A 74-year-old woman is admitted to the hospital with a 4-week history of progressively wor… — USMLE Step 2 CK

A 74-year-old woman is admitted to the hospital with a 4-week history of progressively worsening exertional dyspnea, increased abdominal girth, and bilateral lower extremity swelling. She has a history of chronic obstructive pulmonary disease (COPD), essential hypertension, and obesity ( $BMI$ 36 kg/m $^2$ ). Her current medications include amlodipine, lisinopril, and a tiotropium inhaler. Blood pressure is 155/92 mm Hg, pulse is 92/min, and respirations are 20/min. Pulse oximetry is 94% on room air. Jugular venous pressure is estimated at 12 cm $H_2O$ and shows a prominent v wave. Lung auscultation reveals distant breath sounds with prolonged expiration and scattered end-expiratory wheezes. Cardiac examination shows a regular rhythm, a right-sided S3 gallop, and a 3/6 holosystolic murmur at the left lower sternal border that increases with inspiration. The abdomen is distended with shifting dullness, and there is 3+ pitting edema of the lower extremities extending to the thighs.

Laboratory testing reveals the following:
Brain natriuretic peptide (BNP): 650 pg/mL
Thyroid-stimulating hormone (TSH): 1.2 $\mu U/mL$ (normal: 0.4-4.0 $\mu U/mL$ )
Free thyroxine (T4): 0.7 ng/dL (normal: 0.9-1.7 ng/dL)
Arterial blood gas (room air): pH 7.32, $pCO_2$ 55 mm Hg, $HCO_3^-$ 28 mEq/L

An echocardiogram shows a normal-sized left ventricle with an ejection fraction of 65%. The left atrium is severely enlarged (volume index 48 mL/m $^2$ ). The right ventricle is dilated and hypokinetic. Estimated pulmonary artery systolic pressure is 70 mm Hg. Tissue Doppler imaging of the mitral annulus shows an $E/e'$ ratio of 18 (normal $< 8$ ).

Which of the following is the most appropriate next step in management?

Intravenous furosemideAnswer
B
Inhaled albuterol and oral prednisone
C
Initiation of oral sildenafil
D
Initiation of oral levothyroxine
E
Intravenous sodium bicarbonate

Answer

Intravenous furosemide

The correct answer is intravenous furosemide. This patient is presenting with acute decompensated heart failure with preserved ejection fraction (HFpEF). Although her ejection fraction is normal (65%), she has definitive echocardiographic evidence of chronically elevated left ventricular filling pressures, namely a severely enlarged left atrium and an

E/e'

ratio greater than 15. This left-sided venous congestion has led to WHO Group 2 pulmonary hypertension, which in turn has caused right ventricular dilation and right heart failure (manifesting as elevated jugular venous pressure, a tricuspid regurgitation murmur, ascites, and edema). The wheezing is likely 'cardiac asthma' due to peribronchial edema rather than a primary COPD flare. The immediate priority is to reduce her volume overload and left-sided filling pressures with intravenous loop diuretics (e.g., furosemide).

Step-by-Step Solution

Analyze the primary clinical signs and symptoms.

The patient exhibits classic signs of severe right-sided heart failure (elevated jugular venous pressure with a prominent v wave, right-sided S3, ascites, and marked peripheral edema).

To establish the predominant clinical syndrome requiring intervention.

Interpret the echocardiogram findings to determine the etiology.

Despite a normal ejection fraction of 65%, the severely enlarged left atrium and elevated

E/e'

ratio (18) are diagnostic of elevated left ventricular filling pressures (Heart Failure with Preserved Ejection Fraction).

To differentiate primary right heart failure (Cor Pulmonale) from right heart failure secondary to left-sided heart disease.

Evaluate the secondary laboratory derangements.

The thyroid panel indicates euthyroid sick syndrome (low free T4, normal TSH) which requires no treatment. The arterial blood gas shows an acute-on-chronic respiratory acidosis consistent with her baseline COPD, which does not require bicarbonate.

To rule out contributing pathologies that might require specific, immediate therapy and to avoid inappropriate treatments.

Select the most appropriate immediate intervention.

Intravenous furosemide is chosen to initiate diuresis.

Loop diuretics reduce the volume overload and left-sided filling pressures that are driving the WHO Group 2 pulmonary hypertension and subsequent right heart failure.

Key Concept

Patients with Heart Failure with Preserved Ejection Fraction (HFpEF) can present with isolated right heart failure symptoms due to WHO Group 2 pulmonary hypertension; immediate management centers on diuresis rather than pulmonary vasodilators or COPD optimization.

Estimated Time:2m 0s

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