Acute Coronary Syndromes

Question 1

Greatest specific cause of CVD mortality

Answer 1

CAD

Question 2

Stable ischemic heart disease definition

Answer 2

Exertional chest pain (or equivalent) that is chronic
May be asymptomatic
Typically seen in the outpatient clinic setting

Question 3

Pathophysiology of stable ischemic heart disease

Answer 3

Obstructive (collaterals) or non-obstructive coronary artery plaque
Intact fibrous cap
Minimal platelet activation, inflammation
Other conditions: aortic stenosis, HOCM

Question 4

Angina pectoris

Answer 4

Pain or discomfort in the chest caused by
insufficient blood supply to the heart muscle
Typically brought on by exertion or emotional stress
Typically lasts 1-15minutes
Relieved by rest and nitroglycerin

Question 5

Populations more likely to have non-classical presentation of angina pectoris

Answer 5

women, elderly, people with diabetes

Question 6

Diagnostic value of exercise stress ECG depends on the __________________ of having coronary artery disease

Answer 6

pre test probability

Question 7

Stress nuclear scintigraphy

Answer 7

Nuclear imaging method, areas of blood flow are “hot”, areas of infarct or ischemic tissue will remain “cold”. Pre- and post-stress results may indicate areas that will benefit from myocardial revascularization

Question 8

Fractional flow reserve

Answer 8

Measure pressure upstream and downstream of blockage- can gauge functional (rather than anatomic) severity of a plaque

Question 9

Treatments that relieve symptoms of stable ischemic heart disease

Answer 9

Nitrates, calcium channel blockers, beta blockers, re-vascualrization (stent/ angioplasty or CABG)

Question 10

Treatments that prevent adverse outcomes (MI, stroke, death) of stable ischemic heart disease

Answer 10

Lifestyle measures
Aspirin
Statins
ACE-Is
P2Y12 receptor blockers

Question 11

In stable ischemic heart disease, CABG is superior to medical therapy for two specific types of disease:

Answer 11

• L main disease

- severe three vessel disease with reduced LV function

Question 12

Unstable ischemic heart disease is also called…

Answer 12

acute coronary syndrome

Question 13

Unstable ischemic heart disease definition

Answer 13

New or rapidly progressive symptoms

Typically seen in the emergency room setting

Question 14

Unstable ischemic heart disease pathophysiology

Answer 14

obstructive coronary artery plaque; plaque rupture or erosion; platelet activation, inflammation, thrombus

Question 15

Why do plaques rupture?

Answer 15

• mechanical factors- shear stress
• inflammation
• exogenous factors ex smoking
• endogenous factors ex catecholamines

Question 16

Why do coronary arteries thrombose?

Answer 16

• activation of intrinsic clotting (tissue factor)
• platelet activation
• endothelial dysfunction

Question 17

Platelet activation triggers

Answer 17

catecholamines
cigarette smoking
collagen
tissue factor
vWF

Question 18

Platelet activation feed back

Answer 18

ADP
Serotonin
TXA2

Question 19

Acute coronary syndrome includes:

Answer 19

• unstable angina
• NSTMEI
• STEMI

Question 20

Characteristics of unstable angina

Answer 20

• mild or no changes to ECG

- no biochemical evidence of myonecrosis

Question 21

Characteristics of NSTEMI

Answer 21

• T inversion on ECG

- some biochemical evidence of myonecrosis

Question 22

Characteristics of STEMI

Answer 22

• ST elevation on ECG

- much biochemical evidence of myonecrosis

Question 23

Steps in emergency assessment of acute coronary syndrome

Answer 23

Characterize discomfort onset, character, severity
Identify risk factors
Physical Examination – signs of instability
Cardiac Biomarkers (Troponin, CK-MB)
ECG (ST depression or ST elevation)
Rule out other causes of chest pain

Question 24

TIMI risk score

Answer 24

Used to risk stratify patients presenting with unstable angina/ NSTEMI

• score of 0-2= lower risk, do stress test ECG to gain further info
• score of 3-7= higher risk, do invasive revascularization (cath)

Question 25

Treatments that relieve symptoms of unstable angina/ NSTEMI

Answer 25

nitroglycerine, morphine

Question 26

Treatment that prevents adverse events in unstable angina/ NSTEMI

Answer 26

``` Anti-platelet therapy Anti-thrombin therapy Statins Beta-blockers ACE-Inhibitors Revascularization Lifestyle measures ```

Question 27

Antiplatelet therapy agents

Answer 27

aspirin (irreversibly blocks COX1, decreased production of TXA2, less platelet activation) P2Y12 receptor blockers (irreversibly inhibit receptor on platelet membrane to prevent formation of GpIIbIIIa complex) GpIIbIIIa inhibitors (directly prevent fibrionogen cross linking)

Question 28

Anti- thrombin agents

Answer 28

Heparin, direct thrombin inhibitors, Factor Xa inhibitors

Question 29

Should fibrinolytic therapy be used for unstable angina or NSTEMI?

Answer 29

NO- no benefit since vessel is not fully occluded, only harm from bleeding risk

Question 30

In what cases should stents/ CABG be used for unstable angina or NSTEMI?

Answer 30

- High risk features (L main or 3 vessel disease with reduced LV function)

Question 31

Management of STEMI

Answer 31

``` PROMPT Reperfusion Aspirin P2Y12 Receptor blocker Cardiac Care Unit Care Statin Beta-blocker ACE-Inhibitor Cardiac Rehab ```

Question 32

List some problems with thrombolytic therapy

Answer 32

Failure to open infarct artery ~40% Intracranial hemorrhage 1-2% Contraindications up to 40% Lytic outcomes consistently inferior to timely PCI

Question 33

If fibrinolytic therapy is to be used in a patient with STEMI, what is the time frame for administration?

Answer 33

30 minutes, with rescue PCI if fibrinolytic doesn't work

Question 34

What is the ideal/ goal time frame for reperfusion by stent/ angioplasty in STEMI?

Answer 34

90 minutes

Question 35

List some complications following MI

Answer 35

Ventricular arrhythmias- poor prognosis if more than 48 hours after MI Post-MI pericarditis Cardiogenic shock- prognosis is very poor Congestive heart failure

Question 36

What region of the heart is most vulnerable to infarct expansion?

Answer 36

antero-apical region- thinnest area of myocardium, greatest curvature, greatest deforming forces, site of thrombus due to stasis, site of rupture