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Chapter_12
Term | Definition |
---|---|
heart disease | any disease that affects the heart |
cardiovascular system | the system, which includes the heart and blood vessels, that moves blood throughout the body |
artery | a blood vessel that carries blood away from the heart |
vein | a blood vessel that carries blood back to the heart from the tissues |
capillary | tiny blood vessels where oxygen and nutrient exchange between blood and tissues occurs |
oxygen | a colorless tasteless odorless gas constituting 21% of the air we breathe |
carbon dioxide | a colorless, odorless, incombustible gas present in the atmosphere and formed during respiration |
cardiac muscle | fibers that make up the walls of the heart |
atrium | a chamber of the heart that receives the blood brought to the heart |
ventricle | a lower chamber of the heart that receives blood from the atria and pumps it out of the heart |
systole | the time period during which the heart is contracting and actively pumping blood |
diastole | the time period when heart muscle relaxes, allowing blood to passively flow in and fill up the heart chambers |
sinoatrial (SA) node | a bundle of conduction fibers in the right atrium that starts the electrical charge to initiate each heart beat; often called the heart’s natural pacemaker |
atrioventricular (AV) node | an area of tissue that conducts electrical signal from the atria to the ventricles |
bundle of His | a bundle of heart muscle cells that conducts electrical signals from the atrioventricular node to the Purkinje fibers |
Purkinje fibers | fibers in the heart that stretch into the ventricles to contract the lower—and largest—part of the heart |
heart rate (HR) | the number of heart beats, or contractions, per minute |
beats per minute (BPM) | the measurement of heart beats, or contractions, per minute |
pulse | another term for heart rate; measured by feeling for heart beats in an artery through the skin |
electrocardiogram (ECG or EKG) | a mechanical measurement of electrical signal flowing through the heart then depicted graphically |
blood pressure (BP) | the force of blood that fills the circulatory system |
capacitance | how much blood is held in the circulatory system |
peripheral vascular resistance (PVR) | how constricted or relaxed the blood vessels are |
cardiac output (CO) | the force and volume of blood coming from the heart |
renin-angiotensin system | a feedback mechanism that is regulated by the kidneys and balances fluid volume and vessel constriction |
shock | a condition during which vital organs are not perfused with blood and begin to die; usually related to a drastic drop in blood pressure |
sphygmomanometer | an instrument used to measure blood pressure |
systolic reading | the first or upper number reported in a blood pressure reading when the blood starts flowing again after being briefly cut off with a blood pressure cuff |
diastolic reading | the lower number in a blood pressure result, taken at the point at which the cuff is loose enough that blood freely flows without turbulence through the artery |
stepped therapy | a systematic method of using drug therapy that starts with one drug and then other agents are added one by one, based on a patient’s conditions |
hypertension | high blood pressure (140/90 or higher ) |
angiotensin-converting enzyme (ACE) inhibitors | a class of drugs that regulate blood pressure through the renin–angiotensin system |
renin | an enzyme produced by the kidneys and is converted to angiotensin I in the bloodstream |
angiotensin I | a vasoconstrictor that narrows blood vessels |
angiotensin II | a potent vasoconstrictor that narrows blood vessels |
angiotensin-converting enzyme (ACE) | an enzyme that converts angiotensin I to angiotensin II |
angioedema | a rare but serious side effect of some drugs that causes an allergic-like reaction wherein swelling of the tongue and face are severe enough to threaten breathing |
hypotension | low blood pressure (90/60 or lower) |
angiotensin receptor blockers (ARBs) | a class of drugs that block the action of angiotensin II, preventing constriction and causing blood vessels to relax, which lowers blood pressure |
calcium-channel blockers | a class of drugs used to decrease blood pressure by preventing calcium from entering into smooth muscle cells in arterial walls |
diuretics | drugs that help the kidneys eliminate sodium and fluid from the body, which decreases blood volume and lowers blood pressure |
adrenergic inhibitors | drugs that block alpha and beta receptors, adrenaline receptor types found in the body |
beta blockers | a class of drugs that block beta receptors on sympathetic nerves which lowers blood pressure and slows heart beat; used to treat hypertension, angina, and arrhythmias |
alpha blockers | a class of drugs that block alpha receptors in arteries and smooth muscle to produce lower blood pressure; used to treat hypertension |
sinus rhythm | normal heart rhythm set by the sinus node, or pacemaker |
arrhythmia | any deviationin heart rhythm from normal, regular (sinus) rhythm |
tachycardia | an increased heart rate |
bradycardia | a decreased heart rate |
flutter | an irregular heart rhythm occurring when select portions are slightly out of sync with the rest of the heart |
fibrillation | an irregular heart rhythm that can be life threatening and occurs when large portions of the heart beat out of sequence |
antiarrhythmic agents | four classes of arrhythmia drugs categorized by their mechanisms of action |
membrane stabilizing agents (class I) | an antiarrhymthmic group of drugs containing a few different drug classes that all happen to block sodium channels in cardiac muscle cells |
beta blockers (class II) | a class of an antiarrhymthmic drugs containing certain beta blockers that inhibit beta-one receptors on the heart |
potassium-channel blockers (class III) | a class of antiarrhymthmic drugs that block potassium channels in cardiac muscle cells |
calcium-channel blockers (class IV) | a class of drugs, used for atrial fibrillation, that block calcium, another cation, from entering cardiac muscle cells |
angina pectoris | a chest pain caused by inadequate blood flow to a portion of the heart |
myocardial ischemia | a condition that occurs as a result of a blockage in the coronary arteries that supply the heart itself with blood; literally means heart tissue death |
stable angina | a predictable pattern of chest pain and tightness that happens in response to specific triggers, such as exercise, physical pain, emotional stress, exposure to cold, or smoking |
unstable angina | chest pain and tightness that occurs with increasing frequency and less predictability |
variant angina | a type of chest pain that involves spasm of the coronary blood vessels, rather than blockage |
myocardial infarction (MI, heart attack) | the death of heart muscle due to a blockage |
cardiac catheterization | a procedure to reopen blocked arteries in the heart |
coronary bypass surgery | a procedure where a vessel from the leg is used to create an arterial bypass around a blockage in a coronary artery, thus restoring blood flow to previously blocked off heart tissue |
stents | supportive structures made of metal wire mesh used to keep coronary arteries open |
emergency room drug kits | part of a crash cart or othey emergency kit that contains drugs and equipment needed to aid in cardiac arrest or other emergencies like siezure |
crash carts | a portable unit containing all equipment and medications most likely needed to aid in cardiac arrest or other emergencies like siezure |
nitrates | a class of drugs are used to treat and prevent angina attacks by dilating blood vessels to reduce stress on the heart |
vasodilators | drugs used to relax smooth muscle and dilate blood vessels, which relieves chest pain and ischemia |
heart failure | when heart function is so weak that it cannot circulate blood adequately; symptoms include weakness, fatigue, severe fluid retention, and difficulty breathing due to pulmonary edema (fluid accumulation in the lungs) |
hyperlipidemia | a condition of elevated cholesterol, phospholipids, and/or triglycerides in the blood and leads to cardiovascular disease and coronary artery blockage |
cholesterol | a substance made within the body and ingested with foods which is used to build cell membranes and form hormones; excess of it contributes to atherosclerosis and heart disease |
low-density lipoproteins (LDL) | the worst type of cholesterol that contributes to artery blockages |
high-density lipoproteins (HDL) | the good kind of cholesterol that helps to break up plaques and blockages in blood vessels |
triglycerides | a kind of lipid molecule, contributing to atherosclerosis (blocking and hardening of artery walls due to fat buildup |
HMG-CoA reductase inhibitors | a drug class that lowers LDL cholesterol and can have beneficial effects on other lipids as well; used to treat hyperlipidemia |
statins | a class of drugs that reduces the amount of cholesterol made in the body by blocking an enzyme HMGCoA reductase |
HMG-CoA reductase | an enzyme which is required for cholesterol production |
fibrates | "a class of drugs used daily to lower high cholesterol, especially elevated triglycerides" |
niacin (vitamin B3, nicotinic acid) | a dietary supplement that reduces triglycerides and LDL cholesterol while raising HDL cholesterol |
omega 3 fatty acids (DHA, EPA) | polyunsaturated fatty acids available in a variety of fish oil products; used to treat high cholesterol, hypertension, and coronary artery disease |
plant sterol esters | a dietary supplement that canhelp to lower LDL cholesterol; can be a helpful adjunct to diet and drug therapy for hyperlipidemia |
beta-sitosterol | a plant sterol similar in chemical structure to cholesterol used in food products for cardiovascular disease |
alpha tocopherol (vitamin E) | an antioxidant that protect cells against the effects of free radicals; can be used for cardiovascular disease, cancer, and diabetic neuropathy |
garlic | a plant containing organosulfur compounds that have antihyperlipidemic, antihypertensive, and antifungal effects |
allicin | the odorous, active ingredient produced upon crushing garlic cloves |