Cardiovascular · Year 1 · from Cardiovascular

Case 1: Lower Extremity Edema - Heart Failure

Patient Presentation

Demographics: 68-year-old male

Chief Complaint: Progressive leg swelling and shortness of breath for 3 weeks

History of Present Illness: A 68-year-old male with history of ischemic cardiomyopathy (LVEF 25%, prior MI 5 years ago), hypertension, and type 2 diabetes presents with progressive bilateral leg swelling over 3 weeks. He reports increasing shortness of breath with exertion and now with minimal activity. He has gained 15 pounds in the past month despite eating less. He sleeps with 4 pillows (orthopnea) and wakes up gasping for air (PND). He admits to dietary indiscretion (high sodium meals) and running out of furosemide 2 weeks ago.

Physical Examination:

• Vital Signs: BP 145/92 mmHg, HR 95 bpm, RR 24/min, SpO2 91% on room air
• General: Dyspneic at rest, mild distress
• Cardiovascular:
• JVP elevated to 16 cm (markedly elevated)
• S3 gallop present
• Laterally displaced PMI
• Lungs: Bilateral crackles to mid-lung fields
• Abdomen: Distended, hepatomegaly, positive hepatojugular reflux
• Extremities: 3+ bilateral pitting edema to thighs, tight, shiny skin

Workup

• Labs:
• BNP: 1,850 pg/mL (markedly elevated)
• Creatinine: 1.8 mg/dL (baseline 1.2)
• Sodium: 128 mEq/L (dilutional hyponatremia)
• Hemoglobin: 10.8 g/dL
• Chest X-ray: Cardiomegaly, bilateral pleural effusions, Kerley B lines, pulmonary vascular congestion
• Echocardiogram: LVEF 20% (worse than prior), dilated LV, moderate MR, elevated PASP 55 mmHg

Diagnosis

Acute decompensated heart failure with volume overload - Starling forces imbalance

Microcirculation and Starling Forces Correlation:

Starling Equation: Net Filtration = Kf [(Pc - Pi) - σ(πc - πi)]

Where:

• Kf = Capillary filtration coefficient
• Pc = Capillary hydrostatic pressure
• Pi = Interstitial hydrostatic pressure
• πc = Capillary oncotic pressure
• πi = Interstitial oncotic pressure
• σ = Reflection coefficient

In heart failure, edema develops because:

1. ↑ Capillary hydrostatic pressure (Pc):

• Right heart failure → elevated venous pressure → transmitted to capillaries
• Sodium/water retention (RAAS activation) increases intravascular volume

1. Neurohormonal activation:

• Renin-angiotensin-aldosterone system (RAAS) → Na+/H2O retention
• ADH release → water retention (dilutional hyponatremia)

1. Lymphatic capacity exceeded:

• Normally lymphatics drain filtered fluid
• Overwhelmed when filtration rate exceeds drainage capacity

Starling forces balance:

Result: Net filtration > lymphatic drainage → interstitial edema

Treatment

1. IV loop diuretics: Furosemide 80 mg IV (double home oral dose)
2. Strict I/O monitoring: Target negative 1-2 L/day
3. Daily weights: Target 1-2 kg weight loss per day
4. Sodium restriction: <2 g/day
5. Fluid restriction: <1.5 L/day (for hyponatremia)
6. Optimize neurohormonal blockade: ACE-I, beta-blocker, MRA
7. Consider ultrafiltration if diuretic resistant
8. Compression stockings after acute phase

Clinical Image

Image Description: Photograph demonstrating pitting edema of the lower extremity in a patient with heart failure. Note the depression that remains after finger pressure is applied, indicating fluid accumulation in the interstitial space.

Source: Wikimedia Commons - Pitting edema License: CC BY-SA 4.0 URL: https://commons.wikimedia.org/wiki/File:Pitting_edema.jpg

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