Sinus Tachycardia

A condition in which the heart rate is faster than normal because the sinus node is sending out electrical impulses at a rate faster than usual.

Most commonly, sinus tachycardia occurs as a normal response of the heart to exercise when the heart rate increases to cope with increased energy requirements. Sinus tachycardia can be completely appropriate and normal, such as when a person is exercising vigorously. However, it may cause symptoms such as weakness, fatigue, dizziness, or palpitations if the heart rate becomes too fast to pump an adequate supply of blood to the body.

Sinus tachycardia is often temporary, occurring when the body is under stress from exercise, strong emotions, fever, or dehydration, to name a few causes. Once the stress is removed, the heart rate will return to its usual rate.