My regular readers are a sharp bunch, so you probably already know that cardiac arrest – the cessation of a pulse and of blood circulation – is very very bad for you.  Most doctors don’t recommend it.  Nevertheless, hundreds of thousands in the U.S. every year suffer cardiac arrest outside of a hospital, frequently due to a heart attack.  Cardiopulmonary resuscitation (CPR) was developed 50 years ago for just such situations.  Decades of data strongly support that the following two factors are k...