Change in heart rate or rhythm and fainting

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Change in heart rate or rhythm and fainting

Changes in heart rate or rhythm are called arrhythmias. They may reduce the amount of blood flow from the heart (cardiac output) to the brain and the rest of the body. Decreased blood flow to the brain can cause you to pass out suddenly (syncope). In some cases, you may feel short of breath or have palpitations or chest discomfort before you faint.

Heart rate or rhythm changes also can occur when you are anxious or afraid or in a stressful situation. Feeling worried, anxious, and nervous may increase your heart rate, and you may feel lightheaded or as though you are going to faint.

Changes in heart rate or rhythm that cause fainting can be life-threatening. If you have these symptoms, call your health professional for an evaluation.

If you have heart disease, heart failure, or have had a heart attack, it is especially important to understand the seriousness of a change in your heart rate or rhythm. Call your health professional immediately if you have a sudden change in your usual heart rate or rhythm and you feel faint or lightheaded.

Credits

Last updated:	April 27, 2007
Author:	Jan Nissl, RN, BS
Reviewed By:	William M. Green, MD - Emergency Medicine, H. Michael O'Connor, MD - Emergency Medicine
Editors:	Susan Van Houten, RN, BSN, MBA, Tracy Landauer