CLINICAL- STROKE Flashcards
What’s a cerebral infarct?
A type of stroke resulting from blockage in one of the blood vessels supplying blood to the brain. The blood supply to that part is lost resulting in death of the area.
It is different from cerebral hemorrhage or subarachnoid hemorrhage.
What is a cerebral heamorrhage?
Spontaneous bleeding into the brain tissue
Second most common cause of stroke
It’s NOT caused by a clot (so don’t use alteplase!)
What is a subarachnoid heamorrhage?
Bleeding into the subarachnoid space (outside of the brain, inside the skull)
Can be a cause of stroke
Can occur spontaneously or from head injury
What is the difference between ischemic stroke and hemorrhagic stroke? Which is most common?
Ischemic stroke occurs because if an obstruction in a blood vessel (e.g: cerebral infarct: clot in the brain blood vessels).
This is the most common kind of stroke
Heamorrhagic stroke occurs when a weak blood vessel ruptures. It can be a cerebral heamorrhage or a subarachnoid heamorrhage.
Causes of ischaemic stroke can be embolic or thrombotic. What are these?
Embolic is where the clot has come from elsewhere in the body and has broken off and blocked a vessel.
Thrombotic is where the blood vessel walls get narrower and narrower due to plaque formation/ atherosclerosis
Where are common locations for plaques/ thrombotic blockages to form??
Anywhere the blood vessels branch off.
Branches coming together
The circle of Willis: blood vessels that compensate for any narrowing or blockages in the the main blood vessels, blood can bypass the narrow vessel
When someone comes in with symptoms of stroke, we need to find out whether it’s a haemorrhagic stroke or an ischemic stroke so that we know whether we can give thrombolysis/ clot buster. How do we distinguish?
Do a CT scan
If someone’s had bleeding on the brain you can tell within 30seconds with a CT scan
Alteplase is the fibrinolytic drug of choice (clot buster) used in stroke. When is it not indicated?
After 4.5 hours from the onset of symptoms
Stoke is the 3rd most common cause of death after heart disease and cancer
Stroke is the most common cause of severe disability
After the acute treatment after a stroke has occurred, secondary prevention and rehabilitation (if needed) are started.
Rehabilitation helps with stroke related disability
In the primary prevention of stroke, what’s the mass population strategy??
Blood pressure
Smoking
Lipids (cholesterol)
In the primary prevention of stroke, what risks, part from the mass population ones (hypertension, smoking and cholesterol), are managed in the high risk strategy??
Diabetes
Atrial fibrillation
Other vascular diseases (e.g. Congestive cardiac failure, Myocardial infarction, carotid artery stenosis)
Previous TIA
What is a big risk factor for stroke in young men?
Binge drinking at the weekends
What risk factor contributes the most risk of stroke??
Hypertension!!
If you can get the diastolic BP to drop by just 7.5 mmHg, you’re looking at a 46% reduction in their likelihood of stroke
What can we give to patients with AF to reduce their likelihood of stroke by 60-80%??
Warfarin
Is stroke more common in men or women?
Men
The prevalence of stroke is increasing because….
People are living longer and longer, and stroke likelihood increases with age!!
What is a TIA?
Trans ischeamic attack It has a sudden onset- no warning signs Short lived Full recovery by one hour May have a single one or multiple over time
Mini stroke
Patients who have had a TIA are more at risk of a stroke because it indicates there was a temporary disruption in the blood supply to the brain so there must be something going on
(Like an earthquake leading to a volcanoe)
What could TIA be mistaken for??
Partial epileptic seizure Migraine with aura A Hypo Drunk/ on drugs! Hysteria
CT scan can be used to distinguish a TIA from cerebral heamorrhage, brain infection or injury but doesn’t help to exclude the possibilities above!!
In practice it is most important to distinguish between haemorrhage and ischeamic stroke, as their treatment is so different but their symptoms overlap
What is the Allen score used for?
Found to be 90% accurate in the identification of heamorrhage
Which type of stroke has HRT (hormone replacement therapy) not been associated as increasing the risk of?
Haemorrhagic stroke
It has been associated with total stroke, non fatal stroke, fatal stroke and ischeamic stroke
When should TIA patients get taken to hospital?
If symptoms are ongoing and have come on within the last 180 minutes they should go to hospital in an ambulance.
Patients that arrive within 180 mins (3 hours) of symptom onset should undergo examination as to whether they need thrombolysis.
If high risk- admit an thrombolysis
If low risk- TIA clinic
What scoring system is used to assess the risk of stroke after a TIA?
ABCD2 score
Age BP Clinical features Duration of symptoms Diabetes history
(See book)
What ABCD2 score classifies as high risk of stroke after TIA?
Score of 4 and above
Need to refer for specialist assessment within 24 hours!!
What does an ABCD2 score of 3 or below indicate??
Low risk of stroke after TIA
Refer for specialist assessment within 7 DAYS
In the ABCD2 scoring system what does symptoms lasting for under 10 minutes score?
Zero!
10-59 minutes scores 1
Over 60 minutes scores 2
The longer the symptoms last, the more likely you’ll have to go for specialist assessment more urgently!!
What does unilateral weakness score on the ABCD2 scoring system for TIA severity?
2
Speech disturbance without weakness scores 1
Fall under clinical features
What should patients with TIA immediately receive??
Anti platelet therapy: Aspirin 300mg STAT
(Allergic to aspirin or not tolerated with a PPI added go for clopidogrel 75mg OD but this is unlicensed!)
This is all in BNF under transient ischeamic attack in stroke section!!
How should aspirin and clopidogrel be prescribed following a STROKE?
Aspirin 300mg for 14 days
Then clopidogrel 75mg OD thereafter
We may be on this combo for CV disease as well! (Dual antiplatelet therapy post STEMI!) these patients: need dual therapy for 12 months after event, then usually just on aspirin, but in stroke patients maintain them on clopidogrel forever instead
What’s the difference in aspirin prescribed for TIA and for stroke?
TIA: it’s just a 300mg STAT dose (one day) then 75mg clopidogrel forever after
Stroke: 300mg aspirin OD for 14 days, then 75mg clopidogrel forever after
What’s the deal with blood pressure control in patients who have had a stroke or TIA?
They should be on BP medication unless their BP is really low.
Even if they are nomotensive, it would still be beneficial to lower their BP.
Statins reduce the risk of stroke occurring after TIA/ after a stroke.
What cholesterol level should we definitely consider Statin therapy for?
Over 5.2 mmol/L
How long after the acute phase of stroke should we wait until we start messing around with patients medication e.g. Introducing a Statin, increasing BP medication..?
Wait for 48 hours!
What is carotid artery stenosis??
Narrowing of the carotid artery (usually by atherosclerosis).
This is the large artery on either side of the neck
It bifurcates (splits in two) and this bifurcation is a common place for atherosclerosis to build up.
If it becomes completely blocked there is still the circle of Willis to compensate
Carotid artery stenosis can either present with no symptoms or with symptoms such as TIA’s or strokes
What is a carotid endarterectomy?
Carotid stenosis can occur where the carotid artery becomes narrow.
A carotid endarterectomy is a surgical procedure used to reduce the risk of stroke, by correcting the narrowing stenosis of the carotid artery by removing material from it: scraping it out!!! Or actually pulling the clot out of it…
The plaques that have built up in this artery can cause TIAs. Symptomatic stenosis has a high risk of stroke within the next two days
Are patients with a symptomatic carotid stenosis or unsymptomatic carotid stenosis more at risk of stroke??
Symptomatic
But unsymptomatic still at a higher risk than the general population
What is carotid stenting??
A stent, which is a mesh like tube, is inserted into the carotid artery to stop them getting any narrower or the plaque breaking down and causing blockage and a stroke
Patients with a ABCD2 score of __ or more with symptomatic _______ _____ can undergo brain imaging of their _____ artery after a TIA in order to determine whether they would benefit from ________ endarterectomy / a stent
4 or more
Symptomatic Carotid stenosis
Carotid artery
Carotid endarterectomy
How much more likely are you to have a stroke if you have AF?
5 times more likely
Incidence of AF rises rapidly with old age
Stroke incidence in AF also increased with age
What’s the deal with stroke and AF??
STROKE SURVIVORS WITH AF HAVE POORER OUTCOMES
Stroke in AF is more likely to result in death - double the mortality rate
Stroke in AF is more severe
Longer hospital stays, lower rate of discharge to home
AF patients face an increased risk of recurrent stroke
What is the CHA2DS2VASc criteria used for?
Stroke risk assessment in patients with AF!!
It’s a scoring system used to see if someone with AF should go on blood thinning treatment
What does each letter stand for in CHA2DS2 VASc??
C= congestive heart failure or left ventricular dysfunction H= hypertension (over 140/90) A= age (over 75) D= diabetes mellitus S= stroke or TIA (or thromboembolism) V= vascular disease (e.g. Previous MI, peripheral artery disease or aortic plaque) A= age 66-74 S= sex
What do AF patients score on CHA2DS2 VASc with diabetes?
1
How old do you have to be to score 2 on CHA2DS2 VASc for age?
75 or over
What does the S that scores 2 stand for on CHA2DS2 VASc ?
Stroke or TIA (previous history)
What does Sc stand for in CHA2DS2 VASc ?
Sex catergory
Female = 1
What’s the scoring system we use to assess bleed risk in stroke patients? What does each letter stand for
HASBLED Hypertension (systolic 160 or over) Abnormal kidney function or liver function (1 point each) Stroke history Bleed risk from medication Labile INR Elderly (over 65) Drug/ alcohol use (1 point for taking an antiplatelet drug like aspirin or plavix, 1 point for 8 or more alcohol drinks a week, 2 points for both)
All score 1 each
What CHA2DS2 VASc score is enough to get thrombo-prophylaxis treatment?
2 or more definately
1 we consider (in practice they usually always), don’t treat if they just got one for being female
Patients who have scored 2 or more on CHA2DS2 VASc are eligible for thromboprophylaxis, can we use antiplatelet drugs to anticoagulate?
NO!
Aspirin etc ineffective in AF
This is because in AF the blood isn’t being pumped out the heart properly so it pools in the heart. Anticoagulants can get in and sort this out, but anti platelets can’t!!!
Anticoagulants to consider: warfarin, the NOACs
In AF patients anticoagulated with warfarin (vitamin K antagonist) to reduce risk of stroke, what should we aim for their INR to be?
Between 2 and 3
We want to prevent stroke but we want to prevent them having a bleed so don’t want INR to be too high!!
Remember we saw in anticoagulation topic patients with INR between 1-2 are at increased risk of stroke
Over 3 and your increasing the risk of bleeds
Are the NOACs allowed in AF patients for prevention of stroke?
Yes!
Dabigatran, Rivaroxiban and Apixaban are all now licensed and recommended for stroke prevention in AF
We need to monitor renal function (don’t use with eGFRs below 30) And also caution with liver
Rivaroxiban is equally effective as warfarin for prevention of stroke
It’s a proven alternative to warfarin for moderate or high risk patients with AF
In atrial fibrillation where is the blood clot most likely to arise from (90%of cases)?
From the left atrial appendage (a pouch in the left atrium that doesn’t really have a function)
This is where the blood pools and clots most of the time in AF
The clotted blood can then be dislodged and pumped out (embolised) to the brain
How do we sort out the problem with blood pooling and clotting in the left atrial appendage of the heart?
This little pouch in the heart doesn’t really have a function, but it causes problems because it’s where blood likes to pool and collect in AF.
So we can actually seal off this pouch so that the blood doesn’t pool there any more. This is called LA appendage closure.
We use something called a WATCHMAN LEFT ATRIA CLOSURE DEVICE. Its like a little cup that we lodge in to close off the pouch to the rest of the heart, in OPEN HEART SURGERY
Once we’ve closed off the left ventricular appendage using a watchman device, what does this mean for the patient?
They are at reduced risk of stroke
The don’t have to take anticoagulants any more
Can heparin be used as a anti-thrombus agent in the acute treatment of stroke?
No- no benefit, just excess of cerebral and extra cerebral bleeds
Use alteplase (also known as rt-PA)
How can we tell if it’s TIA or stroke??
Patients with stroke symptoms tend to last longer. TIA come on all of a sudden and then recovery quite quickly.
But a CT scan will confirm it: a faint white line will indicate ischemia, a large white blob will indicate heamorrhage (both types of strokes)
Whys it so important to act as quickly as possible with strokes?
If you can get the clot busting drugs in ASAP there’s more chance of stopping complications associated with strokes
The best outcomes are when rt-PA is given within 3 hours of acute stroke!!
May prevent a patient spending the rest of their lives disabled
We stop giving thrombolysis after 4.5 hours as this does more bad than good
When a patient comes in to emergency department with stroke symptoms we do a CT scan to see if it’s heamorrhagic. We then assess whether we can give them rt-PA. We then scan again to assess bleeding. We then wait a further 24 hours to give antiplatelet drugs (aspirin). Aspirin should be given with 48 hours.
Why do we have to wait so long to give aspirin and why do we have to assess for bleeding?
When patients have a stroke their blood vessels are disrupted so it increases their risk of bleeding.
Anti platelets also increase risk of bleeding, so we have to ensure there is no active bleeding and there is less risk of a bleed before we give aspirin, so that’s why we wait and do a re-scan!!
Never give Alteplase and aspirin at the same time!!!
If we can’t give them alteplase because it’s been longer than 4.5 hours what do we do??
We wait 24 hours then give aspirin, as waiting this long will ensure the risk of bleeding caused by damage to the blood vessels from the stroke has gone.
The risk of stroke in men under 85 is higher than that of women under 85. Why?
The risk of stroke in the elderly is greater in women over 85 than men. Why?
Up to middle aged menopausal women are protected from stroke by their oestrogens!!
Women tend to live longer than men, therefore more women are living to over 85 and are getting strokes!
Rivaroxiban is equally effective as warfarin for prevention of stroke
It’s a proven alternative to warfarin for moderate or high risk patients with AF
In atrial fibrillation where is the blood clot most likely to arise from (90%of cases)?
From the left atrial appendage (a pouch in the left atrium that doesn’t really have a function)
This is where the blood pools and clots most of the time in AF
The clotted blood can then be dislodged and pumped out (embolised) to the brain
How do we sort out the problem with blood pooling an clotting in the left atrial appendage of the heart?
This little pouch in the heart doesn’t really have a function, but it causes problems because it’s where blood likes to pool and collect in AF.
So we can actually seal off this pouch so that the blood doesn’t pool there any more. This is called LA appendage closure.
We use something called a WATCHMAN LEFT ATRIA CLOSURE DEVICE. Its like a little cup that we lodge in to close off the pouch to the rest of the heart, in OPEN HEART SURGERY
Once we’ve closed off the left ventricular appendage using a watchman device, what does this mean for the patient?
They are at reduced risk of stroke
The don’t have to take anticoagulants any more
Can heparin be used as a anti-thrombus agent in the acute treatment of stroke?
No- no benefit, just excess of cerebral and extra cerebral bleeds
Use alteplase (also known as rt-PA)
If the CHA2DS2- VASc score comes out at 2 or over (or for men over 1), and the bleed risk has been assessed and is low, what OAC should we offer?
The different options of OAC should be discussed with the patient and the choice should be based on their clinical features and preference
Can aspirin as a monotherapy be offered solely for stroke prevention in people with AF??
No
Aspirin monotherapy should not be used for stroke prevention in AF patients, they need an anticoagulant
FOR PATIENTS WITH paroxysmal, persistent or permanent AF, What do stroke guidelines say about when anticoagulation should be started following a TIA and what kind of anticoagulation??
Anticoagulation should be commenced immediately following a TIA once brain imaging has ruled out a haemorrhage, using an agent with a rapid onset such as a LMWH or an oral direct thrombin inhibitor (Dabigatran) or a factor Xa inhibitor (Apixaban, Rivaroxiban).
NICE haven’t said this, however Helena said to follow stroke guidelines
FOR PATIENTS WITH paroxysmal, persistent or permanent AF, the stroke guidelines say that anticoagulation should not be given after stroke or TIA until brain imaging has excluded _______?
Excluded haemorrhage
FOR PATIENTS WITH paroxysmal, persistent or permanent AF, the stroke guidelines say that anticoagulation should not be commenced in patients with uncontrolled ________
Hypertension (systolic is persistently 160 or over)
FOR PATIENTS WITH paroxysmal, persistent or permanent AF, who have had a DISABLING ischeamic stroke, how long should we wait to give anticoagulation according to the stroke guidelines?
In patients who’ve had a disabling stroke, anticoagulation should be deferred until at least 14 days have passed since onset. (Aspirin 300mg daily should be used until then).
Follow these stroke guidelines!!
FOR PATIENTS WITH paroxysmal, persistent or permanent AF, who have had a NON-DISABLING ischeamic stroke, how long should we wait to give anticoagulation according to the stroke guidelines?
Should be deferred for an interval at the discretion of the prescriber (but no later than 14 days from onset)
Follow stroke guidelines!!
Only 50% of patients who would benefit from warfarin therapy for AF actually receive treatment. Why?
Some patients won’t be on warfarin because they don’t like it
Also because of the risk of bleeding
Also left atrial appendage conclusions devices (watchman device) are being used which rules out the need to anticoagulation.
Also due to the difficulties surrounding frequent INR testing and dose adjustments with warfarin. The NOACs are now starting to be used more and more in AF. But we need to make sure patients are aware that NOACs are better in their effectiveness, just because of less INR monitoring!!
What are the symptoms of AF??
Light headedness Palpitations Fatigue Shortness of breath (dyspnea) Syncope (loss of conciousness) Chest pain
What’s the difference between permanent, persistent and paroxysmal AF??
Permanent is long standing AF (over 1 year) - we need rate control with this kind
Persistent is non self- terminating AF (I.e. It lasts longer than 7 days) and requires rhythm control
Paroxysmal AF that spontaneously gets rid of itself within 7 days and usually within 48 hours. It also requires rhythm control. Need to identify trigger factors. These patients may benefit from pill in pocket to treat flare ups.
Why do we have to monitor TFT with AF?
TFT= thyroid function test
This is because AF may be caused by underlying thyroid disease
Paroxysmal AF can go on to become Persistent AF (lasts longer than 7 days) which can then go in to become permanent AF (long standing, lasts for over 1 year)
Anticoagulation is indicated for all 3 of these types of AF to prevent stroke occurring!!!
What is first line for treating (not new in onset) AF?
RATE control: monotherapy with a beta blocker or rate-limiting CCB
But not in patients with heart failure, new onset AF or AF with a cause such as an infection!!
What is second line in treating (not new in onset) AF??
Rate control dual therapy So any 2 of: Beta blocker Diltiazem (CCB) Digoxin
Monitor cardiac output if using beta blocker and diltiazem together (due to possible heart block)
Digoxin should only be used in sedentary patients
What is 3rd line for patient with (not new onset) AF?
Rhythm control
Can be either pharmacological cardioversion with:
Amiodarone,
Flecainide,
Soltalol
Or electrical cardioversion (non-pharmacological option)
What anticoagulants are used for the prevention of stroke and systemic embolism in non-valvular AF?
Warfarin
Dabigatran
Rivaroxiban
Apixaban
For patients on warfarin who have a labile INR, what should you consider?
Switching them to a NOAC - dabigatran
If aged over 75 then automatically allowed dabigatran
Or if over 65 and have diabetes
If we were switching from warfarin to dabigatran, how should this be done?
When warfarin is stopped, dabigatran can be started as soon as the INR is less than 2.0.
Renal function should be checked before starting a NOAC (and if elderly should be checked at least annually thereafter!!)
She should be monitored for signs of bleeding and anaemia
What’s the counselling with the NOACs??
Report any bleeding or bruising
They don’t require monitoring of INR
Ensure it is taken regularly
If a dose is missed, take missed dose as soon as possible unless within 6 hours of next dose being due.
What is furosemide used for?
Symptoms of heart failure (it’s a loop diuretic so used for oedema caused by HF)
We know that digoxin can be used as dual antiplatelet therapy in AF. It should only be used in certain cases however. What are these?
Sedentary patients.
For patients with a high ventricular rate.
Only in persistent of permanent AF (NOT in paroxysmal: this is where AF Comes and goes but digoxin will permanently slow the heart rate down: risk of it becoming too slow in patients with paroxysmal AF!!
Paroxysmal AF patients benefit more from pill in pocket so they can use it for flare ups)
NB: hyperkaleamia (high potassium) can cause digoxin toxicity!
Digoxin is also used in heart failure patients.
Patients on digoxin have increased mortality
Aspirin in AF…
NO EVIDENCE FOR ASPIRINS USE IN AF SO STOP THE ASPIRIN IN THESE PATIENTS!!
We know that Beta-blockers are used first and second line in patients with AF. What co-morbidity are these cautioned in??
Diabetes
As they can mask hypos!
Need to balance the benefits of beta blockers against this risk
What can AF be caused by and associated with ?
High blood pressure (main one) Coronary artery disease Mitral heart valve disease Congenital heart valve disease Thyroid gland disorders (monitor thyroid function tests) Pneumonia
Why does alcohol (drinking 8 or over alcoholic drinks a week) cause an increased risk of bleeding and therefore included in the HASBLED scoring system?
Alcohol causes risk of bleeding due to liver damage
What’s the purpose of rhythm control in AF?
To get them back into sinus rhythm
What do we need to monitor in AF??
Manual pulse checks
TFT (thyroid function tests to check thyroid disease isn’t underlying cause)
FBC- to check for aneamia
U&Es: for kidney function and to make sure they generally look okay
Blood pressure
BLood glucose: to rule out Hypoglyceamia
What’s first list for patients with non valvular AF??
Non valvular AF is the main cause of AF and it just means AF that is not caused by mitral heart disease or rhumatoid arthritis.
These patients should always be on a beta blocker and an anticoagulant (once CHADSVasc and HASBLED have been assessed)
If on a Statin for risk reductions in AF for stroke, which Statin is preferred?
Atrovastatin
And at a high dose- 80mg. Start at 20mg and titrate upwards
We should consider taking patients off this if they are over 90 because the Statin reduces 10 year risk: are they going to live for 10 years?
What’s the important thing to remember about CCBs used in AF patients??
They should be rate-limiting CCBs. Usually diltiazem. Normal CCBs would cause heart block with beta blockers
