Coronary Heart Disease 2 - Acute Coronary Syndromes

Question 1

Do veins or arteries have less smooth muscle?

Answer 1

Veins

Question 2

What does ACS stand for?

Answer 2

Acute Coronary Syndromes (also known as a heart attack)

Question 3

What are the 3 types of ACS?

Answer 3

• Unstable Angina
• STEMI
• NSTEMI

Question 4

Describe the progression of ACS (8 steps).

Answer 4

1. destabilization of plaque (fibrous cap) due to blood flow (shearing)
2. lining is disrupted, collagen exposed triggering platelets
3. platelets adhere to exposed collagen and change their shape
4. after activated, the platelets give off thromboxane A2 and ADP
5. ADP binds to P2Y12 receptor which activates GpIIb/IIIa receptor on the platelet
6. neighbouring platelets can crosslink fibrinogen as part of the clotting cascade
7. more platelets aggregate due to TxA2, serotonin, thrombin
8. fibrinogen converted to fibrin using thrombin

Question 5

What are the 3 receptors involved in the progression of ACS?

Answer 5

P2Y12
GPIIb/IIIa
Fibrinogen

Question 6

Explain the difference between white clots and red clots.

Answer 6

White:
-more platelets than fibrin
-incomplete artery occlusion
-more common in NSTEMI
Red:
-more fibrin than platelets
-usually complete artery occlusion
-more common in STEMI

Question 7

What is the main difference between stable angina and ACS (symptoms)?

Answer 7

ACS symptoms do not go away if you rest! Stable angina symptoms do go away if you rest.

Question 8

What does an EKG do?

Answer 8

Measures the electric activity of the heart. Has different waves (PQRST)

Question 9

Explain the purpose of a Troponin T test.

Answer 9

The release of troponin T is a marker of cardiac cell (myocyte) death. High results of troponin T indicate that there has been damage to the heart

Question 10

What does PCI stand for? Explain it.

Answer 10

Percutaneous Coronary Intervention: Also known as an angioplasty or stenting. A catheter and tube is inserted into the coronary arteries. A balloon is inflated which pushes the plaque to the wall of the blood vessel. A metal stent can be put in to hold the artery open or a drug-releasing stent can be put in. This is done to correct blockage that has taken place in the coronary arteries.

Question 11

What does CABG stand for? Explain it.

Answer 11

Coronary Artery Bypass Graph:
A great blood vessel is harvested (great saphenous vein or LIMA (left internal mammary artery) and cut into pieces. One end is sewn to the aorta and the other end is sewn downstream of the blockage. The number of blockages determined how many bypasses need to be done.

Question 12

What is the difference between STEMI and NSTEMI?

Answer 12

STEMI - shows ST elevation on an EKG

NSTEMI - shows ST depression and/or T inversion as well as elevated troponin T levels

Question 13

What is an unstable angina?

Answer 13

Shows ST depression and/or T inversion as well as non-elevated levels of troponin T

Question 14

What test is done to differentiate between what type of ACS something is?

Answer 14

EKG

Question 15

What is a myocardial infarction ?

Answer 15

Also known as a heart attack. It is when blood flow to a part of the heart is stopping which causes damage to the heart muscle.

Question 16

What are symptoms of an ACS?

Answer 16

-If pain happens when the person is at rest
-If nitroglycerin doesn’t help
Other symptoms that are consistent with stable angina are:
-shortness of breath
-nausea
-fatigue
-pain (chest or referred)
-swelling

Question 17

Describe the flow chart of the EKG tests and diagnoses when determining what type of ACS something may be.

Answer 17

• If the EKG shows ST elevation you know it is a STEMI.
• If it shows ST depression and/or T inversion then you have to do a Troponin T to further diagnose.
• If the Troponin T levels are elevated you have an NSTEMI.
• If the Troponin T levels are not elevated you have an UNSTABLE ANGINA.

Question 18

What types of medication would help prevent a heart attack?

Answer 18

• Asprin - prevents thromboxane A2 which causes platelets to be sticky and makes clots bigger
• Statin’s (rosuvastatin, atorvastatin) - it will lower your LDL cholesterol levels
• Warfarin - thins the blood
• Beta blocker - B1 receptors are found in the heart. We use specific beta blocker stop block B1 receptors in the heart which decreases heart rate. (If you decrease heart rate you decreases oxygen demand which in turn decreases oxygen supply)
• epitifibatide - GPIIb/IIIa inhibitor
• alteplase or tenectiplase (these are fibrinolytic and break fibrin clots)
• clopidogrel - blocks P2Y12 receptor therefore the GPIIb/IIIa is not activated
• heparin and low molecular weight heparins - disrupts clotting cascade and LMWH