Application and Dysrhythmia Interpretation

Jan Hovekamp, RN, Clinical Educator for Telemetry Services

St. Joseph Healthcare 2008
 Cardiac Rhythm & Dysrhythmias
I. Anatomy and Physiology of the Heart Atrial
II. What is an EKG? 1. Atrial Fibrillation (A-Fib)
III. Stages of the Heart Beat & How we measure them 2. Atrial Flutter (A-Fl)
IV. Steps to Interpret Rhythms 3. Wandering Atrial Pacemaker (WAP)
V. Dysrhythmia Groups 4. Paroxysmal Atrial Tachycardia (PAT)
Sinus 5. Paroxysmal Supraventricular Tachycardia (PSVT)
1. Normal Sinus Rhythm (NSR) Other Wave Changes
2. Sinus Tachycardia (ST) 1. ST Elevation
3. Sinus Bradycardia (SB) 2. ST Depression
4. Sinus Arrhythmia (SA) 3. Tall T Waves
5. Sinus Arrest – Asystole 4. Inverted T Waves
6. Pause 5. Tall P Waves
7. Pulseless Electrical Activity (PEA) 6. Inverted P Waves
Junctional Heart Blocks
Premature Beats 1.Bundle Branch Block (BBB)
1. Premature Atrial Contraction (PAC) 2.AV Blocks (Atrial-Ventricular Block
2. Premature Junctional Contraction (PJC) First Degree AV Block
3. Premature Ventricular Contraction (PVC) Second Degree AV Block–Type 1 – Wenckebach
a. PVC Second Degree AV Block–Type 2 – Mobitz II
b. Couplet Third Degree – Complete Heart Block
c. Triplet
` d. Bigeminy
e. Trigeminy
Ventricular
Regions of
1. Ventricular Tachycardia the Heart
2. Sustained V Tach
3. Idioventricular Sinus
4. Torsades de Pointes
5. Ventricular Fibrillation Atrial
Pacemakers
1.Failure to Capture Junctional
2.Failure to Sense
3.Atrial Paced
4.Ventricular Paced Ventricular
5.AV Paced
http://www.smm.org/heart/heart/circ.htm
 Section 1

The heart is made up of four

chambers

Left Atrium

Right Atrium
Left Ventricle

Right Ventricle
 The first part of the heartbeat

Oxygen-rich
blood from
lungs fills left
atrium

Oxygen-poor
blood from
the body fills
right atrium
 Then both Atria Contract
Pushing all the blood into the left and right Ventricles
They usually contract at the same time

Left
Right Atrium
Atrium
Left
Right Ventricle
Ventricle
 The Second Part of the Heartbeat
The Ventricles Contract, occurs at about the same time:

The Left side

The Right Ventricle
Sends oxygen
Sends blood
Rich blood
through the
through the
Pulmonary Artery
Aorta to
To the Lungs to
The body
pick up Oxygen

Send

The combination of the 1st and 2nd part of the heartbeat Creates the Lub-Dub,
the first and second sounds of the heart beat
http://www.apexinnovate.com/impulse_demo/impulse_v3.swf
 What makes the heart pump?
Natural Electric Impulses
Which stimulate heart muscle to contract
• The heart is made primarily of muscle
• When the muscle contracts, it squeezes the blood
through the heart and out to the lungs or to the body
 Where does the Electricity Come From?
Pacemakers
The heart has natural
power generators that
tell the heart to pump.
The primary pacemaker is the SA Node
Located in the top of the Right Atrium

The AV node is located in the junction *

Of both Atria and both Ventricles

* Secondary pacemakers * *
are scattered throughout the
heart *
They function as a lifesaving
backup if the SA node fails, though
sometimes they malfunction
*
*
 How Electricity Travels…

Electrical Conduction
Pathway
“Power lines” quickly carry
electrical impulses from the
pacemakers throughout the
heart
 What Electricity Does…
Myocardium-one of
three layers of the heart.
Muscle cells which make up
the bulk of the heart. They
are able to generate or pass
on electricity.
Electricity that originated at
the pacemaker cells, now
waves across the muscle
cells, causing them to
contract which pumps the
blood through the heart.
http://hybridmedicalanimation.com/anim_heart.html
 This is the normal pathway for electricity
to travel through the heart

SA node

AV node

Bundle of His

•Left bundle branch

•Right bundle branch

=
Myocardium
contracts
 When we lose power!
SA Node (inherent rate of 60 – 100)

When the hospitals in New

Orleans lost power after
Katrina, they progressed
Atrial foci (inherent rate of 60 – 80)
down the different levels of
functioning. At first they
could still function but not
Junctional foci (inherent rate of 40 – 60)
as well as they could with
full power. The further down
the power source went, they
Ventricular foci (inherent rate of 20 – 40)
were not as efficient or as
effective as the previous
level.

Each area can

The lower the level in the heart, where the foci is pace, but not as
located that is doing the pacing, the lower is the well as the area
“inherent rate” (heart rate) produced by that above it!
area). A foci is a potential pacemaker (or cell)
that is capable of pacing in emergency situations.
Decoding a Rhythm Strip
 Section 2

What Is An EKG?
• A graphic representation of the electrical
activity of the heart

As electricity travels across the heart, it causes the cells to shorten, which
causes the heart to beat !
This propels the blood through the heart and out to the lungs or to the body !
The Electrical Basis of the EKG
Electrical impulses are present
on the skin surface at a very
low voltage; The EKG
machine picks up these PR Interval QT Interval
impulses and amplifies them.
Electrical activity is sensed by
Electrodes are placed on
the skin surface to pick up
these impulses and give us a
picture of how they are
traveling in the form of an
QRS Interval
Electrocardiogram. This is
printed on EKG paper and is
called a Rhythm strip or an
EKG strip
 These lines represent the electricity
traveling over specific parts of the heart
 Stages of the Heartbeat:
QRS

P T
wave wave

Atria Ventricles
contract relax

Ventricles
contract
P Wave, QRS & T Wave make up one complete CARDIAC CYCLE
 Breaking down the QRS complex

R wave
Q
wave

S wave

There may be 3, 2 or only 1 part of the QRS present. It is still called a QRS!
To know if the heart is healthy, we
measure the size of these waves
How We Measure:
EKG Paper
As the paper prints out……
we are measuring time…….

Duration (Time)
Measured in Seconds
• EKG paper is divided
into small squares and
larger squares

• Large squares are 0.04

Seconds
defined by a dark line.
They are 5 squares high
and 5 squares long
(0.20 seconds)

• Small squares may be

lines or may be dots
within the dark lines.
They are 0.04 seconds
0.20 Seconds
What We Measure
• Heart rate
• PR interval
• QRS interval
May be done In ICU’s and if
• QT Interval patient is on certain medications
(i.e. Tikosyn)
 Heart Rate: The Easy Way

Look for marks below EKG grid

Every mark is 3 seconds
(2 marks = 6 seconds)

Count the # of beats by 10’s (10-20-30-40…)

On a 6 second strip
HR for example above = 80 bpm
Intervals We Measure
R QT interval

P T
Q S

PR
Interval
QRS
Interval
 Artifact
• EKG waveforms from sources outside the heart
• Interference seen on a monitor or EKG strip
– 4 causes
• Patient movement (i.e. pt. with tremors)
• Loose or defective electrodes (fuzzy baseline)
• Improper grounding (60 cycle interference)
• Faulty EKG apparatus
When two cars are traveling a distance at the same
miles per hour, the one with the shorter distance will
arrive at their destination first. Likewise, it takes a
certain amount of time for electricity to travel to a
destination in the heart. By measuring these distances
and how long it takes to travel, we get a picture of what
is going on in the heart.
An easy method to measure the different waveforms is a ruler (If you do
not have one, see your clinical educator). Other methods include using
calipers, memorizing charts, using tables or even a scrap piece of paper.

Match up the lines!

The clear spaces are Don’t place over the
used for measuring rhythm strip.

.04 .06 .08 .10 .12 .14 .16 .18 .20 .22 .24 .26 .28 .30 .32 .34 .36
PR Junctional / PJC Normal PR / PAC 1st Degree AVB -->
QRS Normal QRS BBB wide QRS blending into T wave = Ventricular beat / PVC
STEPS: CHART QUALITY STRIPS! RUN STRIPS for:
Regular?
P, QRS, T pattern?Saint Joseph CVTs Pt label & name match Within 1 hr of 8-12-4
Document if pt off unit Admit or transfer
HR? Tracing within graph lines Rhythm changes
PR?
QRS?
Measure Up! No folded strips Invasive procedures:
Don't exceed page width (OR, cath lab, endo)
Wenkebach Mobitz II 3rd Degree AVB
.12-.20-.28-B-.12-.20-.28-B .20-B-.20-.20-B-.20-B-B .32-B-.24-.16-B-B-.44-B-.20-B
 PR

12 .14 .16 .18 .20

Normal PR / PAC
BBB
 QRS

.04 .06 .08 .10 .

PR Junctional / PJC
QRS Normal QRS
 Steps to Interpret Rhythms
Normal Values

Heart Rate: 60-100 beats per minute

PR Interval: .12-.20 seconds

QRS Interval: < .11 seconds

1. Are the beats at regular or irregular intervals apart?

2. Do you see P, QRS, T pattern?

3. What is the HEART RATE? SINUS

4. What is the PR INTERVAL?
ATRIA
LJUNCTIO
NAL
5. What is the QRS INTERVAL?
VENTRICU
LAR
 Origin of Rhythms
They are named for the structure of the heart where the
foci (a cell sending off an electrical impulse) is located
that is producing the abnormal rhythm

• Sinus (Sinus node)

• Junctional (Area between the
atria & ventricles)
• Ventricular (any cell in the
ventricles)
• Atrial (any cell in the atria)
• AV Blocks (AV node blocking
some or all of the passage of
electricity through it)
Regions
of the
Heart
Sinus
Atrial

Junctional

Ventricular
 Normal Sinus Rhythm (NSR)

The SA node has generated an impulse that followed the

normal pathway of the electrical conduction system
• Rate normal 60-100
• PR normal .12-.20
• QRS normal < .11
Sinus Bradycardia (SB)
• Everything measures normal
except the HR is less than 60
Sinus Tachycardia (ST)
• Normal except HR >100 bpm
 Sinus Arrhythmia (SA)
Normal except irregular
The difference between the fastest two heart
beats (from 1 QRS to the next QRS) and the
slowest two heart beats is greater than .12 sec
 Asystole
No electrical
activity
Code Blue
 Pause

Period of no electrical activity, then

electrical activity resumes
 Pulseless Electrical Activity (PEA)
Normal rhythm, but…No Pulse*
Electrical activity is present but there is no pulse, so
the heart is not beating! Something has happened
to prevent the muscular tissue from responding to the
electrical activity
(i.e. ↓↑ K+, hypothermia, Pneumothorax, cardiac tampanode,
hypovolemia, drug overdose, pulmonary or coronary thrombosis)

Code BLUE!
Rhythms arising from the SA Node
• Sinus Rhythm

• Sinus Tachycardia

• Sinus Bradycardia

• Sinus Arrhythmia

• Asystole

• Pulseless Electrical Activity

Regions
of the
Heart
Sinus

Atrial

Junctional

Ventricular
 Sinus
PR Interval will
be normal

Junctional
PR Interval will be
Less than normal

Or…
There will
Be no P Wave
 Junctional Rhythm

No P

or

PR< .12
Regions
of the
Heart
Sinus

Atrial

Junctional

Ventricular
 Sinus
Atrial

Junctional

Ventricular
 Sinus Rhythm

Junctional Rhythm

Ventricular Rhythm
 Sinus
Atrial
PR = .12-.20

Junctional
PR < .12

Ventricular
Wide
QRS
 Premature Beats
• Not a rhythm, just a single early beat

Three Options:
•If it arises from the Atria, it will have a normal PR Interval
This is a Premature Atrial Contraction or PAC
•If it arises from the Junctional area, it will have a PR Interval
which is less than normal or no P wave at all
This is a Premature Junctional Contraction or PJC
•If it arises from the Ventricular area, it will be a QRS which is
wide and bizarre shaped
This is a Premature Ventricular Contraction or PVC
 No P
Wave

SR w/ PJC
P Wave
Close to
QRS

SR w/ PJC
A wide
bizarre
QRS

Junctional Rhythm w/ PVC

Sinus Rhythm

SR w/ PAC
Junctional Rhythm

SR w/ PJC
Ventricular Rhythm

SR w/ PVC
Ventricular Arrhythmias
 When are PVCs a Problem?
– Increase from the patient’s normal amount
– Multiple PVCs in a row
– PVC falls on the T wave of previous beat
– Multifocal (they arise from different cells, therefore they are
different shapes)

Multifocal PVCs
 PVC Troubles
Bigeminy = every other beat is a PVC

Trigeminy = every 3rd beat is a PVC

Multiple PVCs
Couplet

Triplet
 Ventricular Tachycardia (VT)
• 4 or more ventricular beats in a row
• Rate > 150 bpm
If you step on
A Tack, you will
Get off of it fast!

6 beats of VTach
 Sustained VTach

Pt stays in VTach & needs our help to

switch (defibrillate or cardiovert)
Code BLUE !
Idioventricular Rhythm
• Ventricular beats, but….
slow rate
 Torsades de Pointes

A form of VTach which looks like the rhythm

strip is twisting
Code BLUE !
Ventricular Fibrillation (VF)

• Squiggly line
• Code BLUE !
 VENTRICULAR BEATS REVIEW
1 Ventricular Beat = PVC
2 Beats = Couplet
3 Beats = Triplet
More than 3 beats at fast rate = V Tach
Ventricular beats at slow rate = Idioventricular
Ventricular beats twisting tall-short-tall = Torsades
No QRS, just shaking = V Fib
Every second beat is ventricular = Bigeminy
Every third beat = Trigeminy
Pacemakers
 Pacemaker Changes on EKG
* You must select pacemaker mode on the monitor
A straight pacemaker “spike” will appear
A spike before the P wave site is “A-paced”
before the QRS is “V-paced”
before both is “AV-paced”
A-paced V-paced
Pacemaker Troubles

“What Can Go Wrong?”

 Failure to Capture

• Pacer spike is fired, but no beat follows

You can have QRS’s without pacer spikes, but you cannot have pacer
Spikes without a QRS following it!
 Failure to Sense
• Heart is beating just fine, but pacemaker fires anyway. The
pacemaker should sense what the heart is doing on its own so it
doesn’t send out an electrical stimulus at a time when the heart
is more vulnerable
• Spikes are not in a consistent place before P or QRS
--they are seen in many different places
Regions
of the
Heart
Sinus

Atrial

Junctional

Ventricular
 Atrial Flutter
Can count the # of flutter waves (P waves)

Atrial Fibrillation (Afib)

Unable to count the # of waves
 Wandering Atrial Pacemaker

Atrial pacemakers *

*
*
Different pacemakers fire in a row.
Since they come from different
areas in the atria, they will be
shaped differently on the strip
 Wandering Atrial Pacemaker
(WAP)
• P waves vary in shape (at least 3 different P waves)
• They are coming from different areas of the Atria so
they may have different PR Intervals, also
 Sudden rate change > 150 bpm
Paroxysmal Atrial Tachycardia (PAT)

Paroxysmal Supraventricular
Tachycardia (PSVT)
Cannot distinguish a P wave after the HR gets fast
 Atrial Rhythms Review
• Atrial Flutter
• Atrial Fibrillation

• Wandering Atrial Pacemaker

• Paroxysmal Atrial Tachycardia

• Paroxysmal Supraventricular Tachycardia
 Early Indications that a
heart is having difficulty!
ST Changes: Heart Attack in Progress
R

P T
The QRS should enter & exit on the baseline Q S

ST Depression (Ischemia) ST segment

(QRS exits lower than it starts)
enters
exits

ST Elevation (Infarction)
(QRS exits higher than it starts)
exits
enters
 ST Elevation

I would probably
have a heart attack if I
had to climb this!

ST Depression

He sure is down
and depressed !
 Other Wave Changes
• Tall T waves
• Inverted T waves (upside-down)

• Tall P waves
• Inverted P waves
Hello
™Only inverted P waves are normal
Only 1 group of arrhythmias to go!
I feel like
I am on a
treadmill
!
Heart Blocks
 What’s the Difference Between Heart
Blockage & Block?
Clogged blood vessels = Electricity blocked from
decrease in oxygen to the traveling normally =
heart = heart attack dysrhythmia

Plumbing ! Electricity !
 Bundle Branch Blocks (BBB)
It takes longer for electricity
to travel around the blockade
to contract the ventricles.

Takes longer for

ventricles to contract

This shows as
a wide QRS
≥ .12 Left BBB
You are trying to get to Lexington from Berea. There is a
Wreck on the Clays Ferry Bridge and the bridge will be
Shut down indefinitely. You can still get to Lexington, you
Will just have to go a different route, which will take longer.
 Atrial Ventricular Heart Blocks
The AV Node acts as the gatekeeper for the ventricles, holding the electrical
impulse a brief interval to make sure the Atria have finished contracting thus
expelling all the blood into the ventricles before allowing the ventricles to
contract.

•Electricity contracts
atria first, then travels
down to contract the
ventricles.
•If the electricity is
blocked between the
atria & ventricles, the
travel time (PR) is
abnormal.
•Hence, AV blocks have
an abnormal PR
interval.
 Types of AV Blocks
lightest
First Degree 1°AVB

Wenckebach/Mobitz I
Second Degree
Mobitz II

Third Degree 3°AVB

worst
 First Degree AV Block
(1º AVB)
• PR interval > .20
A // V

Example PR intervals: .28 - .28 - .28 - .28 - .28 - .28

 Mobitz I: Wenkebach
• PR interval gradually longer until a QRS is dropped
“B” indicates a Blocked Beat
• Pattern is repeated
• Typically not harmful
normal longer longer dropped QRS

Example PR intervals: .14 - .20 - .32 – B - .14 - .20 – 32 - B

 Mobitz II
• PR interval consistent except some QRS missing
• Harmful--may indicate serious heart disease or
progress to 3rd degree block
Blocked QRS

Example PR intervals: .16 – B - .16 – B - .16 - .16 - B

 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 blocked normal blocked
short

Example PR intervals: .14 – B - .20 – B – B - .12 – B - .44 - .32 - B

 Wenckebach Theme Song

• http://www.youtube.com/watch?v=GVxJ
J2DBPiQ
 Block Review
Bundle Branch Blocks QRS > .11

1 º AVB .24 - .24 - .24 - .24 - .24

¾ PR interval >.20

Wenkebach .12 - .18 - .24 – B - .12 - .18 - .24 – B

¾ PR gradually longer until QRS dropped

Mobitz II .12 – B - .12 - .12 – B - .12 – B

¾ PR regular except some QRS are dropped

3º AVB .12 – B - .20 – B – B - .16 - .44 – B - .32

¾ PR interval varies, but not in Wenkebach pattern
 Heart Block Review
Other Name PR Interval Characteristic
1st ˚AV Block Same PR Interval > .20

2nd ˚AV Block Wenkebach or Different PR Interval gets longer

Mobitz I until 1 is dropped
2nd ˚AV Block Mobitz II Same PR Interval is the same
when you can measure it,
some p waves do not
have a QRS after it so you
can’t measure a PR
Interval for all
3rd ˚AV Block Different PR Interval varies but not
in any pattern, P waves
and QRS waves are not in
any relationship to each
other

Bundle Branch Block = QRS is > .11

PR Interval
PR Interval’s are the same- it will either be Degree AVB (QRS for every P) or Mobitz II (May or may not have QRS for every P)
1st
PR Interval’s vary – it will either be Wenkebach (pattern) or 3rd Degree AVB (no pattern)
Which rhythms are a
CODE Blue?
• VT
• VFib
• Asystole
• Torsades
• PEA
Performing a 12 Lead EKG
 12 Lead (views) of the Heart
Lateral leads

AVR AVL

V6
I

V5
V1
V2
V3 V4
III II
AVF
Anterior leads
Inferior leads
 Skin Prep:
For quality EKGs

You need good contact between the skin & electrode

• Hair interferes with the EKG reading--shave if needed!

• Rub with alcohol to remove body oil
• Rub with a dry 2×2 gauze to remove old skin cells
 Chest Leads

V1 & V2 in the 4th rib space (barely above the nipple to each side of the sternum—
not on the sternum!
V4 in line with mid-collarbone
V6 in line w/ mid-underarm
V3 will go halfway between V2 & V4
V5 in line w/ underarm front, halfway between V4 & V6
 Limb Lead Placement

Limb leads can

be placed RA LA
anywhere on the
limbs and still
get the same Vb
reading but, Va
AVOID BONY
AREAS!
RL LL
• Verify the EKG is ordered & you have the correct patient
• Explain to the patient what you are doing
• Ask patient to lie down
• Maintain privacy (close door, pull curtain, uncover minimally)
• Prep skin, attach electrodes & wires
• If pacemaker is to be turned off, RN must turn it off and RN
must remain in the room until pacemaker is back on.
• Ask the patient not to move
• Wait for tracings to stabilize
• Press “Record EKG”
• Verify patient name, room #, and quality tracing
• Detach electrodes & wires
• Place EKG on chart or give to requesting MD
 If ordered stat, do it right
away! Rhythms can change
in a matter of minutes !
A patient could code at any time…
so be prepared—
100% Quality Monitoring
100% of the Time
 Top 3 Absolutes!
#1—Change batteries
#2—Fix loose electrodes (leads)
#3—Ensure all patients are on the monitor
– Make sure staff call you before removing transmitters
– Place a location label on patients off the unit
– Re-attach the transmitters when patients return
– Re-engage alarms by removing “off unit” label

Patients have died when alarms were off & arrhythmias unnoticed
 Transmitters
• Only use a transmitter that is assigned to your specific pt’s room
– If transmitter is broken or missing, use a spare
– Do NOT allow staff to use transmitter from another room
– Call the House Administrator if additional spares needed
• ALWAYS double-check transmitter # before using
• Insist staff return transmitters immediately upon discharge!
• Inventory transmitters & track missing equipment ASAP
• Notify UM of broken or missing equipment (repairs by Bio-med)
• Clean transmitters & wires between patients (wear gloves)

Make sure staff place soiled transmitters in soiled bin—not on your desk!
Patients who are at greater risk of
developing Cardiac problems:
–New patients
–Confused patients (often pull off
their monitor)
–Recent or current procedure
–Recent EKG change or risky rhythm
 Troubleshooting
If the heart rhythm is not transmitting correctly:
• Check the electrodes & change if necessary
• Change the battery
• Try a different transmitter box
• Try a different set of lead wires
If still no success:
• Use a spare transmitter & notify Bio-Med
 Documentation
•Run strips every 4 hours (8-12-4)
*Strips must be run within 1 hour of above times
•Measure & interpret the 8 o’clock strips & have nurse sign
•Also run strips:
–Upon admission or transfer
–After invasive procedures (cath lab, OR, endoscopy)
–New or risky rhythms
• If a patient is off the unit when you run strips,
– document where the pt is on the strip
– leave yourself a note to run a strip when they return
 Charting Strips
•No poor quality strips in the chart—run another strip
•Cut strips so the name, room #, and time are displayed
•Strips must be 6 seconds in length, but not exceed page width
•Do not fold strips. Cut & write “continuous” on the strip
•Place first strip at bottom of the page, and work upward
•Verify the pt labels match when placing strip on the chart!
•Make sure rhythm is not outside grid lines (too tall or small)
•Do not write over the rhythm tracing
•Don’t tape over writing or rhythm. Use double-stick tape.
 Patient Confidentiality
Protect privacy...Please do not look up rhythms or info
on patients you (or others) are not treating
(This includes yourself, family, & friends)

Don’t risk it--People have been terminated for this!

YOU MADE IT!

Congratulations ! ! !
 Now……
Study….Study….Study

Dysrhythmia’s