#1
Which of the following is a common cause of first-degree atrioventricular (AV) block?
Hypokalemia
ExplanationLow potassium levels can disrupt the conduction system of the heart.
#2
What is Mobitz type I atrioventricular (AV) block commonly referred to as?
Wenckebach phenomenon
ExplanationProgressive prolongation of the PR interval until a beat is dropped.
#3
Which medication is commonly used to treat atrioventricular (AV) blocks by increasing heart rate?
Atropine
ExplanationAtropine blocks the action of the vagus nerve, increasing heart rate.
#4
Which of the following terms is used to describe a temporary cessation of cardiac electrical activity in a patient with atrioventricular (AV) block?
Cardiac arrest
ExplanationComplete stoppage of heart activity due to electrical malfunction.
#5
Which term is used to describe the phenomenon where there is a consistent ratio of P waves to QRS complexes in second-degree Mobitz type II atrioventricular (AV) block?
2:1 block
ExplanationFor every 2 P waves, only 1 is followed by a QRS complex.
#6
In second-degree atrioventricular (AV) block, what happens to the conducted impulses?
They are delayed but all reach the ventricles
ExplanationImpulses are delayed, but some still reach the ventricles.
#7
Which ECG finding is characteristic of third-degree atrioventricular (AV) block?
Complete dissociation between P waves and QRS complexes
ExplanationNo relationship between P waves and QRS complexes, indicating complete conduction block.
#8
Which of the following is a potential cause of high-degree atrioventricular (AV) block in a young, healthy individual?
Lyme disease
ExplanationLyme disease can cause inflammation of the heart's electrical system.
#9
What is the primary concern in a patient with complete heart block (third-degree atrioventricular (AV) block)?
Bradycardia and potential hemodynamic compromise
ExplanationComplete interruption of electrical signals can lead to dangerously slow heart rates and reduced blood flow.
#10
What is the most common cause of acquired third-degree atrioventricular (AV) block?
Ischemic heart disease
ExplanationPoor blood flow to the heart can damage the conduction system, causing third-degree block.
#11
Which term describes the phenomenon where a P wave is not followed by a QRS complex in the electrocardiogram (ECG) due to complete heart block?
Dropped beat
ExplanationFailure of electrical signals to reach the ventricles, resulting in missed heartbeats.
#12
What is a potential complication associated with high-degree atrioventricular (AV) block?
Syncope or sudden cardiac arrest
ExplanationSevere blockages can lead to loss of consciousness or sudden cardiac arrest.
#13
Which of the following medications may be used to manage symptomatic bradycardia in patients with atrioventricular (AV) block?
Epinephrine
ExplanationEpinephrine can increase heart rate and improve symptoms in bradycardic patients.
#14
Which electrocardiogram (ECG) finding is characteristic of Mobitz type II atrioventricular (AV) block?
Sudden block of a conducted impulse without PR interval changes
ExplanationIntermittent blocks of conduction without progressive prolongation of the PR interval.
#15
In patients with atrioventricular (AV) block, what is the role of a temporary pacemaker?
To temporarily support the heart's electrical activity
ExplanationTemporary pacemakers provide electrical impulses to maintain heart function until permanent treatment can be initiated.
#16
What is the primary goal of treatment in a patient with symptomatic second-degree Mobitz type II atrioventricular (AV) block?
Insert a permanent pacemaker
ExplanationTo ensure consistent electrical signals to the heart, a permanent pacemaker may be necessary.
#17
Which electrolyte imbalance is commonly associated with atrioventricular (AV) blocks?
Hypomagnesemia
ExplanationLow magnesium levels can disrupt normal heart rhythm and conduction.