In general there are multiple causes of nipple discharge. In males the most common is caused by what is called "gynecomastia", or enlargement of male breast tissue.
Nipple discharge is more likely to be "normal" if it comes out of both nipples, and happens only when you squeeze them. As a matter of fact squeezing them often, may perpetuate the problem, and leaving the nipples alone may make it go away on its own.
However if nipple discharge comes only from one nipple, is occasionally bloody, or comes out without squeezing, this is not normal, and should be further evaluated.
"Gynecomastia" can be the result of many things, including liver disease, thyroid disease, kidney disease, use of certain medications. You should be checked by a physician to get a full physical exam, including to check for any abnormal lymph nodes in your body, some blood tests and of course a breast exam. This is just to be on the safe side.
I see that you have a history of cardiomyopathy, so if you are taking any heart medication it is possible that some of them may be causing the problem. A well known cardiac medication to cause it is called Verapamil.
In conclusion this is most likely something benign, but you should be checked out by a physician.
Hope that helped! Let me know if you have any further questions.

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