Defibrillators were first used in 1899 and have since evolved into life-saving machines. A defibrillator revives the heart and stops the arrhythmia, ( an abnormal rate of muscle contractions of the heart). Defibrillators also depolarize what’s known as a critical mass of the heart muscles. They also allow the sinus rhythm to be reestablished and return the heart to a normal pace. Defibrillators administer electric shocks to the heart, either internally or externally, and some diagnose the heart rhythm itself. These are mostly used in cardiopulmonary resuscitation and for a heart attack.
There are several types of defibrillators. Some are used by medical professionals, while others are designed for those with little to no medical knowledge. A manual external defibrillator is designed for those with detailed medical knowledge, and they are often found in hospitals and ambulances. These are used with or already have electrocardiogram readers, which are used to diagnose the patient’s cardiac condition. A manual internal defibrillator is used directly on the heart and they are used in surgical operating theatres.
A semi-automatic defibrillator is mainly used by paramedics and EMTs or emergency medical technicians. They are practically the same as an automated external defibrillator except they include an ECG screen and a manual override. Another type is the implantable cardioverter-defibrillator, or ICD. These are extremely similar to pacemakers. They read and monitor heart rhythms and shock if necessary. Some include a ring magnet so users can disable it if it’s shocking constantly or inappropriately. The wearable cardiac defibrillator is just like the ICD except that it is worn like a vest.
Automated external defibrillators, or AEDs, are used for emergencies where there is no likelihood of a nearby person having extensive medical knowledge. AEDs are found in public places with high-risk persons. For example, a community center for teenagers is low-risk because they are young and fit. They are not at a higher risk for heart attack or other related heart problems. An office building or senior citizens home are high-risk places because the people there are older. They are also found in government offices, fitness centers, airports, schools, restaurants, shopping centers, sports stadiums, hotels, and community centers. High-rise office buildings may have AEDs in the elevator. They are brightly colored and mounted in protective places near an entrance. When opened, the case sounds a buzzer or alarm to alert nearby staff, but the sound will not summon or alert emergency services. Ambulances often carry AEDs along with a manual external defibrillator.
AEDs are ideal for public use. They are portable and can treat two common types of arrhythmias: pulseless ventricular tachycardia and ventricular fibrillation. Ventricular tachycardia is a condition in which the heart is pumping too fast for blood to circulate. Ventricular fibrillation is the condition in which chaotic electrical activity stops the heart from pumping blood effectively. An AED usually takes 10 to 20 seconds to determine the heart rhythm. AED use is taught in numerous courses such as first aid, first responder, and basic life support CPR classes. Without AEDs many incidents of cardiac arrest could lead to extensive brain damage or death. During cardiac arrest, blood stops flowing to the brain. Irreversible brain damage may begin to occur after 3 to 5 minutes of cardiac arrest and every minute a person is in cardiac arrest, the chances for survival decrease by 10 percent.
An AED case contains a face shield for rescue breathing to protect the first aider, nitrile rubber gloves, trauma shears for removing clothing, a towel to remove moisture, and a razor to remove hair for those with hairy chests.