A few years ago(Fri. the 13th, LOL) I had my first ride in an ambulance/rescue squad to hospital. I went to my local clinic because normally my heart skipping a beat would go away. This time it didn't. It was skip, then put an extra beat in. Once at hospital no matter what they tried, they could not get my heart to stop. So they upped my metoprolol. I now take 200mgs. once a day. Sure is a lot more than what most people that replied to this are taking. I did have high blood pressure before. I do not drink any caffeine. If it ever happens again I am told that I must immediately go to the ER. So far so good.