Oh Bollocks

Apologies for the crude title but that just about sums up my feeling at the moment. This evening, I went out for my first ride since finishing L'Etape. I was really looking forward to a good old blast around the country lanes and seeing what effect all that hard work on Ventoux, followed by a week of recovery, had had on my legs. I was expecting big things! It was 5pm so fairly busy traffic and I was motoring along, feeling fine, really enjoying being out in the sun and easily keeping up with the traffic until I looked down and saw that my HR had gone way over my max of 169 and was currently around the 192 mark. There were some temporary lights with a big generator so I thought perhaps it was a bit of interference. I pulled over and took my pulse but couldn't manage to find it. I re-wet the HR monitor strap, made sure it was sat right and set off. I wanted to try to recreate the HR so I went for it, blasting along in the traffic and sure enough, the HR went quickly through the 140s, 150s, 160s and into 170s. Bugger. I was a bit worried now so I stopped and returned home. Colin was surprised to see me back again after only 10 minutes and when I explained that I thought my heart had gone again, he offered me his Polar watch and strap to do another test. This time I couldn't replicate the high HR and saw nothing over 155.
I have noticed that since the epic ride of last week, I have been waking in the morning feeling exceptionally groggy - kind of like that feeling one gets after nodding off in the afternoon and then sleeping just a little too long and waking up badly. I put it down to post Etape recovery. Now, after seeing those HRs, I'm wondering if I've gone back into flutter.
I will call the hospital first thing in the morning to make a check up appointment. I'm also going to start taking the aspirin again, just in case. There's little point thinking the worst but if the worst has happened, I know what I'm doing this time around.