DEAR DR. DONOHUE: Will you answer some questions on atrial fibrillation? I have been electrically cardioverted twice. Is there a procedure, a medicine or a device that ensures my heart stays in normal rhythm? I know other people who have atrial fibrillation and have the same questions. — B.D.

ANSWER: Atrial fibrillation is one of the most common heartbeat disturbances. It’s a very fast and very irregular heartbeat. High blood pressure, plugged heart arteries, deformed heart valves, excessive alcohol use and an overactive thyroid gland are some of its causes.

Atrial fibrillation presents two problems. One is the rapid heartbeat, which exhausts the heart and the patient. The second is the irregular beat. One of its dangers is stagnation of blood in the atria, the upper heart chambers. Stagnant blood clots. Pieces of those clots can be swept in the circulation to brain arteries, where they obstruct those arteries and cause a stroke. This is the reason people with atrial fibrillation take blood-thinning medicines. A fibrillating heart cuts down on the heart’s pumping ability, and that can produce fatigue.

A brief electric shock sometimes can establish a normal heartbeat. The chances for a permanent reversion to a normal heartbeat are best when fibrillation has been present for less than 48 hours.

Medicines can bring the beat back to normal. Two such medicines, and there are many others, are flecainide and amiodarone. If they don’t work, some patients have to settle for drugs that yield a slow but irregular beat. Tenormin and digoxin are two examples. A person often can do quite well with a slowly but irregularly beating heart.

Ablation is a technique in which a doctor introduces a catheter into the heart from a surface blood vessel. The catheter is specially equipped to deliver radio waves to the heart. The waves inactivate the sites in the heart that are responsible for generating the abnormal rhythm. It’s a very involved process requiring a highly specialized heart doctor.

The booklet on heartbeat irregularities discusses this common problem at length. Readers can obtain a copy by writing: Dr. Donohue — No. 107, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I read in one of your columns about how a surgeon handling the intestines during an operation can cause adhesions to form. I have an inguinal hernia for several years and repeatedly push the protrusion back into place. What damage can result from this?

Three of my doctors told me that many people do not have hernia surgery. I have had no success with different hernia belts. — S.A.

ANSWER: What you do and what a surgeon does are two different things. Surgeons have to push organs and intestines to one side to get to the place where they must operate. That can lead to adhesion (scar tissue) formation. You are pushing the abdominal covering (the hernia) back into the abdominal cavity. That doesn’t produce adhesions.

Surgery is the only way to correct a hernia. If the hernia isn’t large, isn’t painful and can be pushed back into the abdomen without trouble, then immediate surgery isn’t necessary. Many people go through life without surgical correction. The belt you used is called a truss. It works for some, but not for all.

DEAR DR. DONOHUE: I have high cholesterol and osteoporosis. I take a calcium tablet, which contains both vitamin D and vitamin K. Since I never eat fish, I am considering taking a tablet with 1,000 mg of fish oil. Will there be an adverse reaction from taking vitamin K and the fish oil? Could they cause a bleeding problem? — S.F.

ANSWER: Vitamin K doesn’t cause bleeding. In fact, it prods the liver into making clotting factors, proteins that contribute to clot formation. Fish oil might interfere with clot formation when it’s taken in large doses. Your dose is not a large dose. The combination won’t lead to a bleeding problem.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.