Kate - Mobitz /Wenckebach, afib

Kate,

Following onto this thread and bringing it forward: <[www.afibbers.org];

Here is some background, my comments are at the end.

[en.wikipedia.org]
Second degree AV block

Second degree AV block is a disease of the electrical conduction system of the heart. It refers to a conduction block between the atria and ventricles.

The presence of second degree AV block is diagnosed when one or more (but not all) of the atrial impulses fail to conduct to the ventricles due to impaired conduction.

Types

There are two distinct types of second degree AV block, called Type 1 and Type 2. The distinction is made between them because type 1 second degree heart block is considered a more benign entity than type 2 second degree heart block.

Type 1 (Mobitz I/Wenckebach)

Type 1 Second degree AV block, also known as Mobitz I or Wenckebach periodicity, is almost always a disease of the AV node.

Mobitz I heart block is characterized by progressive prolongation of the PR interval on the electrocardiogram (EKG) on consecutive beats followed by a blocked P wave (i.e. a 'dropped' QRS complex). After the dropped QRS complex, the PR interval resets and the cycle repeats.

One of the baseline assumptions when determining if an individual has Mobitz I heart block is that the atrial rhythm has to be regular. If the atrial rhythm is not regular, there could be alternative explanations as to why certain P waves do not conduct to the ventricles.

This is almost always a benign condition for which no specific treatment is needed.

Type 2 (Mobitz II)

Type 2 Second degree AV block, also known as Mobitz II is almost always a disease of the distal conduction system (His-Purkinje System). Although the terms infranodal block or infrahisian block are often applied to this disorder, they are not synonymous with it. Infranodal block and infrahisian block are terms which refer to the anatomic location of the block, whereas Mobitz II refers to an electrocardiographic pattern associated with block at these levels.

Mobitz II heart block is characterized on a surface ECG by intermittently nonconducted P waves not preceded by PR prolongation and not followed by PR shortening. The medical significance of this type of AV block is that it may progress rapidly to complete heart block, in which no escape rhythm may emerge. In this case, the person may experience a Stokes-Adams attack, cardiac arrest, or Sudden Cardiac Death. The definitive treatment for this form of AV Block is an implanted pacemaker.

[edit] Symptoms

Most people with Wenckebach (Type I Mobitz) do not show symptoms. However, those that do usually display one or more of the following:

* Light-headedness
* Dizziness
* Syncope (Fainting)


From the Wiki discussion page -
[econd_degree_AV_block" rel="nofollow">en.wikipedia.org]
(by the way, Jackie, it is always interesting to read the discussion page of a Wiki entry)

Mobitz Type II heart block is characterized on a surface ECG by a fixed PR interval, with a series of cycles consisting of one normal P-QRS-T cycle preceded by a series of non-conducted P waves (i.e. P waves not followed by QRS complexes). Each repeating Mobitz series has a consistent P:QRS ratio (2:1, 3:1, 4:1, etc.). Higher conduction ratios (4:1, 5:1, etc.) indicate increased severity of the block, and are known as advanced Mobitz block

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So the question is - is your current situation caused by your afib, by your heart block, or both.

By the way, is your afib now paroxysmal, persistent or permanent?

Here are some possibliities:

1. Your heart block has stayed constant over time, and you've gotten afib recently.

2. You heart block has gotten worse over time, and you've gotten afib recently.

If #1 is true, then afib is most likely causing your problems. If #2 is true then both afib and the block are likely causing your problems.

From the above - "The definitive treatment for this form of AV Block is an implanted pacemaker."

An ablation may be in order for the afib. A pacemaker may be in order for the block. But you need to figure out what is causing your symptoms – the afib, the block or both.

Just a thought.

George

In the thread linked above I proposed that Kate's diagnosed AV block may never have actually existed. Kate's ablation should not have affected an AV heartblock. Kate's steady heart rate for ten years after her ablation (even though her heart rate would have varied widely during her athletic activities during the ten years) argues that there never was an AV block.

If so, she probably now just has plain old a-fib.