Signs and Symptoms of Mitral Stenosis
Mitral stenosis presents with exertional dyspnea as the most common symptom, accompanied by characteristic auscultatory findings of a diastolic rumbling murmur at the apex with an opening snap, though the diagnosis may be missed in elderly patients with comorbidities. 1
Clinical Symptoms
Primary Symptoms
- Exertional dyspnea develops gradually as the most common presenting symptom, often with patients unconsciously reducing activity levels to avoid symptoms 1
- Fatigue is frequently reported and may be more prominent than dyspnea in some patients 1
- Palpitations occur commonly, especially with development of atrial fibrillation 1
- Hemoptysis may occur due to pulmonary hypertension and rupture of bronchial veins 1
Symptom Assessment Pitfalls
- Symptoms may be absent or subtle even in severe mitral stenosis due to enhanced left atrial compliance accommodating large volumes without pressure elevation 1
- Patients often subconsciously reduce activity levels, making symptom assessment challenging 1
- Family members frequently report diminished activity levels that patients themselves are unaware of 1
- Ask specifically what the most vigorous activity the patient currently undertakes is and compare with previous capabilities 2
Advanced Disease Manifestations
- Heart failure symptoms are the predominant presentation in 94% of symptomatic patients, with 64% in NYHA class III or IV 2
- Right heart failure signs develop in advanced disease with pulmonary hypertension 1
- In children, symptoms may be limited to tachypnea, dyspnea, and failure to thrive 2
Physical Examination Findings
Cardiac Auscultation
- Diastolic rumbling murmur best heard at the apex with the patient in left lateral position 1
- Opening snap followed by a low-pitched diastolic murmur 1
- Loud S1 in early disease, which becomes softer as the valve calcifies 1
- The presence of a diastolic filling sound is characteristic in primary mitral stenosis 2
Associated Findings
- Atrial fibrillation is common, especially as disease progresses 1
- Signs of pulmonary hypertension in advanced disease 1
- Right heart failure signs including elevated jugular venous pressure, hepatomegaly, and peripheral edema 1
Hemodynamic Severity Classification
Mild Mitral Stenosis
- Mitral valve area >1.5 cm² 2, 1
- Mean gradient <5 mmHg 2, 1
- Pulmonary artery systolic pressure <30 mmHg 2, 1
Moderate Mitral Stenosis
- Mitral valve area 1.0-1.5 cm² 2, 1
- Mean gradient 5-10 mmHg 2, 1
- Pulmonary artery systolic pressure 30-50 mmHg 2, 1
Severe Mitral Stenosis
- Mitral valve area <1.0 cm² 2, 1
- Mean gradient >10 mmHg 2, 1
- Pulmonary artery systolic pressure >50 mmHg 2, 1
Diagnostic Challenges
Unsuspected Mitral Stenosis
- The diagnosis may be missed in elderly patients (median age 72 years) with comorbidities 3
- Eight common scenarios where diagnosis is missed:
- Evaluation for congestive heart failure 3
- Evaluation for aortic valve disease 3
- Cerebrovascular accidents with atrial fibrillation 3
- Advanced age obscuring physical findings 3
- Other serious cardiac conditions distracting from mitral pathology 3
- Mechanical factors complicating physical examination 3
- Presence of lung disease 4
- Concomitant arterial hypertension 4
Exercise Testing for Symptom Elicitation
- Exercise testing may safely elicit symptoms or demonstrate reduced exercise capacity in apparently asymptomatic patients 2, 1
- Echocardiographic imaging during exercise may reveal elevated pulmonary artery systolic pressures, worsening mitral stenosis, or failure of ventricular function to augment normally 2
- Exercise testing can reclassify patients from asymptomatic (Stage C) to symptomatic (Stage D) 2
- The 6-minute walk test is simple, inexpensive, and reproducible for assessing functional capacity, particularly in frail or elderly patients 2