Pseudo Pacemaker syndrome

[progers]

Does anyone know anything about this? I have had episodes of "Atriocentricular dissociation" which means my ventricles and atria are sometimes out of sync. I had to spend the night in hospital the other week until to settled. I have been told that it can be cause by beta blockers, other meds, and even disturbances to the electrical conduction of the heart after myectomy. A similar thing, pacemaker syndrome, can be caused by certain kinds of pacing. The symptoms parallel those of heart failure.

It is apparently very treatable with a pacemaker, and I am getting an ICD on the 28th.

Thanks,

Paul

[Reenie]

I don't know anything about this, but it sounds similar to something one of my cousins is currently going through, albeit for much different reasons than you. He had Wolf Parkinson-White syndrome and had surgery to correct it, but ever since his heart rate has been odd and the doctors are deciding if he needs a pacer or not. Apparently they told him that his heart might have to "relearn" how normal conduction should go from the SA node through the AV node because his hasn't functioned normally in years, if ever.

[Pam Alexson]

Paul I think.. this is also ??called heart block?? Did you pass out?

As I understand heart block can progress ... in degrees .... 1st degree is not a big issue but, progressing to complete is an issue. Many, or most of us have assynchrony of the ventricles after myectomy and of course that is tied in w/ the LBBB that usually occurs after myectomy due to the inevitable tampering w/ electrial system of our heart during the shaving.

Now the atria as you state can have a dissociation equating to the heart block. You are right the pacer can resynchronize... if you will THE PACKAGE. I have also learned that our needed meds can contribute to this dissociation. My EP has talked to me about RST( resynchronization therapy). that is for my ventricles .. I take sotalol to prevent a-fib and that works and may have also helped prevent the advancing of heart block BUT I am not sure as my heart failure issues have been worse requiring a spike in med doses.

I will be interested to hear all that you learn as some of us are heading in a sort of squiggly path along w/ you. Boy these HCM heart issues can really get complex can't they? It is all valuable though as we learn about these issues. Thanks for sharing and informing us ..feel better.

Pam

[progers]

HI Pam,

Yes, you and I and a few others do seem to be on a rather unkown path! I did not pass out but have experienced pre-syncope several times recently. Is heart block a generic term for conduction disturbances, which includes AV dyssynchrony etc.?

Almost everyday I experience dizziness, disorientation and confusion, even when I am in my car sitting down! I can go from feeling completely normal, to feeling washed out, confused, nauseous and like I am going to die in the space of 3 minnutes. Sh*t, I am only 38 and have an 8 week old baby and a 3 year old to take care of! I was supermarket the other day just standing there and not know where the **** I was or what I was doing.

But I think I am getting some answers. I am clearly not having heart failure all the time, else my lungs, BNP, fluid levels, jugular venous pressure would all indicate it - and they don't. Something else is causing sudden declines to my cardiac output.

I am having a holter on Tuesday and the ICD put in next on the 28th. I may have definitive answers soon.

Cheers,

Paul

[Pam Alexson]

Atrioventricular (AV) dissociation is an electrocardiographic syndrome; a descriptive term for a variety of conditions of abnormal cardiac conduction which all feature independent function of the atria and ventricles. AV dissociation can be subclassified as AV dissociation by default (an independent ventricular pacemaker responds to slowing of the dominant atrial pacemaker) versus AV dissociation by usurpation (acceleration of a latent pacemaker takes control of cardiac conduction by exceeding the intrinsic atrial rate). Inclusion of third degree AV block (complete heart block) as a manifestation of AV dissociation is controversial, yet is functionally appealing in that this disorder also features independent activity of the atria and ventricles.

Third-Degree Heart Block

Third-degree atrioventricular block
In third-degree AV block (complete AV block, no AV conduction), no atrial impulses reach the ventricles, and ventricular rhythm is maintained by a subsidiary pacemaker. Since subsidiary pacemakers must be below the level of block, their location is in part determined by the site of block. In third-degree AV nodal block, the ventricular rhythm is usually maintained by pacemakers in the AV junction with resultant narrow QRS complexes. In third-degree AV block localized to the bundle branches, ventricular rhythm is maintained by a pacemaker in the Purkinje fibers, with resultant wide QRS complexes. The junctional pacemaker rate is usually faster (40–80 beats/min) compared with the peripheral Purkinje network (20–40 beats/min).
When third-degree AV block occurs at the AV node, it can result from increased parasympathetic tone associated with inferior infarction, from toxic drug effects or from damage to the AV node. Third-degree AV block with a junctional escape rhythm is usually transient and is associated with a favorable prognosis. When third-degree AV block occurs at the infranodal level, it is most often due to block involving both bundle branches. This indicates the presence of extensive infranodal conduction system disease. When it results from coronary atherosclerosis, it is usually associated with extensive anterior myocardial infarction. It usually does not result from increases in parasympathetic tone or from drug effects.

Treatment
The major interventions are atropine, transcutaneous pacing, catecholamine infusions (dopamine or epinephrine), and transvenous pacemaker. Isoproterenol is rarely indicated.

Summary of ECG criteria
QRS: Generally normal looking. When block occurs at the AV node or bundle of His, the QRS complex will appear normal. When block occurs at bundle branch level, the QRS complex will be widened.
P waves: Normal
Rate: The atrial rate will be unaffected by third-degree AV block. The ventricular rate will be slower than the atrial rate. With intranodal third-degree AV block, the ventricular rate is usually 40 to 60 beats/min; with infranodal third-degree AV block, the ventricular rate is usually less than 40 beats/min.
Rhythm: The atrial rhythm is usually regular, although sinus arrhythmia may be present. The ventricular rhythm will be regular.
PR interval: Since the atria and ventricles are depolarized from different pacemakers, they are independent of each other, and the PR interval will vary.
Atrioventricular dissociation
AV dissociation is a rhythm in which atrial and ventricular activation occurs from different pacemakers. The atrial rhythm can be of sinus origin or from any of the atrial arrhythmias listed previously. Ventricular activation may be from either junctional or lower pacemakers. Third-degree AV block is one form of AV dissociation. The latter, however, is common in the presence of intact AV conduction. AV dissociation in the presence of intact AV conduction can occur when rates of subsidiary pacemakers, junctional or ventricular, exceed the atrial and there is associated AV block, as seen in ventricular tachycardia. This contrasts with AV dissociation during third-degree AV block, where atrial rates usually exceed ventricular rates.





I don't think the terms are interchangeable BUT not sure. Heart block has different degrees and is not just one definition that describes it. There is 1st degree, 2nd degree , 3rd degree and complete heart block.

[progers]

Hi Pam,

As usual, you have delivered on the info! Just have to wait and see if the pacemaker part of the ICD helps me.
By the way, I went surfing for two hours today and felt pretty good, considering. We have beautiful fall weather here - about 77 F during the day, no wind, blue ocean and clear, star-filled nights! My new baby has just fallen asleep and I have just finished story time for my 3 year old. Time to relax.....

Paul

[Reenie]

Paul, it sounds lovely there. Enjoy the little babies while you've got them. They do grow up so fast.

[Isis1946@aol.com]

This is gonna be a long post, but, let's see if I can cut through some of this for you. AV dissociation is, as has been already said, a difference in the timing of the beat of the upper chambers of the heart (Atria) and the lower chambers of the heart (ventricles). It is commonly believed that all chambers of the heart beat at the same time in a normal heart. Not true, there is actually a micro-millisecond where the top beats before the bottom. Mild AV dissociation shows up on a cardiogram as a difference in length of time from the P-wave (the tiny first "bump" on the line - which indicates that the top chambers have fired or beaten) and the start of the QRS complex (the larger V,W looking squiggle on the line which indicate that the bottom chambers have fired). This difference in length of time varies from heart beat to heartbeat. This AV dissociation is not necessarily a reason to treat. Many people come by it honestly and live their entire lives without problem.

First Degree Heart Block is also measured by the length of time between the P wave and QRS complex, but in this type of block the length of time is always the same and exceeds a pre-determined measurement. Again, this type of block does not always need treatment, but does need to be watched.

Second Degree Heart Block is more complex, measured in the same way, but here, the upper and lower chambers of the heart beat in synchrony only some of the time, and some of the time the top beats do not travel to the bottom the way they are supposed to.

Third Degree Heart Block, also known as Complete Heart Block occurs when the top and bottom chambers are beating independently of one another all of the time. Yes, this is what happens also in Atrial Fib, but in A-Fib the upper chambers are beating irregularly and the lower chambers are also beating irregularly. In Complete Heart Block, the upper chambers and the lower chambers are beating regularly, but independently of one another.

WOW!!! Now that everyone's head is spinning! Pacemakers correct all of the above by electrically stimulating either the upper or lower chambers or both, depending on the placement of the wires. In the normal heart, the signal to beat, arises in the upper right chamber and travels down the wall between the larger lower chambers. If you have had myectomy, the electrical pathways in that wall can be disturbed.

Most of us hypertrophs have ICDs these days because of our prediliction (?sp) to ventricular fib, which is fatal. ICDs pace, cardiovert, and shock as necessary.

An example of how complicated this can be, even for doctors: my first pacemaker battery failed over the Fourth of July weekend in 2006. I was in Gettysburg, PA, some 40 miles from home. Because I had suffered a broken wire some years previouly, I knew from the way I felt exactly what was happening. I went to the local ER, and was asked by the triage nurse why I was there. I said, "Pacemaker failure." He said, "NO! Why are you here?!" I repeated, "Pacemaker Failure." Again, he said, "No, why are you here?!" Really confused, I answered, "Pacemaker Syndrome?" He got really annoyed, and said, "Do you have chest pain?!!!" AH, then came the dawn, he was looking for symptoms, not a diagnosis. So, I finally get checked in and hooked up to the monitor, and the doctor comes over and says, "Maam, you are pacing!" I had to get up, turn around and look at the monitor, and point out to him that I was pacing the bottom two chambers of my heart only and not the top chambers at all. I showed him how the P wave spike was missing and the total pulse rate was too slow for my pacemaker. After he said, "OH!" , I requested transfer to Harrisburg Hospital, where everybody believed me. Perhaps the moral of this story is to stay away from Gettysburg over the reinactment weekend!!!!

[Reenie]

Oh good grief! I'm glad you knew what you were talking about! I'll remember to stay out of Gettysburg over the 4th. ;) I'm glad all turned out all right with you.

Thanks for the information on heart block. I learned something today.

[progers]

Pam,

Scary! When I had to spend the night in hospital three weeks ago because of "junctional rhythms", the ER doc spoke to my cardiologist/EP who said that my atenolol was probably slowing my heart rate down too much and so causing junctional rhythms. The ER doc relayed this info to me. Clearly, the stupid thing to do at that point would have been to take more atenolol. But that is exactly what the ward nurse tried to get me to do later, even after I told her it probably wasn't a good idea. I protested and the nurse got a little pissy, saying something about "well I tried to get you to take it" before walking out.

When I told my doctor this the next day he was amazed and said "it really is scary out there", in reference to the numerous stubborn and pigheaded medical professionals out there who risk our lives because of their egos and/or inability to listed to patients.

Cheers,

Paul

[Pam Alexson]

Paul... read page 56

It is interesting to take out the part about obstruction ( because you..me and others do not have one anymore) and read about heart block and other issues that effect HCM hearts. My heart is now described as concentric hypertrophy is yours also?

http://www.anakarder.com/sayilar/34/55-60.pdf

[Bucky]

Severe concentric hypertrophy was my diagnosis (along with HCM), but when I checked with HCMA (the mother ship) Lisa Salberg said she wished they wouldn't use the word severe. The severe part refers to the fact that the entire ventricle is thickened as opposed just one portion of the ventricle. Also the severe does not refer to the actual measurement of the thickness as I understand it. Of course I freaked when I saw the severe part.........!!!!!!!!!!!!!!!!!!!!!!!!!

bucky

[progers]

Hi Pam,

Yes, my latest echo states "marked concentric left ventricular hypertrophy". I don't know what "marked" means, but my posterior wall was 1.4 cm in July 2007, which apparently was a favourable result of remodelling following my myectomy (not sure what is was previously, but presumably > 1.4 cm).

I had seen that article but must have missed the info on heart block etc. Very interesting. It reinforces what I, and my docs, think might be happening to me. Atenolol, combined with myectomy (and some left bundle branch block, and maybe other effects of HCM), causing bradychardia and AV dissociation. Might explain why I almost fainted just sitting at my desk today at work: sudden difficulty breathing, confusion and light-headedness, fealing nauseous and weak.

My docs seem to think my new ICD will prevent these "heart block" types of symptoms. I can only pray.....Has anyone had significant benefit in such circumstances?

Pam, are you paced to prevent things like AV dissynchrony?

Take care,

Paul


My issues are undoubtedly related to AV dyssynchrony/heart block. I just had to come home from work due to sudden, non-exertional, light headedness, nausea, weakness, and difficulty breathing. I think my heart rate is also down

[Pam Alexson]

Hi Paul...I know I am paced on demand and do about 40% pacing over the 3 month read or interrogation. As I have asynchrony of the ventricles and only 1st degree a/ v block I do not believe I am at that need presently.

I can find that my PW was 1.3 cm in 2001 shortly after initial dx and now 4 1/2 years post myectomy I am at .85cm. I am not too sure of what this means other then yes there has been remodeling and my PW is rather thin now. I guess sometimes I fear that it is heading the other way and the thinning is a beginning to dilation. As they now list me as mild concentric hypertrophic cardiomyopathy ...you see why I think this way. I was never extremely thick 2.0 cm at time of myectomy( 2003) but, the readings varied from 1.3( 2000) ..1.5..1.8..2.0 ...in 2003. As most of the syncope was probably due to the obstructive gradient of 200++ on valsalva it was reasonable to see why I passed out and had constant pre-syncope while trying to move about. The readings I reviewed in my chart also stated that they could not rule out that the severe diastolic dysfunction may also contribute to syncope/ pre-syncope, episodes. As I still get fuzzy sometimes if I push I think that is still an issue OR... it could be advancing heart block right?? There was also marked(LOL ..there's that word again), ischemia in lateral apex portion of the myocardium. Left ventricular end diastolic pressure was 40 mm hg. I cannot find that info current but read that my pulmonary arterial pressures are 40-50 mm hg= moderate pulmonary hypertension..must be why talking wears me out I get winded and I sound very raspy and congested after a bit. My right ventricle systolic pressure is 30 mmhg.

Marked means significant. So you are still considered thick in an all around( concentric) fashion as opposed to asymetric (in the bulging septal area.) I do believe the pace maker is going to give you some return to quality ..I am sorry you are having these bad spells presently.

So many #'s so much to ponder....

Let us keep hearing how you do.. we all learn something new everyday about HCM from each others journey.

Pam

[Pam Alexson]

Doug/ Bucky, I know the word severe is severe.... they should have said marked that describes degree/ amounts in these cases. Severe evokes fear and sounds permanently doomed.
It just reminds us that people are adding these words of description and they probably did not get an A in vocabulary and word definition. LOL

Pam

[progers]

Sure will Pam. Are you sure you do not have rhythm problems which contribute to your symptoms? I suppose you would know when they interogate your ICD?? An LV end-diastolic pressure of 40 mmHG seems high. When was this measurement taken? Heart rhythm problems/dyssynchrony can cause elevated LVEDP and high atrial pressure, leading to congestion and a-fib.

Take care,

Paul

[Pam Alexson]

OHHH yes, Paul.

I started having a-fib recurring in 2006. It WAS detected on interrogation of my devise and I was being coaxed into accepting that if it continued to show up that I needed to be on coumadin. It locked in on me in Nov.2006 and I did not self convert. My ventricle wire went bad and things fell apart, I was in CCU until they got another one in. I could not be cardioverted at the time and had to wait a month and stay in a-fib until I was regulated on coumadin. It happened again in April and I had to have a TEE because someone forgot to properly oversee my coumadin correctly. With no clot visible they cardioverted me again.
That was it for me, I made a plan immediately w/ my HCM specialist .. he put me inpatient and started me on Sotalol. That was May of 2007. I have been lucky as some others here have been . IT IS WORKING.

I know that it is talked about that a-fib is manageable and many have chronic a-fib. I was not ready to let that be the case for me ..I know that HCM hearts can change/ remodel over time and that can happen just because that is how HCM is . Also I know that different mechanisms ; a-fib is one of them , can also influence change / remodeling in the heart. My goal is to intervene quickly and help to halt or stall those other changes that we may be able to intervene with..you know?

The pressure reading, 40 mmhg was done before myectomy 2003. These increased pressure issues is why I am told I have severe diastolic dysfunction. My heart was described as being like 2 hard leather straps beating together. My atriums are both moderately dilated. Last read in 2006 on my left atrium diameter was 46mm. 46 for me was enough to create changes and start a-fib. As you know it could vary as what diameter would insight a-fib in another's heart. The elevated pressure in my right ventricle is why my inferior vena cava is dilated.. You see why again I think about dilation...will it stop here or is it destined to continue?

So that is what I know.

Pam