Basic EKG Interpretation Nirja Parikh, PT, DPT
Electrocardiogram (EKG) Using surface electrodes record the electrical activity of the heart electrical activity (usually) correlates to mechanical function Information from EKG Heart Rate Heart Rhythm Heart Size Ischemia/Infarction Drug and electrolyte abnormalities
Bachman s Bundle SA Node Internodal Branches Atrial Muscle AV Node Bundle of His R & L Bundle Branches Purkinje Fibers Ventricular Muscle Fibers
Sequence of Electrical and Mechanical Alterations
R Normal EKG T P U Q S P wave = atrial depolarization QRS = ventricular depolarization T wave = ventricular repolarization
EKG Rhythm Strips Normal & Dysrhythmias
Simple Rules of Reading EKG s Pattern Recognition Check R wave - size, shape, distance Check QRS complex (ventric depolariz=should be nice and skinny) Check P wave size, shape, distance Check PR interval Check T wave - size/shape Check ST segment Notify medical personnel when changed from normal or life threatening
Normal Sinus Rhythm (NSR) Rate between 60 and 100 beats per minute (bpm) SA Node in control Rhythm is regular (on EKG look for R wave distance to be the same)
Rate of 300: Rule of 300- Divide 300 by the number of boxes between each QRS = rate
Rate Abnormalities Normal Sinus Rhythm NSR - 60-100 bpm Bradycardia < 60 bpm This is normal in? Tachycardia > 100 bpm This is normal in?
What is the heart rate? 75 bpm
Inherent Rates SA Node = 100 bpm Atria = 75 bpm AV Node = 60 bpm Ventricles = 30-40 bpm (effect CO) Emergency rates - 150-250 bpm
Rhythms Regularly regular (NSR): normal Irregularly irregular: no pattern Regularly irregular: pattern will be there http://www.skillstat.com/learn.htm
Dysrhythmia's Alteration in: Rate Rhythm Ectopic Focus/Foci irritable cell (one bad apple) consequence gap junction
NSR Irregular R waves
Causes of Ectopic Foci (Irritable Cells) Ischemia/Hypoxia of the myocardium Sympathetic Discharge - anxiety, exercise Acidosis Alterations in electrolytes (primarily K+) Excessive stretch of the myocardium (heart failure) Pharmacological Agents SNS mimetics - caffeine Anti-arrhythmic drugs
Simple Rules of Reading EKG s Check QRS wave: Size( should not be wider then 3 small blocks) shape distance between R waves
QRS
Simple Rules of Reading EKG s Check P wave: size/shape distance from Q wave
Simple Rules of Reading EKG s Check PR interval - should be <.2 seconds or 1 large box PR interval PR interval
Simple Rules of Reading EKG s Check T wave: size/shape
Simple Rules of Reading EKG s ST segment depression measured in mm - each small box is 1 mm. myocardial ischemia ST segment
ST-Segment - Measured in mm What s this? 2 mm ST - Depression
ST Elevation Acute myocardial infarction
Premature Beats Premature atrial contractions PAC Ectopic foci from atria Premature ventricular contraction PVC Ectopic foci from ventricles
Premature Atrial Contraction (PAC) http://www.youtube.com/watch?v= I1lyBZR82dQ
Premature Ventricular Contraction (PVC)
Unifocal PVC s
Unifocal PVC
Multiifocal PVC s http://www.skillstat.com/learn.htm
Multifocal PVCs
Bigeminy - 1 Normal: 1Abnormal
Trigeminy - 2 Normal:1 Abnormal What would the pulse feel like? Regular, Regularly-Irregular, Irregularly-Irregular
Quadrigeminy - 3 Normal:1 Abnormal
More Names for PVC s Couplet
Couplet
More Names for PVC s > 3 PVC s in a row is Ventricular (V) Tach As the PT working with this patient, what would you do?
Ventricular Tachycardia - Rate of 100-200 bpm Rate? Rhythm?
Ventricular Tachycardia Non sustained VT (6 beat run of VT) Sustained VT http://www.skillstat.com/learn.htm
Consequence of V-tach
Ventricular Fibrillation What do you need to do?
More Rhythms Arial Flutter: one ecetopic Atrial Fibrillation: multiple ecetopic
Arial Flutter Can be described by: Saw tooth pattern One cell is irritated and beating fast >bpm Multiple P waves
Atrial Flutter
Atrial Fibrillation Multiple Cells http://www.skillstat.com/learn.htm
Irregularly, Irregular http://www.youtube.com/watch?v= fixspydexgm
What the Hey is Going On???? Heart rate? Atrial rate? Ectopic sites location? Will you exercise this patient if prior rhythm was NSR? Why or why not?
What is This Heart rate? Rhythm? What would you do?
Would you walk this person? Heart rate? What would you do?
AV-Node Blocks Damage or fibrotic change to the AV Node leads to varying degrees of AV Node Block 1st degree - mild 2nd degree 3rd degree complete block
1st Degree AV-Block Check PR interval - will be >.2 seconds or 1 large box PR interval Normal PR interval 1st Degree AV-Block
2nd Degree AV-Block 2-3 P Waves/QRS P P QRS P P QRS P P QRS P P QRS AV node is holding on to the signal and does not get to the ventricles SA node is still firing away 2 P waves to every QRS complex
nd Types of 2 Degree AV Block Wenckebach Every successive PR interval is longer until a QRS complex is dropped Starts all over again PR Interval PR Interval PR Interval PR Interval
Second Degree AV Block Mobitz I (Wenckebach) http://www.skillstat.com/learn.htm
nd Other Types of 2 Degree AV Block Mobitz II PR interval stay the same but a QRS complex is dropped Starts all over again PR Interval PR Interval PR Interval PR Interval
3rd Degree AV-Block Complete Block http://www.skillstat.com/learn.htm
3rd Degree AV-Block P QRS P P QRS P P QRS P
3rd Degree HB Complete HB or AV Block
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