Courses

Valvular Disorders

Overview

1. Overview of Valvular Heart Disease

1.1 Definition

  • Valvular heart disease encompasses any disorder affecting the cardiac valves, resulting in:
    • Stenosis: Narrowing of the valve orifice, restricting forward flow.
    • Regurgitation: Incompetent or “leaky” valve, allowing reverse flow.
    • A combination of both stenosis and regurgitation in the same valve.

1.2 Epidemiology

  • Commonality:
    • Aortic stenosis is the most frequent major valve lesion, followed closely by mitral regurgitation.
    • In individuals aged 70+ years, over 10% have some form of significant valve disease, whereas <1% under 40 years are affected.
  • Etiological Trends:
    • Rheumatic fever has historically been a leading cause worldwide, particularly in low- and middle-income countries.
    • In high-income countries, age-related degeneration now accounts for the majority of cases.

1.3 Pathophysiological Consequences

  • Left-Sided Valves (aortic and mitral)
    • Untreated or severe disease can lead to left ventricular dysfunction, pulmonary arterial hypertension (PAH), or both.
  • Right-Sided Valves (tricuspid and pulmonary)
    • Less commonly involved in primary disease (information on right-sided lesions is typically covered separately), but can still be significantly impacted by congenital anomalies or secondary to left-sided failure.

1.4 Clinical Importance

  • Requires early antibiotic treatment to prevent devastating outcomes.
  • Surgical Intervention:
  • Definitive management of significant stenosis or regurgitation requires valve repair or replacement.
  • Timing of surgery is crucial:
  • Too late: risk of irreversible cardiac damage and/or PAH.
  • Too early: risk of unnecessary procedure, potential complications of prosthetic valves, and possible need for redo surgery.
  • Infective Endocarditis:
  • Can acutely damage previously normal or diseased valves, leading to rapid valvular dysfunction.
Aortic Stenosis

2. Aortic Stenosis

2.1 Definition

  • Aortic stenosis (AS) is a narrowing of the aortic valve orifice during systole, impeding blood flow from the left ventricle (LV) into the aorta.
  • The valve is typically considered severely stenotic when the valve area is <1.0 cm².

2.2 Epidemiology

  • Commonest significant valve lesion in high-income countries.
  • Prevalence rises with age:
    • ~2% in those >65 years
    • ~3% in those >75 years
    • ~4% in those >85 years
  • Bicuspid aortic valve (1–2% of the population) predisposes to earlier onset AS (often by the 5th decade).

2.3 Aetiology

  1. Degenerative (Calcific) “Wear and Tear” AS
    • Leading cause in older adults (>60 years).
    • Chronic leaflet fibrosis and calcification.
    • Accelerated in individuals with a bicuspid aortic valve.
  2. Rheumatic Heart Disease
    • Often accompanied by mitral valve involvement.
    • Fusion of aortic commissures differentiates it from simple calcific degeneration.
  3. Other Risk Factors/Associations
    • Smoking, hypercholesterolaemia, hypertension, diabetes, renal impairment.
    • Rare associations: Paget’s disease, SLE, hyperparathyroidism.

2.4 Pathogenesis

  • Calcific/Inflammatory changes of valve leaflets → restricted motion and narrowed orifice.
  • LV Outflow Obstruction → Concentric LV Hypertrophy (LVH) to compensate for increased afterload.
  • Over time, LVH compromises diastolic (and eventually systolic) function, leading to pulmonary hypertension, heart failure, and possibly microangiopathic hemolytic anemia (schistocyte formation across the calcified valve).

2.5 Clinical Features

2.5.1 Symptoms

  • Asymptomatic Phase: Can last for many years, even with moderate AS.
  • Symptom Triad (often exertional):
    1. Angina: Oxygen demand > supply in a hypertrophied LV.
    2. Syncope/Presyncope: Inability to adequately increase cardiac output on exertion.
    3. Dyspnoea (Heart Failure): Diastolic then systolic dysfunction with elevated LV end-diastolic pressures.
  • Fatigue may also occur due to reduced cardiac output.

2.5.2 Signs

  • Slow-rising, low-volume (“pulsus parvus et tardus”) carotid pulse.
  • Narrow pulse pressure (e.g., 100/80 mmHg).
  • Heaving apex beat (LVH).
  • Soft/absent A2 (aortic component of S2) if heavily calcified.
  • Ejection Systolic Murmur:
    • Crescendo-decrescendo, best heard at the aortic area (right second intercostal space), radiating to the carotids.
    • Often preceded by a systolic ejection click in earlier disease.
  • Thrill at the aortic area in severe cases (≥4/6 murmur).

2.6 Diagnosis

2.6.1 Clinical Assessment

  • Key findings on history (exertional symptoms) and exam (murmur, pulse characteristics).

2.6.2 Electrocardiogram (ECG)

  • Commonly shows Left Ventricular Hypertrophy (LVH).
  • Possible secondary repolarization changes in lateral leads.

2.6.3 Echocardiography

  • Transthoracic Echo (TTE):
    • Mainstay for diagnosing, grading severity (e.g., valve area, peak/mean gradients), and assessing LV function.
    • Identifies leaflet calcification and mobility.
  • Stress Echo (dobutamine) can help distinguish true severe AS from low-flow states when LV function is poor.

2.6.4 Cardiac Catheterisation

  • Direct measurement of LV-aortic gradient if echo is inconclusive.
  • Coronary angiography often performed to check for coexisting coronary artery disease prior to surgery.

2.7 Management

2.7.1 Medical Therapy

  • No treatment halts disease progression.
  • Symptomatic management of angina, hypertension, or heart failure must be cautious due to fixed outflow obstruction:
    • Avoid excessive preload/afterload reduction (e.g., high-dose vasodilators, aggressive diuretics).

2.7.2 Surgical Aortic Valve Replacement (SAVR)

  • Definitive therapy for severe symptomatic AS or asymptomatic severe AS with LV dysfunction.
  • Prosthetic Valve Options:
    • Mechanical: Durable, but lifelong anticoagulation is required.
    • Bioprosthetic: Lower durability (~10–15 years), but only short-term anticoagulation needed.

2.7.3 Transcatheter Aortic Valve Implantation (TAVI)

  • Less invasive alternative for high-risk or inoperable patients.
  • A bioprosthetic valve is placed via a catheter (usually transfemoral).
  • Risks: stroke, paravalvular leak, vascular complications.
  • Outcomes in suitable high-risk patients can match or exceed surgical results.

2.8 Prognosis

  • Asymptomatic: Good long-term outcome, especially if the valve area remains >1.5 cm².
  • Symptomatic Severe AS (without intervention) has a poor natural history:
    • Angina → 50% mortality at 5 years
    • Syncope → 50% mortality at 3 years
    • Heart failure → 50% mortality at 2 years
  • Timely Valve Replacement typically restores near-normal survival if performed before irreversible LV dysfunction occurs.
Aortic Regurgitation

3. Aortic Regurgitation

3.1 Definition

  • Aortic regurgitation (AR) occurs when the aortic valve is incompetent, permitting blood to leak from the aorta into the left ventricle (LV) during diastole.
  • This results in a volume overload of the LV, as it must accommodate both the normal left atrial inflow and the regurgitated flow from the aorta.

3.2 Epidemiology

  • Prevalence increases with age.
  • Approximately 10% of the general population have some degree of AR, but only ~10% of these have clinically significant disease.
  • Degenerative valve disease is the leading cause in high-income countries.

3.3 Aetiology

  1. Valve Leaflet Degeneration or Damage
    • Calcific/degenerative changes, endocarditis, bicuspid aortic valve, rheumatic heart disease, or cusp prolapse.
  2. Aortic Root Dilatation
    • May be due to aneurysm, dissection, or connective tissue diseases (e.g., Marfan’s syndrome, Ehlers–Danlos, osteogenesis imperfecta).
    • Inflammatory conditions: e.g., rheumatoid arthritis, ankylosing spondylitis, large vessel vasculitides (e.g., Takayasu arteritis).
  3. Common Pathological Processes
    • Syphilitic aneurysm (historically).
    • Aortic dissection involving the ascending aorta.

3.4 Pathogenesis

  1. Chronic AR
    • The regurgitant jet increases LV end-diastolic volume.
    • Over time, LV undergoes eccentric hypertrophy and dilatation to accommodate the extra volume while maintaining forward cardiac output.
    • Patients can remain asymptomatic for years (compensated phase).
    • Eventually, the LV decompensates → heart failure symptoms.
  2. Acute AR
    • Sudden volume overload in a previously normal LV → inadequate compensation, leading to tachycardia, acute heart failure, and pulmonary oedema.
    • Causes include infective endocarditis or acute aortic dissection involving the aortic root.

3.5 Clinical Features

3.5.1 Symptoms

  • Long latent period in chronic AR.
  • Dyspnoea, orthopnoea, and paroxysmal nocturnal dyspnoea appear when the LV fails (heart failure).
  • Angina may occur due to reduced diastolic aortic pressure (decreasing coronary perfusion pressure).

3.5.2 Signs

  1. Wide Pulse Pressure
    • Increased systolic pressure (due to elevated stroke volume).
    • Decreased diastolic pressure (due to regurgitation into the LV).
  2. “Hyperdynamic” Circulation and Eponymous Signs
    • Corrigan’s pulse (collapsing or water-hammer pulse).
    • De Musset’s sign (head nodding with each heartbeat).
    • Quincke’s sign (pulsatile nail bed capillaries).
    • Traube’s sign (“pistol shot” sounds over femoral arteries).
    • Müller’s sign (pulsating uvula).
  3. Laterally displaced apex beat (LV dilatation).
  4. Diastolic Murmur
    • Early diastolic decrescendo murmur best heard along the left sternal edge with the patient leaning forward in expiration.
    • In severe AR, it may last throughout diastole.
    • A coexistent flow murmur (ejection systolic) may be heard due to the increased stroke volume across a normal orifice.

3.6 Diagnostic Approach

  1. Clinical Assessment
    • History for exercise intolerance, breathlessness, and signs of hyperdynamic circulation.
    • Physical exam revealing diastolic murmur and wide pulse pressure findings.
  2. Echocardiography
    • Two-dimensional imaging: Evaluates the aortic root size, LV dimensions, leaflet morphology (degeneration, prolapse).
    • Doppler: Estimates regurgitant jet width, regurgitant fraction, and severity.
    • Essential for grading AR and monitoring LV function.
  3. Additional Investigations
    • Chest X-ray: May show cardiomegaly (dilated LV).
    • ECG: Possible LV hypertrophy in chronic AR.
    • Aortography or MRI: Clarifies aortic root pathology if indicated.

3.7 Management

  1. Medical Therapy
    • Afterload Reduction (e.g., ACE inhibitors, vasodilators) to decrease regurgitant flow and improve forward output; used when surgery is not yet indicated or if patient is inoperable.
    • Beta-blockers or non-dihydropyridine calcium channel blockers: Use with caution; they prolong diastole, potentially increasing the regurgitant volume.
  2. Surgical Aortic Valve Replacement
    • Definitive for severe AR once symptoms develop or LV shows significant dilatation/dysfunction.
    • Criteria often include:
      • NYHA II–IV symptoms
      • Marked LV dilatation
      • Dilated aortic root (requiring valve + root replacement)
    • Timing is crucial to avoid irreversible LV damage.
  3. Percutaneous Interventions
    • Currently, no well-established percutaneous therapy for pure AR (unlike TAVI for stenosis).

3.8 Prognosis

  • Chronic compensated AR: Long asymptomatic period, but once LV function declines, the deterioration can be rapid.
  • Acute severe AR: Poor unless emergent treatment is undertaken (e.g., surgical repair).
  • Postoperative Outcomes largely depend on preoperative LV function; a normal or only mildly dilated LV at surgery predicts better survival.
Mitral Stenosis

4. Mitral Stenosis

4.1 Definition

  • Mitral stenosis (MS) is a narrowing of the mitral valve orifice that impedes blood flow from the left atrium (LA) to the left ventricle (LV) during diastole.
  • The normal mitral valve area is 4–5 cm²; symptoms typically arise once the area is <2 cm².

4.2 Epidemiology

  • Rheumatic fever is responsible for the vast majority of mitral stenosis cases worldwide, but its prevalence has declined in high-income countries.
  • MS is roughly twice as common in women as in men following rheumatic fever.
  • Although less frequent than in the past, MS remains a classic exam topic.

4.3 Aetiology

  1. Rheumatic Heart Disease (most common cause)
    • Occurs following rheumatic fever; the mitral valve leaflets become thickened, fused, and calcified over years.
    • Often coexists with involvement of other valves (particularly the aortic valve).
  2. Other Causes
    • Congenital anomalies (rare).
    • Mitral annular calcification (age-related, though usually more often causing regurgitation).
    • Previous infective endocarditis, if it has led to scarring or deformity of the mitral apparatus.

4.4 Pathogenesis

  • The narrowed mitral orifice increases resistance to blood flow from LA to LV, leading to elevated left atrial pressure.
  • Chronic elevation of LA pressure → left atrial enlargement, which can precipitate atrial fibrillation (AF).
  • Further back-pressure into the pulmonary circulation leads to pulmonary hypertension, which can eventually cause right-sided heart strain and heart failure if uncorrected.

4.5 Clinical Features

4.5.1 Symptoms

  • Dyspnoea on exertion, orthopnoea, and paroxysmal nocturnal dyspnoea (due to pulmonary congestion).
  • Fatigue (reduced LV filling and cardiac output).
  • Cough from elevated pulmonary venous pressure (possible hemoptysis if small vessel rupture occurs).
  • Palpitations (often due to atrial fibrillation from left atrial enlargement).
  • Chest pain is less common but can occur, often related to pulmonary hypertension or increased LA pressure.

4.5.2 Physical Examination

  1. Malar Flush
    • A rosy appearance on the cheeks, with a greyish/blue facial pallor elsewhere, reflecting chronic hypoperfusion and possible cyanosis in severe MS.
  2. Apex Beat
    • Often described as tapping (palpable first heart sound) but typically not displaced laterally (as LV is not enlarged).
  3. Heart Sounds and Murmur
    • Loud S1 (if the valve remains mobile).
    • An opening snap soon after S2 (the interval between S2 and the snap shortens with increasing severity).
    • A mid-diastolic, low-pitched, rumbling murmur best heard over the apex with the bell of the stethoscope, in the left lateral position, during expiration.
  4. Signs of Pulmonary Hypertension (in advanced disease)
    • Loud P2, right ventricular heave, potential tricuspid regurgitation murmur, elevated jugular venous pressure (JVP), and peripheral oedema.
  5. Atrial Fibrillation
    • Very common; leads to irregularly irregular pulse and can make timing heart sounds/murmurs more challenging.

4.6 Investigations

  1. Electrocardiography (ECG)
    • May show P mitrale (bifid P waves) from LA enlargement.
    • Atrial fibrillation is frequent.
  2. Chest X-Ray
    • Evidence of LA enlargement (straightening of the left heart border, elevated left main bronchus).
    • Pulmonary congestion in more advanced disease.
  3. Echocardiography (Key Investigation)
    • Two-dimensional: Visualizes thickened, fused, or calcified mitral leaflets; reduced valve orifice.
    • Doppler: Measures transvalvular flow, pressure gradients, and can estimate pulmonary artery pressures.
    • Three-dimensional echo: Helps clarify leaflet anatomy and guide intervention.
  4. Cardiac Catheterisation
    • Rarely required solely for diagnosing MS.
    • A Swan–Ganz catheter can measure pulmonary capillary wedge pressure (PCWP) as a surrogate for LA pressure.
    • Left atrial and LV pressure measurements help calculate the mitral valve gradient to confirm severity.

4.7 Management

4.7.1 Medical Therapy

  1. Rate Control in Atrial Fibrillation
    • Beta-blockers or rate-limiting calcium channel blockers (e.g., diltiazem) prolong diastolic filling time.
  2. Diuretics (e.g., loop diuretics)
    • Reduce pulmonary congestion by lowering blood volume and left atrial pressure.
  3. Venodilators (e.g., nitrates)
    • Can help relieve congestion, though used cautiously.
  4. Anticoagulation
    • Indicated in AF to reduce thromboembolic risk (especially stroke).
    • Also in patients with prior embolic events, even if they remain in sinus rhythm.

4.7.2 Percutaneous Balloon Valvuloplasty (Commissurotomy)

  • Preferred for pliable valves with minimal calcification and no significant mitral regurgitation.
  • A balloon is inserted (via femoral vein) across the interatrial septum to split fused commissures.
  • Contraindications: Left atrial thrombus, heavy calcification, significant coexisting MR, or fused subvalvular apparatus.
  • Recurrence of stenosis occurs in ~25% by 5 years.
  • Major complication: Severe mitral regurgitation if the procedure over-splits leaflets.

4.7.3 Surgical Valve Repair or Replacement

  • Reserved for severe, symptomatic MS or when balloon valvuloplasty is unsuitable/contraindicated.
  • Mitral valve repair (open commissurotomy) or replacement with a prosthetic valve may be performed.

4.8 Prognosis

  • Asymptomatic patients often have a long survival: >80% at 10 years.
  • Symptomatic MS has a poorer outlook: only ~10% survive 10 years if untreated, and average survival is <3 years once pulmonary hypertension develops.
  • Timely intervention (medical or percutaneous/surgical) can significantly improve quality of life and outcomes.
Mitral Regurgitation

5. Mitral Regurgitation

5.1 Definition

  • Mitral regurgitation (MR) is the backflow of blood from the left ventricle (LV) into the left atrium (LA)during systole.
  • Can be chronic (slowly progressive) or acute (sudden onset), depending on the underlying cause and time course.

5.2 Epidemiology

  • Trivial MR is common and often clinically insignificant.
  • Significant MR affects ~1–2% of the population, equally in men and women.
  • More frequent in patients with a history of other cardiac diseases (e.g., cardiomyopathy, valve lesions).

5.3 Aetiology

  1. Primary (Organic) Mitral Regurgitation
    • Direct structural lesions of the mitral valve apparatus:
      • Mitral valve prolapse, rheumatic heart disease, infective endocarditis, congenital abnormalities.
      • Leaflet degenerations or tears, chordal rupture, papillary muscle dysfunction.
    • Often slowly progressive but can be acute in chordal rupture or papillary muscle rupture (e.g., post-infarction).
  2. Secondary (Functional) Mitral Regurgitation
    • LV dilatation (e.g., in dilated cardiomyopathy) stretches the mitral annulus.
    • Papillary muscle displacement or ischaemic dysfunction (transient MR during episodes of ischaemia).
  3. Acute Severe Mitral Regurgitation
    • Sudden damage to leaflets, chordae tendineae, or papillary muscle (e.g., myocardial infarction, infective endocarditis, or trauma).
    • Little or no time for compensatory LA and LV dilation → rapid-onset pulmonary oedema and cardiogenic shock.

5.4 Pathophysiology

  • Regurgitant flow into the LA reduces forward stroke volume (cardiac output).
  • Over time:
    • LA dilates to accommodate increased volume.
    • LV experiences volume overload, leading to eccentric hypertrophy and eventual ventricular failure.
    • Pulmonary hypertension may ensue with advanced disease.
  • In acute MR, there is insufficient time for adaptive changes; dramatic falls in cardiac output and acute pulmonary oedema are common.

5.5 Clinical Features

5.5.1 Symptoms

  • Asymptomatic phase is often prolonged in chronic MR; many remain stable for years.
  • When symptomatic, patients may experience:
    • Fatigue, lethargy (reduced forward cardiac output)
    • Dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea (from pulmonary congestion)
    • Cough (in pulmonary congestion)
    • Palpitations, especially if atrial fibrillation develops due to LA enlargement

5.5.2 Signs

  • Laterally displaced apex beat (LV enlargement).
  • Soft S1 and possibly split S2; an S3 can occur with increased LV filling.
  • Pansystolic (holosystolic) murmur:
    • Best heard at the apex and radiating to the left axilla.
    • Often described as a “blowing” murmur.
    • Intensified with maneuvers that increase afterload (e.g., squatting).
  • Signs of pulmonary hypertension (loud P2, right-sided heart failure) in advanced disease.
  • Atrial fibrillation may be present if LA significantly dilated.

5.6 Diagnosis

  1. Clinical Evaluation
    • Characteristic pansystolic murmur at the apex, thorough cardiac history/exam.
  2. Electrocardiogram (ECG)
    • May show left atrial enlargement (P mitrale) or atrial fibrillation.
    • LV hypertrophy in long-standing severe MR.
  3. Chest X-Ray
    • Cardiomegaly (enlarged LA, LV), possible pulmonary venous congestion/oedema if decompensated.
  4. Echocardiography (Key Investigation)
    • Transthoracic Echo (TTE):
      • Evaluates leaflets, chordae, papillary muscles, and annulus for structural lesions.
      • Doppler quantifies regurgitant jet area and direction, LV size/function.
    • Transoesophageal Echo (TOE):
      • Provides superior detail, vital in preoperative assessment.
  5. Left Heart Catheterisation
    • LV end-diastolic pressure measurement helps grade severity.
    • Coronary angiography if concurrent ischaemia suspected (possible CABG along with valve surgery).

5.7 Management

  1. Acute Severe MR
    • Emergency: Usually requires urgent surgical intervention (repair or replacement).
    • Stabilization: IV nitrates, diuretics, continuous positive airway pressure (CPAP), or intra-aortic balloon pump to support cardiac output.
  2. Chronic Primary MR
    • Asymptomatic mild/moderate MR: monitored periodically with echo.
    • Medical therapy has a limited role except to manage:
      • Hypertension (afterload reduction can improve forward output).
      • Atrial fibrillation (anticoagulation, rate/rhythm control).
    • Surgical Repair or Replacement:
      • Mitral valve repair (preferred if feasible): better long-term outcomes than replacement in degenerative disease.
      • Indicated for severe symptomatic MR or asymptomatic patients with LV dysfunction (dilated ventricle or decreased EF) or pulmonary hypertension.
  3. Chronic Secondary (Functional) MR
    • Medical management is key, aiming to optimize LV geometry and function (e.g., ACE inhibitors, beta-blockers, diuretics, aldosterone antagonists).
    • Revascularization if ischaemia contributes to papillary dysfunction.
    • Surgical/Device therapy (valve repair or replacement, or an annuloplasty ring) may be considered if medical therapy fails and LV dysfunction is reversible/stable.
  4. Percutaneous Interventions
    • MitraClip: Leaflet edge-to-edge repair, primarily for functional MR.
    • Annuloplasty devices placed via the coronary sinus are investigational.

5.8 Prognosis

  • In severe MR, especially if the LV dilates and starts to fail, prognosis worsens significantly; 5-year survival can fall to ~33% once LV dysfunction appears.
  • Early surgical intervention (before advanced LV deterioration) improves outcomes.
  • Prognosis also depends heavily on comorbidities, particularly the presence of heart failure in secondary MR.
Mitral Valve Prolapse

6. Mitral Valve Prolapse

6.1 Definition

  • Mitral valve prolapse (MVP) occurs when one or both mitral valve leaflets bulge (prolapse) into the left atrium during systole, beyond the plane of the mitral valve annulus.
  • Sometimes referred to as Barlow’s valve, after the cardiologist who first described it.

6.2 Epidemiology

  • MVP is considered the most prevalent valvular abnormality, affecting up to 5% of the general population (though figures vary by definition).
  • Commonly associated with mitral regurgitation (usually mild but may progress to moderate or severe).
  • Myxomatous degeneration (accumulation of proteoglycan/ground substance) within the leaflets is a frequent underlying pathology.
  • Can be seen in Marfan syndrome, Ehlers–Danlos syndrome or Autosomal Dominant Polycystic Kidney Disease (ADPKD).

6.3 Pathogenesis

  • Excess tissue or lax connective tissue in the leaflets and chordae tendineae → the leaflets billow back toward the LA during systole.
  • If regurgitation is present, it occurs because coaptation is impaired.

6.4 Clinical Features

  1. Symptoms
    • Many patients are asymptomatic, discovered incidentally.
    • Some have atypical chest pain, palpitations, anxiety, or arrhythmias (rare).
  2. Signs
    • Mid-systolic click: Classic finding as the prolapsing leaflets tense during systole (often described analogously to a spinnaker filling with wind).
    • Late systolic murmur: Occurs if mitral regurgitation is present; begins after the click, extending to S2.
    • Maneuvers that increase systemic vascular resistance (e.g., squatting) can delay the click and murmur, making them softer.
  3. Complications
    • Rare but may include infective endocarditis, arrhythmias, and severe mitral regurgitation leading to volume overload of the LV.

6.5 Diagnosis

  1. Clinical Examination
    • Detection of the mid-systolic click ± late systolic murmur.
  2. Echocardiography
    • Primary imaging study, showing billowing leaflets in systole.
    • Can assess any coexisting mitral regurgitation severity.
  3. Additional Tests
    • ECG is often normal unless significant MR or arrhythmias develop.

6.6 Management

  1. Asymptomatic Patients (No MR)
    • Reassure: MVP without regurgitation is typically a benign condition.
    • Periodic monitoring (clinical evaluation and echocardiography every 3–5 years).
  2. Symptomatic Patients
    • Beta-blockers (e.g., propranolol) can relieve palpitations, chest pain, and anxiety.
    • Management of MR (if present) and arrhythmias follows standard guidelines (anticoagulation if AF, etc.).
  3. Surgical Intervention
    • Indications are similar to other forms of mitral regurgitation: severe symptomatic MR, or asymptomatic MR with LV dysfunction or significant LV dilatation.
    • Mitral valve repair is preferred over replacement whenever feasible, offering better long-term outcomes.

6.7 Prognosis

  • Benign in most patients without significant mitral regurgitation.
  • In those with progressive MR, early surgical repair (if indicated) can yield excellent functional outcomes and prevent LV remodeling.
Right-Sided Valve Disease (Tricuspid & Pulmonary Valve Disease)

7. Right-Sided Valve Disease

7.1 Overview

  • Right-sided valve disease primarily involves the tricuspid valve and the pulmonary valve.
  • Significant lesions lead to systemic venous congestion (e.g., elevated jugular venous pressure, peripheral oedema) and can culminate in right ventricular (RV) failure.

7.2 Tricuspid Valve Disease

7.2.1 Tricuspid Stenosis (TS)

  • Rare, most commonly rheumatic or congenital in origin.
  • Often coexists with mitral stenosis if rheumatic.
  • Pathophysiology: Narrowed tricuspid orifice → elevated right atrial pressure → systemic venous congestion.
  • Clinical Features
    • Fatigue, dependent oedema.
    • Elevated JVP with prominent ‘a wave’.
    • Hepatomegaly (congestive).
    • Low-pitched, rumbling diastolic murmur at the lower left sternal edge (best heard on inspiration).
  • Management
    • Rarely requires intervention.
    • If severe, percutaneous valvuloplasty or surgical valve repair/replacement.

7.2.2 Tricuspid Regurgitation (TR)

  • More common than stenosis, often functional (secondary) due to RV dilatation (left-sided heart disease, pulmonary hypertension, left-to-right shunts, etc.).
  • Primary causes include infective endocarditis (particularly IV drug users), rheumatic disease, connective tissue disorders, or congenital anomalies.
  • Pathophysiology: During systole, blood regurgitates from RV to RA → raised RA pressure and venous congestion.
  • Clinical Features
    • Fatigue, dependent oedema, ascites in severe cases.
    • Elevated JVP with prominent ‘v waves’.
    • Pulsatile hepatomegaly.
    • Pansystolic murmur over the lower left sternal edge, louder on inspiration (Carvallo’s sign).
    • Cachexia, jaundice (hepatic congestion) in advanced disease.
    • Possible atrial fibrillation due to RA enlargement.
  • Management
    • Medical: Diuretics (loop, mineralocorticoid antagonists) to reduce volume overload.
    • Surgery:
      • Valve repair or replacement only in severe, isolated TR without major annular dilation.
      • Bioprosthetic valves preferred (lower right-sided pressures elevate thrombosis risk with mechanical valves).
      • Annuloplasty for functional TR is often considered alongside other needed cardiac surgeries.

7.3 Pulmonary Valve Disease

7.3.1 Pulmonary Regurgitation (PR)

  • More common than pulmonary stenosis.
  • Typically acquired, often secondary to pulmonary arterial hypertension (PAH), but can also result from infective endocarditis or connective tissue disease.
  • Pathophysiology: Backflow from pulmonary artery to RV during diastole → RV volume overload → eventual RV failure.
  • Clinical Features
    • Symptoms/signs of RV failure: fatigue, elevated JVP, peripheral oedema.
    • Early diastolic decrescendo murmur, analogous to aortic regurgitation, best heard in the 3rd–4th left intercostal space, louder on inspiration.
  • Management
    • Address the underlying cause, e.g., treat pulmonary hypertension.
    • Diuretics if RV failure is present.
    • Valve replacement in select severe cases (e.g., significant RV dysfunction or enlargement).

7.3.2 Pulmonary Stenosis (PS)

  • Often congenital, may be supravalvular, valvular, or subvalvular.
  • Commonly diagnosed in childhood; can be asymptomatic initially.
  • Pathophysiology: Obstruction to RV outflow → RV pressure overload → potential RV hypertrophy/failure.
  • Clinical Features
    • May remain asymptomatic if mild.
    • Ejection systolic murmur at the pulmonary area (left upper sternal border).
    • Right-sided heart failure symptoms if severe or longstanding.
  • Management
    • Balloon valvuloplasty or surgical valvotomy in severe symptomatic cases.
    • Valve replacement in cases with significant valve deformities or if repair is not feasible.
Rheumatic Heart Disease

8. Rheumatic Heart Disease

8.1 Definition

  • Rheumatic heart disease is a chronic inflammatory condition affecting the cardiac valves, especially the mitraland aortic valves.
  • It represents the most serious long-term complication of rheumatic fever, an autoimmune sequela of group A β-hemolytic streptococcal infection.

8.2 Epidemiology

  • An estimated 15 million individuals worldwide have rheumatic heart disease.
  • Prevalence in high-income countries has declined significantly, mirroring the drop in rheumatic fever incidence.
  • Low- and middle-income countries bear the greatest burden, where it remains a leading cause of valvular heart disease and is the primary cause of mitral stenosis globally.

8.3 Rheumatic Fever

8.3.1 Pathophysiology (Acute Phase)

  • Rheumatic fever typically arises 2–5 weeks after streptococcal pharyngitis (Streptococcus pyogenes).
  • Molecular mimicry: Antibodies against the bacterial M protein cross-react with human tissues (e.g., myocardium, joints).
  • Affects multiple organ systems; the heart involvement can include endocarditis, myocarditis, and pericarditis (pancarditis).

8.3.2 Clinical Diagnosis

  • Modified Jones Criteria:
    1. Evidence of recent group A strep infection (throat culture, elevated ASO, anti-DNase B titers).
    2. Major Criteria (any two or one plus two minor criteria):
      • Migratory polyarthritis (large joints, resolves and migrates)
      • Carditis (pancarditis: endo-, myo-, peri-carditis)
      • Subcutaneous nodules
      • Erythema marginatum (annular rash, trunk/limbs)
      • Sydenham chorea (rapid, involuntary movements)
    3. Minor Criteria:
      • Fever, arthralgia, elevated acute-phase reactants (ESR, CRP), ECG changes (prolonged PR interval), previous rheumatic fever episodes.

8.3.3 Cardiac Manifestations

  1. Endocarditis
    • Mitral valve more frequently affected than aortic; small vegetations along closure lines → regurgitation.
  2. Myocarditis
    • Characterized by Aschoff bodies (foci of chronic inflammation, reactive histiocytes ‘Anitschkow cells’, giant cells, fibrinoid material).
    • Most common cause of death during the acute phase.
  3. Pericarditis
    • Causes chest pain, friction rub, possible pericardial effusion.

8.3.4 Management of Rheumatic Fever

  • Eradicate streptococcal infection:
    • Antibiotics (e.g., penicillin or macrolides) for acute infection.
    • Long-term prophylaxis (monthly penicillin injections) for ≥5 years after the episode or until age 18.
  • Control inflammation:
    • NSAIDs for arthritis and mild carditis.
    • Corticosteroids for severe carditis.
  • Close cardiac monitoring in hospital if carditis is present.

8.4 Chronic Rheumatic Heart Disease

8.4.1 Pathophysiology (Chronic Phase)

  • Repeated or severe acute episodes → progressive fibrosis, scarring, and deformity of valve leaflets and chordae tendineae (especially the mitral valve).
  • “Fish-mouth” stenosis can develop, particularly in the mitral valve.
  • Aortic valve involvement also possible, typically alongside mitral pathology.

8.4.2 Clinical Consequences

  1. Mitral Stenosis:
    • Most common valvular outcome of chronic rheumatic disease; often presents decades after the initial rheumatic fever.
  2. Aortic Stenosis:
    • Fusion of aortic commissures, typically coexisting with mitral stenosis.
  3. Tricuspid Stenosis:
    • Less common, but can occur in severe or advanced rheumatic involvement (again, usually with coexisting mitral disease).
  4. Heart Failure:
    • Permanent myocardial damage can cause chronic left ventricular dysfunction.
  5. Infective Endocarditis:
    • Scarred valves are more susceptible to secondary infection.

8.4.3 Prognosis

  • ~50% of rheumatic fever cases progress to rheumatic heart disease; risk is higher (~90%) if carditis occurs in the initial attack.
  • Early antibiotic therapy and prophylaxis reduce the likelihood of progression.
  • Chronic valve lesions (especially mitral stenosis) can be debilitating if untreated.
Infective Endocarditis

9. Infective Endocarditis

9.1 Definition and Basic Principles

  • Infective endocarditis (IE) is an inflammation of the endocardium, most often affecting heart valves (native or prosthetic).
  • It is usually bacterial in origin and leads to vegetation formation (microbes, inflammatory cells, fibrin, and platelets), potentially causing valvular incompetence, heart failure, emboli, and death if not recognised and treated promptly.

9.2 Epidemiology

  • Estimated incidence in the general population: ~6 cases per 100,000 patient-years.
  • Higher incidence in at-risk groups:
    • Intravenous drug users (often right-sided IE)
    • Pre-existing valve disease (e.g., rheumatic, degenerative)
    • Prosthetic valve recipients
    • Previous endocarditis
    • Poor dental health and/or men (male:female ratio ~2:1)

9.3 Aetiology and Causative Organisms

  1. Streptococcus viridans (“Oral Streptococci”)
    • Most common overall cause of IE.
    • Low virulence organism that typically infects damaged valves (e.g., chronic rheumatic heart disease, mitral valve prolapse).
    • Produces small vegetations that do not destroy the valve → subacute presentation.
  2. Staphylococcus aureus
    • Most common cause in IV drug users.
    • High virulence organism that often infects normal valves (especially the tricuspid).
    • Leads to large vegetations that can destroy the valve → acute endocarditis.
  3. Staphylococcus epidermidis
    • Frequently associated with prosthetic valves (coagulase-negative staphylococci).
  4. Streptococcus bovis
    • Linked to underlying colorectal carcinoma; finding S. bovis IE warrants GI evaluation.
  5. HACEK Organisms
    • Haemophilus, Aggregatibacter (Actinobacillus), Cardiobacterium, Eikenella, Kingella
    • Slow-growing Gram-negative bacteria causing culture-negative endocarditis.
  6. Enterococci, Fungi, or Culture-Negative States
    • Enterococci: about 10% of cases.
    • Fungal endocarditis is rare, often in immunocompromised patients.
    • Culture-negative may reflect prior antibiotic use, difficult organisms, or non-infective etiologies.
  7. Non-infective (Marantic) Endocarditis
    • Sterile vegetations associated with hypercoagulable states or adenocarcinoma.
    • Vegetations commonly along lines of valve closure, can lead to regurgitation.
    • Libman-Sacks Endocarditis: Sterile vegetations in SLE, on both surfaces of the mitral valve → mitral regurgitation.

9.4 Pathogenesis and Risk Factors

  • Damaged Endocardium: Congenital or acquired valve lesions predispose to platelet-fibrin deposition.
  • Transient Bacteremia: From dental procedures, poor dental hygiene, IV injections, or instrumentation seeds vegetations on valves.
  • IV Drug Use: Typically affects right-sided valves (tricuspid).
  • Prosthetic Materials: Prosthetic valves or pacemaker leads serve as a focus for infection.
  • Hypercoagulable States / Malignancy / Autoimmune: May lead to sterile (non-infective) vegetations.

9.5 Clinical Features

9.5.1 Presentation

  • Subacute (Streptococcus viridans):
    • Insidious onset, low-grade fever, malaise, weight loss.
    • Vegetations do not severely damage valves.
  • Acute (Staphylococcus aureus):
    • Rapid onset, high fevers, rigors.
    • Large vegetations, valve destruction, heart failure risk.

9.5.2 Symptoms

  • Fever (most common), night sweats, lethargy, anorexia, weight loss.
  • Heart failure symptoms (if severe valvular incompetence develops).

9.5.3 Signs

  • New or changing murmur (regurgitant lesion)
  • Immune complex / Embolic phenomena:
    • Janeway lesions (painless, erythematous on palms/soles)
    • Osler nodes (tender lesions on fingers/toes)
    • Splinter hemorrhages (nail beds)
    • Roth spots (retinal hemorrhages with pale centers)
  • Tachycardia, pyrexia
  • Anaemia of chronic disease (↓Hb, normal-low MCV, ↑ferritin, ↓TIBC, ↓serum iron)
  • Clubbing, splenomegaly in more chronic cases

9.5.4 Embolic Complications

  • Left-sided IE: Systemic emboli → stroke, renal or splenic infarctions.
  • Right-sided IE: Pulmonary emboli → septic infarcts in lungs.

9.6 Diagnosis

  1. High Index of Suspicion
    • Non-specific clinical features require vigilance in at-risk individuals.
  2. Blood Cultures
    • ≥3 sets (10 mL each) from different sites, ideally before antibiotics.
    • Helps identify organism, guide antibiotic selection.
  3. Laboratory Tests
    • Inflammatory markers: CRP, ESR often elevated.
    • FBC: Normocytic anaemia of chronic disease.
    • Serology for difficult organisms (e.g., HACEK).
  4. Echocardiography
    • Transthoracic (TTE): First-line to look for vegetations, valve abnormalities.
    • Transoesophageal (TOE): Higher sensitivity, especially in prosthetic valves, posterior structures, or aortic root abscess suspicion.
  5. Additional
    • ECG: Monitor conduction (especially in aortic root involvement).
    • Other imaging (CT/MRI) if septic emboli or organ complications suspected.

9.7 Management

  1. Multidisciplinary Care
    • Involving cardiologists, cardiac surgeons, infectious disease specialists, microbiologists.
    • Dental evaluation: Identify/eliminate oral infection sources.
  2. Antibiotic Therapy
    • Prompt IV antibiotics for at least 4–6 weeks.
    • Empiric coverage while awaiting cultures, then tailored to organism sensitivities.
    • Monitor blood cultures and inflammatory markers for response.
  3. Surgical Intervention
    • Indications for urgent surgery:
      • Severe valvular dysfunction → heart failure.
      • Prosthetic valve endocarditis with uncontrolled sepsis.
      • Persistent infection despite antibiotics.
      • Large vegetations (risk of embolism) or recurrent emboli.
      • Aggressive organisms (e.g., S. aureus, fungal).
    • Valve repair or replacement performed if destruction is extensive.
  4. Monitoring
    • Repeat echocardiograms, ECGs, blood cultures, CRP levels.
    • Watch for complications: conduction blocks, embolic events, heart failure.

9.8 Prognosis

  • Untreated IE is universally fatal.
  • Even with appropriate therapy, mortality ~20%, higher with:
    • Aggressive organisms (S. aureus)
    • Large vegetations or advanced left-sided disease
    • Heart failure or multi-organ involvement
  • Right-sided endocarditis often has a better prognosis due to fewer systemic emboli and more tolerance for tricuspid dysfunction.

9.9 Prevention and Prophylaxis

  1. At-Risk Patients
    • Prosthetic valves or valve repairs with prosthetic material (high risk).
    • History of infective endocarditis (high risk).
    • Certain congenital heart lesions, acquired valvular disease, HOCM.
  2. Procedures with Bacteraemia Risk
    • Dental procedures, especially in presence of infection or gingival manipulation.
    • GI/GU instrumentation, infected tissue surgery, or ENT manipulations.
  3. Guidelines
    • Good oral hygiene and regular dental review essential.
    • Prophylactic antibiotics use is controversial; current practice limits prophylaxis to high-risk patients undergoing high-risk procedures, based on local and international guidelines.
  4. Education
    • Patients should know the signs/symptoms of IE (fever, malaise, etc.) and seek early care if suspected.
    • Aseptic technique during venous catheterisation or invasive procedures is critical.
Written by Dr Ahmed Kazie MD, MSc
  • References
    1. Morris P, Warriner D, Morton A. Eureka: Cardiovascular Medicine. Scion Publishing Ltd; 2015.
    2. Sattar HA. Fundamentals of pathology : medical course and step 1 review. Chicago, Illinois: Pathoma.com; 2024

Last Updated: January 2025