Welcome to HCM,
Carvedilol is a Non-cardiac selective Beta blocker
hence this can cause bronchospasm
as its side effect,but you are taking it for 6 years,if you are taking it for high blood pressure
there are many other option for control of blood pressure.
level is so low please see your chest physician, If you have bronchospasm you will need inhalation of bronchodialator drugs and if it is absolutely necessary to use Beta blocker cardioselective in low dose can be used.
Otherwise Calcium channel blockers are best as they cause bronchodalation hence will be useful for you.
Please do not take any medicine by yourself please discuss with your Physician and then take according too Prescription.