Are heart palpitations dangerous? A doctor explains what happens when your heart seems to skip a beat.

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rabbit-heart-palpitationsby Eva F. Briggs, M.D.

Q. What are heart palpitations? Should I be concerned about them? Also: I don’t understand how my heart can skip a beat and it doesn’t cause any damage! Why doesn’t it?

A. On television and in the movies, the human heartbeat is portrayed as steady as a metronome: lub-dub, lub-dub, lub-dub. But our hearts aren’t mechanical, and sometimes Mother Nature skips a beat, or sneaks one in early. When that happens, you feel the irregularity as a peculiar thump or fluttering sensation: a palpitation.

What Causes Heart Palpitations?

Most palpitations are not dangerous. They’re due to minor system glitches.

Your heart has a built-in pacemaker. Sometimes the atria (upper heart chambers) or ventricles (lower heart chambers) jump in before the pacemaker fires. The result is an early beat, called a premature contraction. The heart often responds by delaying the next scheduled beat.

People may not even notice the early beat, but perceive the interval until the second, delayed beat as a skipped beat. The body is actually maintaining the overall balance and continues to function without any harmful effects on circulation.

One common reason for these premature contractions is epinephrine. Sometimes called the fight-or-flight hormone, epinephrine can increase your heart rate, often causing rapid or early beats felt as palpitations. Your body makes more epinephrine when you’re frightened or stressed. That explains why your heart seems to thump right out of your chest during a scary movie.

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When Are Heart Palpitations Dangerous?

Sometimes palpitations do indicate a heart problem. Warning signs for underlying serious problems include:

  • Continuous palpitations—over six per minute or three in a row.
  • Lightheadedness
  • Shortness of breath
  • Passing out
  • Chest pain

Potential serious causes of heart palpitations include:

  • An overactive thyroid
  • Blockage in the coronary arteries
  • Electrolyte imbalances (sodium, potassium)
  • Diseases of the heart muscle
  • Abnormalities in the heart’s electrical system
  • Malfunction of the natural pacemaker

(The last two can lead to the heart not beating efficiently, potentially weakening it.)

What Are the Tests for Heart Palpitations?

To help find the cause of palpitations, your doctor will likely perform an electrocardiogram (EKG). This simple test records the heart’s electrical activity through electrodes attached to the chest. The tracing provides information not only about the heart’s rhythm, but also about its size, evidence of prior structural damage and possible delays in the electrical signals.

Often, the troublesome palpitations don’t happen while you’re at the doctor’s office. In that case, your doctor may hook you up to a portable monitoring device that records the heart rhythm as you go about your daily routine. Depending on the doctor’s initial findings, he or she may order additional tests such as blood work or an echocardiogram (sound wave picture of the heart).

What Is the Treatment for Heart Palpitations?

If nothing serious is causing the palpitations, the first treatment step is generally lifestyle modification, such as cutting back on caffeine and avoiding decongestants. (These stimulants can exacerbate palpitations.) Also, regular aerobic exercise leads to a slower baseline heart rate that’s less susceptible to palpitations.

Prescription medicines are reserved for the most stubborn cases. The most commonly used drugs, called beta-blockers, act by slowing the heart rate.

Luckily, most people won’t need medicines to treat palpitations that aren’t due to heart disease or illnesses. Sometimes the reassurance that your heart is normal is enough to make the palpitations less scary and therefore less noticeable. Remember that even though it seems as if your heart is going haywire, it’s still pumping all the blood required by your brain and other vital organs.

But if you have any question at all, see your health-care provider to make sure of the cause.

EVA F. BRIGGS, M.D., is a board-certified family physician in Marcellus, N.Y.

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Original version appeared in May/June 2008 issue of My Family Doctor magazine. This general health-care information is not meant as individual advice. Please see our disclaimer.

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