The ACLS Cases: Acute Coronary Syndromes

Acute Coronary Syndromes Case

Introduction The ACLS provider must have the basic knowledge to assess and stabilize patients with
ACS Patients in this case have Signs and symptoms of ACSr including possible AML You
will use the ACS Algorithm as the guide to clinical strategy.

-
The initial 12 lead EGG is used in all ACS cases to classify patients into 1 of 3 ECG cat
egones each with different strategies of care anc management needs These 3 ECG cat -
-
egories are ST ssgfnent elevation suggesting ongoing acute injury . ST- segment depression
suggesting ischemia and nondiagnostic or normal ECG. These are outlined in the ACS
,

Algorithm, but STEM! with time sensitive reperfusion strategies is the focus of this course
(Figure 20).

Key components of this case are

* Identification, assessment , and triage of acute ischemic chest discomfort

* Initial treatment of possible ACS
* Emphasis on early reperfusion of the patient with AGS/STEMl:

Rhythms for ACS Sudden cardiac death and hypotensive bradyarrhythmias may occur with acute ischemia
Providers will understand to anticipate these rhythms and be prepared for immediate
attempts at defibnliation and administration of drug or electrical therapy for symptomatic
bradyarrhythmias.

Although 12 - lead ECG interpretation is beyond the scope of the ACLS Provider Course ,
some ACLS providers will have 12 - lead ECG reading skills For Ihem, this case summa-
rizes the identification and management of patients with STEMl

Drugs for ACS Drug therapy and treatment strategies continue to evolve rapidly in the field of ACS. ACLS
providers and instructors will need to monitor important changes The ACLS Provider
Course presents only basic know ledge focusing on early treatment and the priority of
rapid reperfusion, relief of ischemic pain, and treatment of early life - threatening complica
.
lions Reperfusion may involve the use of fibrinolytic therapy or coronary angiography with
PCI (ie . balloon angioplasty/stenting), When used as the initial reperfusion strategy for
STEML PCI rs called primary PC / .

Treatment of ACS involves the initial use of drugs to relieve ischemic discomfort , dissolve
clots , ind inhibit thrombin and platelets. These drugs are

* Oxygen
* Aspirin
* Nitroglycerin
Opiates (eg, morphine)
* Fibrinolytic therapy (overview)
* Heparin (UFH. LWMH)
Additional agents that are adiunctive to initial therapy and will not be discussed in she
ACLS Provider Course are
* 0 - Blockers
.
* Adenosine diphosphate (ADR ) antagonists (dopidogrel prasugrel, fccagrelor )
* Angiotensin-converting enzyme ( ACE) inhibitors
* HMG -GoA reductase inhibitors ( statin therapy )
* Glycoprotein llb/ Wa inhibitors

59
 P a r t

Goals for ACS Patients

Foundational Facts OHCA Response

H Half of the patients who die ot ACS do so before reaching the hospital VF or pulseless
VT is the precipitating rhythm in most of these deaths , VF is most likely to develop dur -
ing Ihe first 4 hours after onset of symptoms.

Communities snould de \ * Top programs to

focus on
respond to OHCA Such programs should

* Recognizing symptoms of ACS

* Activating the EMS system, with EMS advance notification ol the receiving hospital
* Providing early CPR
* Providing early defibnilutron with AEDs available through publ# c access defibrination
programs and first responders
* Providing a coordinated system of care among the EMS system, the ED and
Cardiology

The primary goals are

* Identification of patients with STEMI and triage for early reperfusion therapy
* Relief of ischemic chest discomfort
.
* Prevention of MACE such as death, nonfatal Ml and The need for urgent post infarc -
,

tion revascularization
* Treatment of acute life - threatening complications of ACS . such as VF - pulseiess VT ,
symptomatic bradycardias , and unstable tachycardias
Reperfusion thefapy opens an occluded coronary artery with either mechanical means or
drugs PCI performed m Ihe heart cathetenzation suite after coronary angiography, allows
balloon dilation and/ or stem placement for an occluded coronary artery. “Clot - buster '1
drugs are called fibrinolytics , a more accurate term than ihrombofytics.

Pa thophys iol ogy Patients with coronary atherosclerosis may develop a spectrum of clinical syndromes rep
of ACS resenting varying; degrees of coronary artery occlusion These syndromes include non - ST
.
elevation ACS (NSTE - AQS) and STEMI Sudden cardiac death may occur with each ol
these syndromes . Figure 19 illustrates the pathophysiolog-., of ACS

GO
 77ie ACLS Cases: Acute Coronary Syndromes

A Unstable plaque
Early plaque formation
B Plaque rupture
C Unstable angina
D Mrcroemboli
E Occlusive thrombus
Significant plaque formation

Plaque rupture/ thrombus

NSTE- ACS

I
STEMI
Resoiution/ stabie angina

Figure 1 Pathophysiology ctf AGS

61
 P a r t

Acute Coronary Syndromes Algorithm- 2015 Update

i

Symptoms of uchamUi or infarction

2 j
EM5 iMimmeni and care and hpepiLal preparation
*Mor -tor supper " AJ-lCs 13a prepared 1o prowl* in CHR and datfibrillatien
* Arjrnir:;stfr aspirin and eorader oxygen riltraglv^wrin. ar d mwprun* ir weted
* Obtain ? 2-:sad ECO 1 5 r fltivaeionj
-
- Notify ^^OCMV r g hcstpitaJ wiUn tanarnflt^bn g* iarprefcaran not # iim# of
onset and fins ccrj: d

* Mea&ed hoppM w>, 3 iKt = tKxpc\a

*
to respond to STB1
i
if ov&Mtm pmhoipfl ' ftonno ti, m fiti nutyiiG c ck:
* ^ ^
.
3 J
Goncurranf ED assessmanrt ( flip minuta)
* Clue MTtJti ugns. evaluate osygon sarturaton
*
- Immaehafa ED general treatment
* W 0 } ut 90% -Stan Bifvtft & L/
-
K
r
* . Ertrate
, -
* EvtattfuftlV access * AfiMm 160 to 325 mg •* • * % *** dy EM5
*
- Hbnnqlytc ohacMai
* PeHtanr, i rvef ^ geled
*
,> : •
istar' * Hftrogfycerin sub" Tigwil V pr y
* *
* nOhKh conSrafKj
wrtnonyiH . * Miorpfim fn i n - scon 3 no tortured tty
(Mngtinftn *
^l*pns
* Otoi*n WtiflJ car&at mart- ! * IBVIIIHU -
mlflial
' jiuctfo - yle ar-d coagulant *n ‘*1* dfos
* Obtwn pOflatole ches? x f flv l * 30 minu osl
--
4 a
ECG intefpfetation

5
I
ST alevel on or now nr
9

ST depression nr dynamic
\S
11

Normal or Pond gnD lu cfwn >gas in

presumably ne* L0B8 . T-MMSV rveroion. itrongly * *
*
St ^pgrnsni gr T wave
. *
atrang v MDClM tv njury
* lor Lottf - /interrTM<A t»-ritft ACS
sr- ef vati&n M / prFAJIJ ' suspicious
AC$ *
* (KSTE-AC& }
6 , \

* Stan adjunctive ( tompifrt 10 12

aa indicated
* Do not delay rop rtu»ion * Troponin elevated1 or higih-riafc patient Consider acfml-ulon to
Cofuidef eariy bfWHivt strategy it; ED Chttt pain unrt M ia
_
* fttlracir^V sEhamc Cheil adOdmfcut appropriate bed for
7 > 12 * Ri . -
r uneic pntslenl S *
'
further monitoring and:
fv& wr * yanincut ; - ’actrysaria pc s s bl« (Ptam-nf * B I
*
Tan from of *
< symptom * slS hpura? * * Homodynarnc rnjtftf
* S gne of r jn ta jre
,

* *
Start .adjunctive Uhefapiet *
eg . niinoglyoerin, hepfiml an imftulad

&
iiJ hour
* -
boo AHA ACC MSTE’ACS CkJidHin
^
Reperruakm gowi
*
Thanpy Osflned by paf ^t mcj .
* -
£ 1«r c-' er.e
^
-
* Door-ig bafoon irritation
fPCfl goal of 90 mioul^a
-
* Duor-io ncedle Jfibnnnf stsl
goal of 30 vnlnutes ^
O 1* 115
* Airier can *ar:-:-- al>
-n
Figure 20, Tt n Acute Cortmary SyndiQfiiffi AJgonlftm

Managing ACS; The Acute Coronary Syndromes Algorithm

Overview of The Acute Coronary Syndromes Algorithm fFigure 20 j outlines the assessment and man
the Algorithm agement steps for a patient presenting with symptoms suggestive of ACS. The EMS
responder m the out of -hospital environment can begin immediate assessments and
actions , These include giving oxygen, aspirin, nitroglycerin, and morphine if needed, and
obtaining an inillaI 12 - lead ECG (Step 2 ) , Based on Ihe ECG findings, the EMS provider
may complete a fibrinolytic therapy checklist and notify the receiving ED of a potential
62
 The ACLS Cases: Acute Coronary Syndromes

AMI- STEMl when appropriate (Step 3) , If out - of - hospital providers are unable to complete
These initial sleps before the patient 's arrival at the hospital, the ED provider should imple-
ment this component of care

Subsequent treatment occurs on the patient ’s arrival at the hospital., ED personnel should
review the out -of hospital 12 lead EGG if available. It not performed. acquisition of the
12 - lead EGG should be a priority. The goal is to analyze the 12 - lead EGG as soon as pos ^

sib ]e within 10 minutes of the patients arrival in The ED (Step 4 ). Hospital personnel should
categorize patients into 1 of 3 groups according to analysts of the ST segment or the
presence of left bundle branch block (LBBB) on the 12-lead ECG. Treatment recommen -
dations are specific to each group,

* STEMI
* NSTIE - ACS
* Low - / intermediate - risk AGS
The ACS Case will focus on the early reperfusion of the STEMl patient , emphasizing initial
care and rapid inage for reperfusion therapy

Important
Considerations
-
The ACS Algorithm (Figure 20 provides general guidelines that apply to the initial triage
-
of patients based on symptoms and the 12 lead EGG. Healthcare personnel often obtain
.
serial cardiac markers ( CK -MB cardiac troponins) in most patients that allow additional
risk stratification and treatment recommendations. Two important points for STEM! need
emphasis:

* The ECG is central to the initial risk and treatment stratification process .
• Healthcare personnel do not need evidence of elevated cardiac markers to make a
decision to administer fibrinolytic therapy or perform diagnostic coronary angiography
with coronary intervention (angioplasty /stenting) in STEM! patients.

Application of the The steps in the algorithm guide assessment and treatment
ACS Algorithm • Identification of chest discomfort; suggestive of ischemia (Step 1)
• EMS assessment, care , transport and hospital prearrival notification (Step 2)
,

• Immediate ED assessment and treatmeni (Step 3 )

• Classification of patients according to ST segment analysis (Steps 5, 9 , and 11)
• STEMl (Steps 5 through 8)

Identification of Chest Discomfort Suggestive of Ischemia

You should know how to identify chest discomfort suggestive o ischemia. Conduct a prompt
Signs and
Conditions
*
and targeted evaluation of every patient whose initial complaints suggest possible ACS.

The most common symptom of myocardial ischemia and infarction is retrosternal chest
discomfort The patient may perceive this discomfort more as pressure or tightness lhan
actual pain.

Symptoms suggestive of AGS may also include

* Uncomfortable pressure fullness, squeezing, or pain in trie center of the chest

lasting several minutes ( usually more than a few minutes)
* Chest discomfort spreading to the shoulders, neck , one or both arms, or aw
* Chest discomfort spreading into the back or between the shoulder blades
* Chest discomfort with light headedness , dizziness, fainting, sweating, nausea
,
or vomiting
* Unexplained, sudden shortness of breath, which may occur with or without
chest discomfort

S3
 Consider the likelihood that the presenting condition is ACS or one of its potentially lethal
mimics. Other life- threatening conditions that may cause acute chest discomfort are aortic
dissection , acute pulmonary embolism (PE), acute penca/ dial elusion with tamponade ,
and tension pneumothorax.

Foundational Facts STEMI Chain of Survival

n The STEMI Chain of Survival (Figure 31) described by the AHA is similar to the Chain of
Survival for sudden cardiac arrest , it links actions to be taken by patients , family mem-
bers and heatthcare providers to maximize STEMI recovery These links are

* Rapid recognition and reaction So STEMI warning signs

* Rapid E MS dispatch and rapid EMS system transport and preamvai not itical son to the
receding hospital
Rap d assessment and diagnosis in the ED (or cath iab)
* '
* Rapid treatment

.
Figure 21, The STUMI rthain pf Sorvlvil

Starting With All dispatchers and EMS providers must receive Training in ACS symptom recognition
Dispatch along with the potential complications. Dispatchers, when authorized by medical con-
trol or protocol, should tell patients with no history of aspirin allergy or signs of active or
recent gasitromTestmal ( Gh deeding to chew aspirm D 60 to 125 mg) while waging for EMS
providers to arrive

EMS Assessment Care , and Hospital Preparation

}

Introduction EMS assessment , care , and hospital preparation are outlined m Step 2. EMS responders
may pert arm the following assessments and actions during the stabilization, Inage. and
transport of the patient to an appropriate facility :

* Monitor and support airway, breathing, and circulation ( ABCs) .

* Administer aspirin and consider oxygen H Q. saturation is less than 90% .
.
niTroglycenn and morphine if discomfort is unresponsive to nitrates,
* Obtain a 12 lead f GG ; interpret or transmit lor interpretation,
* Complete a fibrinolytic checklist if indicated .
* Provide preamvai notification lo the receiving facility rf ST elevation

Monitor and Monitoring and support of ABCs includes

Support ABCs
* Monitoring vital siqns and cardiac rhythm
* Being prepared to provide CPR
* Using a defibrillator rf needed

64
 The ACLS Cases; Acute Coronary Syndromes

Administer Oxygen Providers should be familiar with the actions, indications , cautions , and treatment of side
and Drugs effects ,

Oxygen
High inspired- oxygen tension will tend to maximize arterial oxygen saturation and. in turn,
arterial oxygen content This will heip support oxygen delivery* ( cardiac output * arterial
oxygen content) when cardiac output < s limited This short - term oxygen therapy does not
produce oxygen toxicity .
EMS providers should administer oxygen if the patient is dyspneic , is hypoxemic, has
obvious signs of heart failure , has an arterial oxygen saturation less than 90% . or the
oxygen saturation is unknown . Providers should titrate oxygen therapy to a nonmvasivefy
monitored oxyhemoglobin saturation 90% or greater . Because its usefulness has nor been
established In normoxic patients with suspected or confirmed AGSf providers may con-
sider withholding supplementary oxygen therapy in these patients .

Aspirin ( Acetylsalicyiic Acid)

A dose of t 60 to 325 mg of non-entenc -coated aspmn causes immediate and near - total
inhibition of thromboxane A production b inhibiting platelet cyclooxygenase i' COX - 1).
^
Platelets are one of the principal and earliest participants in thrombus formation. This
rapid inhibition also reduces coronary reocclusion and other recurrent events indepen -
dently and after fibrinolytic therapy.

If the patient has not taken aspirin and has no history of true aspinn allergy and no evi-
dence of recent Gl bleeding , give Ihe patient aspirin n 60 to 325 mg] to chew In the initial
.
hours of an AGS aspirin is absorbed better when chewed than when swallowed, particu -
larly if morphine has been given, Use rectal aspmn supposrlohes (300 mg) for patients
with nausea, vomiting, active peptic ulcer disease, or other disorders of the upper Gl tract .
Nitroglycerin (Glyceryl Trinitrate)
Nitroglycerin effectively reduces ischemic chest discomfort , and it has beneficial hemody -
namic effects. The physiologic effects Of nitrates Cause reduction in IV and right ventricu -
lar (RV) preload through peripheral artenaf and venous dilation.

Give the patient 1 sublingual nitroglycerin tablet (or spray “ dose 'l every 3 to 5 minutes
for ongoing symptoms if it is permitted by medical control and no contraindications exist.
Healthcare providers may repeat the dos© twice (total of 3 doses) Administer nitroglycerin
only if the patient remains hemodynamically stable . SBP is greater than 90 mm Hg or no
lower than 30 mm Hg below baseline (if known) and the heart rate is 50 to 100/min.

Nitroglycerin is a venodilater and needs to be used cautiously or not al all in patients with
inadequate ventricular preload. These situations include

* Inferior wall Ml and RV infarction. RV infarction may complicate an inferior wall Ml .

Patients with acute RV infarction are very dependent on RV filling pressures to main -
tain cardiac output and blood pressure it RV infarction cannot be ruled out. providers
,

must use caution in administering; nitrates to patients with inferior ST EMI If RV infarc -
tion is confirmed by right - sided precordkil leads or clinical findings by an experienced
provider, nitroglycerin and other vasod * :ators (morphine)- or volume - depleting drugs
(diuretics) are contraindicated as well

* Hypo tension, bradycardia , or tachycardia. Avoid use of nitroglycerin in patients

with hypotension ( SBP less than 90 mm Hg), marked bradycardia (less than 50/min),
or tachycardia.
* Recent phosphodiesterase inhibitor use . Avoid the use of nitroglycerin if rt is sus -
pected or known that the patient has taken sildenafil or vardenafH within the previous
24 hours or tadai'afil withm 48 hours These agents are generally used for erectile dys
function or in cases of pulmonary hypertension and in combination with nitrates may
cause severe hypotension refractory to vasopressor agents

65
 Opiates (eg , Morphine )

-
Give an opiate ( eg. morphine) for chest discomfort unresponsive to sublingual or spray
nitroglycerin if authorized by protocol or medical control. Morphine is indicated in STEMI
when chest discomfort is unresponsive to nitrates Use morphine with caution in NSTE -
ACS because of an association with increased mortality.

Morphine may be utilized in the management of ACS because it

Produces central nervous system analgesia, which reduces the adverse effects oi
neurohumoral activation , catecholamine release, and heightened myocardial oxygen
demand
Produces venodilation. which reduces LV preload and oxygen requirements
Decreases systemic vascular resistance thereby reducing LV after load
,

Helps redistribute blood volume In patients with acute pulmonary edema

Remember morphine is a venodilator tike nitroglycerin, use smaller doses and carefully
monitor physiologic response before administering additional doses in patients who may
.
be preload dependent If hypotension develops, administer fluids as a first line of therapy,

Critical Concepts Pain Relief With Nitroglycerin

/ Relief of pain with nitroglycerin is neither specific nor a useful diagnostic tool to deter-
mine hie etiology of symptoms in ED patients with chest pain or discomfort G ! etiolo -
gies as well as other causes of chest discomfort can respond to nitroglycerin adminis -
’

tration Therefore, the response to nitrate therapy is not; diagnostic oi ACS

Cautio/i Use of Nonsteroidal Anti - inflammatory Drugs

Use ot ncmrertJ' dii ' anti - inflammatory drugs fNSAIDsh is contraindicaled (except for
\ aspinnl and should be discontinued . Both non selective as well as COX -2 selective drugs
should not be admmislered during nose taxation tor STEM! because ot the increased
rrsk ot mortality, re infarction , hypertension , heart lailure , and myocardial rupture associ -
ated with their use.

66
 The ACLS Cases: Acute Coronary Syndromes

Obtain a providers should obtain .1 T 2

ead EGG. The AHA recommends out -of -hospita!
12 -Lead ECG i2 - iea<3 EGG diagnostic programs In urban and sohurban EMS systems.

EMS Action Recommendation

12 - Lead ECG If The AHA recommends routine use of 12 - lead out -of - hospital
available ECGs for patients with signs and symptoms of possible
ACS,
Prearrival hospital Preamval notification of the ED shortens the t >me to treat -
notification for STEM! ment (10 to 60 minutes has been achieved in clinical stud-
ies i and speeds reperfusion therapy with fibrinolytics or PCI
or both, which may reduce mortality and minimize myocar ^

dial injury.
Fibrinolytic check fist if -
If STEMI is identified on the 12 lead ECG , complete a fibri -
appropriate nolytic checklist if appropriate

m See the Student Website iwww.heart.org/ eccstudenti for a sample

hbnnofytic checklist

Immediate ED Assessment and Treatment

Introduction The high performance team should quickly evaluate the patient with potential ACS on the
patient s arrival in the ED Within the first 10 minuies. obtain a 12 - lead ECG ( if not already
'

performed before arr val) and assess the patient.

The 12 - lead ECG ( example in Figure 22 } is at the center of the decision

pathway in the management of ischemic chest discomfort and is the only
means of identifying ST EMI .

A targeted evaluation should be performed and focus on chest discomfort, signs and ,

symptoms of heart failure, cardiac history, risk factors for ACS» and historical features that
may preclude the use of fibrinolytics. For the patient with STEM! , the goals of rapertusion
are to give fibrinolytics within 30 minutes of arrival or perform PCI within 90 minutes ol
arrival

— —*
A

1-^ JU 4 - '
.-7' -* T
¥
I
f

_
_
— *> I

il- —
I

II
j -Ul
JVI
' p - v . .

VI
.L

n i£ri
i • "ri
"
.
A
i.

*T \4 -

,
i
" mrnntrri « vi
• •
| rye - *fH
Hl
"L J.

1 i rhr—^ i i
'

*i

ITTw A - w - * Jf J;

.
Figure 22 Antarkx STEM! on J 12 lead FGG

67
 P a r t

Figure 23 shows how to measure ST-segment deviation.

- J po»r1 ulus
Q 04 Mcand

MJ .
“
1 -

$T Bgrr«rrt
-
3
*Hsiwine | L

LTP sepmartf - T-
A ^n^rrr ijpwiatiDfl
= 5 .D mm
^baselinei

v- • •I

-
rpi ! fctl ! r=F =FE
1
— J pwrt
CXua 0 04
second

S#umw!
5T‘
bftsei
^
c\ jj t —

- 5T -wgniwir
dmMinon
= 45 mm
I
TP j

'r» «gm«r!l. IbiiseJ'nel

B

covered or
.
Figure 23 Hew to measure
concaves. B, Anlenof Ml
.
ST seomnni deviation. A Irrfenor Ml Tb« ST segment has r o low pom
- * (*
i is

The First 10 Minutes Assessment and stabilization of the patient in the first 10 minutes should include
lhe following:

* Check vital signs and evaluate oxygen saturation.

* Establish IV access.
* Take a brief focused history and perform a physical examination.
* Complete the fibrinolytic checklist and check for contraindications. rf indicated
- Obtain a blood sample to evaluate mitral cardiac marker levels electrolytes, and
coagulation.
* Obtain and review portable chest x -ray Hess than 30 minutes after the patient s arrival
m the ED). This should not delay fibnnolytic therapy for STEMI or activation of the PCI
team for STEMI
Note. The results of cardiac markers, chest x -ray and laboratory studies should not
(

delay reperfusion therapy unless clinically necessary, eg, suspected aortic dissection
or coagulopathy,

Patient General Unless allergies or contraindications exist, 4 agents may be considered in patients with
TYeatment ischemic - type chest discomfort

* Oxygen if hypoxemic |Q % less than 90%) or signs of head failure

* Aspirin
* Nrtroglycenn
* Opiate {eg, morphine if ongoing discomfort or no response to nitrates)
,

B< ^ ause these agents may hnve been given out of hospital; administer initial or supple
mentary doses as indicated ( See the discussion of these drugs in the previous section,
EMS Assessment , Care, and Hospital Preparation.)
68
 The >4 CIS Cases; Acufe Coronary Syndromes

Critical Concepts Oxygen, Aspirin, Nitrates, and Opiates

A A * Unless contraindicated, initial therapy with oxygen if needed
aspirin , nitrates and , . if
indicated morphine is recommended for all parents suspected of having ischemic
chest discomfort.
• The major contraindication to nitroglycerin and morphine is hypotension, including
hypotension from an RV infarction . The major contraindications to aspirin are true aspi -
rin allergy and active or recent Gl bleeding .

Classify Patients According to ST- Segment Deviation

Classify Into 3 Groups Heview tire initial 12- lead ECG (Step 4} and classify patients into 1 of the 3 following dim -
Based on ST-Segment .
cal groups (Steps 5 9 , and l1):
Deviation
General Group Description
STEMI ST elevation
NSTE - AGS -
ST depression or dynamic T wave inversion
Low - /intermediate-risk ACS Normal or nondiagnostic EGG

• STEMI is characterized by STsegmeni elevation in 2 or more contiguous leads or

new LBBB Threshold values for ST-segment elevation consistent with STEMI are
J-poinl elevation greater lhan 2 mm (0.2 mV l in leads V: and. V and 1 mm or more in
' +

ail other leads or by new or presumed new LBBB

' 2 5 mm in men younger than 40 years; t . 5 mm in all women .

* NSTE - ACS is characterized by ischemic ST segment depression 0.5 mm (0.05 mV) or

greater or dynamic T- wave inversion with pain or discomfort Nonpersistent or tran -
sient ST elevation 0.5 rum or greater for less than 20 minutes is also included in this
category ,
« Low - / tot rmediBtB-rmk ACS is characterized by normal or nondiagnostic changes in
*
the ST segment or T wave that are inconclusive and require further risk stratification
Ti is classification includes patients with normal ECGs and those with ST- segment
deviation in either direction of less than 0.5 mm ( 0.05 mV) or T-wave inversion <2 mm
or 0.2 mV. Serial cardiac studies and functional testing are appropriate. Note that
additional information { troponin) may place the patient into a higher risk classification
after initial classification
The EGG classification of ischemic syndromes is not meant to be exclusive A small per -
centaae of patients with normal ECGs may be found to have Mil, for example, If the initial
EGG is nondiagnostic and clinical circumstances indicate { eg . ongoing chest discomfort ),
repeat the EGG .

STEMI

Introduction Patients with STEMI usually have Complete occlusion of an epicardial coronary artery .

The mainstay of treatment for STEM ! t$ early reperfusion therapy achieved

with primary PCI or fibrinolytics.

69
 P a r t

Reperfusion therapy for STEMI is perhaps the most important advancement in treatment
-
of cardiovascular disease n recent years . Early fibrinolytic therapy or direct catheter-
based reperfusion has been established as a standard of care for patients with STEMI
who present within 12 hours of onset of symptoms with no contraindications. Reperfusion
therapy reduces mortal , and saves head muscle “ he shorter me time to reperfusion the
greater the benefit , A 47% reduction in mortality was noted when fibrinolytic therapy was
provided in ine first hour after onset of symptoms .

Critical Concepts Delay of Therapy

* Routine consultation with a cardiologist or another physician should not delay diagno -
sis and Treatment except in equivocal or uncertain cases. Consultation delays therapy
and is associated with increased hospital modality rates.
Potential delay dunng ihe in - hospital evaluation period may occur from door to data
(EGG), from data to decision, and from decision to drug (or PCI) I hese 4 major
-
points of in hospital therapy are commonly referred to as the " 4 D's .
H

• All providers must focus on minimizing decays at each of these points. Out - of - hospital
transport time constitutes only 5 % of delay to treatment time; ED evaluation consti -
tutes 25% to 33% of this delay.

Early Reperfusion Rapidly identify patients with STEM I and quickly screen them for indications and contmin -
Therapy dications to fibrinolytic therapy by using a fibrinolytic checklist if appropriate .

The first qualified physician who encounters a patient with STEMI should: interpret or con -
firm the 12 lead ECG determine the risk /benefit of reperfusion therap, and direct admin
,

istraiion of fibnnofytic therapy or activation of the PCI team. Early activation of PCI may
occur wrih established protocols . The following lime frames are recommended;

-
* For PC/, this goal for ED cioor-to balloon inflation time is 90 minutes tn patients
,

presenting to a non-PCI capable hospital, time from first medical contact to device
should be less than 120 minutes when primary PCI is considered
* If fibrinolysis is the intended reperfusion, an ED door - to- needle time (needle time is
the beginning of infusion of a fibnnoiytic agent ) of 30 minutes is the medical system
goal That is considered the longest time acceptable, Systems should strive to achieve
the shortest time possible.
* Patients who are ineligible for fibrinolytic therapy should be considered tor transfer to
a PC ! facility regardless of delay. The system should prepare for a door- to-departure
time of 30 minutes when a transfer decision is made.
Adjunctive treatments may also be indicated.

Use of PCI The most commonly used form of PCI is coronary intervention with stem placement .
Optimally performed pnmary PCI is the preferred reperfusion strategy over fibnnofytic
administration. Rescue PCI s used early after fibrinolytics in patients who may have per -
sistent occlusion of the infarct artery (failure to reperfuse with fibrinolytics! although this
'

term has been recently rep deed and included by the term pharmxoinvasfve $trafegy PCI
has been shown to be superior to Fibrinolysis in the combined end points of death stroke
, ,

and relnf auction in many studies tor patients presenling between 3 and 12 hours after
onset However these results have been achieved in experienced medical settings with
,

skilled providers (performing more than 75 PCls per year ) at a skilled PCI facility (perform-
ing more than 200 PCls for STEM! with cardiac surgery capabilities) .

70
 The ACLS Cases: Acute Coronary Syndromes

Considerations for the use of PCI include the following:

• PCI is the treatment of choice for the management of STEM! when it car be per-
formed effectively with a door-to-balloon time of ess than 90 minutes from first
medical contact by a sKrlled provider at a skilled PCI facility,
• Primary PCI may also be offered to patients presenting to non-PCI-capable centers
if PCI can be initiated promptly within 120 minutes from first medical contact. The
TRANSFER AMI (Trial of Routine Angioplasty and Stenting Afrer Fibrinolysis to
Enhance Reperfus<on in Acute Myocardial Infarction) trial supports the transfer of
high-risk patients who receive fibrinolysis in a non- PCI center within 12 hours of
symptom onset to a PCI center within 6 hours of fibrinolytic administration to receive
routine early coronary angiography and PCI if indicated.
• For patients admitted to a hospital without PCI capabilities, there may be some
benefit associated with transfer for PCI versus administration of on - site fibrinolytics
in terms of reinfarction, stroke, and a trend to lower mortality when PCI can be
performed within 120 minutes of first medical contact.
PCI is also preferred in patients with contraindications to fibrinolytics and is indicated
in patients with cardiogenic shock or heart failure complicating ML

Use of Fibrinolytic -
A fibrinolytic agent or “clot -busterp is administered to patients with J-point ST segment
Therapy elevation greater than 2 mm (0.2 mV) in leads V , and Va. and 1 mm or more in all other
. ,
leads or by new or presumed new LBBB (eg leads lllr aVF; leads V;], V : leads I and aVL)
without contraindications . Fibrin - specific agents are effective in achieving normal flow
in about 50% of patients given these drugs. Examples of fibrin-specific drugs are rtPA ,
reteplase. and tenecteplase. Streptokinase was the first fibrinolytic used widely, but it is
not fibrin specific .
Considerations for the use of fibrinolytic therapy are as follows:
• In the absence of contraindications and in the presence of a favorable risk -benefit
ratio, fibrinolytic therapy is one option for reperfusion in patients with STEMI and
onsef of symptoms within 12 nours of presentation with qualifying ECG findings and
rf PCI * s not available within 90 minutes of first medical contact,
* In the absence of contra ndications, it is also reasonable to give fibrinolytics to
patients with oosef of symptoms within the prior 12 hours and ECG findings
consistent with true posterior ML Experienced providers will recognize this as a con -
dition where ST-segment depression in the early precordial leads is equivalent to
ST-segment elevation in others . When these changes are associated with other ECG
findings, it is suggestive of a “ STEMI" on the posterior wall of the heart .
presenting more than
* Fibrinolytics are generally not recommended for patients
12 hours after onset of symptoms . But they may be considered if ischemic chest
discomfort continues with persistent ST- segment elevation.
• Do not give fibrinolytics to patients who present more than 24 hours after theMlonset
is
of symptoms or patients with ST- segment depression unless a true posterior
suspected,

Adjunctive Other drugs are useful when indicated in addition to oxygen, sublingual or spray nitroglyc -
Treatments erin. aspirin, morphine , and fibrinolytic therapy. These include

• Unfractionated or low -molecular - weight heparin

* Bivalirudin
P2 Yi: inhibitors
* IV nitroglycerin
• 3 - Blockers
* Glycoprotein llb/ IHa inhibitors

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 P a r t

IV nitroglycerin and heparin are commonly used early in the management of patients with
STEMI, These agents are briefly discussed below Use of bivalirudln, P2Y , j inhibitors ,
.
D-blockers and glycoprotein Ilb/ 1Ha inhibitors will not be reviewed Use of these agents
requires additional risk stratification skills and a detailed knowledge of the spectrum of
ACS and in some instances, continuing knowledge of the results of clinical trials

Heparin (Unfractionated or Low - Molecular -Weight )

Heparin is routinely given as an adjunct for PCI and fibrinolytic therapy with fibrin - specific
agents (rtPA. reteplase . tenecteplase) , It is also indicated m other specific high - risk situa -
tions. such as LV mural thrombus, atrial fibrillation, and prophylaxis for venous thrombo -
embolism in patients with prolonged bed rest and heart failure complicating Ml If you use
these drugs, you must be familiar with dosing schedules for specific clinical strategies.

The inappropriate dosing and monitoring of heparin therapy has caused

excess intracerebral bleeding and major hemorrhage in STEM I patients.
Providers using heparin need to know the indications. dosing; and use in
the specific ACS categories .

The dosing. use. and duration have been derived from use in clinical trials.
Specific patients may require dose modification, See the ECC Handbook
for weigh( based dosing guidelines , intervals of administration, and adjust -
ment of low - molecular -weight heparin in renal function. See the ACC / AHA
guidelines for detailed discussion m specific categories «

IV Nitroglycerin
Routine use of IV nitroglycerin is not indicated and has not been shown to significantly
reduce mortality in STEMI IV nitroglycerin is indicated and used widely in ischemic
syndromes It is preferred over lopicai or long - acting forms because r! can be titrated in
a patient with potentially unstable hemodynamics and clinical condition. Indications for
initiation Of IV nrtrogtycenn in STEMI are
• Recurrent or continuing chest discomfort unresponsive to sublingual or spray nitroglycerin
• Pulmonary edema complicating STEM!
• Hypertension complicating STEMI
Treatment goals using fV nitroglycerin are as follows.

Treatment Goal Management

Relief of ischemic chest discomfort * Titrate to effect
* Keep SRP greater than 90 mm Hg
* Limit drop in 58P to 30 mm Hg below
baseline in hypertensive patients
Improvement in pulmonary edema and * Titrate to effect
hypertension
* Limit drop in SBP to 10 % of baseline in
normotensive patients
* Limit drop in SRP to 30 mm Hg below
baseline in hypertensive patients

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