12 Lead EKG Interpretation

transcript

Unraveling the Mysteries of the

12 Lead EKG

Developed by the

Objectives

• Identify the correct lead placement for performing a 12 lead EKG

• Identify and interpret heart rhythm and differing blocks

• Identify extreme axis deviations

• Identify and interpret bundle branch blocks

• Interpret MI location based on ST elevation

ECG Pre-test

• Is this ECG normal? A. True B. False

• Is this ECG normal? A. True B. False - Wenkebach

• Would you call a STEMI alert? A. Yes B. No

• Would you call a STEMI alert? A. Yes B. No - RBBB

• Does this person need anticoagulation? A. Yes B. No

• Does this person need anticoagulation? A. Yes – Atrial fibrillation B. No

• The initial treatment of choice for this rhythm is cardioversion. A. True B. False

• The initial treatment of choice for this rhythm is cardioversion. A. True B. False – SVT (try adenosine first)

• This ECG explains the patient’s complaints of dizziness. A. True B. False

• This ECG explains the patient’s complaints of dizziness. A. True – sinus bradycardia with heart rate of 37 bpm B. False

How did you do?

OK – let’s get started!!

Monitoring vs Assessing

• Monitoring – EKG leads can be placed anywhere

– Allows for identification of VF and Asystole

• Assessing – EKG leads MUST be placed in specific locations

– Allows for interpretation of changes in the electrical conduction (depolarization and repolarization changes) i.e., ischemia.

Patient Preparation

• Provide a level of privacy

• Remove the patient’s shirt

• Shave the chest

• Prep the skin

– Remove the dead epithelials

• Electrically non-conductive

• Place the patient in a hospital gown

YES! – Women Too

• Remove the bra

• Use a sheet to drape the patient

• Diaphoresis

– Dry the chest

– Use alcohol

– Use benzene

Patient Position

• Place the patient in the correct position to acquire the EKG

– Supine Recommended

– Sitting up is fine

• Ask the patient to hold still

• Keep their hands down by their side

– May need to hold the patient’s hands

Lead Placement

• 12 Lead ECG’s use 10 Electrodes

– one electrode on each limb

– 6 electrodes on the left chest

Lead Placement

• Limb Lead go on the LIMBS!

– LA Left ARM

– RA Right ARM

– LL Left LEG

– RL Right LEG

Left Chest Lead Placement

• Precordial Leads (V leads or MCL leads)

– V1 4th intercostal space, right of sternum

– V2 4th intercostal space, left of the sternum

– V3 between V4 and V2

– V4 5th intercostal space, left of sternum

Left Chest EKG

The Normal Conduction System

Normal ECG

Limb Lead Reversal

Waveforms

QRS Labeling

Q Waves

First negative deflection after the

P waves in any lead

Q wave

QRS Labeling

R Waves

First positive deflection after the

P waves in any lead

QRS Labeling

S Wave

Negative deflection below the

baseline after an "R" or "Q" wave

QRS Labeling

The "J" Point

Also called the" juncture" point.Where the qrs complex endsand the ST segment begins

QRS Labeling

QRS MorphologiesCan you label these complexes?

Now YOU Do It!

• Video of proper ECG lead placement

Interpretation

• Develop a systematic approach to reading EKGs and use it every time

• The system recommended is: – Rate

– Rhythm (including intervals and blocks)

– Axis

– Ischemia

• Rule of 300- Divide 300 by the number of boxes between each QRS = rate

Number of big boxes

Estimate of Heart Rate

What is the heart rate?

(300 / 6) = 50 bpm

www.uptodate.com

• HR of 60-100 per minute is normal

• HR > 100 = tachycardia

• HR < 60 = bradycardia

Differential Diagnosis of Tachycardia

Tachycardia Narrow Complex Wide Complex

Regular ST

Atrial flutter

ST w/ BBB

SVT w/ BBB

Irregular A-fib

A-flutter w/ variable conduction

A-fib w/ BBB

A-fib w/ WPW

Rhythm

• Sinus

– Originating from SA node

– P wave before every QRS

– P wave in same direction as QRS

What is this rhythm?

Normal Intervals

• PR – 0.20 sec (less than one

large box)

• QRS – 0.08 – 0.10 sec (1-2 small

boxes)

• QT – 450 ms in men, 460 ms in

– Based on sex / heart rate

– Half the R-R interval with normal HR

Causes of Prolonged QT

• Causes – Drugs

– Hypocalcemia, hypomagnesemia, hypokalemia

– Hypothermia

– AMI

– Congenital

– Increased ICP

Consequences of Prolonged QT

Blocks

• AV blocks – First degree block

• PR interval fixed and > 0.2 sec

– Second degree block, Mobitz type 1 • PR gradually lengthened, then drop QRS

– Second degree block, Mobitz type 2 • PR fixed, but drop QRS randomly

– Type 3 block • PR and QRS dissociated

First degree AV block

PR is fixed and longer than 0.2 sec

Type 1 second degree block (Wenckebach)

3rd degree heart block (complete)

Section Two

• Axis: predominant flow of electricity through the heart

• We look at the QRS complexes for ventricular axis

III II

NORMAL AXIS

Hexaxial Reference System

• Divided into 6 part grid – Based on the leads

• I • II • III • aVR • aVF • aVL

• Degrees of electrical flow – 0 to +180 – 0 to -180

ECG with Normal Axis

Extreme Right Axis

-90 to -180 degrees

ECG with Extreme Right Axis

Differential Diagnosis of Extreme Right Axis

• Ventricular tachycardia

• Hyperkalemia (acute renal failure)

• Apical MI

• Right Ventricular Hypertrophy

Limb Lead Reversal

Hemiblocks

• A hemiblock is a block of one of the fascicles of the left bundle branch.

• Hemiblock is an ECG diagnosis

Left Bundle Branch

Posterior Hemifascicle

Anterior Hemifascicle

Hemiblocks

• Anterior Hemiblock

– pathological left axis

– negative deflection in leads II and III

– small q in lead I, small r in lead III

– common block

– 4x higher mortality rate in AMI

Left Bundle Branch

Anterior Hemiblock

Hemiblocks

• Posterior Hemiblock

– right axis deviation

– small r in lead I, small q in lead III

– high mortality rate when with an AMI

– two coronary arteries involved

Left Bundle Branch

Posterior Hemifascicle

Posterior Hemiblock

• Very rare and much more dangerous.

• Posterior hemifascicle has redundant blood supply from two separate coronary arteries.

• In setting of an acute MI, two coronary arteries would have to be occluded proximally in order to create this condition.

Posterior Hemiblock

Rapid Axis

• Rapid Axis and Hemiblock Chart

Lead I Lead II Lead IIIAxis

Normal Axis

0 - 90

PhysiologicLeft Axis0 to -40

Pathological Left Axis

-40 to -90

Right Axis

90 - 180

Extreme RightAxis

Posterior

no man's land

Ventricular in

origin

Comments

Test Your Knowledge!

Normal Axis

Leftward Axis (normal)

Left Anterior Hemiblock

Left Posterior Hemiblock

Extreme Right Axis

Ventricular Tachycardia

• 12 Lead ECG and VT:

• You may be the only one to see the rhythm

• A 12 lead ECG of VT is very helpful to the cardiologist looking for the cause

• More benefit and less risk in knowing for sure

Ventricular Tachycardia

• Rate 110 -250 bpm

• Wide complex (>0.12 – 3 small blocks)

• Regular

• AV dissociation

• Extreme Right Axis Deviation + Upright MCL-1

I III II III

II III

EXTREME RIGHT AXIS ERAD

Bundle Branch Blocks

• A Bundle Branch Block is a block of one of the two bundle branches, left or right

• A Bundle Branch is a fascicle of electrical conduction system cells designed to carry impulses to the ventricles

• Bundle Branches facilitate “syncytium” or both ventricles contracting in sync.

• Turn Signal Theory

– easy way to determine left or right BBB

– use lead V1

– QRS complex must be at least .12sec (120 ms) or wider (or 3 little squares)

– Use lead V1 or MCL-1 IF QRS > 120 ms (.12 sec)

– Circle the J point

– Draw line back into the complex, then up or down with the terminal deflection

– shade in the triangle made by this line

– Arrow points up - turn signal up - Right BBB

– Arrow points down - turn signal down - Left BBB

QRS Labeling

QRS MorphologiesCan you label these complexes?

LBBB LBBB

RBBB RBBB

Can You Identify These Bundle Branch Blocks?

Right Bundle Branch Block and Hemiblocks can occur together!

RBBB + Anterior Hemiblock (most commonly seen)

Left Bundle Branch

Right Bundle Branch

RBBB + LAHB

Section Three

Myocardial Blood Supply

AMI Myocardial Blood Supply

• Right Coronary Artery

• Inferior Wall (LV)

• Posterior Wall (LV)

• Right Ventricle

• SA and AV Node

• Posterior fascicle of LBB

• Left Anterior Descending

• Anterior Wall of LV

• Septal Wall

• Bundle of His and BB

• Circumflex

• Lateral Wall of LV

• Rarely SA and AV nodes

• Posterior Wall of LV

Clinical Manifestations of

Arterial Thrombosis

UA/NSTEMI: Partially-occlusive thrombus

(primarily platelets)

Intra-plaque

thrombus (platelet

dominated)

Plaque core

ST MI: Occlusive thrombus (platelets,

red blood cells, and fibrin)

Intra-plaque

thrombus (platelet

dominated)

Plaque core

SUDDEN DEATH

Adapted from Davies MJ. Circulation. 1990; 82 (supl II): 30-46.

ECG Signs of Ischemia

• Usually indicated by ST changes

– Elevation = Acute infarction

– Depression = Ischemia

• Can manifest as T wave changes

• Remote infarction can be shown by q waves

ECG Progression in Infarct

• ECG pattern in AMI = continuum that extends from normal to full infarct.

• First: T wave flips in early ischemia.

• Then: ST elevation either flat or tombstoning (flipped T wave may disappear).

• Finally: We see Q waves.

12 Lead ECG and AMI

• Benefits of 12 Lead ECG’s

– Highly specific (90% + confidence)

– If it shows an MI, there probably is an MI

– Rapid identification of MI in early stages

– Can commit to treat with ECG, history and physical exam

– Complications can be identified

12 Lead ECG and AMI

• Limitations

– Only 46 - 50 % sensitive (may miss 50%)

• Increase sensitivity by looking at the whole heart

– Diagnostic quality necessary

– Training needed to read the 12 leads

– ECG evidence is only one piece of the puzzle

– Some non-MI conditions look like MI’s

12 Lead ECG and AMI

A NORMAL 12 LEAD ECG DOES NOT RULE OUT A MYOCARDIAL

INFARCTION

If there is suspicion for MI, repeat the ECG

Acute Ischemia

• Area of ischemia is more negative than surrounding normal tissue • Causes ST depression; T wave is flipped • Causes repolarization to occur along abnormal pathway

Acute Injury

• Zone of injury does not repolarize completely

• Remains more positive than surrounding tissue, leading to ST elevation

• T remains flipped (abnormal repolarization paths along injured/ischemic areas of myocardium)

Cardiac Location of Event

Posterior MI Is there a lead for that?

• You only find what you’re looking for!

– Move V4, V5, V6

– 5th intercostal space

Posterior MI

• Look for anterior reciprocal changes

What about the right side? RV infacts

• Move V4 to the right side same location

– 5th intercostal space anterior axillary

Occur in conjunction with inferior MIs

Acute MI with RV involvement

Where/What is It?

Scorecard

• The guidelines call for a 90 minute medical contact to balloon time.

• Very important to perform immediate or in-field ECG to make earlier diagnosis to start the STEMI alert.

Interventional Plan for EMS

• Out of hospital 12 lead

• Early notification of hospital

• O2, NTG, pain control

• ASA, Heparin

• Thrombolytic prescreen

• Transport to PCI Center

Definitive AMI Treatment Percutaneous Coronary Intervention

When to Consider Thrombolytics

• Acute MI patients in whom first medical contact to balloon time is like to exceed 2 hours.

• Cath lab is not available.

How do thrombolytics or more appropriately fibrinolytics work?

• A naturally occurring blood protein Plasminogen activates the production of plasmin – a digestive enzyme

• Presence of a clot causes the endothelia cells to secrete tissue plasminogen activator which starts the breakdown of the clot

How do fibrinolytics work?

• Fibrinolytics

– Destroy the clot

at the level of the fibrin.

– Activate the production

of plasmin to cause the

digestion of the clot

EMS and the AMI: Making a difference

• Early recognition and treatment

• Early activation of cath lab

• Once infarction begins 500 myocardial cells die each second

• Salvage myocardium

• Decreased incidence of CHF

• Maintain active lifestyles

Infarct Caveats

• Anterior Wall MI

– most lethal (highest mortality)

– can suddenly develop, CHB, VF or VT

– if seen with hemiblocks or BBB, place quick combo pads on the patient and prepare for the worst

– can extend to septum (anteroseptal) or lateral (anterolateral)

– nitrates are great, fluids are spared

Infarct Caveats

• Inferior MI

– Most common seen. Can be fatal

– 50% have posterior and right ventricle involved

– Patients may have bradycardia and hypotension

– Could also have 1st degree or Mobitz 1 blocks

– Nausea is common, phenergan or compazine

– Use nitrates with caution, may need fluids

Infarct Imitators

• Left Bundle Branch Block

– late depolarization makes ST elevation difficult to distinguish

– LBBB considered a non-diagnostic ECG

• Left Ventricular Hypertrophy

– won’t have reciprocal changes

• Early Repolarization

(…but is it really benign?)

Benign early repolarization

Who gets it?

• 2-5% of the general population (Wellens, 2008)

• Usually the young and physically fit

• More prominent in African-Americans

• Generally disappears with advancing age

What does it look like?

Red arrows: concave up ST-segment elevation anteriorly Blue arrows: hyperdynamic, symmetrical, concordant T-waves 119

Classic findings

1. J-point “notching”

2. Concave-up ST segment (smiley face)

3. ST segment elevation from baseline in V2-V5, typically <3mm

4. Large, symmetrically concordant T-waves in leads with STE

Can we tease it out?

• The degree of ST segment elevation is thought to be indirectly proportional to the degree of sympathetic tone

• In other words, the more relaxed the patient, the more pronounced the ST segment elevation (and vice versa)

• If you truly want to test your patient, get their heart rate up and look at the ST segment

14yo M w/ palpitations HR: 64

1. Notched J-point 2. Concave down ST

elevation in precordial leads

Same patient after asking him to do 2min of jumping jacks in the room to try and get his heart rate up… HR 83 (up 20bpm from previous) 124

HR 64 HR 83

The ST segment is NOT fixed in pts w/ BER and changes from EKG to EKG and with the degree of sympathetic strain On the right, note the complete resolution of the ST elevation but maintenance of the J-point notching in V4

Early Repolarization

• Should be a diagnosis of exclusion and should ALWAYS be placed in clinical context!!!

• The above was taken in a patient with difficulty breathing and chest pain…and is an Myocardial Infarction -- NOT Early Repolarization!!! 126

Pericarditis

• Pericarditis is an inflammation of the pericardium (sac that surrounds the heart).

• This often occurs as a result of a viral infection.

• However, this can cause severe chest pain and can lead to ST elevation in all leads.

• Therefore, it is important to distinguish acute pericarditis from acute myocardial infarction.

Pericarditis

• Diffuse ST elevation

Pericarditis

• PR segment depression, usually in lead II

Pericarditis Treatment

• NSAIDs

• Colchicine

• Occasionally steroids

• Anticoagulation could cause a hemorrhagic pericardial effusion – life threatening.

Section 4

• ECG Tests are next!

ECG Quiz

EKG #1

1. What is the rhythm? a. V-Tach b. A-Fib c. A-flutter d. normal 133

EKG #2

1. What does this EKG represent? a. pericarditis b. myocarditis c. digitalis effect d. inferior wall ST-elevation MI

EKG #3

1. What is the rhythm? a. V-Tach b. A-Fib c. A-flutter d. normal 135

EKG #4

1. What does this EKG represent? a. sius bradycardia b. sinus tachycardia c. 2nd degree AV block d. complete heart block

EKG #5

1. What does this EKG represent? a. V-fib b. left bundle branch block c. right bundle branch block d. normal 137

EKG #6

1. What does this EKG represent? a. V-fib b. left bundle branch block c. right bundle branch block d. normal

EKG #7

1. What does this EKG represent? a. V-fib b. A-fib c. Supraventricular tachycardia d. normal

EKG #8

1. What does this EKG represent? a. V-fib b. A-fib c. A-flutter d. V- tach

EKG #9

1. What does this EKG represent? a. V-fib b. sinus bradycardia c. complete heart block d. sinus tachycardia 141

EKG #10

1. What does this EKG represent? a. V-fib b. left bundle branch block c. right bundle branch block d. normal

EKG #11

1. What diagnostic test would be the best to order next? a. Echo b. CTA c. Cath 143

EKG #12

1. What therapy would be the best to order next? a. Thrombolytic therapy b. Emergent cath and PCI c. Toradol IV

STEMI Alerts

Would You Activate the STEMI

Alert Team?

• This is an large anteroseptal, anterior,

and anterolateral MI

Alert Team?

• This is Pericarditis – inflammation of the

sac around the heart.

– Diffuse ST elevation

– PR segment depression

– Younger

– Recent viral syndrome

– Hurts worse with deep breaths or lying

Alert Team?

• This is new-onset Left Bundle Branch

• Also note the lateral ST elevation

Alert Team?

Previous ECG (from 2011)

• This is a chronic Left Bundle Branch

• Marker of CAD, heart valve disease, as

well as hypertension.

Alert Team?

• This is a PACED rhythm!

• No interpretation of the ECG is possible.

Alert Team?

• This is Early Repolarization.

– Early repolarization is a common ECG variant,

characterized by either terminal QRS slurring

(the transition from the QRS segment to the ST

segment) or notching (a positive deflection

inscribed on terminal QRS complex) associated

with concave upward ST-segment elevation

and prominent T waves in at least two

contiguous leads.

• This is Early Repolarization.

– This benign ECG phenomenon is noted in 1%

to 2% of the adult population and generally

occurs in the absence of myocardial disease.

– People with this mostly consist of men, young

adults, athletes, and people of African American

heritage

Alert Team?

• This is an inferior – posterior – lateral MI

Alert Team?

• This is Ventricular Tachycardia – and

likely is related to MI

Alert Team?

• This is an acute Anterior Wall MI with

Ventricular Bigeminy

Would You First Activate the

STEMI Alert Team?

• Shock that!

• While MI may be the reason for Vfib, other

reasons also need to be excluded.

• Consider Hypothermia Therapy in route

Section 5

Review of MHCA Protocols

• STEMI

• Stroke

Goals for STEMI

• First Medical Contact (FMC) to PCI < 90 minutes

• Door to ECG time < 10 minutes

• Door In / Door Out Time < 30 minutes

• FMC to Non-PCI hospital to PCI < 120 minutes

EMS specific

• Ideal for all chest pain patients to have in-field ECG

• Pre-hospital Activation of STEMI network

• Diversion to STEMI hospital 172

EMS Requirements

Equip all ambulances in state with ECG machines by 2012

Ambulance services should obtain EKG within 15 minutes for

typical chest pain in anyone > 30 years, and

atypical chest pain in all patients 50 and older

EMS should interpret and transfer ECG to affiliated ED

EMS personnel need training / certification in ECG interpretation of STEMI

ECG + Symptoms

• Chest pain,fullness, or pressure

• Radiation to jaw, teeth, shoulder, arm, or back

• Shortness of breath

• Epigastric discomfort

• Sweating

• Dizziness

• Cognitive impairment

EMS Requirements

+ EKG patients directly to PCI hospital if 90 minutes window obtainable from first med contact to PCI AND patient is hemodynamically stable

+ EKG patients directly to PCI hospital if 90 minutes window obtainable from first med contact to PCI BUT patient is hemodynamically UNSTABLE

Go to nearest ED

Activate Air Transport immediately for transfer to PCI center

EMS Requirements

If no pre-hospital ECG available for a chest pain patient who arrives at a non-PCI hospital

Keep the patient on the EMS stretcher until ECG performed

If EKG results + transfer to PCI hospital with SAME ambulance if patient hemodynamically stable

STEMI Network (24/7) PCI Centers

Jackson

St. Dominic

Hattiesburg

Forrest General Hospital

Wesley

Meridian

Jeff Anderson Hospital

Rush Hospital

Tupelo

North Mississippi Medical Center

Oxford

Baptist Memorial Hospital North Mississippi

South Haven Baptist Memorial Hospital Desoto

Corinth Magnolia Regional Health Center

Vicksburg River Region Hospital

Greenville Delta Regional Medical Center

Columbus Baptist Memorial Hospital Golden

Triangle Pascagoula

Singing River Health Systems Gulfport

Gulfport Memorial Hospital McComb

South West Regional Medical Center

EMS Territorial Boundaries Broken

It is imperative for EMS to be able to cross county lines when necessary for reperfusion.

EMS services should cross-cover for adjacent EMS in another county.

A “Heart Attack” should take priority over many non-life threatening medical conditions.

Goals for STEMI

• First Medical Contact (FMC) to PCI < 90 minutes

• Door to ECG time < 10 minutes

• Door In / Door Out Time < 30 minutes

• FMC to Non-PCI hospital to PCI < 120 minutes

EMS specific

• Ideal for all chest pain patients to have in-field ECG

• Pre-hospital Activation of STEMI network

• Diversion to STEMI hospital 180

Phases of EMS Management of the Stroke Patient

• Activation of 911 system

• EMS response

• On scene assessment and stabilization

• Selection of appropriate destination

• Transport

• Pre-arrival stroke alert to receiving emergency department (as early as possible)

• Delivery of patient and information

• PI feedback

Scene Assessment

• General assessment – Consider alternative causes of neurologic deficit

• Focused neurologic assessment to include FAST – Face

– Arm

– Speech

– Time

• Sensitivity 80%/specificity 30%

• Time of onset - may not be available at hospital

Treatment

• Stabilization

– Standard protocols (check vital signs, ECG, glucose, hydration and treat as needed)

– Scene time should be minimized but prehospital care should not be sacrificed for less scene time

Select Appropriate Destination

• Transport to the nearest hospital with an appropriate level of stroke care – Level may vary as resources change

– Utilize knowledge of local facilities

• Window of opportunity – 4 ½ hours to completion of fibrinolytic treatment (earlier more effective than later)

• Useful time – 3 ½ hours until time of arrival at stroke capable hospital

EMS Goals for Stroke

1) Initial assessment, transport ASAP:

ABCs ; Obtain time of symptom onset (Last time known well) _______; Source of information ________; Contact information _________.

2) Administer high concentration oxygen, as needed, to maintain O2 Sat >94 percent.

3) Position patient with head/shoulders elevated to 15-30 degrees (unless contraindicated).

4) Maintain NPO.

5) Blood glucose < 60, treat per protocol.

6) Do not treat high blood pressure without physician approval.

7) Perform Stroke Scale – Cincinnati Stroke Scale.

8) Transport patient to the appropriate facility:

a. Transport patient to the closest hospital capable of treating the patient with IV Alteplase (Stroke Capable or Primary/Comprehensive Stroke Center). Hospitals not able to diagnose and treat stroke patients (Level 4 hospitals) may be by-passed. EMS may use discretion based on transport time or other unforeseen factors.

b. Consider transport of the stroke patient with severe symptoms (hemiplegia, aphasia, neglect, stably intubated) to a Comprehensive Stroke Center if symptom onset to hospital arrival time is greater than 3 hours and less than 6 hours.

c. Transport patient to the closest appropriate facility if unstable (e.g., cardiac arrest, unstable airway).

9) IV NS KVO once en route.

10) EKG once en route.

11) Notify receiving facility of estimated arrival time of acute stroke patient, Stroke Scale finding, and time of onset. 187

Section 6

EMS Cardiac

Pharmacology

Oxygen

• Indications

– Any suspected cardiopulmonary emergency

– Saturate hemoglobin with oxygen

– Reduce anxiety & further damage

– Note: Pulse oximetry should be monitored

Oxygen

• Precautions

– Pulse oximetry inaccurate in:

• Low cardiac output

• Vasoconstriction

• Hypothermia

– NEVER rely on pulse oximetry!

– Too much oxygen can make some patients with emphysema quit breathing

Aspirin

• Indications

– Administer to all patients with ACS, particularly reperfusion candidates

• Give 325 mg as soon as possible, non-coated preferred

– Blocks formation of thromboxane A2, which causes platelets to aggregate

Anti-Platelet Actions

Aspirin

• Precautions

– Many patients are allergic to aspirin – be sure to ask!

– Does not provide blood thinning effects in all people (aspirin resistance)

– Relatively contraindicated in patients with active bleeding

Thienopyridines (Brilinta, Effient,Plavix)

• Indications

– Use as a second anti-platelet agent in patients with ACS, particularly reperfusion candidates

– Blocks ADP activation of platelets

– Usually given as a bolus dose

• Brilinta – 180 mg (MHCA preferred agent)

• Plavix (clopidogrel) – 600 mg

• Effient – 60 mg

Thienopyridine

• Precautions

– Plavix does not provide blood thinning effects in all people (plavix resistance)

– Effient should not be given to patients with previous stroke or TIA

– Relatively contraindicated in patients with active bleeding

Glycoprotein IIb/IIIa Inhibitors

• Indications

– Inhibit the glycoprotein IIb/IIIa receptor in the membrane of platelets, inhibiting platelet aggregation

– Can be used as an early second anti-platelet agent rather than thienopyridines, especially in those who can’t swallow or have nausea and vomiting.

• Eptifibatide (integrilin)

– Within 10 minutes after bolus, > 90% of platelets are inhibited

– Platelet function recovers within 4 to 8 hours after discontinuation

– Dose

• 180 mcg/kg IV bolus, then 2 mcg/kg/min infusion

• Precautions

– Integrilin (eptifibatide) is a derivative of snake venom

– Use in precaution in those patients with previous snake bites

Heparin

• Indications

– Inhibits thrombin generation by factor Xa inhibition and also inhibit thrombin indirectly by formation of a complex with antithrombin III

– Exists in two forms

• Unfractionated

• Low molecular weight

Unfractionated Heparin

• Dosing

– Initial bolus 60 IU/kg

• Maximum bolus: 4000 IU

• Check efficacy of dose with ACT

• Not always effective

– Continuous infusion at 800-1200 units/hour

Low Molecular Weight Heparin Lovenox (enoxaparin)

• Dosing in ACS in those proceeding to PCI or to receive thrombolytics

– 30 mg IV

• Bolus is active for 3 hours

• Initial dosing in medically treated patients

– 1 mg/kg SQ

• Dose is active for 12 hours

Heparins

• Precautions

– Contraindications: active bleeding; recent intracranial, intraspinal or eye surgery; severe hypertension; bleeding disorders; gastroinintestinal bleeding

– DO NOT use if platelet count is below 100 000

Nitroglycerin

• Indications

– Chest pain of suspected cardiac origin

– Unstable angina

– Complications of AMI, including congestive heart failure, left ventricular failure

– Hypertensive crisis or urgency with chest pain

Nitroglycerin

• What it does…

– Decreases pain of ischemia

– Increases venous dilation

– Decreases venous blood return to heart

– Decreases preload and cardiac oxygen consumption

– Dilates coronary arteries

– Increases cardiac collateral flow

Nitroglycerin

• What it does NOT do…

– Prevent heart attacks

– Save lives

– Limit infarct size

Nitroglycerin

• Dosing – Sublingual Route

• 0.3 to 0.4 mg; repeat every 5 minutes

– Aerosol Spray • Spray for 0.5 to 1.0 second at 5 minute intervals

– IV Infusion • Infuse at 10 to 20 µg/min

• Route of choice for emergencies

• Titrate to effect

Nitroglycerin

• Precautions

– Use extreme caution if systolic BP <90 mm Hg

– Use extreme caution in Inferior and/or RV infarctions – Suspect RV infarction with inferior ST changes

– Limit BP drop to 10% if patient is normotensive

– Limit BP drop to 30% if patient is hypertensive

– Watch for headache, drop in BP, syncope, tachycardia

– Tell patient to sit or lie down during administration

Morphine Sulfate

• Indications

– Chest pain and anxiety associated with AMI or cardiac ischemia

– Acute cardiogenic pulmonary edema (if blood pressure is adequate)

Morphine Sulfate

• Dosing

– 1 to 4 mg IV (over 1 to 5 minutes) every 5 to 10 minutes as needed

Morphine Sulfate

• Precautions

– Administer slowly and titrate to effect

– May compromise respiration; therefore use with caution in acute pulmonary edema

– Causes hypotension in volume-depleted patients

Fibrinolytics

• Indications

– For AMI in adults

• ST elevation or new or presumably new LBBB; strongly suspicious for injury

• Time of onset of symptoms < 12 hours

– For strokes in adelts

• Time of onset of symptoms< 4.5 hours

Fibrinolytics

• Dosing

– For fibrinolytic use, all patients should have 2 peripheral IV lines

• 1 line exclusively for fibrinolytic administration

Fibrinolytics

• Dosing for AMI Patients – Tenecteplase (TNKase)

• Bolus 30 to 50 mg

– Alteplase, recombinant (tPA) • Accelerated Infusion

– 15 mg IV bolus – Then 0.75 mg/kg over the next 30 minutes

» Not to exceed 50 mg – Then 0.5 mg/kg over the next 60 minutes

» Not to exceed 35 mg

Fibrinolytics

• Dosing for Acute Ischemic Stroke – Alteplase, recombinant (tPA)

• Give 0.9 mg/kg (maximum 90 mg) infused over 60 minutes – Give 10% of total dose as an initial IV bolus over 1 minute

– Give the remaining 90% over the next 60 minutes

– Alteplase is the only agent approved for use in Ischemic Stroke patients

Fibrinolytics

• Precautions

– Specific Exclusion Criteria

• Active internal bleeding (except mensus) within 21 days

• History of CVA, intracranial, or intraspinal within 3 months

• Major trauma or serious injury within 14 days

• Aortic dissection

• Severe uncontrolled hypertension

Fibrinolytics

• Precautions

– Specific Exclusion Criteria

• Known bleeding disorders

• Prolonged CPR with evidence of thoracic trauma

• Lumbar puncture within 7 days

• Recent arterial puncture at noncompressible site

• During the first 24 hours of fibrinolytic therapy for ischemic stroke, do not give aspirin or heparin

Amiodarone

• Indications

– Powerful anti-arrhythmic with activity in both atria and ventricles; so that, this drug can be used for atrial fibrillation and VT

– Can be used to prevent recurrent VF

Amiodarone

• Dosing

– 150 mg bolus dose

• May repeat x 1

– Can also use continual IV infusion

• 1 mg/min x 6 hours, then

• 0.5 mg/min

Amiodarone

• Precautions

– May produce vasodilation & hypotension

– May have negative inotropic effects

– Terminal elimination

• IV half-life lasts hours

• Oral half-life lasts up to 40 days

Lidocaine

• Indications

– VT

– Vfib

– Frequent PVCs

Lidocaine

• Bolus Dosing – Initial dose: 1.0 to 1.5 mg/kg bolus IV

– May repeat bolus x 1 for refractory VF

– May also be given down ET tube

• Maintenance Infusion – 2 to 4 mg/min IV continuous infusion

Lidocaine

• Precautions

– Reduce maintenance dose (not loading dose) in presence of impaired liver function or left ventricular dysfunction

– Discontinue infusion immediately if signs of toxicity (seizures, confusion) develop

Atropine Sulfate

• Indications

– Should only be used for bradycardia

• Relative or Absolute

– Used to increase heart rate

Atropine Sulfate

• Dosing – 1 mg IV push

– Repeat every 3 to 5 minutes

– May give via ET tube (2 to 2.5 mg) diluted in 10 mL of NS

Atropine Sulfate

• Precautions

– Increases myocardial oxygen demand

– May result in unwanted tachycardia or dysrhythmia

– When given in low doses (<0.4 mg), can cause a paradoxical bradycardia

Dopamine

• Indications

– Second drug for symptomatic bradycardia (after atropine)

– Use for hypotension (systolic BP 70 to 100 mm Hg) with S/S of shock

Dopamine

• Dosing

– IV Infusions (Titrate to Effect)

• Low Dose “Renal Dose" – 1 to 5 µg/kg per minute

• Moderate Dose “Cardiac Dose" – 5 to 10 µg/kg per minute

• High Dose “Vasopressor Dose" – 10 to 20 µg/kg per minute

Dopamine

• Precautions – May use in patients with hypovolemia but only after

volume replacement

– May cause tachyarrhythmias, excessive vasoconstriction

– DO NOT mix with sodium bicarbonate

Epinephrine

• Indications

– Increases:

• Heart rate

• Force of contraction

• Conduction velocity

– Peripheral vasoconstriction (raises blood pressure)

– Bronchial dilation

Epinephrine

• Dosing

– 1 mg IV push; may repeat every 3 to 5 minutes

– May use higher doses (0.2 mg/kg) if lower dose is not effective

– Endotracheal Route

• 2.0 to 2.5 mg diluted in 10 mL normal saline

– Profound Bradycardia

• 2 to 10 µg/min infusion (add 1 mg of 1:1000 to 500 mL normal saline; infuse at 1 to 5 mL/min)

Epinephrine

• Precautions

– Raising blood pressure and increasing heart rate may cause myocardial ischemia, angina, and increased myocardial oxygen demand

– Do not mix or give with alkaline solutions

– Higher doses have not improved outcome & may cause myocardial dysfunction

Diltiazem

• Indications

– To control ventricular rate in atrial fibrillation and atrial flutter

– Use after adenosine to treat refractory PSVT in patients with narrow QRS complex and adequate blood pressure

Diltiazem

• Dosing

– Acute Rate Control

• 10 to 20 mg (0.25 mg/kg) IV over 2 minutes

• May repeat in 15 minutes at 20 to 25 mg (0.35 mg/kg) over 2 minutes

– Maintenance Infusion

• 5 to 15 mg/hour, titrated to heart rate

Diltiazem

• Precautions – Do not use calcium channel blockers for tachycardias of

uncertain origin

– Avoid calcium channel blockers in patients with Wolff-Parkinson-White syndrome, in patients with sick sinus syndrome, or in patients with AV block without a pacemaker

– Expect blood pressure drop resulting from peripheral vasodilation

– Concurrent IV administration with IV ß-blockers can cause severe hypotension or heart block

Question 1

• Which of the following is an adverse reaction to nitroglycerin? A) Hypertension B) Hypotension C) Lacrimation D) Arrhythmias

Question 1

• Which of the following is an adverse reaction to nitroglycerin? A) Hypertension B) Hypotension C) Lacrimation D) Arrhythmias

Question 2

• Which of the following must be given within 4.5 hours of the beginning of a stroke?

A. Thrombolytics

B. Anti-platelets

C. Heparin

Question 2

• Which of the following must be given within 4.5 hours of the beginning of a stroke?

A. Thrombolytics

B. Anti-platelets

C. Heparin

Question 3

• Which of the following agents is most efficacious in the conversion of acute AF into sinus rhythm?

a. Metoprolol

b. Digoxin

c. Amiodarone

d. Diltiazem

e. Esmolol

Question 3

• Which of the following agents is most efficacious in the conversion of acute AF into sinus rhythm?

a. Metoprolol

b. Digoxin

c. Amiodarone

d. Diltiazem

e. Esmolol

Question 4

• The following are true for aspirin, except:

a. Aspirin is indicated in combination with warfarin in patients at high risk for mechanical valve thrombosis

b. Clopidogrel should be administered to aspirin-intolerant patients acutely with an STEMI

c. Aspirin is indicated in acute thrombotic stroke

d. Aspirin is FDA approved for primary prevention of MI.

Question 4

• The following are true for aspirin, except:

a. Aspirin is indicated in combination with warfarin in patients at high risk for mechanical valve thrombosis

b. Clopidogrel should be administered to aspirin-intolerant patients acutely with an STEMI

c. Aspirin is indicated in acute thrombotic stroke

d. Aspirin is FDA approved for primary prevention of MI.

Question 5

• Appropriate upfront medical therapy in a previously healthy 51 year old man having a STEMI includes all of the following except:

a. Aspirin

b. Heparin

c. Lipitor

d. Brilinta

Question 5

• Appropriate upfront medical therapy in a previously healthy 51 year old man having a STEMI includes all of the following except:

a. Aspirin

b. Heparin

c. Lipitor

d. Brilinta

CONCLUSIONS

• Be constantly alert—patients can change in seconds

• Know your drugs---use resources

• Remember that every drug, even OTC drugs, have the potential to result in a serious adverse reaction

CONCLUSIONS

• Never leave the sending facility unless you feel thoroughly comfortable with your patient and with the medications you are being asked to administer or monitor

• Make sure that you are thoroughly prepared for any complication

• Know where possible diversion hospitals are located

• Use your EMS medical director whenever necessary

CONCLUSIONS

Questions?

The End

• Thank you for your time today in learning the interpretation of ECGs.

• With your new knowledge and proficiencies, patients of Mississippi are in better hands.

12 Lead EKG Interpretation

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