AAMA AAMA Electrocardiography and Diagnostic Testing 1 — Questions and Answers
Question 1: How many electrodes are placed on a patient for a standard 12-lead ECG?
- 10 electrodes (Correct answer)
- 12 electrodes
- 4 electrodes
- 6 electrodes
Correct answer: 10 electrodes
A 12-lead ECG uses 10 electrodes (4 limb and 6 precordial) to produce 12 different views of the heart's electrical activity.
Question 2: Which ECG wave represents ventricular depolarization?
- QRS complex (Correct answer)
- P wave
- T wave
- U wave
Correct answer: QRS complex
The QRS complex represents the electrical depolarization of the ventricles, which triggers ventricular contraction.
Question 3: What artifact on an ECG is caused by patient movement or shivering?
- Somatic tremor artifact (Correct answer)
- AC interference
- Baseline drift
- Wandering baseline
Correct answer: Somatic tremor artifact
Somatic tremor artifact appears as irregular, erratic baseline variation caused by voluntary or involuntary patient muscle movement.
Question 4: The PR interval on an ECG represents:
- The time for an impulse to travel from the SA node through the AV node (Correct answer)
- Ventricular repolarization
- The time for ventricular depolarization
- Atrial repolarization only
Correct answer: The time for an impulse to travel from the SA node through the AV node
The PR interval measures the time from the start of atrial depolarization (P wave) through the AV node delay to the start of ventricular depolarization.
Question 5: Which precordial lead is placed at the fourth intercostal space, right sternal border?
- V1 (Correct answer)
- V2
- V3
- V4
Correct answer: V1
V1 is positioned at the fourth intercostal space on the right sternal border, and V2 is at the same level on the left sternal border.
Question 6: Normal sinus rhythm on an ECG is characterized by a rate of:
- 60–100 beats per minute (Correct answer)
- 40–60 beats per minute
- 100–150 beats per minute
- Less than 40 beats per minute
Correct answer: 60–100 beats per minute
Normal sinus rhythm is defined as a regular rhythm originating from the SA node with a rate between 60 and 100 beats per minute.
AAMA AAMA Electrocardiography and Diagnostic Testing 1
How many electrodes are placed on a patient for a standard 12-lead ECG?