7. Ischaemic Heart Disease

Question 1

What increases the oxygen demand of the myocardium?

Answer 1

Rate
Contractability
Tension

Question 2

What affects the oxygen supply to the myocardium?

Answer 2

Oxygenated blood

Coronary artery flow

Question 3

What part of the heart is supplied by the left anterior descending artery?

Answer 3

Anterior wall of LV
Apex
Anterior 2/3 of the septum

Question 4

What part of the heart is supplied by the right coronary artery?

Answer 4

Posterior wall

Question 5

Name the forms of ischaemic heart disease

Answer 5

Angina
MI
Chronic ischaemic heart disease

Question 6

What is stable angina?

Answer 6

Chest pain brought on by exercise and relieved by rest

75% occlusion of one of main coronary arteries

Question 7

How is stable angina assessed?

Answer 7

Angiography

Question 8

What conditions worsen stable angina?

Answer 8

Anaemia

Hypertrophy

Question 9

What is unstable angina?

Answer 9

Stable angina that has recently progressed
The atherosclerotic plaque has been disrupted and caused a thrombus
High risk of acute MI

Question 10

What are the causes of sudden cardiac death?

Answer 10

Thrombosis
Arrhythmia
Spasm in cocaine use

Question 11

What is an MI?

Answer 11

Necrosis of the myocardium due to decreased blood supply

Question 12

What is the clinical presentation of an MI?

Answer 12

Crushing central chest pain

Weakness, nausea, sweating, vomiting

Question 13

What is the pathology of an MI?

Answer 13

Plaque rupture and thrombosis causes ischaemia

Begins subendocardium as that is furthest from blood supply

Question 14

What is used to diagnose MI?

Answer 14

ECG
Troponin
Creatine kinase

Question 15

What is troponin?

Answer 15

regulatory proteins of actin filaments in cardiac muscle

Released in any damage to heart, chemo, renal disease

Question 16

How long does it take for changes to be seen in the myocardium after an infarction?

Answer 16

10 hours

Question 17

What changes are seen in the myocardium after 1 day?

Answer 17

Coagulation necrosis
Hypereosinophila and wavy fibres (due to oedema)
Macroscopically heart is dark, red and firm

Question 18

What happens to the myocardium 2-7 days after an MI?

Answer 18

Signs of inflammation in nearby tissue: neutrophils and oedema
Patient might have high WCC and fever
Macroscopically tissue is soft and yellow

Question 19

What happens to the myocardium on days 7-14?

Answer 19

Dead tissue is resorbed and granulation tissue at edges

Macroscopically depressed area with red edges

Question 20

What happens to the myocardium on weeks 2-8?

Answer 20

Fibrosis and increased vascularity

Macroscopically tissue is grey/white

Question 21

How does the myocardium appear 8 weeks after an MI?

Answer 21

Dense fibrosis

Macroscopically a depressed thinned myocardium with a scar

Question 22

What are rare causes of coronary artery occlusion?

Answer 22

Vasculitis
Thrombus due to hypercoaguability
Trauma causing coronary dissection
Vasospasm

Question 23

What are the causes of sudden death in MI?

Answer 23

Ventricular fibrillation (especially with posterior inferior MI)
Cardiac tamponade

Question 24

What complications are associated with MI?

Answer 24

Arrhythmias within 48 hours
LV failure and pulmonary oedema
Cardiogenic shock
Ventricular rupture and haemopericardium
Chordae tendinae or papillary muscle rupture
LV aneurysm formation
Pericarditis and Dressler's syndrome

Question 25

What finding would be present in LV aneurysm formation?

Answer 25

2 apex beats

Question 26

What results from rupture through the ventricular wall post MI?

Answer 26

Haemopericardium and cardiac tamponade

Question 27

What results from rupture through the septum post MI?

Answer 27

Ventricular septal defect

Question 28

What results from rupture of the papillary muscle post MI?

Answer 28

Valve dysfunction and valve failure

Question 29

What are the signs of mild LV failure?

Answer 29

Sinus tachycardia

Question 30

What are the signs of moderate LV failure?

Answer 30

Dyspnoea and evidence of pulmonary oedema

Question 31

What are the signs of severe LV failure?

Answer 31

Cardiogenic shock Hypotension Poor tissue perfusion Reduced ejection fraction on ECHO

Question 32

What type of MI is associated with pump problems?

Answer 32

Anterior MI

Question 33

What type of MI is associated with conduction problems?

Answer 33

Posterior MI

Question 34

What conditions are under the term chronic ischaemic heart disease?

Answer 34

Angina and progressive heart failure

Question 35

What can be seen in chronic ischaemic heart disease?

Answer 35

Hypertrophy Dilation Narrow CA Myocardial fibrosis

Question 36

What drug is used for the primary prevention of chronic ischaemic heart disease?

Answer 36

Statins

Question 37

What interventions are used to treat a STEMI?

Answer 37

Percutaenous coronary intervention | Thrombolysis