By Dr Ananya Mandal, MD
What is a heart attack?
Answer: A heart attack is a medical emergency. Heart attack occurs when the blood supply to part of the heart has been cut off due to a blockage in one or more of the coronary arteries. This lack of blood supply to the heart muscle starves it of oxygen, which can cause severe injury or even death of the heart muscle tissue. The medical term for heart attack is myocardial infarction (MI).
What is the cause of a heart attack?
Answer: One of the most common causes of heart attack is coronary artery disease, where the coronary arteries become hardened and narrowed due to atherosclerosis. Atherosclerosis refers to the build-up of fatty plaques or atheromas inside the walls of the arteries. These plaques are made up of platelets, clots and cholesterol. Over time, the thickened walls reduce blood flow through the coronary artery. In cases where a blood clot forms, the artery may become completely blocked. This leads to a heart attack. Another cause of heart attack is sudden severe spasm or tightening of the coronary artery that blocks the blood supply.
What are the risk factors for a heart attack?
Answer: Men aged over 45 years and women aged over 55 years are at a greater risk of heart attacks than younger individuals. Those with a family history of early heart disease and those belonging to certain ethnicities such as Africans and African-Caribbeans are also at a greater risk. People with a history of angina or other heart conditions are also at an increased risk. Other risk factors for heart attack include smoking, obesity and overweight, sedentary lifestyle, a diet rich in saturated fatty acids and trans fatty acids, high blood cholesterol and high blood pressure. Metabolic syndrome is a combination of high blood cholesterol, diabetes, obesity and high blood pressure. A person with metabolic syndrome is twice as likely to develop heart disease as someone without the syndrome.
What are the symptoms of a heart attack?
Answer: One of the main symptoms of heart attack is a heavy, painful compressed sensation across the chest. The pain may not be confined to the chest and can radiate to the arms (often the left arm), the neck, jaws and back. Other symptoms include weakness, dizziness, shortness of breath, nausea, vomiting and anxiety that is often described as an impending sense of doom.
Is it necessary to have all the symptoms to call for help?
Answer: No, not all symptoms described above are always present.
How common are heart attacks?
Answer: Heart attacks are very common worldwide. Each year, more than 1 million people in the USA have a heart attack.
Can a heart attack be prevented?
Answer: Some of the risk factors such as smoking, excessive alcohol consumption, obesity and overweight, sedentary lifestyle, and a diet rich in fatty acids, sugar and cholesterol can be modified to reduce the risk of heart attack. High blood pressure is another important risk factor for heart attack and patients with this condition should adhere to any treatment plan that has been made to reduce their blood pressure.
How is a heart attack diagnosed?
Answer: A heart attack diagnosis is based on the findings of an electrocardiogram (ECG). Blood tests to identify cardiac markers in the blood are also helpful. A nuclear heart scan uses radioactive tracers to diagnose the extent of damage to the heart. Cardiac catheterization and angiography is a confirmatory diagnostic test that shows the extent and site of coronary artery blockage.
How is a heart attack treated?
Answer: Heart attack is treated as a medical emergency. Ideally, the patient is initially given a tablet of aspirin (300mg) to chew on as soon as symptoms manifest. At this dose, the aspirin acts as an antiplatelet agent and thins the blood. It can reduce the risk of a heart attack. In addition, morphine or an opioid may be given to alleviate pain and oxygen may be administered via a mask.
Medications that may be used include thrombolytics and fibrinolytics to dissolve the blood clots and these are usually administered by injection.
Surgical procedures that are used to unblock the coronary artery include coronary angioplasty and coronary artery bypass graft.
What is the concern after recovering from a heart attack?
Answer: People who have had a heart attack are at a greater risk of another attack in the future. Therefore, it is very important to be aware of the risk factors, to take medication regularly and be ready to call for help if symptoms begin.
Reviewed by Sally Robertson, BSc
Last Updated: Jul 30, 2014