The difference between cardiac arrest and a heart attack is cardiac arrest happens when the heart malfunctions and suddenly stops beating, and a heart attack happens when blood flow is restricted to the heart, according to the American Heart Association. The conditions are also caused by two different things: either a problem with the electrical signals to the heart in the case of cardiac arrest or a problem with blood circulation in the case of a heart attack.
Cardiac arrest is a condition that triggers without warning and happens when the electrical signals to the heart become interrupted, causing a condition known as arrhythmia, or an irregular heartbeat, explains the American Heart Association. When the heart's pumping action stops, blood cannot reach organs such as the brain and lungs, and within a few seconds, the person usually loses consciousness and has no pulse. Without immediate emergency medical attention, death can result within minutes.
A heart attack occurs when an artery becomes clogged, preventing the flow of oxygen-rich blood to the heart, states the American Heart Association. If the artery is not unclogged quickly enough, the cells in the blocked area begin to die. Symptoms can appear suddenly, but in most cases, they develop during a period of days, weeks or months. The heart also continues to beat during a heart attack.