This overview is a sample of the type of information available to you at Griffin Hospital's Community Health Resource Center. It is not intended to replace your physician's instructions in the management of your health problems, but to better inform you about a particular illness and alert you to the availability of other materials. If you have a question about any piece of information presented in theses fact sheets, please call your physician, or stop by the Community Health Resource Center at your convenience.

CARDIAC ARRHYTHMIA

Cardiac arrhythmias are an abnormality of the rate or rhythm of the heart beat. There are two main types of cardiac arrhythmias: tachycardia (fast heart beats) and bradycardia (slow heart beats). With the tachycardia, the heart rate is faster than 100 beats per minute The heart rhythm may be regular or irregular. The normal heart rate for adults is usually between 60 and 100 beats per minute.

WHAT CAUSES IT?

A common cause of cardiac arrhythmia is coronary heart disease. Coronary heart disease happens when the blood vessels to the heart are clogged by fatty deposits. The lack of adequate blood supply leads to injury of the heart's electrical system, which controls the heart's rate and rhythm. Certain areas of the heart send out electrical impulses which stimulate the heart to beat. When these areas do not receive the blood supply of nutrients, the electrical impulse misfires, leading to an arrhythmia.

Certain heart conditions can cause an arrhythmia: rheumatic fever, congenital heart disease or defects (having since birth), having had previous heart attacks or cardiomyopathy (a chronic heart muscle disorder). Sometimes one of the valves in the heart which helps control the blood flow can be misshapen or cannot function properly. This can also cause arrhythmias.

An arrhythmia may occur when there is a disorder of the thyroid or adrenal glands, an imbalance in the body's potassium level, or following chest or heart surgery. Some medications can cause cardiac arrhythmias, either as a side effect (especially with the medicine digitalis) or if too much is taken.

WHO GETS IT?

Anyone can be affected by an arrhythmia (heart rhythm irregularity) but it usually occurs in a person over the age of 65.

The risk of having an arrhythmia is increased by smoking, not getting enough sleep, taking amphetamines ("uppers"), being under too much stress, or having a chronic kidney disease or high blood pressure. The use of caffeine, alcohol or many over-the-counter cough and cold medicines may also bring about an arrhythmia.

WHAT ARE THE SYMPTOMS?

If you are having a cardiac arrhythmia, you may feel your heart suddenly change its rate or rhythm. It may speed up, slow down, become irregular, or skip beats, depending on the arrhythmia.

Sometimes symptoms occur that are a result of the arrhythmia: feeling lightheaded or faint, weakness, shortness of breath with difficulty breathing, confusion or chest pain. These can all be due to a decreased blood flow to the brain, heart and lungs

In an older person who has heart disease, arrhythmias may cause more serious symptoms such as convulsions that are sometimes fatal.

Some people have no symptoms at all.

DIAGNOSING

Your doctor will examine you, listen to your heart, feel your pulse and ask about your symptoms. The next step is to obtain an EKG or ECG (electrocardiogram). The EKG shows the heart muscle's electrical activity. This is usually the best way to diagnose a cardiac arrhythmia. Sometimes the arrhythmia comes and goes. If this happens, your doctor may order a Holter monitor. This is a portable heart monitor that records your heart's activity for 24 hours. Blood studies (lab tests) are usually ordered as well as x-rays of the heart. Occasionally more complex studies will be needed.

TREATMENT

Your doctor will try to find the cause of your arrhythmia to decide how to treat it. Your doctor may prescribe medicine to control your heart's irregularity. He or she may need to try several different medicines before finding the one that is right for you.

Sometimes a cardiac arrhythmia will happen suddenly after a heart attack. This can be life-threatening. A brief electrical shock to your heart (defibrillation and/or cardioversion) may be needed.

If the electrical impulse for the heart is blocked, a pacemaker may be needed to stimulate or control the heart rate or rhythm. A pacemaker is a small, electrical device inserted under the skin of the chest in surgery. Thousands of people every year have pacemakers implanted.

WHAT CAN YOU DO?

You may need to change some of your habits to help prevent the arrhythmias from recurring. This may include eliminating caffeine from your diet (coffee, tea, colas, chocolate), not smoking, and getting enough exercise and rest.

If stress is a problem in your life, sometimes counseling or relaxation exercises can help. Learn to take your pulse.

Sometimes medicine your doctor prescribes for you can cause side effects. Let your doctor know if you experience any new symptoms.

If you know someone with heart disease, you may want to learn CPR (cardiopulmonary resuscitation). This could help save a life.

COPING

Learning to live with heart arrhythmias can be difficult. Arrhythmias can be frightening and make you feel vulnerable. It may help to talk to someone such as a family member, friend, or chaplain. There may be a support group in your community that could share information with you on how others have learned to live with their heart arrhythmias. Call your doctor, nurse or the Planetree Health Resource Center for more information.

Please note that this information is intended to give you a general overview of the topic. It is not intended to replace advice or instruction of a health professional. We recommend that you consult your physician, nurse, or qualified health professional regarding the information in this publication. © 1994 Planetree, Inc. Reproduction of this material in any form is limited to license agreement.

Planetree Health Fact Sheets are developed by Planetree, Inc., a non-profit consumer health organization, founded in 1978. The Planetree Alliance includes hospitals and libraries which, among many other patient-centered concepts, promote the importance of access to health information for patients, families, and community. For more information regarding affiliation with the international Planetree Alliance, call (203) 732-1365 or visit Planetree, Inc. at www.planetree.org.