Heart attack vs. cardiac arrest: What is the difference?

Cardiac arrest, sometimes called sudden cardiac arrest, means that your heart suddenly stops beating. This cuts off blood flow to the brain and other organs. It is an emergency and is deadly if not treated immediately.

Cardiac arrest is quick and drastic: You suddenly collapse, lose consciousness, have no pulse, and are not breathing. Right before it happens, you could be very tired, dizzy, weak, short of breath, or sick to your stomach. You may pass out or have chest pain. But not always. Cardiac arrest can happen with no warning signs at all.

Your heart has an electrical system that keeps it beating regularly. Cardiac arrest can strike if the electrical signals go haywire and cause an irregular heartbeat, or arrhythmia. There are different types of arrhythmias, and most are not dangerous. One called ventricular fibrillation triggers cardiac arrest the most. If this happens, the heart cannot pump enough blood to your body. That is life-threatening within minutes.

Many people who have cardiac arrest also have coronary artery disease. Often, that is where the trouble starts. Having coronary artery disease means less blood flows into your heart. This can lead to a heart attack that damages your heart's electrical system.

Cardiac arrest can also happen for other reasons, including: major blood loss or severe lack of oxygen; intense exercise, if you have heart problems; too high levels of Potassium or Magnesium, which could lead to a deadly heart rhythm; your genes. You may inherit certain arrhythmias or a tendency to get them; changes to your heart's structure. For instance, an enlarged heart or changes caused by an infection.

Unlike cardiac arrest, your heart does not usually stop during a heart attack. Rather, blood flow is blocked in a heart attack, so your heart does not get enough oxygen. That can kill some of the heart muscle. But the two are linked: The scar tissue that grows as you recover from a heart attack can mess with the heart's electrical signals and could put you at risk. And a heart attack itself can sometimes trigger cardiac arrest.

Cardiac arrest strikes suddenly. It is an instant crisis. Heart failure is different. It is a condition where your heart gets weaker over time until it cannot send enough blood and oxygen around your body. When your cells do not get enough of these nutrients, your body does not work as well. You may find it hard to catch your breath when you do simple things like carry groceries, climb stairs, or even walk.

It is more likely if you: have coronary artery disease (this is the biggest risk); are a man; have had arrhythmias or cardiac arrest, or someone in your family has; smoke or abuse drugs or alcohol; have had one or more heart attacks; have diabetes, high blood pressure, or heart failure; are obese.

If you have cardiac arrest, you need immediate treatment with a defibrillator, a machine that sends an electric shock to the heart. This shock sometimes can get your heart to beat normally again. But it must be done within minutes to help.

The doctors will try to find out what caused your cardiac arrest and treat the problem. If you have coronary artery disease, you may get a bypass or a procedure called angioplasty to open narrowed or blocked arteries in your heart. You may also get medicines and advice for lifestyle changes to lower your chances of having it again.

Source: Web MD