In some people, cardiomyopathy may develop in the absence of ischemic heart disease. People whose ejection fractions (the amount of blood pumped out of the heart with each heartbeat) is less than 30% are at greater risk for sudden death (a normal ejection fraction is above 50%). Often it is ischemic, where part of the heart muscle doesn't get an adequate blood supply for a prolonged period and no longer can efficiently pump blood. Cardiomyopathyis a broad category of heart disease where the heart muscle does not contract properly for whatever reason.

Congestive heart failure and heart valve problems, like aortic stenosis (narrowing of the aortic valve), also increase the risk of sudden cardiac arrest.Sudden death may also be the first sign or symptom of heart disease. The reason many people with chest pain are admitted to the hospital is to monitor their heart rate and rhythm for signs that might lead to ventricular fibrillation. In a heart attack ( acute myocardial infarction), a blood vessel becomes completely blocked by a blood clot, and there is enough irritability of the muscle to cause ventricular fibrillation. When blood vessels narrow, the heart muscle can become irritated because of a lack of blood supply. Sudden death is most often caused by heart disease. What are the causes of sudden cardiac arrest? The absence of a heartbeat is known as asystole (asystole: a=no + systole=beat). Less commonly, the heart can just stop beating. Automatic external defibrillators (AEDs) are commonly available in public places to allow almost anybody to treat sudden death. Ventricular Fibrillation is treated with electrical shock, but for it to be effective, the shock usually needs to happen within less than four to six minutes, not only for it to be effective, but also to minimize brain damage from lack of blood and oxygen supply. Without a coordinated electrical signal, the bottom chambers of the heart (ventricles) stop beating and instead, jiggle like Jell-O. Ventricular fibrillation (V-Fib) is the most common reason for sudden death in patients. The heart muscle can't supply blood to the body, particularly the brain, and the body dies. This mechanism can break down in a variety of ways, but the final pathway in sudden death is the same: the electrical system is irritated and fails to produce electrical activity that causes the heart to beat. This pumps blood through the heart valves and into all the organs of the body so that they can do their work. This electrical spark is carried through pathways in the heart so that all the muscle cells contract at once and produce a heartbeat.

The heart is an electrical pump, where the electricity is generated in special pacemaker cells in the upper chamber, or atrium, of the heart. Sudden cardiac arrest is the result of an electrical malfunction of the heart.

3 minutes before death