ABSTRACT
Unstable Angina ■ Clinical syndrome resulting from rupture of an unstable
plaque or from a critically stenotic stable plaque ■ It is defined by any of the following:
▲ Rest angina-angina occurring at rest and usually lasting >20 minutes within a week before presentation
▲ New-onset angina-angina of at least Canadian Cardiovascular Society class III severity within 2 months before initial presentation
▲ Worsening angina-previously diagnosed angina that is more frequent, longer in duration or lower in threshold, and has worsened by at least one class within 2 months after initial presentation to at least Canadian Cardiovascular Society class III severity
Myocardial Infarction ■ Diagnosed by the presence of at least two of the following
three criteria: ▲ Prolonged chest pain (>30 minutes) or anginal equivalent
■ Subdivisions ▲ NSTEMI-characterized by an increase in troponin I or T in
the clinical setting of acute coronary syndrome and/or STsegment depression >1 mm in two or more contiguous leads
▲ STEMI-characterized by ST-segment elevation >1 mm in two or more contiguous leads or left bundle branch block (LBBB) not known to be old
■ Unstable angina cannot be distinguished from NSTEMI at presentation.
