MioAtlas
G1: Left-sided valves

Degenerative mitral regurgitation (flail P2)

Severe primary organic mitral regurgitation secondary to spontaneous or degenerative chordal rupture (typically of the P2 scallop of the posterior leaflet in the setting of fibroelastic deficiency or myxomatous degeneration).

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Definition

Severe primary organic mitral regurgitation secondary to spontaneous or degenerative chordal rupture (typically of the P2 scallop of the posterior leaflet in the setting of fibroelastic deficiency or myxomatous degeneration), causing unconstrained systolic eversion of the leaflet free edge into the left atrium, left ventricular volume overload, and progressive left atrial dilation [V1] [V3] [G1-05].

Severity criteria

  • Mild (L): Effective regurgitant orifice area (EROA) < 0.20 cm²; Regurgitant volume (RV) < 30 mL/beat; Regurgitant fraction (RF) < 30 %; vena contracta (VC) < 0.3 cm [V1] [V3].
  • Moderate (M): EROA 0.20–0.39 cm²; RV 30–59 mL/beat; RF 30–49 %; vena contracta (VC) 0.3–0.69 cm [V1] [V3].
  • Severe (G): EROA ≥ 0.40 cm²; RV ≥ 60 mL/beat; RF ≥ 50 %; vena contracta (VC) ≥ 0.7 cm; Presence of flail leaflet or chordal rupture; Systolic flow reversal in pulmonary veins [V1] [V3] [G1-05].

Findings by layer

Hemodynamics

  • Left ventricular volume overload with progressive increase in end-diastolic and end-systolic volumes, with initially hyperdynamic ejection fraction (> 65 %) declining as myocardial contractility fails [V1] [G1-05].
  • Left atrial pressure: Elevated in severe stages, with prominent 'v' wave [V1] [V3].

Rhythm

  • Normal sinus rhythm in initial stages [V1].
  • Atrial fibrillation frequent in advanced chronic stages due to progressive dilation of the mitral annulus and left atrium [V1] [G1-05].

ECG

  • Left atrial enlargement (left atrial enlargement, P mitrale) in sinus rhythm [E1].
  • Left ventricular hypertrophy due to volume overload (left ventricular hypertrophy voltage criteria, prominent R waves in lateral leads) [E1].

Heart sounds and murmurs

  • Holosystolic murmur: High-frequency regurgitant murmur beginning immediately with S1 and encompassing or extending beyond the second heart sound (S2) [V3] [G1-14].
  • Murmur radiation depending on flail leaflet:
    • In chordal rupture of the posterior leaflet (most frequent): Regurgitant jet is directed eccentrically anteromedially toward the interatrial septum and aortic root, so the murmur radiates toward the cardiac base, aortic area, and carotids [V3] [G1-06] [G1-14].
    • In anterior leaflet involvement: Jet is directed toward the posterior left atrial wall and radiates classically to the left axilla and back [V3] [G1-06] [G1-14].
  • First heart sound (S1): Decreased or obscured by the early onset of the murmur [G1-10].
  • Third heart sound (S3): Frequent at the apex due to increased rapid ventricular diastolic filling [G1-12] [V1].

Arterial pulse

  • Brisk, sharp pulse with rapid collapse (pulsus celer et brevis) due to rapid stroke volume ejection into two low-resistance runoff pathways (aorta and left atrium) [B4].

Jugular venous pulse

  • Normal when compensated; elevation of 'v' wave if pulmonary hypertension and secondary tricuspid regurgitation supervene [B3].

Maneuvers

  • Isometric handgrip: Markedly increases holosystolic murmur intensity by raising aortic afterload and LV-LA transmural gradient [B1].
  • Valsalva maneuver (strain phase): Decreases murmur intensity by reducing preload [B1].
  • Squatting: Increases holosystolic murmur intensity [B1].

Simulator severity grades

Simulator severity grades: Mild, Moderate, Severe
Baseline rhythm: Normal Sinus Rhythm

Also known as: Flail mitral leaflet · Degenerative mitral regurgitation · Mitral valve chordal rupture · Primary mitral regurgitation · DMR

Other pathologies in this group

Related clinical comparisons

Sources

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  2. [B3] The jugular venous pressure revisited . Cleve Clin J Med (2013) . DOI: 10.3949/ccjm.80a.13039 PubMed: 24085809
  3. [B4] The Carotid Pulse . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250154
  4. [E1] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191097 PubMed: 19228820
  5. [G1-05] Clinical outcome of mitral regurgitation due to flail leaflet . N Engl J Med (1996) . DOI: 10.1056/NEJM199611073351902 PubMed: 8875918
  6. [G1-06] The mitral apparatus. Functional anatomy of mitral regurgitation . Circulation (1972) . DOI: 10.1161/01.cir.46.2.227 PubMed: 5046018
  7. [G1-10] The First Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250175
  8. [G1-12] The Third Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250184
  9. [G1-14] Systolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250186
  10. [V1] 2025 ESC/EACTS Guidelines for the management of valvular heart disease . Eur Heart J (2025) . DOI: 10.1093/eurheartj/ehaf194 PubMed: 40878295
  11. [V2] 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines . Circulation (2021) . DOI: 10.1161/CIR.0000000000000923 PubMed: 33332150
  12. [V3] Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation: A Report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance . J Am Soc Echocardiogr (2017) . DOI: 10.1016/j.echo.2017.01.007 PubMed: 28314623