What Causes Backache And Left-arm Ache Despite Normal ECG And ECHO Results?
I would recommend 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.
Your performed cardiac tests which have resulted normal, and this is very reassuring.
Anyway, an exercise cardiac stress test would help definitely exclude any possible coronary artery disease (although it would be really exceptional at your age).
I would like to know if the upper back discomfort and in the left arm is modulated by body movement or physical activity. This fact would indicate a musculo-skeletal pain as the main cause of your complaints.
I would also recommend performing a cervico-thoracic spine X ray study to investigate for any possible bulging disc in the vertebral column, which can lead to irradiating radicular nerve pain in this region.
You should discuss with your doctor on the above issues.