Internal-Medicine

Answers: 9–28 25
18. (A) The myxoma is a solitary globular or polypoid
tumor varying in size from that of a
cherry to a peach. About 75% are found in the
left atrium, and most of the remainder in the
right atrium. The clinical presentation is with
one or more of the classical triad of constitution
symptoms (fatigue, fever, anemia),
embolic events, or obstruction of the valve
orifice. (Fuster, pp. 2081–2082)
19. (A) Diltiazem and verapamil may be of help in
both acute paroxysms of atrial flutter and
chronic management. The other choices have
no effect on the AV node to slow down flutter,
and atropine accelerates AV conduction. At
times, catheter ablation of the flutter pathway
is required in chronic atrial flutter. Surgical
ablation is reserved for cases where other surgical
interventions are required. (Fuster, p. 844)
20. (C) Exercise electrocardiography represents an
increasingly popular noninvasive method for
early detection of latent ischemic heart disease.
As with other diagnostic tests, the exercise ECG
is of most clinical value when the pretest probability
of disease is moderate (i.e., 30–70%). In
men over 40 and women over 50 who plan to
start vigorous exercise, use of exercise ECG is
possibly, but not definitely, supported by the
evidence (class IIb). (Fuster, pp. 477–478)
21. (D) Contrast media used in cardiac catheterization
may result in renal impairment. The
group at highest risk includes diabetics with
renal disease and those with preexisting renal
failure. Good hydration is essential. Other manifestations
of contrast media include nausea
and vomiting (common), and anaphylactoid
reactions characterized by low-grade fever,
hives, itching, angioedema, bronchospasm, and
even shock. Side effects are reduced with the
use of new low osmolality contrast media.
(Fuster, p. 489)
22. (E) Pericarditis in clinical practice is commonly
idiopathic and frequently assumed to be of possible
viral origin. Coxsackieviruses are a
common cause, but herpesviruses are not.
Although TB, rheumatic fever, and MI can
cause pericarditis, they are unlikely in this case.
(Fuster, p. 1979)
23. (C) Left-heart catheterization is a more accurate
measurement, but involves a slightly increased
risk. End-expiratory PA diastolic pressure is
very close (2–4 mm) to wedge pressure as well.
A discordance between wedge pressure and
PA diastolic pressure suggests the presence of
pulmonary hypertension. (Fuster, p. 512)
24. (C) Aortic dissection is a medical emergency
requiring prompt attention. Other cardiac and
pulmonary causes of chest pain can be quickly
ruled out with ECG and CXR. CT scan of the
chest is sensitive (93–100%) in ruling out dissection.
Transesophageal echocardiography is
equally as sensitive but not a transthoracic
echo. (Fuster, pp. 2312–2313)
25. (A) This is characteristic of an atrial septal
defect. Pulmonary blood flow is greater
because of increased blood flow from the right
atrium, which receives blood from the vena
cava and left atrium. (Fuster, pp. 1797–1798)
26. (B) Angina or infarction in young patients
should prompt the physician to consider congenital
coronary artery anomaly or congenital
coronary artery aneurysm. Acquired coronary
artery aneurysm can be caused by atherosclerosis,
trauma, angioplasty, atherectomy, vasculitis,
mycotic emboli, Kawasaki syndrome,
or arterial dissection. (Fuster, p. 1178)
27. (D) This pulse is seen in aortic regurgitation.
The pressure in diastole is usually 50 mm
Hg or lower. This is known as a water hammer
or Corrigan’s pulse. A bisferiens pulse (in
the bisferiens wave form there are two pressure
peaks) may be present as well. Systolic
blood pressure is elevated. (Fuster, p. 1654)
28. (B) Digoxin toxicity may cause any dysrhythmia.
Classically, dysrhythmias that are associated
with increased automaticity and decreased
AV conduction occur (i.e., paroxysmal atrial
tachycardia with 2:1 block, accelerated junctional
rhythm, or bidirectional ventricular tachycardia
[torsade de pointes]). Sinus bradycardia