Chapter 5 Word List - Cardiology Terms

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Cardiomyopathy

• Definition: Disease of the heart muscle that impairs the heart’s ability to pump blood effectively.
• Key concepts:
  • Types commonly discussed: dilated, hypertrophic, restrictive (and ARVC as a related muscular cardiomyopathy).
  • Resulting dysfunction can lead to heart failure, arrhythmias, and reduced cardiac output.
• Clinical relevance:
  • May present with dyspnea, fatigue, edema, or decreased exercise tolerance.
  • Diagnostic workup typically includes echocardiography, ECG, and sometimes cardiac MRI or biopsy.
• Significance in exams:
  • Understanding how myocardial structure changes affect function and rhythm can explain symptoms and treatment choices.
• Basic pathophysiology relation:
  • Change in myocardial contractility alters stroke volume (SV) and cardiac output (CO).
• Example/metaphor:
  • Think of the heart as a pump; cardiomyopathy is a problem with the pump walls that reduces pumping efficiency.
• Related formulas:
  • Cardiac output: CO = SV \times HR
  • Ejection fraction (EF) as a key measure of pumping efficiency: EF = \frac{SV}{EDV}
• Diagnostic anchors:
  • Echocardiography for chamber sizes and wall motion
  • ECG for rhythm abnormalities
• Treatments overview:
  • Medications to reduce symptoms and improve output (ACE inhibitors, beta-blockers, diuretics).
  • Devices (pacemakers/ICDs) for rhythm and conduction issues.
  • Lifestyle and, in advanced cases, transplant consideration.
• Practical implications:
  • Regular monitoring for progression; risk of sudden cardiac death in some forms.

Bradycardia

• Definition: Abnormally slow heart rate, typically <60 beats per minute in adults.
• Key concepts:
  • Types: sinus bradycardia, atrioventricular (AV) block (first/second/third degree).
• Clinical relevance:
  • May cause dizziness, fatigue, syncope, or exercise intolerance; can be benign in athletes.
• Diagnostic anchors:
  • 12-lead ECG to classify rhythm and conduction block; continuous monitoring if symptomatic.
• Management notes:
  • Treat underlying cause (medication reduction, thyroid treatment).
  • Acute symptomatic cases may require atropine or temporary/permanent pacing depending on severity and degree of block.
• Pathophysiology connections:
  • Slower heart rate reduces cardiac output if stroke volume cannot compensate.
• Related formulas:
  • If needed: CO = SV \times HR and observation that decreased HR can be offset by increased SV, not always sufficient.
• Practical implications:
  • In patients with conduction disease or post-heart surgery, monitor for signs of hemodynamic compromise.

Angioplasty

• Definition: A percutaneous procedure to open a narrowed or blocked coronary artery, often with balloon dilation.
• Key concepts:
  • Often performed with stent placement (drug-eluting or bare-metal).
  • Goals: restore blood flow, relieve ischemia, improve symptoms.
• Types:
  • Balloon angioplasty (PTCA) vs stenting (with or without drug-eluting coating).
• Procedural steps (high level):
  • Vascular access → catheter navigation to lesion → balloon inflation to compress plaque → stent deployment if indicated.
• Risks and complications:
  • Restenosis, vessel dissection, MI, stroke, bleeding, contrast reaction.
• Post-procedure management:
  • Antiplatelet therapy (e.g., aspirin plus another agent like clopidogrel) to prevent stent thrombosis.
• Clinical relevance:
  • Common revascularization option for stable angina or certain acute coronary syndromes.
• Related concepts:
  • Acute coronary syndrome, coronary artery disease, PCI as part of a broader revascularization strategy.

Defibrillation

• Definition: Delivery of an electrical shock to the heart to terminate certain life-threatening arrhythmias and reset rhythm.
• Key concepts:
  • Indications primarily include pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF).
  • Can be external (AED or manual defibrillator) or implantable (ICD).
• Mechanism:
  • Simultaneous depolarization of cardiac cells to halt disorganized activity and allow a normal pacemaker activity to resume.
• Management context:
  • In emergency settings, follow ACLS protocols: CPR, defibrillation, and then medication as indicated.
• Outcomes and considerations:
  • ICDs provide ongoing risk reduction for sudden cardiac death in patients with high-risk rhythm disorders.
• Practical notes:
  • Defibrillation energy levels depend on device and clinical scenario; external defibrillators deliver energy in joules per shock.

Pericardium

• Definition: The double-layered sac surrounding the heart composed of the visceral (epicardium) and parietal layers with pericardial fluid in between.
• Functions:
  • Reduces friction during cardiac cycles; contains a small amount of lubricating fluid; helps limit acute cardiac dilation.
• Common diseases:
  • Pericarditis, pericardial effusion, cardiac tamponade, constrictive pericarditis.
• Diagnostic cues:
  • Echo to assess effusion, chest imaging, ECG changes in pericarditis (diffuse ST elevation, PR depression).
• Treatments overview:
  • Pericarditis: NSAIDs, colchicine; effusion with tamponade may require pericardiocentesis; constrictive disease may need surgical intervention.
• Practical relevance:
  • Changes in pericardial pressure affect venous return and cardiac output.

Diuretic

• Definition: A drug that increases urine output to remove excess fluid from the body.
• Key classes:
  • Loop diuretics (e.g., furosemide), thiazides (e.g., hydrochlorothiazide), potassium-sparing (e.g., spironolactone).
• Indications:
  • Edema from heart failure, hypertension, certain kidney diseases, and fluid overload states.
• Mechanisms:
  • Different sites of action along nephron with varying potency and electrolyte effects.
• Monitoring and side effects:
  • Electrolyte disturbances (hypokalemia with loops/thiazides; hyperkalemia with potassium-sparing diuretics), dehydration, kidney function changes.
• Clinical relevance:
  • Often part of heart failure management to relieve congestion and optimize hemodynamics.

Hemostasis

• Definition: The physiological process that stops bleeding and maintains blood in a fluid, clot-free state within vessels after injury.
• Phases:
  • Vasoconstriction, platelet plug formation, coagulation cascade (intrinsic and extrinsic pathways) leading to fibrin clot.
• Key components:
  • Platelets, coagulation factors (II, VII, IX, X, etc.), fibrin.
• Regulation:
  • Balance with fibrinolysis; natural anticoagulants prevent excessive clotting.
• Clinical relevance:
  • Abnormal hemostasis leads to excessive bleeding or clotting disorders; monitoring tests like PT/INR and aPTT provide insight.
• Diagnostics and tests:
  • PT/INR, aPTT, platelet count, bleeding time in certain contexts.
• Implications:
  • Used to guide anticoagulant therapy and evaluate surgical bleeding risk.

Hemoglobin

• Definition: The oxygen-carrying protein within red blood cells.
• Function:
  • Binds and transports oxygen from lungs to tissues; returns carbon dioxide for elimination.
• Normal ranges (approximately):
  • Men: Hb_{men} \approx 13.8 - 17.2\,\text{g/dL}
  • Women: Hb_{women} \approx 12.1 - 15.1\,\text{g/dL}
• Role in disease:
  • Low Hb defines anemia; high Hb can occur in certain conditions or polycythemia.
• Diagnostic implications:
  • CBC with Hb level helps assess oxygen-carrying capacity and guides treatment for fatigue, dyspnea, and related symptoms.
• Related concept:
  • Oxygen content in blood can be approximated by: CaO2 = (Hb \times 1.34 \times SaO2) + (0.003 \times PaO_2)
• Treatment considerations:
  • Address underlying cause of anemia (iron deficiency, B12/folate deficiency, chronic disease).

Embolism

• Definition: Obstruction of a blood vessel by material that travels through the bloodstream (embolus).
• Types:
  • Arterial embolism, pulmonary embolism, fat embolism, air embolism, tumor emboli.
• Common sources:
  • Thrombus (most common), fat from broken bone, air from procedures, septic emboli.
• Clinical consequences:
  • Ischemia or infarction in affected tissues; pulmonary embolism causes hypoxemia and hemodynamic strain.
• Diagnosis and treatment:
  • Imaging (CT angiography for pulmonary embolism, Doppler for DVT), anticoagulation, and sometimes thrombolysis or surgical removal.
• Relationship to thrombus:
  • Embolus often originates from a thrombus that detaches and travels, whereas a thrombus forms in situ.

Atherectomy

• Definition: Catheter-based procedure that mechanically removes atherosclerotic plaque from an artery.
• Techniques:
  • Directional atherectomy, rotational atherectomy (rotablator), orbital atherectomy.
• Indications:
  • Peripheral artery disease (PAD) and some coronary disease cases where plaque removal is favored.
• How it complements angioplasty:
  • Plaque removal followed by angioplasty/stent when needed to improve lumen size.
• Risks:
  • Vessel injury, embolization of debris, restenosis, distal ischemia.
• Clinical relevance:
  • An alternative or adjunct to stenting in selected lesions; may reduce plaque burden more physically than angioplasty alone.

Sepsis

• Definition: Life-threatening organ dysfunction caused by a dysregulated host response to infection.
• Key concepts:
  • Sepsis-3 defines organ dysfunction (SOFA) and a systemic inflammatory response (SIRS is older terminology).
• Clinical features:
  • Fever or hypothermia, tachycardia, tachypnea, altered mental status, hypotension in septic shock.
• Diagnosis:
  • Clinical assessment plus laboratory and imaging studies to identify infection source and organ dysfunction.
• Management principles:
  • Early broad-spectrum antibiotics, fluid resuscitation, vasopressors for hypotension, source control, and supportive care.
• Practical implications:
  • Delays in antibiotics worsen outcomes; sepsis requires rapid recognition and treatment.

Endocarditis

• Definition: Infection and inflammation of the endocardial surfaces, typically the heart valves.
• Risk factors:
  • Prosthetic heart valves, rheumatic heart disease, congenital heart disease, IV drug use, recent invasive procedures.
• Clinical presentation:
  • Fever, new or changing heart murmur, fatigue, night sweats, petechiae, signs of embolic phenomena.
• Diagnostic approach:
  • Blood cultures, echocardiography (transesophageal often preferred), inflammatory markers.
• Treatment:
  • Prolonged course of intravenous antibiotics; surgery may be needed for valve repair/replacement or to manage complications.
• Significance:
  • Early detection and treatment are crucial to prevent embolic events and heart damage.

Arrhythmia

• Definition: Any abnormality in heart rhythm, rate, or sequence of electrical activation.
• Examples:
  • Atrial fibrillation, atrial flutter, ventricular tachycardia, bradyarrhythmias, premature beats.
• Clinical relevance:
  • Can cause palpitations, dizziness, syncope, or stroke risk (especially with AF).
• Diagnostic approach:
  • ECG is primary; Holter or event monitors used for intermittent issues.
• Management principles:
  • Depends on type: rate control, rhythm control, and anticoagulation where stroke risk is present (e.g., AF).
• Connection to other topics:
  • Defibrillation and pacemaker therapies address rhythm disturbances; anticoagulants may be used to prevent thromboembolism in AF.

Anticoagulant

• Definition: Drugs that reduce blood clotting to prevent thrombus formation or growth.
• Common agents:
  • Heparin (unfractionated), low-molecular-weight heparin, warfarin, and direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, dabigatran.
• Indications:
  • Atrial fibrillation, venous thromboembolism (DVT/PE), mechanical heart valves, after certain procedures.
• Monitoring and dosing:
  • Warfarin requires INR monitoring; heparin monitoring uses aPTT; DOACs have fixed dosing with fewer lab tests.
• Risks and management:
  • Bleeding risk; reversal strategies depend on agent (e.g., vitamin K for warfarin, specific reversal agents for DOACs).
• Practical considerations:
  • Drug interactions (e.g., with foods high in vitamin K, certain antibiotics) and patient-specific bleeding risk evaluation.

Anemia

• Definition: Decrease in total circulating red blood cells or hemoglobin, reducing oxygen-carrying capacity.
• Common causes:
  • Iron deficiency, vitamin B12 or folate deficiency, chronic disease, hemolysis, acute blood loss.
• Symptoms:
  • Fatigue, pallor, shortness of breath, dizziness, tachycardia.
• Diagnostic approach:
  • CBC showing low Hb, low hematocrit; mean corpuscular volume (MCV) helps classify; ferritin and B12/folate levels as needed.
• Treatment considerations:
  • Address underlying cause; iron supplementation for iron deficiency; B12/folate supplementation; transfusion in severe cases.
• Significance:
  • Impacts exercise tolerance and overall energy; may be a marker of chronic disease or nutritional deficiency.

Thrombolytic

• Definition: Drugs that dissolve existing clots by activating plasminogen to plasmin, which degrades fibrin.
• Common agents:
  • Tissue plasminogen activator (tPA), streptokinase, urokinase.
• Indications:
  • Acute myocardial infarction, acute ischemic stroke within therapeutic window, massive pulmonary embolism with hemodynamic compromise.
• Contraindications and risks:
  • Active bleeding, recent surgery, high bleeding risk; major risk is intracranial hemorrhage.
• Mechanism in brief:
  • Converts plasminogen to plasmin; plasmin digests fibrin clots, restoring blood flow.
• Clinical considerations:
  • Timely decision-making is critical; requires imaging confirmation and risk-benefit assessment.

Angina

• Definition: Chest pain or discomfort caused by myocardial ischemia due to insufficient blood flow to the heart muscle.
• Types:
  • Stable angina, unstable angina, and variant (Prinzmetal) angina.
    -Typical features:
  • Pressure-like pain or tightness in the chest, may radiate to shoulder, arm, jaw; provoked by exertion or stress and relieved by rest or nitroglycerin.
• Management overview:
  • Acute relief with nitrates; long-term control with antianginal agents (beta-blockers, calcium channel blockers), antiplatelet therapy, lipid management, and lifestyle changes; revascularization for eligible patients.
• Significance:
  • Indicates myocardial ischemia; risk stratification guides further testing and possible interventions.

Thrombus

• Definition: A static blood clot formed within a vessel or the heart due to activation of the coagulation cascade.
• Distinction from embolus:
  • A thrombus forms in place; an embolus travels after detaching.
• Common sites and risks:
  • Deep vein thrombosis (DVT), pulmonary embolism (PE), coronary or cerebral vessels depending on location.
• Contributing factors (Virchow’s triad):
  • Stasis, endothelial injury, hypercoagulability.
• Management themes:
  • Anticoagulation to prevent propagation, thrombolysis or surgical removal in select cases, compression therapy for DVT.
• Clinical relevance:
  • Thrombus formation is a central concept in vascular medicine and many cardiovascular conditions.

Tachycardia

• Definition: Abnormally fast heart rate, typically >100 beats per minute at rest in adults.
• Types:
  • Sinus tachycardia, supraventricular tachycardia (SVT), ventricular tachycardia (VT).
• Causes:
  • Physiologic (fever, exercise, pain), pathologic (anemia, dehydration, heart failure, drugs, thyroid disease).
• Clinical impact:
  • Can reduce diastolic filling time and cardiac output; may trigger symptoms like dizziness or palpitations.
• Management principles:
  • Treat underlying cause; rate control with medications (beta-blockers, calcium channel blockers) or rhythm control strategies; assess for instability requiring urgent intervention.
• Connection to other topics:
  • Tachyarrhythmias can be managed with defibrillation or pacing in acute settings; anticoagulation decisions may be guided by rhythm type (e.g., AF).

Phlebitis

• Definition: Inflammation of a vein, which can be accompanied by thrombosis (thrombophlebitis) or infection.
• Common contexts:
  • IV catheter sites, superficial veins, or spontaneous vein inflammation.
• Signs and symptoms:
  • Redness, warmth, tenderness along the course of the vein; possible swelling.
• Management:
  • Local measures (warm compresses, NSAIDs); treat infection if indicated; anticoagulation if thrombophlebitis with significant symptoms or progression.
• Practical considerations:
  • Early detection reduces risk of extension to deeper venous systems and reduces discomfort for the patient.