Cardiovascular System, Shock, and Vascular Disorders

Vocabulary practice flashcards covering shock, stages of shock, cardiac conduction, valvular heart diseases, inflammatory heart disorders, myocardial infarction, and peripheral vascular disorders.

Shock

A life-threatening condition characterized by inadequate oxygen and arterial blood flow to tissues and cells.

Hypovolemic Shock

The most common type of shock, caused by circulating blood or fluid volume loss (e.g., from blood loss, diarrhea, diuresis, or severe dehydration).

Distributive Shock

Also known as normovolemic shock, occurring when peripheral blood vessels massively dilate, leading to decreased vascular resistance and inadequate tissue perfusion while fluid sits outside blood vessels.

Neurogenic Shock

The rarest form of distributive shock caused by a loss of sympathetic tone (due to spinal cord injury, opioid overdose, or general anesthesia), uniquely resulting in bradycardia and hypotension.

Septic Shock

A type of distributive shock triggered by severe infection (toxic shock) leading to massive whole-body vasodilation, drop in blood pressure, impaired perfusion, and a high risk of death ($40\text{--}50\%$).

Obstructive Shock

Shock resulting from a physical blockage of blood flow.

Cardiogenic Shock

Shock that occurs when the heart fails as an effective pump and cannot pump enough blood to meet the body's needs, leading to decreased cardiac output and impaired tissue perfusion.

Compensation Stage of Shock

The initial stage of shock where the body attempts to maintain homeostasis and keep blood and oxygen going to vital organs via bronchodilation, decreased urine output (kidneys conserving water), increased heart rate, increased contractility, and increased venous return.

Decompensation Stage of Shock

The stage occurring when compensatory mechanisms fail, resulting in cellular hypoxia, reduced ATP production, and cell damage or destruction.

Irreversible Stage of Shock

The final stage of shock where cell and organ damage is so severe that treatment can no longer reverse it, culminating in multiple system organ failure and imminent death.

Sarcopenia

Changes in muscle tissue composition that can occur in aging due to deconditioning, resulting in the loss of skeletal muscle mass, strength, and physical function.

Sinoatrial (SA) Node

The primary and natural pacemaker of the heart, located in the right atrium, which normally generates impulses at a rate of $60\text{--}100\,\text{b/m}$.

Atrioventricular (AV) Node

A component of the conduction system that briefly holds and delays the electrical signal, allowing the ventricles time to fill with blood before contracting.

Purkinje Fibers

Specialized cardiac fibers that spread electrical signals throughout the ventricles, causing ventricular contraction.

Polarization

The resting state of a cardiac cell, where it is ready to receive and respond to the next electrical impulse.

Depolarization

The electrical activation of cardiac cells as the impulse travels through, triggering muscular contraction.

Repolarization

The electrical recovery or reset phase during which cardiac cells return to their resting state.

Refractory Period

A brief period during which cardiac cells temporarily cannot respond normally to another electrical impulse, preventing continuous contraction and allowing time for relaxation and filling.

Cardiac Output

The volume of blood pumped by the heart per minute ($\text{CO} = \text{HR} \times \text{Stroke volume}$; normal range is $4\text{--}8\,\text{L/min}$).

$S_3$ Heart Sound

An extra heart sound heard after $S_2$, indicative of volume overload or heart failure.

Rheumatic Carditis

Inflammation of the heart caused by rheumatic fever following a Group A Streptococcal infection (strep throat), which can damage heart valves and produce a new heart murmur.

Infective Endocarditis

An infection and inflammation of the inner lining of the heart (endocardium), particularly affecting heart valves when microorganisms (such as Streptococci) attach to them.

Osler Nodes

Painful nodules found typically on the fingers and toes in clients with infective endocarditis ("O = ouch").

Janeway Lesions

Painless erythematous spots on the palms and soles associated with infective endocarditis.

Petechiae

Tiny, pinpoint red or purple spots on the skin caused by small areas of bleeding.

Pericarditis

Inflammation of the pericardium (the outer sac surrounding the heart) with or without effusion, characterized by chest pain that worsens with movement and breathing, and improves when sitting upright and leaning forward.

Cardiac Tamponade

A medical emergency caused by fluid accumulation in the pericardial sac that compresses the heart, preventing the ventricles from filling normally and causing severe hypotension and reduced cardiac output.

Pulsus Paradoxus

An assessment finding associated with cardiac tamponade characterized by an abnormal drop in systolic blood pressure (typically greater than $10\,\text{mm Hg}$) during inhalation.

Pericardiocentesis

A surgical/medical procedure using a needle or catheter to aspirate fluid from around the heart.

Buerger Disease

Inflammation of small and medium blood vessels, mainly in the arms and legs, associated with clot formation, fibrosis, and tobacco/nicotine use, which can lead to severe ischemia and tissue death.

Aortic Stenosis

A condition where the aortic valve cusps become stiff, rigid, and narrowed, forcing the left ventricle to pump harder and leading to left ventricular hypertrophy and decreased cardiac output.

Water-Hammer Pulse

A classic sign of aortic regurgitation where the radial pulse feels very strong and forceful, followed by a quick collapse or sudden disappearance.

Aortic Regurgitation

The backward leaking of blood from the aorta into the left ventricle caused by failure of the aortic valve to close tightly, leading to fluid volume overload and left ventricular dilation.

Mitral Stenosis

Narrowing, thickening, and rigidity of the mitral valve that impedes blood flow from the left atrium to the left ventricle, causing pulmonary congestion, crackles, and right-sided heart failure.

Mitral Regurgitation

Incomplete closure of the mitral valve during ventricular systole, resulting in backward flow of blood into the left atrium, pulmonary congestion, diminished $S_1$, and decreased cardiac output.

Mitral Valve Prolapse

A condition where the mitral valve leaflets become enlarged and floppy, causing them to bulge backward into the left atrium during ventricular systole, frequently marked by a systolic click.

Arteriosclerosis

The loss of arterial elasticity and hardening of the arteries that accompanies the aging process, often involving cytoplasmic calcium accumulation.

Atherosclerosis

A condition in which the lumen of arteries is partially obstructed by fatty plaque deposits (atheromas) composed of cholesterol and smooth muscle cells.

Angina

Chest discomfort caused by temporary myocardial ischemia without permanent myocardial cell death.

Myocardial Infarction

Necrosis of heart muscle tissue resulting from prolonged coronary artery occlusion and ischemia.

Transmural Infarction

A Q-wave myocardial infarction in which tissue necrosis extends through the full thickness of the myocardial wall.

Subendocardial Infarction

A non-Q wave myocardial infarction in which necrotic tissue damage is limited to only part of the thickness of the myocardial wall.

Troponin

A cardiac biomarker that rises in the bloodstream when myocardial cells are injured, serving as a primary laboratory indicator for diagnosing an acute myocardial infarction.

Intermittent Claudication

Pain and cramping in leg muscles during activity, caused by inadequate arterial blood flow and oxygen delivery in peripheral artery disease.

Critical Limb Ischemia

A severe stage of peripheral artery disease in which chronic arterial blood flow to the extremity is so compromised that tissue viability is threatened.

Thrombus

A stationary blood clot that forms and stays in one place inside a blood vessel or the heart.

Phlebothrombosis

The development or formation of a clot inside a vein without accompanying vein inflammation.

Thrombophlebitis

Inflammation of a vein wall associated with the formation of a thrombus (blood clot).

Embolus

A moving clot or other foreign material traveling through the bloodstream that can lodge in a vessel and obstruct blood flow.

Plethysmography

A noninvasive diagnostic test used to evaluate peripheral vascular circulation by detecting changes in blood volume within an extremity.