Standard Manual Defibrillators (SMD)
Standard manual defibrillators are used in hospitals and ambulances by medical professionals. These units require medical knowledge and diagnostic skill because the person delivering the shocks has to determine if the heart is in V-Fib. The standard manual defibrillator delivers shocks through two charged paddles. A medical professional places one paddle just to the right of and above the heart, and the other under the left axillary area, to deliver shocks. She also has to determine when to shock the heart, how much voltage to use and how often to shock it.
Automated External Defibrillators (AED)
Automated external defibrillators are often found in public places, like restaurants, and are also available for home use. With automated external defibrillators, a lay person places sticky pads on either side of the heart, slightly right of the center of the chest and just beneath the left axillary area. The sticky pads have electrodes and sensors that read the heart rhythm. The machine determines when to shock, how often to shock and how much voltage to use. All the lay person needs to do is follow the directions for placing the pads, read the screen prompts and press the button when directed. An AED will not deliver a shock on a stopped heart or a heart that has a rhythm it cannot recognize.
Implantable Cardioverter Defibrillators ((ICD)
With implantable cardioverter defibrillators, a medical team implants electrodes into the heart. The electrodes are connected to a battery box in the abdomen and detect abnormal heart rhythms. If the electrodes detect fibrillation or other arrhythmias, the box delivers a shock to restore normal heart rhythm. An ICD is similar to a pacemaker; the difference is that the pacemaker actually takes the place of the body’s biological pacemaker and maintains a regular heart rhythm. With an ICD, the body still uses its own pacemaker and the ICD send shocks if the heart rhythm becomes abnormal.