Sinus · Watch
Sinus Tachycardia
● Live · lead II25 mm/s · 10 mm/mV
II
10-second rhythm strip · count the boxes
Rate100–150 bpm (rarely > 220 − age)
RegularityRegular
P wavesNormal; may merge into the preceding T at fast rates
PR intervalNormal, may shorten
QRSNarrow
Key features
- Gradual onset and offset
- Rate varies with activity, breathing, and treatment of the cause