BCEN Cardiac Emergencies 2 — Questions and Answers
Question 1: A patient presents with chest pain, diaphoresis, and an ECG showing ST elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?
- Left anterior descending artery
- Right coronary artery (Correct answer)
- Left circumflex artery
- Left main coronary artery
Correct answer: Right coronary artery
ST elevation in leads II, III, and aVF indicates an inferior STEMI, most commonly caused by occlusion of the right coronary artery.
Question 2: A patient in ventricular fibrillation receives a defibrillation shock. Which action should the nurse take immediately after shock delivery?
- Check the pulse for 10 seconds
- Resume CPR immediately starting with chest compressions (Correct answer)
- Administer amiodarone 300 mg IV
- Obtain a 12-lead ECG
Correct answer: Resume CPR immediately starting with chest compressions
After defibrillation, CPR should be resumed immediately without a pulse check, as per current AHA guidelines, starting with chest compressions.
Question 3: Which of the following best describes the mechanism of action of adenosine when used to treat SVT?
- Blocks sodium channels to slow conduction
- Temporarily blocks AV nodal conduction to interrupt reentry circuits (Correct answer)
- Increases vagal tone by stimulating the carotid sinus
- Prolongs the refractory period of ventricular myocytes
Correct answer: Temporarily blocks AV nodal conduction to interrupt reentry circuits
Adenosine transiently blocks AV nodal conduction, interrupting the reentry circuit responsible for most SVTs.
Question 4: A patient with acute heart failure has a BP of 88/60 mmHg and bilateral crackles. Which medication is most appropriate to initiate?
- Nitroglycerin IV infusion
- Furosemide 80 mg IV push
- Dobutamine IV infusion (Correct answer)
- Metoprolol tartrate 5 mg IV
Correct answer: Dobutamine IV infusion
In cardiogenic shock with hypotension, dobutamine is the preferred agent as it provides inotropic support without further reducing blood pressure.
Question 5: A patient is admitted with a serum potassium of 6.8 mEq/L and peaked T waves on ECG. Which intervention should be performed FIRST?
- Administer sodium polystyrene sulfonate (Kayexalate)
- Administer calcium gluconate IV (Correct answer)
- Initiate hemodialysis
- Administer sodium bicarbonate IV
Correct answer: Administer calcium gluconate IV
Calcium gluconate is given first to stabilize the cardiac membrane and protect against life-threatening arrhythmias from hyperkalemia.
Question 6: During transcutaneous pacing, the nurse notes electrical capture but the patient remains unresponsive. What is the most likely explanation?
- The pacemaker output is set too low
- Mechanical capture has not been achieved (Correct answer)
- The pacing rate is too slow
- Lead placement is incorrect
Correct answer: Mechanical capture has not been achieved
Electrical capture (pacing spikes followed by wide QRS) does not guarantee mechanical capture; mechanical capture must be confirmed by a palpable pulse or improved blood pressure.
Question 7: A patient with known coronary artery disease develops new left bundle branch block (LBBB) with chest pain. How should this be managed?
- Observe and repeat ECG in 6 hours
- Treat as a STEMI equivalent and activate the cath lab (Correct answer)
- Administer aspirin only and admit for monitoring
- Perform immediate synchronized cardioversion
Correct answer: Treat as a STEMI equivalent and activate the cath lab
New LBBB in the setting of chest pain is treated as a STEMI equivalent per AHA/ACC guidelines, requiring urgent reperfusion therapy.
BCEN Cardiac Emergencies 2
A patient presents with chest pain, diaphoresis, and an ECG showing ST elevation in leads II, III, and aVF.
Which coronary artery is most likely occluded?