What is a normal heart rhythm?

With a normal heart rhythm, the heartbeat begins with an electrical impulse in a natural pacemaker (the "sinus node") in the right upper chamber (atrium) of the heart. The sinus node sets a regular, even pace and the impulses are sent across to the other upper chamber and down to the bottom chambers (ventricles) of the heart. The ventricles then pump each heartbeat in regular and even beats.

What are heart rhythm disorders?

Heart rhythm disorders fall under the category of arrhythmias (abnormal heart rhythms). Arrhythmias don't follow the normal heart rhythm pattern described above. Instead, the impulse of an arrhythmia takes a less efficient path through the heart to generate a heartbeat. This can, in turn, cause the heart to beat (pump) less effectively. Abnormal heart rhythms can also cause the heart to beat too slowly or too quickly.

Two general categories of arrhythmias are atrial arrhythmias and ventricular arrhythmias.

• With atrial arrhythmias, the impulse of each heartbeat begins in one of the upper chambers of the heart (the atria).
• With ventricular arrhythmias, the impulse of each heartbeat begins in one of the lower chambers of the heart (the ventricles).

Some arrhythmias cause little, if any, problems. Other arrhythmias may be life-threatening.

What are the warning signs and symptoms of heart rhythm disorders?

A person's response to any specific arrhythmia may vary. There may be no symptoms at all or symptoms may be severe such as collapse or sudden death. In between these two extremes is a wide range of symptoms. These symptoms may include minor palpitations to obvious fluttering in one's chest along with shortness of breath, chest pain, sweating, and lightheadedness.

These are important symptoms to recognize and should not be ignored. These should be discussed with your physician to help determine what is causing them and whether they need to be treated.

How are heart rhythm disorders detected?

Your doctor has several ways of assessing heart rhythm problems.

• The electrocardiogram (ECG) is an easy, pain-free test that shows what rhythm your heart is in. This test, however, only provides information about which rhythm your heart is in at the moment of the test. It does not provide any information as to which heart rhythm you may have had at any time in the past.
• A 24-hour Holter monitor recording or a long-term ECG analysis called an event monitor may provide more information. These tests help assess abnormal rhythms that happen while you are not at the doctor's office. They record abnormal heart rhythms for longer time periods such as 24 hours, 14 days or 1 month. If your abnormal heart rhythm is associated with symptoms, this information would be particularly helpful.
• Other tests that may be helpful include treadmill testing or electrophysiology testing, which is an invasive procedure.

What is the treatment for heart rhythm disorders?

Treatment depends on the severity of the heart rhythm problem. Many heart rhythm problems do not require any treatment at all. Other heart rhythm problems may be easily treated with various anti-arrhythmic medications. Some rapid heart rhythm problems are treated with catheter ablation or insertion of a pacemaker-type device known as an implantable cardioverter defibrillator. Rarely, a person may require an open-heart surgery to eliminate the source of heart rhythm problems.

6/16/2008