Feedback Cardiology

Acute Coronary Syndrome with ST elevation

Pathophysiology

  • Proximal occlusion of a major coronary artery

ECG

  • Diagnosis usually on the basis of ECG
  • The ST segments rise in the leads corresponding to the part of the heart that is damaged
    • The V leads – anterior infarction
    • VL and V5/6 – lateral infraction
    • III and VF – inferior infarction
  • STEMI is dx when there is
    • >1mm of ST elevation (STE) in at least 2 contiguous limb leads
      • E.g. I + VL; III + VF)
    • Or >2mm of STE in at least 2 contiguous precordial leads
    • Or new LBBB
  • Prompt treatment by PCI or thrombolysis can prevent myocardial damage, so Q waves don’t develop
    • Q wave is considered pathological if it is >1 small square wide (>0.04s) and/or >2 small square tall (>2mm)
  • Sequence of ECG in a pt with STEMI
    • ECG changes in STEMI STE
    • T wave inversion in affected leads
    • After a few days, ST segment returns to baseline and Q waves develop

TREATMENT FOR ACS

Acute management for pts with symptoms of ACS

Pre-hospital

  • Aspirin – [300mg po]
  • Analgesia + antiemetic – IV (avoid i.m. injections due to risk of bleeding)
    • Morphine [5-10mg]
    • Metoclopramide – [10mg]
  • Sublingual GTN – [300mcg]

Hospital management

  • ECG – to distinguish STEMI from NSTEMI/UA
  • Oxygen – if saturation <94%

Immediate STEMI management

  • Cardio referral
  • PCI – for pts presenting within 12 hrs of chest pain
    • Involves either balloon angioplasty or stent implantation
    • Give gp IIb/IIIa inhibitor alongside PCI
      • Abciximab
  • Thombolysis if PCI unavailable (don’t give to pts who don’t have STE)
    • Streptokinase
  • Start heparin

Immediate NSTEMI management

  • Cardio referral
  • PCI – if GRACE score is high
  • Do not give thrombolytic therapy

Tx once ACS pts are stable

  • Anti-platelet therapy
    • Clopidogrel/ticagrelor and aspirin
  • Beta blocker
    • Atenolol – [5mg IV]
  • ACE-Inhibitors
  • Statins
    • Aim for total cholesterol <4mmol/L and HDL>1mmol/L

Full drug regime – after discharge

  • Aspirin [100mg]
  • Metoprolol [50mg b.i.d]
  • Ramipril [2.5-10mg]
  • Simvastatin [50mg b.i.d]
  • Clopidogrel [300mg loading + 75mg maintenance]
  • Epleronone [25mg]

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