Regurgitation, mitral (MR)

• Mitral valve regurgitation
• Mitral valve insufficiency
• Left atrial overload

• 394.1 Rheumatic mitral insufficiency
• 424.0 Mitral valve disorders
• 746.6 Congenital mitral insufficiency

• I05.1 Rheumatic mitral insufficiency
• I34.0 Nonrheumatic mitral (valve) insufficiency
• Q23.3 Congenital mitral insufficiency

• 6D: Impaired aerobic capacity/endurance associated with cardiovascular pump dysfunction or failure1

Description

• Mitral valve does not close properly during systolic contraction of left ventricle
• Causes backflow and fluid overload in left atrium
• Fluid overload in left atrium can lead to weakening of left atrial wall
• Fluid overload in left atrium can also cause pooling and clotting in left atrium
• MR is most common type of valvular heart disease

Essentials of Diagnosis

• Stethoscope for auscultation systolic murmur in mitral position
• EKG/ECG2
• Echocardiogram

General Considerations

• Patients with significant MR can show signs and symptoms of congestive heart failure
• Strenuous activity should be limited for symptomatic MR
• Signs and symptoms should be monitored
• Can lead to sudden cardiac death, arrhythmias, embolic events, and coronary disease
• Patients can develop bacterial endocarditis
• Valve problems can develop 5 to 10 years after rheumatic fever
• Ischemic heart disease, rheumatic fever, and Marfan syndrome are also associated with MR

Demographics

• MR can be congenital, present from birth
• More common in women and with advanced age

Signs and Symptoms

• Symptoms depend on degree of valvular dysfunction.
• Mild-to-moderate regurgitation generally does not cause symptoms
• Deviation of heartbeat or point of maximal impulse (PMI)
• Cardiovascular collapse or shock
• Audible systolic murmur at left 4th intercostal space, mid-clavicular line
• Angina pectoris
• Syncope
• Congestive heart failure
• Dyspnea on exertion
• Shortness of breath
• Anginal chest pain that increases with exercise
• Orthopnea
• Fatigue weakness
• Fainting, dizziness with activity
• Palpitations
• Palpable heaves/thrills over precordium
• Arrhythmias, particularly atrial fibrillation
• Endocarditis

Functional Implications

• Severe MR causes progressive shortness of breath and signs of congestive heart failure
• Minimal functional implications and patients may be unaware of reduced cardiovascular capacity until it becomes severe
• MR can cause syncope, chest pain, and heart failure if untreated

Possible Contributing Causes

• Acute rheumatic fever
• MVP: most common cause of MR is mitral valve prolapse (MVP) due to weakening of connective tissue
• Coronary artery disease
• Diabetes mellitus
• Hyperlipoproteinemia
• Hypertension
• Marfan syndrome
• Older age

Differential Diagnosis

• Acute coronary syndrome
• Aortic regurgitation
• Aortic stenosis
• MVP
• Mitral stenosis
• Myocardial infarction dysfunction
• Shock, hypovolemia
• Heart failure
  • Chest x-ray evidence of pulmonary edema
  • Signs and symptoms of right and left heart failure
  • Markedly decreased exercise tolerance
  • Decreased systolic BP during exercise
  • EF < 30 to 40%
  • Disability

Imaging

• Echocardiography
• MRI of the heart
• Chest x-ray
• ECG