Sorry to throw a monkey-wrench into the works, but my experience with metoporol was terrible, and the brand name Toprol was only somewhat better. First of all, its primary purpose in slowing my heart rate didn't work too well, with my resting pulse over 80 bpm on 200 mg at the hospital. It was very disconcerting seeing the rest of the cardiac patients with nice slow pulses about 45-65 bpm on the telemetry strips, while mine seemed to be positively hopping in comparison. Later I felt horrible depression, breathing difficulties, partial blindness (mostly left eye) that would hit several times a day for a couple of minutes, forgetfulness, 'heavy leg' syndrome (where you feel partially paralyzed from the waist down, but I could still stand up with extreme concentration), and very low blood pressure (i.e. 90/65 and the like). On lower doses my pulse rate went up to 90, and the heavy leg syndrome got better, but most of the other side-effects remained, including a definite increase in hair loss--temporary as it turned out. There were some other symptoms, but due to the memory problems at the time, I can't recall exactly what they were. It was enough that Laura insisted that I be taken off the metoporol and put on the Toprol XL at 25 mg/day. Even then, it didn't really help my heart rate much, and the side-effects remained. Finally, about 3 months post-surgery, I was taken off the Toprol altogether. My pulse rate remained at 90 bpm for a few more months until I became much more physically active in the spring and summer of 2008, where it settled down into the 70s. Now it varies from 70s when I've been most physically active to 90s resting when I'm less fit. Despite the higher heart rate, the incidence of dangerous side-effects for me makes taking metoporol or any other related beta-blocker too risky for either me or Laura to swallow. I never suffered any arrhythmia, so I shouldn't worry about it.
I'm sincerely glad that those of you with positive experiences with metoporol and Toprol continue to do so. I just needed to be honest, but I also want to state that what happened to me is quite rare, so those of you who are worried about what you read here shouldn't worry about it too much. Just look out for the stuff mentioned and report it immediately to your doctor in the unlikely event of these side-effects happening.
Chris