Acute Coronary Syndromes

1. Acute Coronary Syndromes Terry White, RN, EMP-T

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 = Levine’s 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 (Prinzmetal’s 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” plaque’s 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 patient’s 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. Lack of diagnostic 12 Lead ECG changes Chest pain < 20 min or > 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 < 180 mm Hg Diastolic BP < 110 mm Hg Contraindications for Fibrinolytics

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: Today’s Look at Tomorrow’s Therapies and Outcomes”, DuPont Pharma, 1997 • University of Utah WebPath, http://medstat.med.utah.edu/webpath/