Conditions & Treatments

Acute Coronary Syndromes - Diagnosis

ACS consists of 3 conditions which can cause angina and can be further differentiated based on electrocardiogram (ECG) and blood tests (cardiac markers imply damage of the heart muscle). The clinical presentation and prognosis of ACS depend on the degree of narrowing of the artery caused by the thrombus after the plaque rupture.

Unstable angina – worsening of pervious narrowing after plaque rupture but not completely occluded. There is worsening of angina (more frequent angina, angina with lesser exertion, angina at rest or recent onset angina). As there is no heart muscle damage resulting in cell death, cardiac markers would not be elevated.
Non-ST elevation myocardial infarction (NSTEMI or partial heart attack) – partial or transient complete occlusion of the artery after plaque rupture. There is evidence of muscle damage on blood tests resulting in elevation of cardiac markers but there is no characteristic ST segment elevation on ECG.
ST elevation myocardial infarction (STEMI or full heart attack) – Complete and persistent occlusion of artery after plaque rupture. There is evidence of muscle damage with elevation of cardiac markers in blood test with characteristic ST segment elevation on ECG.