@d050526
The dehydration can affect so many things including heart. You not only got dehydrated but then exercised for a long hard level time. Did you sweat during your ride. Drink liquids?

What is your normal resting heart rate? Your pulse was not overly high for doing the exercise you did and for as long as you did. And if dehydrated really could have affected it.

I just wore a 12 lead Holter monitor to see where my PVCs were coming from for a planned ablation on my LV.

I know every time I go to ER the very first thing is to check my electrolytes as has big influence on heart rate, and arrythmia. So not only staying hydrated but the taking in of electrolytes when you exercise and sweat. Most bottle waters (spring) contain electrolytes but you can look the up specifically to see exact amounts.