01-13-2009, 03:03 PM
A 2-month-old girl is brought to the physician because of a
2-week history of progressive difficulty breathing and poor feeding. She
has had rapid and labored breathing and sweating during feedings. There
is no history of fever or viral illness. Her temperature is 37 C (98.6
F), blood pressure is 80/60 mm Hg, pulse is 130/min, and respirations
are 40/min. Bilateral crackles are heard at both lung bases. A grade
4/6 holosystolic murmur is heard along the left sternal border; the
precordium is hyperdynamic. The liver edge is palpated 4 cm below the
right costal margin. An x-ray film of the chest shows cardiomegaly and
pulmonary congestion. Which of the following is the most likely
underlying mechanism for this child's condition?
A) Decreased systemic vascular resistance
B) Increased pulmonary vascular resistance
C) Increased systemic vascular resistance
D) Intracardiac left-to-right shunt
E) Intracardiac right-to-left shunt
2-week history of progressive difficulty breathing and poor feeding. She
has had rapid and labored breathing and sweating during feedings. There
is no history of fever or viral illness. Her temperature is 37 C (98.6
F), blood pressure is 80/60 mm Hg, pulse is 130/min, and respirations
are 40/min. Bilateral crackles are heard at both lung bases. A grade
4/6 holosystolic murmur is heard along the left sternal border; the
precordium is hyperdynamic. The liver edge is palpated 4 cm below the
right costal margin. An x-ray film of the chest shows cardiomegaly and
pulmonary congestion. Which of the following is the most likely
underlying mechanism for this child's condition?
A) Decreased systemic vascular resistance
B) Increased pulmonary vascular resistance
C) Increased systemic vascular resistance
D) Intracardiac left-to-right shunt
E) Intracardiac right-to-left shunt
