Internal Medicine · Year 3 · from Internal Medicine
Case 1: Heart Failure with Peripheral Edema
Patient Presentation
A 72-year-old woman with a history of hypertension and coronary artery disease presents with progressive bilateral lower extremity swelling over the past 3 weeks. She reports orthopnea requiring 3 pillows to sleep and has gained 8 pounds over the past month. She denies chest pain but notes worsening dyspnea on exertion, now occurring with minimal activity like walking to the bathroom.
Vital Signs
- Blood Pressure: 158/92 mmHg
- Heart Rate: 88 bpm
- Respiratory Rate: 20/min
- Oxygen Saturation: 93% on room air
- Temperature: 36.8°C
Physical Examination
- General: Mild respiratory distress at rest
- Cardiovascular: JVD to angle of jaw at 45°, S3 gallop, displaced PMI
- Pulmonary: Bibasilar crackles extending one-third up lung fields
- Abdomen: Hepatomegaly, positive hepatojugular reflux
- Extremities: 3+ pitting edema to mid-thigh bilaterally
Initial Workup
- BNP: 1,850 pg/mL (normal <100 pg/mL)
- Creatinine: 1.4 mg/dL (baseline 1.0)
- Chest X-ray: Cardiomegaly, pulmonary vascular congestion, bilateral pleural effusions
- ECG: Sinus rhythm, left ventricular hypertrophy, Q waves in V1-V3
Clinical Image
Figure 1: Pitting edema of the lower extremity demonstrating characteristic skin indentation after pressure application, consistent with increased capillary hydrostatic pressure.
Image Source: Educational illustration for teaching purposes.
Questions
- What is the primary mechanism of edema in this patient?
- A) Decreased plasma oncotic pressure
- B) Increased capillary hydrostatic pressure
- C) Lymphatic obstruction
- D) Increased capillary permeability
- Which of the following findings best indicates elevated right-sided filling pressures?
- A) S3 gallop
- B) Bibasilar crackles
- C) Jugular venous distension
- D) Displaced PMI
- What is the most appropriate initial diuretic therapy?
- A) Oral hydrochlorothiazide 25 mg daily
- B) IV furosemide 40 mg
- C) Oral spironolactone 25 mg daily
- D) Oral metolazone 5 mg daily
- Calculate this patient's estimated daily sodium intake if she is producing 1.5 L of urine with urine sodium of 80 mEq/L and is in steady state.
- What findings on physical examination help distinguish cardiac edema from hepatic edema?
Answers
- B) Increased capillary hydrostatic pressure - Heart failure leads to venous congestion with elevated capillary hydrostatic pressure, causing fluid transudation into the interstitium according to Starling forces.
- C) Jugular venous distension - JVD directly reflects elevated central venous pressure and right-sided filling pressures. S3 and displaced PMI indicate left ventricular dysfunction, while crackles indicate pulmonary congestion.
- B) IV furosemide 40 mg - Intravenous loop diuretics are first-line for acute decompensated heart failure with volume overload. IV administration ensures reliable absorption despite potential gut edema.
- Calculation: Urine sodium excretion = 1.5 L × 80 mEq/L = 120 mEq/day. In steady state, intake ≈ output, so sodium intake is approximately 120 mEq or about 2,760 mg (120 × 23 mg/mEq) of sodium per day, or approximately 7 grams of salt.
- Distinguishing features:
- Cardiac: JVD, S3 gallop, displaced PMI, pulmonary crackles, hepatojugular reflux
- Hepatic: Ascites out of proportion to peripheral edema, spider angiomata, palmar erythema, gynecomastia, caput medusae, splenomegaly
- Both may have hepatomegaly, but cardiac causes have pulsatile hepatomegaly