Avatar universal

RBBB - What does this history indicate?

I had 2 EKG's done today, and both seemed to show a right bundle branch block (RBBB). I'm wondering, however, if anyone can tell me what these numbers mean. I'm also including an EKG from 5 years ago which I was told was "normal".

***5 years ago***
Vent rate = 64bpm
RR Interval = 933ms
PR Interval = 154ms
QRS Duration = 108 ms
QT Interval = 380ms
QTc Interva = 387ms
QT Dispersion = 18ms
P-R-T axis = 27° 15° 6°


***Today, 8am***
Vent Rate = 64bpm
PR int = 163ms
QRS dur = 153ms
QT/QTc = 411/421
P-R-T axis = 45° 35° 9°

- 40+ MS S IN I / AVL / V5 / V6

***Today at 10:30am***
Vent Rate = 71bpm
P/PR = 128/156ms
QRS dur = 174ms
QT/QTc = 422/459
P-R-T axis = 51° 26° 12°

- QRS = 174MS
- RSR' in V1
- S > 30 MS IN I / V5 / V6

Note that my doctor (the primary, who performed the last test) noted a marked change between my V1 and V2 presentations between my previous EKG and my two current ones, stating that while the former presented a large spike downward then evening out:


the later presented a large spike that looks like a misshaped "M" followed by a "U"-ish "V"-ish looking thing.


(in the illustration, the second ^ was much lager than the first)

I guess I'd simply like to know if these numbers reveal more than what I've been told. I can see from this that it's an obvious RBBB, but do these numbers correlate with anything else? Particularly, do the differences between 5 years ago and today indicate anything?

- At time of first EKG I was 284 lbs. I went in due to perceived heart palpitations. (Was told these were normal in my case)
- Since then I lost 60 lbs, and was as low as 224 until 2 months ago. I am currently at 242. This rapid back and forth has been common in my life, despite my attempts otherwise.
- History of idiopathic gastroparesis
- history of anti-depressants and amphetamine use (Zoloft/Adderall). Used them for about 2 months, off them for about 2 months.
- History of anxiety disorder.
- I was really, really cold during the third exam listed. Shivering, in fact. Don't know if this affects results.

- 31 yr old
- male
- Hispanic (European descent)

I have an ECG scheduled for this coming week, then a consult with a cardiologist the week following. Are there any questions I should ask?

Thanks for any help.
Best Answer
1124887 tn?1313754891

I assume you know this is a community, not an "ask the doctor" forum. There are no doctors here.

EKG interpretation is not easy, especially for lay people like us. I'm a little "EKG nerd" myself, but I don't have any lisence for interpreting EKG's, and it would be wrong to try. I won't interpret your EKG's but I can explain some of the content.

First, RBBB (right bundle branch block) is a benign condition. We all have RBBB when we are born, but it disappears in most of us during childhood. A cardiologist told me that approx. 5% of us have RBBB (complete or incomplete) patterns in EKG as adults.

The way you describe it, this is obviously RBBB. It's also known as "rabbit ears" in V1.

What I don't understand, and what you can ask your cardiologist, is why the RBBB suddenly appeared. I can see your QRS duration is somewhat long in your first EKG, maybe this was an incomplete RBBB after all? I don't know. My QRS duration is a bit prolonged too, without any obvious reason (100-110 msec).

As I told you, RBBB is usually a benign condition, in contrast to LBBB, that is always caused by heart muscle damage. In RBBB, the electrical pathway to right ventricle is dysfunctional, so the signal must travel to LV first, then to RV, causing a prolonged QRS complex. This is visible in V1 as a spike after activating LV (because V1 "sees" RV, the negative deflection (down spike) is the activation of LV, with reversed current). The up-spike after the downspike is end-activation of RV after LV. The S in V5/V6 has the same reason, these leads "sees" LV, and you get a negative deflection from RV with reversed current.

The slightly prolonged QT is due to prolonged QRS in the setting of RBBB. To calculate QT, you remove the QRS time above 120 msec. In that case, your QT is fine.

The most important question is probably: Why did the RBBB occur? If you have a copy of the 5 year old EKG, bring it! It has great value.  

Rememeber: As this usually is a benign condition, there's no need to panic. RBBB is extremely common. It's good that you're seing a cardiologist just to get this out of your head.

Best wishes :)
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Avatar universal

I have rate dependent, intermittent LBBB, with no heart muscle damage.  I have had every test in the book, and an ablation for AVNRT.  I still, and will always have the LBBB.  Anyway, maybe intermittent doesn't require heart muscle damage?  I just hadn't heard that before, that all LBBB is caused by heart muscle damage.  Just curious.  My cardiologist and EP doctor have both said it is a benign condition, here hoping! lol

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Avatar universal
Thanks for taking the time to thoroughly answer. I realize this isn't a "doctor" community. (Once upon a time, I was quite active in the gastroenterology and GERD communities.) That said, there are usually a few people willing to give a responsible and thorough answer to an in depth question. Your reply did just that.

Although I am still quite concerned, I'm feeling somewhat better about this, or rather, any underlying conditions which may be causing this. The fact that there has been a marked change is what's really bothering me. As it so happens, I also have other previous EKGs from when I visited a cardiologist about 3 years ago at the Cleveland Clinic in Weston, FL. I didn't have those scans on hand, but I'll be sure to acquire the records before my next cardio appointment.  

Once again, thank you.
Helpful - 0
1124887 tn?1313754891
Hello both of you :)

Joshua: Rate dependent LBBB doesn't count. I'm talking about permanent LBBB, I don't know why RBBB is benign and LBBB is not, I guess none of them are problematic themselves, but LBBB usually has a cause. RBBB usually don't have a cause. Intermittent bundle branch blocks are usually right. Some people have both. I often get PACs with RBBB pattern, and they can be misinterpreted as PVCs. If they follow a LBBB pattern, doctors almost always misinterpret them as PVCs because PVCs usually occur in the RV; they are conducted to LV through slow pathways; showing a LBBB pattern. You can relax :)

It's good you're feeling better. I guess your cardiologist will provide most of the answers, but remember, though this condition looks scary on EKG, it's benign, and it doesn't indicate that your right ventricle will stop working or something like that. If the ventricles at some point get really unsynchronized, pacemaker therapy is available, but almost never used (because RBBB is a condition best forgotten that never gives symptoms). Yes, try to find your EKGs because the cardiologist will have the entire "history" of your heart. It's really valuable for him to see. I hope everything will be OK and that you can relax completely after you visit him!
Helpful - 0
88793 tn?1290227177
Don't say RBBB is benign.  Brugada Syndrome always inclusive a RBBB showed on EKG.  Of course, it has other like ST segment elevation in leads V1 to V3.  

I, myself also got RBBB which I have wpw at the young age of 15.

I don't know how to read EKG.  I'm not a doctor either.  I got the info from web.

Helpful - 0
1124887 tn?1313754891
Hi, I see your point, but in my opinion it's a little like saying "don't say sinus tachycardia is benign, because it occurs in heart failure". There are some non-benign causes to RBBB patterns, yes, but they are rare. Brugada (type 1 pattern) can look like RBBB due to the ST elevation, but I guess the EKG would be described more like ..IV\.. rather than ..^^u..  

I'm not a doctor either, we get the information mostly from the web (which I admit is a bad thing)..
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