Acute Coronary Syndromes

1
Acute Coronary Syndromes

• EMS Professions
• Temple College

2
The History of Paramedics Begins with Cardiac
Care

• The original Paramedic idea was based upon the
  need for rapid response to, identification of and
  emergency care for victims of
  
• Sudden Cardiac Death (SCD)
• Acute Myocardial Infarction (AMI)

3
Ischemic Coronary Syndromes

• Acute Coronary Syndromes
• Angina Pectoris
• Unstable Angina
• Acute Myocardial Injury
• Acute Myocardial Infarction
• Presentation with suspected ischemia
• Non-diagnostic ECG
• ST segment depression
• ST segment elevation/New BBB

4
Ischemic Coronary Syndromes

• Angina Pectoris
• Acute pain, usually in the chest, resulting from
  an increased demand for oxygen and a decreased
  ability to provide it
  
• Usually due to a partially occluded coronary
  artery or vasospasm

5
Ischemic Coronary Syndromes

• Angina Pectoris
• Typical Presentation
• Squeezing, Crushing, Heavy, Tight
• Fist to chest Levines sign
• Pain/Discomfort may radiate to shoulders, arms,
  neck, back, jaw or epigastrium
  
• Usually lasts 3-5 min and rarely exceeds 15 min
• Not changed by swallowing, coughing, deep
  breathing or positional changes

6
Ischemic Coronary Syndromes

• Angina Pectoris
• Typical Presentation
• Anxiety
• Diaphoresis or clammy skin
• Nausea, vomiting
• Shortness of breath
• Weakness
• Palpitations
• Syncope

7
Ischemic Coronary Syndromes

• Angina Pectoris
• Usually Provoked by
• Exercise
• Eating
• Emotion/Stress
• Usually Relieved by
• Rest Removal of provoking factor
• Nitroglycerin

8
Ischemic Coronary Syndromes

• Stable Angina Pectoris
• Reasonably Predictable frequency, onset,
  duration
  
• Relief predictable with rest, nitroglycerin

9
Ischemic Coronary Syndromes

• Stable Angina Pectoris
• Treatment Goals
• Reduce myocardial oxygen demand
• Improve myocardial oxygen supply

10
Ischemic Coronary Syndromes

• Stable Angina Pectoris
• Treatment
• Physical/Psychological rest
• Position of comfort, sitting or supine
• Oxygen
• ECG Monitor
• Assess the underlying rhythm
• Nitroglycerin, 0.4 mg SL q 5 min as long as BP
  90 mm Hg
  
• Continue until pain relieved or contraindicated

11
Ischemic Coronary Syndromes

• Stable Angina Pectoris
• Transport Considerations
• Many persons stay home and treat themselves
• Treat first-time angina, unstable angina or
  angina requiring more than 3 NTG (15 min) as
  AMI
  
• When in doubt, treat as AMI

12
Ischemic Coronary Syndromes

• Stable Angina Pectoris
• Variant Angina (Prinzmetals Angina)
• Occurs at rest
• Episodes at regular times of day
• Results from coronary vasospasms
• Treated long term with calcium channel blockers
• May result in abnormal 12 lead ECG changes that
  resolve with minimal treatment

13
Ischemic Coronary Syndromes

• Unstable Angina
• Prolonged chest pain/ischemic symptoms or an
  atypical presentation of angina without ECG or
  laboratory evidence of AMI (Injury)
  
• Usually associated with significant or
  progressing occlusion of a coronary artery or
  severe vasospasm
  
• Considered Pre-infarction Angina

14
Ischemic Coronary Syndromes

• Unstable Angina
• May have Typical or Atypical Signs Symptoms
• Atypical Presentation
• Increased frequency or duration of episodes
• Onset with less exertion than normal
• Increased severity of symptoms
• Requires greater number of NTG tablets to relieve
  symptoms

15
Ischemic Coronary Syndromes

• Unstable Angina
• Treatment same as Angina PLUS
• IV, NS (no dextrose), TKO
• Some exceptions to restricting fluid
• 12 Lead ECG
• Assess for RVI
• Morphine sulfate, 2 - 4 mg q 5-15 min slow IV
  titrated to pain relief and BP 90
  
• Aspirin, 160-325 mg PO
• Chewed swallowed if possible
• Determine if hypersensitive to ASA

16
Ischemic Coronary Syndromes

• Unstable Angina
• Treatment
• Metoprolol, 5 mg slow IV q 5 min to 15 mg total,
  prn for ? HR/BP in absence of contraindications
  
• In longer or interfacility transports, consider
• Nitroglycerin IV infusion, 10-20 mcg/min
• Heparin
• GP IIB/IIIA inhibitors
• Thrombolytics Checklist (just in case)
• Transport, destination?

17
Ischemic Coronary Syndromes

• Acute Myocardial Injury
• Presentation of Unstable Angina or Acute Ischemia
  with potential for myocardium salvage (penumbra)
  
• Diagnostic evidence of Injury (ECG or elevated
  Enzymes)
  
• Does not necessarily imply necrosis of the
  myocardium
  
• Presentation, Signs and Symptoms are the same as
  Acute MI

18
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Necrosis of myocardial tissue caused by a lack of
  oxygenation and blood flow resulting from an
  occluded coronary artery
  
• Often also used to describe acute injury when
  extent of necrosis is unknown but imminent
  
• Diagnostic evidence of injury is present
  (elevated enzymes and possibly ECG)

19
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Precipitating Factors
• Coronary thrombosis (most common)
• Coronary vasospasm
• Microemboli
• Severe Hypotension/Shock
• Acute Hypoxia
• Acute Volume Overload

20
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Location, size of infarct and severity depends on
  site of vessel occlusion
  
• majority involve left ventricle
• LCA
• anterior, septal, lateral
• RCA
• inferior, right ventricle

21
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Often defined further as
• subendocardial involves only subendocardial
  muscle
  
• transmural full thickness of ventricular wall
  involved

22
Evolution of AMI
23
Evolution of AMI
24
Evolution of AMI
25
Coronary Artery Without Evidence of Plaque
Source University of Utah WebPath
26
Coronary Artery with Significant Plaque Formation
In addition to reduced Lumen size, there is also
a calcified portion (right side of photo)
Source University of Utah WebPath
27
Coronary Artery with Significant Plaque Formation
Source University of Utah WebPath
28
Rupture of Atheromatous Plaque Results in
Thrombus Formation

• Rupture of Vulnerable plaques soft lipid core
  is the initiating event in most acute ischemic
  coronary events
  
• Occlusion is dependent on clot formation and and
  accompanying fibrinolysis
  
• A thrombotic occlusion that is relatively
  persistent (i.e., 2 to 4 hours or longer) may
  result in acute myocardial infarction

29
Rupture of Atheromatous Plaque Results in
Thrombus Formation

• Repeated thrombus formations may further
  decrease the lumen size
  
• Intermittent non-occlusive thrombus formation
  results in Unstable Angina
  
• Incomplete occlusion may also result in MI
  possibly due to coronary artery spasm

30
Coronary Artery With Plaque and Thrombus
Formation
A - Coronary Artery cross-section
B - Lumen C - Fissured Plaque w/o Cap D -
Acute thrombus
Source Emergency Cardiovascular Care Library
(CD-ROM), American Heart Association, Dallas 1997
31
Plaque and Thrombus Formation Resulting in
Occlusion
Source University of Utah WebPath
32
Coronary Artery Thrombus
The external anterior view of the heart shows a
dark clot formation in this artery
Source University of Utah WebPath
33
Evolution of Infarction/Necrosis
34
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Presentation
• Similar to Angina but
• Last longer
• Not easily relieved with rest or NTG
• Sx/Sx may be more severe (feeling of impending
  doom)
  
• Pain often radiates to arms, neck, jaw, back,
  epigastrium
  
• Some present atypically with complaints of only
  weakness or shortness of breath
  
• Dysrhythmias
• Sudden Cardiac Death

35
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Presentation
• 10-20 have silent MI (no chest pain)
• common in elderly, older women, diabetics
• If adding chest pain to the patients list of
  Sx/Sx completes a clear picture of AMI, then the
  patient is having an AMI!!
  
• Vital Signs and monitoring ECG leads DO NOT
  provide DIAGNOSTIC evidence of AMI!!
  
• Clinical diagnosis in absence of 12 Lead ECG or
  Enzyme changes

36
Therapies
37
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Treatment Goals
• Decrease myocardial oxygen demand
• Remove physical/psychological stressors
• Relieve pain
• Reduce workload of the heart (BP, HR)
• Inhibit further clot formation
• Rapid identification/diagnosis
• Transport for reperfusion therapy

38
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Treatment same as Angina PLUS
• IV, NS, large bore
• TKO with some exceptions
• No dextrose containing solutions
• Fluid boluses appropriate in some cases
• 2nd line if time permits
• Minimize number of attempts
• 12 Lead ECG
• Diagnostic evidence of AMI present
• Assess for RVI

39
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Treatment
• Morphine sulfate, 2 - 4 mg q 5-15 min slow IV
• Maintain BP 90 mm Hg
• Titrated to Pain relief
• Reduce PVR and workload on the heart
• Aspirin, 160-325 mg PO
• Chewed swallowed if possible
• Determine if hypersensitive to ASA
• MONA greets all patients

40
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Treatment
• Metoprolol, 5 mg slow IV q 5 min to 15 mg total,
  prn for ? HR/BP in absence of contraindications
  
• In longer or interfacility transports, consider
• Nitroglycerin IV infusion
• Heparin
• Thrombolytics Checklist
• Exclusions for thrombolysis

41
Ischemic Coronary Syndromes

• Acute Myocardial Infarction (AMI)
• Treatment
• Transport for reperfusion therapy Destination?
• Thrombolysis vs Coronary Artery Catheterization
• For patients with associated pulmonary edema,
  hypotension or cardiogenic shock, consider
  transport to facility with capability of
  angiography revascularization

42
Considerations for Fibrinolytics
43
Contraindications for Fibrinolytics

• Lack of diagnostic 12 Lead ECG changes
• Chest pain 12 hours
• Not oriented, can not cooperate
• History of stroke or TIA
• Known bleeding disorder
• Active internal bleeding in past 2-4 weeks

• Surgery or trauma in past 3 weeks
• Terminal illness
• Jaundice, hepatitis, kidney failure
• Use of anticoagulants
• Systolic BP
• Diastolic BP

44
Ischemic Coronary Syndromes

• Ischemic and injured tissue have reduced blood
  flow but may be salvaged. The area of the
  Penumbra may be viable for several hours after
  onset of occlusion.
• Source Emergency Cardiovascular Care Library
  (CD-ROM), American Heart Association, Dallas, 1997

45
Ischemic Coronary Syndromes

• Sudden Cardiac Death (SCD or SCA)
• Sudden, unexpected biologic death presumably
  resulting from cardiovascular disease
  
• Most common rhythm of SCA is Ventricular
  Fibrillation
  
• May be primary or secondary VF
• Chain of Survival is the greatest determinant of
  outcome
  
• Treatment based on ECG rhythm arrest events

46
Time is Muscle!!!
47
References and Resources

• Advanced Cardiac Life Support, Edited by R O
  Cummins, MD, American Heart Association, Dallas,
  1997
  
• Emergency Cardiovascular Care Library (CD-ROM),
  American Heart Association and ProEducation
  International, Dallas, 1997
  
• Eisenberg, M S, Life in the Balance Emergency
  Medicine and the Quest to Reverse Sudden Death,
  Oxford University Press, New York, 1997
  
• A Definition of Advanced Types of
  Atherosclerotic Lesions and a Histological
  Classification of Atherosclerosis, A Report
  From the Committee on Vascular Lesions of the
  Council on Arteriosclerosis, American Heart
  Association, 1995
• Coronary Artery Calcification Pathophysiology,
  Epidemiology, Imaging Methods, and Clinical
  Implications, A Statement for Health
  Professionals From the American Heart
  Association, 1995
• Cardiovascular Disease Statistics, American Heart
  Association, Dallas, 1997
  
• Diagnosis and Therapy of Acute Myocardial
  Infarction Todays Look at Tomorrows Therapies
  and Outcomes, DuPont Pharma, 1997
  
• University of Utah WebPath, http//medstat.med.uta
  h.edu/webpath/