Myocardial Infarction Flashcards
1
Q
What is an acute coronary syndrome?
A
Any acute presentation of coronary artery disease
2
Q
What are the two types of MI?
A
ST elevation MI - STEMI
Non ST elevation MI - NSTEMI
3
Q
Give three acute coronary syndromes?
A
- Unstable angina
- MI sudden
- Cardiac death
4
Q
Give 3 features of acute coronary syndrome?
A
- Dynamic stenosis
- Supply led ischaemia
- Unpredictable/dangerous
5
Q
How is thromboxane A2 generated?
A
Via cyclooxygenase from platelet membrane lipids
6
Q
What do both ADP and thromboxane A2 do to platelets?
A
Cause further activation and recruitment
7
Q
What type of angina has fixed stenosis, demnad led ischaemia and is predictable/safe?
A
Chronic stable angina
8
Q
What part of the plaetelt cascade involves unactivated platelets rapidly being recruited and adhering to the site of vascular damage, forming a monolayer?
A
Adhesion
9
Q
During release of activators in the platelet cascade, what is released from platelet dense granules?
A
ADP
10
Q
What does platelet activation accelerate?
A
Platelet aggregation
11
Q
Activation of platelets trigger the inflammatory cascade, what do activated platelets express for leukocytes?
A
Adhesion receptors
12
Q
Name two platelet sufacr inflammatory markers?
A
CD40L and P-selectin
13
Q
What platelet leukocyte conjugates, forming via P-selectin interact with?
A
Its ligand PSGL-1 on leukocyte surface
14
Q
What three things does CD40L interact with?
A
Monocytes, endothelial cells and smooth muscle cells
15
Q
What condition is prolonged, and not relieved by GTN, it is associated with sweating nausea an often vomiting?
A
MI
16
Q
What ivestigation is used to diagnose STEMI?
A
ECG
17
Q
What three ECG changes are seen in acute ST elevation myocardial infarction?
A
- ST elevation
- T wave inversion
- Q waves
18
Q
What ECG change is seen after the first few hours of an acute MI?
A
ST elevation
19
Q
What ECG change is seen after the first day of an acute MI?
A
Q wave formation and T wave inversion
20
Q
What ECG changges are seen in an old MI?
A
Q waves +/- inverted T waves
21
Q
What are the three features for confirming diagnosis of a STEMI on an ECG?
A
- > 1mm ST elevation in 2 adjacent limb leads
- > 2mm ST elevation in at least 2 contiguous precordial leads
- New onset bundle branch block
22
Q
What are the leads for an inferior MI?
A
II, III, AVF
23
Q
What are the leads for an anteroseptal MI?
A
V1-V4
24
Q
What are the leads for an anterolateral MI?
A
I, AvL, V1-6
25
Could cardiac enzymes and protein markers for an MI be normal at presentation?
Yes
26
What 2 substances would you look for when diagnosing an MI?
Creatinine Kinase - CK
| TnT - troponin T
27
When does creatinine kinase peak after an MI, and where is it also found?
Peaks in 24 hours
| Found in skeletal muscle and brain
28
What substance can detect tiny amounts of myocardial necrosis and is hughly specific for cardiac muscle damage?
TnT
29
What are the 7 treatments for early treatment of a STEMI?
1. Analgesia - dimorphine IV
2. Anti-emetic - IV
3. Aspirin - 300mg and Clopidogrel 300mg
4. GTN if BP>90mmHg
5. Oxygen - if hypoxic
6. Primary angioplasy
7. Thrombolysis - if angioplast is not available within 90 minutes
30
How does Aspirin work?
Inhibits COX preventing the production of prostaglandin and thromboxane A2 fro arachidonic acid.
31
What does TXA2 aid the expression of, allowing fibrinogen to bind?
GP IIb/IIIa binding site on the platelet, allowing fibrinogen to bind
32
How does Clopidogrel work?
It is a potent inhibitor of ADP-induced platelet aggregation, irreversibly inhibiting the binding of ADP to its platelet membrane receptors.
33
In addition to long term aspirin, what should be continued for up to four weeks in patients with ST elevation acute coronary syndrome?
Clopidogrel
34
Give two reperfusing therapies?
1. Thrombolysis
| 2. PCI
35
What are the two indications for reperfusion therapy (thrombolysis or PCI)?
1. Chest pain suggestive of acute MI - more than 20 minutes less than 12 hours
2. ECG changes - acute ST elevation, new LBBB
36
Name an arrhythmic complication of an MI?
Ventricular fibrillation
37
Give three structural complications of an MI?
1. Cardiac rupture
2. Ventricular septal defect
3. Mitral valve regurgitation
38
What are left ventricular aneurysm formation, mural thrombus (+/- systemic emboli), inflammation, acute pericarditis and Dressler's syndrome?
Structural complications of an MI
39
Give three functional complications of an MI?
1. Acute ventricular failure
2. Chronic cardiac failure
3. Cardiogenic shock
40
What is the killip classification of in-hospital mortality?
I - no signs of heart faILURE 6%
II - crepitations 50% of lung fields 38%
IV - cardiogenic shock 81%
41
In ACS with unstable angina, what can be said about the marker, ECG and LV function?
Marker: Tn & CK-MB undetectable
ECG: ST decreased or T decreased or transient ST increase or normal
LV function: no measurable dysfunction
42
What can be said about markers in ACS with myocyte necrosis?
Troponin elevated
| TnT
43
What can be said about markers, ECG, pathology and LV function of ACS with clinical MI?
Markers: TnT > 1.0 +/- CK-MB increased, or AccuTn > 0.5
ECG: ST increased or ST decreased or T wave inversion, may evolve Q waves
Pathology: complete coronary occlusion
LV function: systolic dysfunction, LV dilatation
44
What is raised in CCF, hypertension, renal failure, PE, sepsis, stroke/TIA, pericarditis/myocarditis and post arrhythmia?
TnT
45
What is the final common pathway to platelet aggregation?
GP IIb-IIIa
46
What should patients with non-ST elevation ACS at medium or high risk of early recurrent CVS events undergo?
Early coronary angiography and revascularisation
47
What is another term for congestive cardiac failure (CCF)?
Heart failure
48
What is heart failure due to in most cases?
Low cardiac output
49
What are the signs and symptoms of heart failure due to?
Fluid retention
50
What three conditions are a result of Left sided heart failure?
1. IHD = MIs
2. Cardiomyopathy
3. Valvular disease
51
What two conditions are a result of right heart failure?
1. Cor pulmonale
| 2. Congenital heart disease
52
Give 4 symptoms of left heart failure?
1. Dyspnoea on exertion
2. Orthopnoea
3. Paroxysmal nocturnal dyspnoea
4. Pulmonary oedema (pink, frothy sputum)
53
What is a gallop rythm?
S3 + tachycardia
54
Give 4 signs of left ventricular failure?
1. Tachycardia
2. Fine crepitiations
3. Pleural effusion
4. S3
55
What is a symptom of right heart failure?
Oedema
56
What are three signs of right heart failure?
1. JVP elevated
2. Hepatomegaly
3. Ascites
57
What is the CXR like with right heart failure?
Normla
58
What are the two treatments for Cor Pulmonale?
1. Diuretics
| 2. Oxygen
59
What is the treatment for valvular disease?
Surgery
60
What is the treatment for fast AF?
Digoxin or DC shock
61
What two conditions would you start standard medical therapy for CCF?
Previous MIs
| Cardiomyopathies
62
What are the 4 main drugs used in standard medical treatment for CCF?
1. Diuretics - excrete retained fluid
2. ACE inhibitors
3. Beta blockers
4. Spironolactone (severe cases only)
63
What are two lesser used drugs for Standard medical treatment for CCF?
1. Digoxin
| 2. Other vasodilators (nitrates, hydralazine)
64
What are three non pharmacological treatments (standard medical for CCF)?
1. Implantable cardiac defibrillators
2. Cardiac resynchronisation therapy
3. Transplantation
65
What diuretics are used for mild CCF?
Thiazide diuretics
66
What two coincidental drugs help retain and normalise K?
ACE inhibitors and spironolactone
67
What are captopril, enalapril and lisinopril?
ACE inhibitors
68
What are three side effects of ACE inhibitors?
1. Angioneurotic oedema
2. First dose hypertension (esp if serum Na low)
3. Renal impairment - UE must be monitored after ACE inhibiters start)
69
What are losartan and valsartan?
ARBs
70
What is a beta-1 selective beta-blocker?
Bisoprolol
71
What is a non-selective plus alpha blockade beta-blocker?
Carvedilol
72
What are hypotension nad worsening dysponoea two initial risks of?
Beta-blockers
73
Name an aldosterone receptor antagonist used in severe CCF?
Spironolactone
74
Give three side effects of spironolactone?
1. Hyperkalaemia
2. Renal dysfunction
3. Gynaecomastia
75
What drug slows heart rate but should only be used if HR is fast, despite beta-blockers?
Ivabradine
76
What is used only for prolonged QRS and involves 3 pacemakers inserted to force LV and RV to contract together?
Cardiac Resynchronisation Therapy
77
What drug is excreted slowly by kidneys and has a narrow therapeutic window?
Digoxin
78
What is digoxin used for?
AF but mediocre therapy for CCF in sinus rhythm
79
What are nausea, vomiting, bradycardia, heart block, arrythmia (VT, PAT) all side effects of?
Digoxin
80
4 management steps in acute LVF.
1. Sit up
2. Oxygen
3. IV furosemide
4. IV diamorphine - not in COPD
81
What condition should diuretics not be used in?
Gout
82
What is general therapy for an MI (MONA + C)?
Morphine (plus anti-emetic i.e. metoclopramide or cyclizine)
Oxygen (pulse ox>90% classI)
Nitroglycerin (SL GTN x 3 for iscaemic pain)
Aspirin 300mg + clopidogrel 600mg
83
How should aspirin be taken in pateints who have not taken aspirin vefore presentation with STEMI?
Chewed
84
What theraoy should be initiated in the first 24 hours for patients who do not have signs of heart failure, evidence of low output state, increased risk for cardiogenic shock or relative contraindications ro beta-blockade?
Betablockers
85
How fast should STEMI patients presenting to a hospital with PCI capability be treated with primary PCI?
Within 90 minutes
86
What therapy should STEMI patients presenting to a hospital without PCI capability, and who cannot be transfered to a PCI center and undergo PCI within 90 minutes of first medical contact get?
Fibrolytic therapy within 30 minutes
87
What are three opiate side effects?
Sedation, hypoventilation and nausea
88
After an MI, how often should patients be active for a day?
20 - 30 minutes
89
All patients who have had an acute MI should receive what 4 drugs?
Statin
ACE inhibitor
Beta-blocker
Aspirin
90
What combination of drugs should be given after non-ST-segment elevation MI?
Aspirin and Clopidogrel
91
For post MI patients with symptoms or signs of heart failure and LVSD what should they be offered and within how long of the acute MI?
Aldosterone antagonist within 3-14 days of an acure MO
92
Would recent aggresive CPR contraindicate thrombolytic therapy?
Yes
93
Is there risk of systemic embolism with AF?
Yes
94
What is the characteristic ECG sign of myocardial ischaemia?
The development of ST segment depression on exercise
95
What does the ECG in complete 3rd degree heart block show?
Dissociated ventricular and atrial activity
96
Can drug therapy cause VT?
Yes
