Pauses and Irregular/Absent P Wave in Monitor Results?

[Fluffybunnyx]

I was in hospital for a week back in July due to tachycardia (about 140bpm for 6 days with ST-II depression) I was put on atenolol 25mg, later upped to 50mg and that seemed to control it pretty well. I had a 7 day monitor while the tablets were working and it only showed a few short episodes of sinus tachycardia. Fast forward to October and the atenolol wasn't really working so my GP switched it to Bisoprolol 7.5mg and booked another 7 day tape. The bisoprolol didn't really work at all. I got the second monitor results back this week and it showed mainly sinus tachycardia as high as 214bpm, as well as short runs of PSVT, ventricular bigeminy, and atrial and ventricular ectopics. It also showed 539 relative pauses of about 1.5seconds, and the cardiologist who looked at it noted irregular and even absent P waves during some of my episodes. He said something about AVNRT, but I'm more concerned about the pauses because I didn't have any on my previous 7 day tape 2 months before, I've looked online and sick sinus syndrome keeps coming up but I don't think my pauses are long enough for that to be the problem. Does anyone else have any experience with this? Im a 22 year old female, and I get palpitations, dizziness, chest discomfort and the feeling of skipped beats (which I now assume is the pauses) if thats any help :)

[2210485]

Upper end of snrt after 200 BPM tachycardia is about 2000 ms (up to a 2 second pause).

So while its probably true your pause is a bit long i see nothing to support it being "concerningly" long.

[2210485]

By upper end meaning the point intervention becomes the likely course of action.

That said, just spent the oast several hours doing some research into incidence of sss in folks your age.

Can it happen? Yes, of course.. And it is actually more prevelant then i thought, however a significant percentage of these cases have been attributed to congenital defects and diseases such as rheumatic heart disease. Familial (genetic) and idiopathic sinus dysfunction. If the pauses you describe arent occuring after an ectopic or a profound tachycardia (they occur in your natural resting rhythm) these possibilities are likely, however their clinical significance in your case is unknown.

If in the other hand the pauses are post ectopic or after the tachycardia then it could,be explained with something as simple as autonomic tone.

[Fluffybunnyx]

Ah ok thank you for this, that makes more sense. I didn't think it would be likely I had sick sinus syndrome at my age, but its best to check these things I guess.

[2210485]

Well when i said more common then expected were talking like.. About as common as being hit by a drunk driver as opposed to being struck by a bolt of lightning.

In either case its still not a judtification to spend your whole life indoors you know?

As i said though, regardless of whether the problem is just the avnrt/pvc or if you do have some sort of rare genetic sinus node disease the way wed approach it is the same.

You get the ep study, that gives us a better idea exactly whats going on.. And you perform an ablation for the tacharrhythmia.

[2210485]

Dang, phone crashed.. After i typed an entire response.. Sigh here goes again.

Its highly unlikely at your age that the problem is sick sinus syndrome.

I dont think its atrial tachycardia at over 200 (sa node reentry). I think you have 2 primary problems, avnrt and the pvc/bigeminy.

Avnrt is activated by a premature impulse, pvc or pac. Its self limiting meaning it resolves on its own, occuring in episodes of a few seconds or rarely minutes. Avnrt commonly has a rate over 200. P waves in avnrt are 'absent', abnormal and may occur before or after the qrs.

This is because in avnrt the atria and ventricles may depolarize at the same time, or one after the other on account of the av node being in the middle of the chambers.

As for your pauses i think they are more likely due to a abnormally long recovery period, which is distinct from a pause and doesnt necessarily have to accompany any significant conduction system disease. Its completely beningn so long as it doesn't accompany symptoms (such as syncope, or fainting)

As for the bigeminy it could be:
1. A reentrant mechanism (most likely)
2. An accelerated pvc with entry block
3. A single, or perhaps several exceptionally irritable idiopathic foci that give the appearence if bigeminy.

Regardless of mechanism the treatment is the same.

Basically a pac hits that fast pathway refractory period and puts you into avnrt, with a rate of 200+ and the abnormal p waves you described. After a few seconds the rhythm terminates and is followed by an exceptionally long refractory period. This causes ventricular escape/pvcs, possibly with bigeminy to follow on resumption of sinus rhythm.

As stated the treatment is the same, ep study, avnrt ablation and probable pvc ablation while theyre in there. I think once the mechanism of the ventricular phenomenon is better understood with the study its likely that some sort of connection between the 2 arrhythmias may surface.