.

Another less common cause of a heart attack is the result of a spasm of the coronary artery. When a coronary spasm occurs, the coronary arteries are either restricted or spasm intermittently. This spasm effect reduces the flow of oxygenated blood to the heart, and may occur at rest and is known to occur even in people who do not suffer from coronary artery disease.

The damage done to the heart depends on the size of the area affected by the blocked artery as each coronary artery supplies blood to a specific region of the heart muscle. It is also dependent on the time between the injury and receiving treatment.

Should the patient survive the heart attack, the heart muscle will begin to heal quite soon after, and will take about eight weeks to recover. The heart will form new scar tissue to the damaged area, however, this new tissue does not have contracting abilities, therefore the heart’s ability to pump is lessened.

What are the symptoms of a heart attack?

A heart attack should be taken seriously, some people may or may not show symptoms of having a heart attack. Should you feel as though you or someone else is having a heart attack, immediately call an ambulance in order to get the right medical help needed as this can be the difference between life and death.

The symptoms of a heart attack last longer than 30 minutes and some people who are having a heart attack may not display any symptoms at all, this is known as a silent myocardial infarction, it can occur in anyone but it more common in those with diabetes.

That being said, the following is a list of symptoms of a heart attack:

  • Chest pain that feels like your chest is being squeezed or pressed by a heavy object, this pain can radiate from the neck, arms, back and jaw. Men specifically may feel a pain down their left arm.
  • Feeling full and possibly experiencing indigestion that may feel like heartburn or even be choking.
  • Starting to sweat and feeling dizzy, vomiting and nauseous.
  • Having rapid or irregular heartbeats.
  • Feeling extremely weak, emotions of anxiety can arise as well as a shortness of breath.

What to do when someone is having a heart attack

Woman calling for help

When someone is exhibiting the above symptoms, they may be having a heart attack. It is important to immediately seek medical assistance.

The person having the heart attack needs to be treated within two hours in order to increase their chances of recovery.

When you phone the ambulance, get the person to take an aspirin (unless they are allergic) as this may lower their risks of a blood clot. If they become unconscious, hands-only CPR (Cardiopulmonary resuscitation) can almost double their chances of survival.

Quick treatment must be administered and can sometimes begin in the ambulance (once a heart attack is the confirmed diagnosis), the medical professionals will normally use medication to dissolve blood clots or perform surgery to help restore blood to the heart and possibly unclog the blocked artery.

How is a heart attack detected?

In order to properly diagnose the heart attack, the emergency care team, normally the ambulance team to first get to you or the person having a heart attack, will evaluate and check the symptoms. If you are with someone who is having a heart attack, you may also be asked about the sufferer’s symptoms should they be unconscious.

The primary goal is to administer the necessary treatment as quickly as possible in order to limit the amount of damage to the heart muscle. The diagnosis is determined on the symptoms and applicable test results.

What tests are conducted to diagnose the heart attack?

There are a number of tests that are conducted to diagnose a heart attack, these are:

  • An electrocardiogram (ECG), this is used to determine how much damage has occurred to the heart muscle and where the damage has occurred, it also evaluates your heart rate and rhythm. It shows the heart’s electrical activity on paper with line tracings. These are waves drawn on the paper called spikes and dips.
  • Blood tests to measure the cardiac enzymes levels that indicate the extent of damage to the heart muscle. These enzymes are usually found on the inside of the cells of your heart and are needed for the function of the cells. When the heart muscle cells become damaged, the cell content and enzymes are released into the bloodstream, the amount released helps your doctor to determine the size and start of the heart attack.

    Troponin
     proteins are also found in the cells of the heart and are released when they are damaged due to a heart attack, when these proteins are detected in the blood it may indicate a heart attack.
  • An echocardiography can also be conducted. It is a sound test to show how the heart is pumping and what areas are functioning normally. This test can be used during or after a heart attack. The test gives off echoes to reflect the pumping of the heart and can also determine if any structures of the heart have been damaged during the heart attack.
  • A cardiac cath (cardiac catheterization) may also be used in the first few hours of the heart attack if the medication is not able to relieve the symptoms. It can be used to determine where the blocked artery is and what procedure to undergo to directly fix the blockage.

    How this works is a probe is inserted into your blood vessels through the use of a flexible tube known as a catheter. This gives your doctor a direct visualisation of the affected area and where the plaque may have built up. A dye can also be injected through the catheter and into your arteries to see how the blood flows and examined through the use of an X-ray to determine if there are any blockages.

What is the treatment for a heart attack?

A doctor who treats issues of the heart is known as a cardiologist. The cardiologist, through some of the above tests, will determine if surgical or nonsurgical treatment is the best solution for each case. The chosen procedure will often help to prevent a heart attack from reoccurring and can help to relieve the pain of the current heart attack.  

The following is a list of treatments your doctor may perform:

  • Coronary angioplasty and stenting is a well-known procedure, however, it requires specific equipment and qualified personnel. For this procedure, you will most likely be taken to a specialist hospital. During the procedure, a small balloon catheter with an elongated balloon on the end is inserted into a large artery in your arm or groyne. The catheter then passes through your blood vessels and moves up to your heart, using X-rays to guide it, it then moves into the narrowed coronary artery section.

    When it has reached its intended position, the balloon at the end of the catheter is inflated to open up the narrowed section of the artery. A flexible metal mesh, known as a stent, is then normally placed into the artery to keep it open and the balloon catheter is removed.
  • Coronary artery bypass surgery is sometimes performed in some emergency cases at the time of the heart attack. Or, your doctor may recommend the surgery take place a few days after the heart attack. This surgery involves attaching healthy arteries or veins to a narrowed or blocked coronary artery to allow blood to flow to the heart through the attached artery and bypass the narrowed section. This is also known as open heart surgery. Today however, the procedure only involves small incisions and not necessarily wide openings – therefore the name can be misleading.

Stenting

What medication is used for the treatment of a heart attack?

The cardiologist may prescribe one or a combination of the following medications:

  • Antiplatelets such as aspirin to stop the blood from clotting.
  • Clot busters (thrombolytic therapy) to dissolve the blood clots in the arteries of the heart.
  • Blood thinners known as anticoagulants.
  • Blood pressure medication may also be prescribed to regulate the blood pressure.

What are the complications of a heart attack?

Complications can be related to the heart damage that has occurred. These complications can lead to some of the following complications:

  • Arrhythmias, known as abnormal heart rhythms, which are basically electrical short circuits which can stop the heart beating altogether, which often results in a fatal heart attack.
  • A heart rupture is due to the damaged heart muscle area, leaving a hole in the heart that is often fatal.
  • Heart failure can occur after the heart tissue has suffered from extensive damage affecting the heart’s ability to pump properly. Heart failure can be a temporary condition or develop into a chronic condition, depending on the damage done.
  • Heart valves that have been damaged may cause severe leakage issues.

What are the risk factors for a heart attack?

There are certain risk factors that can add to the unhealthy build-up of fatty deposits causing your arteries to narrow, there are also precautions and lifestyle changes that can be taken, however, it is important to note what the risk factors are in order to address them accordingly. These are listed below:

  • Men over the age of 45 and women over the age of 55 are more likely to have a heart attack.
  • Smoking tobacco products and even second-hand smoke over a long period of time can increase the risk of heart attack.
  • High blood pressure is known to damage the arteries over time, it can occur with obesity, diabetes, smoking and high cholesterol.
  • High levels of the bad type of cholesterol, being low-density lipoprotein (LDL), is known to narrow your arteries, increasing heart attack risks.
  • Being diabetic - not producing enough insulin or being less respondent to it, can cause the blood sugar levels of the body to rise, this leads to damage of the nerves and blood vessels.
  • Genetics play a role. If you have a direct family member who has suffered from an early heart attack, you may be at risk.
  • Obesity, which may lead to high blood cholesterol levels, diabetes and high blood pressure increases your overall risk.
  • Illegal drug usage such as amphetamines or cocaine is known to trigger spasms of your coronary arteries which causes a heart attack.
  • Having an autoimmune disease, such as rheumatoid arthritis or lupus increases your risk.

How do you lower the risk of having a heart attack?

Taking medications that have been prescribed after a heart attack can help a heart that has been damaged to function better. Speak to your doctor about monitoring your progress to ensure a swift and healthy recovery.

Making changes to your lifestyle are a great step to take in preventing the occurrence or reoccurrence of a heart attack. Here are ways you can change your lifestyle:

  • Stop smoking and avoid being around people who smoke.
  • Keep your blood pressure and cholesterol levels under control – speak to your doctor about possible medications and medical monitoring for this.
  • Go for regular check-ups at a medical professional in order to pick up any conditions such as arthritis and diabetes.
  • Take up or maintain a routine of regular physical activity. Just walking for 30 minutes a day, five days of the week, can help to improve your health.
  • Speak to your doctor or a dietician about sticking to a heart-healthy diet. This includes staying away from saturated fats, trans fats and cholesterol and sticking to lean proteins and lots of whole grains, fruits and vegetables.
  • Try to control your stress levels, speak to your doctor or psychologist about managing your stress.

Some more answers about heart attacks

What is the main cause of a heart attack?

Coronary heart disease that stops the blood flow to the heart. This the build-up of plaque in the arteries which is formed over time by proteins, fatty acids (cholesterol) and inflammatory cells. The plaque causes a rupture which sends blood clotting cells (platelets) to the site of rupture, clotting the blood and not allowing it to get to the heart.

What is coronary heart disease?

Coronary heart disease is the build-up of plaque inside your coronary arteries which are responsible for transporting oxygenated blood to your heart. From our youth, plaque can start to go into your blood vessel walls, and as we get older the plaque builds up. This causes your artery walls to inflame and the risk of blood clots and heart attacks to rise.

In simple terms, this plaque causes the inside of your blood vessels to become sticky, then, things like lipoproteins, calcium and inflammatory cells as well as cholesterol start to accumulate, increasing the plaque and causing the vessels to narrow.

In most cases, the affected artery may create new blood vessel to get past the blockage and get blood to the heart. But, if you are experiencing high levels of stress, the new arteries may not be able to effectively transport blood to the heart.

In other cases, the ruptured plaque creates a blood clot, causing a heart attack.

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