What causes swollen or enlarged heart? My first brother in law died from this and now my 2nd brother in law is diagnosed with this. Needless to say, I'm scared for my husband. I really don't know their exact histories. But the first drank quite heavily which started during his divorce but never smoke. The second never drank but smokes. Both have dry nagging cough which the doctor said is the side effect of the enlarged heart irritating the lungs. This was what the family members told me. Hv, what do you think? And what can one do to prevent this?