February is designated by the American Heart Association as Heart Month. The “Go Red for Women” campaign of the AHA reminds us that heart disease is still the No. 1 killer of women. It is important to listen to your heart, especially when it is beating rapidly.

A rapid heartbeat, or tachycardia, is faster than your normal heartbeat at rest. Usually a healthy adult heart beats 60 to 100 times a minute. During exercise, the heart, which is a muscle, can beat faster than 100 times a minute.

Heart rate is controlled by electrical signals sent across the cardiac tissues. An abnormality in the heart can produce rapid electrical signals, causing the rate of contraction in the heart’s upper or lower chambers, or both, to increase significantly. This can seriously disrupt normal heart function and increase your risk for stroke, heart attack or sudden cardiac arrest and death. Medical treatment by a cardiologist can help to control the rapid heartbeat itself or manage the disease causing the tachycardia.

When your heart rate is too rapid, the four chambers of your heart have difficulty filling with blood and pumping the blood effectively to the rest of the body. This can cause a lack of oxygenation to your organs and tissues, which in turn causes shortness of breath, dizziness, lightheadedness, racing heart palpitations, chest pain or fainting. Some people experience no symptoms with a rapid heart rate and only become aware of it when it is diagnosed during a physical exam or an electrocardiogram.

Rapid electrical signals to the heart can be caused by damage to the heart tissue from heart disease or congenital abnormalities of the heart or its electrical pathways. Other causes include hypertension, smoking, heavy alcohol or caffeine consumption, adverse reactions to prescription medications, an overactive thyroid and abuse of illegal substances such as cocaine. An imbalance of electrolytes — minerals necessary for conducting electrical impulses of the heart — can also cause tachycardia.

Psychological stress or anxiety, age-related wear on the heart and a family history of rapid heartbeat or other heart rhythm disorders can place you at risk for tachycardia. In some cases, the cause of the rapid heartbeat cannot be determined.

Complications depend on the type of tachycardia, the severity of the symptoms, the rate of the heartbeat, the duration of the rapid heartbeat and the existence of any other heart disorders. These complications include heart failure, frequent episodes of fainting or loss of consciousness and the development of blood clots in the heart that can travel and cause a heart attack or stroke.

If you experience tachycardia, contact your physician or go to the nearest emergency department for evaluation, testing and treatment. Treatment is to slow down the heart rate when it occurs, to prevent it from happening again and to decrease the complications associated with it. A rapid heartbeat may correct itself and you may be able to slow it down using physical movements, but you may need medical treatment or medications.

An electrocardiogram, or ECG, records the electrical conduction of your heart. You may need to wear a portable ECG machine at home to provide your doctor with more information. A Holter monitor records your heart’s activity for 24 hours, during which you keep a diary of any symptoms you experience. An event recorder monitors your cardiac activity for weeks or a few months. You activate it only when you experience symptoms of a fast heartbeat.

Your doctor may use vagal maneuvers to slow down your heartbeat, asking you to cough, bear down like you are having a bowel movement or place an icepack on your face. Vagal maneuvers affect the vagus nerve, which helps to regulate your heartbeat. If these have no effect, you may need an intravenous anti-arrhythmic medication to restore your normal heartbeat. If this works, your doctor may prescribe a pill version of the drug. If the IV does not slow your heart rate, cardioversion may be done, in which your heart receives an electrical shock (under sedation) to restore normal rhythm.

If your heart does not respond to any of these treatments, your cardiologist may refer you to an electrophysiologist — an expert in the electrical conduction system of the heart. An electrophysiology study can pinpoint the location of the problem with your heart’s electrical circuit and possibly remedy it. The test is similar to a cardiac catheterization, except the electrode tip catheters are thinner and are threaded into the heart.

Have a plan to deal with an episode of tachycardia. Discuss with your doctor when and how to use vagal maneuvers, when to call a doctor and when to seek emergency care. The most effective way to prevent tachycardia is to reduce your risk of heart disease: Avoid smoking; eat a well-balanced, low-fat diet; exercise regularly and try stress management techniques such as yoga or meditation. Get you blood pressure and cholesterol under control. For more information, visit www.nlm.nih.gov.