The ABCs of EKGs/ECGs for The ABCs of EKGs/ECGs for HCPsHCPs

Al Heuer, PhD, MBA, RRT, RPFTAl Heuer, PhD, MBA, RRT, RPFTProfessor, Rutgers School of Health Professor, Rutgers School of Health

Related ProfessionsRelated Professions

Learning ObjectivesLearning Objectives

Review the basic anatomy of the heartReview the basic anatomy of the heart Describe the cardiac conducting systemDescribe the cardiac conducting system Discuss the indications for EKGsDiscuss the indications for EKGs Summarize the basics of how to analyze an Summarize the basics of how to analyze an

EKG rhythmEKG rhythm Review common rhythms, causes and Review common rhythms, causes and

treatmenttreatment Furnish additional resourcesFurnish additional resources

Conducting Pathway of the Conducting Pathway of the HeartHeart

Conduction (Cont.)Conduction (Cont.)

EKG = Graphical Depiction of Cardiac EKG = Graphical Depiction of Cardiac CycleCycle

AtrialDepolarization

↓

Ventricular Depolarization

↓Ventricular

Repolarization

↓ “after potential”

↓

Indications for EKGsIndications for EKGs

Chief complains:Chief complains: Chest painChest pain Dyspnea on exertionDyspnea on exertion OrthopneaOrthopnea Pedal edemaPedal edema Fainting spellsFainting spells PalpitationsPalpitations

Past medical hx:Past medical hx: Hx of heart diseaseHx of heart disease Hx of cardiac surgeryHx of cardiac surgery

Physical examinationPhysical examination Unexplained Unexplained

tachycardia at resttachycardia at rest HypotensionHypotension Decreased capillary Decreased capillary

refillrefill Abnormal heart sounds Abnormal heart sounds

and murmursand murmurs Cool, edematous, Cool, edematous,

cyanotic extremitiescyanotic extremities DiaphoresisDiaphoresis (+) JVD(+) JVD

Limitations of EKGsLimitations of EKGs

Does Does notnot measure the pumping ability of measure the pumping ability of the heartthe heart

Does Does notnot show abnormalities on cardiac show abnormalities on cardiac structurestructure

Does Does notnot have predictive value have predictive value ArtifactArtifact Operator techniqueOperator technique Lead placement limitationsLead placement limitations Technical issuesTechnical issues

EKG AnalysisEKG Analysis

Lethal rhythm requiring immediate attention?Lethal rhythm requiring immediate attention? Is the rate normal, slow or fast?Is the rate normal, slow or fast? Is the rhythm regular?Is the rhythm regular? Is there a “P” Wave?Is there a “P” Wave? What is the PR Interval?What is the PR Interval? What is the QRS configuration?What is the QRS configuration? Are there other characteristics?Are there other characteristics?

ST depressionST depression Axis deviationAxis deviation

What is the final interpretation?What is the final interpretation? What is the recommended action/treatmentWhat is the recommended action/treatment

Gridlines = Time IntervalGridlines = Time Interval

Estimating Rate - If IrregularEstimating Rate - If Irregular

6-second technique (irregular rhythms)6-second technique (irregular rhythms) Select a 6 sec interval strip (30 large boxes)Select a 6 sec interval strip (30 large boxes) Count the # of QRS complexesCount the # of QRS complexes Multiply by 10Multiply by 10

e.g. 7 ‘QRSs’ x 10 = ~70 beats/mine.g. 7 ‘QRSs’ x 10 = ~70 beats/min

Estimating Rate - If RegularEstimating Rate - If Regular

Calculating HRCalculating HR Count the number of large boxes Count the number of large boxes

between two beats.between two beats. Divide this number into 300.Divide this number into 300. Examples:Examples:

2 large boxes: 300/2 = 1502 large boxes: 300/2 = 150 4 large boxes : 300/4 = 754 large boxes : 300/4 = 75 6 large boxes : 300/6 = 506 large boxes : 300/6 = 50

Normal EKG Rhythm & ValuesNormal EKG Rhythm & Values

Normal Values (Adult)Normal Values (Adult) Rate = 60-100Rate = 60-100 P-R Interval = 0.12- 0.20 sec.P-R Interval = 0.12- 0.20 sec. QRS QRS << 0.12 sec. 0.12 sec.

Arrhythmia EtiologyArrhythmia Etiology

Disturbance in Disturbance in automaticityautomaticity Pacemaker speeds upPacemaker speeds up New pacemaker takes overNew pacemaker takes over

Conduction problem: Conduction problem: Slowing or Slowing or blockage of conduction or electrical pulseblockage of conduction or electrical pulse

Combination of these twoCombination of these two

Sinus BradycardiaSinus Bradycardia

Why Sinus Bradycardia?Why Sinus Bradycardia? RegularRegular Rate < 60Rate < 60 1 P for every QRS1 P for every QRS PRI between .12 & .20 secondsPRI between .12 & .20 seconds QRS width = 0.12 secondsQRS width = 0.12 seconds

Common Causes?Common Causes? MIMI Vagal stimulationVagal stimulation Increased ICPIncreased ICP Normal athletic heart???Normal athletic heart???

Treatment?Treatment? Nothing, if patient asymptomaticNothing, if patient asymptomatic AtropineAtropine Pacing Pacing

Sinus TachycardiaSinus Tachycardia

Why?Why? HR between 100 & 150HR between 100 & 150 Rhythm and intervals OKRhythm and intervals OK

Common Causes?Common Causes? HypovolemiaHypovolemia FeverFever PainPain AnxietyAnxiety ActivityActivity CatacholaminesCatacholamines

Treatment?Treatment? Treat underlying causeTreat underlying cause

Supraventricular Tachycardia (SVT)Supraventricular Tachycardia (SVT)

Why?Why? Very Rapid Rate (150-250)Very Rapid Rate (150-250) P wave may be buried in preceding T waveP wave may be buried in preceding T wave PRI difficult to measure but may be between 0.12 and 0.20 PRI difficult to measure but may be between 0.12 and 0.20

secs.secs. Common Causes?Common Causes?

Ischemic heart diseaseIschemic heart disease Excessive catacholamines (e.g., epinephrine)Excessive catacholamines (e.g., epinephrine)

Treatment?Treatment? Beta BlockersBeta Blockers Calcium Channel BlockersCalcium Channel Blockers Adenosine (AV blockade)Adenosine (AV blockade)

Atrial FibrillationAtrial Fibrillation

Why?Why? No identifiable p-wavesNo identifiable p-waves Chaotic irregular baselineChaotic irregular baseline QRS distinguishable but irregular & < .12 secsQRS distinguishable but irregular & < .12 secs

Common CauseCommon Cause Enlarged atrium (due to CHF or mitral stenosis)Enlarged atrium (due to CHF or mitral stenosis)

Clinical significance:Clinical significance: Threat of emboliThreat of emboli Decreased cardiac outputDecreased cardiac output

If rapid rate = less ventricular fillingIf rapid rate = less ventricular filling Loss of “Atrial kick” Loss of “Atrial kick”

Treatment?Treatment? Beta Blockers (Lopressor)Beta Blockers (Lopressor) Calcium Channel Blockers (Cardizem)Calcium Channel Blockers (Cardizem) DigoxinDigoxin CardioversionCardioversion

Atrial FlutterAtrial Flutter

Why?Why? P waves not present with “P waves not present with “Sawtooth”Sawtooth” baseline baseline PRI not measurablePRI not measurable QRS less than 0.12 secondsQRS less than 0.12 seconds

Common causes?Common causes? Ischemic heart diseaseIschemic heart disease Rheumatic heart diseaseRheumatic heart disease

Treatment?Treatment? Beta Blockers (Lopressor)Beta Blockers (Lopressor) Calcium Channel Blockers (Cardizem)Calcium Channel Blockers (Cardizem) DigoxinDigoxin CardioversionCardioversion

Premature Ventricular Contraction Premature Ventricular Contraction (PVC)(PVC)

Why?Why? Premature beat makes rhythm appear irregularPremature beat makes rhythm appear irregular PVC is not preceded by a P-wavePVC is not preceded by a P-wave PRI is not measurablePRI is not measurable

Common Causes?Common Causes? HypokalemiaHypokalemia MI or ischemiaMI or ischemia HypoxemiaHypoxemia HypovolemiaHypovolemia

Treatment?Treatment? Treat underlying causeTreat underlying cause Beta blockersBeta blockers Antiarrhythmic drugs (Amiodarone or Lidocaine)Antiarrhythmic drugs (Amiodarone or Lidocaine)

Ventricular TachycardiaVentricular Tachycardia

Why?Why? Rate generally between 100 & 200Rate generally between 100 & 200 P-waves not presentP-waves not present PRI not measurablePRI not measurable QRS wide and bizarre, width > 0.12 secondsQRS wide and bizarre, width > 0.12 seconds

Common Causes?Common Causes? Similar to PVCsSimilar to PVCs

Treatment?Treatment? If pulse & stable: Similar antiarrhythmic drugs as PVCsIf pulse & stable: Similar antiarrhythmic drugs as PVCs If pulseless, then immediately begin CPR and rapid defibrillationIf pulseless, then immediately begin CPR and rapid defibrillation

Ventricular FibrillationVentricular Fibrillation

Why?Why? Chaotic rhythmChaotic rhythm HR can not be determinedHR can not be determined P-waves, PRI and QRS not discernableP-waves, PRI and QRS not discernable

Causes?Causes? MI or ischemiaMI or ischemia AcidosisAcidosis HypothermiaHypothermia HypoxemiaHypoxemia

Treatment = ABCDs of ACLS, including immediate defibrillationTreatment = ABCDs of ACLS, including immediate defibrillation

AsystoleAsystole

Causes:Causes: Electrolyte disturbancesElectrolyte disturbances PneumothoraxPneumothorax Drug overdoseDrug overdose HypoxemiaHypoxemia Post MIPost MI

Treatment = Treatment = Not shockableNot shockable Immediate CPR, unless a valid DNR Immediate CPR, unless a valid DNR Identify and treat underlying causeIdentify and treat underlying cause PacingPacing Basic troubleshooting.Basic troubleshooting.

Pulseless Electrical Activity Pulseless Electrical Activity (PEA): (PEA): Electrical Conduction without Mechanical Electrical Conduction without Mechanical

Activity of the Heart.Activity of the Heart. Most common causes are as Most common causes are as follows:follows: 5 H’s: 5 H’s:

Hypovolemia, Hypovolemia, Hypoxia, Hypoxia, H+(acidosis), H+(acidosis), Hyper/hypokalemiaHyper/hypokalemia HypothermiaHypothermia

5 T’s: 5 T’s: Tamponade Tamponade

(cardiac), (cardiac), Tension pneumo, Tension pneumo, Thrombosis Thrombosis

(coronary), (coronary), Thrombosis Thrombosis

(pulmonary) (pulmonary) Tablets (OD)Tablets (OD)

First Degree Heart BlockFirst Degree Heart Block

Why? Why? Regular rhythmRegular rhythm Rate 60-100Rate 60-100 QRS < 0.12 secsQRS < 0.12 secs PRI Interval > 0.20 secsPRI Interval > 0.20 secs

Causes?Causes? Physiologic interference with conduction pathwayPhysiologic interference with conduction pathway Digoxin toxicityDigoxin toxicity

Treatment?Treatment? May be benignMay be benign Treat underlying causeTreat underlying cause Stop digoxin, if levels are highStop digoxin, if levels are high

22ndnd Degree Heart Block-Type I Degree Heart Block-Type I (Wenckebach)(Wenckebach)

Why?Why? Irregular rhythmIrregular rhythm Ventricular rate < atrial rateVentricular rate < atrial rate Progressive prolongation of PRI interval until a QRS is Progressive prolongation of PRI interval until a QRS is

droppeddropped Causes?Causes?

Mi or ischemiaMi or ischemia Excessive beta blockersExcessive beta blockers Digoxin toxicityDigoxin toxicity

Treatment?Treatment? Atropine if symptomatic heart rate < 60Atropine if symptomatic heart rate < 60 MonitorMonitor

Second Degree Heart Block-Second Degree Heart Block-Type IIType II

Why?Why? Regular rhythm Regular rhythm Ventricular rate < atrial rateVentricular rate < atrial rate QRS does not occur with every p-wave (some QRS’s are dropped)QRS does not occur with every p-wave (some QRS’s are dropped) More p- waves than QRSMore p- waves than QRS

Causes?Causes? MI or ischemiaMI or ischemia Excessive beta blockersExcessive beta blockers Digoxin toxicityDigoxin toxicity

Treatment?Treatment? Atropine if symptomatic heart rate < 60Atropine if symptomatic heart rate < 60 Pacemaker Pacemaker

Third Degree Heart BlockThird Degree Heart Block

Why? Why? Independent atrial (P wave) and ventricular activity. Independent atrial (P wave) and ventricular activity. The atrial rate is always faster than the ventricular rate. The atrial rate is always faster than the ventricular rate. HR often < 40HR often < 40 PRI not measurablePRI not measurable QRS may be > 0.12 seconds QRS may be > 0.12 seconds

Causes?Causes? MI or ischemiaMI or ischemia Digoxin toxicityDigoxin toxicity

Treatment?Treatment? AtropineAtropine PacemakerPacemaker

Idioventricular RhythmIdioventricular Rhythm

Why? Why? Ectopic foci takes over as pace maker for ventriclesEctopic foci takes over as pace maker for ventricles No “P” waves No “P” waves Wide QRS (> 0.12 secs)Wide QRS (> 0.12 secs) Rate 30-40, unless acceleratedRate 30-40, unless accelerated

Common causes?Common causes? MIMI

Treatment?Treatment? PacingPacing AtropineAtropine

A B

C

Myocardial Infarction

Myocardial Ischemia

Normal S-T Segment

Other EKG Abnormalities:Other EKG Abnormalities:ST Segment Elevation & Depression ST Segment Elevation & Depression

ST Elevation with a PVCST Elevation with a PVC

Cause: Acute MICause: Acute MI Treatment: Treatment:

TPA (“clot busters”)TPA (“clot busters”) Vasodilators Vasodilators RevascularizationRevascularization

S-T Segment DepressionS-T Segment Depression

Cause: Myocardial IschemiaCause: Myocardial Ischemia Treatment: Treatment:

VasodilatorsVasodilators OxygenOxygen RevascularizationRevascularization

Right Axis DeviationRight Axis Deviation

Quick Axis DeterminationQuick Axis DeterminationLeadLead Axis InterpretationAxis Interpretation

I is PositiveI is PositiveII is PositiveII is Positive

NormalNormal

I is PositiveI is PositiveII is II is Negative Negative

Left Axis deviationLeft Axis deviation

I is NegativeI is NegativeII is PositiveII is Positive

Right Axis DeviationRight Axis Deviation

I is NegativeI is NegativeII is II is NegativeNegative

Extreme Right axis Extreme Right axis DeviationDeviation

Identifying Axis DeviationIdentifying Axis Deviation

Also: With Right Axis Deviation, Also: With Right Axis Deviation, lead 3 will positive, but taller lead 3 will positive, but taller than lead II. than lead II.

Causes of Axis Deviation:Causes of Axis Deviation:

Right Axis DeviationRight Axis Deviation Right ventricular Right ventricular

hypertrophyhypertrophy COPDCOPD Acute PEAcute PE Infants (normal)Infants (normal) Bi-ventricular Bi-ventricular

hypertrophyhypertrophy

Left Axis DeviationLeft Axis Deviation Left ventricular Left ventricular

hypertrophyhypertrophy Abdominal obesityAbdominal obesity Ascites or large Ascites or large

abdominal tumorsabdominal tumors Third trimester Third trimester

pregnancypregnancy

Take Home MessagesTake Home Messages Decide What it is you Decide What it is you Need/WantNeed/Want to to

know about EKGs/ECGsknow about EKGs/ECGs Identify resourcesIdentify resources

TextsTexts ManualsManuals Actual EKG stripsActual EKG strips

Review and reinforceReview and reinforce Obtain and maintain ACLSObtain and maintain ACLS Know thy limitations Know thy limitations

Additional ResourcesAdditional Resources

Aehlert B: Aehlert B: ECGs made easyECGs made easy, ed. 3, Mosby 2005., ed. 3, Mosby 2005. American Heart Association: American Heart Association: Advanced Advanced

cardiovascular life supportcardiovascular life support, AHA, 2008., AHA, 2008. Goldberger AL: Goldberger AL: Clinical electrocardiography: a Clinical electrocardiography: a

simplified approachsimplified approach, ed. 7, Mosby 2006. , ed. 7, Mosby 2006. Heuer A & Scanlan C: Clinical Assessment in Heuer A & Scanlan C: Clinical Assessment in

Respiratory Care, ed 7, Elsevier, 2013Respiratory Care, ed 7, Elsevier, 2013 Thaler MS: Thaler MS: The only ECG book that you’ll ever The only ECG book that you’ll ever

needneed, ed. 5, Lippincott-Raven, 2006., ed. 5, Lippincott-Raven, 2006. www.ecglibrary.comwww.ecglibrary.com