@deniseheart "Cardioversion is a medical treatment that uses quick, low-energy shocks to restore a regular heart rhythm. It's used to treat some types of irregular heartbeats, called arrhythmias. An example is atrial fibrillation (AFib). Sometimes cardioversion is done using medicines.
Cardioversion is usually a scheduled appointment but is sometimes done as an emergency treatment. Usually, cardioversion quickly resets the heart rhythm.
Cardioversion is not the same as defibrillation. That's an emergency procedure that's done when the heart stops or quivers uselessly.

@deniseheart @laughlin1947
I completely agree with you AFIB can really affect the heart rate. I was told many times the ventricles will try to match the atrial.

I have an ICD/Pacemaker for over 20 years. I have been through so many shocks, issues, hospitalization it would take a page just to list them. I just got out of hospital where they were trying to find cause on VTAC.

I do know that my doctors were very attuned to my thyroid. I think @laughlin1947 should asked his doctors to test it as if high. Along with informing all medicines and supplements on. I have done this many times and just went through a visit with pharmacist who when over every medication and supplements I was taking. She had me come of so many supplements I had no idea they were affecting my medications. She also went over times to take and if with food, etc. I learn a lot form that visit which lasted one hour.

Many things can cause a high resting pulse rate and can be a trial and error journey to find the cause.