Question

Does a heart attack always leave scar tissue on the heart?

Answer 1

A heart attack leaves a scar in the cardiac tissue called an infarct.

Explanation:

Cardiac muscle needs oxygen to contract - even depriving it of blood flow (hence oxygen) for a few minutes will irretrievably damage heart muscle.

When one of the various coronary arteries that supply the heart with blood gets blocked (i.e., most common cause of heart attacks) and that particular part of the heart does not get oxygen it dies. It leaves a scar that is mostly fiberous tissue and, depending on its size and where in the heart it is located, can make it very difficult for the heart to continue beating normally.