Would it be possible that a heart attack really cause permanent brain damage. if so, how?

Secondary: A heart attack is heart damage. But if the heart attack causes low blood pressure, shock, hypoxia, cardiac arrest etc. Then brain damage can occur. Atrial fibrillation, clotting and embolism to the brain can cause strokes as well.

Sometimes.: If the heart attack results in an inability to pump blood to the brain at a sufficient pressure and flow to to keep brain cells alive, this can result in the death of these brain cells. A heart attack can do this if the heart muscle is not strong enough to pump the blood, or if is associated with an abnormal heart rhythm that decreases the ability of the heart to pump.