Heart Block

[123qwerty]

I'm writing part of a paper on AV heart block and was wondering what kinds of heart block there are. My patient had 3rd degree AV block, but I wasn't able to find enough information for how much I need to write on that so I'm writing about the other types as well. What I found so far is 1st degree AV block, 2nd degree type 1 and 2, and 3rd degree. One source I have says a bundle branch block is also in this category, but other places I have looked don't mention it. Does BBB belong in this category? Also what is the difference between 2nd degree type 2 and a BBB? From what I have read they both occur below the bundle of His.

[Rose_Queen, BSN, MSN, RN]

This site might be able to help you out:

ECG Learning Center - An introduction to clinical electrocardiography

It's been some time since I've had my EKG interpretation course, and I don't routinely interpret EKGs at work (heart surgery; pretty much all of my patients are in either v. fib while on bypass or paced afterward, plus anesthesia is the one with the monitor in front of them). I also can't remember where BBB are classified, although the site I gave above does state this:

Type II AV block is almost always located in the bundle branches, which means that the QRS duration is wide indicating complete block of one bundle; the nonconducted P wave is blocked in the other bundle.

Hope this helps at least a little!

[Esme12, ASN, BSN, RN]

Heart block.....Heart Block

I also like the Cleveland clinic resources.....Heart Block

I always taught this poem

[Esme12, ASN, BSN, RN]

123qwerty said:

I'm writing part of a paper on AV heart block and was wondering what kinds of heart block there are. My patient had 3rd degree AV block, but I wasn't able to find enough information for how much I need to write on that so I'm writing about the other types as well. What I found so far is 1st degree AV block, 2nd degree type 1 and 2, and 3rd degree. One source I have says a bundle branch block is also in this category, but other places I have looked don't mention it. Does BBB belong in this category? Also what is the difference between 2nd degree type 2 and a BBB? From what I have read they both occur below the bundle of His.

Well for the most part 1st 2nd and 3rd degree blocks are the AV node itself. BBB involve the bundle of HIS

Quote

The electrical activity of the heart starts in the sinoatrial (SA) node in the upper chamber (atrium) and travels through the atrioventricular (AV) node to reach the lower chamber (ventricles). Heart block may occur at any point along this electrical pathway. Heart block of the AV node can be of several types, and a doctor generally can diagnose these by looking at the person's electrocardiogram (EKG, ECG).

What is atrioventricular (AV) block?

First-degree AV block

In first-degree block, the electrical impulses take longer to travel between the upper chamber (atrium) and lower chamber (ventricle) of the heart. This type of heart rhythm may or may not be associated with a slow heart rate.

It does not usually require treatment. But this type of heart block may raise your risk of heart rhythm problems, such as atrial fibrillation.

Second-degree AV block

In second-degree heart block, some of the electrical impulses are blocked between the upper and lower chamber of the heart. These electrical impulses may or may not have a clear pattern. The blocking of the impulse can come and go, resulting in "dropped heart beats." A second-degree type II block may progress to complete or third-degree heart block.

Second-degree heart block can be categorized into two types:

• Mobitz type I block (also called Wenckebach) usually occurs in the AV node. It is common in young, healthy people (especially during sleep). It usually does not cause symptoms and rarely requires treatment.
• Mobitz type II block usually occurs below the AV node in other conduction tissue. It may be part of aging. It is also seen in people with significant heart disease or during a large heart attack. It may cause lightheadedness or fainting (syncope). And it may progress to complete heart block. This type frequently requires a pacemaker.

Complete or third-degree block

In third-degree heart block, all of the electrical impulses are completely blocked between the upper and lower chambers of the heart. When this occurs, the atria and ventricles beat at completely different rates.

Complete heart block is caused by the aging process, medicines, heart attacks, infiltrative heart diseases (amyloidosis, sarcoidosis), and infectious diseases (endocarditis, Chagas' disease). It may also occur after heart surgery and can be present from birth (congenital).

Complete heart block frequently causes symptoms of lightheadedness or fainting and usually requires the placement of a permanent pacemaker. People who are born with complete heart block (an uncommon congenital condition) often have no symptoms and may not need treatment initially. But eventually they almost always require pacemaker placement.

What is bundle branch block?

Bundle branch block can affect the heart’s rhythm. The heart has structures, like wires, that are called bundle branches. They are part of the heart's electrical pathway. When a branch is diseased, it is called "blocked," because the electrical signals can't travel down the branch.

Some people with bundle branch block don’t have any symptoms and don’t need treatment. But when a block causes the heart to beat too slowly, it can cause symptoms such as tiredness and fainting spells. A pacemaker may be used to get the heartbeat back to normal.

https://www.cardiosmart.org/Healthwise/te71/44ab/c/te7144abc

[Esme12, ASN, BSN, RN]

ECG Rhythm Analysis - Life in the Fast Lane ECG Library

[icuRNmaggie, BSN, RN]

We are seeing an increase of patients who have been treated for Lymes disease coming in with third degree heart block.

If your topic is complete heart block, which is also called AV dissociation, there is a great deal of information out there about treatment.

Start with your ACLS book. Write about transcutaneous pacing, transvenous pacemakers (remember that the millivolt setting senses the intrinsic rhythm and milliamps are the amount of energy required to produce capture, which means it produces a QRS) and permanent pacemakers. This is a great topic!

[psu_213, BSN, RN]

Also, think about the words/abbreviations in play.

AV block…what does AV stand for? What is happening to the electrical impulses of the heart there? What does it mean if there is a block in the signal there? What would it look like on an EKG.

Bundle branch block…what are the bundle branches, and where are they? If the signal is blocked through those bundles what would it look like on an EKG?

Using the resources above, and thinking about the terms, do you see a difference between AV blocks and bundle branch blocks?