Cardiology Question 19 Instructor

What are the causes for short RP and long RP interval in narrow complex SVTs?

1. Short RP (R-P < 50% of the R-R interval)
   1. Typical AVNRT
   2. Orthodromic macroentry over accessory pathway
   3. Atrial tachycardia with first degree AV block
2. Long RP (R-P >50% of the R-R interval)
   1. Atrial tachycardia
   2. Sinus node reentrant tachycardia
   3. Atypical AVNRT:
      • Down the “fast” AV node pathway & retrograde conduction up the “slow” pathway
3. Orthodromic SVT with prolonged V-A conduction
   • Slowed conduction over accessory pathways
   • More common as increased frequency of EP ablation for AVNR