What Is a Heart Attack?
More than a million Americans have heart attacks each year. Heart attacks are also called myocardial infarctions (MI). "Myo" means muscle, "cardial" refers to the heart, and "infarction" means death of tissue because of a lack of blood supply. This tissue death can cause lasting damage to your heart muscle..
Heart Attack Symptoms
Symptoms of a heart attack include:
- Discomfort, pressure, heaviness, tightness, squeezing, or pain in your chest or arm or below your breastbone
- Discomfort that goes into your back, jaw, throat, or arm
- Fullness, indigestion, or a choking feeling (it may feel like heartburn)
- Sweating, upset stomach, vomiting, or dizziness
- Severe weakness, anxiety, fatigue, or shortness of breath
- Fast or uneven heartbeat
Symptoms can be different from person to person or from one heart attack to another. Women are more likely to have symptoms like an upset stomach, shortness of breath, or back or jaw pain.
With some heart attacks, you won’t notice any symptoms (a "silent" myocardial infarction). This is more common in people who have diabetes.
Heart Attack Causes
Your heart muscle needs a constant supply of oxygen-rich blood. Your coronary arteries give your heart this critical blood supply. If you have coronary artery disease, those arteries become narrow, and blood can’t flow as well as it should. When your blood supply is blocked, you have a heart attack.
Fat, calcium, proteins, and inflammatory cells build up in your arteries to form plaques. These plaque deposits are hard on the outside and soft and mushy on the inside.
When the plaque is hard, the outer shell cracks. This is called a rupture. Platelets (disc-shaped things in your blood that help it clot) come to the area, and blood clots form around the plaque. If a blood clot blocks your artery, your heart muscle becomes starved for oxygen. The muscle cells soon die, causing permanent damage.
Rarely, a spasm in your coronary artery can also cause a heart attack. During this coronary spasm, your arteries restrict or spasm on and off, cutting off the blood supply to your heart muscle (ischemia). It can happen while you’re at rest and even if you don’t have serious coronary artery disease.
Each coronary artery sends blood to a different part of your heart muscle. How much the muscle is damaged depends on the size of the area that the blocked artery supplies and the amount of time between the attack and treatment.
Your heart muscle starts to heal soon after a heart attack. This takes about 8 weeks. Just like a skin wound, a scar forms in the damaged area. But the new scar tissue doesn’t move the way it should. So your heart can’t pump as much after a heart attack. How much that ability to pump is affected depends on the size and location of the scar.
What Do I Do if I Have a Heart Attack?
After a heart attack, you need quick treatment to open the blocked artery and lessen the damage. At the first signs of a heart attack, call 911. The best time to treat a heart attack is within 1 or 2 hours after symptoms begin. Waiting longer means more damage to your heart and a lower chance of survival.
Heart Attack Diagnosis
Emergency medical workers will ask you about your symptoms and do some tests.
Tests to diagnose a heart attack
Your doctor may order tests including:
- EKG. An EKG (also known as an electrocardiogram or ECG) can tell how much your heart muscle has been damaged and where. It can also monitor your heart rate and rhythm.
- Blood tests. Different levels of cardiac enzymes in your blood can indicate heart muscle damage. These enzymes are usually inside the cells of your heart. When those cells are injured, their contents -- including the enzymes -- spill into your bloodstream. By measuring the levels of these enzymes, your doctor can find out the size of the heart attack and when it started. Tests can also measure troponin levels. Troponins are proteins inside heart cells that are released when the cells are damaged by the lack of blood supply to your heart.
- Echocardiography. This imaging test can be used during and after a heart attack to learn how your heart is pumping and what areas aren’t pumping the way they should. The "echo" can also tell whether any parts of your heart (valves, septum, etc.) have been injured in the heart attack.
- Cardiac catheterization. You might need cardiac catheterization, also called cardiac cath, during the first hours of a heart attack if medications aren’t helping the ischemia or symptoms. The cardiac cath can give an image of the blocked artery and help your doctor decide on a treatment.
Heart Attack Treatment
Treatment begins right away, sometimes in the ambulance or emergency room.
What drugs are used to treat a heart attack?
Drug therapy aims to break up or prevent blood clots, stop platelets from collecting and sticking to the plaque, stabilize the plaque, and prevent more ischemia.
Take these medications as soon as possible (within 1 or 2 hours from the start of your heart attack, if possible) to limit heart damage.
Drugs used during a heart attack may include:
- Aspirin to stop blood clotting that may make the heart attack worse
- Other antiplatelet drugs, such as clopidogrel (Plavix), prasugrel (Effient), or ticagrelor (Brilinta) to stop clotting
- Thrombolytic therapy ("clot busters") to dissolve blood clots in your heart's arteries
- Any combination of these
Other drugs given during or after a heart attack help your heart work better, widen your blood vessels, lower your pain, and help you avoid life-threatening heart rhythms.
Are there other treatments for a heart attack?
- Cardiac catheterization. In addition to making a picture of your arteries, cardiac cath can be used for procedures (such as angiography or stent) to open narrowed or blocked arteries.
- Bypass surgery. You might have bypass surgery in the days after a heart attack to restore the blood supply to your heart.
Treatments don’t cure coronary artery disease. You can still have another heart attack. But you can take steps to make it less likely.
Tips for Heart Attack Prevention
The goal after your heart attack is to keep your heart healthy and lower your risk of having another heart attack. Take your medications as directed, make healthy lifestyle changes, and see your doctor for regular heart checkups.
Why do I need to take drugs after a heart attack?
You might take certain drugs after a heart attack to:
- Prevent blood clots
- Help your heart work better
- Prevent plaques by lowering cholesterol
Know the names of your medications, what they’re used for, and when you need to take them. Go over your medications with your doctor or nurse. Keep a list of all your medications, and take it to each of your doctor visits. If you have questions about them, ask your doctor or pharmacist.
What lifestyle changes are needed after a heart attack?
To keep heart disease from getting worse and to head off another heart attack, follow your doctor's advice. You might need to change your lifestyle, including:
When will I see my doctor again after I leave the hospital?
Make a doctor's appointment for 4 to 6 weeks after you leave the hospital following a heart attack. Your doctor will want to check your recovery. You might need an exercise stress test on a regular basis. These tests can help your doctor find or slow blockages in your coronary arteries and plan your treatment.
Call your doctor if you have symptoms such as chest pain that happens more often, gets stronger, lasts longer, or spreads to other areas; shortness of breath, especially while you’re resting; dizziness; or uneven heartbeats.