Here's a couple of slogans that I have found
6CO2 + 6H20 + sunlight = C6H12O6 + 6O2 + ATP
The heart rate would decrease because there is less oxygen being supplied to the cells for cellular respiration, and also your muscles won't get the blood it needs. Blood also contains oxygen and glucose which cells need to convert food to energy and to survive, so if the cells don't get blood they will die which will eventually kill the organism
