Diagnostic studies acute coronary syndromes

• ECG: ST ↓/↑, TWI, new LBBB, hyperacute Tw; Qw/PRWP may suggest prior MI & ∴ CAD ✓ ECG w/in 10 min of presentation, with any ∆ in sx & at 6–12 h; compare w/ baseline

• STEMI dx challenging w/ old LBBB or ventricular pacing:

  • Sgarbossa criteria: ≥1 mm STE concordant w/ QRS (Se 73%, Sp 92%), STD ≥1 mm V1–V3 (Se 25%, Sp 96%), STE ≥5 mm discordant w/ QRS (Se 31%, Sp 92%)
  • Barcelona criteria:

• Localization of MI

• Cardiac biomarkers:

  • ✓ Tn (pref. over CK-MB) at presentation & 3–6 h if stnd assay or 1 h later if high-sens assay;
  • repeat if clinical or ECG ∆s.
  • Universal definition of MI:
    • at > 99th %ile w/ rise and/or fall in appropriate clinical setting
      • (eg, sx, ECG ∆s, WMA on TTE, thrombus on coronary angiography).

• If low prob, stress test or CT angio to r/o CAD;

  • new wall motion abnl on TTE suggests ACS

• Coronary angio gold standard for epicardial CAD