Imagine you are sitting one night at home watching television. One of your favorite characters develops chest pain and passes out. In the next moments, an ambulance arrives and paddles are put on your character’s chest and he is “shocked” by a defibrillator. The television character wakes up and is saved.
How much of this is based on reality and how much is make-believe? In the real world, it is quite possible that the person’s heart went into an irregular heart rhythm, called ventricular tachycardia, and the shock was able to fix it - in fact, it might be the difference between life and death.
There are two broad categories of defibrillators. The first is the type that is implanted into a person, known as an implantable cardio defibrillator (ICD).
The other is the external type which requires bystander help. An example of the external defibrillator is the automatic external defibrillators (AED), which many airports, schools, and buildings are beginning to own.
When a person is unconscious, a bystander takes the defibrillator out of the box, attaches two stickers to the victim (the locations for these stickers is outlined on the box) and presses a button telling the machine that you are ready for it to analyze the patient’s heart rhythm. The machine will then tell you (with a computer voice) if you should press the “shock” button. Research studies have shown that using this machine can save lives! It is that simple!
What is the benefit of being shocked?
Normally, a person’s heartbeat starts at the top part of the heart (atrium) followed by stimulation of the bottom of the heart (ventricle). In certain situations, the bottom part of the heart (the ventricle) can start beating very fast and independently of the rest of the heart. This is called ventricular tachycardia (or, in its more advanced stage, ventricular fibrillation). When the ventricle beats very fast, the heart does not have enough time to circulate blood and the person can pass out or even die.
This abnormal heart rhythm can occur at the time of a heart attack, but can also be seen in other people, especially those with weak heart muscles. By using the defibrillator, the dangerous rhythm can often be jolted into a normal rhythm once again.
Now, is there anything that can be done to avoid reaching this point?
As was just mentioned, people with decreased heart function are at increased risk of developing this rhythm. In fact, we know that people with very depressed heart function often benefit from having a defibrillator implanted before a crisis occurs.
Defibrillators are inserted during a minor surgical procedure. A small incision is made underneath the skin and a wire is put in a blood vessel leading back to the heart. The actual defibrillator is placed underneath the skin. All defibrillators have a pacemaker as part of them as well. This implantable defibrillator is able to tell when the heart goes into a dangerous irregular heart rhythm and automatically delivers a shock to correct it.
Lawrence Phillips, M.D. is a second year Cardiology fellow at Long Island Jewish Medical Center and North Shore University Hospital. The statements presented here are for information only and do not replace speaking to your own physician.
