What are the primary symptoms and management strategies for a patient with mitral valve stenosis?

Mitral Stenosis: Primary Symptoms and Management

Patients with mitral stenosis often remain asymptomatic until the disease is advanced, but when symptoms develop, they primarily include dyspnea on exertion, fatigue, palpitations, and signs of pulmonary congestion—with intervention indicated when symptoms occur alongside severe stenosis (valve area ≤1.5 cm²). 1, 2

Primary Symptoms

Cardinal Presenting Symptoms

• Dyspnea on exertion is the most common symptom, occurring when elevated left atrial pressure transmits upstream to the pulmonary vasculature 1, 2
• Fatigue develops as cardiac output fails to augment appropriately with activity 1
• Palpitations frequently occur, particularly with the onset of atrial fibrillation, which is common in mitral stenosis 1
• Hemoptysis may occur in patients with severe disease and pulmonary hypertension 3
• Orthopnea and paroxysmal nocturnal dyspnea indicate advanced disease with pulmonary congestion 2

Physical Examination Findings

• A shortened A2-opening snap (OS) interval correlates with higher left atrial pressure and more severe stenosis—this is a critical bedside indicator for disease severity 1
• Longer duration of the middiastolic murmur indicates more severe stenosis requiring closer monitoring 1
• Signs of pulmonary hypertension (right ventricular heave, loud P2, tricuspid regurgitation murmur) suggest advanced disease 1

Critical Pitfall: Asymptomatic Presentation

Many patients remain asymptomatic despite severe stenosis due to enhanced left atrial compliance and subconscious activity reduction 1, 2. Always ask patients to compare their current maximum activity level with what they could do previously, and involve family members who may report limitations the patient doesn't recognize. 1

Diagnostic Assessment

Initial Evaluation

• Obtain echocardiography immediately to assess mitral valve area, mean gradient, valve morphology, and pulmonary artery pressure in all patients with suspected significant mitral stenosis 1
• Planimetry of the valve area is the reference standard measurement 2
• Assess NYHA functional class as this directly drives intervention timing 1

Severity Classification

• Severe mitral stenosis is defined as valve area ≤1.0 cm² with mean transmitral gradient ≥10 mmHg 2
• Clinically significant stenosis requiring consideration for intervention is valve area <1.5 cm² 2

Exercise Testing for Discordant Cases

When symptoms and resting echocardiography don't align, exercise testing with Doppler echocardiography can reveal elevated pulmonary artery pressure (>60 mmHg), mean transmitral gradient (>15 mmHg), or pulmonary artery wedge pressure (>25 mmHg) that confirms hemodynamically significant stenosis. 4, 5

Management Strategy

Medical Management (All Patients)

Strict heart rate control is the cornerstone of medical therapy—use beta-blockers, digoxin, or rate-limiting calcium channel blockers to prolong diastolic filling time and prevent pulmonary congestion 1, 2. Tachycardia is the primary trigger for acute decompensation because it shortens diastolic filling time across the stenotic valve, rapidly increasing left atrial pressure 4, 1.

• Diuretics for volume management to reduce pulmonary congestion 1, 2
• Immediate anticoagulation if new-onset atrial fibrillation develops due to high thromboembolic risk 1

Intervention Indications

Percutaneous mitral balloon commissurotomy (PMC) is first-line treatment for symptomatic severe rheumatic mitral stenosis with favorable valve morphology (no significant calcification, no major mitral regurgitation, preserved subvalvular apparatus). 1, 2, 6

Specific indications for intervention:

• NYHA class II-IV symptoms with severe stenosis (valve area ≤1.5 cm²) 2
• Development of pulmonary hypertension >50 mmHg in previously asymptomatic patients warrants consideration for PMC 1
• Symptoms at low exercise levels despite optimal medical management 1

For patients with unfavorable valve morphology (heavy calcification, significant mitral regurgitation, subvalvular fusion), proceed directly to open surgical repair or mitral valve replacement 1, 3. For degenerative mitral stenosis from mitral annular calcification, mitral valve replacement is the primary surgical option as there is no commissural fusion to address 2.

Surveillance for Asymptomatic Patients

• Yearly clinical and echocardiographic follow-up for severe asymptomatic mitral stenosis 1
• Every 2-3 years for less severe disease 2

Critical Perioperative Considerations

For patients undergoing noncardiac surgery:

• Avoid vasopressors like midodrine—increased afterload reduces cardiac output and exacerbates pulmonary congestion 1
• Maintain strict heart rate control perioperatively as tachycardia precipitates acute decompensation 1
• Invasive hemodynamic monitoring during high-risk procedures to optimize preload (high enough for adequate forward flow but low enough to avoid pulmonary edema) while avoiding rapid volume shifts and arrhythmias 4, 1
• In patients with pulmonary artery systolic pressure >50 mmHg, the risk of elective intermediate- to high-risk noncardiac surgery is considerably higher—these patients should be evaluated for mitral stenosis intervention before elective surgery 4

Special Populations

Pregnancy planning in severe mitral stenosis requires pre-conception intervention because pregnancy increases cardiac output and can precipitate heart failure 1. The hemodynamic demands of pregnancy are poorly tolerated with significant mitral stenosis.