12-14-2009, 05:23 AM
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
First the diagnosis., then mechanism
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
First the diagnosis., then mechanism