stemi, n-stemi, and everything else

ACP Academy Section 5: Advanced Clinical Education Cardiology

STEMI, N-STEMI, and everything else

Ada County Paramedics Block Training

April 2008


Contact Information

• Ada County Paramedics– 5870 Glenwood– Boise, ID 83714– Adaparamedics.org– 208-287-2972


• Credit where Credit is due:– Ada County Paramedics:

• Douglas Jay for his donation of materials as well as time.• Jason Creamer, and Jeremy Schabot, both for their time,

and their tireless devotion to raising the bar for paramedics everywhere.

– For Donation of materials and motivation:• Hilton Head F&R, SC: Tom Bouthillet, Lt./NREMT-P• Witham Health Services, Indiana: Andrew J. Bowman, MSN,

NREMT-P• Chris Smith, NREMT-P


Focus Statement

• This block of training will focus on Improving STEMI recognition, improving EMS involvement in E2B/D2B programs, and minimizing false STEMI team activations


Disclosure Statement


Terminology

• PH ECG/PH 12 lead: Pre-hospital ECG• PCT: Pre-hospital Cardiac Triage• STEMI: S-T segment Elevation Myocardial

Infarction• N-STEMI: Non S-T segment Elevation

Myocardial Infarction• D2B: Door to Balloon (PTCA)• E2B: EMS to Balloon• SRC: STEMI Receiving Center

– (Primary PCI capable with surgical capability)


All Hail the Great S-T Segment

(or …all you wanted to know about the ST segment but didn’t

know to ask…)


Understanding the ST segment


Measuring ST ChangesMeasuring ST Changes• Baseline is correctly determined by finding the T-P to T-P

segment. (If TP not measureable, then preceeding P-R interval can be used.)

• ST changes are measured 0.08 sec after the “J-point”.• Changes must be present in 2 or more leads of a “lead group”

to be significant.• ST elevation or depression of 1 mm or greater in frontal plane

leads is considered significant.• ST elevation or depression of 2mm or greater in precordial

leads is considered significant.• ST elevation of 0.5mm or greater in R precordial leads is

considered significant.


T-wave Changes in IschemiaT-wave Changes in Ischemia

• Appear within seconds of onset of AMI• Appear over zone of ischemia• May be tall and or deeply inverted depending

on location of ischemia• Symmetry is important finding in ischemia• Are associated with prolonged QT interval• Often associated with ST depression• Rapidly revert to normal after anginal attack• Persist in q-wave infarct.


T-Wave Changes in IschemiaT-Wave Changes in Ischemia

Peaked, Symmetrical T-WavesPeaked, Symmetrical T-Waves


T-wave changes in IschemiaT-wave changes in Ischemia

Inverted T-wavesInverted T-waves


T-Wave Changes In IschemiaT-Wave Changes In Ischemia

Tall, symmetrical T-Waves With ST ElevationTall, symmetrical T-Waves With ST Elevation


ST Depression in IschemiaST Depression in Ischemia• ST depression is a sign of myocardial ischemia

and can appear in setting of ischemia from any cause.

• Onset is usually within first hour of AMI, or more rapidly in other causes of ischemia.

• Often associated with T-wave changes• Can resolved rapidly with reversal of ischemia.• May persist in setting of AMI.• Mimics include: Coronary artery spasm, acute

pericarditis, ventricular aneurysm.


Types of ST DepressionTypes of ST Depression


ST Elevation in AMIST Elevation in AMI

• Abnormal ST elevation is an ECG sign of Abnormal ST elevation is an ECG sign of myocardial injury.myocardial injury.• Usually occur Usually occur within 20-40minuteswithin 20-40minutes following onset of following onset of

infarction.infarction.• Changes in diastolic resting potential of injured cells Changes in diastolic resting potential of injured cells

causes downward shift of T-Q interval.causes downward shift of T-Q interval.• As AMI progresses ST elevation begins returning to As AMI progresses ST elevation begins returning to

baseline, as Q waves and flipped T-waves develop.baseline, as Q waves and flipped T-waves develop.

• ST Elevation mimics: pericarditis, early ST Elevation mimics: pericarditis, early repolarization, LVH with strain pattern.repolarization, LVH with strain pattern.


Reciprocal Changes?• Reciprocal ST segment

depression: In the setting of STE AMI, ST segment depression located in leads distant from the infarction is termed reciprocal change or reciprocal ST segment depression.

• Reciprocal change is useful – diagnostically— its presence strongly

suggests AMI– prognostically— patients with such a

finding have larger infarcts, lower resultant ejection fractions, and higher rates of death.

• Sometimes hard to differentiate form ST depression


S-T changes and their location?


Cardiac Anatomy in Relation to Coronary Artery

Cardiac Anatomy in Relation to Coronary Artery

Rightcoronary

artery

Septal wallV1-V2

Left anterior descending artery

Anterior wallV3-V4

Left main coronary artery

Circumflex artery

Lateral wallI, aVL, V5-V6


Associations Between Changes on12-Lead ECG and Cardiac AnatomyAssociations Between Changes on12-Lead ECG and Cardiac Anatomy

aVF inferiorIII inferior V3 anterior V6 lateral

aVL lateralII inferior V2 septal V5 lateral

aVRI lateral V1 septal V4 anterior


Inferior MI Localization

aVF inferior

III inferior

V3 anterior

V6 lateral

aVL lateral

II inferior V2 septal V5 lateral

aVRI lateral V1 septal V4

anterior


Lateral MI Localization

aVF inferior

III inferior

V3 anterior

V6 lateral

aVL lateral



anterior


Lateral MI


Septal MI Localization

aVF inferior

III inferior

V3 anterior

V6 lateral

aVL lateral



anterior


Inferior MI Localization

aVF inferior

III inferior

V3 anterior

V6 lateral

aVL lateral



anterior


Inferior MI


NOTE 1: Inferior wall supplied by either the right (85% to 90% of people) or left coronary artery.

NOTE 2: If there is acute injury in inferior leads (II, III, aVF), unknown whether left or right coronary artery is blocked.

NOTE 3: KEY — you must obtain a RIGHT-RIGHT-SIDED ECGSIDED ECG at once.

Posterior View of the HeartPosterior View of the Heart

HOW TO GET HOW TO GET RIGHT-SIDED ECG?RIGHT-SIDED ECG?

Leads II, III, aVF

(from left left coronary coronary arteryartery)

Lateral wall

Inferior wall

Right coronary Right coronary arteryartery

Posterior descending

artery

Posterior wall

Circumflexartery


Right Ventricular InfarctionRight Ventricular Infarction

• Inferior lead changes RV infarction?–Use lead V4R (ST elevation >1 mm)

• Clinical significance:–Increased mortality–Preload dependencePreload dependence

• Vasodilators (Nitrates, MSO4Nitrates, MSO4) may cause severe hypotension

• What is management of RV infarction?–Increase PRELOAD!! (FLUIDS)Increase PRELOAD!! (FLUIDS)


STEMI, N-STEMI, and STEMI Mimics


Three “I”s

• Ischemia

• Injury

• Infarction


ACUTE CORONARY SYNDROMES

No ST elevation ST elevation

Unstableangina

NSTEMI STEMI

Spectrum of CAD

Stableangina

Source (Photos): Davies MJ. Heart. 2000;83:361-366.

CAD = coronary artery disease; NSTEMI = non-ST-segment elevation myocardial infarction;STEMI = ST-segment-elevation myocardial infarction.


What is STEMI?

• S-TS-T EElevation MMyocardial Infarction– Can we measure the ST segment accurately?– What does the ST segment look like?

• WE CANT CALL A CODE STEMI IF WE DON’T KNOW HOW TO EVALUATE AN ST SEGMENT


N-STEMI?

• N-STEMI is an MI that does not show ST elevation

• You cannot call an N-STEMI a STEMI, regardless of how strongly you suspect the MI.

• You can call “Medical Stat” (Discussed later)


STEMI Mimics

• Things that make you go … HMMMM

• Things that look (at first glance) Like a STEMI or other MI pattern, but are NOT.

• Thinks that will cause you to INAPPROPRIATELY call a Code STEMI– Increase “false positive rates”

• Still may be deadly serious conditions


The basics of doing the 12 lead


The Basic 12 Lead


Lead Placement for a Right-sided ECG

Lead Placement for a Right-sided ECG


The Right Ventricular LeadsThe Right Ventricular Leads


KEY POINT!

• BE SURE TO WRITE ON ECG THAT IT WAS A RIGHT SIDED ECG!


Posterior ECG?


The importance of serial 12 leads


STEMI MIMICS


Most common causes of STEMI mistakes

• RBBB/LBBB

• Pericarditis

• LVH

• Electrolyte Imbalances

• Drug Effects


Bundle Branch/Fascicular Bundle Branch/Fascicular BlocksBlocks

• LBBB always indicates cardiac disease or injury.• Just not always ACUTE injury• Just not always MI, other “Mimics” can also cause

BBB

• “Making the diagnosis of acute infarction in the presence of left bundle-branch block can be problematic…”– PROBLEM: Patients with (suspected new)

LBBB tend to be REALLY BAD MI’s.


Bundle Branch/Fascicular Blocks Right Bundle Branch Block

• Do not rely on presence of “rabbit ears” for Do not rely on presence of “rabbit ears” for diagnosis of RBBB. Will miss many RBBBs.diagnosis of RBBB. Will miss many RBBBs.


AMI with BB? AMI with BB? • AMI should be no problemAMI should be no problem

• RBBB does not change S-T segment RBBB does not change S-T segment alterationsalterations

• LBBB can make things more interestingLBBB can make things more interesting


Again with the serial ECGs???

• Even though the LBBB makes initial ST evaluation difficult, the serial changes noted make this diagnostic for MI.


STEMI MimicsSTEMI Mimics• PericarditisPericarditis

1.1. No reciprocal changes. There will only be No reciprocal changes. There will only be S-T elevation, no depression.S-T elevation, no depression.

2.2. The myocardium is not involved. No The myocardium is not involved. No changes will be noted to the QRS complex.changes will be noted to the QRS complex.

3.3. Changes isolated to the S-T-T wavesChanges isolated to the S-T-T waves


STEMI MimicsSTEMI Mimics• Pericardial EffusionPericardial Effusion

1.1. Distinctive patternDistinctive pattern

2.2. Changing polarity of Changing polarity of Q-R-SQ-R-S


STEMI MimicsSTEMI Mimics• HyperkalemiaHyperkalemia

– Progressive changes to de- & repolarizationProgressive changes to de- & repolarization– T wave peaks, then widens/flattensT wave peaks, then widens/flattens– PR interval prolongs, and P wave flattensPR interval prolongs, and P wave flattens– QRS widens alsoQRS widens also


Potassium Level: 6.1 mEq/L


STEMI MimicsSTEMI Mimics• HypokalemiaHypokalemia

– ST depression with prominent U-wavesST depression with prominent U-waves– Prolonged repolarizationProlonged repolarization– T waves flattenT waves flatten– Can mimic reciprocal changesCan mimic reciprocal changes


STEMI MimicsSTEMI Mimics• Cardiac Glycosides-DigoxinCardiac Glycosides-Digoxin

– Digitalis effect-”scooped” ST segmentDigitalis effect-”scooped” ST segment

• Anti-dysrhythmic agentsAnti-dysrhythmic agents– Based on where they workBased on where they work– QT prolongation is commonQT prolongation is common

• Psychotropic agents (i.e.TCA’s)Psychotropic agents (i.e.TCA’s)– Increase QRS durationIncrease QRS duration– Lengthen QT intervalLengthen QT interval


STEMI Mimics

• Well, Kinda anyway

• Pacemakers


The Problem

• Research has recognized that half of patients with myocardial infarction do not arrive early enough (90 minutes) to PCI…– Door to Balloon time <90 minutes is a class I

Intervention in STEMI

• Numerous strategies to improve the “Door to Balloon” time have evolved.


The Solution

• New strategies have involved a player previously ignored in cardiac care… EMS!

• Local cardiology groups and hospitals have committed to involving EMS in improving time to PCI!

• This has a direct measurable effect on mortality!!!– Only if the system works and EMS does its

part!


Key to this is Pre-Hospital Cardiac Triage

And accurate 12 lead interpretation!

DON’T TELL ANYONE, BUT EMS HAS BEEN DOING 12 LEADS FOR ALMOST 40 YEARS!!!


First field First field 12 lead12 lead

Seattle Medic OneSeattle Medic One

Circa 1969Circa 1969


WHY 12 leads?

• 12 leads are the KEY to open the DOOR to PCI!!!!!

• PARAMEDICS ARE THE KEYMASTERS• WHO IS THE GATEKEEPER?

– ER Docs– Cardiologist– Bean Counters!!!

• TRUE STORY: EMS has 1 chance to impress and right now that chance is slipping away…


The KEYMASTER and the GATEKEEPER?

12 Leads!!!!12 Leads!!!!


Time to Treatment in PCI(Nallamothu 2007 NEJM 357:1631)

What this means:What this means:Beyond a D2B ≤90 Minutes…Beyond a D2B ≤90 Minutes…

Every 15-minutes of Delay Every 15-minutes of Delay MortalityMortality


Why the big push for PCI?????


D2B Alliance Goal

• “To achieve a door-to-balloon (D2B) time of 90 minutes for at least 75%75% of non-transfer primary PCI patients with ST-elevation myocardial infarction (STEMI) in all participating hospitals performing primary PCI”

• National baseline about 50%50% rate D2B 90 with out systems approach


NEW CONCEPT IN PCI

• No longer just Door to Balloon (D2B)….

• Now EMS to Balloon (E2B)….


Onset of symptoms of

STEMI

9-1-1EMS

dispatch

EMS on-scene

Understanding the Intervals

ACPACP

S2B: S/S Onset to BalloonS2B: S/S Onset to Balloon

E2B: EMS to BalloonE2B: EMS to Balloon

C2B: Call to BalloonC2B: Call to Balloon

D2B:D2B: Door to Balloon

Hospital

BB

AA

LL

LL

OO

OO

NNR2R: Recognition (12 lead) to Re-perfusion


Isn't just doing PH 12 leads enough?

• In a nutshell: NO• Implementation of PH 12 leads by itself did

not significantly impact D2B times.• PH 12 leads only shown to make a

difference in a SYSTEMS/PROTOCOL driven approach– Otherwise the 12 leads gather dust

• Fortunately SARMC/SLRC are interested in a SYSTEM


Pre-hospital Cardiac TriagePre-hospital Cardiac Triage

Similar to nation’s current trauma systems:

sick pts = special care at specialty centers with specialty team activation


30-30-30 GoalE2B≤90 Conceptual Framework

< 30 minutes for Emergency Med Services (EMS)

< 30 minutes for the Emergency Department (ED)

< 30 minutes for the Cardiac Cath Lab (CCL)


EMS Transport <20 min

Onset of symptoms of

STEMI

9-1-1EMS

dispatch

EMS on-scene• Mandatory 12-lead ECGs• TRANSMIT 12-leads

1 minute

PCIcapable

Not PCIcapable

Code STEMI and Rapid CCT Transfer

STEMI TriageHospital Destination

Guidelines

TIME LOST!!!

CCTRequired

BEST PRACTICES : Golden hr = E2B/D2B within 1st 60 min

Total ischemic time for E2B/D2B GOAL: within 120 minTotal ischemic time for E2B/D2B GOAL: within 120 min

Patient EMS

E2B <90 min?: EMS Treat and transport to PCI Capable hospital

Dispatch

????? Time10min

ACP approach for Transport of Patients With STEMI and Initial Reperfusion Treatment

ACPACP

SLRMCSLRMC

SARMCSARMC

SLMMCSLMMCSAEMCSAEMCVAMCVAMCWVMCWVMCMMCMMC

Code STEMI and Direct to PCI

Med STAT- ED MD triage t PCI

ASA?

EMS

PH 12 lead transmission


CODE STEMI is the “Level 1 Trauma” of the Cardiac World

“Medical Stat” is the Level II and Level III


SO WHERE IS ACP?

• 2/2008 review for prior 6 months• Total Charts Reviewed: 88

– CODE STEMI charts reviewed: 28– Other Chest Pain/DX of AMI charts (No Code STEMI called): 60

• 3 charts out the 60 showed STEMI on EMS12 lead

• Results:– Fail to recognize/report rate: 2.6%– Of Code STEMI Called

• STEMI continued at hospital: 21 (75%)• STEMI cancelled: 7 (25%)

• False Negative Rate -2.6%• False Positive rate: -25%

– Goal is 5%


CAN WE DO CAN WE DO BETTER?BETTER?

(and what happens if we don’t???????)


So what's the big deal?

• False Positives: (calling Code STEMI inappropriately) ?– $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$– Urgent and “less emergent” PCI are bumped

for the “code STEMI– Cardiologist taken away from PCI and other

duties– WHOLE SYSTEM GETS ACTIVATED

• If 12 lead is not received, activation continues anyway


So what's the big deal?

• False Negatives: (No Code STEMI Called)– MD does not see 12 lead, it sits and gathers

dust. – Consistently exceeding D2B >90 min– Increased mortality


3 layers of Safety Net

• Cognitive Detection – The paramedic and his 12 lead is a beautiful

thing

• Automated Detection– “*** ACUTE AMI *****”

• Emergency Department Screening– MD review to prevent false positives and to

pick up on STEMI mimics that still need urgent care


3 Levels of Notification

CODE STEMI Medical STAT

Business as UsualRoutine Radio report


Obt

ain

and

Tra

nsm

it 12

lead

Inclusionary Criteria Inclusionary Criteria Suspicion for ACS S/S AND

ST Elevation 2mm in 2+ contiguous Leads Exclusionary Criteria Exclusionary Criteria

NO QRS greater than 0.11 ORNO LBBB

Inclusionary Criteria Inclusionary Criteria Automatic Detection : “Acute MI”

Paramedic DiscretionSuspicion for ACS S/S

AND (Any of the following):Global ST Changes

N-STEMIST Elevation in 1 mm in Inferior Leads

ST Depression or Inverted Ts in contiguous leads Questionable Reciprocal Changes

Presumed New LBBBInverted T-Waves or ST depression in 2+ contiguous leads

Hyper-acute T waves present in 2+ contiguous leads.Exclusionary Criteria Exclusionary Criteria

NONE

CODE STEMI

Medical STAT

PH ECG Eval

Radio Report

Radio Report

Proposed ACP protocol to reduce E2BProposed ACP protocol to reduce E2B


Medical State

• Medical State can also be used on other time sensitive emergencies…– Respiratory Failure with CPAP– Field ETT placed– “RT at bedside”– “MD at bedside”


Closing Thoughts

“However, it is becoming increasingly clear that the emergency medical services (EMS) have an important role in STEMI patient care, and that a three-way partnership involving EMS, EM departments, and the CCL has substantial potential to increase access to PCI for STEMI and simultaneously reduce door-toballoon times.”

Tom Bouthillet, FF/NREMT–P

STEMISystems, Issue 2, May 2007


STEMI, Medical SAT, or Other?

Click for answer



• 26 y/o male presenting to EMS after arrest for probation violation.

• He is in booking, suddenly complains of chest discomfort.

• EMS is notified.

• Smokes a pack a week approx for 3 years

• No other history

• No reported drug use/abuse


STEMI, Medical SAT, or Other?STEMI, Medical SAT, or Other?



Click for answer



• 45 y/o male with chest pain, nausea, vomiting, and dizziness while in bed.

• B/P 80/40

• HR regular and tachycardic

• Has not been to a doctor since he was in the army 20 years previous

• Notably obese. Smokes


On final unrelated thought

• A recent review showed that less than 5% of patients who received NTG SL by ACP received NTG Paste in follow up.

• The benefits of NTG paste are significant– You don’t have to do a full 3 doses to initiate

it.

• Please consider it in the future.


Now for Hands on…Now for Hands on…

• Entering Names

• Right sided and posterior 12 lead placement

• Transmission of 12 leads

• Scenarios?