Sudden cardiac arrest is not a heart attack, or myocardial infarction, but it is possible to occur during a heart attack. A heart attack is a blockage of arteries to the heart, therefore stopping the heart from getting enough blood with sufficient oxygen in it. Sudden cardiac arrest happens when the electrical system to the heart fails and becomes irregular; the heart begins to beat too fast and the ventricles quiver or flutter, which is called ventricular fibrillation. During this process blood is not delivered to the body, causing the person to lose consciousness due to the blood flow to the brain being so drastically reduced, and death is close unless the necessary treatment is administered immediately.
Treatments include cardiopulmonary resuscitation, CPR, and defibrillation; CPR being a manual technique by pressing into the chest and breathing into the person's mouth repeatedly to keep oxygen-rich blood flowing, and defibrillation is an electric shock to the chest. People sometimes experience a racing heartbeat or they will feel dizzy before the cardiac arrest begins, but mostly sudden cardiac arrest happens suddenly without any symptoms beforehand. When SCD occurs, it is mainly because of arrhythmias, or abnormal heart rhythms, which the most common is ventricular fibrillation; if left untreated, the heart will be unable to pump blood and death will come in a few minutes. Previous heart attacks, coronary artery disease, prior episode of sudden cardiac arrest, family history of sudden cardiac arrest or SCD, ventricular tachycardia or