What is Myocardial Infarction?

Myocardial infarction or Heart attack is caused by interruption in blood supply to a part of heart, one of the most vital organs in our body. This interruption of blood supply results in death of the cardiac musculature compromising its function. Myocardial infarction is one of the most common causes of death in the current decade.

Blood supply of heart

Like all organs, the heart needs a constant supply of oxygen-rich blood. A system of arteries and veins called the Coronary circulation supplies the heart muscle (myocardium) with oxygen-rich blood and then returns oxygen-depleted blood to the right atrium. The right coronary artery and the left coronary artery deliver oxygen-rich blood to the heart muscle. These two arteries branch into other arteries, supplying to whole of the heart. The cardiac veins collect blood from the heart muscle and empty it into a large vein on the back surface of the heart, called the coronary sinus, which returns the blood to the right atrium. Any obstruction to this blood supply results in the common condition, heart attack or myocardial infarction.

Blockage of a coronary artery, most commonly due to atherosclerosis of the supplying arteries, deprives the heart muscle of blood and oxygen, causing injury to the heart muscle. Injury to the heart muscle causes chest pain and chest pressure sensation (tightness). If blood flow is not restored to the heart muscle within 20 to 40 minutes, irreversible death of the heart muscle will begin to occur.

Risk factors for heart attack and coronary artery disease include:

• Age over 65 years
• Male gender
• History of Diabetes mellitus
• Family history of coronary artery disease(genetic or hereditary factors)
• High blood pressure
• Tobacco smoking
• Alcohol consumption
• Obesity
• Unhealthy cholesterol levels, especially high LDL (“bad”) cholesterol and low HDL (“good”) cholesterol
• Unhealthy living habits – sedentary life, intake of junk foods.
• Pschycological stress and physical strain

Symptoms of Myocardial Infarction

Classical symptoms of acute myocardial infarction include sudden constricting type chest pain, which may move from your chest to your left arm, shoulder, neck, jaw or back. The pain can be severe or mild. It can feel like a tight band around the chest, bad indigestion, something heavy sitting on your chest or squeezing, heavy pressure. The pain usually lasts longer than 20 minutes. Rest and a medication do not completely relieve the pain of a heart attack. Symptoms may also go away and come back. Other symptoms of a heart attack include Anxiety (commonly explained as a feeling of impending doom, Cough, Fainting, Light-headedness, dizziness, Nausea or vomiting, Palpitations (feeling like your heart is beating too fast), Shortness of breath, Sweating, which may be extreme. Some people (the elderly, people with diabetes, and women) may have little or no chest pain. Or, they may experience unusual symptoms (shortness of breath, fatigue, weakness). A “silent heart attack” is a heart attack with no symptoms.