What to expect after calling 911 for chest pain, from the June 2016 Harvard Heart Letter

Every 43 seconds, someone in the United States has a heart attack. Getting to the hospital quickly is just one reason why people should call 911 if they have chest pain or other heart attack symptoms, according to the June 2016 Harvard Heart Letter.

"If you're having a heart attack, there are two reasons why you want to be in an ambulance," says Dr. Joshua Kosowsky, assistant professor of emergency medicine at Harvard Medical School. One is that in the unlikely event of cardiac arrest, the ambulance has the equipment and trained personnel to restart a person's heart. Cardiac arrest, which results from a malfunction of the nerves that stops the heart's pumping ability, is fatal without prompt treatment. However, most heart attacks do not cause cardiac arrest, Dr. Kosowsky stresses. "It's rare, but it's certainly not a risk you want to take while you're driving or riding in a car."

The other reason to travel via ambulance is that in many places in the United States, if a person calls 911 complaining of chest pain, the dispatcher will send paramedics who are trained to perform an electrocardiogram (ECG). This simple, painless test records the heart's electrical activity through 12 small electrodes placed on the chest, arms, and legs. A six-second recording can then be transmitted to the receiving emergency department, which can help speed up the treatment once the person arrives at the hospital.

At the hospital, a doctor interprets the ECG, which will reveal whether the person is having a major heart attack, in which an artery feeding the heart is blocked and choking off the blood supply to part of the heart's muscle. This usually creates a distinct signature on the ECG and warrants quick treatment to open the blocked artery.

A person with a suspected heart attack will also get a blood test to measure troponin, a protein that rises in response to heart muscle damage. Other possible tests include a chest x-ray to look for alternative causes of chest discomfort, such as pneumonia or heart failure.

Heart attack symptoms

•Tightness, pressure, squeezing, stabbing, or dull pain, most often in the center of the chest

•Pain that spreads to the shoulders, neck, or arms

•Irregular or rapid heartbeat

•Cold sweat or clammy skin

•Lightheadedness, weakness, or dizziness

•Shortness of breath

•Nausea, indigestion, and sometimes vomiting

Read the full-length article: "When chest pain strikes: What to expect at the emergency room"