ch27:patho Disorders of Cardiac Function, Heart Failure, and Circulatory Shock

Comprehensive vocabulary flashcards covering pathophysiology concepts including pericardial disorders, acute coronary syndromes, valvular heart disease, heart failure subtypes, congenital shunts, and mechanisms of circulatory shock.

Pericardium

A sac consisting of visceral and parietal layers surrounding a potential space containing about $50\,mL$ of lubricating fluid, which stabilizes the heart, limits overfilling, and acts as a barrier to infection.

Acute Pericarditis

Pericardial inflammation characterized by sharp, pleuritic chest pain that worsens with inspiration or lying flat and improves sitting up and leaning forward, accompanied by a friction rub and diffuse ST elevation with PR depression on ECG.

Cardiac Tamponade

A life-threatening clinical emergency caused by fluid accumulation in the pericardial sac that restricts ventricular diastolic filling, severely reducing stroke volume and cardiac output.

Beck Triad

The clinical presentation of cardiac tamponade consisting of hypotension, jugular venous distention (JVD), and muffled heart sounds.

Pulsus Paradoxus

An exaggerated fall in systolic blood pressure during inspiration caused by right ventricular overfilling in a non-expandable pericardial space, which compresses the left ventricle and reduces stroke volume.

Constrictive Pericarditis

A chronic condition where a fibrotic, rigid pericardium impairs diastolic filling, leading to systemic venous congestion, Kussmaul sign, ascites, and peripheral edema.

Myocardial Ischemia

A condition occurring when myocardial oxygen supply fails to meet oxygen demand, clinically characterized by chest pressure, heaviness, squeezing, or angina.

Vulnerable Plaque

An unstable atherosclerotic lesion with a thin fibrous cap overlying a lipid-rich inflammatory core, susceptible to rupture and acute thrombosis.

Stable Angina

Predictable, brief chest pain caused by fixed coronary artery stenosis during exertion or stress, which is relieved by rest or nitroglycerin without causing myocardial necrosis.

Acute Coronary Syndrome (ACS)

A spectrum of unstable ischemic heart conditions resulting from plaque disruption and acute thrombus formation, including unstable angina, NSTEMI, and STEMI.

High-Sensitivity Troponin

The preferred cardiac biomarker (I or T) used to detect acute myocardial injury; serial measurements showing a rise or fall are required to diagnose myocardial infarction.

Widow-Maker

An informal term for a critical proximal Left Anterior Descending (LAD) coronary artery occlusion, which threatens a large area of the left ventricle and carries high risk for cardiogenic shock and sudden death.

STEMI (ST-Elevation Myocardial Infarction)

A cardiac emergency resulting from complete and sustained coronary occlusion, showing transmural injury, ST elevation in contiguous ECG leads, and elevated troponin levels requiring immediate reperfusion.

NSTEMI

Non-ST-elevation myocardial infarction resulting from subtotal or intermittent coronary occlusion, characterized by subendocardial injury, troponin elevation, and absence of persistent ST elevation.

Unstable Angina

An acute coronary syndrome presenting with new-onset, worsening, or rest chest pain caused by plaque disruption without cardiac biomarker (troponin) elevation.

Door-to-Balloon Time

The target time window of $60\text{--}90\text{ minutes}$ for emergency reperfusion therapy (PCI) to restore coronary flow and limit expanding myocardial necrosis.

Dressler Syndrome

A late, immune-mediated pericarditis that develops weeks following a myocardial infarction.

Dilated Cardiomyopathy

A structural cardiac condition characterized by ventricular dilation, impaired systolic contractility, reduced ejection fraction, and an elevated risk for volume congestion and mural thrombi.

Hypertrophic Cardiomyopathy (HCM)

An inherited cardiac disorder marked by disproportionate myocardial thickening, reduced left ventricular cavity size, potential dynamic outflow tract obstruction, and risk of exertional syncope or sudden cardiac death.

Infective Endocarditis

Microbial infection of the endocardium and heart valves characterized by friable vegetations, valve destruction, new or changing heart murmurs, and systemic embolization.

Myocarditis

An inflammatory disease of the heart muscle, often viral or immune-mediated, that causes myocyte injury, chest pain, dysrhythmias, and potential progression to dilated cardiomyopathy.

Rheumatic Fever

An autoimmune cross-reaction triggered by Group A streptococcal pharyngitis that causes carditis, valve inflammation, and progressive fibrous fusion of heart valves.

Valvular Stenosis

A mechanical valve failure where the leaflets cannot open fully, resulting in obstructed forward blood flow and pressure overload in the chamber proximal to the valve.

Valvular Regurgitation

A structural failure of a valve to close tightly, permitting backward blood flow and causing volume overload and progressive chamber dilation.

HFrEF

Heart Failure with Reduced Ejection Fraction (systolic failure), characterized by impaired ventricular contraction, left ventricular dilation, and decreased ejection fraction.

HFpEF

Heart Failure with Preserved Ejection Fraction (diastolic failure), characterized by stiff, non-compliant ventricles that impair diastolic relaxation and raise filling pressures despite a normal ejection fraction.

Left-Sided Heart Failure

Failure of the left ventricle causing blood to back up into the pulmonary vascular bed, leading to pulmonary congestion, dyspnea, orthopnea, paroxysmal nocturnal dyspnea (PND), diffuse crackles, and hypoxemia.

Right-Sided Heart Failure

Failure of the right ventricle leading to systemic venous congestion, jugular venous distention (JVD), peripheral edema, hepatomegaly, ascites, and weight gain.

Acute Pulmonary Edema

A severe gas-exchange emergency caused by rapidly rising pulmonary capillary pressures, driving fluid into the alveoli and causing severe dyspnea, orthopnea, crackles, and pink frothy sputum.

Left-to-Right Shunt

A congenital heart defect where oxygenated systemic arterial blood flows back into the pulmonary circulation, increasing pulmonary blood flow and causing volume overload.

Right-to-Left Shunt

A congenital heart defect that allows deoxygenated venous blood to enter systemic circulation directly, causing persistent cyanosis, digital clubbing, and secondary polycythemia.

Circulatory Shock

A state of acute systemic failure of tissue perfusion where cellular oxygen delivery fails to meet metabolic demand, prompting anaerobic metabolism and lactate accumulation.

Cardiogenic Shock

A form of low-flow shock caused by primary myocardial pump failure despite adequate intravascular volume, presenting with decreased cardiac output, elevated filling pressures, cool clammy skin, and pulmonary congestion.

Hypovolemic Shock

A type of shock resulting from significant loss of circulating intravascular volume, causing low ventricular preload, flat neck veins, cool skin, and low cardiac output.

Distributive Shock

A class of shock characterized by widespread vasodilation and expansion of the vascular space, leading to relative hypovolemia despite a normal total blood volume.

Neurogenic Shock

A subtype of distributive shock caused by the sudden loss of sympathetic vascular tone, resulting in severe vasodilation, hypotension, and bradycardia.