IHD 1

Question 1

What is the definition of ischaemia

Answer 1

-When oxygen and nutrient supply is higher than demand
-Cellular metabolism requirements not met

Question 2

How do you classify ischaemia

Answer 2

-Chronic stable ischaemia/angina
-Acute Coronary Syndrome

Question 3

Define chronic stable ischaemia/angina

Answer 3

-Classified as an intermediate condition of slow changes

Question 4

Define acute coronary syndrome

Answer 4

-A sudden change in supply to the myocardium that can lead to cell death (necrosis)

Question 5

What are examples of acute coronary syndrome?

Answer 5

-STEMI
-NSTEMI
-Unstable angina

Question 6

What are the aetiology of ACS?

Answer 6

1) Atherosclerotic
2) Non-atherosclerotic
-Emboli
-Trauma
-Aneurisms/fistulas
-Congenital
-Spasm (cocaine, prinzmetal)

Question 7

What is the timeline of atherosclerosis

Answer 7

-Endothelial damage and dysfunction
-Lipid accumulation and macrophages enter to try and remove lipid - forms foam cells
-Fibrotic plaque forms
-Plaque rupture and thrombosis
-Inflammation

Question 8

Chronic stable angina vs ACS

Answer 8

-Restriction of blood flow vs Block of blood flow
1) Increased demand cannot be supplied due to limited blood flow through a smaller area in coronary artery (atheroma)
2) Blockage in the coronary artery causes myocardial necrosis

Question 9

MI risk factors

Answer 9

-Gender
-Stress
-Diabetes
-Hypertension
-Obesity

Question 10

Symptoms of IHD

Answer 10

-Angina
-Dyspnoea
-Nausea
-Syncope
-Palpitations
-Diaphoresis

Question 11

Chronic stable angina vs ACS (in practice)

Answer 11

-Chronic stable angina usually only causes symptoms on exertion
-Symptoms of angina, diaphoresis, nausea over 20/30 mins indicate ACS
-Chronic stable angina can be relieved by rest and GTN spray, ACS causes prolonged pain

Question 12

What is the diagnostic triad to evaluate for IHD?

Answer 12

-Clinical Hx
-ECG
-Cardiac biomarkers

Question 13

When taking clinical history, what would you be looking for to evaluate for IHD

Answer 13

-How long was the pain?
-Is the patient sweaty, nauseous, syncopal?
-Is pain relieved by GTN spray?

Question 14

What would you look out for on ECG to evaluate for IHD?

Answer 14

-ST, T wave changes
-Do they resolve on rest/GTN?

Question 15

What are cardiac biomarkers?

Answer 15

-Enzymes that indicate cell death
E.g.
-Myoglobin
-CK
-CK-MB
-Troponin I

Question 16

What other conditions could be responsible for same symptoms as MI?

Answer 16

-Pericarditis/myocarditis
-Pulmonary embolism (young women can get it when on the pill)
-Pancreatitis

Question 17

What are the management objectives of chronic stable ischaemia?

Answer 17

-Prevent a future acute coronary event
-Relieve pain
-Improve quality of life
-Treat any complications

Question 18

What is the management of chronic stable IHD?

Answer 18

Modify risk factors
-diet
-exercise

Pharmacological
-Anti-platelet aggregation
-Nitrates
-Beta blockers

Revascularisation
-Elective coronary intervention
=> Coronary Artery Vein/Bypass Graft (CAVG/CABG)

Question 19

What are the management objectives of ACS?

Answer 19

-Prevent death
-Pain relief - opioids
-Limit damage to the myocardium - aspirin
-Treat complications - GTN

Question 20

What is a risk of giving GTN spray after ACS

Answer 20

-GTN lowers blood pressure
-Patient could go into cardiogenic shock

Question 21

What is the pharmacological management (objectives and drugs) of ACS?

Answer 21

Objective:
-Treat pain
-Increase blood flow
-Decrease myocardial demand

Drugs:
-Morphine
-Nitrates
-Anti-platelets
-Beta blockers
-Renin Angiotensin Aldosterone inhibitors
-Glucose control

Question 22

What is the interventional management of ACS?

Answer 22

Revascularisation:
-PCI, CABG

Support:
-Intra aortic balloon

Identify and treat complications:
-Temporary pacing
-Surgery for ischaemic VSD
-Valve incompetence

Question 23

If you had no access to PCI what could you use as revascularisation therapy?

Answer 23

-Streptokinase clotbuster
=>However, it has low efficacy and can cause other bleeds

Question 24

What are some complications of ACS?

Answer 24

-Conduction disturbances
-Arrhythmia
-Rupture of the septum
-Aneurysm
-Valve incompetence due to papillary muscle rupture
-Cardiogenic shock
-Death

Question 25

What are some examples of arrhythmias and conduction disturbances which could be caused by ACS?

Answer 25

Arrhythmias: -Ventricular Tachycardia/Fibrillation -Atrial flutter/Fibrillation -Sinus bradycardia -Idioventricular rhythm Conduction disturbances: -Atrio-ventricular blocks -His-purkinge/Bundle branch blocks

Question 26

What features of coronary artery anatomy determine their susceptibility to ischaemia?

Answer 26

-Work load -Areas of turbulence (corners) -Location in heart

Question 27

Which coronary arteries arteries are most vulnerable to ischaemia?

Answer 27

-Vessels in the left ventricular, sub endocardium Due to: -mass -workload -distal nature