For years I have been trying to figure out what causes my rapid heart beats after eating sometimes. Three weeks ago I ended up being taken to hospital by ambulance with a heart rate of 150 bpm. I had eaten a cheese and tomato sandwich for lunch. I know for a fact the bread has no preservatives in it. I spent a few hours in ER but they were unable to tell me why this happened, heart rate went down and I went home. It has happened with various types of food, never the same thing. This has happened a lot over the years and answers I get from doctors is something like this - "If you eat a spicy meal it can increase your heart rate". That makes me feel like screaming 'Listen stupid I did not eat a spicy meal". The other symptom I get is increased ectopic beats. From now on I am going to keep a diary of food eaten and symptoms …

Three months later … I had two more trips to hospital with major irregular heartbeats, even the ambos were concerned. No joy from any of the docs as to what caused it all. I went to see my GP who I think has hit the nail on the head. He mentioned that coffee and chocolate could be responsible for causing both rapid and irregular beats. Chocolate seems to be my cause. He explained that it’s not just the caffeine in chocolate but the chemical that kills dogs if they eat chocolate. I told him that I had recently changed to dark chocolate because it was promoted as being heart healthy. He replied "that’s the worse of all". I did not think of chocolate because I would have no problems until 3 or 4 hours after eating it and I'm not talking about eating huge amounts, just 2 or 3 squares. I have since stayed away from anything chocolate and seem to be fine. My GP also told me that caffeine could raise blood pressure which in turn causes rapid heartbeats. If I do feel like a coffee I drink decaf. Not one person that I have told knew that chocolate could cause major irregular heartbeats. – Sally, by email

[Caffeine in coffee and theobromine in chocolate are natural food chemicals called methylxanthines. Dark chocolate contains about ten times more theobromine than milk chocolate. It is well known that chocolate can kill dogs but less well known that humans are also susceptible to chocolate poisoning if enough is consumed. The toxic dose for methylxanthines for dogs is about 150 mg per kilogram of body weight but as with other food chemicals, there is a wide variation in individual sensitivity. Symptoms of xanthine toxicity can include hyperactivity, irritability, nausea, vomiting, diarrhoea, and increased urination. These can progress to cardiac arrhythmias, epileptic seizures, internal bleeding, heart attacks, and eventually death. According to Wikipedia, the lethal dose for humans is approximately 10 kg. Food scientists warn that these food chemicals should be approached with caution by pregnant women: Eteng MU and others, Recent advances in caffeine and theobromine toxicities: a review. Plant Foods Hum Nutr. 1997;51(3):231-43. http://www.springerlink.com/content/r2j423713174l315/]