Cardiovascular Disorders

Valvular Heart Disease

Clinical overview and exam mastery guide covering aortic and mitral valve disease, drug support strategies, intervention timing, and prosthetic valve anticoagulation.

Core Lesions
Stenosis or regurgitation
High-Yield Valves
Aortic and mitral
Severe AS Clue
SAD triad
Mechanical Valve
Warfarin required

Valve Lesion Pattern

Stenosis Narrow orifice -> pressure overload Regurgitation Backflow -> volume overload Definitive strategy in severe disease Surgical replacement/repair or transcatheter intervention (selected patients)

Medical therapy supports symptoms; intervention is definitive in advanced lesions.

1. What Is Valvular Heart Disease?

Valvular heart disease (VHD) is dysfunction of one or more cardiac valves resulting in stenosis (narrowing) or regurgitation (backflow). The most tested lesions involve aortic and mitral valves.

Aortic valve Mitral valve Stenosis Regurgitation

2. Major Valve Disorders

Aortic Lesions

  • Aortic stenosis (AS)
  • Aortic regurgitation (AR)

Mitral Lesions

  • Mitral regurgitation (MR)
  • Mitral stenosis (MS)

3. Aortic Stenosis (AS)

Pathophysiology

  • Calcific degeneration or congenital bicuspid valve
  • LV outflow obstruction and increased afterload
  • Left ventricular hypertrophy

Classic Symptoms

  • Syncope
  • Angina
  • Dyspnea (heart failure)

SAD is the classic severe AS triad.

Definitive treatment is valve replacement (surgical AVR or TAVR in selected patients). Drugs are supportive and do not reverse severe AS.
Avoid aggressive vasodilation in severe aortic stenosis.

4. Aortic Regurgitation (AR)

Incomplete valve closure causes diastolic backflow into the LV, leading to chronic volume overload and LV dilation.

Therapy MOA Side Effects Contraindications
ACE inhibitors Reduce angiotensin II and systemic vascular resistance (afterload reduction) Cough, hyperkalemia, renal impairment Pregnancy, bilateral renal artery stenosis
Definitive treatment is valve replacement when symptomatic or with LV dysfunction.

5. Mitral Regurgitation (MR)

Backflow into the left atrium causes volume overload, left atrial enlargement, and increased risk of atrial fibrillation.

Management Priorities

  • Valve repair is preferred for suitable symptomatic patients
  • Afterload reduction support (e.g., ACE inhibitors)
  • Diuretics for congestion symptom control

Loop Diuretics

  • MOA: inhibit Na-K-2Cl transporter in loop of Henle
  • Effect: reduce volume overload symptoms
  • Side effects: hypokalemia, dehydration, hypotension
  • Role: symptom control only (not definitive lesion correction)

6. Mitral Stenosis (MS)

Often rheumatic in origin. Obstructed LV filling raises left atrial pressure, causes pulmonary congestion, and increases AF/thromboembolic risk.

Beta Blockers

  • MOA: slow heart rate and increase diastolic filling time
  • Side effects: bradycardia, fatigue

Anticoagulation (If AF)

  • Warfarin preferred in rheumatic MS with AF
  • Goal: reduce systemic embolic stroke risk

7. Prosthetic Valves

Mechanical Valves

  • Durable option
  • Requires lifelong warfarin anticoagulation

Bioprosthetic Valves

  • Less durable
  • Shorter anticoagulation duration in many cases
Drug MOA Monitoring Contraindications / Traps
Warfarin (mechanical valve) Inhibits vitamin K-dependent factors II, VII, IX, X INR typically 2.5 to 3.5 (valve dependent) Pregnancy contraindication; DOACs contraindicated in mechanical valves

8. Infective Endocarditis Prophylaxis

Who Needs Prophylaxis?

  • Prosthetic valve patients
  • Prior infective endocarditis
  • Certain congenital heart diseases

Procedure Context

  • Before high-risk dental procedures with gingival manipulation

Amoxicillin (First-line)

  • MOA: beta-lactam, inhibits bacterial cell wall synthesis
  • Use: prophylaxis in high-risk groups only
  • Major side effects: hypersensitivity rash, GI upset
  • Contraindication: serious beta-lactam allergy

Management Recap Drill

Aortic stenosis: valve replacement is definitive.
Aortic regurgitation: afterload reduction support, surgery if symptomatic/LV dysfunction.
Mitral regurgitation: repair preferred; ACE inhibitor plus diuretic support.
Mitral stenosis: rate control and anticoagulate if AF present.
Mechanical valve: warfarin only (no DOACs).

Visual Algorithm Placeholder

[Insert Valvular Disease Diagnostic and Treatment Flowchart Here During UI Integration]

Guideline References (Management)

ACC/AHA Guideline: Valvular Heart Disease

https://www.acc.org/guidelines

High-Yield Scope

  • Timing of surgery/intervention
  • TAVR candidacy principles
  • Prosthetic valve anticoagulation

9. Common Exam Traps

DOACs are contraindicated in mechanical valves.
Severe AS: avoid aggressive vasodilation.
MS with AF requires anticoagulation.
SAD describes severe AS symptom triad.
Definitive severe valve disease treatment is intervention, not medical therapy alone.

10. Quick Revision Summary

Core Memory Anchors

  • AS: pressure overload
  • AR: volume overload
  • MR: left atrial dilation and AF tendency
  • MS: often rheumatic
  • Mechanical valves: lifelong warfarin

Practice Questions Placeholder

  • Topic: Valvular Heart Disease
  • Subtopics: aortic stenosis, aortic regurgitation, mitral regurgitation, mitral stenosis, prosthetic valves, endocarditis prophylaxis