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
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
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