STEMI/NSTEMI

Question 1

pathophysiology of stable angina

Answer 1

fixed stenosis
demand led ischaemia
atherosclerotic plaque

Question 2

what is meant by acute coronary syndrome (ACS)

Answer 2

any acute presentation of coronary artery disease
provisional diagnosis that covers a spectrum of conditions
e.g. unstable angina, MI

Question 3

pathophysiology of ACS

Answer 3

fibrous plaque
plaque ruptures/fissure and thrombosis
dynamic stenosis (subtotal or complete occlusion)
supply led ischaemia

Question 4

platelet cascade - initiation

Answer 4

vascular damage (spontaneous plaque rupture)
exposing subendothelial collagen and von Willebrand factor

Question 5

factors affecting plaque rupture/fissure

Answer 5

lipid content of plaque
thickness of fibrous cap
sudden changes in intraluminal pressure or tone
bending and twisting of an artery during each heart contraction
plaque shape
mechanical injury

Question 6

platelet cascade - adhesion

Answer 6

platelet recruitment and adhesion at site of injury forming a monolayer
adhesion leads to activation

Question 7

platelet cascade - release of activators

Answer 7

ADP and other activators are released through degranulation
thromboxane A2 is generated via cycloxygenase
ADP binds to ADP receptors on circulating platelets and platelet activation accelerates - resulting in platelet aggregation (process that must be managed)

Question 8

platelet cascade - activation of platelet

Answer 8

activated platelets trigger inflammatory cascade

activated platelets express adhesion receptors for leukocytes

Question 9

symptoms for MI

Answer 9

severe crushing central chest pain, may come on at rest
radiates to jaw and arms, especially the left
similar to angina but more severe, prolonged (30 mins or longer) and not relived by GTN
associated with sweating nausea and often vomiting

Question 10

ECG changes in MI

Answer 10

ST elevation (STEMI) - first few hours
T wave inversion - first day
Q waves - first day

Question 11

ECG changes in STEMI

Answer 11

> 1mm ST elevation in 2 adjacent limb leads
2 mm ST elevation in at least 2 contiguous precordial leads
new onset bundle branch block

Question 12

ECG leads corresponding to inferior MI

Answer 12

II
III
aVF

Question 13

ECG leads corresponding to anterior MI

Answer 13

V1-V6

Question 14

ECG leads to corresponding to anteroseptal MI

Answer 14

V1-V4

Question 15

ECG leads to corresponding to anterolateral MI

Answer 15

I
aVL
V1-V6

Question 16

cardiac enzymes and protein markers for diagnosis

Answer 16

indicate cardiac injury (necrosis)
enzyme - CK (creatinine kinase)
protein marker - Tn (troponin)

Question 17

treatment for MI

Answer 17

Morphine - diamorphine (+anti-emetic)
Oxygen - if hypoxic 
Nitrate - GTN
Aspirin 
Clopidegrel 

PCI (90 minutes)
thrombolysis (120 minutes)

Question 18

risks of thrombolysis

Answer 18

failure to re-perfuse
haemorrhage - minor, major, intracranial haemorrhage
hypersensitivity

Question 19

complications of MI

Answer 19

death
arrhythmic complications
structural complications
functional complications

Question 20

arrhythmic complications of MI

Answer 20

ventricular fibrillation

Question 21

structural complications of MI

Answer 21

cardiac rupture
ventricular septal defect
mitral valve regurgitation 
left ventricular aneurysm formation
mural thrombus +/- systemic emboli
inflammation
acute pericarditis 
dressler's syndrome

Question 22

functional complications of MI

Answer 22

acute ventricular dysfunction (left, right or both - biventricular failure)
chronic cardiac failure
cardiogenic shock

Question 23

killip classification in-hospital mortality

Answer 23

I - no sings of HF
II - crepitations <50% of lung fields
III - crepitations >50% of lung fields
IV - cardiogenic shock

Question 24

ECG findings in NSTEMI

Answer 24

may be normal!

Question 25

differential diagnosis of elevated troponin levels

Answer 25

``` MI CCF hypertensive crisis renal failure PE sepsis stroke/TIA pericarditis/myocarditis post arrhythmia ```

Question 26

type I MI

Answer 26

spontaneous MI related to isachaemia due to primary coronary event such as plaque erosion and/or rupture, fissuring or dissection

Question 27

type II MI

Answer 27

``` MI secondary to ischaemia due to imbalance of oxygen supply and demand; increase - sustained tachycardia hypertension left ventricular hypertrophy hypertrophic cardiomyopathy valvular disease ``` ``` decrease; anaemia hypoxia bradycardia hypotension vasospasm coronary embolism ``` poor prognosis

Question 28

class III MI

Answer 28

sudden unexpected cariac death, including cardiac arrest, often with symptoms suggesting ischaemia with new ST-segment elevation, new left bundle branch block, or pathologic or angiographic evidence of fresh coronary thrombus - in the absence of reliable biomarker findings

Question 29

features of type I MI

Answer 29

``` sudden symptoms major ECG changes no other obvious cause high troponin rise then fall severe CAD on angiography ```

Question 30

features of type II MI

Answer 30

``` less chest pain minor ECG changes tach/low BP/illness smaller more static troponin levels mild moderate coronary disease ```

Question 31

describe non ischaemic myocardial injury with necrosis

Answer 31

occurs in complex, seriously unwell patients with significant medical or surgical issues patients have no evidence of significant coronary artery disease absence of ischemic symptoms or ECG chnages hard to diagnose either type I or II MI

Question 32

conditions associated with non ischaemic myocardial injury with necrosis

Answer 32

cardiac injury not related to myocardial ischaemia; cardiac contusion, ablation, pacing, AICD shocks myocarditis, cardiotoxic, chemotherapy multi-factorial or indeterminate myocardial injury; Severe sepsis or respiratory failure PE Pulmonary Hypertension, Cor Pulmonale Chronic severe heart failure, Chronic Renal failure Severe acute neurological diseases (stroke, subarachnoid) Exercise, Burns Stress (Takotsubo) cardiomyopathy

Question 33

treatment post MI

Answer 33

anti-platelet - aspirin/clopidogrel beta-blocker - atenolol/bisorpolol ACE - ramipril/perindopril statins - simvastatin/atorvastatin