Medical Terminology: Cardiovascular Terminology

1. What is the Cardiovascular system?
The cardiovascular system is responsible for delivery of blood, which carries oxygen and other nutrients to the tissues of the body. The heart pumps the blood to the body, where it delivers nutrients and oxygen, picks up waste products, and then returns to the heart.
The heart has four chambers. The upper chambers are the atria; the lower chambers are the ventricles. In the middle there is a septum, a wall that separates the right side of the heart from the left side of the heart. Atrioventricular (AV) valves control the blood flow between the upper and lower chambers of the heart.
The tricuspid valve is on the right side; the mitral valve is on the left side between the atria and the ventricle. The pulmonic valve controls the flow between the right ventricle and the pulmonary artery, whereas the aortic valve controls the flow between the left ventricle and the aorta.
Unoxygenated blood empties into the right atrium from the systemic circulation via the inferior vena cava and superior vena cava. As the right atrium contracts, the tricuspid valve opens, allowing the blood to flow into the right ventricle. With contraction of the right ventricle, the pulmonic valve opens, allowing the unoxygenated blood to enter the pulmonary artery to go to the lungs to pick up oxygen.
Once oxygenated, the blood returns to the heart via the pulmonary vein and enters the left atrium. As the left atrium contracts, the mitral valve opens, allowing the blood to flow into the left ventricle. As the left ventricle contracts, the aortic valve opens, allowing the blood to flow into the aorta and systemic circulation. The blood returns to the heart from the lower body via the inferior vena cava and from the upper body via the superior vena cava. The functions on the right side and left side of the heart happen simultaneously.
Therefore, when we listen to a normal heartbeat, the sounds we hear are the sounds of the valves closing. The mitral and tricuspid valves create the first heart sound (S1), whereas aortic and pulmonic valves create the second heart sound (S2).
The electrical conduction system of the heart starts at the sinoatrial (SA) node, which is located in the right atrium. It initiates the heart beat, ranging from 60. to 100. beats per minute, every day, for a lifetime.
The electrical current travels across both atria, then converges on the AV node where the current slows, allowing the atria to repolarize. The AV node is located in the superior portion of the ventricular septum. In the bottom portion are located the right and left bundle of His, which is a group of special cardiac muscles that send an electrical impulse to the ventricle to begin cardiac contractions.
These end in the Purkinje fibers and spread out through the ventricles. The current passing through these fibers causes ventricular contraction, forcing the blood from the right ventricle to the lungs, and the left ventricle to the aorta, thus creating systemic circulation.

2. Aortic Aneurysm
A weakening in the wall of a portion of the aorta results in a balloon-like bulge as blood flows through the aorta. The blood flow within this bulging area of the aorta becomes very turbulent. Over time, this turbulence can cause the dilated area to increase in size, creating an aneurysm. The aneurysm can rupture, causing a disruption in blood flow to everything below the affected area, and may even result in death.
This is commonly caused by atherosclerosis, in which fatty substances, cholesterol, calcium, and the clotting material fibrin (referred to as plaque), buildup in the inner lining of an artery and result in thickening and hardening of the arteries. It may also be caused by degeneration of the smooth muscle layer (middle) of the aorta, trauma, congenital defect, or infection. The aneurysm may be found incidentally on radiographic studies done for other reasons, or the patient may have developed symptoms indicating that something was wrong, such as severe back or abdominal pain, or a pulsating mass. Severe hypotension and syncope (fainting caused by insufficient blood supply to the brain) may indicate rupture.

3. Angina (Angina Pectoris)
A narrowing of blood vessels to the coronary artery, secondary to arteriosclerosis, results in inadequate blood flow through blood vessels of the heart muscle, causing chest pain. An episode of angina is typically precipitated by physical activity, excitement, or emotional stress. There are three categories of angina:
- Stable: The pain is relieved by rest or nitrates and symptoms are consistent.
- Unstable: The pain occurs at rest; is of new onset; is of increasing intensity, force, or duration; is not relieved by rest; and is slow to subside in response to nitroglycerin.
- Prinzmetal’s or Vasospastic: This usually occurs at rest or with minimal formal exercise or exertion; it often occurs at night.
Atherosclerotic heart disease occurs when there is a buildup of plaque within the coronary arteries. Angina is often the first symptom that heart disease exists. When the demand for oxygen by the heart muscle exceeds the available supply, chest pain occurs.

4. Myocardial Infarction (MI)
Blood supply to the myocardium is interrupted for a prolonged time because of the blockage of coronary arteries. This results in insufficient oxygen reaching cardiac muscle, causing cardiac muscles to die (necrosis). Myocardial infarction is commonly known as a heart attack. The area of infarction is often due to a buildup of plaque over time (atherosclerosis). It may also be caused by a clot that develops in association with the atherosclerosis within the vessel. Patients are typically (but not always) symptomatic. However, some patients are not aware of the event; they have what is called a silent MI.

5. Coronary Artery Disease (CAD)
Cholesterol, calcium, and other elements carried by the blood are deposited on the wall of the coronary artery, resulting in the narrowing of the artery and the reduction of blood flow through the vessel. This impedes blood supply to the heart muscle. These deposits start out as fatty streaks and eventually develop into plaque that inhibits blood flow through the artery. Elevated cholesterol levels and fat intake can contribute to this plaque buildup, as can hypertension, diabetes, and smoking. When the plaque builds up within the artery, the heart muscle is deprived of oxygen and nutrients, ultimately damaging the heart muscle.

6. Peripheral Arterial Disease (PAD)
Large peripheral arteries become narrowed and restricted (stenosis), leading to the temporary (acute) or permanent (chronic) reduction of blood flow to tissues (ischemia). This is most commonly caused by atherosclerosis (plaque on the inner walls of arteries), but may also be caused by a blood clot (embolism), or an inflammatory process. Severe peripheral arterial occlusive disease can lead to skin ulceration and gangrene. Peripheral arterial occlusive disease is more common in patients with diabetes or hypertension, older adults, those with hyper-lipidemia, and those who smoke, as these conditions can predispose the patient to diminished circulation. Vascular disease that happens in one area of the body (i.e., coronary arteries) is not an isolated process. The plaque buildup caused by long-term elevated cholesterol levels happens throughout the body. The most common area of involvement is the lower extremities.

7. Cardiac Tamponade
A large amount of liquid accumulates in the sack around the heart (pericardium), creating pressure on the heart that reduces the filling of ventricles with blood. This results in a low volume of blood being pumped with each contraction. The accumulating pressure within the pericardium may result from fluid, pus, or blood. The end result is decreased stroke volume and cardiac output. The cause of tamponade may be trauma, postoperative, post-MI, uremia, or cancer. The fluid may develop rapidly or over time, depending on the cause. Tamponade is a life-threatening condition. The seriousness is related to the amount of pressure within the heart and the resulting decrease in ventricular filling.

8. Cardiogenic Shock
Cardiogenic shock is caused by a drop in blood pressure and blood flow caused by the heart’s inability to pump blood as a result of a cardiac emergency such as cardiac tamponade, myocardial ischemia, myocarditis, or cardiomyo-pathy (a disease of the heart that deteriorates the heart function). Blood pools in the left ventricle, which causes a backup of blood into the lungs, resulting in pulmonary edema. Contractions increase to compensate for the decreased cardiac output causing an increase in demand for oxygen by the heart. However, the lungs are not oxygenating the blood sufficiently because of decreased blood flow; therefore, heart muscles are starved for oxygen.

9. Cardiomyopathy
The middle layer of the heart wall that contains cardiac muscle (myocardium) weakens and stretches, causing the heart to lose its pumping strength and become enlarged. The heart remains functional; however, contractions are weak, resulting in decreased cardiac output. Most are idiopathic and not related to the major causes of heart disease.
The three types of cardiomyopathy are:
- Dilated (Common): The heart muscle thins and enlarges, which leads to congestive heart failure. Progressive hypertrophy and dilatation result in problems with pumping action of ventricles.
- Hypertrophic: The ventricular heart muscle thickens, resulting in outflow obstruction or restriction. There is some blood flow present.
- Restrictive (Rare): The heart muscle becomes stiff and restricts blood from filling ventricles, usually as a result of amyloidosis, radiation, or myocardial fibrosis after open heart surgery.

10. Endocarditis
Microorganisms, usually bacteria, enter the bloodstream and attach to the inner lining of the heart (endocardium) and heart valves, resulting in inflammation. Ulceration and necrosis occur when microorganisms cover the heart valves. This usually occurs in patients with rheumatic or degenerative heart disease; those with recent instrumentation [IV, genitourinary (GU), and respiratory procedures] or dental procedures; and IV drug users.

11. Heart Failure [Congestive Heart Failure (CHF)]
In congestive heart failure (CHF), the heart is unable to pump sufficient blood to maintain adequate circulation. This result in a backup of blood and the extra pressure may cause accumulation of fluid. Heart failure is primarily caused by problems with ventricular pumping action of the cardiac muscle, which may be caused by diseases such as MI (heart attack), endocarditis (infection in the heart), hypertension (high blood pressure), or valvular insufficiency. When disease affects primarily the left side of the heart, the blood backs up into the lungs. When disease affects primarily the right side of the heart, systemic circulation may be overloaded. When the heart failure becomes significant, the whole circulatory system may become compromised.

12. Hypertension
Pressure inside blood vessels exceeds 140. mm Hg systolic and 90. mm Hg diastolic on more than one occasion resulting from a primary disease or no known cause. These are the classifications of hypertension:
- Normal: <120. mm Hg systolic / <80. mm Hg diastolic
- Prehypertension: 120–139. mm Hg systolic / 80–89. mm Hg diastolic
- Stage 1: 140–159. mm Hg systolic / 90–99. mm Hg diastolic
- Stage 2: 160. mm Hg systolic / 100. mm Hg diastolic
- Diabetes Hypertension: >130. mm Hg systolic / >80. mm Hg diastolic

13. Hypovolemic Shock
Rapid fluid loss causes inadequate circulation, resulting in inadequate perfusion of organs. Hypovolemic shock can be caused by external hemorrhage, fluids moving in the body from vessels into tissue (third spacing), or dehydration. External hemorrhage is loss of blood, plasma, fluids, and electrolytes because of trauma, gastrointestinal bleed, vomiting, or diarrhea. Third spacing can result from ascites or pancreatitis.

14. Myocarditis
Inflammation of the heart muscle is usually caused by infection, most often viral. Infection can also be caused by alcohol poisoning from chronic alcohol abuse, drugs, or diseases that can result in the degeneration of heart muscle. This reduces the ability of the heart to pump blood efficiently, leading to CHF.

15. Pericarditis
The membrane that encloses the heart (pericardium) is inflamed. Pericarditis is either acute or chronic. Acute pericarditis is most commonly associated with viral infections. Upper respiratory symptoms are not uncommon and can occur a few weeks before the onset of pericarditis. Pericarditis may be caused by any infectious agent, acute myocardial infarction (AMI), malignancy, autoimmune diseases, or drug reaction.

16. Pulmonary Edema
Fluid builds up in the lungs from ineffective pumping of blood by the heart as a result of left-sided heart failure, AMI, worsening of heart failure, or volume overload. The patient experiences hypoxia, which is insufficient oxygen supply to tissues, caused by decreased oxygenation of the blood. Several noncardiac issues may lead to pulmonary embolism.

17. Raynaud’s Disease
Blood flow to the extremities decreases as peripheral arteries narrow from vasospasm when exposed to cold or emotional stress. This results in the fingers, toes, nose, and ears blanching to a pale shade and/or turning blue and red as blood flow decreases. It usually occurs bilaterally, often sparing the thumbs, and begins to resolve with warming of affected areas. Raynaud’s is a benign condition usually controlled by avoidance of underlying factors (i.e., cold and stress). Secondary Raynaud’s can be seen with other disorders, mostly inflammatory and/or connective tissue diseases. This is more common in older men, usually involves the hands, and can have other complications.

18. Rheumatic Heart Disease
Rheumatic fever usually results from a prior upper respiratory infection with group A streptococcus. It may lead to permanent valve disease and cardiac damage, with the mitral valve being more commonly affected.

19. Thrombophlebitis
Thrombophlebitis is the inflammation of a vein as a result of the formation of one or more blood clots (thrombus). It is usually seen in the lower extremities, calves, or pelvis. This may be the result of injury to the area, may be precipitated by certain medications or poor blood flow, or may be the result of a coagulation disorder.

20. Atrial Fibrillation
Uncoordinated firing of electrical impulses in the wall of the atria (upper chambers of the heart) causes the heart to quiver instead of beat regularly, resulting in ineffective contractions. This is usually caused by an abnormality in the electrical system of the heart. Blood is ineffectively pumped to the ventricles (lower chambers of the heart) and may result in not enough blood being pumped throughout the body. Usually the heart beats rapidly; however, this is not always the case. Atrial fibrillation (also called AF or “a fib”) is the most common chronic arrhythmia and is not life threatening on its own, but increases the patient’s risk for blood clots and strokes.

21. Asystole
Asystole is defined as no cardiac electrical activity. This causes ventricles to stop contractions, leading to no cardiac output and no blood flow. Cardiac standstill is a medical emergency. Treatment must be started immediately, while simultaneously attempting to understand the etiology of a nonbeating heart. Asystole is a criterion for certifying that the patient is dead. Asystole may be caused by disruption in the electrical conduction system, causing life-threatening arrhythmias, sudden cardiac death, hypovolemia, cardiac tamponade, massive pulmonary embolism, AMI, metabolic disorder, or drug overdoses. In case of a drug overdose—usually PEA (pulseless electrical activity)—reverse overdose or treat.

22. Ventricular Fibrillation
Electrical impulses that trigger the ventricles to contract fire erratically. This causes the ventricles to quiver and prevents regular effective contractions, resulting in the disruption of blood flow to the body. The usual causes are ventricular tachycardia, electrolyte disturbances, MI, electric shock, and drug toxicities.

23. Ventricular Tachycardia
Abnormal electrical impulses within the ventricles cause the heart to contract more than 160. beats per minute. This results in inadequate filling of the ventricles with blood between beats; subsequently, less blood is pumped throughout the body than during normal contractions. Ventricular tachycardia (called “V tach”) often occurs after AMI and in cardiomyopathy, coronary artery disease (CAD), mitral valve prolapse, and other myocardial disease.

24. Aortic Insufficiency (AI)
Leakage of the aortic valve causes blood to flow back into the left ventricle. This results in increased blood volume in the left ventricle, causing it to dilate and become hypertrophic, thus reducing blood flow from the heart. The usual cause is incompetent cusps or leaflets of the valve, from endocarditis, valve structural problems, connective tissue disorders, rheumatic heart disease, hypertension, arteriosclerosis, and other conditions.

25. Mitral Insufficiency
Leakage of the mitral valve causes blood to flow back from the left ventricle into the left atrium. As a result, blood might flow back into the lungs. Mitral regurgitation is caused by an incompetent valve, damaged from rheumatic fever, CAD, or endocarditis.

26. Mitral Stenosis
In mitral stenosis, scar tissue secondary to rheumatic fever forms on the mitral valve. This causes it to narrow, increasing resistance to blood flow between the left ventricle and left atrium, which means the heart needs to pump harder to maintain blood flow.

27. Mitral Valve Prolapse
The mitral valve bulges back into the left atrium, allowing blood to flow backward from the left ventricle into the left atrium. This is a common problem and is not considered a serious condition. It is often congenital.

28. Tricuspid Insufficiency
Leakage in the tricuspid valve causes a backflow from the right ventricle into the right atrium. This results in increased pressure in the atrium and higher resistance to blood flowing from veins, causing enlargement of the right atrium. This may occur from an anatomic problem, but usually occurs from right ventricular overload (in turn caused by left ventricular overload). It may also occur because of an inferior MI, or damage from endocarditis.

29. Cardiac Catheterization (Angiography)
This is an invasive procedure used to examine the coronary arteries and intracardiac structures, as well as to measure cardiac output, intracardiac pressures, and oxygenation.
A radiopaque dye, which makes structures visible on X-rays, is injected through a catheter into the femoral artery in the patient’s left leg or in the antecubital fossa, which is the crease of the arm; it then flows to the coronary arteries. The flow of the radiopaque dye is viewed and recorded using a fluoroscope, enabling the health care provider to determine obstructions to the flow and the structures of the heart.

30. Echocardiograph
An ultrasound of the heart provides a noninvasive examination of intracardiac structures and blood flow. Sound waves are directed to and deflected by the heart, causing an echo that is detected by the echocardiograph, which is interpreted by a health care provider.

31. Nuclear Cardiology
These tests determine myocardial perfusion and contractility of the heart, ischemia, infarction, wall motion, and ejection fraction. Radioisotopes are injected through the IV. The radiation detector monitors the flow of the radioisotope as it flows through the heart.

32. Digital Subtraction Angiography
Digital subtraction angiography enables the health care provider to view arterial blood supply to the heart using an injection of radiopaque contrast material. The patient is injected with an intravascular contrast material containing iodine. Images of bone and soft tissue are viewed from fluoroscopy through the use of a computer, enabling the health care provider to view the cardiovascular system.

33. Hemodynamic Monitoring
Hemodynamic monitoring measures cardiac output and intracardiac pressure. A balloon-tipped catheter is inserted into the pulmonary artery, usually through the femoral artery. It is able to measure pressures in the heart’s various chambers and vessels.

34. Venogram
This determines if the patient has incomplete valves or deep vein thrombosis. An iodine dye is injected into the vein, making the vein visible in a fluoroscope; this allows the health care provider to visualize the flow of venous blood.

35. Pulse Oximetry
This determines the abbreviated arterial oxygen saturation of the blood. The full arterial oxygen saturation is determined by the arterial blood gas test.
An infrared light passes through the patient’s nailbed or skin. The amount of infrared light passing through determines the amount of arterial oxygen saturation of the blood.

Basic Questions
Cardiovascular Terminology

1. What is an aortic aneurysm?
An aortic aneurysm is a weakening in the wall of a portion of the aorta resulting in a balloon-like bulge as blood flows through the aorta.

2. What is a common cause of an aortic aneurysm?
An aortic aneurysm is commonly caused by atherosclerosis, in which fatty substances, cholesterol, calcium, and the clotting material fibrin, referred to as plaque, buildup in the inner lining of an artery, resulting in thickening and hardening of the arteries.

3. What is angina pectoris?
Angina pectoris is a narrowing of blood vessels to the coronary artery, secondary to arteriosclerosis, resulting in inadequate blood flow through blood vessels of the heart muscle, causing chest pain.

4. What is Prinzmetal’s angina?
Prinzmetal’s angina usually occurs at rest or with minimal formal exercise or exertion; it often occurs at night.

5. What is a myocardial infarction (MI)?
Blood supply to the myocardium is interrupted for a prolonged time because of the blockage of coronary arteries. This results in insufficient oxygen reaching cardiac muscle, causing cardiac muscles to die (necrosis). Myocardial infarction is commonly known as a heart attack.

6. What is peripheral arterial disease (PAD)?
Large peripheral arteries become narrowed and restricted (stenosis), leading to the temporary (acute) acute permanent (chronic) reduction of blood flow to tissues (ischemia). This is most commonly caused by atherosclerosis (plaque on the inner walls of arteries), but may also be caused by a blood clot (embolism), or an inflammatory process.

7. What is cardiac tamponade?
A large amount of liquid accumulates in the sack around the heart (pericardium), creating pressure on the heart that reduces the filling of ventricles with blood.

8. What is a common cause of cardiac tamponade?
The accumulating pressure within the pericardium may result from fluid, pus, or blood.

9. What is the result of cardiac tamponade?
Cardiac tamponade results in a low volume of blood being pumped with each contraction. The end result is decreased stroke volume and cardiac output.

10. What is cardiogenic shock?
Cardiogenic shock is a drop in blood pressure and blood flow caused by the heart’s inability to pump blood as a result of a cardiac emergency.

11. What are common causes of cardiogenic shock?
Common causes of cardiogenic shock are cardiac tamponade, myocardial ischemia, myocarditis, or cardiomyopathy.

12. What is cardiomyopathy?
The middle layer of the heart wall that contains cardiac muscle (myocardium) weakens and stretches, causing the heart to lose its pumping strength and become enlarged.

13. What is a common result of cardiomyopathy?
The heart remains functional; however, contractions are weak, resulting in decreased cardiac output.

14. What is hypertrophic cardiomyopathy?
The ventricular heart muscle thickens, resulting in outflow obstruction or restriction. There is some blood flow present.

15. What is endocarditis?
Microorganisms, usually bacteria, enter the bloodstream and attach to the inner lining of the heart (endocardium) endocardium heart valves, resulting in inflammation.

16. Why should a health care provider anticipate endocarditis developing?
This usually occurs in patients with rheumatic heart disease or degenerative heart disease; those with recent instrumentation [IV, genitoutinary (GU), and respiratory procedures] or dental procedures; and IV drug users.

17. What is congestive heart failure (CHF)?
In CHF, the heart is unable to pump sufficient blood to maintain adequate circulation. This result in a backup of blood, and the extra pressure may cause accumulation of fluid.

18. What causes CHF?
Heart failure is primarily caused by problems with ventricular pumping action of the cardiac muscle, which may be caused by diseases such as MI (heart attack), endocarditis (infection in the heart), hypertension (high blood pressure), or valvular insufficiency.

19. When does fluid back up into the lungs in CHF?
When disease affects primarily the left side of the heart, the blood will back up into the lungs.

20. When does fluid back up into the circulation in CHF?
When disease affects primarily the right side of the heart, the systemic circulation may be overloaded.

21. What is hypovolemic shock?
Rapid fluid loss causes inadequate circulation, resulting in inadequate perfusion of organs.

22. What are common causes of hypovolemic shock?
Hypovolemic shock can be caused by external hemorrhage, fluids moving in the body from vessels into tissue (third spacing), or dehydration.

23. What is pericarditis?
Pericarditis occurs when the membrane that encloses the heart (pericardium) is inflamed.

24. What is Raynaud’s disease?
Blood flow to the extremities decreases as peripheral arteries narrow from vasospasm when exposed to cold or emotional stress. This results in the fingers, toes, nose, and ears blanching to a pale shade and/or turning blue and red as blood flow decreases.

25. What is thrombophlebitis?
Thrombophlebitis is the inflammation of a vein as a result of the formation of one or more blood clots (thrombus).