So, my intended 60 miler on Saturday ended up only being a 40-something ride. 
After 30 miles I started to get palpitations in my chest, I stopped, started, stopped, started, stopped and ate some food, started again. Between 30-40 miles I must've stopped about a dozen times. I phoned the wife to pick me up once I'd crossed back over the Humber Bridge (didn't want her to be interrupted and have to pay to cross it twice!). She came out and insisted I call NHS Direct, who said it was probably nothing and they weren't concerened - but they still passed my details to my local GP Unit, who said I should go straight to A&E, but not to the GPU as there was a 3 hour wait. Like there wasn't just down the corridor in A&E.
Anyway, got seen and plugged up to a 12-lead ECG and left for a couple of hours. The doctor mentioned something about atrial fibrillation and an irregular heartbeat, turns out to be roughly the same thing and a potential clot building on a valve maybe causing it. Thank you Google. He wanted me to be admitted, I didn't, and after he'd discussed it with a specialist I got sent home and told to see my GP for a referral to cardiology. Also no strenuous exercise - so today's commute was the straight 5 miles rather than my usual 20-ish. (He also said no stress but for the whole 20 minute journey home I just received abuse after abuse from the wife about my diet!)
My GP wanted the letter A&E should've given me, but didn't. So now I have to wait for him to confirm it before I get the referral. Tick tock.
So my point in all this? Anybody here had it, causes, solutions? I know I can Google like the best of them but if anyone here has first-hand experience then I'll take that over any other.
Thanks in advance.

After 30 miles I started to get palpitations in my chest, I stopped, started, stopped, started, stopped and ate some food, started again. Between 30-40 miles I must've stopped about a dozen times. I phoned the wife to pick me up once I'd crossed back over the Humber Bridge (didn't want her to be interrupted and have to pay to cross it twice!). She came out and insisted I call NHS Direct, who said it was probably nothing and they weren't concerened - but they still passed my details to my local GP Unit, who said I should go straight to A&E, but not to the GPU as there was a 3 hour wait. Like there wasn't just down the corridor in A&E.
Anyway, got seen and plugged up to a 12-lead ECG and left for a couple of hours. The doctor mentioned something about atrial fibrillation and an irregular heartbeat, turns out to be roughly the same thing and a potential clot building on a valve maybe causing it. Thank you Google. He wanted me to be admitted, I didn't, and after he'd discussed it with a specialist I got sent home and told to see my GP for a referral to cardiology. Also no strenuous exercise - so today's commute was the straight 5 miles rather than my usual 20-ish. (He also said no stress but for the whole 20 minute journey home I just received abuse after abuse from the wife about my diet!)
My GP wanted the letter A&E should've given me, but didn't. So now I have to wait for him to confirm it before I get the referral. Tick tock.
So my point in all this? Anybody here had it, causes, solutions? I know I can Google like the best of them but if anyone here has first-hand experience then I'll take that over any other.
Thanks in advance.