Hello Liz,
Beta-blockers are used to treat a range of ailments associated with anxiety and tension, such as high blood pressure, angina, irregular heart rhythms, migraines, prevention of a second heart attack, tremors, alcohol withdrawal, anxiety and glaucoma.
They work by blocking the receptors for the fight or flight response. Beta-receptors are found in a number of places in the body, such as the heart, lung, arteries, brain and uterus. Different beta-blockers tend to affect different areas, with some more appropriate for treating blood pressure and others anxiety, without necessarily affecting performance.
Ok Let's try to simplify this:
When a person is nervous, frightened or physically active, their body produces adrenalin. This makes the heart beat faster and harder. It constricts the blood vessels and raises the blood pressure. It does this by binding to receptors on the membranes of muscle cells in the heart. There are 2 types of these receptors: alpha and beta. All of the beta blockers block the beta receptor. Some also block the alpha receptor. In the case of people with arrythmias this is happening without such activity. Beta blockers work on migraines because their are beta receptors in the brain.
This results is a slowing of the pulse and lower blood pressure. It makes it easier for the heart to work despite narrowed coronary arteries. These effects help control the symptoms of angina.
The most common side effects are weakness and drowsiness. These symptoms reslove promptly when the medication is withdrawn. In diabetics, beta blockers may mask the warning symptoms of low blood sugar.
Some beta blockers may raise the level of triglycerides and lower the level of good cholesterol in the blood.
If you have low blood pressure this would probably not be a good drug to use. Some doctor's try to "kill two birds with one stone", this anti-arrythmic drug does three, lowers blood pressure, dilates the arteries (good for angina) and supposedly has an anti-arhtyhmic effect.
I did not do well on toprol and if you look hard enough on the web you will find that some doctors have found that toprol is contraindicated for people with Lone PAF that are vagally oriented. Because of the slowing of the heart rate this allows your parasympathetic side of your system to have even more pull, causing afib to happen more frequently. It did in me. I think you will find others on this web site who will have similiar experiences. However, please note that some people on this website also do well with the drug and have reported so on this site. Again, this goes back to afib is caused by different things in different people and certain things effect different people in different ways.
If you are feeling that this particular drug is causing you problems, ask your Dr. to switch you. There are over 1 hundred different drugs being presribed for arrythmias. Rhthmol seems to be tolerated well by most people in this board. Check with your Doctor about this possibility and others.
Joe