A heart attack occurs when the blood flow to the heart is blocked. The blockage is most commonly caused by a buildup of cholesterol, fat, and other substances. These form a plaque in the arteries that feed the heart (coronary arteries).
The plaque breaks away eventually and forms a clot. The interrupted blood flow can destroy or damage part of the heart muscle.
A heart attack (also called myocardial infarction), can be fatal, but treatment has dramatically improved over the years. It is crucial to call emergency medical services or 911 for help if you think you are having a heart attack. If a heart attack is caught early enough it is treatable through procedures and medications such as blood thinners.
Common signs and symptoms of heart attacks include:
- Nausea, heartburn, indigestion or abdominal pain
- Cold sweat
- Pressure, tightness, pain or a squeezing/aching sensation in your arms or chest that can spread to your jaw, neck, or back
- Lightheadedness or sudden dizziness
- Shortness of breath
Heart attack symptoms vary
Not everyone who has a heart attack will have the same symptoms or have the same symptom severity. Some people will have a mild pain; others have more severe pain. Some have no symptoms; for others, the first sign will be sudden cardiac arrest. However, the more of these signs and symptoms that occur, the more likely it is you’re having a heart attack.
Some heart attacks strike very suddenly, but most people have warning signs and symptoms hours, days, or even weeks in advance. The earliest warning might be recurrent chest pressure or pain that’s triggered by exertion and relieved by rest. Angina is caused by a temporary decrease in blood flow to the heart.
A heart attack happens when one or more of your coronary arteries get blocked. Over time, a coronary artery can become narrow from the buildup of various substances including cholesterol. This condition, called coronary artery disease, causes a majority of heart attacks.
While a heart attack is happening, one of these plaques may rupture and spill cholesterol or other substances into the bloodstream. A blood clot forms where the rupture happened. If it’s large enough, the clot can block the blood’s flow through the coronary artery. This starves the heart muscle of nutrients and oxygen.
You may have a complete or partial blockage. A complete blockage means that you have had an ST elevation myocardial infarction (STEMI). A partial blockage means you have experienced a non-ST elevation myocardial infarction (NSTEMI). Diagnostic steps and treatment can be different depending which you’ve experienced.
Another cause of heart attacks is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle. If you use tobacco and illicit drugs like cocaine, it can cause a life-threatening spasm.
Ideally, your doctor will screen you during regular physical exams for risk factors that can lead to heart attacks.
If you’re in an emergency setting for heart attack symptoms, you’ll be asked about your symptoms and have your blood pressure, temperature, and pulse checked. You’ll be hooked up to a heart monitor and have tests to see if you’re having a heart attack.
These tests include:
- Blood tests. Certain heart proteins will slowly leak into your blood after heart damage resulting from a heart attack. Emergency room doctors will take blood samples to test for the presence of these enzymes.
- Electrocardiogram (ECG). This is the first test done to diagnose a heart attack. It records the electrical activity of the heart via electrodes attached to the skin. Impulses get recorded as waves either displayed on a monitor or printed to paper. As injured heart muscle doesn’t conduct electrical impulses in a normal way, the ECG may show that a heart attack is in progress or has occurred.
If you are having or have had a heart attack, doctors will take steps to treat your condition immediately. You may also have these additional tests:
- Echocardiogram. Sound waves directed at your heart from a transducer (a wandlike device) held on your chest bounce off your heart. They are then processed electronically to provide video images of your heart. An echocardiogram can help to identify whether an area of your heart isn’t pumping normally due to damage.
- Chest X-ray. An X-ray image of your chest allows your doctor to check on the size of your heart and blood vessels. They can also look for fluid in your lungs.
- Cardiac CT or MRI. These are tests that can be used to diagnose heart problems, including the extent of damage from heart attacks.
- Exercise stress test. In the days or weeks following your heart attack, you may also have a stress test to measure how your blood vessels and heart respond to exertion. You can also walk on a treadmill or pedal a stationary bike while attached to an ECG machine. You might also receive a drug intravenously that stimulates your heart in a way similar to exercise.
- Coronary catheterization (angiogram). A liquid dye gets injected into the arteries of your heart through a catheter that’s fed through an artery, generally in the groin or leg, to the arteries in your heart. The dye will make the arteries visible on X-ray, revealing areas of blockage.
Heart attack treatment at a hospital
Every minute following a heart attack, more tissue dies or deteriorates. Restoring blood flow quickly helps to prevent heart damage
Coumadin is one of the most common blood thinners.
Medications (including blood thinners) that are given to treat a heart attack include:
- Aspirin. The 911 operator may tell you to take aspirin. Emergency medical personnel may also immediately give you aspirin. Aspirin is known as a blood thinner and reduces blood clotting which helps maintain blood flow through a narrowed artery.
- Thrombolytics. These medications, colloquially called clotbusters, help to dissolve a blood clot that is blocking flow to the heart. The earlier you get a thrombolytic drug after a heart attack, the greater your chance of surviving with less heart damage.
- Antiplatelet agents. Emergency room doctors might give you other medications known as platelet aggregation inhibitors (these are also blood thinners) that help prevent new clots and keep existing clots from getting larger.
- Other blood thinners. You’ll likely be given other medications like heparin to make your blood less “sticky” and less likely to form clots. Heparin is administered either intravenously or by injection under your skin.
- Pain relievers. You may be given a pain reliever like morphine.
- Nitroglycerin. This drug is used mainly to treat chest pain (angina). It can help improve blood flow to the heart by dilating the blood vessels.
- Beta blockers. These medications help to relax your heart muscle, slowing your heartbeat and decreasing blood pressure which makes your heart’s job easier. Beta blockers can limit the amount of damage to heart muscles and prevent future heart attacks.
- ACE inhibitors. These medications lower blood pressure and reduce the stress on the heart.
- Statins. These drugs help to control your blood cholesterol.
Surgical and other procedures
In addition to drugs, you could also have one of these procedures to treat your heart attack.
- Coronary angioplasty and stenting. In this procedure, also known as percutaneous coronary intervention (PCI), doctors put a catheter through an artery in the wrist or groin through to a blocked artery in your heart. If you’ve had a heart attack, this procedure is usually done immediately after a cardiac catheterization.
This catheter has a special balloon that is put into position and then briefly inflated to open a blocked coronary artery. Then a metal mesh stent may be inserted to keep the artery open for the long term, restoring blood flow to the heart. Depending on your condition your stent may be coated with a slow-releasing medication to help keep the artery open.
- Coronary artery bypass surgery. In some cases, doctors will perform emergency bypass surgery at the time of the heart attack. If possible however, you may have bypass surgery after your heart has had time to recover from the heart attack. Bypass surgery involves sewing arteries or veins in place beyond a narrowed or blocked coronary artery, allowing blood flow to the heart to bypass the narrowed section. After blood flow to your heart is restored and you are in a stable condition, you will likely remain in the hospital for several days.
Many hospitals offer programs that might start while you’re in the hospital and continue for a couple of weeks to months after you return home. Cardiac rehabilitation programs usually focus on 4 main areas: lifestyle changes, gradual return to your normal activities, medications, and emotional issues.
It’s very important to fully participate in this program. People who attend cardiac rehab after experiencing a heart attack in general live longer and are less likely to have complications from the heart attack or another heart attack. If cardiac rehab is not recommended during your stay at the hospital, ask your doctor about it.