Mixed Mitral Valve Disease

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Rheumatic mitral valve disease with moderate mitral regurgitation and a mean mitral diastolic gradient > 10 mm Hg and valve area of 1.1–1.5 cm² (moderate mitral stenosis)

GENERAL CONSIDERATIONS

• Mixed mitral valvular disease is frequently rheumatic in origin

• The clinical course is similar to that of mitral regurgitation alone

• The difference is that left atrial pressure rises proportionately more than left ventricular diastolic pressure, resulting in:

  • – Earlier appearance of pulmonary congestion

  • – More severe pulmonary hypertension

  • – A higher incidence of atrial fibrillation

• Forward cardiac output is reduced more compared with pure mitral regurgitation owing to reduced left ventricular filling, resulting in earlier symptoms of fatigue and reduced exercise performance

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Dyspnea on exertion, fatigue

• Edema, abdominal distention

PHYSICAL EXAM FINDINGS

• Jugular venous pressure may be elevated with a prominent a wave in sinus rhythm when pulmonary hypertension is present

• Evidence of edema, ascites, and pleural effusions

• Right ventricular lift

• Loud pulmonic component of S₂

• Opening snap followed by a low-pitched diastolic rumble at the apex

• Blowing holosystolic murmur at the apex

DIFFERENTIAL DIAGNOSIS

• Mild mitral regurgitation or mild mitral stenosis

• Severe mitral regurgitation or mitral stenosis; the severe lesion dominates management

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC: rarely, hemolytic anemia may be present from red cell trauma

ELECTROCARDIOGRAPHY

• ECG findings:

  • – Right ventricular hypertrophy

  • – Left ventricular voltage increased

  • – Left atrial enlargement in sinus rhythm

  • – Atrial fibrillation in some

IMAGING STUDIES

• Chest x-ray:

  • – Enlargement of all 4 cardiac chambers

  • – Dilated main pulmonary arteries

  • – Pulmonary congestion

  • – Pleural effusion

  • – Relatively small aorta

• Echocardiography:

  • – Enlargement of all 4 cardiac chambers

  • – Thickened mitral valve with diastolic doming

  • – Usually, normal left ventricular function

  • – Doppler evidence of pulmonary hypertension

  • – Doppler echocardiography of mitral stenosis

  • – Color Doppler visualization of the mitral regurgitation

DIAGNOSTIC PROCEDURES

• Cardiac catheterization may be useful to quantify the degree of mitral stenosis and pulmonary hypertension

TREATMENT

CARDIOLOGY REFERRAL

• Symptoms

• Heart failure or other complications

HOSPITALIZATION CRITERIA

• Heart failure

• Rapid atrial fibrillation

MEDICATIONS

• Drugs to control heart rate in atrial fibrillation, such as beta blockers, selected calcium blockers, and anticoagulation agents

• Diuretics for congestion and edema

• Angiotensin-converting enzyme inhibitors or receptor blockers for left ventricular dysfunction

THERAPEUTIC PROCEDURES