ECG Online Electrocardiogram 2 — Questions and Answers
Question 1: How many electrodes are placed on the body to record a standard 12-lead ECG?
- 6
- 10 (Correct answer)
- 12
- 15
Correct answer: 10
Ten electrodes (four limb and six chest) produce the 12 leads of a standard ECG.
Question 2: Which chest lead is placed at the fourth intercostal space to the right of the sternum?
- V1 (Correct answer)
- V2
- V4
- V6
Correct answer: V1
V1 sits at the fourth intercostal space just right of the sternum.
Question 3: What does the P wave on an ECG represent?
- Ventricular depolarization
- Atrial depolarization (Correct answer)
- Ventricular repolarization
- Bundle branch conduction
Correct answer: Atrial depolarization
The P wave reflects depolarization (contraction) of the atria.
Question 4: The standard paper speed for recording an ECG is:
- 10 mm/sec
- 25 mm/sec (Correct answer)
- 50 mm/sec
- 100 mm/sec
Correct answer: 25 mm/sec
ECG paper runs at a standard speed of 25 mm/sec.
Question 5: Which limb electrode is typically used as the ground (reference) electrode?
- Right arm
- Left arm
- Right leg (Correct answer)
- Left leg
Correct answer: Right leg
The right leg electrode serves as the ground reference.
Question 6: A normal adult resting heart rate falls within which range?
- 30-50 bpm
- 60-100 bpm (Correct answer)
- 100-140 bpm
- 140-180 bpm
Correct answer: 60-100 bpm
A normal adult resting heart rate is 60 to 100 beats per minute.
Question 7: Wandering baseline artifact on an ECG tracing is most often caused by:
- Patient movement or respiration (Correct answer)
- Correct electrode placement
- High paper speed
- A fully charged machine
Correct answer: Patient movement or respiration
Baseline wander commonly results from patient movement, breathing, or loose electrodes.
ECG Online Electrocardiogram 2
How many electrodes are placed on the body to record a standard 12-lead ECG?