Not common. Unfortunately, uncommon. Hard to say exactly, & depends somewhat on what kind of cardiac arrest, what other problems the person has, how long before care, etc. Generally though, for out-of-hospital arrests, less than 20% survive long enough to be discharged from the hospital. Also concerning is how often cardiac arrest is the 1st sign of underlying CAD (plaque in vessels). See a proactive doctor!
Depends. The probability of surviving cardiac arrest also depends on the availability of an aed(portable defibrillator) and the laws in your state pertaining to the use of aed's. The city of seattle has a 25% survival rate compared to the national average of around 5% survival due to readily available devices and user friendly laws.