Rapid beating of the heart caused by stimulation of the sinoatrial node.
Heart rate with normal rhythm but elevated rate above 100 beats per minute.
A fast heartbeat originating in the sinus node, the heart’s own pacemaker. Sinus tachycardia is normal during exercise or when a person experiences anxiety. It may also be caused by shock, hypotension (low blood pressure), hypoxia (insufficient oxygen supply), congestive heart failure, or fever.
A regular heart rate of 100 or more beats a minute, caused by increased electrical activity in the sinoatrial node. This level of tachycardia is normal during and just after exercise, and may also be caused by stress or anxiety. If tachycardia persists when the person is resting, it may be due to underlying disease such as thyrotoxicosis and investigation is advisable.
A rapid heart rate (over 100 bpm) originating in the sinoatrial node. It may be caused by fevers, exercise, dehydration, bleeding, stimulant drugs (e.g., epinephrine, aminophylline), thyrotoxicosis, or many other diseases or conditions.
A rapid yet steady heart rate exceeding 100 beats per minute, which results from heightened electrical activity in the sinoatrial node. This kind of heart rate is typical during moments of sudden stress or physical activity. If sinus tachycardia persists while at rest, it could be indicative of conditions like fever or hyperthyroidism.