Master the board step 3

Master the Boards: USMLE Step 3
Congestive Heart Failure (CHF)
The mechanism that matters for congestive failure has to do with the difference
in treatment between systolic dysfunction with a low ejection fraction
and diastolic dysfunction and a normal ejection fraction. There is no clear
way to distinguish systolic from diastolic dysfunction from symptoms alone.
Clues in the history are hypertension, valvular heart disease, and myocardial
infarction.
S3: Splash
S4: Bang
CHF presents with shortness of breath, particularly on exertion, in a person
with any of the following:
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Edema
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Rales on lung examination
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Ascites
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Jugular venous distention
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S3 gallop
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Orthopnea
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Paroxysmal nocturnal dyspnea
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Fatigue
Basic Science Correlate
Mechanism of Rales
Increased hydrostatic pressure develops in the pulmonary capillaries from left
heart pressure overload. This causes transudation of liquid into the alveoli.
During inhalation, the alveoli open with a “popping” sound referred to as rales.
Pulmonary Edema
A 63-year-old woman comes to the emergency department with acute, severe
shortness of breath; rales on lung exam; S3 gallop; and orthopnea. Which of the
following is the most important step?
a. Chest x-ray
b. Oxygen, furosemide, nitrates, and morphine
c. Echocardiogram
d. Digoxin
e. ACE inhibitors
f. Carvedilol
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