Master the board step 3

Cardiology
Beta Blockers, ACE Inhibitors, and Angiotensin Receptor Blockers
Beta blockers lower mortality, but the timing of their administration is not
critical. Beta blockers, such as metoprolol, should be given, but they are not as
urgent to give as aspirin, thrombolytics, or primary angioplasty. ACE inhibitors
or angiotensin receptor blockers (ARBs) should be given to all patients
with an acute coronary syndrome, but they only lower mortality if there is left
ventricular dysfunction or systolic dysfunction. Make sure there is a lipid
profile and start the patient on HMG CoA reductase inhibitors, if indicated
(i.e., if LDL is not at goal).
Basic Science Correlate
Mechanism of Beta Blockers in Myocardial Infarction
The most common cause of death in both CHF and MI is a ventricular
arrhythmia brought on by ischemia. Beta blockers are both anti-arrhythmic
and anti-ischemic. Slower heart rate means more time for coronary artery
perfusion. Increased left ventricular filling time increases both stroke volume
and cardiac output.
CCS Tip: CCS and Step 3 do not require you to know doses.
A 72-year-old man comes to the emergency department having had chest pain for
the last hour. His initial EKG shows ST segment elevation in leads V2–V4. Aspirin
has been given. Which of the following will most likely benefit this patient?
a. CK-MB
b. Stress test
c. Angioplasty
d. Metoprolol
e. Diltiazem
f. Atorvastatin
g. Digoxin
h. Amiodarone
i. Oxygen, morphine, and nitrates
j. Thrombolytics
Answer: C. Angioplasty will lower the risk of mortality most for this patient. If it can
be obtained within 90 minutes, angioplasty is the best therapy. Metoprolol lowers
mortality but is not dependent on how soon you give it, as long as the patient receives
it before going home.
Statins
Statin medications, such as atorvastatin, should be given to all patients with
an acute coronary syndrome, regardless of what the EKG shows or troponin
or CK-MB levels.
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