A resting heart rate of 145 should be addressed with your cardiologist. I wouldn't do anything strenuous until you talk to him. Walking is good exercise and shouldn't overtax your heart. I don't know what TVR means so your doctor is the best person to get you on the right track. Sending hugs and prayers.

I signed up for cardiac rehab with the doctor's office I got to go tomorrow and do the paperwork hopefully they'll figure it out

I thought about joining a gym but then who's going to watch me make sure I'm not overdoing it for at least a couple weeks

Call your doctor, that is too fast you might be in an arrhythmia. Keep us posted on what the doctor tells you. Hugs🤗

Kinda fast check with your Dr