mitral valve prolapse
"I have been on Bystolic 5mg for 1 month. I have mitral valve prolapse. A have really rapid heart rate at times. Had been on Lanoxin abd verapamil of years. All at once my heart rate was very rapid and  my blood pressure raised. I was feeling so nervous. They took me off the medicines I was on and put me on the Bystolic. Within a couple of days my heart rate slowed down and my blood pressure was normal. I feel great again at age 70. The only thing I have noticed is I do have diarrhea once in awhile. This has gotten better after a couple of weeks of taking this medicine. It is working for me so far!"