Endurance Sports and Atrial Fibrillation – WHY?

Endurance Sports and Atrial Fibrillation – WHY?

starting a long run on the local PCT. We saw a bear that day – fun.

Exercise is supposed to be good for you, good for your heart, right? Then why is that endurance athletes have two to ten times the rate of developing atrial fibrillation compared to “normal” people? Is a little or moderate exercise good but excessive exercise bad? As an endurance athlete (marathons, trail running, long distance mountain and road biking) who has permanent atrial fibrillation (AF) I would certainly like to understand “WHY?”

There is a terrific article on Europace entitled Endurance Sport Practice as a Risk Factor for Atrial Fibrillation and Atrial Flutter . By internet standards it’s a long read but I will review it here.

The studies aren’t large, and male athletes predominate – but it is clear that endurance athletes have, as mentioned above – 2 to 10 times the likelihood of developing AF. It is not actually known why but it is thought that ectopic atrial beats, chronic inflammation, and larger atrial size are all risk factors.

Personally – the story checks out – I started having runs of “premature atrial contractions” years before ever going into AF, and because endurance athletes train more frequently and tend to avoid rest the atria are chronically inflamed, which leads to fibrosis (scarring) of the atrial muscle. And of course my left atrium has been severely enlarged for decades – not as much because of sports but because I had previously had mitral regurgitation (repaired surgically 1994 but the atrium never shrunk back to normal).

But even without the mitral valve issues endurance athletes tend to have enlarged atria. And we don’t rest enough leading to inflammation and scarring. The Europace article cites several studies that link long term endurance sports with AF, compared to sedentary individuals.

Moderate exercise may actually protect against AF.

Ringo after a long run – Fremont Trail

The Europace article also cites studies that show a correlation with “occupational physical activity” and AF – meaning people that have difficult, physically demanding jobs are also in the same boat as endurance athletes.

I didn’t know this – there is also a higher rate of AF related to how tall a person is – damn! I’m 6’3” (or 6’4” – depending on what year was measured.)

The article discusses, speculates, as to the mechanism of AF in the athlete’s heart but much of this is a bit technical for this blog. Feel free to explore the article if you are curious.

The typical clinical profile of sport-related AF or atrial flutter is a middle-aged man (in his forties or fifties) who has been involved in regular endurance sport practice since his youth (soccer, cycling, jogging, and swimming), and is still active. This physical activity is his favourite leisure time activity and he is psychologically very dependent on it. 

Interestingly the AF rarely occurs during running:

They almost never occur during exercise. This makes the patient reluctant to accept a relationship between the arrhythmia and sport practice, particularly since his physical condition is usually very good. The crises typically become more frequent and prolonged over the years and AF becomes persistent. Progression to permanent AF has been described by Hoogsteen et al .

Again, for me, the story checks out. I certainly recall long episodes of palpitations at rest that I now can identify as AF – until the day when it became (dreaded) permanent AF!

The article suggests that abstinence from sports is helpful for athletes having episodes of AF, although it isn’t curative. The problem, as any endureance athletes knows, is that it is nearly impossible to get us to give up our long runs, bike rides, etc.

Other therapeutic measures are also discussed – but that is a talk that is best left to the runner and the cardiologist.

Although ablation seems to be quite effective, endurance sport cessation associated with drug therapy seems to us a more suitable approach as an initial therapy, particularly in non-professional, veteran athletes.

To conclude I’m just going to quote their conclusions right here:

Vigorous physical activity, whether related to long-term endurance sport practice or to occupational activities, seems to increase the risk for recurrent AF. The underlying mechanisms remain to be elucidated, although structural atrial changes (dilatation and fibrosis) are probably present. There is a relationship between accumulated hours of practice and AF risk. Further studies are needed to clarify whether a threshold limit for the intensity and duration of physical activity may prevent AF, without limiting the cardiovascular benefits of exercise.

I’d be interested in others opinions and experiences with these issues. Reading this article was a little emotional for me – like I said – the story checks out! I guess that if I knew what I know now I might have cut down a little on the endurance sports before I was forced to do so by permanent AF. Truly, for me, a day long run with my dog, on a trail, in a local wilderness area was the most enjoyable thing I can imagine. And at this point it isn’t even the AF preventing me from still doing it – it’s the  high dose of beta blocker I take for rate control – really takes the wind out of my sails.



“C’mon Boss, let’s go for a trail run!”


Bariatric Surgery Lowers the Risk of Atrial Fibrillation

Bariatric Surgery Lowers the Risk of Atrial Fibrillation

I’m not sure how much this applies to endurance athletes, but I found this interesting. As, I think, everyday knows, obesity increases the risk of cardiovascular disease, and that includes atrial fibrillation. Researchers in Sweden recently published a study where they followed 4200 obese individuals with normal sinus rhythm (ie. not in a fib at the beginning of the study) for an average of nineteen years. During that period approximately half of the subjects had had bariatric surgery – basically various surgical procedures to rearrange the internal organs to force the patient to eat less and absorb less resulting in significant, life-changing weight loss.

The study found that 12.4% in the surgery/weight loss group experienced atrial fibrillation compared to 16.8% in the non-surgical/still obese group. That’s a 29% lower rate of developing atrial fibrillation for the surgery/weight loss group. Furthermore the study also concluded that, “Compared with usual care, weight loss through bariatric surgery reduced the risk of atrial fibrillation among persons being treated for severe obesity. The risk reduction was more apparent in younger people and in those with higher blood pressure.”

(Citation is HERE)

Other studies have shown that weight loss can be helpful in reversing atrial fibrillation and that ablation success rate is improved with weight control. I don’t have literature citations but I read this here.

So what does this have to do with endurance athletes with A fib? All endurance athletes are already thin, right? Well, obviously that isn’t true; but probably very few endurance athletes would meet the criteria for bariatric surgery. So we should be in the low risk group to begin with – so why do so many endurance athletes end up in a fib?

Well, as everybody knows distant runners and other endurance athletes often gain weight when they have to quit or reduce exercises because of, say, atrial fibrillation. These studies suggest better outcomes with weight control regardless of method.

As to why endurance athletes have a higher rate of A fib – I’ll address that in next weeks post.

Thanks for reading – please feel free to post comments below.

Quick Link: Wounded Heart Project


This isn’t an atrial fibrillation link, per se, but I think it will be of interest to readers of afibrunner.com. In Wounded Heart Project Shane describes his journey from having a myocardial infarction at age 42 (and subsequent obesity) to changing and regaining his health via improved diet (whole food plant based diet – yeah!) and exercise eventually becoming a sub-four hour marathoner even though his ejection fraction remains at 37%! That’s inspiring to me – is it inspiring to you?

Afib Runner News Update – Vitamin D Helps with Heart Failure & Exercise Helps Atrial Fibrillation Outcomes

brownmountaintrailBrown Mountain Trail

Vitamin D Helps with Heart Failure

I’m not certain this first item has much to do with readers of this blog – theoretically we are getting outside and getting plenty of sunshine, but a recent study showed that supplementation with high doses of vitamin D improved left ventricular structure and function in patients with chronic heart failure, although it doesn’t improve walking distance (citation below). I think the people in this study were a little worse off than a typical afib runner. In this study the non-placebo group received 4000 IU of vitamin D.

Personally, I like to supplement with vitamin D – one of two supplements that I take. I tested my vitamin D levels via a blood test several years ago and was at the low end of normal even with modest supplementation. This is interesting considering that I was running about 35 miles a week, all outdoors!

The other supplement I take is B complex – pretty standard for vegetarians.

Good news for fib runners: Exercise is good for your a trial fibrillation!

At the recent American College of Cardiology’s 65th Annual Scientific Session & Expo, findings were presented that show exercise reduces risk of cardiovascular death and all cause death. And it appears that the more you exercise the better the outcome.

I have a citation below, but I will summarize by saying that in a European study with over 2000 patients, subjects were divided into four groups based on weekly exercise: none (38.9%), occasional (34.7%), regular (21.7%), and intense (4.7%). In a two year follow up it was determined the “regular” and “intense” group had lower death rate, improved outcomes, etc. And of course the “intense” group did better than the “regular”, “regular” did better than “Occasional,” etc.

So there you go – justification for continuing to work out with atrial fibrillation. It seems obvious but it is nice to see proof.

Vitamin D and hearth failure:

Witte KK, Byrom R, Gierula J, et al. Effects of vitamin D on cardiac function in patients with chronic HF: the VINDICATE study [published online April 2016]. J Am Coll Cardiol. doi:10.1016/j.jacc.2016.03.508.

Exercise and afib:

Proietti M, Boriani G, Laroche C, et al. Physical activity and major adverse events in patients with atrial fibrillation: A report from the EURObservational research programme pilot survey on atrial fibrillation (EORP-AF) general registry. Paper presented at: 65th Annual Scientific Session & Expo; April 4, 2016; Chicago, IL. http://www.abstractsonline.com/pp8/#!/3874/presentation/42867.

Runners with Atrial Fibrillation – Considering the Watchman?

Are you considering the Watchman device?


Ever since having a TIA/stroke, I certainly have thought a lot about it.

What is it? The Watchman, by Boston Scientific is a little device, sort of like a basket, that can be inserted into the left atrial appendage, theoretically blocking it off and preventing clot formation. As you probably know already, clot formation may lead to Stroke. The device was FDA approved in the US in March, 2015, and has been used in Europe since 2005.

It’s placed in the left atrial appendage via a catheter through an artery in the groin, and if all goes well the patient can discontinue their blood thinner (warfarin, etc.) within six months.

Sounds great, doesn’t it?

I know I’d love to be protected from having another TIA or stroke and not have to take a blood thinner – I’m currently on warfarin + aspirin which makes bicycling, especially mountain biking, quite hazardous. But truthfully, it’s not that I necessarily want to be off the warfarin: I just don’t want to ever have another TIA/stroke. Recall that I had my event while I was already taking Pradaxa (and I never missed a dose). I just want a treatment that is going to work.


But there is some evidence to suggest the Watchman might not be as terrific as it sounds.

A recent study showed that the risk of a major bleed over the course of three years is the same with the Watchman compared to just staying on warfarin. Huh?

This is an excerpt from a Medscape article:

Patients with atrial fibrillation (AF) who received a left atrial appendage closure device (Watchman, Boston Scientific) or stayed on long-term warfarin therapy had similar rates of major bleeding during a mean follow-up of 3.1 years, in pooled analysis of two randomized clinical trials[1]. However, patients who received the device and were able to stop taking warfarin and clopidogrel at 6 months had lower rates of major bleeding from then onward, compared with patients receiving long-term warfarin.

Furthermore, in a very thoughtful, somewhat technical, article CMS Proposal on Watchman Is the Right Decision, Dr John Mandrola, a thought leader in Cardiology and Electrophysiology, agrees with the CMS proposal that “the evidence is sufficient to determine percutaneous left atrial appendage closure therapy using an implanted device is not reasonable and necessary.”


There are two major studies in the US regarding the Watchman. According to Dr Mandrola in the PREVAIL study, “Due to an excess of ischemic strokes, Watchman did not reach noninferiority in this category in the updated analysis presented to the FDA.” In PROTECT-AF study, “ischemic strokes were numerically higher in the Watchman group.” Which, ultimately, “leads one to conclude that the device is not effective.”

As for me, personally, as much as I’d like to believe the Watchman is a solution for me, the evidence, so far, is not convincing. I’m going to wait.

By the way, if any readers have experience with the Watchman PLEASE leave a comment below. We would love to hear from you!

Adverse effects of the Watchman:

“The main adverse events related to this procedure are pericardial effusion, incomplete LAA closure, dislodgement of the device, blood clot formation on the device requiring prolonged oral anticoagulation, and the general risks of catheter-based techniques (such as air embolism). The left atrium anatomy can also preclude use of the device in some patients.”

By the way – I linked a couple of articles from Medscape. I’m not certain but I think you need to be registered for that sight. Sorry.

Does Drinking Coffee Cause Atrial Fibrillation?


It has often been said that drinking coffee is related to developing atrial fibrillation. How about people who already have a history of atrial fibrillation? Can coffee trigger an episode?

A recent large study from Sweden shows that coffee consumption does not increase the chance of developing atrial fibrillation, even if quite a bit of coffee is consumed.

So coffee does not cause atrial fibrillation; not in people who have no history of atrial fibrillation.

But what about people who already have a history of atrial fibrillation? Can coffee trigger recurrence of atrial fibrillation?

The answer to that is probably yes, but more research needs to be done. In this study it was found that people who already had atrial fibrillation tended to drink less coffee than people without atrial fibrillation – probably to prevent triggering the arrhythmia.

As for me, I’m in permanent atrial fibrillation and it really doesn’t make much difference – I drink my normal amount of coffee and don’t worry about it.

Here are some excerpts from an article, by Colleen Mullarkey, in Consultant360:

After analyzing data from nearly 250,000 individuals, researchers found no association between coffee consumption and an increased risk of AF, according to the findings in BMC Medicine.

“This is the largest study to date on coffee consumption in relation to risk of atrial fibrillation,” says lead study author Susanna C. Larsson, PhD, associate professor in the Institute of Environmental Medicine at Karolinska Institutet in Stockholm, Sweden.

Larsson and her colleagues investigated the association between coffee consumption and incidence of AF in two prospective cohorts who had provided information on coffee consumption in 1997 and were followed up for 12 years—41,881 men in the Cohort of Swedish Men and 34,594 women in the Swedish Mammography Cohort.

Using the Swedish Hospital Discharge, they identified 4,311 and 2,730 incident AF cases in men and women, respectively, in the two cohorts. The median daily coffee consumption was 3 cups among both men and women.

In their analysis, the researchers found that coffee consumption was not associated with AF incidence, even in more extreme levels of coffee consumption.

They confirmed this lack of association in a follow-up meta-analysis that included both of these two cohorts along with four other prospective studies, which amounted to a total of 10,406 cases of AF diagnosed among 248,910 individuals.

“These findings indicate that coffee consumption does not cause atrial fibrillation,” Larsson says. “However, high coffee consumption may still trigger arrhythmia in patients who already have atrial fibrillation.”

While the researchers could not examine this possibility in the present study, they observed that participants who had AF at the time they completed the questionnaire about their coffee consumption drank, on average, less coffee (mean of 2 cups/day) than those who did not have atrial fibrillation (mean of 3 cups/day).

Data in the study suggests that some individuals who had AF at the start of the study may have quit drinking coffee or cut down their consumption because of an arrhythmic-triggering effect.

“Further study is needed to assess whether coffee consumption may trigger arrhythmia in patients with atrial fibrillation,” Larsson says.

Larsson SC, Drca N, Jensen-Urstad M, Wolk A. Coffee consumption is not associated with increased risk of atrial fibrillation: results from two prospective cohorts and a meta-analysis. BMC Med. 2015 Sep 23;13(1):207.

Now the next question: Does running really ruin your knees? (Ha ha)

Update Part 2 – Atrial Fibrillation, Pradaxa Fail, Transient Ischemic Episode, Blood Clot in Left Atrial Appendage

Jimi Hendrix sang, “manic depression’s a frustrating mess.” Well, I think the same can be said of atrial fibrillation!

mountainbikingwringoRingo and Me – Photo by Ben Vallejos

It’s been a while since I have written and I have to say the last couple of months have been nerve-wracking. As I posted in a previous entry I had a TIA (transient ischemic attack) while running a couple of months ago, had a normal carotid scan, but a TEE (trans-esophageal echocardiogram) showed that I had a small blood clot in my left atrial appendage.

In other words I had a “mini-stroke” and was at risk of having a full on stroke.


This TIA occurred while I was on Pradaxa, a newer, novel anticoagulant. At that point I was taken off Pradaxa, started on Lovenox (low molecular weight heparin) injections, and warfarin (Coumadin), and also aspirin. I was instructed to discontinue running, and bicycling, and limit my activity to easy walks, and a repeat TEE was scheduled two months after the initial one.

I won’t hold back any longer regarding the surprise ending – I never had a second TIA “mini-stroke” (that I know of) or stroke and the follow-up TEE (trans-esophageal echocardiogram) showed that the blood clot inside my heart is now gone. Hooray!

appendagePhoto – The little cul-de-sac is the LA appendage

Just to review how this happens: when you are in atrial fibrillation your atria is beating so fast it’s like it isn’t beating at all, just sort of vibrating. There is a part of the left atrium (the “appendage”) where the blow flow is extra sluggish, and this is where clots can form. When a tiny piece of clot breaks of and goes into the brain that’s a TIA. If a big clot is present and breaks of into the brain that’s a stroke, which of course can be disabling and even fatal.

It goes without saying that I am disappointed that this occurred while I was on Pradaxa. I figured that as long as I was taking it I was safe, and I liked not having to watch my diet or have blood tests constantly. Taking Pradaxa is easy – “set it and forget it.” Now I’m on warfarin (Coumadin), a royal pain in the butt, and have to micromanage my diet constantly – this drug is not an easy choice for a vegetarian! Eating too many greens (think kale) is dangerous as is not eating enough greens. Imagine trying to eat about the same amount of kale or broccoli or spinach each day.

zaPhoto – vegan pizza

My target INR is between 2.0 and 3.0, but seeing as I have had a TIA while on an anticoagulant I am trying to keep it nearer to 3.0 or even higher (3.0 – 3.5).

The two months between echocardiograms was an era of angst – anxiety and fear – for me, especially the first several weeks. Every symptom, no matter how minor, seemed like stroke. For example – lie in bed trying to get to sleep and your hand becomes numb – normal, right? Not when you know you have a blood clot in your heart – that seems like a stroke! Jump up from bed, start testing the muscle strength in each arm and leg, recite the alphabet, smile, frown, move eyebrows up and down checking for asymmetry. Do you think I’m exaggerating?

Every once in a while a person stammers or mispronounces a word. Normal? Maybe, but not when you are obsessed with a gigantic blood clot lodging in your brain.

As far as exercise was concerned at first I was limiting myself to short, easy walks more appropriate for a non-athlete. Eventually I became a bit bolder and started doing longer (but slow, especially up hills) hikes of an hour or two. It took me three weeks (!) to bridge to a therapeutic INR, so I was on warfarin and Lovenox for all that time. Once I was off the injections I started doing bike rides – but they were on non-technical trails and were slow, especially while going uphill.

My brain never got the memo that I was no longer a long distance runner/cyclist so I still ate like I was, and consequently I’ve gained some weight.

At this point, after finding out the clot is no longer present, I have started increasing the intensity of my bike rides, but mostly I’m still doing bike rides. I haven’t yet started running again – but I will.

I am mountain biking again, but not on any trails that would be considered challenging. Well, that’s not 100% true, I guess.

awol-1-2Photo – “Adventure Without Limits?”

As far as mountain biking is concerned I am phasing out technical trails (gradually). I made a deal with my self that if I didn’t have the blood clot on the second TEE I would get a new bike – and I did. I got a Specialized AWOL, which is a “gravel grinder.” That’s sort of a cross between cyclocross bike and a loaded touring road bike – basically a bike designed for gravel or dirt roads – we have an infinite supply of these around here so I have a lot of exploring ahead of me.

As far as that blood clot is concerned I’m very pleased it has gone away – but I am not fooling myself that it is gone forever. It could return at any time. It wasn’t there when I had my second TEE, but it could actually be there right now – how would I know? How long had it been there and how many times have I had a clot in that area? There’s no telling without doing a ridiculously expensive, somewhat invasive test over and over. I guess all I can do is stay vigilant, take my meds, watch the diet, and keep on trying to run, hike, and ride, even if it is at a reduced level.