"Frustrated by doctor at Princess Royal University Hospital"

I attended the PRUH A&E due to very severe irregular heart beat only to be informed by an  A & E doctor that given the "medical fact" that long term caffeine use decreases brain function (as oppose to its short term stimulant effect), it must follow logically that long term use should also cause a slowing of the heart rate.

Caffeine's primary mechanism of action is as an antagonist of adenosine receptors i.e. it blocks or dampens agonist-mediated responses rather than provoking a biological response itself. Adenosine is medically used to slow the heart rate and by blocking the action of adenosine result in heart rate increase. As a result it pharmacological action is no different than that of a beta blocker. If one follows this medical logic, then it should follow that long term use of beta blocker will enhance epinephrine action and will cause hypertension rather than treat it. Yeah, whatever!

I feel this doctor was arrogant and didn't listen. The outcome for me was that I didn't believe a word this doctor told me, I felt he made it up as he went. I feel better off consulting with Dr Google.