practice test questions

Question 1

Review Questions
Which lead is considered the ground lead in a 12-lead EKG?
a) Lead I
b) Lead III
c) Right leg
d) Left leg

A QRS complex duration greater than 0.12 seconds is indicative of:
a) Normal conduction
b) Left bundle branch block
c) Right bundle branch block
d) Premature ventricular contraction

Which arrhythmia is characterized by an irregularly irregular rhythm and absence of P waves?
a) Atrial fibrillation
b) Ventricular tachycardia
c) Sinus bradycardia
d) Atrial flutter

A wide QRS complex with a rate of 160 bpm and no visible P waves suggests:
a) Atrial flutter
b) Ventricular tachycardia
c) Sinus tachycardia
d) Normal sinus rhythm

What is the correct order of electrical conduction through the heart?
a) AV node → SA node → Purkinje fibers → Bundle of His
b) SA node → AV node → Bundle of His → Purkinje fibers
c) Bundle of His → SA node → Purkinje fibers → AV node
d) Purkinje fibers → AV node → Bundle of His → SA node

New Questions
What does the ST segment represent on an EKG?
a) Atrial depolarization
b) Ventricular repolarization
c) The time between ventricular depolarization and repolarization
d) Atrial contraction

Which of the following is a potential cause of sinus tachycardia?
a) Hypoxia
b) Hyperkalemia
c) Beta-blocker medication
d) Vagal stimulation

What is the standard speed of an EKG paper?
a) 10 mm/sec
b) 25 mm/sec
c) 50 mm/sec
d) 100 mm/sec

Which part of the heart’s electrical conduction system acts as the primary pacemaker?
a) AV node
b) SA node
c) Purkinje fibers
d) Bundle of His

Which patient condition would likely require a right-sided 12-lead EKG?
a) Left bundle branch block
b) Myocardial infarction affecting the right ventricle
c) Sinus tachycardia
d) Atrial fibrillation

Drop your answers, and I’ll let you know if they’re correct! 😊

You said:
1. b
ChatGPT said:
Incorrect ❌

The correct answer is:
c) Right leg

Explanation:
In a 12-lead EKG, the right leg (RL) electrode serves as the ground lead to help stabilize electrical signals and reduce interference.
Lead I, Lead III, and the left leg electrode are used to measure electrical activity but do not function as the ground lead.