Cardiac Vascular Nursing Exam Cardiac Vascular Nursing Exam Diagnostic Testing & Interpretation 2 — Questions and Answers
Question 1: On a rhythm strip, a nurse identifies a pattern where the PR interval progressively lengthens until a P wave fails to conduct (dropped QRS). Which dysrhythmia is this?
- Second-degree AV block, Mobitz Type I (Wenckebach) (Correct answer)
- Second-degree AV block, Mobitz Type II
- Complete (third-degree) heart block
- First-degree AV block
Correct answer: Second-degree AV block, Mobitz Type I (Wenckebach)
Wenckebach block is characterized by progressive PR prolongation due to increasing AV node fatigue until a beat is blocked, then the cycle resets with a shorter PR interval.
Question 2: During a nuclear stress test, which finding indicates a fixed perfusion defect rather than ischemia?
- A perfusion defect present on both stress and rest images that does not change indicates prior infarction (scar) (Correct answer)
- A defect seen on stress imaging that fills in on rest imaging indicates fixed scar tissue
- Uniform tracer uptake in all myocardial segments on both images
- Increased tracer uptake in the right ventricle on stress images only
Correct answer: A perfusion defect present on both stress and rest images that does not change indicates prior infarction (scar)
A fixed defect (unchanged between stress and rest images) represents non-viable scar tissue from prior MI; a reversible defect (defect on stress, normal at rest) represents inducible ischemia.
Question 3: Which ECG finding in a post-cardiac surgery patient warrants immediate physician notification due to risk of cardiac tamponade?
- Electrical alternans (alternating QRS amplitude) with sinus tachycardia and low voltage (Correct answer)
- Isolated ST elevation in lead II only
- New right bundle branch block without hemodynamic changes
- Sinus bradycardia at 58 beats per minute
Correct answer: Electrical alternans (alternating QRS amplitude) with sinus tachycardia and low voltage
Electrical alternans—beat-to-beat variation in QRS amplitude—combined with sinus tachycardia and low voltage is pathognomonic for cardiac tamponade, requiring immediate intervention.
Question 4: A patient's cardiac catheterization report shows 75% stenosis of the left anterior descending (LAD) artery. The nurse understands this supplies which myocardial territory?
- Anterior left ventricular wall, interventricular septum, and apex (Correct answer)
- Inferior wall of the left ventricle and posterior septum
- Lateral wall and posterior left ventricle predominantly
- Right ventricle and right atrium exclusively
Correct answer: Anterior left ventricular wall, interventricular septum, and apex
The LAD perfuses the anterior wall, anterior two-thirds of the interventricular septum, and the cardiac apex, making it critical to a large amount of left ventricular mass.
Question 5: A transesophageal echocardiogram (TEE) is preferred over transthoracic echocardiogram (TTE) for which clinical indication?
- Detection of left atrial appendage thrombus in atrial fibrillation prior to cardioversion (Correct answer)
- Assessment of global left ventricular function in a cooperative patient
- Initial evaluation of aortic stenosis valve gradient
- Bedside monitoring of fluid responsiveness in ICU patients
Correct answer: Detection of left atrial appendage thrombus in atrial fibrillation prior to cardioversion
TEE provides superior visualization of the left atrial appendage because of its posterior acoustic window, making it the standard of care for ruling out LAA thrombus before cardioversion.
Question 6: Which cardiac biomarker pattern is most consistent with an acute MI that occurred approximately 24-48 hours before the laboratory draw?
- Elevated troponin I with near-peak CK-MB that is beginning to decline (Correct answer)
- Normal troponin I with significantly elevated myoglobin only
- Mildly elevated troponin with markedly elevated BNP as the dominant finding
- Troponin I already returned to normal with isolated CK-MB elevation
Correct answer: Elevated troponin I with near-peak CK-MB that is beginning to decline
Troponin I remains elevated for 7–14 days after MI, while CK-MB peaks at 24 hours and returns to normal by 48–72 hours; at 24–48 hours both remain elevated but CK-MB is declining.
Cardiac Vascular Nursing Exam Cardiac Vascular Nursing Exam Diagnostic Testing & Interpretation 2
On a rhythm strip, a nurse identifies a pattern where the PR interval progressively lengthens until a P wave fails to conduct (dropped QRS).
Which dysrhythmia is this?