Myocardial Infarction
Myocardial infarction, commonly known as a heart-attack, is a medical emergency.
What is myocardial infarction?
Myocardial infarction, commonly known as a heart-attack, is a medical emergency where the heart muscle (myocardium) begins to die because it isn’t getting enough blood flow. The myocardium is a type of muscle tissue that forms the heart. Cardiac (heart) muscle tissue contracts and releases involuntarily. It is responsible for keeping the heart pumping blood around the body.
Acute myocardial infarction (AMI) is myocardial necrosis resulting from acute obstruction of a coronary artery.
What causes myocardial infarction?
Myocardial infarction occurs when the flow of blood to the heart is severely reduced or blocked. This is usually due to a buildup of fat, cholesterol and other substances in the heart (coronary) arteries. The fatty, cholesterol-containing deposits are called plaques. Atherosclerosis is the process of plaque buildup. Sometimes, a plaque can rupture to form a clot that blocks blood flow.
A blocked artery can cut off the blood supply to certain areas of the heart. Eventually, the cardiac muscle tissue in these areas will start to die. The death of cardiac muscle tissue can also occur when the heart’s oxygen demand exceeds the oxygen supply. This causes the release of cardiac proteins such as troponin into the bloodstream.
What are the symptoms of myocardial infarction?
Symptoms of a heart attack vary. Some people have mild symptoms. Others have severe symptoms. Some people have no symptoms.
Common heart attack symptoms include:
- Chest discomfort. Chest pain that may feel like pressure, tightness, pain, squeezing or aching.
- Discomfort in other areas of the upper body. Pain or uneasiness that spreads to the shoulder, arm, back, neck, jaw, teeth or sometimes the upper belly.
- Shortness of breath.
- Cold sweat.
- Nausea or vomiting.
- Heartburn or indigestion.
- Light-headedness or sudden dizziness.
- An overwhelming feeling of anxiety (similar to a panic attack).
As with men, women’s most common heart attack symptom is chest pain or discomfort. But women may experience other symptoms that are typically less associated with heart attack, such as shortness of breath, nausea/vomiting, and back/arm or jaw pain.
Sometimes, the first symptom sign of a heart attack is unexpected cardiac arrest that strikes suddenly. However, many people have warning signs and symptoms hours, days or weeks in advance. Chest pain or pressure that keeps happening and doesn’t go away with rest may be an early warning sign. This is caused by a temporary decrease in blood flow to the heart.
Causes of chest pain
Chest pain (angina) has many causes, including problems in the heart, lungs or digestive system. Some causes are life-threatening while others aren’t. Chest pain is difficult to diagnose because it has so many causes. Healthcare providers start by looking for life-threatening causes first.
Some heart problems include heart attack (lack of blood to the heart), coronary artery disease (CAD, a narrowing or blockage in the heart’s arteries), pericarditis (inflamed sac around the heart) or heart rhythm problems.
Gastroesophageal reflux disease (GERD or chronic heartburn) is the most common cause of chest pain. Other digestive system causes of chest pain are ulcers (sores in the stomach lining), muscle spasms in the oesophagus (food tube), esophagitis (inflamed food tube), gallstones (hardened digestive fluid), gastritis (inflamed stomach lining) and pancreatitis (inflamed pancreas).
Lung causes of chest pain include pulmonary embolism (blood clot in the lung), chronic obstructive pulmonary disease (COPD or lung disease), pneumonia (lung infection), pleuritis (inflamed lining of the lungs), pneumothorax (collapsed lung), pulmonary hypertension (high blood pressure in the pulmonary arteries) and asthma (narrow airways).
Other causes, for example, include muscle strains, panic attacks and a rib fracture (broken rib).
When to seek medical help for chest pain
Sudden severe chest pain or any unexplained chest pain that lasts more than a few minutes may be serious. Especially if accompanied by symptoms such as pain spreading to the arms, back, neck, or jaw, shortness of breath, tightness in the chest, or pain that starts with nausea, vomiting, and sweating.
Any person experiencing chest pain should consult a healthcare professional.
