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 Lead 2 Lead 3 From Right arm to Left arm From Right arm to Left leg Lead 3 From Left arm to Left leg *Lead 2 is the typical monitoring lead

ECG Rules 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? QRS? Wide >.12 sec Same shape

Ventricular Tachycardia

Torsades de Pointes Rate? >100/min Rhythm? No P waves? None PR Interval? 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? QRS width? Wide >.12 sec

Ventricular Fibrillation Coarse Fib Fine Fib

Idioventricular Rate? < 40/min Regular? Yes P waves? None PR Interval? QRS width? Wide > .12 sec

Idioventricular

Accelerated Idioventricular 40 – 100/min Regular? Yes P waves? None PR Interval? 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? 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? 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 Gator959@gmail.com

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…. Gator959@gmail.com