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# TNCC (TRAUMA NURSING CORE COURSE) –
CARDIAC EMERGENCIES
## COMPREHENSIVE REVIEW & PRACTICE
EXAMINATION**2026–2027 EDITION | 100 QUESTIONS
| DETAILED RATIONALES**GRADED A+ | ENA TNCC
CERTIFICATION PREPARATION**
# SECTION I: CARDIAC ANATOMY & PHYSIOLOGY REVIEW
(Questions 1-10)
**1. Which layer of the heart is most susceptible to injury from blunt
chest trauma and can result in myocardial contusion?**
A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardium
**Correct Answer: B**
**Rationale:** The myocardium (middle muscular layer) is the thickest
layer and is most vulnerable to blunt trauma. Myocardial contusion is a
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bruise of the heart muscle that can cause dysrhythmias, wall motion
abnormalities, and cardiac failure.
---
**2. The right ventricle is the most commonly injured cardiac chamber
in blunt chest trauma because:**
A) It is located posteriorly and protected by the spine
B) It lies directly behind the sternum and is the most anterior chamber
C) It has the thickest myocardial wall
D) It is the smallest chamber
**Correct Answer: B**
**Rationale:** The right ventricle lies directly behind the sternum and
is the most anterior cardiac chamber, making it most vulnerable to blunt
trauma (steering wheel, dashboard). The left ventricle is thicker and
more posterior.
---
**3. The normal pressure in the pericardial space is:**
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A) 0–5 mmHg (slightly negative to atmospheric)
B) 15–20 mmHg
C) 30–40 mmHg
D) 60–80 mmHg
**Correct Answer: A**
**Rationale:** Pericardial pressure is normally 0–5 mmHg (slightly
negative). As little as 150–200 mL of blood in the pericardial sac (acute)
can cause cardiac tamponade with pressures >15–20 mmHg.
---
**4. Cardiac output (CO) is calculated as:**
A) Stroke volume (SV) × Heart rate (HR)
B) Systolic BP + Diastolic BP / 3
C) Central venous pressure (CVP) × HR
D) End-diastolic volume – End-systolic volume
**Correct Answer: A**
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**Rationale:** Cardiac output = Stroke volume × Heart rate. Normal
CO is 4–8 L/min. Stroke volume is affected by preload, contractility, and
afterload.
---
**5. Which coronary artery is most commonly injured in penetrating
cardiac trauma?**
A) Left anterior descending (LAD)
B) Right coronary artery (RCA)
C) Circumflex artery
D) Posterior descending artery
**Correct Answer: A**
**Rationale:** The LAD is the most anterior coronary artery and is
most vulnerable to penetrating injuries (stab wounds, gunshot wounds).
Injury to the LAD typically causes massive anterior wall infarction and
carries high mortality.
---
# TNCC (TRAUMA NURSING CORE COURSE) –
CARDIAC EMERGENCIES
## COMPREHENSIVE REVIEW & PRACTICE
EXAMINATION**2026–2027 EDITION | 100 QUESTIONS
| DETAILED RATIONALES**GRADED A+ | ENA TNCC
CERTIFICATION PREPARATION**
# SECTION I: CARDIAC ANATOMY & PHYSIOLOGY REVIEW
(Questions 1-10)
**1. Which layer of the heart is most susceptible to injury from blunt
chest trauma and can result in myocardial contusion?**
A) Epicardium
B) Myocardium
C) Endocardium
D) Pericardium
**Correct Answer: B**
**Rationale:** The myocardium (middle muscular layer) is the thickest
layer and is most vulnerable to blunt trauma. Myocardial contusion is a
,2|Page
bruise of the heart muscle that can cause dysrhythmias, wall motion
abnormalities, and cardiac failure.
---
**2. The right ventricle is the most commonly injured cardiac chamber
in blunt chest trauma because:**
A) It is located posteriorly and protected by the spine
B) It lies directly behind the sternum and is the most anterior chamber
C) It has the thickest myocardial wall
D) It is the smallest chamber
**Correct Answer: B**
**Rationale:** The right ventricle lies directly behind the sternum and
is the most anterior cardiac chamber, making it most vulnerable to blunt
trauma (steering wheel, dashboard). The left ventricle is thicker and
more posterior.
---
**3. The normal pressure in the pericardial space is:**
,3|Page
A) 0–5 mmHg (slightly negative to atmospheric)
B) 15–20 mmHg
C) 30–40 mmHg
D) 60–80 mmHg
**Correct Answer: A**
**Rationale:** Pericardial pressure is normally 0–5 mmHg (slightly
negative). As little as 150–200 mL of blood in the pericardial sac (acute)
can cause cardiac tamponade with pressures >15–20 mmHg.
---
**4. Cardiac output (CO) is calculated as:**
A) Stroke volume (SV) × Heart rate (HR)
B) Systolic BP + Diastolic BP / 3
C) Central venous pressure (CVP) × HR
D) End-diastolic volume – End-systolic volume
**Correct Answer: A**
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**Rationale:** Cardiac output = Stroke volume × Heart rate. Normal
CO is 4–8 L/min. Stroke volume is affected by preload, contractility, and
afterload.
---
**5. Which coronary artery is most commonly injured in penetrating
cardiac trauma?**
A) Left anterior descending (LAD)
B) Right coronary artery (RCA)
C) Circumflex artery
D) Posterior descending artery
**Correct Answer: A**
**Rationale:** The LAD is the most anterior coronary artery and is
most vulnerable to penetrating injuries (stab wounds, gunshot wounds).
Injury to the LAD typically causes massive anterior wall infarction and
carries high mortality.
---
