Normally the heart beats between 60-100 times per minute. In people who exercise routinely or 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 an occasional extra heart beat is known as extrasystole.

Palpitations are often not serious. However, it depends on whether or not the sensations represent an abnormal heart rhythm (called an arrhythmia). You are more likely to have an abnormal heart rhythm if you have:

• Known heart disease at the time the palpitations begin
• Significant risk factors for heart disease
• An abnormal heart valve
• An electrolyte abnormality -- for example, low potassium

Heart palpitations can be caused by:

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

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.

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 their seriousness and the cause.

Once a serious cause has been ruled out by your doctor, try NOT to pay attention to heart palpitations, unless you notice a sudden increase or a change in them.

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 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

Try to reduce stress and risk factors for heart disease:

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