24.The answer is b.(Rosen, pp 1130-1133.)The classic presentation of
pericarditisincludeschest pain, a pericardial friction rub, and ECG
abnormalities. A prodrome of fever and myalgias may occur. Pericarditis
chest pain is usually substernal and varies with respiration. It is classically
sharp or pleuritic in character. It is typically relieved by sitting forward and
worsened by lying down or swallowing.The physical examination hall-
mark of acute pericarditis is the pericardial friction rub.The earliest ECG
changes are seen in the first few hours to days of illness and include diffuse
ST-segment elevationseen in leads I, II, III, aVL, aVF, and V 2 to V 6. Most
patients with acute pericarditis will have concurrent PR-segment depression.
The mainstay of treatment includes supportive care with anti-inflammatory
medications (eg, NSAIDs). The use of corticosteroids is controversial. An
echocardiogram should be performed to rule out a pericardial effusion and
tamponade.
(a)PE can present with substernal chest pain that is sharp in nature
and worse with inspiration. However, the patient doesn’t exhibit any risk
factors for a PE (c and d).It is very important to be able to differentiate an
acute MI from acute pericarditis because thrombolytic therapy is con-
traindicated in pericarditis as it may precipitate hemorrhagic tamponade.
Unlike the ECG in an acute MI, the ST elevations in early pericarditis are
concave upward rather than convex upward. Subsequent tracings do not
evolve through a typical MI pattern and Q waves do not appear. (e)Antibi-
otics are not routinely used to treat pericarditis.
25.The answer is a.(Rosen, pp 1019-1020.)The earliest ECG finding
resulting from an AMI is the hyperacute T wave,which may appear min-
utes after the interruption of blood flow. The hyperacute T wave, which is
short-lived, evolves to progressive elevation of ST segments.In general,
Q wavesrepresent established myocardial necrosis and usually develop
within 8 to 12 hours after a ST-elevation MI, though they may be noted as
early as 1 to 2 hours after the onset of complete coronary occlusion.
26.The answer is d.(Rosen, pp 1120-1128.)The patient has acute CHF
exacerbationwithacute pulmonary edema (APE).Although not always
apparent at presentation, it is important to find the cause of the exacerbation.
This patient, for instance, has been noncompliant with his medications.
Treatment begins by assessing the airway, breathing, and circulation (ABCs).
Initial stabilization is aimed at maintaining airway control and adequate ven-
tilation. Preload and afterload reduction is integral with nitroglycerinbeing
Chest Pain and Cardiac Dysrhythmias Answers 37