HEALTH MATTERS: Your health questions answered

Q. My heart rate usually is between 95 and 100 beats per minute at rest. My doctor did an electrocardiogram (EKG) and said that everything looked normal. Do I need to see a cardiologist?

A. Most healthy people have resting heart rates around 70 or so, with the rate slowing during sleep and increasing during exercise. A rough guide to the maximal heart rate during exercise is to subtract your age from 220. So a 20-year-old is expected to have a maximum exercise heart rate of around 200 beats per minute, while a 70-year-old will only get her heart rate up to about 150.

Besides exercise, many other conditions can indirectly stimulate the heart and cause an increase in the resting heart rate, including anemia, fever, an overactive thyroid gland (recall that we discussed thyroid problems recently in this column), dehydration, a weakened heart, a heart attack, and others.

But when the heart rate is chronically fast and everything else seems normal, as appears to be the case with you, there are a few things that should be checked. One is a blood count (to be sure that there is no anemia), and the other is a thyroid test (to exclude an overactive thyroid gland). If both of those blood tests are normal and you otherwise feel fine, I might stop there.

However, if you have any symptoms, I might do a simple exercise test to see if your heart rate accelerates appropriately, and might also check an echocardiogram (ultrasound) of your heart to make sure that there is nothing structurally wrong. In patients where everything checks out fine, I often start a medicine called a beta blocker to slow the heart rate back toward normal, because such patients often simply have a higher setting of their heart rate “thermostat” than most. The medication usually works, and often without significant side effects.

One of the reasons to consider using the medication is that persistent very rapid heart rates (those well above 100 beats per minute) can actually damage the heart and precipitate heart failure. Although the “damage” caused by very rapid heart rates is reversible, an ounce of prevention is certainly worth a pound of cure.

All of the components of the evaluation that I’ve outlined can be done by your primary care provider, and a cardiologist usually is involved only when patients have persistent symptoms because of the rapid heart rate, or they are concerned that a more serious heart condition exists.

Most patients probably do not need to see a cardiologist as long as the rate is generally below 100 beats per minute, the patient is totally without symptoms, the basic tests are all normal, and there is no suspicion of significant underlying heart disease. But if in doubt, a cardiology evaluation for this problem is usually quick, straightforward, and reassuring to the patient. If you are so inclined, send us a follow-up report, and we’ll share the information. Thanks for sending in your question!

Wynne is vice president for health affairs at UND, dean of the School of Medicine and Health Sciences, and a professor of medicine. He is a cardiologist by training.

Submit a question to Health Matters at healthmatters@med.und.edu or Health Matters, 501 North Columbia Road, Stop 9037, Grand Forks, ND 58202-9037. Remember, no personal details, please.

The content of this column is for informational purposes only and does not substitute for professional medical advice or care. The information provided herein should not be used for diagnosing or treating a health problem or disease. If you have or suspect you may have a health problem, you should consult your health care provider. Never disregard professional medical advice or delay in seeking it because of something you have read in this column.

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