Narrow-complex tachycardia

Diagnosis

Differential A.Rhythm A.rate A.morphology Vagal/adenosine
A Fib Irregular >350 Fibrillatory (V1) Incr. AV block
A Flutter Regular >250, <350 Sawtooth (II, III, AVF) Incr. AV block
A Tach Regular >100 Neg in II, III, AVF Nothing
AVNRT (SVT) Regular >160 No p's --> NSR
Junctional Regular >100, <150 No p's or retrograde p's Nothing
MAT Irregular >100 >3 p shapes Transient slowing
Sinus Regular

>100 <180

Normal Transient slowing

Flutter vs coarse AFib: determine atrial regularity by taking big bites

Treatment

A fib/flutter

  • Rate control: Dilt, MTP, Digoxin
    • Dig usually only helpful when already w/ a block (e.g. 2:1)
  • Cardioversion: Sotalol, electric

AVNRT (SVT)

  • Vagal, adenosine, BBs, CCBs, dixogin, electric, procainamide, amio, sotalol

Junctional

Remove the cause, Amiodarone, BBs, CCBs

MAT

  • Dilt
  • BBs often contraindicated (MAT occurs frequently w/ pulm dz)

See Also