Substances that dilate blood vessels. Coronary vasodilators, such as NITRATES, CALCIUMCHANNEL BLOCKERS and POTASSIUM-CHANNEL ACTIVATORS, are used in heart failure to improve blood supply to the heart. Peripheral vasodilators affect the blood vessels in the limbs and are used to treat conditions due to poor circulation such as CHILBLAIN and RAYNAUD’S DISEASE.... vasodilators