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Suffering with RBBB, scheduled for MRI. Does RBBB get worse without there being an underlying issue?

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I have a RBBB, it had a QRS of 106ms in 2006, it was 114ms in 2010, now it is 142ms. I swim 2 miles per day and am otherwise not symptomatic. My cardiologist is scheduling an MRI. Do RBBB get worse without there being an underlying issue. I had an MRI for the same reason in 2010 and my doctors said it was benign. Thanks
Posted Mon, 20 May 2013 in Hypertension and Heart Disease
Answered by Dr. Jorge Brenes-Salazar 3 hours later

Thank you for sharing your health concerns.

By the duration of the QRS complex in 2006 and 2010, you had incomplete RBBB (QRS less than 120 ms), and now it is complete RBBB. Indeed, over time you can see progression from RBBB pattern to RBBB block like in your case, particularly if you have had hypertension for a while, but in the vast majority of cases, it does not confer an increased morbidity (medical complications) or mortality risks; a very different story is that of left bundle branch blocks, which actually have been linked to worse outcomes.

I hope that findings on cardiac MRI are benign. Wish you the best health,

Dr Brenes-Salazar MD
Cardiovascular Diseases
Mayo Clinic Rochester
Above answer was peer-reviewed by
Follow-up: Suffering with RBBB, scheduled for MRI. Does RBBB get worse without there being an underlying issue? 3 hours later
Thank you for your follow-up. The first time I became aware of my IRBBB was in 2010. I then had an MRI and my Cardiologist called me and said my condition was benign and that I had nothing to worry about. Now 2 1/2 years later it has gone from IRBBB to RBBB. Just for perspective, I began swimming 18 months ago, for 70 to 90 minutes at a time, 5 days per week. Sometimes I swim hard. I used to run more because exercise has always been important to me. I have never had hypertension, I am not overweight and candidly I have never felt better. That is all good. What worries me is my father, an MD, died of heart disease at age 37. I quit smoking 31 years ago at age 20. (started after he died) and though I have always been pretty conscientious about my diet; my total cholesterol has always been around 200 with HDL around 45. I also had pulminary Sarcodosis in the early 90's that spontaneously resolved in 1992. Coincidently, I was seen at the Mayo Clinic at that time by a doctor Rosen in the pulminary department. Therefore, this could go ether way in my opinion even though my local physicians have tried to be optimistic. As I review this in my mind, the biggest negative is how the QRS complex has progressed. The positives I most cling to are a. I just had an MRI, 2 1/2 years ago, focusing on the same possibilities, and it was negative for any disease process, including Sarcoidosis involvement and b. I look and feel really good and I tolerate exercise very well. Is is possible that something could have changed that much negatively in terms of my cardiovascular health in just 2 1/2 years? Could my swimming have enlarged my heart and thereby exasperated my RBBB? Is it possible that the MRI missed something 2 1/2 years ago. Is the QRS progression I described unusual? I am worried; yet I feel so healthily that, in a way, the whole thing does not make sense. I think I also just wanted to vent about this to someone. PS if I am interested in getting a second opinion, does the Mayo Clinic in Rochester do comprehensive cardiovascular evaluations that may be even more thorough and detailed than what I am receiving. I really worried about this two years ago and then when I was told the condition was benign I simply moved on. I want to get the to bottom of this consideration once and for all now. Thank you for listening.
Answered by Dr. Jorge Brenes-Salazar 17 minutes later

Thanks for the detailed history.

With a history of sarcoidosis, in retrospective it was reasonable to obtain an MRI to rule out myocardial involvement, although its rare and would present clinically either with heart failure or advanced conduction disease.

As we age, there is some degree of fibrosis of the conduction system; looking at the hard facts I would not be overwhelmed by this benign finding as long as it does not progress, meaning additional conduction disease such as first degree av block, fascicular block or others. Your exertional capacity is reassuring. I believe that if an MRI is obtained now, it would be useful to look specifically for any structural changes since 2010. I believe that still we are dealing with a benign EKG finding.

Hope this is helpful. Wish you the best health,

Dr Brenes Salazar
Above answer was peer-reviewed by
Follow-up: Suffering with RBBB, scheduled for MRI. Does RBBB get worse without there being an underlying issue? 4 hours later
Just a few more questions, my second to last pulmonary function test was just outside of the COPD range. This was in 2010 and my FVC was 81% and my FEV1 ratio was 73%. I had another pulmonary function test 10 days ago, during the same physical exam that showed my IRBBB was now a RBBB. The person administering the test indicted that I did better than in 2010; yet not as well as in 2008 when my FVC was 97% and my FEV1 ratio was 68%. As I have mentioned, I have always ran, cycled, or swam; yet if anyone had ever asked, I would have said my lungs are the weakest link. I started smoking cigarettes at an early age. I had a terrible cough by my junior year in college so I quit. Then 10 years, or so later I had the bout with pulmonary sarcoidosis. My question is this, I do not technically qualify for mild COPD based on the numbers; yet I am close. I believe my exercise has made my lungs very efficient; yet I wonder, now that I am swimming, breathing every third stroke, inhaling and exhaling quickly at times, could this put pressure on my right bundle branch area in anyway? I used to hold my breath when my head was submerged, then I read that was not good for the lungs. I should tell you that I taught myself to swim laps, so I initially had the wrong breathing technique. I realize this may be a foolish question; yet just from your perspective could holding my breath and swimming hard between strokes and/or even now with the right breathing technique put an XXXXXXX pressure on my right bundle, if air that I am exhaling is slightly obstructed? Perhaps a pulminologist you know might have an opinion as well. Thank you PS I do not have a lot of mucus etc., that is a characteristic of COPD; yet I do have a slight and occasional dry cough.
Answered by Dr. Jorge Brenes-Salazar 6 hours later
Thanks for the follow up queries. The diagnosis of COPD is a clinical one, defined by chronic cough with sputum production at least for 3 cumulative months a year for 2 years (bronchitis) or by an abnormal gas exchange (decreased DLCO) with evidence of centroacinar alveolar destruction by imaging (emphysema). The ratio falls into the obstructive category, but as you mention the FEV1 is within normal limits. If you don't have any of the aforementioned definitions, I would not worry too much about it now.

In terms of your other question, it would be unusual for those periods of breath holding to cause increased right sided pressures and therefore have an impact on your conduction system; your lungs have probably adapted to extract a higher amount of oxygen during those conditioning. If you continue concerned about your exertional capacity, probably the most informative test would be a cardiopulmonary exercise oxygen consumption; our lab here is top quality in those.

Hope this information helps.

Wish you the best help,

Dr Brenes-Salazar MD
Above answer was peer-reviewed by
Follow-up: Suffering with RBBB, scheduled for MRI. Does RBBB get worse without there being an underlying issue? 3 hours later
I am still waiting for the MRI to be scheduled, my appointment with the Cardiologist was just last Friday. I feel optimistic about the overall situation; yet I did just read the results of a recent Copenhagen study that indicated persons with RBBB that had no indication of underlying cardiovascular disease had a 30% greater likelihood of death from all causes that the general population. Primarily from cardiovascular issues. Both of my physicians have indicated that they consider RBBB benign in absence of indications of heart disease. What do you think of the Copenhagen study? Are you aware of any studies that have reached different conclusions? What are some benign reasons that might explain why my IRBBB went from a 106ms RHS in 2006 to a 142ms RBBB 10 days ago. Is that type of increase unusual? Finally, is it possible for RBBB to reverse and to become less severe in RHS duration. I have already made some lifestyle changes I believe may help. Thank you for all your time and advise.
Answered by Dr. Jorge Brenes-Salazar 2 hours later

This is the best position paper to reply to the findings of the Copenhagen Study:
Eur Heart J. 2013 Jan;34(2):86-8. doi: 10.1093/eurheartj/ehs359. Epub 2012 Nov 7.
Right bundle branch block: are we looking in the right direction?
Fernández-Lozano I, Brugada J.

Of course, it is an even more valid opinion than mine (Dr Brugada). The highlights:

1) The study is observational, then because of this you can't establish a cause-effect relationship, thus are we seeing the increased CV risk DUE TO THE RBBB (I don't think so) or the many conditions that it is associated with (increasing age, HTN, ischemia, heart failure, cor pulmonale)

2) Our current practice guidelines would still not do any more testing or device implantation in your case based on the fact that we have had no evidence that you have neither heart failure nor ischemic heart disease; at the end of the day, you still qualify as asymptomatic RBBB

3) I believe that perhaps just "aging" might generate those changes over the aforementioned time frame; of note, we also see not infrequently RBBB in athletes. In my experience, it is quite rare to see "a decrease" in the RBBB

Hope that helps. See if you can access that article, I highly recommend it.

Dr Brenes-Salazar MD
Above answer was peer-reviewed by
Follow-up: Suffering with RBBB, scheduled for MRI. Does RBBB get worse without there being an underlying issue? 4 hours later
Doctor Brenes-Salazar, you have been a big help. I have never used an online service like this for any reason. I feel fortunate to have had you as a resource. I will find and read that article. Finally, I have been athletically involved my whole life; not an elite athlete, just a good one. Do you believe my swimming regiment of 70 to 90 minutes at a time, roughly 1 1/2 to 2 miles a day beginning 18 months ago qualifys as "athletic" in terms of the people you have seen with RBBB in your experience? Before that I ran roughly 40 to 60 minutes 5 days per week since college really, or when I cycled we would go for roughly 2 hours. Years ago, a client of mine, ironically a cardiologist, gave me a treadmill stress test after I requested that he do so. I was in my 30's. Besides saying the results were normal, he said "you do have a slightly enlarged heart; we see that sometimes with athletes." He is retired now, so I have not discussed this with him yet. Thank you again, I wish you happiness and success.
Answered by Dr. Jorge Brenes-Salazar 29 minutes later

It is my pleasure to assist you. Indeed, your level of physical activity is truly athletic, and that might well be the etiology of the rbbb. as you read from the Copenhagen study, progression from Rbbb to more advanced forms of heart block is not frequent and very importantly, prognosis is likely related to the underlying etiology (eg. compare the outcomes of someone with diffuse coronary artery disease vs an athlete or just an elderly healthy person, they all can have a rbbb but their risk for events us quite different)

All in all, I encourage you to continue your healthy lifestyle practices; they are the most important prescription we can give as cardiologists

Wish you the best health,

Dr Brenes-Salazar
Above answer was peer-reviewed by
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