Coronary arteries are the blood vessels we try to keep clear through healthy eating. Blocked coronary arteries result in a heart attack.
The heart, like any organ, requires blood for oxygen and other nutrients so it can do its work. The heart does not gather oxygen or nutrients from the blood flowing inside it. Instead, it receives blood from coronary arteries that eventually carry blood into the heart muscle. Approximately 4 - 5 percent of the heart's blood output goes to the coronary arteries.
The heart also has veins to collect oxygen-poor blood from the heart muscle. Most major veins of the heart drain into the coronary sinus. The sinus opens into the right atrium.
A blockage in one of the coronary arteries causes coronary artery disease. When a coronary artery is partially blocked, it cannot supply enough blood to the heart muscle. The muscle needs this blood to meet its needs during exertion. If someone with coronary artery disease exerts himself, it causes chest pain. This is from lack of blood and oxygen to part of the heart muscle. The pain is called angina. If the obstruction worsens, a condition called unstable angina can occur. When a coronary artery is completely blocked, meaning no blood or oxygen is getting to the heart muscle, a heart attack occurs. This also causes chest pain and death to the heart muscle served by the blocked artery.