Sinus tachycardia (also colloquially known as sinus tach or sinus tachy) is a sinus rhythm with an elevated rate of impulses, defined as a rate greater than 100 beats/min (bpm) in an average adult. The normal resting heart rate in the average adult ranges from 60–100 beats/min. Note that the normal heart rate varies with age, with infants having normal heart rate of 110–150 bpm, in contrast to the elderly, who have slower normal.
ECG characteristics:
- Rate: Greater than or equal to 100.
- Rhythm: Regular.
- P waves: Upright, consistent, and normal in morphology (if no atrial disease)
- P–R interval: Between 0.12–0.20 seconds and shortens with increasing heart rate
- QRS complex: Less than 0.12 seconds, consistent, and normal in morphology.
ECG strip example of sinus tachycardia
ECG strip example of sinus tachycardia
