Thanks for your question on HCM.
I can understand your situation and problem.
Your
chest discomfort is on left sided with arm weakness, so we need to rule out cardiac cause first.
So get done ECG first to rule out cardiac cause.
If ECG is normal than no need to worry much for cardiac cause.
Chest pain on inhalation is also seen in pleurisy (inflammation of pleura). So get done chest x ray to rule out possible causes of pleurisy like pneumonia,
pleural effusion,
tuberculosis etc.
If chest x ray is also normal, I think it is
musculoskeletal pain mostly due to muscle pull.
So try to follow these for better symptomatic relief.
1. Avoid strenuous exercise and heavyweight lifting.
2. Avoid movements causing pain.
3. Avoid bad postures in sleep.
4. Take good painkiller and
muscle relaxant.
5. Apply warm water pad on affected site.