08/07/2014 11:19 am ET Updated Oct 07, 2014

Heart Attack Treatment: Timing Is Everything

Annapoorna Kini, M.D.
Professor of Medicine, Cardiology

Icahn School of Medicine at Mount Sinai
Director of The Cardiac Catheterization Laboratory
The Mount Sinai Hospital

When it comes to treatment for heart attack, minutes matter. Cardiologists have a saying, "Time is myocardium." Simply put, the faster you receive treatment, the more your heart muscle (myocardium) can be preserved and the less damaged your heart will be.

There are two types of heart attack (also known as myocardial infarction, or MI): ST-segment elevation MI and non-ST-segment elevation MI. Each is a life-threatening emergency requiring immediate medical attention.

ST-Segment Elevation MI (STEMI)
In STEMI, the more serious type of heart attack, a clot completely blocks the coronary artery, cutting off all blood supply to the heart and damaging a large area of heart muscle. When this happens, individuals often will experience the typical heart attack symptoms most people recognize:
• Chest pressure;
• Sweating;
• Nausea;
• Chest pain radiating to the jaw, neck and arm.

However, these symptoms don't always occur with heart attack; instead, many people (especially women and the elderly) may experience the following atypical symptoms:
• Not feeling well (lethargy);
• Indigestion;
• Fatigue;
• Shortness of breath;

In either case, that is the time to call 9-1-1.

Non-ST-Segment Elevation MI (NSTEMI)
Less severe than STEMI, this type of heart attack is caused by a partial blockage in the coronary artery, decreasing (but not stopping) blood flow to the heart. Individuals experiencing NSTEMI may have the typical or, more commonly, atypical symptoms mentioned above.

Diagnosis and Treatment
If 9-1-1 is called, the paramedics will perform an electrocardiogram (EKG), a painless test used to check the electrical activity in the patient's heart, to help determine the type of heart attack. Depending on the results, treatment with aspirin, pain medication, and sometimes blood thinners can begin in the ambulance before the patient arrives at the hospital.

If the EKG shows a characteristic called ST-segment elevation, it means the patient is experiencing STEMI and must be rushed to the cardiac catheterization laboratory for emergency treatment. With the aim of saving the patient's life and reducing damage to the myocardium, doctors there will perform angioplasty, a procedure used to open the blocked artery and restore oxygen-rich blood flow to the heart.

During angioplasty, an interventional cardiologist threads a catheter (thin tube) with a tiny balloon at its tip through a blood vessel in the arm or groin up to the blocked artery. The balloon is then temporarily inflated to widen the artery and restore blood flow to the heart muscle. The interventional cardiologist also will likely place a permanent stent, or small wire mesh tube, into the artery to prop it open. Often, doctors will use a drug-coated stent, which a large-scale research trial has shown to reduce the rate of subsequent complications, such as re-blockage of the artery (restenosis).

If the EKG shows no ST-segment elevation, the patient will undergo a blood test to measure the level of a cardiac enzyme that reflects damage to the heart muscle. A positive blood test indicates a non-ST heart attack (NSTEMI), and the patient will be taken to the cardiac catheterization lab for an angiogram, a test that uses dye and X-rays to take pictures of the heart arteries. If the doctors see a blockage, they will go ahead and treat it with angioplasty and possibly a stent. Sometimes, if it is a minor blockage, they will treat the patient with medication only.

Recovery and Prevention
Patients usually leave the hospital after two or three days -- but treatment doesn't stop there. If you have suffered a heart attack, modifying your lifestyle is crucial to recovering from and reducing your chances of having another heart attack. Such changes may include:
• Eating a heart-healthy, low-cholesterol diet -- more vegetables and white meat, less red meat and fewer fried foods;
• Losing weight;
• Stopping smoking;
• Exercising. If you already exercise, do more; otherwise, you should at least walk from 30 to 60 minutes three to four times a week -- or daily, if possible.

In addition, you may have to take certain medications, including aspirin, blood thinning medication, statin medication to lower cholesterol levels, and/or blood pressure medication.

If your health insurance approves, cardiologists recommend participating in a cardiac rehabilitation program. Lasting six weeks or more, cardiac rehab takes place in a supervised setting where medical staff will tailor a physical activity program to patients' needs, monitor their blood pressure and heart rate during exercise, and offer counseling and education.

A Final Word
Heart disease -- not cancer -- is the No. 1 killer of both men and women in the United States. If you experience either the typical or atypical symptoms of heart attack mentioned above, seek medical attention immediately. Women, especially, need to pay attention to the atypical heart attack symptoms, as they often don't experience the same classic symptoms as men. The American Heart Association advises people to not wait more than five minutes before calling for help. Yes, it is an emergency, and yes, you should call 9-1-1. Your life may depend on it.