Introduction
Prevalence of cardiac abnormalities in stroke patients
Cardiac imaging after ischemic stroke
Echocardiography
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Echocardiography is feasible and safe in patients with (acute) ischemic stroke or TIA.**
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TTE and TOE have to be considered as complimentary methods that provide distinct aspects of cardiac pathologies.**
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TOE is the method of choice for refined imaging of the atria and the interatrial septum. Details of (peri-)valvular abnormalities can be diagnosed with higher accuracy.**
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TTE is able to assess global and regional wall motion, ventricular abnormalities and left atrial function.**
TTE | TOE | CT | MRI | |
---|---|---|---|---|
Availability | Widely available (bedside) | Widely available (fasting required) | Widely available | Limited capacities |
Invasiveness | Non-invasive | Semi-invasive | Radiation exposure | Non-invasive |
Resolution | Good spatial & excellent temporal resolution (potentially impaired by patient’s characteristics) | Excellent spatial & temporal resolution | Excellent spatial resolution & good temporal resolutiona | Good spatial resolution & excellent tissue characterization |
Costs | Comparatively cheap | Moderate | Comparatively expensive | Comparatively expensive |
Operator dependence | High | High | Low | Low |
Level of required patient cooperation | Comparatively low | Comparatively high (may require sedation) | Comparatively low | Comparatively high |
Duration | Fast acquisition | Longer acquisition time | Fast acquisition | Longer acquisition time |
Contrast agent | (Echocardiographic contrast agent) | (Echocardiographic contrast agent) | Iodinated contrast agent | Gadolinium exposure |
Structures/Pathologies | ||||
Left ventricular | ||||
Dysfunction | + + + | + + | + | + + + |
Thrombus | + + | + | + + | + + + |
Cardiomyopathies | + + + | + | + | + + + |
Coronary artery disease b | + + | + | + + + | + + |
Left atrial | ||||
Morphology | + + | + + + | + + + | + + |
Dysfunction | + + + | + + | + | + + |
Thrombus | + + | + + + | + + + | + + |
Left atrial appendix | ||||
Morphology | + | + + + | + + + | + |
Dysfunction | + | + + + | + | + |
Thrombus | + | + + + | + + + | + + |
Interatrial septal defects | + + | + + + | + | + |
Intracardiac shunt | + + | + + | + | + + |
Endocarditis | + + | + + + | + + + c | + |
(Peri-)valvular disease | + + | + + + | + + + | + + |
Valvular calcifications | + + | + + | + + + | + + |
Cardiac tumors | + + | + + | + + + | + + + |
Thoracic aorta | ||||
Morphology | + | + + | + + + | + + |
Plaques | + | + + | + + + | + + |
Dissection | + | + + + | + + + | + + |
Cardiac computed tomography
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Cardiac CT is feasible in stroke patients due to the short acquisition time; however, it comes at the cost of radiation exposure.*
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Cardiac CT can be a complementary imaging method for additional work-up of specific patients with acute ischemic stroke or TIA, but is not optimal for the evaluation of most frequent cardiac sources of embolism.*
Cardiac MRI
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Cardiac MRI is a complementary imaging method for work-up of specific cardiac pathologies, for example tumors, cardiomyopathies and left ventricular thrombi or prior myocardial infarction.**
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Cardiac MRI is not optimal for the evaluation of PFO or the detection of endocarditis.
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In general, cardiac MRI requires comparatively long image acquisition times and affords the patient to follow commands, limiting the feasibility in acute stroke patients.*
Left atrial imaging in stroke patients
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Left atrial imaging may be used to assess atrial cardiomyopathy.*
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Presence of atrial cardiomyopathy can help to tailor the intensity of post-stroke monitoring for AF.**
Practical recommendations to use cardiac imaging after ischemic stroke or TIA
Setting for echocardiography
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A standardized set-up and experienced investigators are needed for echocardiographic examinations in stroke patients, which should follow a systematic, standardized protocol.*
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An interdisciplinary team and standard operating procedures for post-stroke cardiac imaging may enhance decision making and advise further work-up including special cases where cardiac CT or MRI are required.*
Patient selection
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Stroke or TIA patients should undergo cardiac imaging, if stroke etiology is uncertain.*
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Stroke or TIA patients should undergo cardiac imaging, if the presence of pathological findings would alter (medical) management.*
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Cardiac imaging should be considered in ischemic stroke patients with at least one established cardiovascular risk factor to identify cardiac comorbidities, unless cardiologic work-up within the last 6 months is documented in stroke patients without signs of cardiac dysfunction.
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Stroke or TIA patients with AF should undergo cardiac imaging for further cardiac work-up, if the presence of a left-sided atrial or ventricular thrombus would alter (medical) management or if a first episode of AF was documented in-hospital.*
Imaging method of choice
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Echocardiography is the gold standard imaging modality after ischemic stroke or TIA, if a pathological finding would alter (medical) management.*
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TOE and TTE should be performed (preferably in a single session) if a cardio-embolic source is deemed a probable cause of ischemic stroke or TIA.
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TTE should be performed in patients with suspicious findings during TOE, if TOE alone is not sufficient for the comprehensive evaluation of the specific pathology (e.g. regional wall motion abnormalities or apical left ventricular thrombus).
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TOE should be performed in patients with suspicious findings during TTE, if TTE alone is not sufficient for the comprehensive evaluation of the specific pathology (e.g. endocarditis or assessment of (inter)atrial structures).**
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TOE should be performed (in patients with so far cryptogenic stroke aged 16–60 years), if PFO presence would alter further management.*
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TTE should be performed in stroke patients with a first episode of AF in-hospital.*
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TTE should be considered in ischemic stroke patients with at least one established cardiovascular risk factor unless recent cardiologic work-up is documented.*
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Cardiac CT should be considered, if there is a suspicion of cardiac or extra cardiac abnormalities, based on other imaging modalities, which are assumed to be clinically relevant. As cardiac CT is associated with radiation exposure, use of cardiac CT should be based on an individual decision.*
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Cardiac MRI should be considered, if there is a suspicion of left ventricular thrombus or cardiac tumor or in case of an unclear cardiomyopathy after contrast enhanced echocardiography.
Incidental imaging findings
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Diagnostic algorithms and interdisciplinary standard operating procedures should be established to avoid over-diagnosis and “over-treatment” because of incidental findings of cardiac imaging.*
Cost-effectiveness of cardiac imaging after stroke
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Cost-effectiveness of systematic cardiac imaging in stroke patients should be addressed in prospective trials.
Imaging of the aortic arch
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A CT angiography scan can visualize the whole aortic arch and the descending aorta whereas TOE often is impaired by suboptimal acoustic properties of the aortic arch.
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MRI angiography can depict aortic pathology but acquisition is time-consuming, more expensive, and limited with regard to calcifications, mobile structures and ulcerations.*