ECG (Electrocardiogram): A graphic representation of the electrical activity of the heart over time, recorded by placing electrodes on the skin.
Take up Quiz on ECG with the questions preparing for competitive examination
1. What does the P wave represent in an ECG?
a) Atrial depolarization
b) Ventricular depolarization
c) Atrial repolarization
d) Ventricular repolarization
Answer: a) Atrial depolarization
2. Which lead is commonly used to monitor the heart’s electrical activity in a standard 12-lead ECG?
a) Lead I
b) Lead II
c) Lead III
d) Lead aVR
Answer: b) Lead II
3. What is the normal duration of the PR interval in an ECG?
a) 0.06-0.10 seconds
b) 0.10-0.20 seconds
c) 0.20-0.40 seconds
d) 0.40-0.60 seconds
Answer: a) 0.06-0.10 seconds
4. Which ECG lead is considered the “inferior” lead?
a) Lead I
b) Lead II
c) Lead III
d) Lead aVF
Answer: d) Lead aVF
5. The QRS complex represents:
a) Atrial depolarization
b) Ventricular depolarization
c) Atrial repolarization
d) Ventricular repolarization
Answer: b) Ventricular depolarization
6. In which precordial lead is the ST segment typically measured to assess for myocardial infarction?
a) V1
b) V2
c) V3
d) V4
Answer: c) V3
7. A prolonged QT interval on an ECG is associated with an increased risk of:
a) Atrial fibrillation
b) Ventricular tachycardia
c) Torsades de pointes
d) Atrial flutter
Answer: c) Torsades de pointes
8. The term “ST-segment elevation” is most commonly associated with:
a) Myocardial infarction
b) Atrial fibrillation
c) Heart block
d) Ventricular tachycardia
Answer: a) Myocardial infarction
9. Which of the following conditions is characterized by a sawtooth pattern on the ECG?
a) Atrial fibrillation
b) Atrial flutter
c) Ventricular tachycardia
d) Supraventricular tachycardia
Answer: b) Atrial flutter
10. The T wave on an ECG represents:
a) Atrial depolarization
b) Ventricular depolarization
c) Atrial repolarization
d) Ventricular repolarization
Answer: d) Ventricular repolarization
ECG (Electrocardiography) MCQs with answers
KEY DEFINITIONS RELATED TO ECG
P Wave: Represents atrial depolarization, or the electrical activity associated with the contraction of the atria.
QRS Complex: Represents ventricular depolarization, or the electrical activity associated with the contraction of the ventricles.
T Wave: Represents ventricular repolarization, or the recovery of the ventricles following contraction.
PR Interval: The time interval from the beginning of the P wave to the beginning of the QRS complex, representing the time it takes for the electrical impulse to travel from the atria to the ventricles.
QT Interval: The time interval from the beginning of the QRS complex to the end of the T wave, representing the total time for ventricular depolarization and repolarization.
ST Segment: The segment of the ECG that represents the period between ventricular depolarization and repolarization, crucial for detecting myocardial ischemia or injury.
Lead: A specific combination of electrodes used to measure electrical activity from a particular angle, providing different perspectives on the heart’s electrical activity.
Atrial Fibrillation: An irregular and often rapid heart rate characterized by chaotic and rapid atrial electrical activity.
Bundle Branch Block: A delay or block in the conduction of electrical impulses through the bundle branches of the heart’s conduction system.
Wolff-Parkinson-White Syndrome: A condition where an additional pathway, called an accessory pathway, exists in the heart, leading to abnormal electrical conduction.
Atrioventricular (AV) Block: Impaired conduction between the atria and ventricles, resulting in a delay or blockage of electrical signals.
Axis Deviation: Deviation from the normal direction of the heart’s electrical axis, providing information about the heart’s position within the chest.
Ischemia: Inadequate blood supply to a part of the heart, often manifested by ST-segment depression on the ECG.
Myocardial Infarction (MI): Death of heart muscle tissue due to insufficient blood supply, commonly indicated by ST-segment elevation on the ECG.
U Wave: A small deflection sometimes seen after the T wave, representing the final phase of ventricular repolarization.
