It can be due to
heart muscle
disease, alcohol, drugs medication,
and the
heart can enlarge due extreme physical activity (athlete's heart) over a period of time.. Athlete's heart is not a pathologcal condition, and will return to normal size when the activity is reduced or stopped.
Q: "Are there any signs or symptoms of this condition?"
Shortness of breath, easily fatigued, chest pain (angina)...Dizziness, Abnormal heart rhythm, cough, swelling (edema), Cough.