Today, SCA has become such a common event that, one looses ones security in life. You are not sure whether tomorrow would be a reality. And when it happens to your close relation or your colleague or your fellow neighbor, you are totally devastated. We often wonder how helpless we are. With all the facilities in the world, we are not able to prevent this entity that leads to Brain death. But, I am sure, with a bit of awareness among the lay public we would be able to bring about a world of difference in saving these unfortunate victims from the clutches of death.

Only around 30 percent of SCA can be conclusively attributed to the occurrence of an Acute Myocardial Infarction (Heart Attack). Studies have shown that in many instances a normal cardiac rhythm can be achieved by the prompt application of an electric shock to the arrested heart.

Between 50 and 80 percent of SCAs occur at home; often without warning or witnesses, thus making the use of a traditional external defibrillator manned by trained personnel an occurrence that is seldom an option. The lack of on the spot trained personnel and needed equipment makes the victim's chance for survival before reaching a hospital less than one in 20. Although the average age of an SCA victim is around 65, younger people in there 30s and 40s are not immune. While it is generally misconceived that cardiac arrest occurs only in adult males, the ratio of male to female victims is relatively equal. Early defibrillation is without question the single most important therapy for the treatment of adults in VF. For each minute the arrhythmia persists, the likelihood of successful resuscitation decreases by 10 percent. After 10 minutes there is very little chance that resuscitation will succeed. The survival rate increases by as much as 30 percent when early CPR and early defibrillation were provided. This compares to a national survival rate of 5 percent or less.

Sudden death at any age is a tragedy. When the victim is a child, the tragedy is compounded, with many years of life lost and dreams unfulfilled. As many as 7000 children die from cardiac arrest (SCA), each year.

The use of on-site Automated External Defibrillators (AED) to treat cardiac arrest is rising in the West, because traditional emergency medical service (EMS) is unavoidably too slow. The single most important determinant of survival is the time from collapse to defibrillation. Most patients will survive if defibrillation is achieved in less than 3 minutes; few will if the delay is 16 minutes or longer, despite CPR administration.

The chances of survival following cardiac arrest are considerably improved if appropriate steps are taken to deal with the emergency. These steps are

• Recognition of cardiac arrest
• Early activation of appropriate emergency services
• Early basic life support
• Early defibrillation
• Early advanced life support

 Facts and Statistics

 Sudden Cardiac Arrest

The vast majority of cardiac arrest cases occur, of course, in non-athletes. The American Heart Association (AHA) estimates that about 350,000 people die of cardiac arrest each year. The AHA estimates that 100,000 deaths could be prevented each year with rapid defibrillation. Each day more than 700 Americans die of sudden cardiac Arrest. About 95 percent of sudden cardiac arrest victims die before reaching the hospital.    

The cause of death in athletes is usually ventricular fibrillation associated with underlying cardiovascular disease or as a result of blunt impact to the chest wall (commotio cordis) as in the case of footballer - Christiano Junior at Bangalore-2004.

VF usually results from cardiovascular disease but may also result from electrocution or near drowning.

Cardiopulmonary Resuscitation

• About 74 to 80 percent of all sudden cardiac arrests happen at home; so being trained in cardiopulmonary resuscitation (CPR) can mean the difference between life and death for a member of your family.
• Effective bystander CPR, provided immediately after sudden cardiac arrest, can double victims chance of survival..
• The survival rates for performing basic cardiopulmonary resuscitation (CPR) alone are reported between 0% and 6%. Theoretically, even more lives could be saved if targeted members of the general public could obtain early access to and have training in the use of AEDs and CPR.

Defibrillation and Automated External Defibrillators (AEDs)

Manual defibrillation has been widely available for many years, but the requirement for training in arrhythmia recognition, limits the application of this technique to medical practitioners, nurses working in critical care areas and ambulance paramedics.

Recent developments in automated external defibrillators (AEDs) have enabled increasing numbers of individuals to perform defibrillation safely and effectively. Such individuals (designated first responders) include ambulance technicians, general ward nurses, members of first aid and rescue organizations, police officers, fire fighters, airline cabin crew, security personnel and specially trained members of the public.

The AED is a safe and effective device and is nearly 100% accurate in the detection of ventricular fibrillation and the detection of a nonshockable rhythm. AED technology evolved from the experiences gained with portable and implantable defibrillators. The AED is built with an electronic microprocessor (the brain of the device), which controls the analysis and defibrillation functions. Through electrodes placed on the patient's chest, the AED senses and analyzes the cardiac rhythm of the heart and makes a decision based upon that information. If defibrillation is indicated, the unit will alert the operator that a shock is needed. During this time, lithium batteries charge a capacitor to a preset level and the unit waits for the command by the operator to shock.

The amount of energy delivered to the heart is measured in joules. The maximum delivered amount can be 360 joules. If shock is initiated, the electrical energy is sent through the electrodes, into the chest cavity and the heart receives an electrical pulse. A repeat analysis is performed by the device to determine if another shock using higher energy content (joules) is required. This sequence is followed until a nonshockable rhythm is attained or life support efforts are ended.

AED with pads

Adhesive pads are attached to the defibrillator cables (some units contain prepackaged, already attached cables and pads). Once the cables and pads are joined and connected to the unit, the rescuer attaches them to the patient's chest. The leads are placed on the upper-right sternal border and lower-left ribs over the heart. After pad attachment, CPR is stopped and the unit does an analysis. All contact with the patient during analysis must be avoided in order to obtain accurate readings. Depending upon the brand of device, assessment can take from five to fifteen seconds. The device will notify the responder that shock is indicated using a written message, visual display, or more commonly, a synthesized or recorded voice. If the patient needs to be shocked, the responder should announce, "Clear the patient," "I'm clear," or some other notification that the patient is to be shocked. The shock control is then initiated and shocking completed.
CPR can be restarted after the device performs a second analysis. This sequence of analysis, notification, shock, and CPR is continued until up to three shock cycles have been completed. Between cycles, CPR should be resumed for 60 seconds. Repeated shocking can go on until Advanced Life Support (ALS) arrives.

Remember that patients must be medically unstable or pulse less before AED is applied. They should be pulseless before assessing the rhythm. This becomes increasingly important as more laypersons are given the opportunity to use AEDs.

In order to prevent accidental shocking, the unit should not be used to analyze the rhythm while CPR is performed. Most new units have incorporated a motion or CPR detector. Also AEDs should not be used if the patient is seizing, and should be used only with caution in a moving vehicle. If it must be used on a patient in transport, frequent stops for pulse and AED monitoring checks should be made. Most units are now designed to warn when motion or poor contact is detected. But it is important to recognize that if wet, it should be dried off. Water spots or nicks in the skin result in areas of decreased electrical resistance and could lead to local burns as well as uneven and ineffective defibrillation. Electrodes should not be placed directly over an implanted pacemaker or internal defibrillator device.

The most widely known alternative treatment to AED devices for VF is CPR. CPR is the first method used, but should not be used exclusively when other tools such as AEDs or Advanced Cardiac Life Support measures are available. CPR is considered life sustaining (keeps victims alive until effective treatment can be given) and not necessarily life saving (victim's breathing and heart functions continue without assistance after treatment) when used for sudden cardiac arrest victims. CPR should be considered only as an interim measure, which gives the victim life support until defibrillation can take place.

The earlier the response to a cardiac arrest, the higher the chance of survival. In hospital studies where cardiac arrest is witnessed and early defibrillation is a method of treatment, survival rates as high as 89 percent have been reported. Several studies have reported improved survival rates for SCAs occurring outside the hospital when early defibrillation was used.

Should AEDs be available on airplanes and in other public places?

Yes. Since seconds count when a person experiences a heart attack, Logical places for AEDs include Police Cars, Theaters, Schools, Colleges, Sports arenas, Public buildings and Auditoriums, Business offices, Railway stations and Airports. An increasing number of commercial airplanes are now equipped with AEDs and enhanced medical kits.

Do AEDs replace the use of CPR?

No. When a person experiences cardiac arrest, CPR will help keep oxygen flowing to the brain, but the electric shock of an AED vastly improves the chances of restarting the heart. AEDs can be used as part of cardiopulmonary resuscitation. CPR is still needed, starting with determining whether a person is unconscious, breathless, or pulseless.

What's the difference between an AED and the defibrillators used in hospitals?

In-hospital defibrillators are manual, larger than AEDs, and designed to be used only by qualified medical personnel with special training to use the device and to recognize heart rhythms. Medical personnel who use the device must decide whether or not to shock the person. Manual defibrillators also have additional capabilities such as pacing and cardioversion.

AEDs are programmed to recognize different heart rhythms and to make the shock/no shock decision, so that users don't have to. They were designed so that lifesaving defibrillation could be performed as quickly as possible.

Weve all seen heartbreaking headlines:

• A ball strikes a 14-year-old player, in the chest, sending his heart into a deadly irregular rhythm. Although he receives CPR and a hospital is less than a mile away, it takes 12 minutes for the boy to receive defibrillation. He dies.
• A 14-year-old student athlete, nicknamed iron man, is running in gym class when he suffers sudden cardiac arrest. More than 10 minutes pass before the first defibrillation shock. He survives with severe brain injury.
• After being cleared with a basic physical, a star football player suffers SCA during football practice. A defibrillator arrives too late to save him. An autopsy discovers an undiagnosed heart condition.

It does not have to be this way. Equipping schools with automated external defibrillators and teaching school nurses, athletic trainers, coaches and others to use them can give anyone struck down by SCA another chance of life.

As you can see, it could be a matter of life and death to have AEDs within easy reach of coaches, school nurses, school administrators, custodial staff and students who are trained to use them. Every minute counts. Typically, only 5 to 10 percent of people struck down by SCA survive. But if people in VF get the lifesaving AED shock within 3 minutes of collapsing, the survival rate can increase to 74 percent. Reducing response time by even 1 or 2 minutes from collapse to shock can mean the difference between death and survival. 

Because early defibrillation is becoming the standard of care in many communities, the public will increasingly expect to find AEDs included in a schools disaster-response supplies.  

CAUSES OF SCA IN YOUTHS

 Although rare, sudden cardiac death does not strike children and teenagers, often without any prior symptoms. Causes include:

 Undetected heart conditions

• Hypertrophic cardiomyopathy, abnormalities in muscle fibers that make the heart muscle thicken, usually caused by an inherited disorder 
• Arrhythmogenic right ventricular dysplasia (ARVD), damaged muscle in the lower right chamber of the heart, which makes the heart more susceptible to abnormal heart rhythms
• Congenital coronary artery defects (defects of the hearts own blood vessels)  
  Undiagnosed heart disease
• Long QT syndrome, an inherited disorder affecting the hearts electrical system, which can lead to life threatening, changes in the heart rhythm.
• Wolf-Parkinson-white syndrome, an electrical malfunction of the heart in which the electrical signals reaches the hearts lower chambers (ventricles) too soon, disturbing the healthy beating of the heart.
• Primary ventricular tachycardia, an extremely fast abnormal heart rhythm that affects pumping function of the heart.
• Primary pulmonary hypertension, increased resistance to blood flow through the lungs, leading to abnormally high blood pressure in the arteries that supply blood to the lungs.

Previously diagnosed heart conditions

• Dilated cardiomyopathy, abnormal heart muscle causing the walls of the heart to stretch under pressure, weakening the hearts pumping capacity.
• Marfan syndrome, an inherited disorder of the connective tissue, often resulting in abnormalities in the heart or aorta, the main blood vessel leading away from the heart 

Accidents and risky behaviors

• Commotio cordis, caused by a blunt blow to the chest at a critical time in the cardiac cycle, which can cause a deadly irregular heartbeat
• Cocaine or other stimulant abuse
• Electrolyte imbalances caused by eating disorders, rapid weight loss or dehydration.