W8
can I just throw in what may be a red herring.
a cardiac (heart) arrest (stoppage) isnt caused by "failure" of the heart. it is caused by a blood clot obstructing the blood supply and leading to death of the muscle tissue through oxygen starvation.
Not a bad stab at correction but what you have actually described is what is commonly known as a heart attack or Myocardial (heart muscle) Infarction (death) or MI in this case due to O2 starvation. Ultimately, if large enough or sudden enough and not treated this will lead to disruption of the normal sinus rhythm NSR and ventricular fibrillation VF at which point the patient is now actually suffering a cardiac arrest.
Treatment now requires an AED to stop the heart totally and try and allow the sinus rhythm to reset.