Stroke is a disease that affects the arteries leading to and within the brain. A heart attack occurs when blood flow to a part of the heart is blocked, usually by a blood clot. Without oxygenated blood, the heart muscle begins to die. A stroke is a brain attack, cutting off vital blood flow and oxygen to the brain. Early treatment with medication like tPA (clot buster) can minimise brain damage. Other treatments focus on limiting complications and preventing additional strokes.