CHAPTER 9 • CARDIOVASCULAR INTEGRATION, ADAPTATION, AND PATHOPHYSIOLOGY
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10. Compared to the maximal exercise
responses of a normal subject, a patient
with moderate-to-severe heart failure
during maximal exercise will have a
a. Lower arterial pressure.
b. Lower arterial-venous oxygen
extraction.
c. Higher ejection fraction.
d. Similar maximal oxygen consumption.
11. A patient with a history of mild hyperten-
sion has recently been diagnosed with left
ventricular systolic dysfunction associated
with dilated cardiomyopathy. In addition
to a diuretic, the patient is also prescribed
a mixed arterial-venous dilator (e.g., an
ACE inhibitor). The rationale for adding
the vasodilator is that it will increase
a. Stroke volume by increasing preload.
b. Ventricular afterload by reducing
preload.
c. Ventricular ejection fraction by
increasing stroke volume.
d. Ventricular end-systolic volume by
increasing stroke volume.
12. A patient is diagnosed with moderately
severe aortic valve regurgitation. In the
absence of ventricular failure, which of
the following changes is associated with
this valve defect?
a. Aortic diastolic pressure is
increased.
h. Aortic systolic pressure is decreased.
c. Left ventricular stroke volume into
the aorta is increased.
d. Left ventricular preload is
decreased.
13. A patient is diagnosed with mitral
valve stenosis with no evidence of
systolic dysfunction. This patient will
likely have
a. A systolic murmur,
h. Elevated left atrial pressure.
c. Increased left ventricular end-diastolic
pressure.
d. Reduced left ventricular ejection
fraction.
ANSWERS TO REVIEW QUESTIONS
1.
The correct answer is “d” because heart
rate is increased during exercise through
activation of sympathetic adrenergic
nerves and inhibition of vagal (parasym-
pathetic) nerves on the sinoatrial node.
Choice “a” is incorrect because arterial
pulse pressure increases during moder-
ate exercise because of the increase in
stroke volume. Choice “b” is incorrect
because cutaneous vasodilation occurs
during exercise to facilitate heat loss
from the body. Choice “c” is incorrect
because systemic vascular resistance falls
owing to vasodilation in the active skel-
etal muscle.
2.
The correct answer is “d” because the
muscle pump system facilitates venous
return, which maintains or elevates ven-
tricular filling pressures. Choice “a” is
incorrect because a decrease in central
venous pressure would decrease stroke
volume. Choice “b” is incorrect because
an increase in heart rate, with no other
compensatory changes, decreases stroke
volume. Choice “c” is incorrect because
the rate of ventricular relaxation (lus-
itropy) increases during exercise owing
to sympathetic influences, which aids
ventricular filling and enhances stroke
volume.
3.
The correct answer is “b” because arteri-
al pressure increased; therefore, cardiac
output must have increased more than
systemic vascular resistance decreased
because mean arterial pressure is
approximately the product of cardiac
output and systemic vascular resistance.
Choice “a” is incorrect because cardiac
output (the product of heart rate and
stroke volume) increased from 5.6 to
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