Test bank for critical care nursing a holistic approach 11th edition morton f...
Cardioembolic Stroke - KEO VEASNA, MD
1. KEO VEASNA, MD
Cho Ray Phnom Penh Hospital
Medicine Department
ISCHEMIC STROKE
Cardioembolic Stroke
2. Outline :
Definition
Epidemiology
Classification ( Subtype, TOAST)
Cardiogenic stroke
Introduction
Diagnostic Approach to Suspected Cardioembolic Stroke
Differential diagnosis
Atrial fibrillation vs Stroke
When to start anticoagulant in Stoke/ A.Fib
3. “rapidly developing clinical signs of focal (or global)
disturbance of cerebral function, lasting more than
24 hours or leading to death, with no apparent cause
other than that of vascular origin [1].”
By this definition, TIA, which last <24h, and patient with stroke
symptoms cause by subdural hemorrhage, tumors, poisoning or trauma
are excluded.
1. WHO MONICA project Investigators. The World Health Organization MONICA Project (Monitoring trends and determinants in
Cardiovascular disease). J.Clin Epidemiol 41, 105-114.1988
WHO Definition of stoke :
10. Cardioembolic stroke
Cardioembolic stroke accounts for approximately 20% to 30% of
all ischemic strokes.
It can result from :
Ventricular thrombus
Structural heart defects
Aortic arch atheroma
Acute myocardial infraction
Valvular heart disease
Continuum (Minneap Minn) 2017;23(1):111–132
11. Diagnostic Approach to Suspected
Cardioembolic Stroke :
Detailed history and physical examination
ECG, laboratory studies
Echocardiography
Neuroimaging : CT scan / MRI
13. Laboratory Studies
Complete blood cell count
Blood cultures : Infective endocarditis
Erythrocyte sedimentation rate, C-reactive protein : Elevated
in infection, vasculitis, malignancy
Prothrombin time, partial thromboplastin time, international
normalized ratio : detect coagulopathies
Thyroid function tests
Lipid profile
Hypercoagulable panel : young patients with family history
suggestive of thrombophilia and no vascular risk factors
14. Imaging Studies
CT/MRI brain
CT: Widely available, fast, excludes intracerebral hemorrhage,
assists in determining eligibility for thrombolysis.
MRI: Useful for clinically evident and subclinical strokes,
vascular distributions, chronic infarcts; more sensitive for
detecting ischemia in the posterior fossa.
Vascular imaging : Doppler ultrasound, CTA, MRA
Chest x-ray
15. Cardiac Evaluation
Serial ECG
Cardiac telemetry
Extended cardiac monitoring
Many patients require Holter or event monitoring to detect
occult atrial fibrillation.
Transthoracic echocardiography (TTE) :
Noninvasive, evaluates heart structure and function, good
for left ventricular thrombus
Transesophageal echocardiography (TEE) :
Superior for evaluating the aortic arch, the left atrial appendage,
the aortic valve, and the atrial septum, but more invasive than
TTE
25. CT Early signs of ischemia :
Hypo attenuating brain tissue : Giảm đậm độ nhu mô
Obscuration of the lentiform nucleus : Xóa mờ nhân đậu
Insular Ribbon sign : Mờ rãnh Sylvius
Dense MCA sign
Lose of gray – white interface
26. 4 Early CT signs of infarction. (a) Hyperdense right middle cerebral artery, suggesting
intravascular occlusion by thromboembolism. (b) Loss of differentiation between gray and
white matter. The left lentiform nucleus is visible, as normal, as a slightly hyperdense
structure (single arrow), but is absent on the right (double arrow) because of edema from
infarction. (c) Large area of hypoattenuation (arrows)
27. Atrail Fibrillation vs Stroke :
The most common significant cardiac arrhythmia
A major risk factor for ischemic stroke
Is estimated to affect between 2.7 and 6.1 million Americans,
with an estimated 16 million people affected by the year 2050
Strokes from AF tend to be more severe, resulting in greater
disability and mortality.
approach to anticoagulation should be similar in patients with
paroxysmal AF and those with persistent/permanent AF
31. HAS - BLED
H : Hypertension 1
A : Abnormal renal and/orliver 1or2
function
S : Stroke history 1
B : Bleeding history 1
L : Labile international 1
normalized ratio
E : Elderly 1
D : Drugs or alcohol 1
38. Advantages and Disadvantages of Warfarin
Adavantages:
Warfarin
Once-daily dosing
Prothrombin time/international
normalized ratio used for
monitoring and widely available
Reversal agents widely available:
vitamin K, fresh frozen plasma,
prothrombin complex concentrate,
recombinant activated factor VIIa
Inexpensive
Longer half-life; better protection
in patients who are noncompliant
Safer than novel oral anticoagulants
in patients with significant renal
dysfunction
Disadavantages:
Dietary restrictions; need relatively
constant vitamin K intake
Requires frequent blood monitoring,
especially with initiation
Time in therapeutic range is
approximately 55Y66%
Many drug interactions
39. Advantages and Disadvantages Novel Oral
Anticoagulants
Advantages:
No dietary restrictions
Can be used in fixed doses; with
adjustments for age and renal
function
No need for routine blood monitoring
Wide therapeutic window with low
interindividual and intraindividual
variability
Idarucizumab reverses dabigatran;
hemodialysis and activated charcoal
can also be used to reverse
this agent
Less risk of intracerebral hemorrhage
than warfarin
Rapid onset of action
Disadvantages:
May require more frequent dosing
Expensive
Renal function affects pharmacokinetics
No specific reversal agent for factor Xa
inhibitors, although prothrombin complex
concentrate or plasma exchange may be
used for life-threatening bleeds
Because of short half-lives, strict
compliance is crucial; missing even one
dose results in diminished protection
CT has the advantage of being available 24 hours a day and is the gold standard for hemorrhage. Hemorrhage on MR images can be quite confusing. On CT 60% of infarcts are seen within 3-6 hrs and virtually all are seen in 24 hours. The overall sensitivity of CT to diagnose stroke is 64% and the specificity is 85%.
In the table on the left the early CT-signs of cerebral infarction are listed.
