ECG Tutorial: Rhythm Recognition

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ECG Tutorial Rhythm Recognition

• Review the systematic approach
• Rhythm the hardest part!
• Again be systematic
• Mind your ps qs follow the rules!
• The Approach Tachy vs- Brady
• Examples
• Quiz

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ECG Tutorial Rhythm Recognition

• My systematic approach
• Rate
• Rhythm
• Axis
• Intervals (PR, QRS, QTc)
• Blocks / Hypertrophy / Enlargement
• Segments (PR, ST)
• Waves (Q-waves, T-waves)
• Ectopy
• Compare to old ECG

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Rhythm Recognition

• Golden rule mind your ps ( qs)
• Step I Is it fast or slow?
• Tachycardia gt100
• Bradycardia lt 60
• Step II Is it sinus rhythm or not?
• 2 questions (rules)
• p with every QRS complex?
• Upright p in I, II aVF?
• Yes to BOTH sinus origin (nice job!)

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Rhythm
Is there a p wave? Sinus
Is it followed by a QRS?
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How does the heart work
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Is the rhythm regular or irregular?
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Tachycardias The Down Dirty

• Common
• Need to recognize the bad boys!
• ACLS, etc
• 2 questions
• Is the QRS narrow (lt0.12 second or 2.5 small
  boxes) or wide?
• Wide complex Tachycardia-vs-Narrow Complex
  Tachycardia
• Is the rhythm regular or irregular?

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Normal Sinus Rhythm Rate 75
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• Sinus Arrythmia
• Typically a normal finding esp. in younger, fit
  individuals
• Due to changes in autonomic tone during
  inspiration

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Tachycardias DDx(Rule of 3s!)

• Narrow Complex Regular
• Sinus Tachycardia
• Atrial Flutter
• Other supraventricular Tachycardia (SVT)
• AVNRT (A-V nodal reentrant tachycardias)
• Atrial reciprocating tachycardia (from
  pre-excitation, ex WPW)
• Ectopic atrial tachycardia
• Other uncommon causes

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Sinus Tachycardiabut why?

• Other causes
• Fever
• Hyperthyroidism
• Effective volume depletion, hypotension
• Sepsis, Shock
• Anemia
• PE
• CHF
• Drugs (stimulants)
• Drug withdrawal (ETOH)
• Pheochromocytoma

• Physiologic (1)
• Response to exercise
• Stress, anger, etc.. (fight or flight)

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Atrial Flutter characteristics?
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Atrial Flutter characteristics?
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• Suspect A-flutter
• Narrow complex tachycardia
• F (flutter waves) rate of 300 (sawtooth)
• Ventricular rate 150 bpm

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Atrial Flutter what is happening in the heart!
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Other Narrow Complex Tachycardiaa - AVNRT
Premature Atrial Complex (PAC)
NSR

• Regular, Narrow-complex tachycardia w/rate
  120-220
• p buried or after QRS (usually) inverted
  (retrograde) in leads I, II aVF
• Most common non-fib/flutter SVT

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AVNRT
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Ectopic Atrial Tachycardia

• Regular narrow complex tachycardia
• Originates outside of the AV node
• Constant p wave morphology
• Constant P-R intervals
• Use the rule of sinus rhythm mind your ps

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Ectopic atrial tachycardia
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Ectopic atrial tachycardiaCan occur with block
(ie-digoxin toxicity)
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Tachycardias DDx

• Narrow Complex IR-regular
• Atrial Fibrillation (irregularly irregular)
• Atrial Flutter with variable A-V block
• MAT (Multifocal Atrial Tachycardia)
• Other Supraventricular tachycardias with variable
  AV block

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Atrial Fibrillation

• The most common arrythmia in older patients
• ECG
• Absent p-waves
• fibrillatory waves vary in appearance
• Irregularly irregular R-R intervals
• Typically narrow complex QRS (unless aberrant
  conduction)
• Bundle Branch Blocks / other blocks
• Re-entry (WPW)
• Rate gt 100 rapid ventricular response (RVR)

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Remember this?
A-flutter with variable AV-block
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MAT Multifocal Atrial Tachycardia

• Narrow complex, irregularly irregular
• Youre thinking A-fib, but
• You see clearly conducted p-waves
• p-waves are not all the same
• You see 3 different p-wave morphologies
• Multifocal
• Varying P-P R-R intervals
• Associated with lung disease (COPD),
  theophylline, hypertension, etc

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MAT
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Narrow Complex Tachycardias - Review

• Regular
• Sinus Tachycardia
• Atrial Flutter
• Other SVT
• AVNRT (A-V nodal reentrant tachycardias)
• Atrial reciprocating tachycardia (from
  pre-excitation, ex WPW)
• Ectopic atrial tachycardia
• Others (uncommon)

• IR-regular
• Atrial Fibrillation (irregularly irregular)
• Atrial Flutter with variable A-V block
• MAT (Multifocal Atrial Tachycardia)
• Others

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Doctorcome quick!
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Wide Complex Tachycardias (WCT)

• A Big Dealmay require emergent treatment!
• A limited Differential Diagnosis
• Ventricular Tachycardia (VT)
• NOT Ventricular Tachycardia
• SVT w/aberrant conduction (Aberrancy)
• SVT w/pre-excitation (ie-WPW)
• What is aberrancy?
• Assume Ventricular Tachycardia until proven
  otherwise
• Esp. in a patient over 40 years old

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Doctor, hurry up read that EKG
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Wide Complex Tachycardia

• Rate gt 100 bpm
• QRS duration gt 0.12 seconds
• Again
• Regular vs- Irregular

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Wide Complex Tachycardia

• Regular
• Ventricular Tachycardia
• A REGULAR SVT w/Aberrant conduction
• Sinus tachycardia
• A-flutter
• AVNRT
• Atrial Tachycardia

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Wide Complex Tachycardia

• IR-Regular
• Ventricular Fibrillation
• An IR-Regular SVT w/Aberrant conduction
• Atrial fibrillation
• Aflutter with variable AV block
• MAT
• Special Case WPW A-fib

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V-Tach vs- SVT w/Aberrancy

• Assume V-T until proven otherwise
• Treatment for SVT can kill a patient in VT
• Treatment for VT usually wont kill a patient in
  SVT
• Criteria Brugada, others (beyond our scope)
• AV dissociation, increased age, CV risk factors
  VT
• Fusion / Dresler beats VT

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Wide, Fast Irregularly, Irregular WPW
(usually)
Special Treatment
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This patients resting EKG after you cardiovert
him
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Bradyarrythmias

• I. Pauses
• 1 cause of a pause is a non-conducted PAC
• II. Early, weird-looking beats
• PVC vs- PAC
• PVC
• Wide complex
• Compensatory pause
• PAC
• Narrow, no compensatory pause

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Bradyarrythmias

• I. Problem is sinus or at the AV node
• Sinus
• Sinus bradycardia
• Sinus Arrest
• AV Node
• 1st Degree AV block
• 2nd Degree
• Mobitz I (Wenkebach)
• Mobitz II
• 3rd Degree AVB

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• 2nd degree Mobitz I (Wenkebach)
• lengthening PR intervalthendropped beat
• Group Beating Wenkeback until proven
  otherwise
• Block at AV node
• Normal in young patients (high vagal tone)
• Think Meds (B-blockers, CCBs)

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• 2nd degree Mobitz II
• Constant PR intervalthen dropped beat
• Block always BELOW AV node (more serious)
• Never normal
• Likely needs a pacemaker

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• 3rd degree (complete) heart block
• A-V dissociation is present
• p waves march out
• Atrial rate gt ventricular rate
• Escape rhythm
• Clinical settings
• Likely needs a pacemaker

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Summary

• Follow the rules be systematic
• Tachycardia
• Narrow or Wide
• Regular or Irregular
• Bradycardia
• Mind your ps
• Know the basics
• Questions
• Now, lets do some examples