20.A 61-year-old woman with a history of diabetes and hypertension is
brought to the ED by her daughter. The patient states that she started feel-
ing short of breath approximately 12 hours ago and then noticed a tingling
sensation in the middle of her chest and became diaphoretic. An ECG
reveals ST-depression in leads II, III, and aVF. You believe that the patient
had a non–ST-elevation MI. Which of the following cardiac markers begins
to rise within 3 to 6 hours of chest pain onset, peaks at 12 to 24 hours, and
returns to baseline in 7 to 10 days?
a. Myoglobin
b. Creatinine kinase (CK)
c. Creatinine kinase-MB (CK-MB)
d. Troponin I
e. Lactic dehydrogenase (LDH)
21.A 27-year-old man complains of chest palpitations and lightheaded-
ness for the past hour. He has no past medical history and is not taking any
medications. He drinks a beer occasionally on the weekend and does not
smoke cigarettes. His HR is 180 beats per minute, BP is 110/65 mm Hg, and
oxygen saturation is 99% on room air. An ECG reveals a HR of 180 beats per
minute with a QRS complex of 90 msec with a regular rhythm. There are no
discernable P waves. Which of the following is the most appropriate med-
ication to treat this dysrhythmia?
a. Digoxin
b. Lidocaine
c. Amiodarone
d. Adenosine
e. Bretylium
12 Emergency Medicine