Which muscle never gets tired?

Castra, There are many other reasons for heart failure. Healthy diet may help but not a cure all.

Sophie, Heart attacks are not caused by a " tired" heart. They are caused by a build up of fatty plaques in the coronary arteries that supply the heart with oxygenated blood. This causes heart muscle death. So, eat a healthy diet

Sophie, I am asking the same question.

Then why do we have heart attacks??