Cardiology In Critical Care
Sinus Tachycardia (ST)
Impulses originate in the SA node at a rate 100-160/min in adults (and up to 200 or more in children). P upright in L2 and negative in AVR with identical or slightly different size and contour from beat to beat. At very rapid rates P superimposed on preceding T. When P recognizable, P:QRS ratio 1:1. Tachycardia usually appears and subsides gradually. Vagal stimulation produces gradual slowing which reverses when pressure is released. Exercise further increases the rate.
|Rhythm||P Wave||PR Interval
|> 100 bpm||Regular||Before each QRS, identical||.12 to .20||< .12|
There have been Visitors to this website.
Return to Nurse Bob's™ Page