A lot of us have been told by our doctors to cut out caffeine when we walk in the door with tach or ectopics. A lot of us report here that it doesn't help. Well, a study published this week shows an interesting trend in the data. People who drank more coffee had less arrhythmia related hospitalization. The control, those who drank decaffeinated coffee, did not show this correlation. This suggest that the mechanism of protection is the caffeine. A leading theory is that caffeine competes for adenosine receptors. This means caffeine is an adenosine antagonist. Adenosine's job is to make us feel tired and primarily works in the brain. This is why caffeine can keep you up.
Adenosine also affects the conduction system of the heart through receptors on your cardiomyocytes. This affects depolarization times and heart rate variability. Heart rate variability has big implication fo arrhythmias. HRV isn't the timing between QRS complexes or variability in your pulse rate. HRV relates to specific timing in the QRS complex itself. This means timing in the ST segment, or QT segment, etc. Changes in these timings can mean a lot, for example, prolonged QT interval can mean there's muscle damage. QT interval is the time from when the ventricles receive the AV trigger to beat to when they recover.
I think the study backs up a lot of the anecdotal evidence we see.
Here's the gotcha though. This is where epidemiologist need to be careful with studies. They show something called a "correlation" between caffeine intake and hospitalizations. This does not mean there's "causation". These are very different things and causation is difficult to prove. As an example, perhaps the reasons caffeine drinkers show less arrhythmia is because they are a population of people who aren't prone to it and thus drink more coffee. People who are prone to palps will cut the habit.
My advice, I still think caffeine does play a role in arrhythmia. This was a population study. Population studies are good at showing correlation but really bad at proving causation. A better study would be to actually observe the effects of caffeine on patients with arrhythmia to see what happens on EKGs.
If you're interested in the study please google the search terms "CCDEP coffee arrhythmia".
When I first started getting arrhythmia around 5 yrs back, my doctor told me to stop coffee. I did, but it seemed to make no difference to my palps. So I got back to 2 cups a day. I am now happy to read that more may be better !
I get my caffeine from chocolate, just love the stuff. I get on fine with decaf coffee, but do have one cup of black tea in the morning.
My wife got me off of regular coffee years before I became aware of my AFib. But, I would not conclude any relationship between the stopping regular coffee (an usually 4+ cups a day) and getting AFib. I in fact was later diagnosed with a leaky mitral valve which resulted in an enlarged left atrium... now there's a likely cause. I had the valve repaired a couple of years back... but continue to enjoy AFib. Heck, it it went away I might drift away from this "fun" Community.
As you point out, proving causation can be tricky. Actually, let me re-phrase that. It's not possible yet with the math we have to PROVE any sort of causation factor of a single variable in such a complex process. I didn't see the actual report, but rather an article about the findings, so I'm not quite sure, but when they say 18% less likely to be hospitalized, when the overall rate of hospitalization is 2.6%, we're talking about something like five less people per thousand, right?
And another thing that isn't clear here to me, is whether or not the coffee consumption was already being affected by the subjects' hearts. Meaning, maybe they hadn't yet been diagnosed, but people with arrhythmias were already cutting back on their coffee maybe because it made them feel fluttery or something. When they say that they don't find a similar result for tea, it also raises some questions about this caffeine/adenosine blocking affect. Basically, the study seems to say that if you've got an arrhythmia and can tolerate caffeine OK, then maybe you don't really need to cut it out after all. Maybe.
A question then: what about teas (not the herbal types) and energy drinks or sodas with boosted caffeine? Are those safe to drink for those with arrhythmias? I don't suppose those were included in the testing.
Geeze if i drank an energy drink i would be climbing the walls! I cut out caffienated coffee many years ago (roughly 8), i still got palps, then i cut out diet soda's that had caffiene in, i also still get them! BUT i will not cut out chocolate that only raises my heart rate a little, but i don;t get the skipped beats eating that!
I still weary about drinking caffiene again though, can be annoying going into a cafe and they do not have decaff! But i would raher drink water!
I have had atrial fibrillation for 10-12 years, have had 8-10 electro cardioversions and the only thing I can tell you about coffee is this: I can drink one cup of regular coffee and I will be in atrial fibrillation within thirty minuites... or can I drink anything with caffine in it such as Coke and the same will happen..If I eat very much chocolate it will make my heart irregular, if I eat lots of chocoate I will be in afib within a few minutes... as far as the study... I think it is wrong... like alot of studies... they can get the results they want depending on the way the study is conducted.... I think most of studies are worthless...sorta like political polls..they get the results they want... according to the way the poll is conducted and depending on who is conducting it. Claytex
I have to agree with claytex....up to a point. Now that I'm dealing with almost weekly episodes of a-fib, I feel like a real expert. In one way I feel like my a-fib builds...in other words, after an episode I feel deep in my heart the process almost immediately starts over again, literally deep in my heart. I could drink a margarita or glass of wine or a beer a day or two after an episode and it would not throw me into a-fib. I am drinking coffee almost daily. only a cup, and no a-fib. Chocolate-no a-fib. Herbal teas and and anything with ephedrine or pseudo-ephedrine-almost immediately. I don't do these things that trigger if I can help it. I don't care that much for coffee but I do know that the small amt I drink will not throw me into a-fib.
I'm really cynical about the study, that's why I wanted to bring it up for discussion.
I couldn't find out in their methodology how they normalized the data so that they didn't pick up misleading results. A few of us already eluded to the point that people who are drinking more coffee probably are not prone to arrhythmia. Those who drink decaffe are doing so for a reason and probably because they have disarrhythmia. So yea, it's not a stretch to predict these results.
It's like saying people who are out of shape tend to do poorly in marathons. Well yea, duh!
The study is very focused on just coffee. In the discussion they talk about effects of caffeine but there are many more sources of caffeine than just coffee. There's soft drinks, energy drinks, diet pills. None of these was included.
I suspect the study was sponsored by the coffee industry. This is a common practice, for instance, the red wine industry always sponsors studies on the health benefits of red wine and they don't even attempt to hide that fact.
Anyone thinking about going back to caffeine because of this study should think twice.
You know, there is caffeine in decaf too, only a much smaller amt. Also, I very rarely go to the hospital when I go into an episode of a-fib. I'm sure people new to the experience are not so lacidasical about it and therefore end up admitted to the hospital way more often than us old-timers. lol. The other thing I wanted to comment on that is a little off track is when I went for my last stress test they gave me adenosine and it immediately sent me into a-fib to be followed by a short run of v-tach. Sure scared me. I did have to stay in the hospital and they did serve me coffee for breakfast the next morning.
I'm amazed at the buzz this is generating among people with heart arrthymias. Don't most of us already know what our triggers are? I have experience with SVT, afib and PVC/PACS and I know that caffeine is a trigger for me no matter how many studies say otherwise.
Here is an exerpt from one of the better articles I have read about the study:
"So he and his colleagues analyzed data on 130,054 men and women who were treated at Kaiser. As part of a baseline medical check-up between 1978 and 1985, all participants completed a questionnaire that included information on coffee, alcohol, and tea consumption. Most were not asked to differentiate between caffeinated and decaffeinated coffee.
Through follow-up, 2.6 percent were hospitalized for an arrhythmia; half had a serious heart rhythm disturbance known as an atrial fibrillation.
When coffee drinking was evaluated as a continuous variable, increasing consumption was associated with decreasing risk of hospitalization.
In the small subset of 11,656 patients who provided specific information on their coffee consumption, it appeared the risk reduction was primarily attributed to caffeine, Klatsky said, although the small numbers precluded drawing firm conclusions.
While the observational design of the study meant that it could not establish a causal relationship, Klatsky said it was plausible that caffeine could be the protective agent involved."
WebMD had an article about this study which quoted a doctor as saying the researchers used hospital codes to determine which subjects had been hospitalized with an arrthymia and these codes were not always accurate. There is also the whole issue of being hospitalized. Does that include ER visits? Many people with afib go to the ER but are not hospitalized. What if those people were coffee drinkers? I had episodes of SVT for over 25 years before I ever sought medical care for it because my episodes were brief and not very symptomatic. I know that some of these episodes were triggered by caffeine, which is why I learned to use it very infrequently.
It does make you wonder why people would spend so much time and money researching the coffee issue. I should offer myself up as a cheap and easy study. Give me caffeine and watch my heart go into arrthymia.
And it should be noted that this study does not address the issue of the effect of caffeine on people who already have arrthymias. Just whether coffee may prevent someone from developing arrthymias in the first place.
Gee Marie, where have you been for the last 10 yrs, or do you just not post. "Most" of us do not "necessarily" know what all of our triggers are. I used to think caffeine was a culprit for me, but no, I can have a cup of coffee or glass of iced tea and no problem. If I have a glass of wine....bingo! I felt good about being able to drink coffee once again, well before this study was done. I think our triggers interact and any right combination can create the "perfect storm" for an event. New triggers can pop up anytime... just like the last discussion you posted on concerning the connection between v-tach and orgasms. :)
Excellent posts. I think the only thing that study proves is that a real scientific study is justified. Meanwhile, I'll stay off the coffee, and avoid the great smelling coffee aisle at my super market.
Exactly what i have been saying all along..hopefully they will do the 7 year cllinical study of the effects.....but who knows where we will all be when those results are in....people need to remember also that decaf coffee also has caffeine in it altho they say its only approx. 3%......good post you guys
great article, I'm going to google what you put in Itdood if my brain can take it all in today :)
I've not had 1 doctor tell me to cut out caffeine or foods, nor have any of them (8 or 10 so far) asked if I had any triggers, I heard about triggers on this forum first and tried to find my culprit, but other than stress or adrenaline nothing else affected my crazy amount of pvc's.
The thing I have noticed with studies is like someone else mentioned, they tend to "sway" a certain way depenedent upon who sponsors them - so if something bothers your or is a trigger, no matter what research says, I wouldn't do it :P
Dr. Rosenthal, a Cardiologist in NYC talked about this on FOX last Sunday. I''m so glad he did because whenever I have PVC's and drink coffee the PVC's got a lot better or even went away for awhile anyway. I could never understand that and my husband used to say that the "coffee calmed me down because I like coffee so much and that is why the PVC's got so much better". However, I just could not believe this and I used to tell him "but its caffeine how can that calm me down?" After listening to Dr. Rosenthal I now can make the connection.
Your doctors don't mention triggers because there's a huge gap between how doctors and patients perceive palpitations. Many patients find them torturing and debilitating, but most doctors think they're non life threatening and even trivial. If they're trivial, why are you given dangerous medicine, and how can they wreck your life?
I'm one of those who have these "dangerous" malignant pvc's - I've suffered VT and V-Fib episodes for awhile now and finally got a dx after surgery - I have long polymorphic runs of sustained & non sustained VT - no known cause after many tests & surgeries :)
I had 54,000+ pvc's daily for awhile and developed non ischemic cardiomyopathy, also dx with trace MVP, tricuspid regurgitation and some other things - NCS & OI along with ANS failure and peripheral neuropathy
grrr I hit post without the rest LOL - my brain needs to work right, but that's not happening anytime soon
my point was - even with an enormous amount of pvc's - 54,000+ pvc's no doctor told me to cut out coffee/caffeine and I found that strange, even after they knew what was wrong with me they still didn't tell me to cut it out knowing I drink coffee daily, caffeine isn't a trigger for me :)
hopefully they'll do some studies to get some concrete evidence on this since there are so many people who suffer pvc's - 1 or 100,000 pvc's are no fun to deal with, I've had my fair share and can empathize with anyone who has to deal with them, trivial or not :P
I agree with you. Thanks you for let that point so clear, I had my doubts with coffee and today I felt some palpitations and the only cause could have been the coffee.
And about the statistics I couldn't agree more with you.
My experience is the same as your claytex. I have to avoid everything with caffeine or any kind of "energy" producing ingredients or I am in a-fib within a couple of hours.
I learned this the hard way but I avoid stimulants like the plague!
thanks for validating my experience!
Coffee contains monoamine oxidase inhibitors such as harman and norharman. These inhibit the breakdown of dopamine and norepinephrine which are excitatory neurotransmitters. One would think this would increase the risk of an arrhythmia when used long term.
My mother, a heavy coffee drinker at the time, had PAT (paroxysmal atrial tachycardia) one night. Her heart was almost going 200bpm. The ER doctor told her to stop using caffeine. My heart also gives me palpitations when I drink more than a cup or if I drink it too quickly, so I drink it more slowly. Sometimes my heart will change rhythm and seem to "run away" for 10 to 15 seconds and scares the crap out of me. I've never had an abnormal ECG/EKG though, but the arrhythmia never occurred during the time the ECG/EKG was performed.
I've had a cardiologist tell me that caffeine is best avoided, especially if you're having arrhythmias.
I think that people with arrhythmias will avoid coffee. Heavy coffee drinkers most likely don't have any arrhythmias or if they do, it's not enough to end up in the ER.
I am careful about caffeine but I have not cut it out. I drink 2 or 3 cups of coffee a day and an occasional soda. I also eat chocolate but again I'm careful how much in a day.
The only time I have ever had problems though was when I ate way too many chocolate covered espresso beans. Not too clever.
I quit coffee 3 years ago in an attempt to reduce the frequency of SVT episodes. There was no apparent change in my condition, but I do think all else being equal it's better not to take something every day that alters your physiological condition, even if it's as benign as coffee.
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