Coronary artery disease (CAD) is a condition that impairs and reduces blood flow through your coronary arteries. These arteries supply blood to the heart muscle. When blood flow to the heart muscle is reduced, the heart isn’t able to do its job as well as it should. This can lead to a variety of complications.

Heart failure

Over time, CAD can lead to heart failure. Heart failure means that your heart isn’t able to pump enough blood to the rest of your body. This can cause fluid buildup in the lungs, difficulty breathing, and swelling of the legs, liver, or abdomen.

Abnormal heartbeat

An abnormal heartbeat is called an arrhythmia. When a person is at rest, the heart normally beats about 60 to 80 times per minute in a predictable, steady rhythm and with consistent force. Arrhythmias that can develop in people with CAD include, but are not limited to, the following:

  • bradycardia, a slow heart rate
  • tachycardia, a fast heart rate
  • atrial fibrillation, a chaotic, irregular rhythm in the top chambers of the heart (atria)

Atrial fibrillation causes your heart to be ineffective at pumping blood out of the atria to the lower chambers of the heart (ventricles) and into other parts of your body for circulation. Over time, atrial fibrillation can lead to an ischemic stroke or heart failure.

Certain types of cardiac arrhythmias, such as ventricular fibrillation, can cause your heart to lose its pumping ability without warning. This kind of cardiac emergency causes sudden death if an external defibrillator device or an implantable cardioverter defibrillator doesn’t restore your heart’s normal rhythm immediately.

Chest pain

Reduced blood flow in your coronary arteries can mean that your heart doesn’t receive enough blood, especially when you exert yourself. This can cause a type of pain called angina. Angina may cause chest numbness or the following sensations in your chest:

  • tightness
  • heaviness
  • pressure
  • aching
  • burning
  • squeezing
  • fullness

Besides your chest, you may feel angina radiating to your:

  • back
  • jaw
  • neck
  • arms
  • shoulders

For example, the discomfort may extend into your right shoulder and arm, down to your fingers, and into your upper abdomen. Anginal pain is typically not felt above the ears or below the belly button.

Heart attack

If the fatty plaque in one of your coronaries arteries ruptures, a blood clot can form. This can greatly block and decrease needed blood flow to your heart, causing a heart attack. The severe lack of oxygenated blood flow can damage your heart. Part of your heart tissue may die.

Sudden death

If coronary artery blood flow to your heart is severely blocked and not restored, it can cause sudden death.

Related arterial diseases

The process that causes injury and plaque to accumulate in the coronary arteries can affect all of the arteries in the body.

The carotid arteries in the neck supply blood to the brain. Atherosclerotic plaques in these arteries can lead to ischemic strokes.

Plaques elsewhere can impede blood flow within the arteries that supply the legs, arms, or other vital organs, and accumulation of these plaques can lead to aneurysm formation with life-threatening rupture, such as an aneurysm and rupture of the abdominal aorta or a cerebral artery.

If you have CAD, the earlier in its course you receive the diagnosis and properly treat it, the better your outcome is likely to be.

For some people, changes in diet and lifestyle will be enough to slow the progression of the disease.

For others, medication or surgical therapy will be necessary.

Follow your doctor’s instructions for treating CAD. Each person is different. Be sure to follow the treatment plan that’s best for you.