Why are beta blockers used?

After being diagnosed with AF, I was prescribed Toprol. It was explained to me that this would slow down the heartbeats thereby providing for more regular rhythm. Why would slowing down the heart beat provide for a more regular rhythm?

My normal heartbeat is slow - do I need this to make it slower?

For those on toprol or metoprolol, did your cardio prescribe that one of your dosages be taken at night? This does not make sense to me since the heart beats slower at night anyways?

Thanks all.

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 These symptoms reslove promptly when the medication is withdrawn.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

Liz:
Your doctor is trying to ensure that when you have an afib episode, the rate will be more tolerable. If your PAF kicks off at 180 bpm without any rate control drug, the hope would be that with a beta blocker on board, your afib episode might start at 100 or 120 and continue to slow until it converts.
My doctor has me take mine at night because my heart rate and BP are normally slow/low and it affects me less if it peaks while I am sleeping. I just have to remember hypotension when nature calls in the middle of the night, and sit on the side of the bed for a moment or I could jump up and pass out. By the time morning rolls around, my BP is around 90/60 which sounds low, but is OK for me.

Pam

My doctor put me on metoprol during my last hospital stay, even though I'm on cardizem. My dosage is 25 mg twice a day and it seems to have helped control my heartrate tremendously.

Liz - in spite of all the reasons why BB are used, I never got along with them and I was on them for about 5 years. They never stopped the arrhythmia but definitely had an effect on my metabolism; I gained weight and always felt as if I were in hybernation. Very low blood pressure and heart rate.

Additionally, BB are known to increase the chances of becoming insulin resistant - which I did.

As soon as I was off the BB, my energy level changed tremendously and I actually felt half alive for the first time in many years.

Then after reading the archives here, I learned BB are not recommended for vagal, but the cardiologists didn't even consider if I was vagal.

My Bp was always very low at night and the nightly dose of Toprol put it even lower and I began systematically and routinely getting afib when the heart rate went way down. Once I eliminated the Toprol, I didn't have those afib events in the early evening - they switched to between 3 and 4 in the morning.

A fast heart beat was never my problem - unless I was in afib - but the Toprol alone did nothing much to control the afib anyway.

I'd certainly quiz your MD about other options.

Jackie

My cardiologists said that I was put on Metoprolol - even though I am vagal, sigh - to make the afib more tolerable - less noticeable. I stopped taking it a long time ago because it made me feel awful.

Carol