What Causes Neck And Shoulder Stiffness Along With Muscle Spasms In The Chest?
I would explain as follows:
Welcome and thank you for asking on HCM!
Regarding your concern, I would explain that your symptoms do not seem to be related to any cardiac disorders.
A musculo-skeletal pain could be the cause underlying your complaints.
Anyway, I would recommend trying to correct your posture and use an orthopedic pillow.
A cervical spine MRI study would help exclude any possible bulging disc in this area.
Hope you will find this answer helpful!