Harvey's Garden

Mitral regurgitation

2 min read

Epidemiology

Etiology

  • Acute: Papillary muscle rupture (post-MI), Infective Endocarditis (IE), Chordae tendineae rupture (MVP, trauma).
  • Chronic Primary: Mitral Valve Prolapse (MVP - most common in US) c, Rheumatic Heart Disease (developing countries), Myxomatous degeneration.
  • Chronic Secondary (Functional): LV dilatation (HFrEF), Ischemic cardiomyopathy (tethers leaflets).
    • This results in hypokinesis and outward displacement of the papillary muscle, creating increased tension on the attached chordae tendineae and preventing complete closure of the corresponding mitral valve cusp. t

Pathophysiology

Clinical features

  • Auscultation
    • S3 heart sound in advanced stages of disease
      • Indication of severity
      • vs S2-opening snap interval in Mitral stenosis, also a indication of severity
    • Holosystolic murmur (high-pitched, blowing)
      • Radiates to the left axilla and heard best over the apex (5th intercostal space at the left midclavicular line)
      • Intensity can be increased by increasing preload (e.g., leg raise) or afterload (e.g., handgrip) due to increased regurgitation.

Diagnostics

  • Initial/Screening: Transthoracic echocardiogram (TTE) to evaluate regurgitant jet, etiology, LV/LA size, and LV ejection fraction (LVEF).
  • Confirmatory/Pre-op: Transesophageal echocardiogram (TEE) if TTE is suboptimal, or for surgical planning/guidance.
  • Key Labs/Imaging:
    • ECG: LA enlargement, LV hypertrophy, atrial fibrillation (A-fib).
    • CXR: LA/LV enlargement, pulmonary vascular congestion/edema.

Treatment

  • Acute MR:
    1. Medical Stabilization: O2, vasodilators (e.g., nitroprusside to ↓ afterload and ↑ forward flow), diuretics.
    2. Hemodynamic Collapse: Intra-aortic balloon pump (IABP) to bridge to surgery.
    3. Definitive: Urgent/emergent surgical repair or replacement.
  • Chronic Primary MR:
    1. Symptomatic pts: Mitral valve repair (preferred) or replacement.
    2. Asymptomatic pts: Surgery indicated if LVEF 30-60% and/or LV end-systolic dimension (LVESD) 40 mm. (Note: LVEF > 60% is normal in MR due to unloading into LA; LVEF < 60% indicates LV failure due to chronic volumn overload). c
  • Chronic Secondary (Functional) MR:
    1. First-line: Guideline-directed medical therapy (GDMT) for heart failure (ACEi/ARNI, beta-blockers, MRA, SGLT2i).
    2. Refractory: Transcatheter edge-to-edge repair (TEER, e.g., MitraClip) in highly selected pts with severe symptoms despite GDMT.

Graph View

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