Supravetricular Tachyarrhythmias Part 2 Rey Vivo, MD Assistant Professor of Medicine Texas Tech University Health Sciences Center

Objectives Describe the AVNRT Recognize and differentiate the Supraventricular Tachyarrhythmias PRACTICE, PRACTICE, PRACTICE!!!

Review of last week Two most important aspects of arrhythmias: The two mechanisms that produce arrhythmias are: Automaticity (problems of impulse formation) 2. Block or Reentry conduction) Two most important aspects of arrhythmias: 1. Their mechanism 2. Their site of origin

SVTs Accelerated Automaticity Reentrant Atrial Tachyarrhythmias Sinus Tachycardia Atrial Tachyarrhythmias e.g. PAT with Block, MAT 3. Accelerated Junctional Rhythm Reentrant Atrial Tachyarrhythmias Atrial Flutter Atrial Fibrillation Reentrant Junctional Tachyarrhythmias - The Atrioventricular Nodal and Bypass Tachycardias

RJT Reentrant Junctional Tachyarrhythmias AVNRT – Atrioventricular Nodal Reentrant Tachycardia Atrioventricular Bypass Tachycardia

AVNRT • Rate: 140 – 220 beats/minute • Usually 1:1 atrial-ventricular association • Every QRS has a P (concealed, fused or retrograde)

AVNRT

AVNRT

SVT Differentials SVT Rate Rhythm P wave Adenosine effect Sinus tach 100 - (220-age) Regular Discrete anterograde P waves Gradual slowing, then reaccelerates AAR 140 - 250 “Not sinus” antegrade P Gradual slowing to reveal atrial activity MAT > 100 Irregular > 3 different forms in 1 lead NA AJR 60 - 130 Inverted, absent or after QRS Flutter A: 220-430 V: <300 Regular or Reg. Irreg. F waves Fibrillation A: 350-650 V: slow to rapid Irreg. Irreg. f waves AVNRT 140-220 (A:V 1:1) Absent or discrete retrograde P waves “Breaks” abruptly, converts to sinus

Narrow Complex Tachs Regular Irregular “Normal” ante Ps..ST Abnormal Ps Rate < 140……….AJR Rate > 140 Ante P…………AAR No or Retro P...AVNRT F waves………….Flut Irregular Polymorphic Ps…..MAT f waves…………….Fib (Reg. irreg, F……...Flut)

Let’s practice! Bix rule Whenever the P of an SVT is halfway between QRS complexes always suspect that an extra P is hiding within the QRS

EKG 1

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The End