What are the things doctors use on TV to restart a patients heart?

Question

The one that shock someone's chest, and the doctor says clear.

Answer 1

  It's a high voltage low current D/C generator that returns the heart from fibrillation to sinus rhythm

Answer 2

It's a defibrillator.

Most of the scenes where it's being shown being used, it's used incorrectly.  Let a medical professional do the work, not an actor.

Answer 3

a defibrilator?

Answer 4

It's called a defibrillator, and it doesn't re-start the heart, it kinda "slaps" it into acting right (sometimes).  There are only 2 cardiac rhythms that can be defibrillated- v-fib (or ventricular fibrillation), and pulseless ventricular tachycardia.  Basically your heart is having a ginormous seizure because the electricity in it is going nuts.  When we attempt to defibrillate someone (and I say "attempt" because it doesn't work sometimes), we're sending an electrical current through the heart, which is supposed to momentarily stop this abnormal activity & allow the heart to "re-set" itself. Basically giving it a slap in order for it to act right.

There are also 2 types of defibrillators- uniphasic, and biphasic.  Uniphasic send the current from one paddle, through the heart, and into the other paddle.  Biphasic send the current from one paddle, through the heart, and bounce it back to the original paddle.  Biphasic is a newer technology, and is what most (if not all) new defibrillators have.  Another difference is that you can obtain the same effect, but with a lower joule setting with the biphasics (effectively damaging less tissue).

Hope this helps!