Sinus Bradycardia (SB)
• Normal except HR<60

V-paced
Spike before the QRS

What’s the Difference Between Heart
Blockage
Clogged blood vessels
= i oxygen to the heart = heart attack
& Block?
Electricity blocked from traveling normally = arrhythmia

Idioventricular Rhythm
• Ventricular beats, but… at a slow rate
Your patient is
Going down the
Drain if he stays
In this rhythm very
Long!

Pulseless Electrical Activity (PEA)
• Normal rhythm, but…
* No Pulse*
Gabriel is blowing his horn!!
Call Code!

Mobitz I: Wenkebach
• PR interval gradually longer until a QRS is dropped
• Pattern repeats normal longer longer dropped QRS

Bigeminy
Every second beat is a PVC
Geminy
Cricket!

Atrial Fibrillation (Afib)
• Irregular
• No definable P waves unable to count the # of waves

Premature Ventricular Contraction
(PVC)
•Early ventricular beat

Heart Rate:
PR Interval:
QRS Interval:
Normal Values
60-100 beats per minute
.12-.20 seconds
< .11 seconds

Failure to Capture
• Pacer spike is fired, but no beat follows

Mobitz II
• PR interval consistent except some QRS missing
Blocked QRS
Example PR intervals: .16 – B - .16 – B - .16 - .16 - B

Normal Sinus Rhythm (NSR)
• Rhythm is normal
• Rate normal 60-100
• PR normal .12-.20
• QRS normal < .11

Junctional Rhythm
• No P wave or PR < .12

Pause
• Period of no electrical activity, then resumes

Paroxysmal Atrial Tachycardia (PAT)
• Sudden rate change > 150 bpm
• QRS shape is similar before & after rate change
QRS look similar in shape

1 º AVB
PR interval >.20
PR intervals:
.24 - .24 - .24 - .24 - .24

Sinus Tachycardia (ST)
• Normal except HR >100 bpm

Ventricular Tachycardia (VT)
• Ventricular beats (wide QRS’s)
• Rate > 150 bpm
Call Code!

Sinus Arrhythmia (SA)
• Normal except irregular

Asystole
• No electrical activity
Call Code!
My heart may stop if
This guy was swimming
With me!!!

Trigeminy
Every 3rd beat is a PVC

3rd Degree AV Block (3º AVB)
Atria & ventricles act independently
• Regular P waves
• Regular QRS complexes
But…P waves and QRS not working together
• PR interval varies (but not in Wenkebach pattern)
• Harmful -- patient needs a pacemaker soon!
blocked normal blocked blocked short blocked normal blocked
Example PR intervals: .14 – B - .20 – B – B - .12 – B - .44 - .32 - B

Torsades de Pointes
• A form of VTach which looks like the rhythm strip is twisting
Call CODE!

Steps to Interpret Rhythms
1. Are the beats at regular or irregular intervals apart?
2. Do you see P, QRS, T pattern?
3. What is the HEART RATE ?
4. What is the PR interval?
SINUS
ATRIAL
JUNCTIONAL
VENTRICULAR
5. What is the QRS interval?

A-paced
A spike before the P wave site

Mobitz II
 PR regular except some QRS are dropped
PR intervals:
.12 – B - .12 - .12 – B - .12 – B
QRS

Atrial Flutter
• Numerous P waves that you can count

Premature Beats
P V C
P J C
P A C
Wide QRS
PR<.12
PR=.12-.20

Wenkebach
PR gradually longer until QRS dropped
PR intervals:
.12 - .18 - .24 – B - .12 - .18 - .24 – B

Ventricular Fibrillation (VF)
• Squiggly line
Call CODE!

Failure to Sense
• Heart is beating just fine, but pacemaker fires anyway
• Spikes are not in a consistent place before P or QRS
--seen in many different places

ST Elevation
QRS exits higher than it starts enters exits

Wandering Atrial Pacemaker (WAP)
• P waves vary in shape
(at least 3 different P waves)

3º AVB
PR interval varies, but not in Wenkebach pattern
PR intervals:
.12 – B - .20 – B – B - .16 - .44 – B - .32

Premature Beats
3 Types
Premature Atrial Contraction (PAC)
Premature Junctional Contraction (PJC)
Premature Ventricular Contraction (PVC)

Bundle Branch Blocks (BBB)
QRS >.11

AV-paced
Spikes before the P wave site & QRS

Premature Junctional Contraction (P J C)
• Early beat
• No P wave or PR interval is <.12

First Degree AV Block
(1º AVB)
• PR interval > .20
A // V
Example PR intervals: .28 - .28 - .28 - .28 - .28 - .28

ST Depression
QRS exits lower than it starts enters exits

Paroxysmal Supraventricular Tachycardia
(PSVT)
• Sudden rate change >150 bpm
• QRS may look different after rate change
QRS look different in shape

Types of AV Blocks
•
First Degree
•Second Degree
1°AVB
Wenkebach
Mobitz II
•
Third Degree 3°AVB

Premature Atrial Contraction (P A C)
• Early beat
• Normal PR interval
The alarm clock
Always goes off
PREMATURELY!!

• VT
• VFib
• Asystole
• Torsades
• PEA