Transcript EKG Recognition for EMT’s

EKG
Recognition for
EMT’s (Part 2)
Scott S. Shadoin EMT-P
Boca Raton Fire Rescue
Boca Raton, Fl
Emergency Medical Consultants
Port St. Lucie, Fl
Professional Disclosures
• None
Objectives
• Discuss the anatomy of the heart
• Understand the components of an ECG
• Understand the following ECG’s
• Ventricular Rhythms
• AV Heart Blocks
• Pacemaker Rhythms
Cardiac Anatomy
• Myocardium
• Muscle of the heart
• Should contract when stimulated
• Atria
• Upper chambers of the heart
• Ventricles
• Lower chambers of the heart
Cardiac Anatomy
• Septum
• Separates left and right sides of atria and ventricles
• Cardiac Skeleton
• Separates the atria from the ventricles
• Impermeable to electricity
• Electrical conduction system
• Pathways through the heart for electricity
Electrical Conduction System
• Electricity created in Sinoatrial Node travels through
electrical system
• Myocardium contracts in response to stimulation
• Depolarization
• Change in cells electrical potential
• Muscle contracts in response
• Repolarization
• Cell resets to original electrical potential
• Muscle is relaxed
Electrical Conduction System
Electrical Conduction System
Electrical Conduction System
• Sinoatrial Node (SA Node)
• Pacemaker of the heart
• Sends electricity into atrium
• Bachmann’s Bundle (intra-atrial pathway)
• Delivers electricity to left atrium
• Atrioventricular node (AV Node)
• “Doorway” to ventricles
• Pauses electrical flow
Electrical Conduction System
Electrical Conduction System
• Bundle of His
• Splits in L/R bundle branches
• Connects AV node to Purkinje fibers
• Bundle branches
• Travel through ventricular septum
• Left bundle splits into anterior/posterior fascicle
• Purkinje fibers
• Disseminate electricity through the ventricles
Electrical Conduction System
EKG Paper
Left to right = TIME
-Small box = .04 sec
-Large box = .20 sec
-3 second ticks/marks
Up/down = DIRECTION
-Up = Positive
-Down = Negative
Height = VOLTAGE
-10 small boxes = 1mV
ECG Components
• P wave
• First part of the ECG complex
• Atrial depolarization
• QRS
• Usually largest voltage
• Ventricular depolarization
• T Wave
• Ventricular repolarization
ECG Pieces
• P waves
• Round (ish)
• Upright
• <.12 sec (3 small boxes wide)
• <.25 mv (2 ½ small boxes high)
ECG Pieces
• Q wave
• If it occurs, first negative deflection after the P wave
• Septal depolarization
• < .04 sec (1 box wide)
• < 1/3 total height of QRS
ECG Pieces
• R wave
• First positive deflection after the P wave
• Usually largest voltage on ECG
• Beginning phase of ventricular depolarization
• Entire QRS .04 - .12 sec (1 to 3 small boxes)
ECG Pieces
• S wave
• Return to baseline after R wave
• May be small or not present
• Late or ending of ventricular depolarization
ECG Pieces
• T wave
• Positive (usually) deflection after the QRS
• Ventricular repolarization
Electrode placement
Lead I
From Right arm to Left arm
Lead 2
From Right arm to Left leg
Lead 3
From Left arm to Left leg
*Lead 2 is the typical monitoring
lead
ECG Rules
1.
2.
3.
4.
5.
What is the rate?
Is it regular?
How do the P waves look?
PR Interval?
QRS width?
Interpretation?
Clinical Significance?
Rate?
• Ventricular Rate
• R to R
• 6 second rule
• Number of R waves in 6 seconds x10
• Triplicate method
• # of large boxes (5 small boxes) between R waves,
divide into 300
• 1 box = 300, 2 box = 150, 3 box =100, etc
Regular?
• Measure distances from R to R
• Can be slightly irregular with breathing, etc
P waves and PR Interval?
• Should be upright
• Consistent in shape
• QRS Relationship
• From start of P wave to QRS <.20 sec (5 small
boxes)
• P in front of every QRS (consistent PR interval)
• QRS after every P wave
QRS width?
• Narrow
• < .10 probably supraventricular (2 ½ small boxes)
• Wide
• >.12 Probably ventricular (3 small boxes)
Ventricular Rhythms
Ventricular Tachycardia
• Rate?
• >100
• Regular?
• Yes
• P waves?
• None
• PR Interval?
• None
• QRS?
• Wide >.12 sec
• Same shape
Ventricular Tachycardia
Torsades de Pointes
• Rate?
• >100/min
• Rhythm?
• No
• P waves?
• None
• PR Interval?
• None
• QRS width?
• Wide > .12 sec
• Polymorphic
• Electrical rotation
Torsdaes de Pointes
Ventricular Fibrillation
• Rate?
• Atrial: None
• Ventricular: Irregular and chaotic
• Regular?
• No
• P waves?
• None
• PR Interval?
• None
• QRS width?
• Wide >.12 sec
Ventricular Fibrillation
Coarse Fib
Fine Fib
Idioventricular
• Rate?
• < 40/min
• Regular?
• Yes
• P waves?
• None
• PR Interval?
• None
• QRS width?
• Wide > .12 sec
Idioventricular
Accelerated Idioventricular
• Rate?
• 40 – 100/min
• Regular?
• Yes
• P waves?
• None
• PR Interval?
• None
• Q waves?
• Wide > .12 sec
Accelerated Idioventricular
Agonal
• Rate?
• Atrial: None
• Ventricular <20/min
• Regular?
• Can be regular or irregular
• P waves?
• None
• PR Interval?
• None
• QRS width?
• Wide > .12 sec
Agonal
AV Heart Blocks
1° AV block
• Rate?
• Atrial: 60 – 100/min
• Ventricular: Same as atrial rate
• Regular?
• Yes
• P waves?
• Round, upright, uniform
• PR Interval?
• PR Interval >.20 sec
• QRS width?
• Narrow (M.B.W.W.A.C.)
1° AV block
2° AV block Type 1
(Wenckebach)
• Rate?
• Atrial: 40 – 60/min
• Ventricular: < Atrial rate
• Regular?
• No (P’s are, QRS’s are not)
• P waves?
• Upright, round, consistent
• P in front of every QRS
• QRS does not always follow every P
• PR Interval?
• PR Interval gets progressively longer
• QRS width?
• Narrow (M.B.W.W.A.C.)
2°Av block Type I
(Wenckebach)
2°AV Block Type II
• Rate?
• Atrial: 60 – 100/min
• Ventricular: < Atrial Rate
• Regular?
• Can be either (P’s are regular, QRS’s are not)
• P waves?
• Round, upright, consistent
• P in front of every QRS
• QRS does not follow every P
• PR Interval?
• PR Interval is always the same
• QRS width?
• Narrow (M.B.W.W.A.C.)
2° AV Block Type II
3°AV Block (CHB)
• Rate?
• Atrial: 60 – 100/min
• Ventricular: 20 – 60/min
• Regular?
• Yes, but no
• P to P is regular, R to R is regular (but not together)
• P waves?
• Round, upright, consistent
• P – QRS relationship nonexistent
• PR Interval?
• PR Interval is always varied
• QRS width?
• Usually wide
3°AV Block (CHB)
Pacemakers
Atrial Pacemaker
• Rate?
• Atrial: 60 – 100/min (ventricular follows atrial)
• Regular?
• Yes
• May be irregular if demand pacemaker
• P waves?
• Round, upright, consistent
• Small short pacemaker spike in front of P
• PR Interval?
• < .20 seconds
• QRS width?
• Narrow (M.B.W.W.A.C.)
Atrial Pacemaker
Ventricular Pacemaker
• Rate?
• Ventricular: 60 – 100/min
• Regular?
• Yes
• May be irregular if demand pacemaker
• P waves?
• None
• PR Interval?
• None
• QRS width?
• Wide
• Pacemaker spike in front of QRS
Ventricular Pacemaker
AV Sequential Pacemaker
• Rate?
• Atrial: 60 – 100/min
• Ventricular: Same
• Regular?
• Yes
• P waves?
• Round, upright, consistent (preceded by spike)
• PR Interval?
• PR Interval < .20 sec
• QRS width?
• Wide (preceded by a spike)
AV Sequential Pacemaker
Let’s Practice!
Ventricular Fibrillation
2°AV block (Wenckebach)
Torsades de Pointes
AV Sequential Pacemaker
3° AV block (CHB)
Ventricular Pacemaker
Ventricular Tachycardia
2° AV block Type II
Atrial Pacemaker
1° AV block
3° AV block (CHB)
In case you forget….
In case you forget…Part 2
In case you forget…Part 3
Scott S. Shadoin
[email protected]
Applause!!!
Psst!
You want a few more???
Premature Atrial Conctraction
(P.A.C.)
• An early firing of atria, causes ventricles to contract
• Identified by:
• An early complex (irregular rhythm)
• P wave looks different than rhythm
• If it is really early P wave may be hidden in
previous T wave
Premature Atrial Contraction
(P.A.C.)
Premature Junctional
Contraction (P.J.C.)
• An early firing of the AV Junction, causes ventricles to
contract
• Identified by:
• An early complex (irregular rhythm)
• P wave irregularity
• Missing, inverted, retrograde
Premature Junctional
Contraction (P.J.C.)
Premature Ventricular
Contraction (P.V.C.)
• An early firing of a cell within the ventricle, causing it to
contract
• Identified by:
• An early complex (irregular rhythm)
• Wide, bizarre QRS that does not resemble others in
the rhythm
• 1 – Complex
• 2 – Couplet
• 3 – Is a “RUN” or “SALVO” (considered V tach)
Premature Ventricular
Contraction (P.V.C.)
P.V.C.’s – Part Deux!
• Bigeminy – Every OTHER beat is PVC
• Trigeminy – Every THIRD beat is PVC
• Quadrageminy – Every FOURTH beat is PVC
P.V.C.’s – Part Deux!
Ok, that’s really it….
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