ACS: unstable angina, NSTEMI and STEMI

Question 1

Define:
Stable angina
Unstable angina
NSTEMI
STEMI

Answer 1

-Stable angina: stable atherosclerotic plaque formation in the artery

-Unstable angina: atherosclerotic plaque ruptures and thrombus forms. No tissue damage

-NSTEMI: atherosclerotic plaque ruptures and thrombus forms. Partial tissue damage.

-STEMI: atherosclerotic plaque ruptures and thrombus forms. Greater extent of tissue damage.

Question 2

What are the clinical features of ACS?

Answer 2

Central, crushing chest pain that radiates to arm, jaw or neck that lasts > 15 minutes

Chest pain is:
-Associated with N+V, sweating, breathlessness or a combination
-Associated with HDUS
-Of a new-onset or is the result of an abrupt deterioration fo stable angina with pain occuring frequently with little or no exertion and often lasts >15mins.

Question 3

What must you be wary of in diabetics and ACS?

Answer 3

Diabetics may not experience typical chest pain during an ACS. This is often referred to as silent MI. They are at higher risk of having a silent MI as cardiac dysfunction occurs which involves damage to pain receptors, afferent neurones or higher areas of the brain.

Question 4

What investigations would you do?

Answer 4

1. Bloods - Troponin I and T
2. ECG- new LBBB or ST elevation diagnoses STEMI.

Question 5

What are the ECG findings in NSTEMI?

Answer 5

ST segment depression
Deep T-wave inversion

Question 6

What are the ECG findings in STEMI? State the progression

Answer 6

Few minutes - T-wave becomes tall, pointed and upright and there is ST segment elevation

Few hours - the T-waves invert, the R-wave voltage is decreased and the Q-waves develop

After a few days - ST segment may return to normal

After a few weeks or months - the T-wave may return to upright but Q-wave remains.

Question 7

What is the difference between NSTEMI vs STEMI?

Answer 7

NSTEMI - partial blockage of coronary artery. Do not usually develop Q-waves. Non-ST segment elevation.

STEMI - full blockage of the coronary artery. Usually progresses to Q-waves. ST-elevation.

Question 8

What is Troponin and is it elevated?

Answer 8

Troponin I and T are enzymes released when there is myocardial damage.

Usually elevated 3-6 hours after the NTSEMI or STEMI

Question 9

How do you differentiate between unstable angina and NSTEMI + STEMI?

Answer 9

Cardiac troponin I and T are NOT elevated in unstable angina but is elevated in NSTEMI + STEMI.

Question 10

What is the acute management of NSTEMI and STEMI?

Answer 10

Use guidelines

Question 11

Name the 6 drugs used for secondary prevention management

Answer 11

-Aspirin - 75mg daily
-Another anti-platelet - clopidogrel or ticagrelor for up to 12 months
-Atorvastatin - 80mg OD
-ACE-Is
-Atenolol (or another BB)
-Aldosterone antagonist - if they have clinical heart failure

Question 12

What are the ischaemic territories for inferior MI? Which artery is it indicative of?

Answer 12

II, II and aVF
RCA/Left circumflex artery

Question 13

What are the ischaemic territories lateral MI?
Which artery is it indicative of?

Answer 13

I, aVL, V5 and V6
Left circumflex

Question 14

What are the ischaemic territories for anteroseptal MI?
Which artery is it indicative of?

Answer 14

V1-V4
LAD

Question 15

What are the ischaemic territories for a posterior MI?
Which artery is it indicative of?

Answer 15

Tall R-waves in V1-V2
Usually left circumflex but also right coronary