cAn't Find P Waves

If ventricular rhythm is irregular: probable atrial fibrillation

If ventricular rhythm is regular:  
  • Slow and narrow: AV junctional escape rhythm
  • Slow and wide: junctional escape with bundle branch block vs ventricular escape rhythm
  • Fast and narrow: SVT
  • Fast and wide: probable ventricular tachycardia​
If rate is normal:
QRS narrow                                                                
  • accelerated AV junctional rhythm (rare)            
  • sinus rhythm with 1st degree AV block         (search for Ps hidden in the preceding T)         
QRS wide
  • accelerated idioventricular rhythm (rare)
  • ventricular paced rhythm (atrial activity may be atrial fibrillation and treat patient as a. fib e.g. coumadin)