1 Case 6 Acute Coronary Syndromes © 2001 American Heart Association.

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Case 6

Acute CoronarySyndromes© 2001 American Heart Association

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Learning ObjectivesLearning Objectives

At the end of Case 6 be able to Define acute coronary syndromes Use the Ischemic Chest Pain Algorithm Consider the Why? (actions), When? (indications),

How? (dose), and Watch Out! (precautions) of medications for ischemic chest pain patients

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Learning Objectives (cont’d)Learning Objectives (cont’d)

At the end of Case 6 be able to Recognize significant ST-segment changes Know how to measure ST-segment elevation

and depression Know basic principles of anatomic localization of

infarct, injury, and ischemia Know how to use the ECG to risk-stratify patients

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Case 1Case 1

A 55-year-old man presents with a chief complaint of severe (10 of 10) substernal chest pain. He has pain radiating down his left arm and up into his jaw, nausea, and a profound sense of impending doom. He is covered with small beads of sweat.

Vital signs: TEMP = 37.2°C; HR = 110 bpm; BP = 150/100 mm Hg; RESP = 12

Describe your immediate assessment.Describe your immediate general treatment.

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Ischemic Chest Pain AlgorithmIschemic Chest Pain Algorithm

Immediate assessment (<10 minutes)• Measure vital signs (automatic/standard BP cuff)• Measure oxygen saturation• Obtain IV access• Obtain 12-lead ECG (physician reviews)• Perform brief, targeted history and physical exam;

focus on eligibility for fibrinolytic therapy• Obtain initial serum cardiac marker levels• Evaluate initial electrolyte and coagulation studies• Request, review portable chest x-ray (<30 minutes)

Chest painsuggestive of ischemia

Immediate general treatment• Oxygen at 4 L/min• Aspirin 160 to 325 mg• Nitroglycerin SL or spray• Morphine IV (if pain not relieved with

nitroglycerin)

Memory aid: “MONA” greetsall patients (Morphine, Oxygen, Nitroglycerin, Aspirin)

EMS personnel canperform immediateassessment and treat-ment (“MONA”),including initial 12-lead

ECG and review forfibrinolytic therapyindications andcontraindications.

Assess initial 12-lead ECG

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Items of Immediate Assessment (<10 min) Items of Immediate Assessment (<10 min)

Check vital signs with automatic or standard BP cuff Determine oxygen saturation Obtain IV access Obtain 12-lead ECG Obtain a brief, targeted history and perform a physical

examination; use checklist (yes-no); focus on eligibility for fibrinolytic therapy

Obtain blood sample for initial cardiac marker levels Initiate electrolyte and coagulation studies

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Immediate General TreatmentImmediate General Treatment

Oxygen at 4 L/min Aspirin 160 to 325 mg Nitroglycerin SL or spray Morphine IV (if pain not relieved

with nitroglycerin)

Review the Why? (actions), When? (indications), How? (dose), and Watch Out! (precautions) of these medications to consider in patients with ischemic chest pain.

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Medications Used in ACLSMedications Used in ACLS

Why? (Actions) When? (Indications) How? (Dose) Watch Out! (Precautions)

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Oxygen Used in Acute Coronary Syndromes

Oxygen Used in Acute Coronary Syndromes

Why? Increases supply of oxygen to ischemic tissueWhen? Always when AMI is suspectedHow? Start with nasal cannula at 4 L/min Remember one word: oxygen-IV-monitorWatch Out! Rarely COPD patients with hypoxic

ventilatory drive will hypoventilate

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Nitroglycerin: ActionsNitroglycerin: Actions

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

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Nitroglycerin: IndicationsNitroglycerin: Indications

Class I: First 24 to 48 hours in patients with ST-segment elevation or depression including• LV failure (acute pulmonary edema or CHF)• Elevated BP (especially with signs of LV failure)• Large anterior infarction• Persistent ischemia

Suspected ischemic chest pain Unstable angina (change in angina pattern) Acute pulmonary edema (if BP >90 mm Hg systolic)

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Nitroglycerin: DoseNitroglycerin: Dose

Sublingual: 0.3 to 0.4 mg; repeat every 5 minutes Spray inhaler: 2 metered doses at 5-minute intervals IV infusion: 12.5 to 25 g bolus, 10 to 20 g/min

infusion, titrated

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Nitroglycerin: PrecautionsNitroglycerin: Precautions

Use extreme caution if systolic BP <90 mm Hg Use extreme caution in RV infarction

– 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

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Morphine Sulfate: Actions, IndicationsMorphine Sulfate: Actions, Indications

Why? (Actions)• To reduce pain of ischemia• To reduce anxiety• To reduce extension of ischemia by reducing

oxygen demands When? (Indications)

• Continuing pain• Evidence of vascular congestion (acute pulmonary edema)• Systolic blood pressure >90 mm Hg• No hypovolemia

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Morphine Sulfate: Dose, Precautions

Morphine Sulfate: Dose, Precautions

How? (Dose)

• 2 to 4 mg titrated to effect

• Goal: Eliminate pain Watch out for (Precautions)

• Drop in blood pressure, especially in patients with

– Volume depletion

– Increased systemic resistance

– RV infarction

• Depression of ventilation

• Nausea and vomiting (common)

• Bradycardia

• Itching and bronchospasm (uncommon)

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Aspirin: ActionsAspirin: Actions

Why? (Actions)

• Blocks formation of thromboxane A2 (thromboxane A2 causes platelets to aggregate and arteries to constrict)

These actions will reduce• Overall mortality from AMI• Nonfatal reinfarction• Nonfatal stroke

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Aspirin: Indications, Dose, Precautions

Aspirin: Indications, Dose, Precautions

When? (Indications) As soon as possible!• Standard therapy for all patients with new pain suggestive

of AMI• Give within minutes of arrival

How? (Dose) 160- to 325-mg tablet taken as soon as possible Watch Out! (Precautions)

• Relatively contraindicated in patients with active peptic ulcer disease or asthma

• Contraindicated in patients with known aspirin hypersensitivity• Bleeding disorders• Severe hepatic disease

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Assess Initial 12-Lead ECG Findings

Assess Initial 12-Lead ECG Findings

Classify patients with acute ischemic chest pain into

1 of the 3 groups above within 10 minutes of arrival.

• ST elevation or new or presumably new LBBB:

strongly suspicious for injury

• ST-elevation AMI

• ST depression or dynamicT-wave inversion:

strongly suspicious for ischemia

• High-risk unstable angina/non–ST-elevation AMI

• Nondiagnostic ECG:absence of changes in ST segment or T waves

• Intermediate/low-riskunstable angina

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Recognition of AMI Recognition of AMI

Know what to look for—• ST elevation >1 mm• 3 contiguous leads

Know where to look• Refer to 2000 ECC

HandbookPR baseline

ST-segment deviation= 4.5 mm

J point plus0.04 second

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How to MeasureST-Segment Deviation

How to MeasureST-Segment Deviation

PR baseline

J point plus0.04 second

ST-segment deviation

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12-Lead ECG Variations in AMI and Angina

12-Lead ECG Variations in AMI and Angina

Baseline

Ischemia—tall or inverted T wave (infarct),ST segment may be depressed (angina)

Injury—elevated ST segment, T wave may invert

Infarction (Acute)—abnormal Q wave,ST segment may be elevated and T wavemay be inverted

Infarction (Age Unknown)—abnormal Q wave,ST segment and T wave returned to normal

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AMI LocalizationAMI Localization

aVF inferiorIII inferior V3 anterior V6 lateral

aVL lateralII inferior V2 septal V5 lateral

aVRI lateral V1 septal V4 anterior

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Anterior Septal AMIAnterior Septal AMI

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ß-Blockersß-Blockers

Mechanism of action• Blocks catecholamines from binding to

ß-adrenergic receptors• Reduces HR, BP, myocardial contractility • Decreases AV nodal conduction • Decreases incidence of primary VF

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ß-Blockersß-Blockers

Severe CHF/PE SBP <100 mm Hg Acute asthma

(bronchospasm) 2nd- or 3rd-degree

AV block

Mild/moderate CHF HR <60 bpm History of asthma IDDM Severe peripheral

vascular disease

AbsoluteContraindications Cautions

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HeparinHeparin

Mechanism of action• Indirect thrombin inhibitor (with AT III)

Indications• PTCA or CABG• With fibrin-specific lytics • High risk for systemic emboli

– Conditions with high risk for systemic emboli, such as large anterior MI, atrial fibrillation, or LV thrombus

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ACE InhibitorsACE Inhibitors

Mechanism of action• Reduces BP by inhibiting angiotensin-converting

enzyme (ACE)• Alters post-AMI LV remodeling by inhibiting

tissue ACE• Lowers peripheral vascular resistance

by vasodilatation• Reduces mortality and CHF from AMI

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Fibrinolytic TherapyFibrinolytic Therapy

Breaks up the fibrin network that binds clots together Indications: ST elevation >1 mm in 2 or more contiguous

leads or new LBBB or new BBB that obscures ST• Time of symptom onset must be <12 hours • Caution: fibrinolytics can cause death from brain

hemorrhage Agents differ in their mechanism of action, ease of preparation

and administration; cost; need for heparin 5 agents currently available: alteplase (tPA, Activase),

anistreplase (Eminase), reteplase (Retavase), streptokinase (Streptase), tenecteplase (TNKase)

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Antiplatelet AgentsAntiplatelet Agents

Blocks glycoprotein IIb/IIIa receptors on platelets

Blocked receptors cannot attach to fibrinogen

Fibrinogen cannot aggregate platelets to platelets

Indications: ACS with NO ST-segment elevation:• Non–Q-wave MI• Unstable angina managed medically• UA undergoing PCI

Examples: abciximab (ReoPro), eptifibitide (Integrilin), tirofiban (Aggrastat)

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Percutaneous Transluminal Coronary Angioplasty

Percutaneous Transluminal Coronary Angioplasty

Direct treatment Mechanical reperfusion

of infarct-related coronary artery

Best outcome achieved for patients with AMI plus cardiogenic shock

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What Does This 12-Lead ECG Show?What Does This 12-Lead ECG Show?

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1 Case 6 Acute Coronary Syndromes © 2001 American Heart Association.

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Transcript of 1 Case 6 Acute Coronary Syndromes © 2001 American Heart Association.