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Dr. David L. Brown, of Medical City Dallas Hospital and Baylor Regional Medical Center at Plano, discusses types of heart attack.
In the movies, when someone has a heart attack, that person clutches his chest or arm and falls to the ground. Some people have exactly that experience. But it’s also important to know that
- Not all heart attacks have the same symptoms or severity, and
- Heart disease is the number one cause of death for women as well as men.
If you’ve had a heart attack, you know firsthand that Hollywood misses a lot of the details, including the hard physical and emotional work it takes to recover afterward.
Ultimately, the seriousness of the heart attack is judged by the amount of heart muscle that is permanently damaged. Your cardiologist will assess this damage through use of echocardiography, which is an ultrasound of the heart. Treatment of a heart attack will depend on the type and severity of the heart attack.
Several types of heart attacks are discussed below, as well as non-heart-related sources of chest pain. Remember, if you are experiencing symptoms of a heart attack, dial 911. Just because heartburn, for example, can produce some of the same symptoms doesn’t mean you should assume it is the less serious cause rather than the more serious condition. Every minute you delay if it is a heart attack could result in permanent heart muscle damage or increased risk of death.
STEMI Heart Attacks
An ST-segment elevation myocardial infarction (STEMI) is a serious form of heart attack in which a coronary artery is completely blocked and a large part of the heart muscle is unable to receive blood. “ST segment elevation” refers to a pattern that shows up on an electrocardiogram (EKG).
This type of heart attack requires immediate, emergency revascularization which restores blood flow through the artery. This revascularization is achieved either with drugs in the form of thrombolytics (clot busters), which are given intravenously, or mechanically with angioplasty – a treatment using thin, flexible tubes called catheters to open the closed artery.
These catheters are positioned at the beginning of the coronary arteries (the arteries of the heart), and contrast dye is injected through them to enable the interventional cardiologist to gather images of any blockage in the coronary arteries. Very thin wires (guidewires) are then advanced beyond the blockage and the clot is sucked out and/or a small balloon is opened to push the blockage out of the way. A stent– a metal, mesh tube – is often inserted at the same time to permanently prop the cleared artery open to allow blood to flow through.
NSTEMI Heart Attacks
A non-ST segment elevation myocardial infarction (NSTEMI) is a type of heart attack that does not show a change in the ST segment elevation on an electrocardiogram and that results in less damage to the patient’s heart. However, these patients will test positively for a protein called troponin in their blood that is released from the heart muscle when it is damaged. In NSTEMI heart attacks, it is likely that any coronary artery blockages are partial or temporary.
Treatment for an NSTEMI heart attack consists of medication and evaluation for whether a blockage is present that should be treated with medication only, cleared through angioplasty or treated with cardiac bypass graft surgery.
Coronary Artery Spasm
A coronary artery spasm is when the artery wall tightens and blood flow through the artery is restricted – potentially leading to chest pain, or blood flow is cut off all together – causing a heart attack. Coronary artery spasm comes and goes. Because there may not be a build-up of plaque or a blood clot in the artery, a coronary artery spasm may not be discovered by an imaging test called an angiogram that is typically performed to check arteries for blockages.
Treatment for a coronary artery spasm consists of medications such as nitrates and calcium channel blockers.
Demand ischemia is another type of heart attack for which blockages in the arteries may not be present. It occurs when a patient’s heart needs more oxygen than is available in the body’s supply. It may occur in patients with infection, anemia, or tachyarrhythmias (abnormally fast heart rates). Blood tests will show the presence of enzymes that indicate damage to the heart muscle.
Cardiac Arrest (not a heart attack)
In cardiac arrest, a person’s heart stops beating. Cardiac arrest is not the same thing as a heart attack, but it is worth discussing alongside heart attack. Cardiac arrest can occur due to a heart attack, but cardiac arrest can also occur as a primary event. In other words, cardiac arrest can also occur for other reasons besides a blockage in the artery. These other reasons include electrolyte disturbances, such as low or high potassium or low magnesium, congenital abnormalities, or poor pumping function of the heart.
In a heart attack, a person’s heart keeps beating. A heart attack can cause life-threatening arrhythmias (abnormal heart rhythms), like ventricular tachycardia (VT) or ventricular fibrillation (VF). These arrhythmias result in cardiac arrest within a few minutes because the heart is not pumping blood to the lungs to pick up vital oxygen that circulates back to the heart and to the body.
Seconds count in treating both heart attack and cardiac arrest. With cardiac arrest, the odds of survival go down by about 10 percent for every minute until the person is resuscitated. After 10 minutes the risk of permanent brain injury is very high.
Initial treatment will consist of cardiopulmonary resuscitation (CPR) and defibrillation – delivery of an electrical shock to restore the heart’s rhythm. For people who are resuscitated and have a heartbeat but do not regain consciousness, hypothermia protocols are sometimes used, where the body is cooled for 24 hours then gradually warmed. This has been shown to improve the odds of a good neurological outcome for those patients.