Acute myocardial infarction is one of the most dangerous diseases ever. It occurs when one of the arteries that supply blood to the heart becomes blocked. During the blockage of the artery, there is a risk of cardiac arrest and death, and more and more heart tissue dies.

The incidence of acute myocardial infarction increases with age, being more common in men. Other risk factors for its occurrence include hereditary burden, smoking, long-term untreated high blood pressure and elevated cholesterol levels. As a rough guide, the risk can be calculated according to the SCORE scoring system. Below is the risk table for the Czech Republic.

Percentage risk of cardiac event for a particular individual in the next ten years, depending on age, sex, systolic blood pressure, cholesterol level and smoking. Adapted from the European Society of Cardiology Recommended Practice.

It is best to prevent myocardial infarction. If you quit smoking, treat high blood pressure or high cholesterol levels, you reduce your risk of having a myocardial infarction. Reducing blood pressure and cholesterol levels can often be achieved through a healthy lifestyle with plenty of physical activity and a moderate and balanced diet.

If a myocardial infarction does occur, the emergency medical service should be contacted as soon as possible. It is a race against time and calling the ambulance in time can save a life and preserve as much heart tissue as possible. Paramedics can restore cardiac activity in the case of cardiac arrest and, after transport to a cardiac centre, also restore flow through the closed heart artery and stop the heart tissue from dying.

How to recognize an acute myocardial infarction? The main symptom is chest pain. This pain can take many forms, and sometimes the nature of the pain makes it difficult for the doctor to determine whether it is a dangerous myocardial infarction or another less dangerous cause of pain. Myocardial infarction pain is often dull, pressing, located in the middle of the chest or between the shoulder blades, and is accompanied by a feeling of vomiting and bad breath. If the chest pain is stabbing, on the left side of the chest, or tied to a breath, it may not be a heart problem.

*Typical distribution of chest pain in myocardial infarction*

To diagnose myocardial infarction, it is necessary to record an ECG. This can be done by an ambulance crew, GP or hospital emergency department. However, often the ECG picture may not be typical and the diagnosis is only made by taking blood. The first signs of damage to the heart appear in the blood 3 hours after the start of the heart attack.

*ECG curve in a patient with left ventricular inferior wall myocardial infarction*

If a myocardial infarction is suspected, drugs to reduce blood clotting are given and the patient is taken to the cardiac centre. There are cardiac centres in all regional cities and they provide a 24-hour catheterisation room with a team consisting of a specialist interventional cardiologist, a ward nurse and an X-ray technician. In the event of persistent signs of a heart attack, the patient undergoes a coronary artery catheterisation examination and, if a blockage or narrowing is confirmed, the artery is occluded and a stent is placed in the treatment site to prevent reclosure.

*Coronarogram with the right coronary artery closed (left part of the picture), final image after catheterization (right part of the picture)*

After coronary artery occlusion, the patient is transferred to the intensive care unit of the cardiac centre. A period of healing begins for the heart muscle, when there is still an increased risk of cardiac arrest and the patient must be monitored for at least two days. Treatment with drugs to reduce blood clotting is continued and treatment with drugs to lower cholesterol and reduce heart rate and blood pressure is started.

*Vital signs monitoring in the intensive care unit*

In the first stage, on admission and repeatedly in the following days, an ultrasound examination of the heart, called echocardiography, is performed. It allows the dimensions and function of the individual heart compartments to be quickly and painlessly visualised and the function of the valves to be assessed. It focuses in particular on the function of the left ventricle and assesses the extent of damage to it from the infarction. Possible complications of infarction such as mitral valve dysfunction or rupture of the left ventricular wall or interventricular septum are actively sought.

Uncomplicated hospitalization lasts approximately 4-5 days. After a myocardial infarction, it is necessary to take simultaneously two drugs to reduce blood clotting, blocking the function of platelets - acetylsalicylic acid and one of the following drugs - clopidogrel or ticagrelor. This so-called dual antiplatelet therapy prevents clot formation in the coronary arteries and at the site of the stent, if one has been used. Dual antiplatelet therapy is recommended for 1 year, but can be shortened to 1-3 months if necessary. Thereafter, the patient is switched to lifetime treatment with only one agent, namely acetylsalicylic acid.

All patients after a myocardial infarction are recommended to take a drug from the statin group. Statins lower cholesterol levels and have been shown to prolong life in patients after myocardial infarction. If blood pressure is high, it is controlled with heart rate slowing drugs - beta blockers, or in combination with drugs that affect the renin-angiotensin-aldosterone system. LDL cholesterol is checked regularly by blood sampling and it is recommended to achieve a level below 1.4 mmol/l. If this level is not achieved with the maximum dose of statin, cholesterol-lowering agents are gradually added in other ways. The target home blood pressure is up to 130/80 mmHg.

*Recommendations for long-term care after acute myocardial infarction from the European Society of Cardiology*

Every patient who has had a myocardial infarction should be followed by an outpatient cardiologist. He or she adjusts medications and dosages to achieve recommended levels of LDL cholesterol and blood pressure, actively looks for signs of coronary artery narrowing such as chest pain or shortness of breath, and motivates the patient to maintain a healthy lifestyle.

Acute myocardial infarction

Atrial fibrillation