Cardiovascular Health Glossary

by Urmila Parlikar, MS

• Aneurysm—weak, bulging area of an artery that is prone to a leak or rupture
• Angina—chest pain caused by insufficient blood flow to the heart
• Angiography—diagnostic procedure that produces images of large and medium-sized arteries throughout the body
• Aorta—the largest of the body’s arteries; blood flows from the heart, through the aorta, to the rest of the body
• Arrhythmias—abnormal pattern of electrical conduction through the heart
• Artery—blood vessel that carries blood away from the heart
• Arterioles—branches of smaller arteries that connect the arterial system to the capillaries
• Atherosclerosis—a disease process characterized by a buildup of fatty deposits and cellular debris inside artery walls that may impede blood flow
• Atrioventricular (AV) Node—mass of conducting tissue in the lower right atrium that slows the electrical impulses as they pass from the atria to the bundle of His in the ventricles
• Atrioventricular (AV) Valves—one-way valves located between the atria and ventricles
• Atria—upper chambers of the heart, which collect blood from the veins
• Bundle of His—cardiac fibers that conduct electrical impulses from the atria into the ventricles
• Bradycardia—slow cardiac rate defined as less than 60 beats/minute
• Capillaries—the smallest, most thinly-walled blood vessels; site of oxygen, nutrient, and waste exchange between blood and body tissues
• Cardiac Circulation—also called coronary circulation; flow of blood through blood vessels supplying the heart muscle
• Cardiovascular Disease—a collection of conditions that affect the heart and blood vessels
• Conduction System—a network of specialized cardiac tissue that initiates and transmits electrical signals in the heart
• Coronary Artery Disease (CAD, Coronary Heart Disease)—atherosclerotic blockage of arteries that feed that heart muscle; can lead to angina or heart attack
• Coronary Sinus—a large vein that empties blood from the coronary circulation into the right atrium
• Diastole—relaxation of the ventricles, during which time they fill with blood
• Doppler Ultrasound—echocardiographic technique that uses color coding to illustrate the direction and velocity of blood flow through the heart chambers and vessels
• Duplex Venous Ultrasound—noninvasive vascular study that uses ultrasound technology to visualize the flow of blood in veins
• Echocardiography—test that using ultrasound technology to produce moving images of chambers, valves, and blood flow of the heart
• Electrocardiogram—test used to examine the rhythm and electrical activity of the heart
• Electrophysiology Study—test used to assess electrical conduction abnormalities that increase the risk of life threatening arrhythmias; often used in preparation for the implantation of an artificial pacemaker
• Embolism—sudden obstruction of a blood vessel by a clot, atherosclerotic plaque, air bubble or other object circulating in the blood
• Endocardium—innermost layer of the heart; forms continuous extension of endothelium lining the blood vessels
• Endothelium—innermost layer of blood vessels made of up a single continuous sheet of endothelial cells; initial site of atherosclerosis
• Fatty Streaks—build up of fatty particles in the endothelium
• Gap Junctions—electrical synapses in the heart muscle
• Glucose Intolerance—ineffective control of blood sugar levels usually due to insulin resistance; risk factor for type 2 diabetes
• Heart Attack—also called myocardial infarction; death of heart muscle cells due to a sustained lack of oxygen
• Heart Failure—a condition in which the heart is incapable of pumping sufficient blood to meet the needs of the body
• Hemoglobin—protein in red blood cells that allows them to efficiently absorb, transport, and release oxygen throughout the body
• High-density Lipoproteins—protein-containing particles that carry cholesterol and other fats from blood vessels to the liver; high levels are protective against atherosclerosis
• Infarction—death of tissue due to sustained lack of oxygen
• Insulin Resistance—reduced sensitivity to insulin; hallmark of glucose intolerance and type 2 diabetes
• Intima—inner layer of arteries that make up the endothelium; initial site of atherosclerosis
• Ischemia—inadequate oxygen supply to a tissue
• Leukocytes—also called white blood cells; active in the body’s immune system
• Low-density Lipoproteins—protein-containing particles that carry cholesterol and other fats from the liver to cells throughout the body; high levels contribute to atherosclerosis
• Myocardium—heart muscle
• Myocardial Infarction—also called heart attack; death of heart muscle cells due to a sustained lack of oxygen
• Myocardial Ischemia—inadequate oxygen supply to the myocardium; occurs when the demand for oxygen exceeds its supply
• Myocardial Perfusion Imaging—imaging procedure that uses radioactive isotopes to assess how well blood is reaching the heart muscle
• Oxidation—a common chemical reaction involving oxygen; lipids in the endothelium become oxidized as part of the atherosclerotic process
• Pacemaker—conducting tissue that spontaneously initiates each cardiac cycle, setting the pace of the heart; normally the sinoatrial (SA) node; artificial pacemaker is an implantable device that paces the heart when its natural pacemaker fails
• Pericardium—membrane surrounding the heart
• Peripheral Artery Disease (PAD)—atherosclerosis in arteries that carry blood to the legs
• Plaque—an atherosclerotic lesion
• Plasma—liquid component of blood; composed primarily of water; contains electrolytes, proteins, nutrients, waste products, hormones, and drugs
• Platelets—blood component consisting of cellular remnants that aid in blood clot formation
• Pulmonary Arteries—transport deoxygenated blood from the right ventricle to the lungs
• Pulmonary Circulation—flow of blood from the right ventricle of the heart through the lungs and into the heart’s left atrium
• Pulmonary Veins—transport oxygenated blood from the lungs into the left atrium
• Purkinje Fibers—conducting tissue that carries electrical impulses from the bundle of His to the myocardium of the ventricles
• Red Blood Cells—cells that carry oxygen and carbon dioxide throughout the body
• Semilunar Valves—located at the base of the pulmonary artery and aorta allowing blood to flow to the pulmonary and systemic circulation respectively; prevent backflow of blood into the ventricles
• Septum—muscular wall separating the left and right sides of the heart
• Sinoatrial (SA) Node—also known as a pacemaker; mass of conducting tissue in the upper right atrium that normally sets the pace of the heart
• Stroke—also known as cerebral infarction or cerebrovascular accident (CVA); death of brain cells due to sustained lack of oxygen
• Systole—contraction of the ventricles, during which blood is ejected from the heart
• Systemic Circulation—flow of blood throughout the entire body, with the exception of the lungs
• Tachycardia—excessively rapid heart rate; usually defined as more than 100 beats/min at rest
• Thrombosis—development or presence of a blood clot
• Triglycerides—the chemical form in which most fat is stored in the body
• Veins—blood vessels that return blood to the heart
• Venae Cavae—2 large veins carrying blood directly to the right atrium of the heart
• Venography—uses injected dyes and x-rays to examine the interior of veins
• Ventricle—chamber of the heart that receives blood from the atrium and pumps it into the arteries
• White Blood Cells—also called leukocytes; active in the body’s immune system

Last reviewed October 2016 by Michael Woods, MD
Last Updated: 12/20/2014