ECG Interpretation Quizzes: Master Electrocardiogram Analysis

Question 1

Which of the following is the normal sequence of ECG components?

Accepted Answer

P wave - QRS complex - T wave

Answer

QRS complex - T wave - P wave

Answer

P wave - T wave - QRS complex

Answer

T wave - QRS complex - P wave

Question 2

Atrial fibrillation is characterized by:

Accepted Answer

Irregular P waves and irregular QRS complexes

Answer

Regular P waves and QRS complexes

Answer

Irregular P waves and regular QRS complexes

Answer

Regular P waves and irregular QRS complexes

Question 3

Which of the following is commonly seen in a bradycardic rhythm?

Accepted Answer

Long PR interval

Answer

Short PR interval

Answer

Wide QRS complex

Answer

Delta waves

Question 4

The presence of a delta wave in an ECG is typically associated with:

Accepted Answer

Wolff-Parkinson-White syndrome

Answer

Long QT syndrome

Answer

Atrial fibrillation

Answer

Sinus tachycardia

Question 5

A prolonged QT interval is associated with:

Accepted Answer

Increased risk of ventricular arrhythmias

Answer

Decreased risk of ventricular arrhythmias

Answer

Normal sinus rhythm

Answer

Increased heart rate

Question 6

In a standard 12-lead ECG, the lead that is placed on the right leg is:

Accepted Answer

Lead aVR

Answer

Lead I

Answer

Lead II

Answer

Lead III

Question 7

On an electrocardiogram (ECG), an elongated PR segment (≥0.20 seconds) is most commonly associated with:

Accepted Answer

First-degree AV block

Answer

Normal atrioventricular (AV) conduction

Answer

Second-degree AV block

Answer

Third-degree AV block

Question 8

A patient with a heart rate of 150 beats per minute (bpm) and a regular rhythm is most likely experiencing:

Accepted Answer

Sinus tachycardia

Answer

Atrial fibrillation

Answer

Ventricular tachycardia

Answer

Supraventricular tachycardia

Question 9

Which ECG change is indicative of left ventricular hypertrophy?

Accepted Answer

Tall R waves in leads V5 and V6

Answer

Deep S waves in leads V1 and V2

Answer

Inverted T waves in leads III and aVF

Answer

ST segment depression in leads II, III, and aVF

Question 10

What is the clinical significance of a QTc interval greater than 500 milliseconds?

Accepted Answer

Increased risk of torsades de pointes

Answer

Normal finding in elderly patients

Answer

Associated with bradycardia

Answer

Requires no further evaluation

Question 11

Which ECG lead placement provides the clearest view of the heart's inferior wall?

Accepted Answer

Lead aVF

Answer

Lead II

Answer

Lead III

Answer

Lead V6

Question 12

The most common cause of ST segment elevation on an ECG is:

Accepted Answer

Acute myocardial infarction

Answer

Pericarditis

Answer

Pulmonary embolism

Answer

Hyperkalemia

Question 13

Which ECG criteria is used to diagnose Wolff-Parkinson-White (WPW) syndrome?

Accepted Answer

Shortened PR interval and delta waves

Answer

Prolonged PR interval and peaked T waves

Answer

Wide QRS complex and RBBB pattern

Answer

Inverted P waves and biphasic T waves

Question 14

Which ECG finding suggests left atrial enlargement?

Accepted Answer

Inverted T waves in leads II, III, and aVF

Answer

Prolonged PR interval

Answer

Narrow QRS complex

Answer

Elevated ST segment in leads V1-V3

Question 15

What is the most common cause of ST-segment elevation on an ECG?

Accepted Answer

Acute myocardial infarction

Answer

Pericarditis

Answer

Electrolyte imbalances

Answer

Drug overdose

Question 16

Which ECG feature is characteristic of ventricular fibrillation?

Accepted Answer

Irregular and chaotic QRS complexes

Answer

Narrow QRS complexes

Answer

Slow heart rate

Answer

Regular P waves

Question 17

When performing an ECG, which electrode placement is used for lead II?

Accepted Answer

Left arm to right leg

Answer

Right arm to left leg

Answer

Left leg to right arm

Answer

Chest to back

Question 18

Which ECG interval represents the duration from the start of ventricular depolarization to the end of ventricular repolarization?

Accepted Answer

QT interval

Answer

PR interval

Answer

ST segment

Answer

P wave

Question 19

A heart rate of 100 beats per minute with regular P waves preceding each QRS complex is most likely indicative of:

Accepted Answer

Sinus tachycardia

Answer

Atrial fibrillation

Answer

Ventricular tachycardia

Answer

Heart block

Question 20

Which ECG finding is strongly suggestive of an acute myocardial infarction?

Accepted Answer

ST segment elevation

Answer

Bundle branch block

Answer

Inverted T wave

Answer

Prolonged PR interval

Question 21

A QRS complex exceeding 0.12 seconds in duration is considered:

Accepted Answer

Wide

Answer

Normal

Answer

Narrow

Answer

Blocked

Question 22

Which type of heart block occurs when the electrical signal fails to conduct from the atria to the ventricles?

Accepted Answer

Atrioventricular block

Answer

Sinoatrial block

Answer

Intraventricular block

Answer

Bundle branch block

Question 23

A small, upright deflection immediately preceding the QRS complex is known as the:

Accepted Answer

P wave

Answer

R' wave

Answer

U wave

Answer

T wave

Question 24

Which QRS axis deviation suggests right ventricular hypertrophy?

Accepted Answer

+90 to +180 degrees

Answer

0 to +90 degrees

Answer

-180 to -30 degrees

Answer

-30 to -90 degrees

Question 25

The T wave is normally:

Accepted Answer

Upright in leads I and aVF

Answer

Positive in all leads

Answer

Inverted in leads II and III

Question 26

A U wave is:

Accepted Answer

A small, positive deflection following the T wave

Answer

A negative deflection preceding the P wave

Answer

An artifact caused by electrode placement

Answer

A large, upright deflection following the QRS complex