heart attack
"Began 6 months after attack a very low dose (1/2 per day of smallest dosage pill)

Began sleeping 12 to 16 hours each day. Also, seemed not to care about anything- said inappropriate comments, pulled out into traffic recklessly, and damaged gardening equipment. Nothing seriously bad happened but I had to learn to concentrate differently. After three years I had a number of concerns and stopped taking this med- sexual desire increased as did erections, urine stream strong, fewer trips to the bathroom, and I care about the future again. 

With all that said - I think Metoprolol helped me to recover and I began taking it again, but I am going to talk to my doctor about discontinuing it."