ADVENT HEALTH EKG
COMPREHENSIVE QUESTIONS AND
ANSWERS
1. What is the standard duration for a normal PR interval?
A. 0.04 to 0.10 seconds
B. 0.20 to 0.24 seconds
C. 0.12 to 0.20 seconds
D. 0.36 to 0.44 seconds
Answer: C
Conceptual Explanation: A normal PR interval reflects the time taken for the impulse to
travel from the SA node to the ventricles and is measured from the start of the P wave to
the start of the QRS complex, typically 0.12-0.20 seconds.
2. Which lead is placed at the fourth intercostal space, right sternal border?
A. Lead II
B. V2
C. V4
,D. V1
Answer: D
Conceptual Explanation: V1 is the first precordial lead and is placed at the 4th intercostal
space at the right margin of the sternum.
3. Tall, peaked T-waves are most frequently associated with which electrolyte imbalance?
A. Hypocalcemia
B. Hyperkalemia
C. Hypermagnesemia
D. Hyponatremia
Answer: B
Conceptual Explanation: Hyperkalemia (high potassium) causes rapid repolarization of
the ventricles, resulting in narrow, peaked T-waves.
4. A rhythm characterized by a ‘sawtooth’ baseline and an atrial rate between 250-350 bpm
is:
A. Atrial Flutter
B. Ventricular Tachycardia
C. Atrial Fibrillation
D. Sinus Tachycardia
, Answer: A
Conceptual Explanation: Atrial flutter is characterized by rapid, regular atrial
depolarizations that appear as sawtooth ‘F’ waves.
5. Which heart block is characterized by a progressive lengthening of the PR interval until a
QRS complex is dropped?
A. First-degree AV block
B. Third-degree AV block
C. Second-degree AV block, Mobitz Type II
D. Second-degree AV block, Mobitz Type I (Wenckebach)
Answer: D
Conceptual Explanation: Mobitz Type I (Wenckebach) involves a cyclical lengthening of
the PR interval until an atrial impulse is blocked at the AV node.
6. A wide QRS complex (greater than 0.12 seconds) is typically indicative of:
A. Delay in ventricular depolarization
B. Supraventricular origin of the rhythm
C. Rapid SA node firing
D. Normal conduction through the Bundle of His
Answer: A
COMPREHENSIVE QUESTIONS AND
ANSWERS
1. What is the standard duration for a normal PR interval?
A. 0.04 to 0.10 seconds
B. 0.20 to 0.24 seconds
C. 0.12 to 0.20 seconds
D. 0.36 to 0.44 seconds
Answer: C
Conceptual Explanation: A normal PR interval reflects the time taken for the impulse to
travel from the SA node to the ventricles and is measured from the start of the P wave to
the start of the QRS complex, typically 0.12-0.20 seconds.
2. Which lead is placed at the fourth intercostal space, right sternal border?
A. Lead II
B. V2
C. V4
,D. V1
Answer: D
Conceptual Explanation: V1 is the first precordial lead and is placed at the 4th intercostal
space at the right margin of the sternum.
3. Tall, peaked T-waves are most frequently associated with which electrolyte imbalance?
A. Hypocalcemia
B. Hyperkalemia
C. Hypermagnesemia
D. Hyponatremia
Answer: B
Conceptual Explanation: Hyperkalemia (high potassium) causes rapid repolarization of
the ventricles, resulting in narrow, peaked T-waves.
4. A rhythm characterized by a ‘sawtooth’ baseline and an atrial rate between 250-350 bpm
is:
A. Atrial Flutter
B. Ventricular Tachycardia
C. Atrial Fibrillation
D. Sinus Tachycardia
, Answer: A
Conceptual Explanation: Atrial flutter is characterized by rapid, regular atrial
depolarizations that appear as sawtooth ‘F’ waves.
5. Which heart block is characterized by a progressive lengthening of the PR interval until a
QRS complex is dropped?
A. First-degree AV block
B. Third-degree AV block
C. Second-degree AV block, Mobitz Type II
D. Second-degree AV block, Mobitz Type I (Wenckebach)
Answer: D
Conceptual Explanation: Mobitz Type I (Wenckebach) involves a cyclical lengthening of
the PR interval until an atrial impulse is blocked at the AV node.
6. A wide QRS complex (greater than 0.12 seconds) is typically indicative of:
A. Delay in ventricular depolarization
B. Supraventricular origin of the rhythm
C. Rapid SA node firing
D. Normal conduction through the Bundle of His
Answer: A
