Normally the heart beats between 60 and 100 times per minute. In people who are physically very fit (those who exercise routinely) and in people who take medications that slow the heart, the rate may drop below 55 beats per minute.

If your heart rate is very fast (over 100 beats per minute), this is called tachycardia. An unusually slow heart rate is called bradycardia, and if you feel an occasional extra heart beat this is known as extrasystole.

Most people who complain about palpitations do not have heart disease, although many are concerned about the possibility.

Serious or concerning palpitations depends on whether the sensations represent an abnormal heart rhythm (called an arrhythmia) or not. You are more likely to have an abnormal heart rhythm if you:

• Already have heart disease at the time that the palpitations begin.
• Have significant risk factors for heart disease.
• Have an abnormal heart valve.
• Have an electrolyte abnormality.

Conditions or circumstances that may bring on heart palpitations include:

• Exercise
• Anxiety, stress, or fear
• Fever
• Caffeine, nicotine, cocaine, or diet pills
• Overactive thyroid
• Anemia
• Hyperventilation
• Low levels of oxygen in your blood
• Medications such as thyroid pills (like levothyroxine or Synthroid), asthma drugs (for example, theophylline and some inhalers), beta blockers for high blood pressure or heart disease, or anti-arrhythmics (medications to treat an irregular heartbeat can sometimes cause a different irregular heart rhythm)
• Mitral valve prolapse -- a condition in which the valve that separates the left upper chamber (atrium) from the left lower chamber (ventricle) of the heart does not close properly
• Heart disease
• Electrolyte abnormality -- for example, low levels of potassium

Reducing stress and anxiety can help lessen your heart palpitations. Try breathing exercises or deep relaxation (a step-by-step process of tensing and then relaxing every muscle group in your body) at the time of your heartbeat sensations. Also, consider practicing yoga or tai chi on a regular basis to reduce the frequency of your palpitations.

At first, it is helpful to keep a record of how often you have palpitations, when they happen, how long they last, your heart rate at the time of the palpitations, and what you are feeling at the time. This information may help your doctor figure out both the seriousness and the cause of your palpitations.

However, once a serious cause has been ruled out by your doctor, it is important NOT to fixate on your heart palpitations. Try not to pay attention to them, unless you notice a sudden increase or a change in the quality.

If you have never had heart palpitations before, bring them to the attention of your doctor. He or she will do a work up to determine the cause and whether they are treatable or not.

Call your local emergency number (such as 911) if:

• You have fainted or someone you are with loses consciousness.
• You have shortness of breath, chest pain, unusual sweating, dizziness, or lightheadedness.

Call your doctor right away if:

• You feel frequent extra heartbeats (more than 6 per minute or coming in runs of 3 or more).
• You have risk factors for heart disease like high cholesterol, diabetes, or high blood pressure.
• You have new or different heart palpitations.
• Your pulse is more than 100 beats per minute (without exercise, anxiety, or fever).

Your doctor will take a medical history, perform a physical exam, and do an EKG. If you are in distress (meaning that you have chest pain, shortness of breath, or other concerning symptoms) and are in the emergency room, your cardiac rhythm will be monitored. An emergency intervention will be performed if necessary to restore normal cardiac rhythm.

If you do not have the symptoms at the time of your visit, the doctor will want to know what your pulse was at the time you felt the palpitations and whether or not the rhythm felt regular.

Medical history questions may include:

• Do you feel skipped or stopped beats?
• Does your heart rate feel slow or fast when you have the palpitations?
• Do you feel a racing, pounding, or fluttering?
• Is there a regular or irregular pattern to the unusual heartbeat sensation?
• Did the palpitations begin or end suddenly?
• When do the palpitations occur? In response to reminders of a traumatic event? When you are lying down and resting? When you change your body position? When you feel emotional?
• Do you have any other symptoms?

• EKG
• Ambulatory cardiac monitoring (for example, a Holter monitor is used for 24 hours; other monitors may be worn for two weeks or longer)
• Echocardiogram
• Electrophysiology study (EPS)
• Coronary angiography

To lessen your chances of getting heart palpitations, you can try to reduce stress and decrease risk factors for heart disease:

• Don't smoke or quit smoking.
• Eat a well-balanced, low-fat diet.
• Exercise regularly.
• Try stress managment techniques like yoga, tai chi, or meditation.
• Make sure that your blood pressure and cholesterol are under control.