Dr. W. Gifford-Jones: When the heart loses its timing

Dr. W. Gifford-Jones

What does the figure 2,575,440,000 indicate?

It’s not the national debt, or the increase in the world’s population in the next 10 years. Rather, if you live to 70 years of age, your heart will beat this many times. But sometimes it gets weary and develops an irregular rate called atrial fibrillation (AF). So can chocolate help to prevent this problem?

AF is not a rare problem. A report in the journal Circulation says that one-quarter of North Americans will develop this condition at some point during their lives. This is not surprising, since electrical equipment tends to be unpredictable.

We know cars get into trouble when their electrical systems falter. It’s the same problem with the heart, as its beats are controlled by an electrical mechanism located in the right upper chamber. And when atrial fibrillation occurs, it’s because electrical activity has become random and erratic, causing the two chambers of the heart to quiver and twitch.

Electrical dysfunction can be caused by a variety of problems. In many cases, it’s the price we pay for our success in treating other heart conditions. For instance, many patients who used to die from coronary attack are now being saved, but some are left with a damaged, scarred electrical system.  

The “holiday heart syndrome” is not the result of a seaboard romance. Rather, AF may develop from excessive use of alcohol. It can also result from an overactive thyroid. Several years ago the first President Bush required treatment for AF due to this disease. AF is also prone to occur during the few days following coronary bypass surgery or in those who are obese or diabetic.

Some patients who develop AF may be unaware of it. Others notice palpitations, an irregular heart rate, breathlessness or fatigue as the heart rate increases from 70 to 300 or more beats a minute. But don’t quickly diagnose AF when you think your heart has skipped a beat or two.

Others have what’s called “paroxysmal AF.” It’s the type that may last minutes or several days and then stops on its own. The rest have the continuous type.

Regardless of type, atrial fibrillation results in blood staying longer in the upper chambers of the heart, not an ideal situation as the longer blood swirls around in one place, the greater the risk of blood clot and stroke. Studies show that if AF is present the risk of sudden death is between 4 and 10 percent.

Dr. Hugh Calkins, professor of medicine at Johns Hopkins, says that the use of Coumadin or Aspirin decreases the risk of blood clot and stroke. But these drugs, by making the blood too thin, may cause bleeding and stroke. In this situation, you’re between a rock and a hard place. Fine tuning is required to ensure that the benefit of drugs is greater than the risk.

Other drugs are also prescribed to decrease the rate of the heart and restore normal rhythm. But these can be a problem too, causing nausea, dizziness, fatigue and palpitations. If these result, the next step is to consider the pros and cons of “catheter ablation,” a way of regulating the abnormal electrical system that’s triggering AF.

During a catheter ablation, a tiny flexible tube is inserted into a vein in the groin. Then, using fluoroscopy, the catheter is threaded up the vein and into the atrium of the heart. Electrodes in the catheter’s tip pinpoint the area of abnormal electrical activity and, by use of radio waves, destroy it. This procedure is effective in about 70 percent of cases

I’ll end this column on a happy note by adding a little chocolate. I’m not suggesting it’s the way to treat or prevent AF — for that, I’d be charged with professional misconduct. But dark chocolate contains magnesium, a mineral that’s vital to maintaining normal rhythm of the heart.

Today many people, due to dietary habits, or those living in soft water areas, consume low levels of this mineral. Deficiency may also be due to water pills, excessive amounts of caffeine or too many martinis.

I admit its better to get this mineral by eating more nuts, fiber and dairy products. But a little therapeutic chocolate sometimes makes this world seem a better place!

See the Web site      

Dr. W. Gifford-Jones is actually Dr. Ken Walker, a practicing physician in Toronto who writes many columns at his Bristol Harbour, N.Y. residence.