Lecture 18

Question 1

What is acute coronary syndrome?

Answer 1

Signs and syndromes (unstable angina/STEMI/nonSTEMI) due to decreased blood flow in the coronary arteries, due toa ruptured atheromatus plaque and thrombus formation

Question 2

What types of ECG can be viewed in acute coronary syndrome and what is the effect?

Answer 2

ST elevation: full occlusion

• mycardial damage= STEMI
• no damage= aborted STEMI

NO ST elevation: partial occlusion
(ST depression/T wave inversion)
-myocardial damage= NSTEMI
-no damage= unstable angina

Question 3

What is the definition of an acute myocardial infarction?

Answer 3

Cardiomyocyte necrosis in a clinical setting consistent with acute myocardial ischaemia

Question 4

What are some of the criteria for diagnosis of an acute MI?

Answer 4

• symptoms of ischaemia
• ST/T wave changes
• left bundle branch block
• pathological Q waves
• intracoronary thrombus detected on angiography/autopsy
• regional wall motion abnormality

Question 5

How many types of MI are there, and define the first 2?

Answer 5

5 types
Type 1
-atherosclerotic plaque rupture/ulceration/fissure/erosion/dissection resulting in an intraluminal thrombus in a coronary artery leading to decreased myocardial blood flow and subsequent myocardial necrosis
Type 2
-condition other than a coronary plaque that contributes to an imbalance between myocardial oxygen supply and demand

Question 6

Give some mechanisms resulting in type 2 MI:

Answer 6

• coronary artery spasm
• coronary endothelial dysfunction
• tachyarrhythmias, bradyarrhythmias
• anaemia
• respiratory failure
• hypotension
• severe hypertension

Question 7

What do you need to ask about when taking the history?

Answer 7

• cardiac sounding
• where does the pain radiate to
• how long did the pain last
• is the pain getting worse
• is pain worse on inspiration (pleuritic)
• relieved with GTN? (glyceryl trinitrate- quick pain disappearing= cardiac problem)

Question 8

What is the purpose of GTN?

Answer 8

Spray used to relieve angina by dilating blood vessels

Question 9

What risk factorsdo you look for in a patient with suspected heart problems?

Answer 9

• smoker/vape
• family history
• high cholesterol
• hypertension
• thrombophilia

Question 10

On examination of the patient what should you examine to do with haemodynamics?

Answer 10

• BP
• tachy/bradycardia
• JVP (jugular venous pressure)
• lungs (clear/wet- cracks= pulmonary oedema)
• heart sounds (mumur)
• cool peripheries

Question 11

What BP is classed as cardiogenic shock?

Answer 11

<90 mmHg

High chance that patient will deteriorate and die

Question 12

What are the ECG territories/location of infarct?

Answer 12

Lateral: V5, V6
Septal: V1, V2
Anterior: V1-V6
Anteroseptal: V1-V4
Anterolateral: V3-V6
Inferior: lead 2/lead 3, aVF
High lateral: lead 1, aVL

Question 13

What does ST elevation imply?

Answer 13

Sudden occlusion

Question 14

What does ST depression/T wave inversion imply?

Answer 14

Under-supply of blood to myocardium but not sudden coronary occlusion
(ST depression can also be caused by sudden occlusion of vessel at back of heart: posterior STEMI)

Question 15

What are the ECG signs evolving with ST elevation?

Answer 15

• hyperactue T waves (more prominent with wider base)
• ST segment elevation
• T wave inversion
• pathological Q waves

Question 16

What is raised in coronary syndromes?

Answer 16

Troponin I/T

Raised within 3 hours of cardiac damage and stay elevated for 2+ weeks

Question 17

What is an echocardiogram?

Answer 17

Ultrasound to image the heart (can be mobile)

• looks at it upside down
• coronal territory models

Question 18

What can you view using an echocardiogram?

Answer 18

• LV function
• wall motion
• valvular disease
• complications from an MI
• ventricle septal defect

Question 19

How do you manage a STEMI?

Answer 19

• aspirin 300mg
• second antiplatelet (ticagrelor: 180mg/prasugrel: 60mg)
• morphine 5-10mg with metaclopramide 10mg IV
• nitrate 2 puffs under tongue if BP >110 mmHg
• oxygen if <92%
• transfer for PCI

Question 20

At what weight/age do you give a second antiplatlet?

Answer 20

> 60 kg

<75 yo

Question 21

How do you manage an NSTEMI?

Answer 21

• antiplatelets/antithombotics (aspirin and clopidogrel/ticagrelor)
• anti-ischaemics (GTN infusion, bisopolol)
• secondary prevention

Question 22

What are some methods of secondary prevention of a NSTEMI?

Answer 22

• statins (reduce cholesterol)

- ACE inhibitors

Question 23

When would you do an urgent PCI?

Answer 23

NSTEMI

• patient has ongoing chest pain with dynamic ECG changes (changes from normal to abnormal suddenly)
• if patient develops arrythmias with compromise

Question 24

What is a PCI?

Answer 24

Percutaneous coronary intervention

• local anesthetic
• 30 mins
• radial/femoral artery access

Question 25

What is an invasive coronary angiogram?

Answer 25

X-Ray dye: contrast to opacitise coronary arteries to seeif there is an occlusion
If so:
-predilate the narrowed sections with balloons
-stent (metal scaffold) used to keep vessel patent

Question 26

What is the management after a PCI?

Answer 26

• Lifestyle changes (low fat diet/regular exercise/low salt)
• Dual antiplatelets for a year and then aspirin for life
• statins to reduce cholesterol to <4mmol/L (LDL conc <2mmol/L)
• bisprolol to keep HR at 70bpm (beta blocker)
• ACE inhibitor to keep BP 140/80
• echo shows EF is <40% then give eplerenone
• echo at 3 months if ejection fraction is <35%= implantable cardiac defibrillator

Question 27

What is the effect of beta blockers?

Answer 27

HR to fall with less contraction, therefore lowering BP

block effects of adrenaline