into malignancy-related or nonmalignancy-related. Malignancies of primary
adenocarcinoma or brain malignancy are the most likely to cause thrombosis.
Some causes of nonmalignancy-related thrombosis are estrogen use, preg-
nancy, antiphospholipid syndromes, factor V Leiden mutation, and protein C
and S deficiencies. Immobility such as paralysis, debilitating diseases, or recent
surgery or trauma also place patients at risk.
29.The answer is e.(Rosen, p 1155.)Theclassic triad of aortic stenosis
is dyspnea, chest pain, and exertional syncope.Syncope is a result of
either inadequate cerebral perfusion or occasional dysrhythmias. The classic
auscultory finding is a harsh systolic ejection murmurthat is best heard
in the second right intercostal space with radiation to the carotid arteries.
Syncope in the setting of a new systolic murmur always should raise the
suspicion for aortic stenosis as the etiology. The ECG usually reveals left
ventricular hypertrophy.
(a)Asystole denotes the lack of electrical activity of the heart. Individ-
uals usually don’t recover from an asystolic cardiac arrest. (b)Brugada syn-
drome is caused by an autosomal dominant trait resulting in total loss of
function of the cardiac sodium channel or in acceleration of recovery from
sodium channel activation. It leads to syncope and may cause sudden car-
diac death secondary to a polymorphic ventricular tachycardia. It is associ-
ated with a distinctive ECG pattern of downsloping ST-segment elevation
in leads V 1 to V 3 with a right bundle-branch block pattern. (c)The subcla-
vian steal syndrome is a rare but important cause of syncope. The syn-
drome results from occlusion of the proximal subclavian artery and the
development of retrograde flow to the subclavian artery from the vertebral
artery. (d)A PE that causes syncope usually causes the individual to have
unstable vital signs secondary to obstruction of a major vessel.
30.The answer is c.(Tintinalli, pp 333-342.)The patient’s presentation is
concerning for a cardiac cause of his chest pain. Chest pain radiating to the
left arm that is associated with shortness of breath is a classic presentation
of ACS. On arrival to the ED, the patient should be placed on a monitor,
receive oxygen by nasal cannula, have an IV placed and blood sent to the
laboratory, and an ECG performed. Any abnormalities in his vital signs
should also be addressed. Serum cardiac markers are useful in detecting
MI. Troponin T and I appear in the serum within 6 hours of symptom onset
and remain elevated for 1 to 2 weeks. Troponin Iis the most specific car-
diac markeravailable (almost 100%) and peaks between 12 and 18 hours.
Chest Pain and Cardiac Dysrhythmias Answers 39