EKG Crash Course

The QRS Interval

ECG Graph Paper Horizontal= timeVertical= voltage

Each tiny box is equal to 0.04 seconds, therefore every large box is equal to 5 times that- 0.20 seconds.

Another view

WaveformsP waveP-R intervalQRS complexST segmentT waveQT intervalU Wave

Steps to Analyzing Rhythms1- Determine regularity2- Calculate rate3- Identify P waves4- Measure PR interval5- Identify P:QRS ratio6- Measure QRS duration7- Measure the QT interval

Step 1: Determine Regularity

Step 2: Calculate Heart Rate Count the number of QRS complexes in a 6 second strip

6 QRS complexes x 10 = 60 beats per minute

Step 3: Identify P Wave Find the P wave that precedes the QRSLook at several of the P waves

The P waves should be identical in shape, size and position

Step 4: Measure the PR interval Beginning of P to the beginning of the QRS

Count the number of small boxes x 0.04 seconds

Normal PR interval is 0.12 - 0.2

Step 5: Identify P:QRS RatioDetermine how many P waves precede each QRSNormal is 1:1there should be a P for every QRS, or else rhythm is irregular

Step 6: Measure the QRS Duration Beginning of the QRS to the end of QRS (when ST begins)Normal < 0.12 seconds

Step 7: Measure the QT Interval Measure from start of the QRS to the end of the T waveCount boxes and multiply by 0.04 secondsNormal QT Interval is 0.32 to 0.44 (dependent on HR)

Lead Choicedetermines direction of deflections

Normal Sinus RhythmRhythm: RegularRate: 60-100P waves: Normal, each P wave precedes each QRSPR interval: 0.12-0.2 sec QRS ratio: 1:1QRS duration: 0.04-0.1(0.12) secQT interval: 0.32 to 0.44 sec

Sinus BradycardiaRhythm: RegularRate: < 60P waves: Normal, each P wave precedes each QRSPR interval: 0.12-0.2 sec QRS ratio: 1:1QRS duration: 0.04-.1(0.12) secQT interval: 0.32 to 0.44 sec

Sinus TachycardiaRhythm: RegularRate: > 100P waves: Normal, each P wave precedes each QRSPR interval: 0.12-0.20 sec QRS ratio: 1:1QRS duration: 0.04-.10 secQT interval: 0.32 to 0.44 sec

Sinus DysrhythmiaRhythm: IrregularRate: 60-100P waves: Normal, each P wave precedes each QRSPR interval: 0.12-0.2 sec QRS ratio: 1:1QRS duration: 0.04-.1 sec

You will see strips that are not this obvious; this is why you must measure the R to R interval each time!

Sinus Arrest Rhythm: IrregularRate: 60-100. Often less than 60 bpmP waves: Normal but absent during pausePR interval: 0.12-0.20 sec

Wandering Atrial PacemakerRhythm: Regular or irregularRate: 60-100P waves: Vary in size and shape. This is a distinct characteristic.PR interval: May vary QRS duration: 0.04-.10 sec

Atrial Fibrillation Rhythm: IrregularRate: Ventricular rate varies but atrial rate is > 400 (atrial rate is calculated by counting the number of bumps you see between the QRS complexes).P waves: AbsentPR interval: Not measurableQRS duration: 0.4-.10 sec

Atria FibrillationMay convert without treatment May receive:AnticoagulationMedications to reduce Ventricular response: Beta Blockers Nondihydropyridine CCB digitalis

Atrial FlutterRhythm: Regular or irregularRate: Atrial rate which are the bumps between the R wave is between 250-400P waves: Flutter waves saw tooth patternPR interval: Not measured QRS duration: 0.4-.10 sec

FlutterChest pain, SOB low BPElectrical cardioversionAnticoagulationMedications to reduce Ventricular response: Beta Blockers Nondihydropyridine CCB(diltiazem & verapamil) Digitalis

Cardio VersionDefibrillator in synchronized modeCardiac monitor AnticoagulatedNPOSedationGel pads/paddles Anterior and PosteriorAmbuBagVolatge measured in Joules 50 - 360

Cardio Version

Electrical Cardioversion

NO Beta-Blocker for Asthmatics NO verapamil (CCB) for impaired Ventricles NEITHER with AV BLOCK

???Is this regular or irregular?

Premature Ventricular Contraction (PVC)Rhythm: Regular except for the PVCP waves: Normal with basic rhythmPR interval: 0.12-0.20 sec QRS duration: 0.04-.10 sec

Ventricular TachycardiaRhythm: regularRate: >100P waves: NonePR interval: NoneQRS duration: > 0.10 sec

Supraventricular Tachycardia (SVT)Rhythm: RegularRate: >160P waves: May be hidden or present

Some causes of SVT are various medication medications (broncodialators) and caffeinePatient might have chest pain, feel palpitations and feel numbness in various body parts.

Torsades de pointes Means twisting of the points in FrenchRhythm: IrregularRate: >100P waves: NonePR interval: NoneQRS duration: > 0.10 sec

Ventricular FibrillationRhythm: ChaoticRate: 0P waves: NonePR interval: NoneQRS duration: None

coarsefine

Defibrillation Txt of Choice for V fibrillationPulseless VT NOT for those who have LOC or Pulse!!!!

Defibrillation Mono phasic & Biphasic

Cardio Version

Defibrillation

Good contact c conductive gelNO one in contact with patient or bedCLEAR x 3

Bundle Branch BlockEasy to recognize Notched QRSQRS duration is > 0.12 seconds

First Degree Heart BlockRhythm: RegularP waves: NormalPR interval: > 0.20 sec ELONGATEDQRS duration: 0.04-.10 sec

Second Degree Heart Block Type 1 (Mobitz 1 or Wenckebach) 1. PR progressively lengthens until beat is dropped.2. Regular atrial rhythm, irregular ventricular rhythm.

Second Degree Heart Block Type 2 (Mobitz 2) PR constantQRS wide block involves both branchesP:QRS ratio 2:1 3:1 4:1Regular atrial rhythm, Irregular ventricular rhythm

Third Degree Heart Block Type 3 PR variesP waves have no constant relationship to QRSRegular atrial rhythmregular ventricular rhythm

Pulseless Electrical Activity(PEA)

Nursing Assessment is critical..Why?

Asystole Nursing Action ??

What do you see?

12 Lead EKG

Cardiac Leads - Einthovan's Triangle

Lead IILead III

The View from 12 leads

Pacemakers.. An introduction

Atrial PacingPacing spike Response ??

V pacingPacing spike with generated beat P

Patient generated beat C

************Depending on what lead the rhythm is being read off of, a normal rhythm could look irregular to a beginner The bottom rhythm is actually to same at the top but is inverted

******************Atrial rate usually 60-100 faster than ventricularVentric Rhythm irregORS usually wideCardiac output is compromised and can lead complete av blockCommon with MI

**A rhythm will appear on a telemetry monitor and EKG but patient will be pulseless.This is why in a code it is important to assess a patients pulse before assuming they are back to a normal rhythmPEA strips can look like numerous rhythms

***A pacemaker is an electrical device that is implanted near the heart. It can be permanent or temporary and causes the heart to beat when it does not automatically. The wires can be either to pace the ventricle or the atrium. Hence the name A pacing or V pacing.

*Atrial pacing but no response rom the Ventrical THEN ventricular pacing **