#1
Which of the following is a common cause of bradycardia?
Hyperthyroidism
Hypertension
Hypoxia
Hypokalemia
#2
Which of the following is NOT a cause of sinus bradycardia?
Increased intracranial pressure
Hypothyroidism
Hypothermia
Hyperkalemia
#3
Which of the following conditions is NOT commonly associated with sinus bradycardia?
Athletic training
Hypoxia
Sinus tachycardia
Inferior myocardial infarction
#4
Which of the following medications can exacerbate bradycardia in patients with heart block?
Beta-blockers
Calcium channel blockers
Angiotensin-converting enzyme (ACE) inhibitors
Diuretics
#5
Which of the following is a common cause of sinus bradycardia in athletes?
Hypothyroidism
Hyperkalemia
Vagal overactivity
Acute myocardial infarction
#6
In which type of heart block does every atrial impulse fail to conduct to the ventricles?
First-degree heart block
Second-degree heart block
Third-degree heart block
Sinus bradycardia
#7
Which of the following medications is commonly associated with causing bradycardia?
Atropine
Epinephrine
Isoproterenol
Digoxin
#8
What is the characteristic ECG finding in third-degree (complete) heart block?
P waves and QRS complexes have a 1:1 ratio
P waves and QRS complexes have a 2:1 ratio
P waves and QRS complexes have no relationship
P waves and QRS complexes occur simultaneously
#9
Which of the following conditions can cause bradycardia due to increased vagal tone?
Myocardial infarction
Asthma exacerbation
Carotid sinus massage
Pulmonary embolism
#10
Which type of second-degree heart block is characterized by a consistent PR interval with occasional dropped QRS complexes?
Mobitz Type I (Wenckebach) second-degree heart block
Mobitz Type II second-degree heart block
High-grade atrioventricular (AV) block
Bundle branch block
#11
What is the primary mechanism through which hypothermia causes bradycardia?
Increased sympathetic tone
Increased parasympathetic tone
Increased circulating catecholamines
Decreased cardiac contractility
#12
What is the ECG hallmark of Mobitz Type II second-degree heart block?
Progressively lengthening PR intervals until a QRS complex is dropped
Intermittent non-conducted P waves with a constant PR interval
Irregularly irregular rhythm with no discernible pattern
Complete absence of atrial activity
#13
Which of the following electrolyte imbalances is commonly associated with heart block?
Hypercalcemia
Hypophosphatemia
Hyperkalemia
Hypermagnesemia
#14
Which type of heart block is characterized by a progressively lengthening PR interval until a QRS complex is dropped?
First-degree heart block
Mobitz Type I (Wenckebach) second-degree heart block
Mobitz Type II second-degree heart block
Third-degree heart block
#15
What is the effect of hypercalcemia on the cardiac conduction system?
Increases automaticity of the SA node
Shortens the PR interval
Prolongs the QT interval
Reduces atrioventricular nodal refractoriness
#16
Which of the following is a feature of sick sinus syndrome?
Sinus bradycardia during sleep
Tachycardia-predominant episodes
Consistently normal heart rate variability
Stable heart rate during exercise
#17
Which electrolyte abnormality is commonly associated with the development of heart block in patients with digoxin toxicity?
Hypercalcemia
Hyperkalemia
Hypomagnesemia
Hypophosphatemia