Etopic Beat, AET, PAT and PAC

Hello,

Well, just saw the cardiologist yesterday and have been diagnosed with atrial etopic tachycardia.  It is not sustained, rather just occasionaly rins of 6 beats.  The cardiologist said that basically, I have a few cells in my atrium which occasionally fire and produce an extra beat (instead of originating from the sinus node).  He said it is 100% benign and will not hurt me in anyway... and explained the whole process of what happens, so I feel fine about it.  No treatment required as the runs are only a few beats a couple times a week.

Anyway, I do have a question.  I have read terms such as Etopic Beat, AET, PAC, PAT, SVT and PSVT.  I know what SVT and PSVT are, and AET (which is what I have... atrial etopic tachycardia... though mine is paroxysmal... intermittent and short lived).  AET is a sub diagnosis of SVT... so that is clear.  What I can't figure out is are the terms Etopic Beat, PAC and PAT just synonyms for AET>

Cheers,
Dave

[itdood]

Ectopic beat is an umbrella term (none-specific) for any sort of beat originating from a ventricular or atrial muscle cell instead of the SA node.  So PVCs, PACs are ectopic beats.  PACs (premature atrial contractions) are ectopic beats originating in the atrium muscle.

diagnosing someone with Ectopic Beats means a beat originated from a muscle cell(s) in the ventricles or the atria.  Diagnosing someone with PACs or PVCs are a bit more specific, PACs meaning ectopics in the atria, PVCs meaning in the ventricles.  These are all non-specific diagnoses.

I think where you are getting confused is the how ectopics relate to PAT or in the ventricles NSVT or VT?

an "ectopic tachycardia" like NSVT or AET is when the ectopic beats happen in a row, with no normal beats in between.  I know NSVT better, this is when a ventricular ectopic beat happens more than 3 times in a row.    Usually the ectopics happen isolated;  1, 2, or 3 in a row.  4 or more in a row now cross the line into a tachy situation and depending on how long this duration lasts more classifications follow.  hope that helps

[jolleyhearted]

So is AET that is paroxysmal just a form of PAT.

[itdood]

Hi jolleyhearted,

I don't think AET (even the 'paroxysmal' version) is a form of PAT.  The two have distinct causes.    PAT is caused by conduction pathways.  AET is caused by ectopic sources (heart muscle sources).

Paroxysmal means "short and frequent", so paroxysmal AET means short and frequent atrial ectopic tachy.    PAT means short and frequent atrial tach that comes from extra conduction pathways.

It's tempting to think of AET as a more specific category of PAT, but that's not the case.    The two both describe atrial tach but they have very different sources.

[is_something_wrong]

Was planning some days away from heart related issues, but I can't stay completely away:)

I disagree a little bit (though it's completely possible that I'm wrong :)

Supraventricular arrhytmias (SVA) more specific, supraventricular tachycardias (SVT) are, as far as I know, always "paroxysmal" (except Afib and Aflu, no doctor would allow you to go for weeks with a SVT, as heart rate >150 over time is unhealthy, and in most cases the tachycardia would stop anyway). Afib/Aflu with low ventricular rates is usually well tolerated and some people just live with them. Sinus tach is also considered a SVT, but it's (usually) not considered an arrhythmia, so let's keep this out of the discussion.

We're left with following paroxysmal SVT's (or paroxysmal atrial tachycardias, PAT)

- AV Nodal Reentry Tachycardia (AVNRT)
- Ectopic Atrial Tachycardia (AET or EAT, uni- and multifocal)
- Junctional Ectopic Tachycardia (JET)

AVNRT is the most common supraventricular arrhythmia, caused by AV nodal reentry. Unifocal AET is a "line of PACs" and is usually not noticed, because it is, like VT, defined as "3 or more extrasystoles", in this case PACs, and it's usually short runs (3-10 beats) and finished in seconds. However, it can sometimes be "sustained" (>30 secs) thus being a "paroxysmal atrial tachycardia". AET is caused by either increased automaticity (benign) or re-entry in atrial tissue (possible caused by damages). The first one is the most common in younger people.

Multifocal atrial tachycardia is a rare arrhythmia, percieved as atrial fibrillation (because it's irregular - defined as 3 or more ectopic spots firing. On ECG it looks like multiple PACs.

JET is the same phenomena, just going out from AV node instead of atrial tissue. This is a rare condition.