Valvular Heart Disease - Detailed Review

1. AORTIC STENOSIS (AS)

Etiology

• Calcific/degenerative (most common in adults >70 yrs): same risk factors as atherosclerosis - macrophages, T-lymphocytes, lipid/calcium deposits, fibrosis
• Bicuspid aortic valve (congenital): accounts for ~50% of surgical cases; presents 1-2 decades earlier (4th-6th decade); turbulent flow leads to fibrosis and calcification
• Rheumatic: uncommon in developed countries; commissural fusion after streptococcal infection

Pathophysiology

• Normal aortic valve area (AVA): 3.0-4.0 cm²
• Symptoms appear when narrowed to <¼ normal (~0.75 cm²)
• Progressive LV pressure overload → concentric LV hypertrophy → diastolic dysfunction → increased LV filling pressure
• Myocardial O₂ demand increases → angina even without CAD
• Valve area narrows ~0.12 cm²/year

Grading

Classic Triad of Symptoms (SAD)

1. Syncope - especially exertional; may be arrhythmia-induced at rest
2. Angina - ~5-year survival after onset; O₂ demand/supply mismatch
3. Dyspnea/HF - worst prognosis; ~2-year survival after onset

Physical Examination

• Harsh, late-peaking systolic ejection murmur at right 2nd intercostal space, radiating to carotids ("diamond-shaped" crescendo-decrescendo)
• Pulsus parvus et tardus - slow, delayed carotid upstroke (may be absent in elderly due to arterial stiffening)
• Diminished or absent A2 (severe calcification)
• S4 gallop from stiff, hypertrophied LV
• Narrow pulse pressure

Diagnosis

• Echocardiography (gold standard): calcified valve, restricted leaflet motion
  • High flow, high gradient: mean gradient ≥40 mmHg, peak velocity ≥4 m/s, LV stroke volume index ≥35 mL/m²
  • Low flow, low gradient AS (>40% of older patients): gradients appear lower despite severe disease
• Echo monitoring: mild AS every 3-5 years; moderate every 1-2 years; severe every year
• Do NOT perform exercise testing in symptomatic severe AS
• Cardiac angiography before AVR if CAD suspected

Management

• Medical: No medication slows progression (statins ineffective); manage risk factors
• Surgical AVR: Standard for eligible patients
  • Preferred for age <65 years (mechanical) or 65-80 years (tissue, shared decision)
• TAVR (Transcatheter AVR): For high surgical risk; now extended to intermediate/low risk

2. AORTIC REGURGITATION (AR)

Etiology

• Chronic: Bicuspid AV, calcification, connective tissue disorders (Marfan, Ehlers-Danlos), rheumatic heart disease, ankylosing spondylitis
• Aortic root disease: Hypertension (annular dilation), aortic dissection, syphilis, giant cell arteritis
• Acute: Infective endocarditis, aortic dissection, trauma

Pathophysiology

• Volume overload of LV → eccentric LV hypertrophy (LV dilates and hypertrophies)
• LV compensates by increasing stroke volume (wide pulse pressure)
• In chronic AR: compensated for years; eventually LV systolic dysfunction
• Acute AR: abrupt volume overload - LV cannot compensate → acute pulmonary edema, cardiogenic shock

Symptoms

• Chronic: long asymptomatic phase, then dyspnea on exertion, orthopnea, PND, palpitations (forceful heartbeat)
• Acute: sudden severe dyspnea, cardiogenic shock

Physical Examination - "Peripheral Signs"

• High-pitched early diastolic blowing murmur at left lower sternal border (valvular) or upper right sternal border (root disease)
• Bounding/water-hammer pulse (Corrigan's pulse)
• Wide pulse pressure (e.g., 160/60 mmHg)
• Austin Flint murmur: mid-diastolic rumble at apex (regurgitant jet impinges on mitral valve)
• de Musset's sign: head bobbing
• Quincke's sign: capillary pulsations in fingernail bed
• Duroziez's sign: to-and-fro femoral bruit
• Hill's sign: popliteal BP >20 mmHg above brachial

Diagnosis

• Echocardiography: quantify regurgitant jet on Doppler
• Indications for surgery: chronic severe AR with LV systolic dimension >4.5 cm or LVEF <50%, even if asymptomatic

Management

• Asymptomatic with normal LV function: Watch and wait; vasodilators (nifedipine, ACE inhibitor) for hypertension
• Symptomatic or LV dysfunction: Surgical AVR (TAVR being studied for AR)
• Acute severe AR: Urgent/emergency surgery; temporizing with vasodilators (nitroprusside); IABP is contraindicated

3. MITRAL STENOSIS (MS)

Etiology

• Rheumatic heart disease (by far most common) - streptococcal pharyngitis triggers immune-mediated valve damage; leaflet thickening, commissural fusion, chordal shortening/fusion
• Rare: mitral annular calcification (MAC, usually mild MS), congenital, carcinoid, SLE (Libman-Sacks)

Pathophysiology

• Normal mitral valve area (MVA): 4-6 cm²
• Symptoms at MVA <2 cm² (moderate); severe <1.0 cm²
• Obstruction → ↑ left atrial (LA) pressure → LA enlargement → pulmonary hypertension → RV overload
• LA enlargement → atrial fibrillation (very common) → risk of LA thrombus → systemic embolism/stroke

Classic Symptoms

• Dyspnea on exertion (most common early symptom)
• Orthopnea, PND, hemoptysis (pink frothy sputum or frank hemoptysis)
• Palpitations (AF)
• Systemic embolism (stroke)
• Hoarseness (Ortner's syndrome - enlarged LA compresses left recurrent laryngeal nerve)
• RHF symptoms (when pulmonary hypertension develops)

Physical Examination

• Loud S1 (increased excursion of leaflets snapping shut)
• Opening snap (OS) after S2 - high-pitched; shorter S2-OS interval = more severe MS
• Low-pitched mid-diastolic rumbling murmur at apex, best heard with bell in left lateral decubitus; pre-systolic accentuation (if in sinus rhythm)
• Malar flush (mitral facies) in severe cases
• Signs of pulmonary hypertension: loud P2, right parasternal heave

Diagnosis

• Echocardiography (gold standard): "hockey stick" deformity of anterior mitral leaflet; doming; fusion; MVA by planimetry and pressure half-time
• Wilkins score (1-16): assesses suitability for balloon valvotomy (score ≤8 = favorable)
• CXR: LA enlargement (double density, elevated left main bronchus), pulmonary vascular congestion, Kerley B lines

Management

• Medical: Diuretics (symptom relief), beta-blockers or rate-controlling agents for AF; anticoagulation mandatory with AF (warfarin/VKA preferred; NOACs not approved for rheumatic AF)
• Percutaneous Mitral Balloon Valvotomy (PMBV/PTMC): Preferred intervention if anatomy favorable (Wilkins ≤8, no significant MR, no LA thrombus)
  • Success rates <50% in older patients; complications: tamponade ~5%, thromboembolism ~3%, death ~3%
• Mitral Valve Replacement (MVR): For unfavorable anatomy (calcified, thickened valves) or failed PTMC; perioperative mortality ≥10% in elderly
• Rheumatic fever prophylaxis: Penicillin for secondary prevention

4. MITRAL REGURGITATION (MR)

Classification

• Primary (organic) MR: Intrinsic valve leaflet/chordal pathology
• Secondary (functional) MR: Structurally normal valve displaced by LV remodeling or ischemia

Etiology

Pathophysiology

• Regurgitant volume → LA and LV volume overload
• Acute MR: LA cannot accommodate sudden volume load → ↑ LA pressure → pulmonary edema
• Chronic MR: LA and LV dilate progressively (eccentric hypertrophy) → compensated for years → eventual LV dysfunction

Symptoms

• Chronic compensated: often asymptomatic for years
• Decompensated: dyspnea, fatigue, exercise intolerance, HF symptoms
• Acute: sudden-onset severe pulmonary edema (chordal rupture, endocarditis, papillary muscle rupture post-MI)

Physical Examination

• Holosystolic/pansystolic murmur at apex radiating to axilla (loudest in mitral area)
• Soft S1 (incomplete valve closure)
• S3 gallop (volume overload)
• Displaced, hyperdynamic apical impulse (LV enlargement)
• MVP: mid-systolic click followed by late systolic murmur; click moves earlier with standing (decreased preload)

Diagnosis

• Echocardiography: color Doppler shows regurgitant jet; quantify regurgitant fraction/EROA
• Indications for surgery:
  • Symptomatic severe MR
  • Asymptomatic severe MR with LVEF 30-60% or LVESD >40 mm

Management

• Primary MR:
  • Mitral valve repair preferred over replacement (better outcomes, durability)
  • Vasodilators in acute setting (nitroprusside, nitroglycerin)
  • Transcatheter MitraClip (edge-to-edge repair): for high-surgical-risk patients with primary MR; also for secondary MR in HF (COAPT trial)
• Secondary MR: Treat underlying HF (GDMT), CRT if indicated; surgery if severe and undergoing coronary revascularization

5. MITRAL VALVE PROLAPSE (MVP)

Definition

Epidemiology

• Most common valvular abnormality: prevalence ~2-3% of general population
• More common in young, thin women

Pathophysiology

• Myxomatous degeneration of leaflets (acid mucopolysaccharide accumulation) → leaflet redundancy/elongation → prolapse
• May cause MR due to incomplete coaptation

Symptoms

• Most asymptomatic
• Atypical chest pain, palpitations, anxiety
• Rare: sudden cardiac death (especially with severe MR, arrhythmias)

Physical Examination

• Mid-systolic click (most characteristic) ± late systolic murmur
• Click moves earlier with maneuvers that decrease preload (standing, Valsalva)
• Click moves later with maneuvers that increase preload (squatting, leg raise)

Management

• Reassurance for most; beta-blockers for symptoms; MVP repair/replacement for severe MR

6. TRICUSPID STENOSIS (TS)

Etiology

• Almost always rheumatic (rarely isolated; usually with MS)
• Carcinoid syndrome (right-sided valves affected by serotonin)
• Congenital

Pathophysiology

• Obstruction to right ventricular filling → elevated right atrial pressure → systemic venous hypertension

Clinical Features

• Fatigue (reduced CO), peripheral edema, ascites, hepatomegaly
• Elevated JVP with prominent a wave
• Mid-diastolic murmur at left lower sternal border, increases with inspiration (Carvallo's sign - increases with inspiration, differentiates from mitral murmur)

Management

• Diuretics; valve repair or replacement (often done at time of mitral surgery)

7. TRICUSPID REGURGITATION (TR)

Etiology

• Functional/secondary (most common): RV dilation from pulmonary hypertension, left-sided HF, RV infarction, cardiomyopathy
• Primary: Rheumatic, endocarditis (especially IV drug users), carcinoid, Ebstein's anomaly, trauma

Clinical Features

• Peripheral edema, ascites, hepatomegaly, jaundice (congestive hepatopathy)
• Elevated JVP with prominent v wave and rapid y descent
• Holosystolic murmur at left lower sternal border, increases with inspiration
• Pulsatile liver, prominent neck vein pulsations

Management

• Treat underlying cause (pulmonary hypertension, left-sided disease)
• Diuretics for volume overload
• Tricuspid valve repair or replacement when severe, often at time of left-sided surgery

8. PULMONARY STENOSIS (PS)

Etiology

• Usually congenital (most common congenital valvular disease)
• Carcinoid syndrome
• Rheumatic (rare)

Clinical Features

• Usually asymptomatic in mild-moderate; dyspnea/syncope with severe PS
• Systolic ejection murmur at left upper sternal border, increases with inspiration
• Wide split S2 with soft/absent P2
• RVH on ECG; post-stenotic pulmonary artery dilation on CXR

Management

• Percutaneous balloon valvuloplasty (treatment of choice for isolated valvular PS)
• Surgery reserved for severe subvalvular/supravalvular disease

9. PULMONARY REGURGITATION (PR)

Etiology

• Functional: Pulmonary hypertension (most common), dilated pulmonary annulus
• Iatrogenic: Post-repair of tetralogy of Fallot (very common)
• Infective endocarditis, carcinoid

Clinical Features

• Often asymptomatic
• Graham Steell murmur: High-pitched early diastolic murmur at left upper sternal border due to pulmonary hypertension
• Signs of RV volume overload in severe cases

Management

• Treat underlying pulmonary hypertension
• Pulmonary valve replacement if severe (especially post-TOF repair with RV dilation)

Summary Comparison Table

General Principles

1. Antibiotic prophylaxis for infective endocarditis is now only recommended for high-risk patients (prosthetic valves, prior IE, certain congenital defects, cardiac transplant with valvulopathy) - not for all VHD
2. Echocardiography is the primary diagnostic and monitoring tool for all valvular lesions
3. Timing of intervention is critical - act before irreversible LV/RV dysfunction develops
4. Rheumatic heart disease remains the dominant cause of VHD worldwide (especially MS, TR, TS); degenerative/calcific disease predominates in developed countries
5. Pregnancy significantly worsens MS (increased heart rate and blood volume) and moderate-severe AS; careful management required

• Textbook of Family Medicine 9e, pp. 656-680
• Braunwald's Heart Disease, 12e, Chapters 72-78