CVT Electrocardiography (ECG/EKG) Techniques 2 — Questions and Answers
Question 1: Which ECG lead is considered the best for detecting P waves in most patients?
- Lead I
- Lead II (Correct answer)
- Lead aVR
- Lead V1
Correct answer: Lead II
Lead II is typically best for visualizing P waves because it is oriented parallel to the atrial depolarization vector.
Question 2: A patient's ECG shows a delta wave and short PR interval. Which condition does this suggest?
- Brugada syndrome
- Long QT syndrome
- Wolff-Parkinson-White syndrome (Correct answer)
- Left bundle branch block
Correct answer: Wolff-Parkinson-White syndrome
WPW syndrome is characterized by a delta wave (slurred QRS upstroke) and shortened PR interval due to an accessory conduction pathway.
Question 3: What is the standard paper speed used for routine 12-lead ECG recording in the United States?
- 10 mm/sec
- 25 mm/sec (Correct answer)
- 50 mm/sec
- 100 mm/sec
Correct answer: 25 mm/sec
25 mm/sec is the standard paper speed in the US, making each small box represent 0.04 seconds.
Question 4: When recording a 12-lead ECG, electrodes V1 and V2 are placed at which intercostal space?
- 2nd intercostal space
- 3rd intercostal space
- 4th intercostal space (Correct answer)
- 5th intercostal space
Correct answer: 4th intercostal space
V1 is placed at the 4th intercostal space to the right of the sternum, and V2 is placed at the 4th intercostal space to the left of the sternum.
Question 5: Which artifact on an ECG is most commonly caused by patient muscle tremor or shivering?
- Baseline wander
- AC interference
- Somatic tremor artifact (Correct answer)
- Lead reversal artifact
Correct answer: Somatic tremor artifact
Somatic tremor artifact appears as irregular, high-frequency oscillations on the baseline caused by involuntary muscle activity.
Question 6: In a right bundle branch block (RBBB), which lead best demonstrates the characteristic RSR' pattern?
- Lead I
- Lead II
- Lead V1 (Correct answer)
- Lead V6
Correct answer: Lead V1
The classic RSR' (rabbit ears) pattern of RBBB is best seen in lead V1 due to delayed right ventricular activation.
Question 7: How long should a continuous rhythm strip typically be recorded during a standard 12-lead ECG acquisition?
- 2.5 seconds
- 5 seconds
- 10 seconds (Correct answer)
- 30 seconds
Correct answer: 10 seconds
A standard 12-lead ECG records 10 seconds of cardiac rhythm, capturing approximately 10–15 cardiac cycles at a normal heart rate.
CVT Electrocardiography (ECG/EKG) Techniques 2
Which ECG lead is considered the best for detecting P waves in most patients?