EKG’s Kelly Marchant RN July 28, 2015 Adapted from NURO 438 Cardiac Dysrhythmias.
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Transcript of EKG’s Kelly Marchant RN July 28, 2015 Adapted from NURO 438 Cardiac Dysrhythmias.
EKG’sKelly Marchant RNJuly 28, 2015Adapted from NURO 438Cardiac Dysrhythmias
Learning ObjectivesAt the completion of this presentation, the learner will be able to successfully…
Review Cardiac Anatomy & Physiology, including function, circulation & automaticity
Describe & Define waves on an EKG
Define & Identify Normal SR
Analyze EKG rhythm strips
Review
Cardiac Anatomy
Cardiac Anatomy4 Chambers, 2 Atria, 2 Ventricles
4 Valves
Acts as a PUMP
Receives deoxygenated blood from body, umps to lungs
Receives oxygenated blood from lungs, pumps to body
Cardiac Circulation
Automaticity
Impulse GenerationUnder Usual circumstances
Impulse generated from pacemaker cells in SA node
Impulse then travels to AV node
Impulse then travels to Bundle of His
Impulse then travels to Right and Left Bundle Branches
Impulse travels to Perkinje Cells that innervate ventricles
The EKG
EKG Graph
X Axis = time Y Axis = amplitude
Displays electrical activity of heart
Electrical impulse precedes contraction
Depolarization and repolarization are depicted as waves Atrial Depolarization = P wave Atrial repolarization occurs during ventricular
depolarization Ventricular depolarization = QRS complex Ventricular repolarization = T wave
Telemetry Placement
Red = Brake (right), Green = Gas (left)
Smoke (black) over Fire (red), Snow (white) on the Trees (green)
Stars and Stripes
EKG BasicsMeasures electrical potential between the
electrodes
AKA ‘Standard Limb Leads’
Leads I,II,III
Used to monitor only for dysrhythmias
Lead II most commonly used
Lead II
Cardiac Waves
The P Wave SA node is pacemaker,
Impulse begins in SA node moves R-> L, and down
Rate 60 – 100
Precedes atrial depolarization
PR interval 0.12-0.2 sec
Determines atrial rate
Irregular P wave Afib/flutter PAC SVT AV Block
The QRS Complex Represents normal
depolarization of the ventricles
Normal duration 0.06- 0.12 sec
Measured from Q wave (first deviation from isoelectric line) to S wave (the return to isoelectric line)
Abnormal QRS is abnormal depolarization PVC (wide bizarre QRS) BBB (prolonged QRS) Ventricular pre-excitation Cardiac pacemaker
The T wave
Represents Ventricular repolarization
Occurs during end of ventricular systole
Typically in same direction as QRS complex
Lasts 0.10 – 0.25 sec
Irregularities most often caused by pharmacology
The U WaveFinal stage of
repolarization, thought to be repolarization of Perkinje Fibers
Not usually seen
May indicate HypokalemiaCardiomyopathyLVHDig toxicity
Wave Matching1. Ventricular
Depolarization
2. Irregular Ventricular Beat
3. Atrial Depolarization
4. 0.12-0.20
5. Ventricular Repolarization
6. Wide, bizarre QRS complex
7. Early atrial beat
8. Pacemaker site
9. 0.06-0.12
10. Sets Normal Heart Rate
A. AV Node
B. T wave
C. PAC
D. SA Node
E. PVC
F. P wave
G. QRS Complex
EKG Paper
At the 25 mm speed, Each mark at top is 3 secondsThere are three large boxes between each markEach large box is 1 second or 25 mmEach large box has 5 medium boxes in itEach medium box is 0.2 seconds or 5 mmEach medium box is made up of 5 small boxes (or dots)Each small box (dot) = 0.04 seconds or 1 mm
EKG Paper
Steps to Interpreting Cardiac RhythmsDetermine the Heart Rate
Determine the Regularity
Identify and analyze P waves
Determine PR interval and AV conduction
Identify and analyze QRS complex
Determine site of origin of dysrhythmia
Identify dysrhythmia
Evaluate significance of dysrhythmia
Determine the Heart Rate The Six-second Method
Most common/least accurate Simplest, quickest
Heart Rate Calculator
The Rule of 300 Must be regular
R-R Interval Method Rhythm must be regular Distance between peaks of 2
R waves and /60
Describe the Rate & RhythmNormal = 60-100
Tachycardia >100
Bradycardia <60
Regular
Irregular
Regularly-irregular
Sinus ArrhythmiasSB = HR < 60
ST = HR >100
Steps to Interpreting Cardiac RhythmsDetermine the Heart Rate
Determine the Regularity
Identify and analyze P waves compare to QRS
Determine PR interval and AV conduction
Identify and analyze QRS complex
Determine site of origin of dysrhythmia
Identify dysrhythmia
Evaluate significance of dysrhythmia
Measuring the Waves
PR Interval Represents progression of electrical
impulse from the SA node or an ectopic pacemaker (in atria or AV junction) through entire conduction system of the heart to the ventricular myocardium
Normal duration 0.12 – 0.20
Irregular P waves demonstrate changes in atrial function (Afib/flutter, SVT, PAC)
PR >0.20 represents delayed conduction of impulse (AVB)
PAC’s Premature Atrial Contraction
P wave followed by normal QRS
Generally followed by noncompensatory pause
P waves vary, PR intervals normal
AV Ratio 1:1 Conduction
QRS ComplexRepresents normal
depolarization of the ventricles
Onset is point where first wave (Q) deviates from isoelectric line
End is where last wave (S) returns to isoelectric line
Duration 0.06 – 0.12
Irregular QRS complex correlate with changes in ventricular function (PVC, Vtach, Vfib)
QT IntervalRepresents time it takes for
ventricles to depolarize and repolarize
Prolonged QT associated with pericarditis, myocarditis, MI, LVH, hypothermia, CVA, increased IC trauma or hemorrhage, medication SE, electrolyte imbalances (K, Ca), or liquid protein diets
Irregular QRSRepresents
abnormal depolarization of ventricles
Irregular QRS present in Bundle Branch Block Ventricular
preexcitation Cardiac pacemaker
Single PVC
Apply the Eight Steps
Apply the Eight Steps
Apply the Eight Steps
Take Home PointsEKG is measurement of ELECTRICAL activity
Electrical activity precedes mechanical activity
Use the 8 Step Method
Identifying Normal Rhythms will enable you to identify Irregular Rhythms
Changes in atrial function displayed as irregular P wave (Afib/flutter, PAC, AVB)
Changes in ventricular function displayed as changes in QRS complex (PVC, BBB)
Living Arrythmias
https://www.youtube.com/watch?v=TJR2AfxVHsM
References
http://lifeinthefastlane.com/ecg-library/
http://ekg.academy/learn-ekg.aspx?seq=11&courseid=315
http://my.clevelandclinic.org/services/heart/patient-education
Questions???Please email me at [email protected]
with any questions
For a copy of the materials used in this presentation please visit
http://kellymarchant.weebly.com