Infarction (Heart Attack): see causes, symptoms, treatment


What is Heart Attack (Infarction)?

Heart attack (infarction) is the failure of oxygenated blood in the area of ​​the heart due to the obstruction of a coronary artery. Because the blood is unable to flow in the region, the muscle enters a process of necrosis, which can lead the patient to death.

The obstruction of the coronary artery in question usually happens due to a blood clot that forms above the fat plaque that lines the vein, which leads to the impossibility of the blood to flow (ischemia) and cause, consecutively, cell death.

According to the Ministry of Health, about 300 thousand infarctions happen every year in Brazil and, of these, 80 thousand end up being fatal or for not receiving the appropriate treatment or for not controlling the risk factors that can trigger the disease. Due to technological developments over the years, the mortality rate currently makes up about 4 to 5% of all cases, that is, 10 times less than 50 years ago.

In addition to this name, the heart attack may be known by other names, such as:

  • Myocardial infarction;
  • Acute myocardial infarction;
  • Acute coronary syndrome;
  • Coronary thrombosis;
  • Coronary occlusion.

Is heart attack the same as cardiac arrest?

No. As explained, infarction is the low blood flow in the heart muscle due to an obstruction in one of the heart’s veins. Cardiac arrest happens when the heart stops beating, as well as distributing blood to the rest of the body. As much as a heart attack can cause cardiac arrest, the two conditions are not the same.

Index – in this article you will find the following information:

  1. What is Heart Attack (Infarction)
  2. Classification and Types of Infarction
  3. Causes of Infarction
  4. Risk factors
  5. Infarction Symptoms
  6. Diagnosis and First Aid
  7. Treatment
  8. Recovery
  9. Complications
  10. Prevention

Classification and Types of Infarction

Infarction is classified, usually into two types:

  1. STEMI infarction: means that the patient suffered a ST segment elevation myocardial infarction, that is, when there is a complete coronary artery block;
  2. NSTEMI infarction: this type occurs when myocardial infarction does not have an elevation of the ST segment, that is, the coronary artery block occurs in a partial way.

In addition to these, a consensus document (2007) classified the condition into five other main types:

Type 1

Spontaneous infarction related to ischemia due to a primary problem in the coronary artery, such as erosion and / or rupture of the plaque, fissure or dissection.

Type 2

Infarction secondary to ischemia due to increased demand for oxygen or decreased supply, which occurs in situations such as:

  • Coronary artery spasm;
  • Coronary embolism;
  • Anemia;
  • Arrhythmias;
  • Hypertension;
  • Hypotension.

Type 3

Cardiac muscle death unexpectedly, including cardiac arrest. In this type, the frequent symptoms are suggestive of myocardial ischemia, accompanied by a new ST elevation, new blockade of the left branch or evidence of fresh thrombus in the coronary artery.

Type 4

It is associated with coronary angioplasty or stenting (a tube inserted in some conduit of the body to prevent or prevent blood flow from being impeded) and has two subtypes:

  1. Type 4a: infarction associated with percutaneous coronary intervention;
  2. Type 4b: infarction associated with stent thrombosis.

Type 5

Infarction associated with myocardial revascularization surgery.

Causes of Infarction

A heart attack occurs when one or more of your arteries is blocked. Because of an accumulation of various substances, including cholesterol, the artery can narrow, creating a disease called Coronary Artery Disease , the main cause of most of the strokes already diagnosed. During an episode of infarction, one of these plaques of substances can rupture and spill into the bloodstream, forming a blood clot at the site of the rupture, preventing the blood flow from reaching the heart muscle in sufficient quantity.

Another very common cause of infarction is a spasm of a coronary artery, which completely shuts off blood flow to the heart. The use of tobacco and illicit drugs can greatly facilitate a case of spasm and can often be fatal. In addition, a heart attack can also occur due to a tear in the artery of the heart.

Risk factors

There are several factors that can trigger a heart attack. Among all, you can divide them into 3 groups:

  1. Main risk factors: research shows that certain immutable factors considerably increase the chances of developing cardiovascular disease;
  2. Modifiable risk factors: most of the risk factors for infarction can be modified, treated or controlled through lifestyle changes or the use of medications;
  3. Contributing risk factors : these are factors associated with an increased risk of cardiovascular disease and which also influence in cases of infarction.

Main risk factors

These are the risk factors that cannot be modified. Know what they are:


Most people who die from a heart attack are 65 or older. At older ages, women are more likely than men to die within weeks of the episode.


Men have more risks of having a heart attack when compared to women, in addition to being able to experience the condition at an earlier age.


Because of the loss of vascular protection provided by female hormones, women in menopause are at a greater risk of developing a heart attack than those who are not yet in that phase.


Children of cardiac parents are more likely to also develop heart disease. In addition, black people have higher blood pressure than Caucasians, thus increasing the risk of heart disease.

History of pre-eclampsia

This condition causes an increase in blood pressure during pregnancy, increasing the risk of developing heart disease.

History of autoimmune diseases

Diseases like arthritis or lupus can increase a patient’s risk of having a heart attack.

Modifiable risk factors


Even though there are unalterable risk factors, there are those that have the chance to be controlled through the person’s lifestyle, and these are in large quantities. Therefore, by changing the lifestyle you have, your risk of developing a heart attack will most likely be lower.


Smokers are more likely to have a heart attack, because tobacco is a strong risk factor for sudden cardiac deaths. In addition, the substance also increases the risk of developing coronary heart disease. The same goes for passive smokers (ie non-smokers who have direct contact with smokers).

High cholesterol

As a person’s cholesterol level increases, their risk of developing coronary heart disease also increases. When other risk factors are present, such as smoking and hypertension, this risk increases even more.


In a person who has his blood pressure higher than normal, the workload of the heart is increased, which causes the heart muscle to thicken and become more rigid. With this stiffening, the organ does not function properly, and may increase the risk of stroke, heart attack, kidney failure and congestive heart failure.

When high blood pressure is combined with obesity , smoking, high cholesterol or diabetes , the risk of heart attack and stroke is further increased.

Sedentary lifestyle

People who are physically inactive are more likely to have a heart attack. The practice of physical activity helps in the control of high cholesterol, diabetes and obesity, as well as helps to lower the blood pressure of some people.


Anyone who has excess fat in their body is more likely to develop heart disease or suffer a stroke. Obesity or overweight and other risk factors, such as high cholesterol and hypertension, increase the chance of type 2 diabetes.


Diabetics are more likely to develop cardiovascular disease at least 68% of diabetic people under 65 die from heart disease. People who have diabetes and are overweight, need to control the level of sugar in their blood so that worse consequences do not bother.

Contributing risk factors

Some of the factors listed below, combined with a modifiable risk factor, can help with a heart attack as well.


Some scientists have observed a relationship between stress in someone’s life and the risk of developing coronary heart disease. This is due to the fact that, under a lot of stress, a person can resort to items that help to relieve him, such as overeating, starting to smoke or smoking more than usual.


Ingestion of too much alcohol can increase blood pressure, as well as increasing the risk of diseases and conditions such as cardiomyopathy, stroke and irregular heartbeat.


A healthy diet is the key to preventing most diseases, including cardiovascular diseases. What you eat and how much you eat can directly affect modifiable risk factors, such as high cholesterol, hypertension and being overweight.

Use of illicit drugs

When using illicit drugs, such as cocaine, spasms in your coronary arteries can be more frequent and, consequently, generate a case of infarction.

Infarction Symptoms

Most of the cases of infarction do not present any symptoms. However, when they appear, they can be divided between the classics and the more atypical ones, which normally appear mostly in women. Regarding the duration, the symptoms can last from a few minutes to a few hours, and can appear, disappear and appear again.

Classical symptoms

  • Chest pain that can radiate to the left arm, neck, stomach and back;
  • Cold sweat;
  • Fainting.

Atypical symptoms (usually appear in women)

  • Motion sickness;
  • Vomiting;
  • Shortness of breathe;
  • Excessive fatigue;
  • Chest discomfort;
  • Arrhythmia.

Because they do not appear frequently in cases of infarction, these symptoms can be confused with those of other diseases. Therefore, it is necessary that, in the presence of any suspicion, you go straight to the emergency room.

Diagnosis and First Aid

If you suspect that you (or someone close to you) is having a heart attack, the first thing you should do is call 911 and ask for an ambulance. While you are waiting, it is important that you rest, so that your heart does not have to work unnecessarily. If you have aspirin at your fingertips and are not allergic to it – take one unit (300mg), as it helps to thin the blood and restore blood flow in the heart muscle.

Sometimes, a complication called ventricular arrhythmia can stop the patient’s heart from beating. If you find that the person who has the heart attack does not seem to breathe, does not move or does not respond to any kind of stimulus, you must start chest compressions in order to revive him.

How to perform a cardiac massage:

  1. Place one of your hands on the sternum, bone located right in the middle of the chest. That done, place your other hand on the first and cross your fingers with each other.
  2. Using all of your body weight (and not just that of your arms), press the person’s chest down by 5 to 6 cm.
  3. Repeat the procedure until the ambulance arrives.

When the ambulance arrives, any remaining diagnostic procedure will be done in an emergency room with a general practitioner. With the results of the exams and the analysis of the described symptoms, the patient will be referred to the heart disease specialist (cardiologist).

Tests that diagnose myocardial infarction


Some tests may be ordered by the cardiologist. Find out what they are:

Electrocardiogram (ECG)

Exam that identifies where the damage occurred and the intensity with which it hit the organ. The ECG has the function, basically, of measuring how fast your heart is beating and what is your rhythm (stable or irregular), in addition to recording the strength and the time with which the electrical signals pass through each part of the heart.


Through blood tests, the levels of certain cardiac enzymes that indicate damage to the heart muscle can be measured. By measuring these enzymes, the doctor is able to get a sense of the size of the infarction and approximately when it started. In addition to enzymes, troponins are also measured, that is, proteins found within cardiac cells that are released only when the cells are damaged by a lack of sufficient blood in the heart.


It is a type of imaging test that is used to find out how the heart is pumping blood, as well as areas where it is not being pumped properly. Echocardiography also shows which structures of the heart have suffered injuries from the infarction.


If the drugs do not relieve the symptoms of a heart attack, catheterization can be used by doctors. This test is used to directly view the blocked artery and help the specialist determine which treatment is best for that case.


The treatment for a case of infarction basically consists of mechanical / surgical procedures and the use of medications. Understand better:

Mechanical / surgical procedures

  • Defibrillation: when the patient suffers, during infarction, with a condition known as ventricular fibrillation (dangerous heart rate arrhythmia), the defibrillator can be used to control this irregularity;
  • Angioplasty: tube with a balloon at the tip that is inserted into the blocked artery, in order to unblock it;
  • Laser angioplasty: similar to angioplasty, with the difference that, instead of a balloon, the tube has a laser tip that opens the blocked artery;
  • Heart valve replacement surgery: the diseased heart valve is replaced by a healthy, but artificial one;
  • Atherectomy: very similar to angioplasty, in atherectomy the implanted catheter has a rotating shaver at its tip to cut the plaque that is blocking the artery;
  • Bypass surgery: treats blocked arteries and creates new passages for blood to circulate normally in the heart muscle;
  • Cardiomyoplasty: experimental procedure that aims to remove the skeletal muscles from the patient’s back or abdomen in order to be stimulated synchronously to the heart, causing the myocardium to be replaced or involved by them;
  • Heart transplantation: replacement of the diseased heart with a healthy one that was donated;
  • Minimally invasive cardiac surgery: it is an alternative to standard bypass surgery;
  • Radiofrequency ablation: a catheter with an electrode on the end is guided through the veins until it reaches the heart muscle and causes some cells to be destroyed in a very small area;
  • Stent procedure: a mesh tube is used to open an artery during an angioplasty;
  • Transmocardial revascularization: a laser is used to make a series of holes in the heart’s pumping chamber.

Infarction medications

  • Aspirin : if you have not taken the medicine while waiting for the ambulance, paramedics will administer a dose to your body, as it helps to maintain blood flow in an artery that is narrower;
  • Thrombolytics: medicines that help dissolve a blood clot that is blocking the passage of blood in the coronary arteries. The sooner you receive this medication, the greater the chances of survival and with less sequelae;
  • Antiplatelet agents: help prevent the formation of other clots and keep existing clots at their size. An example of a drug in this class is clopidogrel ;
  • Other blood thinning medications : medications like heparin can be administered to make your blood less “sticky” and likely to form clots;
  • Painkillers: to relieve your discomfort, morphine can be used;
  • Nitroglycerin : used to treat angina pectoris, nitroglycerin can help improve blood flow to the heart, as it dilates the vessels;
  • Beta-blockers: medicines that help to relax the heart muscle, decrease the heart rhythm and also the blood pressure, so that the organ can work more easily. Beta-blockers limit the amount of damage to the heart muscle, in addition to preventing future heart attacks;
  • Angiotensin-converting enzyme (ACE) inhibitors: reduce blood pressure and stress on the heart. One of the options that can be indicated is captopril .
  • Statins: used to decrease the level of LDL (“bad cholesterol”) and increase HDL (“good cholesterol”). It appears that many people who use drugs such as simvastatin or lovastatin , have decreased their chances of heart attack.


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained on this site is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.


In the post-infarction period, there must be a recovery period on the part of the patient. In it, several professionals will help you in physical and mental recovery, which consists of:

  • Gradually restore your physical shape so that you can resume your normal activities;
  • Reduce the risk of another episode of heart attack.


The post-infarction physiotherapy process must start at the hospital and it usually consists of the following exercises:

  • Breathing exercises to strengthen the lungs;
  • Muscle stretches;
  • Up and down stairs;
  • Exercises to improve your physical condition.

The intensity of all of them will depend a lot on the rehabilitation phase that the patient is already in.

Taking medication correctly

After a heart attack, your doctor will most likely prescribe some medications to control your blood flow or any of the risk factors you may have. Ideally, you should always know the names of these drugs, as well as taking them as prescribed.

Deal with your emotions

After a heart attack, feelings like fear, anger and depression may come to plague the patient. So, in order for this to be controlled and not go to an even higher level, consider discussing the situation with your doctor, friends and family. If you prefer, be part of cardiac rehabilitation groups, as they can be effective in helping you deal with everything that happened.


Having a healthy diet is synonymous with good health and prevention for several diseases, including another case of heart attack:

  • Salt, sugar and saturated fat: these three elements must be administered in small amounts, so that cholesterol, blood pressure and weight are controlled;
  • Foods rich in magnesium: foods such as nuts, beans and dark green vegetables stabilize the heart rate, thus preventing a heart attack;
  • Vitamins A, C and E (vitamin supplements are not indicated): fruits, vegetables and grains provide numerous antioxidant vitamins, which fight free radicals that can harm the heart in a dangerous way;
  • Omega-3: Omega-3 fatty acids decrease inflammation in the body, making the heart a healthier organ. Omega-3s can be found in foods such as olive oil, canola oil and some types of fish, such as salmon and tuna;
  • Root vegetables : vegetables like carrots lower a person’s cholesterol in the long run and reduce blood clotting.

Return to work

The return to your routine varies from person to person, since the intensity of work that each profession requires is different from each other. For example, if you work in an office, doing light activities during the day, your return can be made in up to two weeks. However, if your work is more intense, such as heavy manual labor, the payback may only be after several months.


According to the British Heart Foundation , the patient who has suffered a heart attack can return to his sex life as soon as he feels well enough, which usually takes four to six weeks after the event. It is important to keep in mind that having sex will not increase the chances of another heart attack happening.

To drive

If you have a heart attack and drive frequently, you need to report it to DETRAN. Most patients return to driving in about two weeks. However, if the case was very intense, you will probably be away from the activity for up to four weeks.

Contraceptive pill

Never use birth control pills if you have suffered a heart attack, as this type of medication is directly linked to increased blood clotting.


Like most diseases, if not treated as soon as possible and correctly, infarction can also cause several complications:

  • Arrhythmia , that is, abnormal heart rhythms;
  • Heart failure , temporary or chronic;
  • Heart rupture , often fatal;
  • Valve problems , causing leakage;
  • Erectile dysfunction due to stress and anxiety caused by the episode. About one in three men suffer from the problem.


Since there are modifiable risk factors, the ideal is to control them, because thus, the prevention of a heart attack is also done. This control is basically divided into three topics:

  1. If you are a smoker, try to quit;
  2. Check with your doctor for ways to control risk factors, which may be high blood pressure, high cholesterol, diabetes and obesity;
  3. A healthy diet and an active lifestyle help to prevent infarction, as they also help control certain risk factors.