<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
What causes someone to have a heart attack?
<|assistant|>
Heart attacks are caused by a blockage in an artery supplying blood to the heart muscle. This blockage is often the result of atherosclerosis, a buildup of fatty material on the artery walls. When the artery is blocked completely, the heart can't get enough oxygen and blood, and it can't pump properly. This can lead to chest pain, heart damage, or death if it isn't treated quickly.