# Clinical Cases: Valvular Heart Disease

## Case 1: Severe Aortic Stenosis - Classic Presentation

### Patient Presentation
**Demographics:** 78-year-old male

**Chief Complaint:** Exertional chest pain and dyspnea for 3 months

**History of Present Illness:**
A 78-year-old male with history of hypertension and hyperlipidemia presents with progressive exertional symptoms over the past 3 months. He reports substernal chest pressure when walking up hills or climbing stairs, relieved by rest within 5 minutes. He also experiences dyspnea with exertion and has had two episodes of lightheadedness (near-syncope) after climbing a flight of stairs. He denies symptoms at rest. His primary care physician heard a heart murmur and referred him for evaluation.

**Physical Examination:**
- Vital Signs: BP 124/82 mmHg, HR 72 bpm, RR 16/min, SpO2 97% on room air
- General: Elderly male, no acute distress at rest
- Cardiovascular:
  - **Murmur:** 4/6 harsh, crescendo-decrescendo systolic ejection murmur at right upper sternal border
  - **Radiation:** Murmur radiates to carotid arteries bilaterally
  - **Carotid pulse:** Parvus et tardus (weak and delayed upstroke)
  - **S2:** Soft (diminished A2 component)
  - **S4:** Present (atrial gallop)
  - PMI sustained, not displaced
- Lungs: Clear
- Extremities: No edema

### Workup
- **ECG:** Sinus rhythm, LVH by voltage criteria, secondary repolarization abnormalities
- **Chest X-ray:** Normal heart size, calcified aortic valve visible on lateral view
- **Echocardiogram:**
  - **Aortic valve:** Heavily calcified, restricted leaflet motion
  - **Aortic valve area:** 0.7 cm2 (severe <1.0 cm2)
  - **Mean gradient:** 52 mmHg (severe >40 mmHg)
  - **Peak velocity:** 4.8 m/s (severe >4.0 m/s)
  - **LV ejection fraction:** 55%
  - **Concentric LVH:** Wall thickness 1.5 cm
- **Coronary Angiography:** Moderate non-obstructive CAD

### Diagnosis
**Severe symptomatic degenerative aortic stenosis with classic symptom triad**

*Valvular Heart Disease Correlation:*

**Pathophysiology of Aortic Stenosis:**

1. **Etiology - Degenerative Calcification:**
   - Most common cause in elderly patients (>65 years)
   - Calcification of tricuspid aortic valve
   - Similar risk factors to atherosclerosis
   - Progressive narrowing over decades

2. **Pressure Overload on Left Ventricle:**
   - LV must generate higher pressure to eject through narrowed orifice
   - Response: Concentric hypertrophy (sarcomeres in parallel)
   - Wall thickness increases to normalize wall stress
   - LaPlace: Wall stress = (Pressure x radius) / (2 x wall thickness)

3. **Consequences of Concentric LVH:**
   - Increased myocardial oxygen demand
   - Decreased compliance (diastolic dysfunction)
   - Subendocardial ischemia (compression of intramyocardial vessels)
   - S4 gallop from forceful atrial contraction

**Classic Symptom Triad and Mechanisms:**

| Symptom | Mechanism | Prognosis Without Treatment |
|---------|-----------|----------------------------|
| **Angina** | Supply-demand mismatch, subendocardial ischemia | 50% 5-year survival |
| **Syncope** | Fixed cardiac output cannot increase with exertion; vasodilation without CO increase | 50% 3-year survival |
| **Heart Failure** | Decompensated LV dysfunction | 50% 2-year survival |

**Physical Examination Findings Explained:**

- **Crescendo-decrescendo murmur:** Turbulent flow through stenotic valve
- **Late-peaking murmur:** In severe AS, peak is delayed as ejection time prolongs
- **Radiation to carotids:** High-velocity jet directed toward ascending aorta
- **Parvus et tardus:** Slow rise and low amplitude of arterial pulse reflects fixed obstruction
- **Soft S2:** Calcified valve closes poorly, diminished A2
- **S4 gallop:** Stiff LV requires forceful atrial contraction

**Severity Assessment:**

| Parameter | Mild | Moderate | Severe |
|-----------|------|----------|--------|
| Valve area (cm2) | >1.5 | 1.0-1.5 | <1.0 |
| Mean gradient (mmHg) | <25 | 25-40 | >40 |
| Peak velocity (m/s) | <3.0 | 3.0-4.0 | >4.0 |

### Treatment
**Indication for Intervention:**
- Severe AS + Symptoms = Class I indication for valve replacement
- Asymptomatic severe AS with EF <50% = Also Class I indication

**Options:**
1. **Surgical Aortic Valve Replacement (SAVR):**
   - Traditional approach
   - Excellent durability
   - Requires sternotomy and cardiopulmonary bypass

2. **Transcatheter Aortic Valve Replacement (TAVR):**
   - Catheter-based approach (femoral or alternative access)
   - Now approved for all surgical risk categories
   - Preferred for high/prohibitive surgical risk
   - Comparable outcomes to SAVR in intermediate risk

**Choice for This Patient:**
- Age 78, moderate non-obstructive CAD, good LV function
- Heart team discussion
- TAVR likely appropriate given age and comorbidities
- SAVR remains option if complex anatomy

**Medical Management (Supportive only):**
- No medical therapy alters AS progression
- Maintain euvolemia
- Avoid hypotension (fixed obstruction)
- Treat atrial fibrillation aggressively if develops

### Clinical Image
![Aortic Stenosis](case_01_image.jpg)

**Image Description:** Gross pathological specimen of a severely stenotic aortic valve with rheumatic changes. The valve leaflets show marked thickening, calcification, and commissural fusion resulting in a significantly narrowed orifice. This illustrates the structural abnormality that creates obstruction to left ventricular outflow.

**Source:** Wikimedia Commons - Aortic stenosis, rheumatic
**License:** Public Domain (CDC/Dr. Edwin P. Ewing, Jr.)
**URL:** https://commons.wikimedia.org/wiki/File:Aortic_stenosis_rheumatic,_gross_pathology_20G0014_lores.jpg

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## Case 2: Acute Severe Mitral Regurgitation - Papillary Muscle Rupture

### Patient Presentation
**Demographics:** 62-year-old male

**Chief Complaint:** Sudden severe shortness of breath

**History of Present Illness:**
A 62-year-old male with no significant medical history presents with sudden onset of severe dyspnea that began 1 hour ago. He was in his usual state of health until yesterday when he experienced substernal chest pressure for approximately 30 minutes that resolved spontaneously (he did not seek medical attention). Today, he suddenly became severely short of breath at rest with orthopnea. He denies fever, cough, or leg swelling.

**Physical Examination:**
- Vital Signs: BP 88/62 mmHg, HR 115 bpm, RR 32/min, SpO2 82% on room air
- General: Severe respiratory distress, diaphoretic, using accessory muscles
- Cardiovascular:
  - Tachycardic, regular rhythm
  - **Murmur:** 3/6 holosystolic murmur at apex, radiating to axilla
  - **Murmur quality:** Harsh, may have decrescendo component
  - S3 gallop present
  - JVP markedly elevated
- Lungs: Diffuse bilateral crackles to apices (pulmonary edema)
- Extremities: Cool, mottled

### Workup
- **ECG:** Sinus tachycardia, ST elevation in inferior leads (II, III, aVF) - acute inferior STEMI
- **Troponin I:** 18.2 ng/mL (markedly elevated)
- **BNP:** 2,400 pg/mL
- **Chest X-ray:** Diffuse bilateral pulmonary edema, normal heart size
- **Echocardiogram (emergent):**
  - Severe mitral regurgitation with eccentric jet
  - Flail posterior mitral leaflet
  - Ruptured posteromedial papillary muscle
  - Inferior wall akinesis
  - Hyperdynamic LV (EF 60%)
  - LA not dilated (acute process)

### Diagnosis
**Acute severe mitral regurgitation due to papillary muscle rupture complicating inferior STEMI**
**Cardiogenic shock**

*Valvular Heart Disease Correlation:*

**Pathophysiology of Acute MR:**

1. **Mechanism - Papillary Muscle Rupture:**
   - Inferior STEMI from RCA occlusion
   - Posteromedial papillary muscle has single blood supply (RCA or LCx)
   - Ischemia/infarction weakens papillary muscle
   - Rupture typically 2-7 days post-MI
   - Results in flail mitral leaflet and severe MR

2. **Why Acute MR is Catastrophic:**
   - Normal LA compliance: small, stiff
   - Cannot accommodate sudden regurgitant volume
   - LA pressure rises dramatically
   - Transmitted immediately to pulmonary veins
   - Flash pulmonary edema

3. **Hemodynamic Consequences:**
   - **Forward failure:** Reduced effective cardiac output
   - **Backward failure:** Pulmonary edema
   - **Low systemic BP + High pulmonary pressure = Cardiogenic shock**

**Acute vs. Chronic MR:**

| Feature | Acute MR | Chronic MR |
|---------|----------|------------|
| LA size | Normal | Enlarged |
| LA compliance | Low | High (adapted) |
| Pulmonary edema | Severe | May be minimal |
| Murmur intensity | May be soft (early decrescendo) | Holosystolic |
| LV size | Normal | Dilated |
| LV EF | Often hyperdynamic | May be normal or reduced |

**Why Murmur May Be Soft:**
- Very severe MR can produce softer murmur
- Pressure equalization between LV and LA reduces gradient
- Decrescendo pattern as LA pressure rises in systole

**Why Heart Size is Normal on CXR:**
- Acute process - no time for chamber remodeling
- LV and LA have not had time to dilate
- Contrast with chronic MR where cardiomegaly is typical

### Treatment
**This is a Surgical Emergency**

**Immediate Stabilization:**
1. **Intubation and mechanical ventilation** for respiratory failure
2. **Vasopressors** for BP support (norepinephrine)
3. **Afterload reduction (if BP permits):**
   - Nitroprusside reduces regurgitant fraction
   - Increases forward flow
   - Caution: may worsen hypotension
4. **Intra-aortic balloon pump (IABP):**
   - Diastolic augmentation increases coronary perfusion
   - Systolic deflation reduces afterload
   - Reduces regurgitant volume

**Definitive Treatment:**
1. **Emergent cardiac surgery:**
   - Mitral valve repair or replacement
   - Concomitant coronary bypass if indicated
   - Cannot delay for medical stabilization
2. **Coronary angiography** en route to OR or intraoperatively
   - Identify culprit lesion
   - Plan revascularization

**Prognosis:**
- Without surgery: >90% mortality
- With prompt surgery: 40-50% operative mortality (still high)
- Survival depends on rapid recognition and intervention

### Clinical Pearl
**Mechanical Complications of MI:**

| Complication | Timing | Presentation | Treatment |
|--------------|--------|--------------|-----------|
| Papillary muscle rupture | 2-7 days | Acute MR, pulmonary edema | Emergent surgery |
| Ventricular septal rupture | 3-5 days | New murmur, biventricular failure | Emergent surgery |
| Free wall rupture | 3-5 days | Tamponade, PEA | Emergent surgery |

**Key Teaching Points:**
- Any new murmur post-MI requires urgent echocardiography
- Acute severe MR presents differently than chronic MR
- Normal heart size + pulmonary edema = think acute process
- Papillary muscle rupture is a surgical emergency - medical therapy is bridge only