Q: Would you please explain the difference between atrial fibrillation and arrhythmia palpitations? What can be used to control them?
-- L., Canton, Ohio
A: It sounds like you've recently been told that you have a problem with your heart but you're not sure what it is or whether you have more than one problem.
Understanding your medical situation can be difficult at times. And it can be especially frustrating when health professionals don't seem to have enough time to explain everything or to explain it well.
The muscle contraction, or beating of the heart, is controlled by electrical signals that start in specialized cells within the heart. These signals travel through conducting cells as well as the muscles. In atrial fibrillation, the starting and conduction cells are abnormal. This causes an abnormal rhythm or beating pattern of the heart. Any abnormal pattern is called an arrhythmia.
Palpitations, on the other hand, are a symptom of some arrythmias in which a person feels a beat or lump or grabbing sensation in the chest or lower neck. It typically results from one heart beat occurring too early so that it's very weak and the next heartbeat is extra strong. Atrial fibrillation can cause palpitations on its own, but often there is another abnormality as well.
Palpitations are commonly caused by premature contractions of the ventricles (the large heart chambers) and are called PVCs. These often occur in normal hearts and can be caused by high stress, anxiety and caffeine. However, PVCs, especially if there are a lot of them or if many occur in a row, may indicate a serious underlying heart problem.
Often medical problems are quite straightforward and easy to understand, except for the foreign language they're spoken in. So, for those of you that want to understand more, I suggest you get a medical dictionary. You may have to look up words that are used in the definitions, but eventually the detective in you will understand the meaning.
Medical dictionaries are usually found in large bookstores, or you may be able to order one or use an online bookstore such as Barnes & Noble or Amazon.com.
Update on autism: Usually when the underlying cause of the disease is unknown, we do not have a cure and the disease becomes chronic. But again and again, researchers are discovering that many of these chronic diseases are types of autoimmune disease.
An autoimmune disease occurs when a person's own immune system attacks and destroys healthy cells within the body. This could happen without provocation -- say when a genetic defect occurs spontaneously.
But it's also being found that a viral infection is often the initiating event. In fighting the infection, the body makes antibodies to kill the virus, but these antibodies end up attacking normal tissue as well.
It's recently been reported that autism may be another autoimmune disease. In children with autism, antibodies against nerves and the myelin sheaths that surround nerves are much higher than in children without the disease. In that same study, it appeared that the measles virus is the likely initiator, but the herpes-6 virus may also be involved.
Changes in the nerves caused by these antibodies could explain the devastating symptoms found in children with autism. The most obvious symptoms include poor communication skills and little social interaction. But autistic children may also have stunted imagination and poor reasoning skills.
I hope, as we understand more and more basic immunology, we will better understand why some people develop autoimmune diseases and others don't. Then we will truly be on the threshold of curing many chronic diseases.
Dr. Allen Douma welcomes questions from readers. Although he cannot respond to each one individually, he will answer those of general interest in his column. Write to Dr. Douma in care of Tribune Media Services, 435 N. Michigan Ave., Suite 1400, Chicago, Ill. 60611. His e-mail address is DRFamily@aol.com.