View full lesson: http://ed.ted.com/lessons/what-happens-during-a-heart-attack-krishna-sudhir Approximately seven million people around the world die from heart attacks every year. And cardiovascular disease, which causes heart attacks and other problems like strokes, is the world’s leading killer. So what causes a heart attack? Krishna Sudhir examines the leading causes and treatments of this deadly disease. Lesson by Krishna Sudhir, animation by Chadwick Whitehead.