2330 EKG Rhythms

Normal Sinus Rhythm

• Vent. Rhythm = Reg
• Rate = 60-100
• P waves = (+), 1 QRS
• PR Interval = .12 - .20 (norm)
• QRS Duration = <.11 (norm)
• 

Sinus Bradycardia

• Vent. Rhythm = Reg
• Rate less than < 60 bpm
• P wave = (+), 1 P wave / QRS
• PR Interval = .12 - .20 (norm)
• QRS less than < .11
• 

Tachycardia

• Ven Rhythm = Reg
• Rate greater than > 100
• P wave = (+), 1 P wave/QRS
• PR Interval =.12 - .20
• QRS less than < .11 (norm)
• 

Sinus Arrhythmia

• Ven Rhythm = Irreg
• Rate = 60-100bpm
• P wave = (+), 1 P wave/QRS
• PR Interval =.12 - .20 (norm)
• QRS less than < .11 (norm)
• Reason: Autonomic nervous system causes small changes in HR associated with breathing
• Inspiration - Increased HR
• Expiration - Decreased HR
• Sympathetic Stimulation of SA Node (Increased Pacing) - Activated by Inspiration
• Parasympathetic Stimulation of SA Node (Inhibits Pacing) - Activated by Expiration
• Variability is normal.
• Reduced variability is pathological and indicates increased mortality, especially in heart disease or after infarction.
• 

Sinoatrial Block

• Ven Rhythm = Reg (Except for Event)
• Rate = Varies
• P wave = (+), 1 P wave/QRS
• PR Interval =.12 - .20 (norm)
• QRS less than < .11 (norm)
• Misc. = Same as distance between 2 P-P waves

Sinus Block (In Atria)

• Unhealthy SA node temporarily fails for at least 1 cycle
• -Missed beat has no P wave
• -SA node resumes at same rate as before block

AV Blocks: Slow / Block Impulse Completely

• 3 Types AV Blocks:
• 1st Degree AV Block: Lengthens delay between Atrial and Ventricular depolarization
• -PR Interval longer than .20 sec (1 big block) (Each cycle is long)
• 2nd Degree AV Block: Allow some Atrial depolarizations to conduct Vent. while others are blocked.
• -Result P wave with no QRS
• -PR interval is longer and longer and Drop
• 2 Types of 2nd Degree AV Blocks: @ AV node & Below AV node
• -

Slide 8

• 2nd Degree:
• Type I: Wenkebock

Slide 9

• 3rd Degree AV Block or Complete AV Block

Sinus Arrest

• Ven Rhythm = Reg (Except for Event)
• Rate = Varies
• P wave = (+), 1 P wave/QRS
• PR Interval =.12 - .20
• QRS less than < .11 (norm)
• Misc. = Not the same as distance between 2 P-P intervals
• # of big boxes between P-P interval after SA arrest is not divisible by # of big boxes between normal P-P interval

Premature Atrial Contraction (PAC's)

• Ven Rhythm = Reg (Except for Event)
• Rate = Varies on underlying rhythm
• P wave = Premature, (+), 1 precedes QRS, Differ from sinus P wave
• PR Interval = Normal or Prolonged
• QRS less than < .11 (norm)
• -The Irritable Focus fires early producing a unique P wave.
• -Next P wave is the SA REST

Wandering Atrial Pacemaker (WPM)

• Vent. Rhythm = Usually Irreg
• Rate = 60 - 100bpm
• P wave = Size/Shape/Direction may Vary
• PR Interval = Varies
• QRS less than < .11 (norm)
• Misc. = If rate is > 100 then called Multifocal Atrial Tach
• -Wandering = foci PPM wanders from one to another
• -Multifocal Atrial Tach = foci PPM fire at once

Multifocal Atrial Tachycardia (MAT)

• Vent Rhythm = Usually Irregular
• Rate = Over 100 bpm
• P waves = P wave shape varies
• PR Interval =
• QRS Complex =
• Misc. = MAT is Tachy but WAP (Wandering Atrial Pacemaker) is not Tachy
• Seen in pt with COPD. Atrial automaticity foci show early signs of parasystole (entrance block)

Atrial Tachycardia

• Rate = 150 -250 bpm
• P wave = P waves differ from Sinus P waves
• PR Interval = Shorter or Longer than Normal
• QRS less than < .11 (norm)

AVNRT (AV Nodal Re-entrant Tachy)

• Rate = 150 - 250 bpm
• P wave = P waves often hidden in QRS
• PR Interval = Normal IF seen (.12 - .20)
• QRS less than < .11 (norm)

Atrial Flutter

• Ven Rhythm = Reg/Irreg
• Rate = Variable
• P wave = Saw Tooth
• PR Interval = n/a
• QRS less than < .11 (norm)
• Only 1, 2 or 3 series of Flutter waves reach Vent.: Result is Vent. don't depolarize at same rate
• Identifying Atrial Flutter: Invert Tracing or Perform Vagal Maneuver

Atrial Fibrillation

• Ven Rhythm = Reg/Irreg
• Rate = Variable Rate
• P wave = F waves present, No discernible P waves
• PR Interval = n/a
• QRS less than < .11 (norm)
• Misc. = Uncontrolled: >100 bpm & Controlled: <100 bpm
• Cause: Rapid firing of multiple atrial automaticity foci suffering from entrance block pacing rapidly. (the atrial foci are parasystolic so they are all insensitive to overdrive suppression)
• -no single impulse depolarizes atria completely, and only occasional impulse reaches Vent.
• -Result: No P waves just erratic spikes,
• -Result: occasional impulse to Vent. may produce a rapid or slow Vent. rate, but is always Irregular

Woff-Parkinson White (WPW)

• Ven Rhythm = Reg (Unless a-fib present)
• Rate = 60-100 bpm if sinus is underlying
• P wave = (+), Normal (Unless a-fib)
• PR Interval less than < .12 if P waves are seen
• QRS > .12 usually
• Misc. = If PR interval > .12, then Delta wave may be seen (wide slurred QRS)
• 

Premature Junctional Contractions(PJC's)

• Ven Rhythm = Reg with premature beat
• Rate = Usually Normal
• P wave = Occur before, during, or after QRS. If BEFORE then INVERTED
• PR Interval = if present, <.12, if no P wave then n/a
• QRS less than < .11 (norm)

Junctional Escape Beat

• Ven Rhythm =
• Rate =
• P wave =
• PR Interval =.12 - .20
• QRS less than < .11 (norm)

Junctional Escape Rhythm

• Ven Rhythm =
• Rate =
• P wave =
• PR Interval =.12 - .20
• QRS less than < .11 (norm)

Accelerated Junctional Rhythm

• Ven Rhythm =
• Rate =
• P wave =
• PR Interval =.12 - .20
• QRS less than < .11 (norm)

Junctional Tachycardia

• Ven Rhythm =
• Rate =
• P wave =
• PR Interval =.12 - .20
• QRS less than < .11 (norm)

Premature Ventricular Contraction (PVC)

• Ven Rhythm =
• Rate =
• P wave =
• PR Interval =.12 - .20
• QRS less than < .11 (norm)
• R on T PVC: extra beat occurs on T wave of previous beat

Ventricular Escape Beat

Idioventricular Rhythm (IVR)

• Watchout may accually be Agonal rhythm

Slide 27

• Accelerated Junctional(s) - No P wave (What all have in common)
• Arrhythmia -
• Vent. Tach Know diff Vent. Fib - chaotic and not uniform
• Idoventricular - Slow rate
• Label EKG