Cardiac arrest and a heart attack are not the same thing. A heart attack occurs when blood flow is reduced or lost due to a blocked coronary artery.
Person is generally conscious and in discomfort
Blood flow, and therefore oxygen delivery, is blocked or minimized
Signs can include: pale colour, profuse sweating, chest pain, nausea and/or vomiting, shortness of breath.
While they are not the same thing, a heart attack can lead to cardiac arrest if it is not quickly treated. This is why both are serious medical emergencies and 9-1-1 should be activated as soon as possible.