A 65-year-old male with a history of hypertension and type 2 diabetes mellitus presents to the emergency department with progressive shortness of breath, especially when lying flat, and a 2-week history of worsening fatigue. He reports swelling in both legs and a dry cough. On examination, his blood pressure is 145/85 mmHg, heart rate is 100 beats per minute, and respiratory rate is 24 breaths per minute. Bilateral pitting edema is noted up to the knees, and there are crackles in both lung bases. Jugular venous distension is also present.

Question: Which of the following findings on this patient’s chest X-ray is most specific for the diagnosis of congestive heart failure?

A) Cardiomegaly
B) Prominent pulmonary vasculature
C) Kerley B lines
D) Blunted costophrenic angles

Answer:

C) Kerley B lines.

Hypertension and Diabetes Mellitus
🧠 (Chronic conditions)
⬇️
Left Ventricular Dysfunction (LV failure)
🧠 (Chronic high BP → ↑ Afterload; Diabetes → Microvascular damage → LV dysfunction)
⬇️
Decreased Cardiac Output
⬇️
Activation of Renin-Angiotensin-Aldosterone System (RAAS)
🧠 (Compensatory mechanism → Fluid retention)
⬇️
Increased Left Ventricular End-Diastolic Pressure (LVEDP)
⬆️
Pulmonary Venous Congestion
🧠 (Fluid backs up into pulmonary circulation)
⬇️
Pulmonary Interstitial Edema
🧠 (Transudation of fluid into lung interstitium)
⬇️
Kerley B Lines
🧠 (Linear, horizontal lines due to thickened interlobular septa caused by edema)
⬇️
Progressive Shortness of Breath, Orthopnea, Bilateral Crackles
🧠 (Fluid in the lungs)
⬇️
Bilateral Pitting Edema, Jugular Venous Distention
🧠 (Systemic venous congestion due to right-sided heart failure)
⬇️
Chest X-ray Findings

• Cardiomegaly 🧠 (Enlarged heart due to LV hypertrophy/dilatation)

• Prominent Pulmonary Vasculature 🧠 (↑ Pulmonary venous pressure)

• Kerley B Lines 🧠 (Specific for CHF)

• Blunted Costophrenic Angles 🧠 (Pleural effusion from fluid accumulation)

Why Other Answers Are Wrong?

A) Cardiomegaly
🧠 Cardiomegaly = Enlarged heart shadow

Cause: Heart failure → Heart enlargement due to chronic pressure/volume overload

🧠 Not specific: Cardiomegaly can occur in many other conditions (e.g., chronic hypertension)

B) Prominent Pulmonary Vasculature

🧠 Cause: Pulmonary venous congestion → ↑ Blood in lungs

🧠 Not specific: Can also be seen in pneumonia, pulmonary hypertension, or fluid overload without CHF

D) Blunted Costophrenic Angles
🧠 Cause: Pleural effusion (fluid buildup in pleural space) → Blunting of the angle

🧠 Not specific: Pleural effusions can occur in infections, malignancies, or trauma

Flashcards

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