Is Acute Coronary Syndrome a heart attack? 

Yes but heart attack is often used non-specifically to refer to a myocardial infarction and to sudden cardiac death.

ACS has three main arms:

 ST elevation myocardial infarction (STEMI) 31%,

Non-ST elevation myocardial infarction (NSTEMI) 32%,

Unstable Angina (UA) 26%, and

 Two secondary arms:

•             cardiac diagnosis 8%,
•             noncardiac final diagnosis 4%.

What is STEMI?

            Tissue death of the heart muscle due to blockage of the coronary artery which supply the blood to the heart, it manifests by:

• Severe chest pain with cold sweat, shortness of breath, nausea……
•  ECG changes like ST elevation – Q wave – new  left bundle branch block,
• Cardiac biomarkers like Troponin I – T ( rise occur in 2-3 hours of injury to the heart muscle and peaks in 1-2 days)  CK MB which is less specific than troponin.
• Changes in the motion of the heart wall on echocardiography (regional hypokinesia).
• Coronary angiogram shows blockage by thrombus either complete or incomplete so PCI doing its action to open this blocked artery and restore the blood flow to the heart muscle.

What is NSTEMI?

It is myocardial infarction manifest by severe chest pain and high troponin but the ECG shows either ST depression or T inversion but no ST elevation and here the blockage of coronary artery is more likely incomplete.