#1
Which component of the ECG represents the time taken for electrical impulses to travel from the atria to the ventricles?
P wave
QRS complex
PR interval
T wave
#2
What does the QRS complex represent in an ECG?
Atrial depolarization
Ventricular repolarization
Ventricular depolarization
Atrial repolarization
#3
What is the normal duration of the PR interval on an ECG?
0.04 to 0.10 seconds
0.10 to 0.20 seconds
0.12 to 0.20 seconds
0.20 to 0.40 seconds
#4
What is the expected heart rate in sinus bradycardia?
Less than 60 beats per minute
60 to 100 beats per minute
100 to 150 beats per minute
Greater than 150 beats per minute
#5
Which dysrhythmia is characterized by chaotic, irregular electrical activity in the atria?
Atrial fibrillation
Ventricular fibrillation
Atrial flutter
Ventricular tachycardia
#6
What does a prolonged QT interval on an ECG indicate?
Ventricular repolarization
Ventricular depolarization
Atrial repolarization
Atrial depolarization
#7
Which ECG lead placement is commonly used to detect myocardial infarction involving the inferior wall of the heart?
Lead I
Lead II
Lead III
Lead V1
#8
Which medication is commonly used to terminate supraventricular tachycardia by slowing conduction through the AV node?
Amiodarone
Adenosine
Lidocaine
Procainamide
#9
Which ECG finding is characteristic of hyperkalemia?
Prolonged PR interval and peaked T waves
Shortened QT interval and flattened T waves
Prolonged QT interval and widened QRS complex
Absent P waves and irregularly irregular rhythm
#10
What is the term for an ectopic focus in the atria that fires rapidly and repetitively, resulting in atrial rates of 250 to 350 beats per minute?
Atrial fibrillation
Atrial flutter
Supraventricular tachycardia
Premature atrial contraction
#11
Which of the following is a characteristic feature of third-degree heart block (complete heart block)?
Regular P-P intervals and irregular R-R intervals
Normal PR interval with widened QRS complex
Complete dissociation between atrial and ventricular rhythms
Sawtooth-shaped P waves
#12
In which type of heart block does the PR interval progressively prolong until a QRS complex is dropped?
First-degree heart block
Second-degree heart block, Mobitz type I (Wenckebach)
Second-degree heart block, Mobitz type II
Third-degree heart block (complete heart block)
#13
Which electrolyte imbalance is associated with the development of Torsades de Pointes?
Hypokalemia
Hyperkalemia
Hypocalcemia
Hypermagnesemia
#14
What does the presence of multiple premature ventricular contractions (PVCs) in a row on an ECG suggest?
Ventricular tachycardia
Ventricular fibrillation
Premature atrial contractions
Atrial fibrillation
#15
What is the typical appearance of the QRS complex in a left bundle branch block (LBBB)?
Widened QRS complex with a slurred initial deflection (rabbit ears)
Narrowed QRS complex with tall R waves in V1 and V2
Absence of QRS complex with erratic electrical activity
Normal QRS complex duration with absent P waves
#16
What is the primary treatment for ventricular fibrillation?
Defibrillation
Amiodarone
Adenosine
Cardioversion