Dear Herma ,
I know from personal experience Chemo can effect the heart but usually only on a temporary basis (?six weeks?). Protein around the heart is very unlikely to be related to chemo or indeed myeloma but may due to a related condition called amyloidosis . Further information is available on this website but you should get further clarification at the royal free which i think is the national centre for Amyloidosis.
Best wishes Michael