MHVI Owners Manual . Conditions . Heart Rhythm Disturbances . Fast Heart Rhythms

When you exercise, your heart rate increases to help provide your body with enough blood and oxygen to meet your body's extra needs. An increase in heart rate over 100 beats per minute is called tachycardia. Tachycardia is normal when you exercise and is, in fact, desirable for aerobic conditioning.

Tachycardia can also be present with conditions such as fever, anemia, excess thyroid hormone, or congestive heart failure. In these cases, the heart is responding to the increased demands made on the body as a result of these conditions.

Abnormal heart rhythms that are too fast can also develop on their own. If this happens, you might feel a sudden racing of the heart, along with lightheadedness or shortness of breath. These abnormal tachycardias can last for seconds to hours, can be regular or irregular, and can arise from either the upper heart chambers (atria) or the lower chambers (ventricles). Like slow rhythms, tachycardias can be diagnosed by EKG or holter or event monitors. Sometimes an electrophysiology study (EPS) is required to pinpoint the exact cause of the tachycardia.

For more information about these diagnostic studies, see the section in this manual on Diagnostic Testing. The following addresses specific rhythm disturbances.

Choose a topic at left and click for more information on Heart Rhythm Disturbances.