Cardiac Glossary


Here are common cardiac terms you may hear when learning about a heart problem and treatment:

  • Aorta: The body’s largest artery. It carries oxygen-rich blood from the heart to the rest of the body
  • Aortic valve: A valve inside the heart that allows blood to flow forward from the left ventricle to the aorta.
  • Arrhythmia: An abnormal heart rhythm or rate.
  • Artery: A blood vessel that carries blood away from the heart.
  • Atresia: A condition in which a part of the heart, such as a valve, is absent at birth. This is because it didn’t develop the right way.
  • Atria (singular: atrium): The heart’s two upper chambers. They receive blood from the lungs (left atrium) and the body (right atrium).
  • AV (atrioventricular) node: The cluster of electrical cells in the heart. They receive signals from the atria and guide them to the ventricles.
  • Balloon valvuloplasty: A procedure that uses a balloon-tipped catheter to open a narrowed heart valve or vessel.
  • Bicuspid: A heart valve with two leaflets.
  • Biological valve: A heart valve created from human or animal tissue.
  • Blood vessels: Tubes that carry blood throughout the body. Arteries and veins are blood vessels.
  • Bradycardia or bradyarrhythmia: A type of arrhythmia during which the heart beats too slowly.
  • Bundle branches: Pathways of cells in the heart. They carry electrical signals from the AV node into the ventricles.
  • Cardio: Relating to the heart.
  • Cardiologist: A doctor with special training to diagnose and treat heart problems.
  • Cardiomyopathy: Structural and/or functional diseases of the heart’s ventricles not caused by coronary artery disease.
  • Catheter: A long, thin, flexible tube used during cardiac catheterization procedures. It helps obtain information about the heart or helps treat a heart problem.
  • Coarctation: Narrowing of a blood vessel.
  • Contrast dye: A special fluid that enhances x-rays of blood vessels. It allows blood flow to be tracked. Used for certain heart tests.
  • Coronary: Relating to the heart vessels that provide blood to the heart itself.
  • Coronary arteries: Blood vessels that wrap around the heart. They supply the heart muscle with oxygen-rich blood.
  • Cyanosis: A condition in which the skin, lips, and nails appear blue. This is due to low oxygen levels in the blood.
  • Ductus arteriosus: A blood vessel in the fetus that connects the pulmonary artery and the aorta. If it fails to close after birth, it’s called a patent ductus arteriosus (PDA).
  • Echocardiography (echo): A test that uses sound waves to create a picture of the heart. Also called a heart ultrasound.
  • Edema: A buildup of excess fluid in the body. Often shows up as swollen feet or ankles.
  • Electrocardiography (ECG or EKG): A test that records the way electrical signals move through the heart.
  • Foramen ovale: An opening between the two upper chambers of a fetus’s heart. If it fails to close after birth, it’s called a patent foramen ovale (PFO).
  • Homograft: A blood vessel with or without a heart valve from a human donor.
  • Hypertrophy: When the heart muscle thickens.
  • Hypoplastic: Abnormally small or undeveloped.
  • Insufficiency (regurgitation): When a heart valve doesn’t close tightly. It allows leakage or backward flow of blood.
  • IV (intravenous) line: A thin tube that delivers fluid to a vein.
  • Mechanical valve: A heart valve created from manmade material. This includes ceramic or metal.
  • Mitral valve: The valve inside the heart that allows blood to flow forward from the left atrium to the left ventricle.
  • Murmur: An extra noise made by the heart. It happens when blood doesn’t flow smoothly through the heart.
  • Palpitation: An irregular or skipped heartbeat.
  • Pulmonary artery: The large artery that carries blood from the heart to the lungs to get oxygen.
  • Pulmonary veins: Veins that carry oxygen-rich blood from the lungs to the heart.
  • Pulmonary valve: The valve inside the heart that allows blood to flow forward from the right ventricle to the pulmonary artery.
  • Risk factors: Behaviors and/or conditions that place a person at higher risk of having a problem or disease.
  • SA (sinoatrial) node: A cluster of electrical cells in the right atrium that starts each heartbeat.
  • Shunt: When blood flows from one location of the heart to another in the path of least resistance. It can also refer to a tube or device placed in the heart. The device allows blood to flow in a certain direction.
  • Stenosis: Narrowing that occurs at or near a heart valve or blood vessel. This obstructs blood flow.
  • Stent: A device that is placed in a blood vessel or heart valve. It helps keep it open.
  • Tachycardia or tachyarrhythmia: A type of arrhythmia during which the heart beats too fast.
  • Tricuspid valve: The valve inside the heart that allows blood to flow forward from the right atrium to the right ventricle.
  • Valves: “Doorways” that open and close. They allow blood to flow forward through the heart.
  • Vein: A blood vessel that carries blood toward the heart.Ventricles (singular: ventricle): The heart’s two lower chambers. They pump blood to the lungs (right ventricle) and the body (left ventricle).