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.

Watchman Device Update

A little one a year ago I wrote about the Watchman device. People with atrial fibrillation often develop a blood clot in the part of the left atrium called the left atrial appendage. This Watchman device basically closes off this area to prevent clot formation.

Last time I wrote the device was relatively new (long term data wasn’t yet available), and based on my research it didn’t seem like a great choice. I would refer you to this excellent article on John Mandrola, MD’s blog: Say No to Watchman.

As a person who has already had a ministroke and a verified blood clot in my left atrial appendage, well yes, I am very interested in a device that would prevent me from having a stroke which, at this point, for me, seems pretty much inevitable. Technology improves over time, right?

So what is going on with the Watchman now?

Well, Boston Scientific released its final five year outcome data from the PREVAIL study, along with five year outcome data from the PROTECT-AF trial. I would refer you to an excellent article in Cardiac Rhythm News (link).

At first look I was fairly optimistic:

In the PREVAIL and PROTECT-AF randomized clinical trials, LAAC with the WATCHMAN device was compared to warfarin for stroke prevention in high-risk patients with non-valvular AF. In addition to stroke prevention comparable to warfarin, the analysis concluded the WATCHMAN device also effectively reduced non-procedure related major bleeding, disabling or fatal stroke, and mortality.

Source Cardiac Rhythm News

I had been thinking the best course of action would be to, perhaps, have a Watchman implant and just remain anti coagulated. After researching this, however, that doesn’t seem like a good plan. The Watchman device has been shown to protect from strokes with an outcome similar to warfarin; but it turns out most of the additional benefit of the Watchman is basically related to the fact that those patients didn’t suffer as many warfarin related side effects/deaths from strokes caused by bleeding or from other major bleeds:

The analysis confirmed a 55% reduction in disabling or fatal stroke, largely driven by an 80% statistically significant reduction in hemorrhagic stroke. Further, the combined data demonstrated a 52% decrease in non-procedure related major bleeding and 27% reduction in all-cause mortality when compared to long-term warfarin therapy

Source Cardiac Rhythm News

At best, regrettably, the Watchman device might be equivalent to warfarin as far as stroke prevention is concerned, but not necessarily better. At best, I think, it would be a good choice for people who have had problems (such as bleeding) with warfarin; but it hasn’t been tested on people who are not eligible for anticoagulation (who are generally less healthy patients). And the Watchman hasn’t been tested against the newer anticoagulants (Pradaxa, Eliquis, Xarelto) which may actually be more effective than warfarin.

So I’m just going to keep watching and hoping for a better option than the Watchman device. I’d be interested in your opinions, and especially in the opinions of anybody reading this who has had a Watchman implant. Please comment below.

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.

Warfarin Withdrawal in Patient’s Awaiting Surgery Increases the Risk for Stroke


Last April Dr. Adnan I. Qureshi reported on research, at the 67th Annual Meeting of the American Academy of Neurology, that has shown that atrial fibrillation patient’s who are taken off of warfarin for surgical procedures have an increased likelihood of having a stroke.

Subjects included in the analysis had atrial fibrillation plus at least one additional risk factor for stroke or death: age >65 years, systemic hypertension, diabetes, congestive heart failure, transient ischemic attack, prior stroke, left atrium diameter 50+ mm, left ventricular fractional shortening <25%, or left ventricular ejection fraction <40%.

Specifically atrial fibrillation patients who discontinued warfarin for surgical procedures had a 1.1% rate of stroke while atrial fibrillation patients who remained on warfarin had a 0.2% rate of stroke.

Read more here:

Warfarin withdrawal in atrial fibrillation patients awaiting surgery dramatically ups stroke risk

Well, this seems like one of those articles where you read the headline and think, “Duh!” Like the article about how obese children have a higher chance of hypertension – No kidding?

Obviously if you are on a medication, in this case warfarin, to prevent having a stroke, and you stop taking the medication, well, you have an increase likelihood of having a stroke. I think everybody suspected this – but what we see here is that the rate of stroke increases five-fold. Wow – that seems incredible!

This article reinforces my strong belief that strict compliance with taking my medications, especially warfarin, is a good idea!

As far as surgery is concerned, clearly, if you need to have the surgery and you need to go off the warfarin, then so be it. The article didn’t mention anything about bridging with Lovenox. You might want to ask your surgeon about that. And also – consider how important the surgery is to your general health. Is the surgery truly necessary? Is it worth risking a stroke?

La Muerte Tocando Guitarra

Runners with Atrial Fibrillation – Thinking About Having a Cardioversion? “Look Before You Shock”


This is, so far, the most discouraging article about atrial fibrillation I have ever read:

Left Atrial Appendage Thrombus When Least Expected: Look Before You Shock, Evaluate Before You Ablate | EP Lab Digest

As a distance runner with atrial fibrillation, who never missed a single dose of my anti-coagulant, and who has already had a blood clot in my left atrial appendage, and has already had a “mini-stroke” – this one leaves me feeling a bit hopeless.

Feel free to read the article; but I will go over a few key points here. One of the dreaded consequences of atrial fibrillation is having a stroke. Because the top chambers of the heart, the atria (plural of atrium) are beating so fast that they are basically just sitting there vibrating, the blood pools and becomes sluggish, and is prone to forming blood clots. Combine this with an enlarged left atrium and the likelihood is even higher. The blood clot forms in a little corner of the heart called the “left atrial appendage” (LAA).


That’s where I formed a clot. If the blood clot, or a piece of the clot, breaks off it can quickly travel to the brain, get caught and cut off the circulation to part of the brain. This is a type of stroke, and is a huge problem for people with atrial fibrillation.

There are people who like to refer to a stroke as a “brain attack” because that’s what it is – like a heart attack in the brain. And like heart attacks there are big ones and small ones. I had a small one (TIA – tangent ischemia episode) that fortunately only lasted a minute or so. A big stroke, of course, can be fatal.

Important point: if a person is in atrial fibrillation and has blood clot in the LAA, it might be very stable. It might be just sitting there, hanging out, because the atria isn’t doing any beating. Everything is pretty tranquil in there. But then the person has a cardioversion (shock to reset the beating heart) or an ablation and the atrium begins to beat again, the blood starts moving through more quickly – well – now there’s a problem. Now the clot can break loose and BLAM!! – you’ve had a stroke!

The problem: it’s difficult to tell whether or not a patient has a clot prior to having a procedure. A regular echocardiogram doesn’t even show a small clot; there’s not enough detail. The best way to determine if a clot is present is to do a transesophageal echocardiogram (TEE).

teeTransesophageal Echocardiogram

I’ve had three TEEs – it’s not fun – sort of like swallowing a telephone. Thankfully the last two that I had involved an anesthesiologist who put me to sleep for the procedure.

As far as I know it is fairly common to have a TEE prior to having an ablation procedure; but less common before a cardioversion (the shock!), especially for people who presumably have a low risk of a LAA blot clot – like people who are appropriately anti-coagulated, or people who have had atrial fibrillation for less that 48 hours.

In this article five interesting cases are reviewed.

Case #1 – a patient who was effectively anti-coagulated but turned out to have a LAA clot anyway (sounds familiar).

Case #2 – a patient who was actually more anti-coagulated than thought necessary, and was in atrial flutter for less than 48 hours, but turned out to have a LAA clot anyway.

Case #3 – an appropriately anti-coagulated person with a low risk of clot (CHADS2 score=1), but turned out to have a LAA clot anyway.

Cases #4 and #5 were high risk patients who would be expected to have a high risk of a clot. Case #5 actually had three clots in her heart – yikes!

How does all this apply to athletes with atrial fibrillation? Well, apparently healthy, athletic patients, who are appropriately anti-coagulated, and either undergoing a planned or emergency cardioversion, still have a certain risk of having a LAA clot and subsequent stroke.

Should everybody have a TEE before having a cardioversion? Probably not. TEE is expensive, unpleasant, and if anesthesia is involved it basically takes up an entire day out of your schedule. It might be a good idea to talk it over with your cardiologist, however.

Happy Trails