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Heart Disease in Women
Other Heart Drugs
ACE Inhibitor Drugs
Calcium Channel Blockers
|What Are Beta Blockers?
Beta blockers are a group of drugs which are used for coronary heart disease treatment as well as for treating angina (pain in the chest due to restriction of blood flow) and heart arrhythmias (abnormal heartbeat). They may also be used for high blood pressure (hypertension) but not usually as a first line of treatment. Doctors may also prescribe the medications for the treatment of heart failure (cardiomyopathy/disease of the heart muscle) and to patients who suffered a heart attack.
Sometimes they are used to treat non-heart related conditions such as anxiety, glaucoma and migraines. Beta blockers include medications such as bisoprolol, atenolol, labetalol, carvedilol, metoprolol, nadolol, pindolol, timolol and propranolol.
Common Brand Names
|Generic Drug Name
||Lopressor; Toprol XL
||Tenormin; Atecor; Amolin; Atenogen
What Do They Do?
Beta blockers work by interfering with the way the body naturally responds to stress and exercise. When the body responds to stress our sympathetic nervous system releases adrenaline hormones (epinephrine) and noradrenaline hormones (norepinephrine). These hormones cause the heart to beat faster so that more blood and oxygen is pumped around the body. This results in a temporary rise in blood pressure. A beta blocker blocks the effects of these hormones at the nerve endings known as beta receptors. The heart becomes more relaxed and less prone to reacting to stress. It slows down and does not pump as hard as it normally would during exercise or times of stress. This has the additional benefit of lowering blood pressure. Beta blockers are an important medication for treating all sorts of heart diseases because they help to reduce the work load of the heart. This is particularly important for someone with damaged heart muscle after a heart attack or stroke. It is also important for someone suffering coronary heart disease (CHD) which is caused by the buildup of atherosclerosis (fatty deposits) in the arteries. The buildup of atherosclerosis causes blockages which restrict blood flow and leads to angina attacks when the heart pumps faster and has a higher demand for blood.
Types of Beta Blockers
There are 2 types of beta receptors in the body: beta1 and beta2. Beta1 receptors are mainly found in the heart and beta2 are found in all other parts of the body. Certain beta blockers drugs, such as metoprolol, atenolol and bisoprolol are called cardioselective because they mostly act on blocking beta1 receptors. These are the blockers that are principally used for treating heart complications. Noncardioselective beta blockers work on beta2 receptors. These drugs include timolol, oxprenolol and propranolol and they may be given to treat migraines and other non-heart related disorders.
When Are They Used?
If your doctor prescribes beta blockers as a treatment for angina, the drugs will enable your heart to work longer during exercise or times of stress before an angina attack occurs. You will need to take beta blockers daily along with your nitrate medications. If you suffer from angina, check out books on heart disease. There are many things you can do yourself to improve your condition.
Nearly all patients who have suffered a heart attack are prescribed beta blockers indefinitely to prevent the risk of a second heart attack. After a heart attack the muscle in the heart starts to remodel in response to the damage it has suffered. Remodeling is not good for the function of the heart and beta blockers help limit it from happening.
If a patient suffers congestive heart failure the heart becomes weak and cannot pump blood around the body as well as it should. Although the failing heart may continue working, it will do so at a limited capacity so that the person becomes easily tired and short of breath (see, symptoms of heart failure). It may seem strange to prescribe heart failure patients medications which slow the heart further, but studies show that beta blockers do prolong their life. It is believed that by slowing down and relaxing the heart the medications also slow down further deterioration, which happens to nearly all heart failure patients.
Atrial Flutter and Atrial Fibrillation
Beta blockers can be used as antiarrhythmics to slow down the electrical system of the heart in patients with atrial flutter and atrial fibrillation. Atrial fibrillation is a common type of heart arrhythmia where the heart's electrical impulses happen too quickly causing irregular heartbeats. Atrial flutters are similar but they cause faster, regular heartbeats. Both conditions can lead to stroke in women.
High Blood Pressure
As beta blockers slow down the pumping action of the heart, this has the knock on effect of lowering blood pressure. Beta blockers are not usually the first line of treatment for high blood pressure unless the patient has another condition which will benefit from the drugs, such as heart failure or a previous heart attack.
Migraines and Other Conditions
Certain types of beta blockers (noncardioselective), including propranolol, timolol and oxprenolol may be prescribed to prevent migraine attacks. They work by acting on the tiny blood vessels in the head. They may also be used for controlling thyrotoxicosis, an overactive thyroid gland. Timolol is sometimes added to eye drops to treat glaucoma - it works by lowering the production of fluid found in the eye which reduces pressure in the eyeball.
Stress and Anxiety
Beta blockers (in particular, propranolol) are sometimes prescribed to people who suffer from anxiety and experience physical symptoms such as trembling or shaking hands when stressed. They are often used by musicians for example who become nervous or shaky before a concert. This ‘condition’ is known as situational anxiety. The medications are not addictive nor do they cause drowsiness. In fact research by the Ohio State University Medical Center suggests that propranolol improves a person's ability to think flexibly under stressful conditions. This has led to its use by some public speakers. Beta blockers for treating situational anxiety can be taken as required; they do not need to be taken daily.
What Are The Side Effects?
Although beta blockers are well established medications, they can cause a number of side effects, including:
1. They may worsen heart failure in patients who are not ready to take them.
2. Muscle fatigue or fainting after exercise.
3. Shortness of breath and wheezing in people with lung conditions such as asthma, chronic bronchitis and emphysema.
4. Light-headedness in some people with diabetes if the drug interferes with their ability to know when to recognize when their blood sugar levels are too low.
As the drugs interfere with the sympathetic nervous system they may cause:
5. Depression, read more in our article side effects of depression.
6. Sexual dysfunction.
9. Coldness in hands and feet.
If you experience any side effects contact your doctor immediately. She may prescribe a different brand of beta blocker which may resolve the issue. Important: Never suddenly stop taking beta blockers or miss dosages as this can worsen cardiac symptoms and cause a significant rise in blood pressure.
Testing For Heart Disease
Drugs such as beta blockers are often only prescribed after heart disease testing procedures have been carried out. Possible tests include:
Echocardiogram (Echo) - similar to ultrasound scan.
Exercise Stress Test - also known as the treadmill test.
Chemical Stress Test - alternative to exercise stress tests.
Heart Catheterization - invasive procedure to check arteries.
Coronary Angiography - gold standard for diagnosing CHD.
Nuclear Heart Scan - extensive test for the heart.
Holter Monitor - 24 hour heart monitor.
Event Monitor - Heart monitor which is worn for 4 weeks.