CPEN Cardiac Emergencies 5 — Questions and Answers
Question 1: A 14-year-old presents with chest pain, fever, and a friction rub. ECG shows diffuse ST elevation with PR depression in most leads. The most likely diagnosis is:
- Acute MI from coronary vasospasm
- Pericarditis (Correct answer)
- Pulmonary embolism
- Hypertrophic cardiomyopathy
Correct answer: Pericarditis
Diffuse saddle-shaped ST elevation with PR depression in most leads, plus a friction rub, is the classic presentation of pericarditis.
Question 2: Beck's triad (hypotension, muffled heart sounds, distended neck veins) in a trauma patient suggests:
- Tension pneumothorax
- Cardiac tamponade (Correct answer)
- Aortic dissection
- Massive hemothorax
Correct answer: Cardiac tamponade
Beck's triad is the hallmark of cardiac tamponade, caused by fluid accumulation in the pericardial sac compressing the heart.
Question 3: The emergency bedside procedure to relieve cardiac tamponade is:
- Needle thoracostomy
- Pericardiocentesis (Correct answer)
- Chest tube insertion
- Emergent thoracotomy
Correct answer: Pericardiocentesis
Pericardiocentesis (needle aspiration of pericardial fluid) rapidly relieves tamponade by decompressing the pericardial space.
Question 4: Which blood pressure finding is classic for cardiac tamponade?
- Hypertension with wide pulse pressure
- Pulsus paradoxus >10 mmHg (Correct answer)
- Orthostatic hypotension only
- Fixed narrow pulse pressure unaffected by respiration
Correct answer: Pulsus paradoxus >10 mmHg
Pulsus paradoxus (>10 mmHg drop in systolic BP with inspiration) occurs in tamponade due to exaggerated ventricular interdependence from pericardial pressure.
Question 5: A 9-year-old with known dilated cardiomyopathy presents with new-onset pulmonary edema. Which finding would indicate cardiogenic shock rather than isolated pulmonary edema?
- SpO2 of 90% on room air
- Heart rate of 130 bpm
- Altered mental status with cool mottled extremities (Correct answer)
- Bilateral crackles on auscultation
Correct answer: Altered mental status with cool mottled extremities
Altered mental status with poor perfusion signs (cool, mottled extremities) indicates end-organ hypoperfusion, the defining feature of cardiogenic shock.
Question 6: A child post-cardiac surgery develops sudden hypotension, tachycardia, and JVD with equalization of right and left heart filling pressures. The nurse should suspect:
- Mediastinitis
- Postoperative cardiac tamponade (Correct answer)
- Pulmonary hypertensive crisis
- Chylothorax
Correct answer: Postoperative cardiac tamponade
Equalization of diastolic pressures across cardiac chambers combined with hypotension post-cardiac surgery indicates postoperative tamponade from pericardial hemorrhage.
Question 7: Commotio cordis most commonly results from a blow to the chest during which cardiac cycle phase?
- P wave (atrial depolarization)
- QRS complex (ventricular depolarization)
- T wave upstroke (vulnerable period of repolarization) (Correct answer)
- PR interval (AV node conduction)
Correct answer: T wave upstroke (vulnerable period of repolarization)
Commotio cordis occurs when a blunt chest impact strikes during the vulnerable period of ventricular repolarization (T wave upstroke), triggering VF.
CPEN Cardiac Emergencies 5
A 14-year-old presents with chest pain, fever, and a friction rub.
ECG shows diffuse ST elevation with PR depression in most leads.
The most likely diagnosis is: