Cardiovascular · Year 1 · from Cardiovascular

Case 2: Mitral Regurgitation with S3 Gallop

Patient Presentation

Demographics: 55-year-old female

Chief Complaint: Progressive shortness of breath and leg swelling for 2 months

History of Present Illness: A 55-year-old female with history of rheumatic fever as a child presents with 2 months of progressive dyspnea, now occurring with minimal exertion. She also notes orthopnea (sleeps with 3 pillows), paroxysmal nocturnal dyspnea, and bilateral leg swelling. She has experienced fatigue and decreased exercise tolerance.

Physical Examination:

  • Vital Signs: BP 118/68 mmHg, HR 92 bpm (irregular), RR 22/min, SpO2 94% on room air
  • General: Appears fatigued, mild respiratory distress
  • Cardiovascular:
  • JVP elevated to 14 cm
  • PMI: Diffuse, laterally displaced, hyperdynamic
  • Auscultation: Holosystolic (pansystolic) murmur at apex radiating to axilla
  • S1: Diminished
  • S3 gallop present (low-pitched sound in early diastole)
  • Irregularly irregular rhythm (atrial fibrillation)
  • Lungs: Bibasilar crackles
  • Extremities: 2+ bilateral pitting edema

Workup

  • ECG: Atrial fibrillation with LVH, left atrial abnormality
  • Chest X-ray: Cardiomegaly, pulmonary vascular congestion, Kerley B lines
  • Echocardiogram:
  • Severe mitral regurgitation (rheumatic etiology with leaflet thickening and restriction)
  • Dilated left atrium (5.8 cm)
  • Dilated left ventricle (LVEDD 6.5 cm)
  • LVEF: 50% (may be falsely preserved due to unloading into LA)
  • Moderate pulmonary hypertension

Diagnosis

Severe chronic mitral regurgitation (rheumatic) with heart failure and atrial fibrillation

Cardiac Cycle Correlation:

  • Holosystolic murmur: Occurs throughout systole because the pressure gradient between LV and LA exists from mitral valve closure to opening
  • S3 gallop (ventricular gallop): Occurs during rapid ventricular filling phase of diastole; indicates volume overload and dilated, compliant LV
  • Diminished S1: Due to incomplete mitral valve closure
  • Hyperdynamic PMI: Reflects volume-overloaded LV
  • Wiggers diagram correlation: During systole, blood regurgitates into LA (normally at low pressure), creating a large v-wave in LA pressure tracing

S3 timing: Occurs 120-180 ms after S2, during the rapid filling phase when blood rushes into the dilated ventricle

Treatment

  1. Diuretics for volume overload (furosemide)
  2. ACE inhibitor or ARB for afterload reduction
  3. Rate control for atrial fibrillation (beta-blocker or digoxin)
  4. Anticoagulation for atrial fibrillation (warfarin or DOAC)
  5. Surgical mitral valve repair or replacement indicated for severe symptomatic MR
  6. Referral to cardiac surgery

Clinical Image

Image Description: Color Doppler echocardiogram showing severe mitral regurgitation with a large regurgitant jet extending deep into the left atrium during systole. The jet represents abnormal blood flow from left ventricle to left atrium through the incompetent mitral valve.

Source: Wikimedia Commons - Mitral regurgitation echocardiogram License: CC BY-SA 4.0 URL: https://commons.wikimedia.org/wiki/File:Mitral_regurgitation_color_doppler.jpg

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