10/15/2026
Sudden cardiac arrest (SCA) and heart attacks are often confused but are actually very different things. SCA is known as an electrical issue within the heart which is a heart rhythm issue. Someone experiencing SCA is not conscious or responsive, this requires CPR.
On the other hand, myocardial infarction, also known as a heart attack is a plumbing issue. This means there's a blockage somewhere that is not allowing blood to flow how it should (or at all) to the heart. This is still something that requires medical attention, but you will not need to perform CPR or use an AED on this person.
Source: American College of Cardiology
https://www.cardiosmart.org/topics/sudden-cardiac-arrest
https://www.cardiosmart.org/topics/heart-attack