AED A Shocking Lifesaver in Sudden Cardiac Arrest

Sudden Cardiac Arrest (SCA) is a serious life threatening condition wherein the heart beat stops all of a sudden due to varying causes. This causes reduced blood supply to the brain and other organs causing oxygen deprivation and death. SCA is cause for more than 350,000 deaths in the United States alone. The average number of people who experience sudden cardiac arrest in America is as high as 500,000 every year.

To help reduce the mortality from SCA, we should first understand more about the killer condition and some measures that need to be taken to prevent sudden cardiac arrest and emergency treatment required to help reduce the mortality rate from the condition.

Sudden Cardiac Arrest is often confused with heart attack although they are different. Many people even refer to the condition as a sudden and severe heart attack although this terminology is not correct.

While heart attack is caused due to reduced blood supply to the heart musculature, SCA is caused due to improper electrical impulses. Electrical activity controls the beating of the heart and regulates the number of beats and rhythm. When there is a disturbance to this electrical activity in the heart, it causes abnormal beating of the heart and a disturbance of rhythm known as arrhythmias.

Arrhythmias are of different types and cause disturbances in the heart beat making it either go slow or make it irregular. There is also a condition where the heartbeat increases and this is known as tachycardia. However, all arrhythmias will not cause SCA. SCA is more often caused by Ventricular arrhythmia, a condition where in the left ventricle of the heart is unable to supply blood to the various parts of the body.

There are many contributing factors for a person to develop SCA. Understanding these factors will help in knowing who carries a higher risk of suffering sudden cardiac arrest. Some of these contributing factors that can predispose a person to SCA include the following:

Familial History of CAD (Coronary Artery Disease) - Coronary Artery Disease is caused due to blockage of coronary arteries by plaque (usually caused due to high levels of bad cholesterol). The coronary arteries supply blood to the heart musculature and reduced blood supply can cause loss of function of the area of the heart that these arteries supply causing a heart attack.

Although a heart attack is not the same as SCA, a person is at high risk of sudden cardiac arrest following a heart attack. Following a heart attack, there is the formation of scar tissue in the areas of the heart that receive lesser blood supply. This scar tissue can cause disruption of the electrical impulses traveling within the heart thereby rising the chances of arrhythmias and sudden cardiac arrest.

Familial History of SCA and Arrhythmias – The risk of SCA is higher in people whose family history has many people who have previously suffered from SCA and arrhythmias. There are many electrophysiological abnormalities of the heart like Brugada Syndrome, long QT syndrome (LQTS), etc which causes abnormalities in the electrical activity in the heart thereby increasing the risk of SCA.

Congenital Disease of the Heart – Although the occurrence of SCA in infants and children is quite less, some congenital conditions of the heart (heart problems at birth) can increase the chances of SCA.

Cardiomyopathy – This is a condition wherein there is an enlargement of the heart due to thickening of the heart musculature. There are many more such conditions that can cause changes to the structure of the heart or its size. These conditions can predispose to high occurrence of SCA as it causes disturbances to the electrical activity in the heart.

Apart from these contributing factors, there are many risk factors that increase the chances of a person suffering from Sudden Cardiac Arrest. Some of these risk factors include the following:

• High stress levels
• Sedentary lifestyle
• Habits like smoking, excessive alcohol intake and drug abuse.
• Hypertension and increased levels of bad cholesterol in the blood.
• Excessive body weight
• Diabetes
• Previous Episodes of SCA, heart attack or other heart conditions.

Now that we have understood the predisposing and risk factors associated with SCA, let us next understand what happens when a person suffers from sudden cardiac arrest.

The normal pumping of the heart is activated by the electrical impulses that initiate from the brain and then continue due to succeeding impulses that are regulated on the surface of the heart. When there is a disturbance to these impulses, it causes irregular activity thereby causing the heart to lose its rhythm and thus resulting in improper blood supply to all the areas of the body, including the brain.

As blood carries oxygen to various parts of the body, reduced blood supply causes oxygen starvation and increase in carbon dioxide in the body. This kind of a situation is toxic and causes loss of function. When vital organs fail to function, it can result in death in a very short span of time.

The most common symptoms of SCA include cessation of breathing, reduced level of consciousness and absence of a pulse or heartbeat.

The worst part of SCA is that it cannot be diagnosed prior to its occurrence and once it occurs, emergency procedures need to be carried out and then diagnostic tests performed to eliminate other causes leading to similar symptoms thus establishing a final diagnosis.

Time is of huge importance in SCA. The more the time that has elapsed the lesser is the chance of survival of a person who has suffered from the condition. Also, the chances of recovery of brain function also goes down as more time elapses following the onset of SCA.

Emergency medical procedures need to be initiated as quickly as possible for improving the chances of recovery and reducing the possibility of fatality. The emergency procedures that need to be initiated include the use of a defibrillator to correct the irregular rhythm of the heart and CPR (cardiopulmonary resuscitation) to make the heart beat.

As time is of essence, it is better if revival of the person can begin before emergency medical services can arrive. This is where AED (Automated External Defibrillators) can help.

Previously, defibrillators were present only in hospital settings and operated by qualified personnel. But, these could not be of timely help for many people who suffered from SCA. But, as technology improved, AEDs began to arrive on the scene and now defibrillation can be undertaken even by a novice just by following step-by-step instructions.

The advantage of an AED is that it will provide defibrillation when necessary and will not provide the electrical shock if the condition does not warrant it. So, a novice does not have to determine whether the person is actually suffering from SCA while applying the device to the heart. Also, many models come with providing the person help in the right way to administer CPR which is also of essence when it comes to emergency treatment of SCA.

For this reason, AED devices are now finding a place in many a public place like malls, stations, airports, offices, schools, etc so that timely help can be immediately administered before emergency services become available. This has helped save many lives which would not be possible earlier.

But, in many cases, SCA is known to occur in the confines of the person’s own home. For this reason, many people, especially those who are at high risk of SCA, are now opting to purchase AED devices and training themselves and their family members to use an AED in case of an emergency.

Although emergency service personnel try to reach as quickly as possible, it is not timely for many a person suffering from SCA. AED devices have come as a huge boon to saving lives and augmenting the efforts of medical and emergency personnel in trying to reduce mortality from this killer condition.