Understanding AV Blocks

What is an AV block?

In an AV block, the QRS complexes will be of _____ duration if the block is located at the level of the AV node or bundle of His.

In an AV block, the QRS complexes will be of _____ duration if the block is located at the level of the bundle branches.

What is a first-degree AV block?

What is a second-degree AV block?

What component of the ECG is key to identifying the type (degree) of block present?

What two components of the ECG are key to identifying the location of block present?

What are the characteristics of first-degree AV block?

Where is the location of the conduction disorder in a first-degree AV block?

Identify this strip: Sinus bradycardia with AV block

Identify this strip: NSR with AV block

Identify this strip: Sinus arrhythmia with AV block

This arrhythmia is associated with inferior wall MI, increased vagal tone, drug effects (calcium channel blockers, beta blockers, and digitalis), hyperkalemia, and degenerative changes due to aging.

This arrythmia does not require any specific treatment but should be observed for progression to more serious block.

What is also known as Wenckebach?

What are the characteristics of Mobitz I (second-degree AV block)?

Where is the conduction disorder located in Mobitz I (second-degree AV block)?

Identify this strip: Mobitz I AV block

This arrhythmia is associated with inferior wall MI, increased vagal tone, effects of medications (calcium channel blockers, beta blockers, and digitalis), and hyperkalemia.

This arrhythmia may progress to higher degree of AV block under certain conditions, but generally not the case.

This arrhythmia is usually temporary and resolves spontaneously.

What two components of the strip are used to differentiate between Mobitz I and nonconducted PAC?

MOBITZ I/NONCONDUCTED PAC: abnormal p-wave/different from sinus beats

MOBITZ I/NONCONDUCTED PAC: occurs prematurely; P-P regularity interrupted

MOBITZ I/NONCONDUCTED PAC: P wave is normal/same as sinus beats

MOBITZ I/NONCONDUCTED PAC: P wave occurs on time; P-P regularity unchanged

MOBITZ I/NONCONDUCTED PAC: PR interval of basic rhythm varies

MOBITZ I/NONCONDUCTED PAC: PR interval of basic rhythm remains constant

Identify this strip: Mobitz I pattern with dropped beats

Identify this strip: Premature P wave with no QRS complex

This arrhythmia is usually asymptomatic and requires no tx; if Pt is symptomatic and ventricular rate is slow, symptomatic bradycardia protocols should be followed (atropine!); discontinue drugs causing block

What is characterized by failure of some sinus impulses to be conducted to the ventricles?

In what two places can the conduction disorder be located in a Mobitz II (second-degree AV block)?

If the block is located in the bundle of His in Mobitz II (second-degree AV block), the QRS complex will be of _____ duration.

If the block is located in the bundle branches in Mobitz II (second-degree AV block), the QRS complex will be of _____ duration.

Identify this strip: 2:1 AV conduction block

Identify this strip: 2:1 and 3:1 AV conduction block

This arrhythmia has the potential to progress suddenly to third-degree AV block or ventricular standstill with little to no warning.

This arrhythmia is associated with anterior wall MI, acute myocarditis, degeneration of electrical conduction system as seen in the elderly, and Stokes-Adams attacks.

What are syncopal episodes associated with Mobitz II and 3rd degree AV block

What is the treatment for Mobitz II (second-degree AV block) and third-degree AV block?

True or False: Atropine is not recommended for treatment of Mobitz II (second-degree AV block) or third-degree AV block.

In a third-degree AV block, the _____ are usually paced by the sinus node.

In a third-degree AV block, the _____ are usually paced by a junctional or ventricular pacemaker site.

In what three places can the conduction disorder be located in a third-degree AV block?

If the block is located in the AV node or bundle of His in third-degree AV block, the QRS complex will be of _____ duration.

If the block is located in the bundle branches in third-degree AV block, the QRS complex will be of _____ duration.

Identify this strip: Independent P waves and QRS complexes

This arrhythmia has the potential to progress suddenly to ventricular standstill with little to no warning.

This arrhythmia is associated with inferior wall or anterior wall MI, Lyme disease, digitalis toxicity, degeneration of electrical conduction system, and Stokes-Adams attacks.

In a third-degree AV block with _____ wall MI is usually stable and resolves on its own.

In a third-degree AV block with _____ wall MI is usually unstable and may require permanent pacing.

Describe a first-degree AV block.

Describe a second-degree AV block.

List the characteristics of first-degree AV block.

Identify this strip: sinus bradycardia with first-degree AV block.

Identify this strip: NSR with first-degree AV block.

Identify this strip: sinus arrhythmia with first-degree AV block.

First-degree AV block is associated with what conditions?

Does first-degree AV block require any specific treatment?

What is Mobitz I (second-degree AV block)?

List the characteristics of Mobitz I (second-degree AV block).

Identify this strip: Mobitz I (second-degree AV block).

Mobitz I (second-degree AV block) is associated with what conditions?

Can Mobitz I (second-degree AV block) progress to higher degree of AV block?

How long does Mobitz I (second-degree AV block) typically last?

Identify this strip: Mobitz I.

Identify this strip: nonconducted PAC.

In general, does Mobitz I (second-degree AV block) require treatment?

Identify this strip: Mobitz II with 2:1 AV conduction.

Identify this strip: Mobitz II with 3:1 AV conduction (one P wave hidden in T waves).

Identify this strip: Mobitz II with 2:1 and 3:1 AV conduction.

Can Mobitz II (second-degree AV block) progress to a more serious AV block?

What are Stokes-Adams attacks?

How is Mobitz II (second-degree AV block) treated?

T/F: Atropine is not recommended for treatment of Mobitz II (second-degree AV block) or third-degree AV block.

Identify this strip: third-degree AV block.

Can third-degree AV block progress to a more serious condition?

Describe Mobitz I (second-degree AV block).

How is a Mobitz II (second-degree AV block) characterized?

What is the treatment usually for Mobitz II (second-degree AV block) or third-degree AV block?

Atropine is recommended for treatment of Mobitz II (second-degree AV block) or third-degree AV block.