Cardiothoracic Surgery: Mitral Regurgitation (MR)

Mitral Regurgitation (MR)

Definition

  • Definition: Inadequate Systolic Closure of the Mitral Valve
  • A Portion of Stroke Volume Regurgitates from the Left Ventricle Back into the Left Atrium
    • Causes Left Ventricle Hypertrophy & Pulmonary Hypertension

Causes

  • Mitral Valve Prolapse (MVP)
  • Myxomatous Degeneration
  • Redundant Leaflets
  • Rheumatic Heart Disease
  • Infective Endocarditis
  • Trauma
  • Cardiomyopathy

Symptoms

  • Exertional Dyspnea
  • Fatigue
  • Atrial Fibrillation
  • Congestive Heart Failure
  • *Symptoms are Uncommon Until Disease is Severe

Diagnosis

  • Diagnosis: Echocardiogram
  • Severity:
  Mild Moderate Severe
Vena Contracta Width < 0.30 cm 0.30-0.69 cm ≥ 0.70 cm
Regurgitant Volume < 30 mL/Beat 30-59 mL/Beat ≥ 60 mL/Beat
Regurgitant Fraction < 30% 30-49% ≥ 50%
Regurgitant Orifice Area < 0.20 cm2 0.20-0.39 cm2 ≥ 0.40 cm2
  • Stage:
    • Stage A: At Risk for MR or Mild MR
    • Stage B: Moderate MR
    • Stage C: Asymptomatic Severe MR
      • Stage C1: LV Ejection Fraction Normal (≥ 60%)
      • Stage C2: LV Ejection Fraction Reduced (< 60%)
    • Stage D: Symptomatic Severe MR

General Management

  • Asymptomatic: Monitoring for Disease Progression
    • Medical Management of Heart Failure & Hypertension
  • Symptomatic: Mitral Valve Repair
    • Generally Preferred Over Replacement (Better Function & Lower Mortality)

Mitral Valve Repair Indications

  • Severe MR if:
    • Symptomatic & LVEF > 30%
    • Symptomatic & LVEF ≤ 30% (Only if High Likelihood of Successful Repair)
    • Undergoing Cardiac Surgery for Other Interventions
    • LVEF 30-60% or LVESD ≥ 40%