What Are the Four Main Functions of the Heart?

Medically Reviewed on 3/4/2022

What are the four main functions of the heart?

Heart Illustration
The main functions of the heart include pumping blood, hormones, and other vital substances to other parts of the body

The four main functions of the heart are:

  • Pumping oxygenated blood to other body parts.
  • Pumping hormones and other vital substances to different parts of the body.
  • Receiving deoxygenated blood and carrying metabolic waste products from the body and pumping it to the lungs for oxygenation.
  • Maintaining blood pressure.

What is the structure of the human heart?

The heart is a muscular organ situated in the chest just behind and slightly toward the left of the breastbone. It roughly measures the size of a closed fist. The heart works all the time, pumping blood through the network of blood vessels called the arteries and veins. The heart and its blood vessels are known as the cardiovascular system.

The heart has four chambers. The upper two chambers are called the atria, whereas the lower two chambers are known as the ventricles. The right atrium and right ventricle are referred to as the right heart, whereas the left atrium and left ventricle are referred to as the left heart. The various chambers of the heart are separated by partitions, each of which is called a septum.

  • The right atrium receives deoxygenated blood from the body and pumps it to the right ventricle.
  • The right ventricle gets blood from the right atrium and pumps it to the lungs to load it with oxygen.
  • The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle.
  • The left ventricle is the strongest chamber of the heart. It pumps oxygen-rich blood to the rest of the body.

The flow of blood into the heart, within the heart chambers, and from the heart is guarded by the four valves present in the heart. The heart gets its nutrients and oxygen via the coronary arteries that run along the surface of the heart. It is also richly supplied by a web of nerve tissue that facilitates the rhythmic heartbeat. The heart is enclosed within a fluid-filled sac called the pericardium. The pericardium is a protective covering that produces fluid, which lubricates the heart and prevents friction between the heart and the surrounding organs.

What are the medical conditions related to the heart?

Some of the common diseases of the heart are:

  • Coronary artery disease (CAD): The narrowing of the arteries supplying blood to the heart (coronary arteries). If the arteries develop complete blockage from a suddenly lodged blood clot, the condition is called a heart attack.
  • Stable angina pectoris: Chest pain due to insufficient blood supply to the heart from doing strenuous physical activity. The reason is due to narrowed coronary arteries that are unable to supply sufficient oxygen-rich blood to the heart during exertion. Typically, there is relief from symptoms upon rest.
  • Unstable angina pectoris: Chest pain or discomfort is new in onset, worsening or occurring even at rest. Unstable angina pectoris is an emergency as it may precede a heart attack, serious abnormal heart rhythm or cardiac arrest.
  • Myocardial infarction (MI or heart attack): When a coronary artery is suddenly blocked, some of the heart muscles die as they are starved of oxygen.
  • Arrhythmia (dysrhythmia): Ann abnormal heart rhythm, which may interfere with the ability of the heart to pump blood effectively.
  • Congestive heart failure (CHF): In CHF, the heart is unable to pump blood to body tissues efficiently. The term congestive heart failure refers to the collection of fluid because of a failing heart.
  • Cardiomyopathy: A disease of the heart muscles, which makes the heart abnormally large, thickened and/or stiff. As a result, it weakens the ability of the heart to pump blood.
  • Myocarditis: The inflammation of the heart muscles.
  • Pericarditis: The Inflammation of the covering of the heart (pericardium).
  • Pericardial effusion: In this medical condition, there is a collection of fluid between the covering of the heart (pericardium) and the heart itself.
  • Heart valve diseases: Diseases that affect the valves that direct flow of blood to the heart.
  • Cardiac arrest: A sudden cessation of heart function.


In the U.S., 1 in every 4 deaths is caused by heart disease. See Answer

What is the difference between left and right heart catheterization?

Right heart catheterization goes through the artery, while left heart catheterization goes through the veins.
Right heart catheterization goes through the artery, while left heart catheterization goes through the veins.

Cardiac catheterization, also known as cardiac cath or heart cath, is a procedure to examine the functioning of the heart.

A thin, narrow tube called a catheter is inserted into a blood vessel of an arm or a leg, and is guided to the arteries of the heart using an X-ray camera. The doctor then injects contrast dye into the blood vessel through the catheter to get an X-ray view of the valves, arteries, and the heart chambers.

  • Catheterization of the left side of the heart is performed by passing the catheter through the artery.
  • In catheterization of the right side of the heart, the catheter passes through the veins.

Why is cardiac catheterization done?

Cardiac catheterization is done for diagnosing the following heart conditions:

  • Atherosclerosis: Deposits of fat, cholesterol, calcium, and clotting materials, known as fibrin in the innermost layer of arteries (endothelium), which results in clogging of the arteries.
  • Cardiomyopathy: Enlargement of the heart due to thickening or weakening of the heart muscle.
  • Congenital heart disease: Defects in one or more heart structures formed during fetal development.
  • Heart failure: A condition in which the heart muscles become too weak to pump blood well, leading to congestion in the blood vessels and lungs.
  • Heart valve disease: Failure of one or more heart valves, leading to reduced blood flow within the heart.
  • To determine the extent of coronary artery disease (CAD) in patients with confusing clinical presentations

Who should not undergo cardiac catheterization?

Patients with the following conditions shouldn’t undergo cardiac catheterization:

  • Severe uncontrolled blood pressure
  • Severe anemia
  • Kidney failure
  • Allergic to contrast dyes
  • Stroke
  • Heavy bleeding in the stomach and intestine
  • Abnormal changes in the electrolytes
  • Severe coagulopathy (impaired ability of the body to clot)
  • Ventricular arrhythmia (irregular heartbeat in the heart chamber)
  • Untreated infection or unexplained fever

How to prepare for a cardiac catheterization

Your physician will explain the procedure, along with its risks and benefits. In addition, you will also be instructed to do the following:

  • Sign an informed consent
  • What foods and liquids can be taken 24 hours before the test
  • Fast for six to eight hours before the cath procedure
  • Inform the doctor of any allergies to the dyes used in the cath procedure.
  • Inform the doctor about any medical and medication history, especially any drug allergies.
  • Stop taking specific medicines before the procedure.
  • Ask someone to accompany you during the procedure.

What happens during a cardiac catheterization?

  • Before the cath procedure, a nurse will put an intravenous (IV) line into the vein of the arm to inject sedatives to make you relax.
  • Your doctor will use a local anesthetic to numb the area, where the catheter goes in.
  • The groin area is cleaned and shaved. The doctor will puncture your skin with a needle to gain access to the blood vessel.
  • The doctor will insert an instrument known as an introducer sheath from which the catheter advances toward the blood vessels. You might feel some pressure. If you feel any pain, immediately inform the doctor.
  • When the catheter reaches the arteries, it will inject a small amount of dye into the arteries.
  • The X-ray camera will take pictures of your arteries and heart chambers. The catheter is removed gradually once the procedure ends.

What happens after cardiac catheterization?

You will be sent to the recovery room for a few hours. During this time:

  • Pressure will be applied to the puncture site to stop bleeding
  • You will have to lie straight on the bed. 
  • Your vital signs such as blood pressure and pulse will be checked during your recovery
  • Inform the doctor about any swelling, pain, or bleeding at the puncture site.

How serious is a heart catheterization?

A heart cath is generally very safe. But as with any procedure, there are some risks with heart catheterization too.

Risks include:

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Medically Reviewed on 3/4/2022
Medscape Medical Reference