Cardiology - Ischaemic Heart Disease

Question 1

Fractional Flow Reserve

• how is it done?
• Cut-offs?

Answer 1

Adenosine is used to induce maximal hyperaemia
= gold standard for VESSEL SPECIFIC ISCHAEMIA

FFR <0.8 = ISCHAEMIA

Question 2

Fractional Flow Reserve: benefit when used during PCI

Answer 2

In multivessel disease during PCI it reduced MI and death

Question 3

In the pathogenesis of atherosclerosis:

Which apolipoprotein combines with LDL, where and what do they do?

Answer 3

LDL combines with Apolipoprotein B in the INTIMA and binds to extracellular matrix

Question 4

In the pathogenesis of atherosclerosis:

What are foam cells?

Answer 4

Foam cells develop when MONOCYTES take up lipoprotein particles by endocytosis

Question 5

In the pathogenesis of atherosclerosis:

How is cholesterol transferred from cell to HDL?

Answer 5

via the ABC (ATP Binding Cassette) transporters

ABC-A1 gene transfers to nascent HDL (mutated in Tangier’s with VERY LOW HDL)

ABC-G1 gene transfers to mature HDL

Question 6

In the pathogenesis of atherosclerosis:

Role of ABC-A1 gene?

Answer 6

Transfers cholesterol from cell to nascent HDL

mutated in Tangier’s with VERY LOW HDL

Question 7

In the pathogenesis of atherosclerosis:

Role of ABC-G1 gene?

Answer 7

Transfers cholesterol from cell to mature HDL

Question 8

Which ABC gene transfers cholesterol from cell to NASCENT HDL?

Answer 8

ABC-A1

Question 9

Which ABC gene transfers cholesterol from cell to MATURE HDL?

Answer 9

ABC-G1

Question 10

What is mutated in Tangier’s?

Answer 10

ABC-A1 gene resulting in VERY LOW HDL

Question 11

What does HDL do with the cholesterol it picks up?

Answer 11

HDL delivers cholesterol to hepatocytes via Scavenger Receptor B1

Question 12

What produces PDGF?

And what does PDGF do in the pathogenesis of atherosclerosis?

Answer 12

PDGF = Platelet Derived Growth Factor

It is produced by activated platelets, macrophages and endothelial cells.

It stimulates smooth muscle cells in tunica media to migrate to intima

Question 13

In the pathogenesis of atherosclerosis:

What does TGF-beta do?

Answer 13

Stimulates smooth muscle cells to make collagen

Question 14

In the pathogenesis of atherosclerosis:

What makes plaques prone to rupture?

Answer 14

• thin fibrous caps
• large lipid cores
• high macrophage content
• outward remodelling
• spotty calcification rather than dense

Question 15

Which coronary arteries are typically effected in stable angina?

Answer 15

Stable angina is usually angina secondary to atherosclerosis of EPICARDIAL arteries

Question 16

What is microvascular angina?

Answer 16

Angina with no flow-limiting obstruction in the epicardial arteries

Question 17

Is microvascular angina more common in males or females?

Answer 17

Females

Question 18

How do you diagnose microvascular angina?

Answer 18

Coronary reactivity tests with vasoactive agents: ie:

• intracoronary adenosine
• intracoronary acetylcholine
• intracoronary nitroglycerides

Question 19

How do you manage microvascular angina?

Answer 19

Nitrates
Betablockers
CCBs
Statins

Question 20

Who do you see ABNORMAL CARDIAC NOCICEPTION in, and how do you treat?

Answer 20

Abnormal cardiac nociception is a type of angina with no flow-limiting obstruction in epicardial arteries (LIKE microvascular but NOT)
Seen in FEMALES
Trial treatment with IMIPRAMINE

Question 21

Link between CRP and Stable Angina?

Answer 21

If the CRP level in stable angina is elevated it is an INDEPENDENT RISK FACTOR

Can help reclassify it as ‘intermediate risk’

Question 22

ECG features that increase risk of adverse events in STABLE ANGINA?

Answer 22

LVH

Question 23

When do you use Exercise Stress Test for chest pain?

Answer 23

If intermediate pre-test probability 10 - 90%

Question 24

How good is Exercise Stress Testing in coronary artery disease?

Answer 24

Sensitivity 80%, Specificity 70%

If POSITIVE and MALE >50yrs with a typical history of pain IN THE TEST then likelihood of CAD is 98%

Question 25

What is Exercise Stress Test MOST SENSITIVE for?

Answer 25

Triple vessel disease

Question 26

What coronary artery might result in a FALSE NEGATIVE on your Exercise Stress Test?

Answer 26

Left Circumflex

Question 27

Ideal goal when doing an Exercise Stress Test?

Answer 27

To exercise 6 - 12 minutes to achieve 85% of age-predicted max-heart rate (220-age)

Question 28

What is the DUKE TREADMILL SCORE and what is it based on?

Answer 28

Provides 5yr mortality Based on: - development of symptoms - degree of ST depression - exercise duration

Question 29

In the first minute of stopping an Exercise Stress Test, what increases your mortality?

Answer 29

If your heart rate recovery is <12bpm in the first minute then INCREASED mortality

Question 30

What meets criteria for a positive Exercise Stress Test?

Answer 30

``` >3mm ST depression >2mm ST elevation SBP >230mmHg Fall of SBP >20mmHg HR DECREASES >20% of starting rate Arrythmia ```

Question 31

Contraindications to an Exercise Stress Test?

Answer 31

- Aortic Stenosis - LBBB - MI <7 days ago - Rest angina <48 hours ago - Uncontrolled BP

Question 32

Problem with WOMEN doing an Exercise Stress Test?

Answer 32

Women have a high rate of FALSE POSITIVES BUT if the woman is LOW RISK then the Exercise Stress Test is similar to a nuclear med myocardial perfusion scan

Question 33

Risk of doing an Exercise Stress Test?

Answer 33

1 in 10,000 mortality | 1 in 10,000 non-fatal events

Question 34

Is an stress echo or exercise stress test more sensitive?

Answer 34

A stress echo is more sensitive because it assesses if stress causes regions of AKINESIS or DYSKINESIS

Question 35

In nuclear stress tests what is used to stress the heart? | How do they work?

Answer 35

DOBUTAMINE: increases myocardial oxygen demand ADENOSINE or DIPYRIDAMOLE: Temporarily increases flow in nondiseases segments to cause flow disparity

Question 36

Which medication used in nuclear stress tests increases myocardial oxygen demand?

Answer 36

Dobutamine

Question 37

Which medication used in nuclear stress tests temporarily increases flow in nondiseases segments to cause flow disparity

Answer 37

Adenosine or Dipyridamole

Question 38

What classifies a MARKEDLY POSITIVE nuclear exercise test?

Answer 38

Lung uptake of thallium Ischaemia in >2 vascular territories EF <35%

Question 39

What classifies as MARKEDLY POSITIVE exercise echo?

Answer 39

EF <35% at rest Fall in EF with stress Ischaemia in >2 vascular territories

Question 40

The severity of coronary artery narrowing WHERE is associated with a higher risk in stable angina?

Answer 40

Left main | LAD proximal to origin of first septal artery

Question 41

In treating STABLE ANGINA: | Should you use a statin?

Answer 41

YES! - stabilises plaque - Reduces risk of MI and death (25 - 30%) - reduces LDL (25 - 30%) - reduces TGAs (5 - 30%) - INCREASES HDL (5-9%)

Question 42

How do nitrates work?

Answer 42

Relax vascular smooth muscle by releasing NITRIC OXIDE that binds to GUANYLYL CYCLASE in smooth muscle and INCREASES cGMP Results in: - systemic venodilation with reduced LV EDV and pressure - increased collateral flow - dilation of epicardial vessels

Question 43

What do nitrates result in?

Answer 43

Increases Exercise TOLERANCE | but NOT mortality benefit

Question 44

Effect of nitrates on bleeding?

Answer 44

Antithrombotic effect Because NO-dependent activation of platelet guanylyl-cyclase, impaired intraplatelet calcium flux and platelet activation

Question 45

Which five medication classes work as anti-anginals? (excluding perhexiline)

Answer 45

``` Nitrates Betablockers CCBs (nondihydropyridine) Ranolazine Nicorandil ```

Question 46

Which calcium channel blockers can you use for their anti-anginal effect?

Answer 46

Non-dihydropyridine CCBs: verapamil and diltiazem

Question 47

How does ranolazine work as an antianginal?

Answer 47

Selective inhibitor of late inward sodium channel in myocardium --> prevents calcium overload via Na/Ca exchange

Question 48

When is ranolazine contraindicated?

Answer 48

- hepatic impairment - QTc prolongation - use with CYP3A4 inhibitors

Question 49

How does nicorandil work as an antianginal?

Answer 49

Opens ATP-sensitive K channels in myocyte to cause reduction of free intracellular calcium

Question 50

When do you revascularise in stable angina?

Answer 50

If symptoms persist despite medical treatment

Question 51

At which SYNTAX SCORE is coronary artery disease considered severe?

Answer 51

>22

Question 52

Benefit of PCI in treatment of stable angina?

Answer 52

More effective for RELIEF BUT No better than medical treatment for mortality or MI

Question 53

How many BMS have restenosis in 6 months?

Answer 53

20%

Question 54

How many DES have restenosis in 6 months?

Answer 54

<10%

Question 55

What increases your risk of restenosis after revascularisation?

Answer 55

- diabetes - small arteries or incomplete dilation - longer stent

Question 56

When do we use CABG in preference to stenting in coronary artery disease?

Answer 56

- left main disease - three vessel disease - LV dysfunction - diabetes IF MULTI-VESSEL

Question 57

Benefit and Risks of CABG compared to stenting?

Answer 57

Benefit: - mortality <1% - occlusion much lower, with 10-20% in 1st year and <2% per year afterwards Bad: - recurrence of angina in 25% by 3 years - higher stroke risk than PCI