SCA is a critical emergency medical condition where the heart physically stops beating or goes into fibrillation. If you suffer a SCA you will die within minutes unless you receive the correct emergency medical treatment.
According to the American Heart Association over 700 people die every single day in the United Stated from this condition. This equates to more than a quarter of a million deaths per year !
Is an SCA the same as a heart attack ?
Absolutely not !
A heart attack occurs when there is a blockage in the arteries as a result of coronary artery disease which prevents the flow of blood to the heart. With Sudden Cardiac Arrest the heart either stops dead, or it goes into a kind of spasm called fibrillation where the normal beating action which enables the heart to pump blood around the body is defeated by the muscular spasm, which effectively renders the heart useless.
What are the causes of Sudden Cardiac Arrest ?
In most instances the reason that the heart suddenly stops beating is because of a certain type of irregular heartbeat (arrhythmia), or quivering of the heart muscle, known as a ventricular fibrillation or V-fib, and like most forms of arrythmia it is usually due to an ‘electrical problem’.
The human heart has four chambers – the left and right atria, and the left and right ventricles. The ventricles are the two lower chambers of the heart. The right ventricle pumps deoxygenated blood to the lungs and the left ventricle pumps oxygenated blood out to the body.
The net result of the heart fibrillation is that very little blood gets pumped around the body, which is why death always follows within minutes, unless the patient receives rapid emergency medical treatment.
Why do some people suffer from SCA ?
There are a number of reasons why you may suffer from a sudden cardiac arrest. These are summarised briefly below :-
Previous heart attack
When a person suffers from a heart attack, some heart tissue dies and forms scar tissue. This can damage the heart’s electrical system, and increase the future risk factor for arrhythmias and SCA.
Severe Physical trauma or stress
This may be due a number of reasons such as :-
* Major blood loss
* Severe lack of oxygen
* Very low blood levels of potassium or magnesium
* Intensive exercise, resulting in high levels of the hormone adrenaline to be released into the body. This may trigger an SCA in people who have other heart related problems.
Genetic or congenital heart disorders
It is possible for heart defects, including arrhythmias to run in families, and be passed from parents to children. These problems may not manifest themslves until later life. Others may be born with congenital defects in their hearts that may increase their chance of having SCA, either in infancy or in later life.
Structural Changes to the makeup of the Heart
Our hearts may alter in size or structure during our lifetime, and this can affect the functioning of it’s electrical system. These changes can include a heart which has been enlarged by high blood pressure, infection, or heart disease.
Other electrical problems that can cause SCA are extreme slowing of the rate of the heart’s electrical signals or when heart muscle stops responding to the electrical signals.
Several research studies are under way to try to understand these possible causes of SCA and to find other causes.