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Date of last update: 10/20/2017.

Forum Name: Cardiology Diagnostics

Question: Is this really an RBBB? Is this important?

 d.soares - Thu Sep 18, 2008 8:59 pm

I've done a ECG past month, but I most likely won't be able to have a cardiologist to take a look at it and really explain it to me until some day in the next month, or maybe somewhat later (public health system constraints).

The ECG was indeed analyzed by a doctor, whose specializations are "intensive medicine" and "internal medicine", but I've never met him face to face, I've only received the ECG with his signature on.

His interpretation of the data differed somewhat from the computer's "interpretation". The values that came printed with the ECG are:

vent. rate 69 bpm
PR int. 134 ms
QRS dur. 108 ms
QT/QTc int. 392/ 412 ms
P/QRS/T axis 34/69/18°
RV5/SC1 amp. 1.595/ 0.735 mV
RV5+SV1 amp. 2.330 mV

The doctor's numbers, on a pre-printed paper with underlines:
MCF: 60 bpm
Pri: 0,13 seg
QRS 0,11 seg

Conclusion: 1 - right bundle branch block; 2 - Alteration of the ventricular repolarization on the anterior wall

And a scan of the ECG itself is here:


I'm a bit suspicious of the V1 lead. Whereas I and V6 look reasonably like the samples on [url=]this web page[url], I think that the V1 looks somewhat more like the LBBB one. :(

And also there's this discrepancy on the QRS duration between the doctor and the machine. If the machine is right, QRS is ok and there's no BBB of any sort, right? Searching a bit about it on the net I've read vague statements such as "don't rely on the machine's results" (not directed to me, but on ECGs in general), but I wonder why, and where these extra milliseconds from the human read would have came from...

I'm somewhat scared with the whole thing, I've read that RBBB ranges from something that's harmless to something that commonly results in sudden death among young people with it. I've some eventual mild symptoms, what I think that is presyncope (the best example/description is that I'd be reading and would miss the line for about a second, as if someone had shaken the book of my hand; it's somewhat like falling asleep too, which is scary when I'm actually trying to sleep) and even sporadic, but quite light pain on my chest, and some days I feel somewhat as if I were wearing a tight sleeve on the left arm alone. I once (2006) went to the emergency for these symptoms , had an auscultation and ECG, and the doctor said that it was nothing to worry about.

Thanks so much for an answer. All the wait I have ahead is quite disturbing.
 John Kenyon, CNA - Thu Oct 02, 2008 10:37 pm

User avatar Hello -

First of all, there is no bundle branch block pattern, right or left, in the sample EKG you included here. Second, RBBB is not serious, often occurring in otherwise healthy, normal hearts. It may, in rare instances, be a precursor of a more serious type of block, but usually and of itself it has little to no significance. However, it's also not there, and if it were (or LBBB for that matter) it would show up in all leads, not just one or two.

On the other hand, your EKG is not textbook "normal", as it has some repolarization abnormalities as noted, with non-specific T-wave changes in III, avr and V-6. This could be due to a number of relatively benign factors or could even be a "normal abnormality" for you. Many of us do have fixed abnormalities that are non-specific, but are like a signature and are good to know about in case anything changes in the future.

T-wave inversion (what shows up in the three "abnormal" leads) can be caused by anything from hyperventilation to potassium depletion to positioning of the leads. It can, of course, also signify some non-specific heart disease, but in the absence of symptoms this is extremely difficult to know. A stress test would resolve any lingering questions about this. Deeply inverted T-waves are suggestive of ischemia or possibly an acute myocardial infarction. Flipped T-waves like those in the three questionable leads in your EKG, frequently mean nothing.

I don't think your symptoms match up with anything that shows up in your EKG. You may have hypervetilated during or prior to the test, or your electrolytes may have been off. The leads may have been improperly placed, or, and this is a stretch, you may have some old injury or ischemia, but it doesn't look like it. As you mentioned regarding "vague statements", a resting EKG won't always reveal occult heart disease -- only a stress test, with or without nuclear scan, and possibly a consequent angiogram, can determine this with any certainty. However, in the absence of classic symptoms, most doctors would consider this EKG mostly fine but with "nonspecific T-wave abnormalities" in III, avr and V-6. Not really much of a finding, but if it causes you a great deal of concern then you most certainly ought to follow up with the doctor about it. Again, although it would not be important anyway, there is no RBBB nor LBBB present in the EKG nor do the abnormalities resemble either of those patterns, so I'm perplexed by the doctor's notation in that regard.

Overall it is an unremarkable EKG, given the lack of symptoms.

I hope this is helpful. Please follow up with us as needed.
 d.soares - Mon Oct 06, 2008 5:53 pm

Thanks very much for answering.

It's very relieving to read this sort of thing, despite of feeling somewhat odd about the diverging interpretations about RBBB. For what I've been reading, I'd guess it were an "incomplete" one, but I don't really know much about it, I've just noted that the EKG does not fill all the requirements, starting with the length of the QRS, which strangely differs in the machine's diagnosis and the doctor's notes.

But my main worry was actually these inversions on the T waves, specially the one that does not match with the expected inversions if it were an RBBB, since I've read that the "good" inversions are typically asymmetrical, unlike these ones. But as you've explained, there's more to it.

I've finally scheduled a visit "in real life" with a cardiologist, and hopefully everything will be further clarified. According to what I've been reading, it could be a nasty-looking cluster of annoying things that are in fact harmless, "precordial catch syndrome", "da Costa's syndrome" and things like that. Some of them occur at clusters during one's lifetime, which is also good to know. Well, that's for the doctor to tell in the "real life" visit, but is a seemingly realistic perspective that helps me to sleep.

Thanks again.
 John Kenyon, CNA - Mon Oct 06, 2008 9:01 pm

User avatar Hi again -

You're very welcome.

While there is such a thing as "incomplete" RBBB, it doesn't really make much difference in the scheme of things. It's more difficult to recognize, and I don't see it, but it is somewhat open to interpretation and I've seen (and been in ) a few lively debates over things like this.

The T-wave inversions are odd, especially since they're not deep, so not especially scary looking. There are a lot of potential causes for this to happen, and you've listed some of them. They can be transient or they can, for some people, become the norm. It's good to know, in any case, so it can be compared with future tracings.

Thanks for following up and I hope you'll get back to us and share your "real time" experience with us. Best of luck with that, too.

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