Stroke, atherosclerosis, oedema, arrhythmias and valve disease Flashcards
(155 cards)
1
Q
Define red and white thrombi (origin and composition)
A
- Red thrombus: contains mostly RBCs and fibrin. Venous origin, caused by stasis or hypercoagulability
- White thrombus: contains lipids/platelets and fibrin. Arterial origin, broken off atheroma plaque
2
Q
What are the three components of Virchow’s triad?
A
- Change in blood flow (ie stasis)
- change in blood components (ie hypercoagulability)
- change in blood vessel (ie endothelial damage)
3
Q
What investigations should be done to diagnose pulmonary embolism?
A
- If Wells probability score low - do a blood test for D-Dimer
- If Wells probability score high - do CT Pulmonary Angiogram
If D-Dimer positive - do CT Pulmonary Angiogram
4
Q
What are the two main types of Venous Thromboembolism (VTE)?
A
Deep vein thrombosis (DVT) and Pulmonary Embolism (PE)
5
Q
Define embolism
A
Material in the circulation which dislodges from original place and moves to another area of the body. Can be a blood clot but also air, lipids etc
6
Q
What are two causes for stasis (blood pooling, change in blood flow in Virchow’s triangle)?
A
Long flights, immobility/bedbound status
7
Q
What can cause hypercoagulability?
A
Inherited or acquired (Pregnancy, surgery, cancer)
8
Q
What can cause endothelial damage?
A
Endothelial dysfunction (caused by smoking, hypertension, hypercholesterolaemia) Endothelial injury (IV catheters, trauma, surgery)
9
Q
What are common signs of DVT?
A
Unilateral swelling, discomfort, redness, may be silent
10
Q
Define claudication
A
Pain in leg(s) due to ischaemia caused by occluded artery supplying the leg.
11
Q
What is a common complication of DVT and what are its implications?
A
Post-thrombotic syndrome, can affect up to half the patients who have had DVT in previous months.
Causes chronic pain, swelling, redness, ulcers and damage to valves in the veins
12
Q
How is DVT diagnosed?
A
- Clinical assessment and Wells score
- Wells test result low –> blood test for D-Dimer
- Wells test high/D-Dimer positive –> compression ultrasound or doppler ultrasound
13
Q
What is the Wells probability test?
A
It’s a measure to calculate the risk of thrombosis based on risk factors
14
Q
What is a D-Dimer?
A
It’s a byproduct of the breakdown of cross-linked fibrin following fibrinolysis
15
Q
What are the diagnostic advantages and disadvantages of D-Dimer blood testing?
A
It’s very sensitive to D-Dimer presence in the blood, so useful to rule out thrombosis.
It’s not very specific, there are other causes for raised D-Dimer levels so a positive result may not be due to thrombosis
16
Q
What are the four main types of valve disease?
A
Mitral stenosis,
Mitral regurgitation,
Aortic stenosis
Aortic regurgitation
17
Q
Which heart valves are more likely to have congenital abnormalities?
A
Right heart valves - tricuspid and pulmonary
18
Q
What are the main causes of mitral stenosis?
A
Rheumatic heart disease Systemic diseases (SLE, RA) Congenital defect
19
Q
What are the main symptoms of mitral stenosis?
A
Shortness of breath (exertion) Shortness of breath (pulmonary oedema) Haemoptysis Hoarse voice (compressed recurrent laryngeal nerve) Infective Endocarditis
20
Q
What are the main signs of mitral stenosis?
A
Mitral facies RV hypertrophy Pulmonary oedema Pulmonary hypertension Raised JVP (a wave) Tapping apex beat Diastolic thrill
21
Q
Which valve diseases have a long asymptomatic phase?
A
Aortic stenosis and aortic regurgitation
22
Q
What investigations can be done to diagnose mitral stenosis?
A
Cardiac catheter CXR ECG Echocardiogram Cardiac magnetic resonance
23
Q
What are the steps in diagnosing Pulmonary Embolism?
A
Wells score low - D-Dimer
D-Dimer positive - CT Pulmonary Angiogram, V/Q scan
Wells score high - CT Pulmonary Angiogram, V/Q scan
24
Q
What are the common signs and symptoms of PE?
A
Pleuritic chest pain, SOB, tachycardia, haemoptysis, pleural rub
If PE severe: severe SOB, central cyanosis, low BP, raised JVP, sudden death
25
What are the main treatment options for Vascular Thromboembolism (VTE)?
Anticoagulants (fractionated or LMW heparin; warfarin, DOACs)
Thrombolysis (eg alteplase, in severe cases)
26
What measures can be taken to prevent VTE occurring?
Early mobilisation, stockings, mechanical or pharmaceutical thromboprophylaxis
27
What are the main aims of VTE treatment?
Prevent recurrence, prevent clot extension and further embolisation
28
What is a possible long term complication of PE?
Pulmonary hypertension
29
How can PE lead to pulmonary infarction, and how likely is it?
Infarction rare due to collateral circulation in lungs.
| It occurs through leaking fluid into alveoli due to increased pressure in bronchial circulation
30
What are three important considerations when VTE has been diagnosed?
- Clear cause of VTE (eg recent surgery, long flight)
- Signs or symptoms indicating underlying malignancy
- Chance of recurrence
31
What are the common causes of abdominal aortic aneurysms?
- Atherosclerosic disease
- Connective tissue diseases (eg Marfan's Syndrome)
- Infection
32
What are common risk factors for aneurysms?
Same ones as for atheromatous plaques:
| Hypertension, age, smoking, diabetes, family history, high cholesterol, males
33
When should surgical repair of aneurysm be considered?
If aneurysm is enlarged to >5.5cm
34
What are the most common presentations of aneurysm?
Nothing, it's normally picked up incidentally (especially through ultrasounds for gallstones). May present as back pain
35
What is the purpose of screening for aneurysms?
It helps to identify aneurysms before they rupture and monitor ones which are not large enough to call for repair
36
If an abdominal aortic aneurysm measuring 3-4.5cm is found, what is the course of action?
Patient should be discharged an be invited back for yearly ultrasound scans to monitor the aneurysm
37
If an abdominal aortic aneurysm measuring 4.5-5.5cm is found, what is the course of action?
Patient should be discharged and be invited back every 3 months for a surveillance ultrasound scan
38
What are common presentations of a ruptured abdominal aortic aneurysm?
Shock
back/side/abdominal pain
haematodynamic instability
hypoperfusion
39
What are some less common presentations of a ruptured abdominal aortic aneurysm?
```
Distal embolisation (toes, kidneys, colon)
compression of duodenum
compression of ureter
aortocaval fistula
aortoenteric fistula
```
40
What are the surgical repair options for a ruptured abdominal aortic aneurysm?
Open repair or endovascular repair (EVAR)
41
What imaging techniques are used for assessing abdominal aortic aneurysm size, and what are their pros and cons?
Ultrasound:
Pros: cheap, accessible, tolerated by patient
Cons: operator dependent, no anatomic detail
CTA/MRA scan:
Pros: very quick (30s), not operator dependent, very clear anatomic image
Cons: radiation and contrast
42
What factors should be considered when assessing surgical repair for abdominal aortic aneurysm?
Patient fitness (lung, heart, kidney function)
Patient wishes
Aneurysm size
Anatomy (determines which type of surgery is suitable)
43
What are three main treatment options for abdominal aortic aneurysms?
Conservative treatment
Endovascular repair (EVAR)
Open repair
44
List some of the complications of open repair for abdominal aortic aneurysms
Pain/scarring/bleeding/dehiscence/wound infection
Damage to structures adjacent to aorta (nerves, bowel, veins, ureter)
distal embolisations and ischaemia, graft infection
colon ischaemia (redundant inferior mesenteric artery), kidney damage,
CVA/MI/PE
45
List some of the complications of EVAR for abdominal aortic aneurysms
```
Pain/scar/bleeding/wound infection
Endoleak
Damage to endothelium (femoral dissection, pseudoaneurysm)
distal embolisations, graft infection,
CVA/MI/PE
```
46
What is an endoleak?
It's blood leakage in the area of the aneurysm that has been grafted
47
What investigation should be done to assess whether an aneurysm rupture should be repaired with open repair or EVAR?
CT scan to assess anatomic suitability for EVAR
48
When is an endarterectomy performed?
When a patient has/has had TIA/stroke symptoms and the relevant carotid artery is >70% but <99% occluded
49
What course of action should be taken if one carotid artery is completely occluded?
Best medical care (BMC), operation will not benefit patient since other arteries are still supplying Circle of Willis
50
What investigations should be done when a patient presents with a stroke?
CT scan - rule out a haemorrhagic stroke
| Doppler ultrasound - to assess degree of carotid stenosis
51
What is the main management aim of TIA/stroke, and what are the common management steps?
Management to reduce risk factors:
- smoking cessation
- antiplatelet (2x for first 3 months)
- statin
- blood pressure medication
- diabetic control
52
What investigations should be carried out to diagnose stroke/TIA?
```
History
examination
bloods (FBC, lipids)
ECG (24hr)
CT/MRI
carotid ultrasound scans
```
53
What are the possible complications of an endarterectomy?
Bleeding, scarring, pain, infection
anaesthetic complications
damage to recurrent laryngeal nerve
perioperative stroke (thrombosis, hypoperfusion)
54
What factors can influence the management decision for stroke? (ie endarterectomy or best medical treatment)?
```
Patient wishes
Anatomic suitability
Degree of carotid stenosis
Time since stroke/TIA
Females
```
55
When is the most beneficial time to carry out endarterectomy to reduce further events?
First 2 weeks post event (faster is better in women)
56
When would carotid stenting be considered in the prevention of stroke?
If patient is not anatomically suitable for endarterectomy (eg scarring or occlusion is further up the internal carotid artery)
57
What treatment will be offered to a symptomatic patient with 60% carotid stenosis, and to one with 75% carotid stenosis?
60% - best medical treatment only
| 75% - best medical treatment + endarterectomy (or stenting if anatomically unsuitable for endarterectomy)
58
What are the four main types of ischaemic stroke?
Total Anterior Circulation Stroke (TACS)
Partial Anterior Circulation Stroke (PACS)
Lacunar Stroke (LACS)
Posterior Circulation Stroke (POCS)
59
What is POCS most likely to present with?
```
visual disturbance (Homonymous hemianopia)
breathing problems
tinnitus
Horner's syndrome
loss of function/sensation
coma
dizzyness
balance problems
```
60
What is TACS most likely to present with?
Symptoms include face/arm/leg weakness and loss of sensation, speech disturbance, loss of vision
61
What is PACS most likely to present with?
Combination of 2/3 of the symptoms seen in TACS. Restricted hemiparesis/loss of sensation only, or speech/motor function disturbance only
62
What is LACS most likely to present with?
Depends on the location.
| Sensory only/motor only/sensorymotor/ataxic hemiparesis
63
What are the two main presentations of stroke and their prevalence?
```
Ischaemic stroke (85%)
Hemorrhagic stroke (15%)
```
64
Which type of stroke may go unnoticed and undiagnosed?
LACS
65
List some of the risk factors for stroke
```
Atrial Fibrillation
Smoking
Hypertension
Diabetes
Previous stroke/MI
Hypertension
Hypercholesterolaemia
Race
Family history
Age
Gender
```
66
What are the 5 main presenting characteristics of a stroke?
```
Loss of function
Loss of sensation
Loss of vision
Loss of balance
Loss of speech
```
67
What is the main cardiovascular cause for cardioembolic stroke?
Atrial Fibrillation
68
What is the main cardiovascular cause for haemorrhagic stroke?
Hypertension
69
What are the benefits of stroke units?
Expertise
Specialised care
Early mobilisation
Attention to improving functions eg swallowing, speech and language, rehabilitation
70
What is the benefit of informing A&E of stroke from ambulance?
Reducing time it takes to get patient into hospital, to CT and thrombolysed
71
What imaging investigation should be done when a patient presents with a stroke?
CT to rule out haemorrhage. If ischaemic, thrombolyse (tPA)
72
Why is it important to improve swallowing function in stroke patients?
To avoid choking or aspiration pneumonia
73
What type of stroke shows up best on CT scan?
Haemorrhagic stroke
74
What type of stroke shows up best on MRI scan?
Ischaemic stroke
75
What is the main complication of thrombolysis?
Bleeding
76
What seems to be the most effective way to treat a stroke in an emergency?
Thrombolysis + thrombectomy (clot retrieval) if ischaemic stroke
77
What are the contraindications for thrombolysis?
Age (>80)
Recent bleeding
severe hypertension
78
When should hemicraniectomy be considered?
- Patient is <60yo
- ischaemic MCA occlusion with cerebral oedema
- <48hrs from onset
79
What common antiplatelet drugs are used in secondary prevention of stroke?
Aspirin
Clopidogrel
Dipyridamole
80
What main treatment should be used for stroke prevention in patients with AF?
Anticoagulants
- warfarin
- DOACs (apixaban, rivaroxaban)
81
What is the main cause of atherosclerosis?
Hypercholesterolaemia
82
What is atherosclerosis?
Formation of atheromatous plaques in areas of damaged endothelium
83
What are atheromatous plaques made up of?
Inner mass of dead macrophages, cholesterol, lipids, calcium
| Outer cap made up of collagen and fibrous tissue (stimulated by PDGF)
84
What does complicated atheroma mean?
It's a rupture of an atheromatous plaque, which causes inflammation/thrombosis
85
What are the two types of supraventricular tachycardia?
- AV node re-entral tachycardia (extra conduction in atrial tissue)
- AV re-entral tachycardia (extra conduction from atrium to ventricle)
86
What characterises first degree heart block?
Slow conduction from sinoatrial node - long PR interval
87
What characterises second degree heart block?
Mobitz 1 - increasing delay in PR segment until one P wave doesn't conduct signal to ventricle
Mobits 2 - no pattern, random P waves do not conduct signal to ventricle (no QRS)
88
What characterises third degree heart block?
P waves have no association with the QRS waves, occur indepentently of eachother
89
What is the difference between atrial flutter and atrial fibrillation on an ECG?
Atrial flutter - sawtooth
| Atrial fibrillation - no P wave
90
What does Wolff-Parkinson-White Syndrome look like on an ECG?
Delta wave (slurred upstroke QRS, wide at the bottom and narrowing at the top)
91
How to tell supraventricular and ventricular tachycardia apart on an ECG?
Supraventricular tachycardia - narrow QRS
| Ventricular tachycardia - broad QRS
92
Define AV nodal re-rentrant and AV re-entrant supraventricular tachycardia
- AV nodal re-rentrant supraventricular tachycardia: conduction signal goes round in circles around the AV node
- AV re-entrant supraventricular tachycardia: conduction signal sent to ventricles but moves back to the atria through accessory conduction circuit
93
What are supraventricular ectopic beats?
Beats which come in earlier than they should
94
Define Torsades de Pointes
Polymorphic ventricular tachycardia
95
What are the main aims of atrial fibrillation treatment?
```
Heart rate control (beta blockers, rate limiting CCBs)
Rhythm control (drugs, cardioversion, RFA)
```
96
When should an internal defibrillator be inserted?
If VF/VT not secondary to reversible cause
If VT continuous and causing syncope or significantly reducing QoL
If VT and LV failure
97
When should a pacemaker be inserted?
If alternating LBBB and RBBB
If severe or at risk of severe bradycardia
If second or third degree heart block
98
What investigations should be carried out to diagnose AF?
```
24hr ECG
blood test (to exclude hyperthyroidism and electrolyte abnormality)
```
99
Which valve diseases can have a long asymptomatic period?
Aortic stenosis and aortic regurgitation
100
How do aortic stenosis and regurgitation affect the pulse on examination?
stenosis - rising pulse
| regurgitation - collapsing pulse
101
What are common causes of mitral stenosis?
Rheumatic heart disease
congenital
systemic diseases (SLE, RA)
102
What are common symptoms of mitral stenosis?
Haemoptysis
SoB
Pulmonary oedema
Systemic emboli (eg stroke)
103
What are useful investigations for diagnosing mitral stenosis?
Echocardiogram
Cardiac catheterisation (ie angiography)
Cardiac MRI
to a lesser extent: ECG, CXR
104
What medical treatments should be used for mitral stenosis?
Anticoagulants for AF
| Diuretics
105
What are common acute and chronic symptoms of mitral regurgitation?
acute - cardiogenic shock, severe SoB
| chronic - fatigue, SoB on exertion, PND
106
What are the main investigations carried out for mitral regurgitation?
Echocardiogram (transthoracic/transesophageal)
cardiac MRI
CXR
ECG
107
What are the medical treatment options for acute and chronic mitral regurgitation?
acute - medical emergency: dobutamine (for cardiogenic shock); sodium nitroprusside (vasodilator), keep patient alive until they can go to surgery
chronic - nothing proven effective
108
What are the medical treatment options for acute and chronic aortic regurgitation?
acute - medical emergency: dobutamine (for cardiogenic shock); sodium nitroprusside (vasodilator), keep patient alive until they can go to surgery
chronic - vasodilators
109
What are the medical treatment options for aortic stenosis?
None unless pt develops heart failure
110
What are the common symptoms of aortic stenosis?
Chest pain
Blackouts
SoB
111
Name two conditions which can lead to VT/VF
Brugada syndrome
| long-QT syndrome
112
What treatment is most successful in stopping supraventricular tachycardia (nodal re-entral or re-entral)?
Radiofrequency Ablation
113
What are two potential causes for long QT syndrome?
genetic
| acquired (eg drugs)
114
What is the definition of congestion?
Excess blood in systemic vessels
115
What is the definition of oedema?
Excess fluid in interstitial space
116
What are the effects of congestive heart failure?
Left heart failure: pulmonary oedema
| Right heart failure: central venous congestion + portal venous congestion
117
What are the consequences of central venous congestion?
raised JVP
hepatomegaly (hepatic central venous congestion)
peripheral oedema
118
What is the main process behind transudate oedema?
changes in hydrostatic pressure in capillaries
119
What is the main process behind exudate oedema?
increased capillary permeability as reaction to inflammatory process
120
What components of oedema can be used to characterise the underlying process, and how?
Transudate - few proteins, low gravity
| Exudate - lots of proteins, high gravity
121
What is the process underlying lymphoedema?
obstruction of lymphatic vessels
122
What are some examples of congestion in clinical practice?
DVT
Liver congestion in cirrhosis
Congestive heart failure
123
How does congestive heart failure arise, and what does it result in?
LV and/or RV not efficiently pumping blood out
LV - backlog and congestion in lungs = pulmonary oedema
RV - backlog and congestion in systemic veins and portal system = peripheral oedema and hepatomegaly
124
What can cause portal circulation congestion, and what are some potential consequences?
Portal systemic shunts:
- Oesophageal varices
- Caput medusae
125
How does LV failure cause oedema?
Reduced CO
Activation of RAAS
Increased water/salt retention
Fluid overload = oedema
126
What are the main forces controlling fluid in the vessels, and how do they lead to oedema?
- Hydrostatic forces: increased pressure in capillary due to congestion can force fluid out of vessel
- Oncotic forces: lack of proteins drawing fluid back into capillary can cause fluid buildup outside the vessel
127
How does lymphedema come about?
Blockage of lymphatic system at capillary bed
128
What type of oedema is found in congestive heart failure, and which starling force is at play?
Transudate oedema
| Hydrostatic force imbalance
129
What are starling’s forces and what is their function?
Hydrostatic pressure and oncotic pressure
| Keeps balance of fluid inside and outside capillary
130
At which point in circulation is hydrostatic or oncotic pressure higher?
Arterial circulation - hydrostatic force
| Venous - oncotic force
131
What are the two mainly occurring types of haemorrhagic stroke and their prevalence?
- Intracerebral haemorrhage (9%)
| - Subarachnoid haemorrhage (6%)
132
what are the two major ischemic heart conditions which call for CABG?
- left main stem stenosis
| - three vessel disease
133
what is meant by three vessel disease?
obstruction of the RCA, LAD and Cx
134
what is left main stem stenosis?
stenosis of the bifurcation of the LCA into LAD and Cx
135
What are three main complications of CABG surgery?
cardiac tamponade
stroke
death
136
what can be some complications of open heart surgery (sternotomy)?
```
infection of the wound/wires
sternal dehiscence (two sides grind agaisnt eachother)
sternal malunion (sternal sutures come apart)
```
137
what are the main vessels used as bypass grafts?
mammary arteries
radial artery
reversed saphenous vein
138
which valve diseases are most commonly operated on, and when should surgery be carried out?
Aortic most common, then mitral
if valve disease severe
if there is large vegetations on valves
if renal function keeps dropping or fever persists
139
what options of valve replacements can be used?
```
pig valve (biological)
mechanical valve
```
140
what are the benefits and disadvantages of the different types of replacement valves?
biological - less chance of infection; no warfarin; won't last as long
mechanical - higher chance of infection; makes noise; will last a lifetime but also be on warfarin for life
141
which two organisms are most likely to cause what severity of infective endocarditis?
strep viridans - subacute IE
| staph aureus - acute IE
142
what is a benefit of mitral valve repair over replacement?
it's better to keep as much of the native valve as possible
143
IE affecting which types of replacement valves is more and less likely to be cured by only antibiotics?
native replacement valve - 90% chance of cure with only antibiotics
prosthetic valve - 50% chance of cure with only antibiotics
144
what is the classification of anti-arrhythmic drugs called, and how does it classify the drugs?
Vaughan Williams Classification
Class 1 - (1a,1b,1c): sodium blockers
Class 2 - beta blockers (reduce sympathetic activity)
Class 3 - potassium channel blocker (longer repolarisation)
Class 4 - calcium channel blockers (rate limiting)
145
what are the possible side effects of digoxin?
yellow vision
brady/tachicardia
VF/VT
nausea and vomiting
146
what are the main drugs used to treat atrial fibrillation?
beta blockers
class 1a sodium channel blockers (quinidine)
anticoagulants (warfarin or DOACs)
147
when are drugs like flecainide and amiodarone used in arrythmias?
in serious SVT, VT or arrhythmias not responding to beta blockers
148
what is the mechanism of action of digoxin and which patient population is likely to be on it?
positive inotrope, blocks ATPase pump
| often given to elderly patients with kidney failure
149
what is the effect of the various sodium channel blockers on cardiac action potentials?
```
class 1a - longer AP, delay refractory period
class 1b - shorter AP, accelerate refractory period
class 1c - no effect on AP or refractory period, stronger sodium block
```
150
how is digoxin toxicity treated?
by stopping digoxin and administering Digibind
151
what are class 1b antiarrythmics used for?
severe VT and VF
152
give an example of antiarrhythmic medication for each Vaughan Williams classification
```
class 1a - quinidine
class 1b - lidocaine, phenytoin
class 1c - flecainide
class 2 - bisoprolol, atenolol
class 3 - amiodarone
class 4 - verapamil, diltiazem
```
153
how can warfarin be counteracted and why?
with vitamin K
warfarin stops vitamin K activation (which helps production of clotting factors) --> administering vitamin K increases its levels in the blood
154
what are possible side effects of warfarin?
bleeding
| teratogenicity
155
what is the effect of adenosine on paroxysmal ventricular tachycardia?
returns heart to sinus rhythm
