I recently bought a oximeter..I checked once while rest it was 95bpm 99spO2 and 7 PI% but after exercising a little bit I checked again and it was 130bpm 99spO3 and 2 PI%..I have a history of palpitations and panic attacks so my HR goes as high as 180 while exercising sometimes I had all tests few months ago and they came back normal the only thing that bothers me is why my PI% so low while higher bpms..can docs explain me this?thank you