It can occur in a person with or without heart disease. This happens due to an abrupt disturbance in the heart’s rhythm which results in the heart not beating or beating too little to keep the person alive.
The rhythm disturbances are of different types.
In each case, it occurs suddenly or very shortly after the onset of symptoms. Without treatment, the outcome is usually fatal.
The heart has an inbuilt electrical system, which makes it work. When this is interrupted, the heart cannot pump enough blood around the body and sudden cardiac death results.
Without a supply of blood pumped by the heart the brain can’t function, the victim faints and death follows within minutes without treatment.
Usually, there are no early warning signs. Within seconds the person collapses, is not breathing or may be only gasping. This can occur in a person with or without heart disease and may occur after a heart attack.
The problem occurs due to an abrupt or sudden disturbance in the heart’s rhythm which results in the heart not beating or beating too little to keep a person alive. This life threatening arrhythmia or abnormal heart rhythm is called ventricular fibrillation (VF).
You can do a lot to prevent heart disease (coronary heart disease) and reduce your risk of having a heart attack. As this is the most common cause of sudden cardiac arrest it is the best way of preventing an adverse event.
If you have heart disease or any condition which increases your risk, you will likely need to take medications and carefully manage your condition to help to reduce your risks.
For some people with a known high risk – like heart attack or an inherited arrhythmia (e.g. LQTS) – your doctor may prescribe medications to steady your heart rhythm or recommend an implantable cardioverter defibrillator (ICD).
With cardiac arrest a person collapses suddenly, has no pulse, is not breathing and is unresponsive.
If treated quickly with an electric shock, delivered by an automated external defibrillator (AED), normal heart rhythm can often be restored. In addition, the best chance of survival is someone nearby knowing how to do CPR (the survival rate decreases by 10% for every minute nothing is done).
If CPR and defibrillation are delivered early on, there is a good chance of successfully resuscitating the person. There are some instances when these life-saving measures are delivered too late and although the heart returns to its normal rhythm, the brain may be severely damaged.
In individuals who have been successfully resuscitated it is important to investigate thoroughly and provide the necessary treatment to avoid further episodes of sudden cardiac death. Sometimes the situation is due to a drug overdose and avoidance is all that is necessary.
In the majority of cases, the problem is related to narrowed coronary arteries (heart disease). In this situation, it may be necessary to perform a procedure to either open up the narrowed vessel (angioplasty and stenting) or to bypass the narrowed arteries (coronary artery bypass surgery (CABG)).
In some circumstances, this is not sufficient to prevent the problem or there is another cause of the sudden cardiac death. In these situations, an implantable cardioverter defibrillator is usually inserted.