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ST Elevation Myocardial Infarction (STEMI) /Acute Myocardial Infarction (AMI)


ST Elevation Myocardial Infarction (STEMI) /Acute Myocardial Infarction (AMI)
ST Elevation Myocardial Infarction (STEMI) /Acute Myocardial Infarction (AMI)
ST Elevation Myocardial Infarction (STEMI) /Acute Myocardial Infarction (AMI)

STEMI/AMI is a medical emergency caused by the complete or partial occlusion of a coronary artery and requires prompt hospitalization and intensive care intervention management.

Sign and Symptoms

Severe chest pain with the following characteristics, site: retrosternal or epigastric, quality: crushing, constricting or burning pain or discomfort, radiation: to the neck and/or down the inner part of the left arm, duration: at least 20 minutes and often not responding to sublingual nitrates, occurrence: at rest. May be associated with: pulmonary oedema sweating, hypotension or hypertension, arrhythmias

Diagnostic Criteria

Initial diagnosis:

Management including both diagnosis and treatment of STEMI/AMI starts at the point of first medical contact (FMC), defined as the point at which the patient is either initially assessed by a paramedic or physician or other medical personnel in the pre-hospital setting, or the patient arrives at the hospital emergency department.

Simple recognition triage: Two out of three points most likely point to STEMI/AMI diagnosis

• Symptoms - typical/atypical chest pain
• ECG – ST elevation in in two contiguous leads≥0.1mV
• Raised cardiac biomakers– Total Creatine Kinase (Total-CK), Creatine Kinase MB (CK-MB) and Standard/High Sensitive Troponin I or T



  • Pharmacological

    Control cardiac pain
    • Glyceryl trinitrate sub-lingual/ spray 0.5mg (make sure patient hasn’t taken phosphodiesterase-5 inhibitor). For persistent pain and if oral therapy is insufficient
    • Glyceryl Trinitrate IV, 1–2 µg/kg/min titrated with chest pain over 8–24 hours.
    • Morphine, IV, 1–2 mg/minute dilute 10 mg up to 10 mL with sodium chloride solution 0.9%. Total maximum dose: 10 mg, repeat after 4 hours if necessary.
    Anti-platelets therapy
    • Aspirin 300mg stat (O) then followed by 75mg/100mg daily
    • Clopidogrel 300mg/600mg stat then followed by 75mg daily next day

    Statin high dose

    • Simvastatin 80mg stat then 40mg daily
    • Atorvastatin 80mg stat then 40mg daily
    • Rosiivastatin 10mg-40mg daily

    • Heparin UFH 70–100U/Kg body weight IV a day
    • Enoxaparin 1mg/kg body weight sc bid, Reduce dose in renal failure patient to 0.5mg/kg

    Beta blocker (ß –blockers)

    In case of LV dysfunction
    • Carvedilol initial dose 6.25mg twice daily preferred, titrate dose upward to maximum dose 25mg twice daily In the settings of normal systolic function
    • Atenolol 12.5mg or 25mg or 50mg once a day,
    • Metoprolol 25m/ or 50mg once a day

    Angiotensin-Converting Enzyme Inhibitors (ACEIs)
    • Captopril 6.25mg or 12.5mg (PO) 8 hourly
    • Enalapril 10mg twice a day
    • Perindopril 4mg/8mg (PO) daily

    Definitive management of STEMI – Reperfusion therapy (Myocardial reperfusion)

    Myocardial reperfusion with rapid recanalization of infarct related artery is the key to success in the management of ST Elevation Myocardial Infarction (STEMI).

    Timely reperfusion is crucial for minimization of infarct size and thereby for preservation of left ventricular function and reduction in mortality in STEMI patients

    The two main reperfusion strategies for STEMI patients are;
    • Thrombolytic/Fibrinolytic therapy) and
    • Primary percutaneous coronary intervention (PPCI)
    Thrombolytic agents
    • Streptokinase IV, 1.5 million units diluted in 100 mL sodium chloride 0.9%, infused over 30–60 min
    • Alteplase (TPA) 15mg as bolus, 0.75mg/kg over 30min, then 0.5mg/kg over 60min
    • Tenecteplase 40mg IV bolus (70–79kg body weight) 30 –35mg < 70kg body

    Absolute contraindication for thrombolytic

    • Previous allergy to streptokinase or used within the last year for streptokinase only
    • Stroke CVA within the last 3 months
    • History of recent major trauma
    • Bleeding within the last month
    • Aneurysms
    • Brain or spinal surgery or head injury within the preceding month
    • Active bleeding or known bleeding disorder

    Relative contraindication for Thrombolytic

    • Refractory hypertension
    • TIA in the preceding 6 months,
    • Subclavian central venous catheter
    • Warfarin therapy
    • Pregnancy
    • Traumatic resuscitation
    • Recent retinal laser treatment

    Referral is urgent for all suspected or diagnosed cases to high level care equipped with cardiac catheterization laboratory.
  • Non-Pharmacological

    Supportive therapy

    • Consider cardio-pulmonary resuscitation if necessary before transfer (cardiac arrest– cardiopulmonary resuscitation).
    • Oxygen 40% via facemask, if saturation < 92% or if in distress
    • See section 20.4.1 above on supportive therapy for NSTEMI


Updated on,

5 Novemba 2020 09:49:18


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