defibrillation

Use of electrical stimulation to restore a chaotic heartbeat to a rhythmical pattern. In fibrillation, which may occur in most kinds of heart disease, the heart muscle contracts irregularly; the heart is no longer working as an efficient pump. Paddles are applied to the chest wall, and one or more electric shocks are delivered to normalize the beat.

In patients suffering with arrhythmia, implantable defibrillators are inserted into the chest with leads threading through veins into the right side of the heart. The first was implanted in 1980 and by 1999 around 400,000 had been implanted worldwide.