factor.(c)The patient’s cardiac biomarkers are also positive and consistent
with the ECG. (e)Alcohol use at this age will not lead to an acute MI.
39.The answer is b. (Tintinalli, pp 378-81.) The patient has
hypertrophic cardiomyopathy,which is characterized by left ventricular
hypertrophy without associated ventricular dilation. The hypertrophy is
usually asymmetric, involving the septum to a greater extent than the free
wall. Patients are at increased risk of dysrhythmias and sudden death.
Syncope is usually exertion-related and is caused by a dysrhythmia or a
sudden decrease in cardiac output. The murmur associated with hyper-
trophic cardiomyopathy is a prominent systolic ejection murmurheard
along the left sternal boarder and at the apex with radiation to the axilla.
The murmur is a result of LV outflow obstruction and mitral regurgitation.
It is increasedwith maneuvers that decrease left ventricular end-diastolic
volume, such as the Valsalva maneuver, sudden standing, and exercise.
(a)The Valsalva maneuver will decrease the duration of all other mur-
murs except mitral valve prolapse and hypertrophic cardiomyopathy. (c, d,
and e)are incorrect as described in the explanation above.
40.The answer is a.(Rosen, pp 1135-1136.)The patient presents with a
pericardial effusionprobably secondary to her metastatic breast cancer.
Pericardial effusion is often asymptomatic but with accumulating fluid can
cause chest pain, shortness of breath, cough, and fever. Ultimately, it can lead
to cardiac tamponade, which develops in up to 10% of all cancer patients.
The ECG classically shows low-voltage complexesand, rarely, electrical
alternans.Treatment of nontraumatic pericardial effusion and tamponade is
pericardiocentesis to remove the fluid.
(b)Increased voltage on an ECG typically represents ventricular
hypertrophy. (c)ST depression is seen in cardiac ischemia, and reciprocal
changes in acute MI. (d)ST elevation is seen in acute MI, pericarditis, and
early repolarization. (e)T-wave inversion is seen in cardiac ischemia.
41.The answer is a.(Tintinalli, pp 386-391.)In the absence of a con-
traindication and a pretest probability that exceeds 50%,empiric heparin
therapy should be administered.The patient has a high pretest probabil-
ity for a PE with the following suggestive features: malignancy, tachycardia,
tachypnea, suspected DVT, pleuritic chest pain, and dyspnea. Although
heparin has no intrinsic fibrinolytic effect, it has an immediate effect on
thrombin inhibition, thus preventing extension of the PE.
Chest Pain and Cardiac Dysrhythmias Answers 45