I ve been taking Toprol for over ten years. I d been diagnosed with three leaky valves, was hypertensive and experiencing low leg swelling. Just about 4-5 months ago I began experiencing more frequent bounding, rapid heartbeats, irregular heartbeat, shortness of breath with mild exertion and anxiety, like when having to rush to get ready to leave the house. After a few months of symptoms, including increase in irregularity and rapidity of same,add well as an overall slowing now of my pulse, I went to the doctor. I ve had a couple strange and symptomatic episodes in the past when I d gone in, and even twice to the ER, with no findings, so I d been just hoping it would go away! The first cardiologist I saw said basically that I really didn t have anything wrong. However I was still symptomatic so decided I would see someone else. Then I received a call from the office saying their electrophysicist cardiologist had reviewed my halter and wanted to see me. He explained that he was concerned about some of my heart rythms(can t remember exactly what!) as well as my pulse rate was often slow,below 70,and didn t vary according to activity as he expected,and he wanted to do a modified stress test. I haven t tolerated a full test for years and I m only 64, but I have fairly mild lupus as well, multiple secondary and primary health problems. I told him I thought I was deconditioned from all. (I d also, I developed an av block in 2006.). I did this stress test and wasn t able to get my pulse above the mid nineties. He concluded that I needed a pacemaker. I m now 3 weeks post with a double pacer. My heart rate is regular and I ve only felt a couple flutters. On my 2 week post visit he slowed it a little as I felt like it was going too fast for activity, like the high eighties for most in home activity. I went back almost a week later to have staples removed and I mentioned that I noticed in the morning before taking my metopropolal tartrate 50 mg, my heart would really race sometimes. I take 25 mg at bedtime and he suggested I take a full 50 mgs @bedtime also, to see if it would hold over better in the earlier morning. So finally to present and my question, I ve taken it only 2 nights and am wondering about side affects, so I looked those up, not having reviewed them for a long time. I had one particularly extended hot flush yesterday. What I call it when my face just feels so hot and my whole head start sweating like mad. I m much warmer feeling than I should be. I ve had bouts of this off and on in past years and now am wondering about side affects of the Toprol. I also feel really weak and washed out this morning. My BP is 102/58, pulse 72. I ve pretty much taken 75mg over the years cutting it down to 50 and no higher than 100. It seems when the dose is 100 that I have problems with weakness, and maybe that s when I ve had more trouble with the flushing and sweating. I also wonder why I went into the block in 2006. From the Toprol? Is it possible to develop new or recurring side affects off and on during the course of years taking it? They re was also a frightening time when I was having lunch with a friend and things started seeing dark around me and I felt like I was detaching from my environment.I dropped my fork, couldn t eat or talk very well, and felt like I was in a tunnel. Iwas taken to the ER by my friend. Thankfully this never occurred again, but I ve felt on the edge of that sensation a few times and I also get the sensation of something flitting in and out of my peripheral vision at times. It s weird to say the least. As I reviewed side affects, I started wondering how much, if possibly all of these are caused by the Toprol and if so, is it safe for me to continue it? My current and highly qualified doctor diagnosed my problem as sick sinus syndrome and some chronotropic incompetence. Could this possibly even been caused by the Toprol?! I haven t had a chance to discuss this with present doctor, but after years of various health issues, I ve noticed that medication sa s and reactions are really rarely discussed unless I bring up specific concerns. I have a feeling this is a generic problem as it can be so complex to decipher in the end! I d appreciate you addressing my questions and concerns, specifically the possible side affects off Toprol for me and response to them. I gave you background information in hopes of a clearer picture. Thanks very much for your time!