Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Supraventricular tachycardia induced by chocolate – is chocolate too sweet for the heart?


Apparently chocolate, which is an adenosine antagonist, has the potential to cause arrhythmia.

Actually, the methylxanthines in chocolate are the adenosine antagonists (theobromine and caffeine), but it is the theobromine that appears to be what we (I) crave about chocolate. Should I give up chocolate or get an implanted defibrillator? While there is also caffeine in chocolate, only wimps get addicted to caffeine. That headache is just because people are more annoying without caffeine. The caffeine consumption is completely under control.

An otherwise healthy 53 year old woman consumed a lot of chocolate. The amount is stated to be a box, but we chocoholics do build up a tolerance.

Electrocardiogram showed supraventricular tachycardia at 165 beats per minute, which was restored to sinus rhythm after adenosine bolus injection.[1]


6 mg?

6 mg followed by 12 mg?

6 mg followed by 12 mg followed by another 12 mg?

We don’t know.

Image credit.
And throw in a six pack of adenosine,
A man’s got to know his limitations.


My inner woman has an old soul, so we gots to know – are we endangered by the chocolate I am currently consuming in supratherapeutic quantities?

While it may be easy to have too many medics, it is blasphemy to suggest that one can have too much chocolate.

Electrophysiology studies showed atrioventricular nodal reentry tachycardia, which was treated with radiofrequency ablation.[1]

A conduction abnormality that was previously undetected? And it is blamed on just a few dozen pounds of chocolate?

The family stated a box of chocolate, which they considered to be a lot, but the family may be unenlightened, when it comes to chocolate.

There are occasional case reports describing association between chocolate, caffeine, and arrhythmias. A large Danish study, however, did not find any association between amount of daily caffeine consumption and risk of arrhythmia[1]

Clearly this is propaganda paid for by Big Caffeine!

Vitals were temp, 98.0; pulse, 150 beats per minute; blood pressure was 87/57 mm Hg; respiratory rate, 25 breaths per minute. Electrocardiogram showed paroxysmal SVT at 165 beats per minute (Fig. 1).[1]

Click on images to make them larger.

Patient was later transferred to the cardiac electrophysiology laboratory of New York Methodist Hospital. Protocols included decremental pacing and programmed stimulation; AV nodal reenterant tachycardia was easily induced and reproducible.[1]

I suspect that the rhythm was induced without chocolate. While the chocolate may have been a contributing factor, this does appear to be an interesting possibility, rather than a effect that has been demonstrated.

I may be more likely to have palpitations when anticipating chocolate, than after consuming that nectar. After all, I’m just trying to get well.

The authors also mention that research suggests that moderate amounts of chocolate (not enough chocolate) can be good for the heart.

A recent study published in the European Heart Journal showed that chocolate
consumption of about 7.5 g/d was associated with a 3.9% lower risk of myocardial infarction and stroke [1]. The risk reduction was attributed, in part, to lowering of blood pressure. Much of the benefits are attributed to flavonoids in chocolate with release of nitric oxide, lower blood pressure, and improvement in platelet function.


Hello dark chocolate, my old friend.


[1] Supraventricular tachycardia induced by chocolate: is chocolate too sweet for the heart?
Parasramka S, Dufresne A.
Am J Emerg Med. 2012 Sep;30(7):1325.e5-7. Epub 2011 Aug 25. No abstract available.
PMID: 21871761 [PubMed – in process]

Parasramka S, & Dufresne A (2012). Supraventricular tachycardia induced by chocolate: is chocolate too sweet for the heart? The American journal of emergency medicine, 30 (7), 132500000-7 PMID: 21871761



  1. You’re playful today, Mr. Noonan!

  2. I suspect that the rhythm was induced without chocolate. While the chocolate may have been a contributing factor, this does appear to be an interesting possibility, rather than a effect that has been demonstrated.

    So, adenosine isn’t diagnostic for SVT; but chocolate might help diagnose a previously unknown conduction abnormality? When do ambulances and EDs start stocking chocolate (for diagnostic purposes of course)?

    Love the Clint references too!

  3. Love this. I am resting easy knowing my heart is safe, regardless of how much chocolate I consume.

    Now….where did I put my bag of Dove chocolates?…..

  4. I belive that chocolate causes PVCs. I have a possible genetic arrhythmia problem. I was diagnosed large 1st degree AV Block and had TdP event in 2000 in my 30s. I had a likely similar event in 1993 and a smaller one 1981. Neihter of these events were associated with chocolate consumption. I now have an AICD with only one SVT event tracked- probably while running.

    However, consuming even 0.5 to 1.0 ounce (15 to 30 grams) has caused me to experience PVCs while not active. This happens more often on an empty stomach. I am trained as an MS-level statistican. I have no doubt about the causal relationship between chocolate consumption and PVCs, at least for me.

    • I agree with Jeff, unfortunately. I love chocolate. My situation has been complicated as it is not ALWAYS the same result when I eat chocolate. I had the idea that a combination of foods (and events) might be the key. I cannot eat chocolate in the late afternoon/evening (even a little,even milk choc) or I’ll have PVCs all night and possibly tachycardia that will wake me up suddenly at 165-180bpm (this resolves from a few seconds to hours). I have found that even milk chocolate causes a problem. Again, I think there are relations between things. Eating anything spicy with chocolate will give me tachycardia every occasion at night. It could be GERD as well. I hear that chocolate causes problems with the esophogeal sphincter muscle? Thank god its not all sphincters! I recently had a Starbucks hot chocolate before I took a flight (about 3 hrs) and had a mild episode of tachy upon take off. Could have been chocolate + anxiety. The Tachy episodes are not typical anxiety attacks. Also, Type 2 diabetes and mildly abnormal sugar levels effect this, with the chocolate, and not just because of the sugar.

  5. Coffee and chocolate in any amount no matter how small trigger my svt’s