Sometime stiffened ofvthe heart is a inherited disorder of the muscle or valves depending where the damage is located. It is known that some can be naturally treated while on the other hand some damage require a longer road to recovery. However the symptoms are similar but our genetic disposition determine how fast or slow we can recover.

Yes, Barbara is right. I did some googling and cardiomyopathy is what they call a stiff heart muscle that can't pump blood efficiently. The ventricles can't relax properly and Blood backs up in the vessels and the heart has to work harder. A stiff heart can come from inherited traits, or aging, high blood pressure, diabetes, or thyroid disease.
I'm sure there's more to it than these things, but I hope the info helps

Cardiomyopothy is one thing.

Thank you to Freda I really appreciate all of you guys words thank you

High Blood pressure. Age. Diabetes. All work with each other