SupravetricularTachyarrhythmias

Part 2

Rey Vivo, MDAssistant 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:

1. Their mechanism

2. Their site of origin

The two mechanisms that produce arrhythmias are:

1. Automaticity (problems of impulse formation)

2. Block or Reentry(problems of impulse

conduction)

The two mechanisms that produce arrhythmias are:

1. Automaticity (problems of impulse formation)

2. Block or Reentry(problems of impulse

conduction)

SVTs

• Accelerated Automaticity1. Sinus Tachycardia

2. Atrial Tachyarrhythmias

e.g. PAT with Block, MAT

3. Accelerated Junctional Rhythm

• Reentrant Atrial Tachyarrhythmias1. Atrial Flutter

2. Atrial Fibrillation

• Reentrant Junctional Tachyarrhythmias- The Atrioventricular Nodal and Bypass Tachycardias

RJT

• Reentrant Junctional Tachyarrhythmias

1. AVNRT – Atrioventricular Nodal Reentrant Tachycardia

2. 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 Regular “Not sinus”

antegrade P

Gradual slowing to reveal atrial activity

MAT > 100 Irregular > 3 different forms in 1 lead

NA

AJR 60 - 130 Regular Inverted, absent or after QRS

Gradual slowing, then reaccelerates

Flutter A: 220-430

V: <300

Regular or Reg. Irreg.

F waves Gradual slowing to reveal atrial activity

Fibrillation A: 350-650

V: slow to rapid

Irreg. Irreg. f waves Gradual slowing to reveal atrial activity

AVNRT 140-220

(A:V 1:1)

Regular Absent or discrete retrograde P waves

“Breaks” abruptly, converts to sinus

Narrow Complex Tachs

• Regular– “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

EKG 2

EKG 3

EKG 4

EKG 5

EKG 6

EKG 7

EKG 8

EKG 9

EKG 10

The End