DENVER (KDVR) — Buffalo Bills safety Damar Hamlin suffered a cardiac arrest after making a tackle during the Monday Night Football game against the Cincinnati Bengals.

Hamlin’s heartbeat was restored on the field after CPR was performed and an automated external defibrillator was used, WXIX-TV in Cincinnati reported. The Bills said he is currently sedated at the hospital and listed in critical condition.

According to the American Heart Association, cardiac arrest is the abrupt loss of heart function in a person who may or may not have been diagnosed with heart disease. It can come on suddenly or in the wake of other symptoms.

How are they different?

The AHA said that people often use the terms cardiac arrest and heart attack interchangeably, but they are not the same.

A cardiac arrest is triggered by an electrical malfunction in the heart that causes an irregular heartbeat. With the pumping action of the heart disrupted, the heart cannot pump blood to the brain, lungs and other organs. Seconds after a cardiac arrest, a person will become unresponsive and cannot breathe, or is only gasping.

“Cardiac arrest may be reversed if CPR is performed and a defibrillator shocks the heart and restores a normal heart rhythm within a few minutes,” the AHA explained.

If a cardiac arrest is not treated within minutes, a person will die, the AHA said.

In contrast, a heart attack happens when blood flow to the heart is blocked.

“A blocked artery prevents oxygen-rich blood from reaching a section of the heart. If the blocked artery is not reopened quickly, the part of the heart normally nourished by that artery begins to die,” the AHA said.

The AHA said cardiac arrest is an electrical problem, like an irregular heartbeat, and a heart attack is a circulation problem, like a blocked artery.

“These two distinct heart conditions are linked. Sudden cardiac arrest can occur after a heart attack, or during recovery. Heart attacks increase the risk for sudden cardiac arrest. Many heart attacks don’t immediately lead to sudden cardiac arrest, but when sudden cardiac arrest occurs, heart attack is a common cause. Other heart conditions may also disrupt the heart’s rhythm and lead to sudden cardiac arrest. These include a thickened heart muscle (cardiomyopathy), heart failure, arrhythmias, particularly ventricular fibrillation, and long Q-T syndrome,” the AHA explained.

The AHA said more than 356,000 cardiac arrests happen outside of hospitals in the United States each year.