ELIAS ADVANCED DYSRHYTHMIA
EXAM REVIEW QUESTIONS AND
ANSWERS
1. In a third-degree AV block, what is the primary relationship between the P waves and the
QRS complexes?
A. The PR interval progressively lengthens until a QRS is dropped.
B. Every other P wave is followed by a QRS complex.
C. The PR interval is constant but greater than 0.20 seconds.
D. There is no relationship between P waves and QRS complexes.
Answer: D
Conceptual Explanation: In third-degree (complete) heart block, the atria and ventricles
beat independently because the impulse from the atria is completely blocked at the AV
node or bundle branches, resulting in AV dissociation.
2. Which of the following is the hallmark ECG finding of Wolff-Parkinson-White (WPW)
syndrome?
A. A prolonged PR interval and narrowed QRS.
,B. Inverted T waves in the precordial leads.
C. A saw-tooth pattern in leads II, III, and aVF.
D. A short PR interval and a delta wave on the QRS complex.
Answer: D
Conceptual Explanation: WPW syndrome is characterized by an accessory pathway
(Bundle of Kent) that bypasses the AV node, leading to early ventricular depolarization
seen as a short PR interval and a slurred upstroke of the QRS, known as a delta wave.
3. What is the drug of choice for the treatment of Torsades de Pointes?
A. Magnesium Sulfate
B. Amiodarone
C. Epinephrine
D. Adenosine
Answer: A
Conceptual Explanation: Magnesium Sulfate is the first-line treatment for Torsades de
Pointes, a specific form of polymorphic ventricular tachycardia associated with a prolonged
QT interval.
4. A patient has a rhythm with a rate of 45 bpm, no P waves, and a QRS width of 0.14
seconds. What is the most likely rhythm?
A. Junctional Escape Rhythm
, B. Idioventricular Rhythm
C. Sinus Bradycardia
D. Second-degree Heart Block Type II
Answer: B
Conceptual Explanation: An idioventricular rhythm typically has a rate of 20-40 bpm (or
slightly higher if accelerated), no P waves, and a wide QRS complex (>0.12s) as the impulse
originates in the ventricles.
5. Which electrolyte abnormality is most likely to cause the appearance of U waves and a
flattened T wave?
A. Hyperkalemia
B. Hypocalcemia
C. Hypermagnesemia
D. Hypokalemia
Answer: D
Conceptual Explanation: Hypokalemia often presents with prominent U waves, flattened
or inverted T waves, and ST-segment depression.
6. How is a Mobitz Type II second-degree AV block distinguished from a Mobitz Type I
(Wenckebach)?
A. Mobitz I never has a regular P-P interval.
EXAM REVIEW QUESTIONS AND
ANSWERS
1. In a third-degree AV block, what is the primary relationship between the P waves and the
QRS complexes?
A. The PR interval progressively lengthens until a QRS is dropped.
B. Every other P wave is followed by a QRS complex.
C. The PR interval is constant but greater than 0.20 seconds.
D. There is no relationship between P waves and QRS complexes.
Answer: D
Conceptual Explanation: In third-degree (complete) heart block, the atria and ventricles
beat independently because the impulse from the atria is completely blocked at the AV
node or bundle branches, resulting in AV dissociation.
2. Which of the following is the hallmark ECG finding of Wolff-Parkinson-White (WPW)
syndrome?
A. A prolonged PR interval and narrowed QRS.
,B. Inverted T waves in the precordial leads.
C. A saw-tooth pattern in leads II, III, and aVF.
D. A short PR interval and a delta wave on the QRS complex.
Answer: D
Conceptual Explanation: WPW syndrome is characterized by an accessory pathway
(Bundle of Kent) that bypasses the AV node, leading to early ventricular depolarization
seen as a short PR interval and a slurred upstroke of the QRS, known as a delta wave.
3. What is the drug of choice for the treatment of Torsades de Pointes?
A. Magnesium Sulfate
B. Amiodarone
C. Epinephrine
D. Adenosine
Answer: A
Conceptual Explanation: Magnesium Sulfate is the first-line treatment for Torsades de
Pointes, a specific form of polymorphic ventricular tachycardia associated with a prolonged
QT interval.
4. A patient has a rhythm with a rate of 45 bpm, no P waves, and a QRS width of 0.14
seconds. What is the most likely rhythm?
A. Junctional Escape Rhythm
, B. Idioventricular Rhythm
C. Sinus Bradycardia
D. Second-degree Heart Block Type II
Answer: B
Conceptual Explanation: An idioventricular rhythm typically has a rate of 20-40 bpm (or
slightly higher if accelerated), no P waves, and a wide QRS complex (>0.12s) as the impulse
originates in the ventricles.
5. Which electrolyte abnormality is most likely to cause the appearance of U waves and a
flattened T wave?
A. Hyperkalemia
B. Hypocalcemia
C. Hypermagnesemia
D. Hypokalemia
Answer: D
Conceptual Explanation: Hypokalemia often presents with prominent U waves, flattened
or inverted T waves, and ST-segment depression.
6. How is a Mobitz Type II second-degree AV block distinguished from a Mobitz Type I
(Wenckebach)?
A. Mobitz I never has a regular P-P interval.
