Heart attack?

I believe that a heart attack means death of cardiac tissue.
I do not think that it has to mean to necrosis due to lack of oxygen, but could be due to other things such as electrical damage.

So an arrythmias attack that nearly kills someone that leads to perminant damage is a form of heart attack but not a 'myocardial infarction'.

What is the odd of surviving one?

Sorry your question doesn't make sense. The standard view is a heart attack is a myocardial infarction. An area of the heart is deprived of blood flow and O2. There are a number of live threatening arrhythmia's, they are not called heart attacks. It could be SVT, Vfib, Afib, etc. That is what they are called.

As far as surviving a heart attack, It depends on where it is and how big and how long and the kind of treatment you receive.

A heart attack (also known as an acute myocardial infarction) is when the blood vessels supplying the heart become clogged...this may result in temporary or permanent damage, depending on how big the clot is, and how long the patient waited until treatment.

If a cardiac arrhythmia caused cardiac damage, it woudn't be called a myocardial infarction unless a MI was the cause of the arrhythmia. You would just have cardiac damage caused by an arrhythmia. I don't know the statistics regarding surviving an arrhythmia...lots of people survive various arrhythmias. There are people walking around every day with some type of cardiac arrhythmia and not experiencing any issues. It's just a matter of what type of arrhythmia it is...with prompt treatment, most are survivable. It's the ones that actually stop the heart (asystole), essentially stop the heart (PEA, V-fib, pulseless V-tach), or make the heart beat so slow or so fast that it can't effectively pump (V-tach, SVT, A-fib with RVR, a really fast A-flutter, a particulary slow bradycardia, the various high degree heart blocks) that can be deadly.

The odds of surviving one are very favorable. Get to an ER within 1 hour after the onset of symptoms. If arteries are blocked, they can be opened up with angioplasty and stents to keep it open.

From there on, it's mostly exercize and diet, and of course cutting out tobacco.