Biomaterial Database

Incidence of transcranial Doppler-detected cerebral microemboli in patients referred for echocardiography. 1994

D C Tong, and A Bolger, and G W Albers

Department of Neurology and Neurological Sciences, Stanford University Medical Center, Palo Alto, CA.

OBJECTIVE Transcranial Doppler can detect cerebral microemboli. These emboli may be a risk factor for embolic stroke. We studied the prevalence of microemboli in patients referred for echocardiography. METHODS Forty-two patients were evaluated. Patients were studied with continuous monitoring over one middle cerebral artery for 30 minutes, and the number of microemboli was recorded. Patients were divided into three groups, those with prosthetic heart valves (group A, n = 15), atrial fibrillation (group B, n = 14), and no major cardiac risk factor (group C, n = 14). RESULTS Seventeen percent (7 of 42) of all patients had microemboli. In group A, 5 of 15 (33%) had microemboli. In group B, 2 of 13 (15%) patients had microemboli. Twenty-five percent (7 of 28) of patients in groups A and B combined (A+B) had microemboli. No patients (0 of 14) in group C had microemboli. Groups A and A+B had significantly more emboli than group C (P < .05). Prosthetic heart valve patients with emboli more commonly had a history of prior stroke than valve patients without emboli (3 of 5 versus 2 of 10). The number of emboli seen per 30-minute monitoring session was greater in patients with a prior history of stroke than in patients without (10 microemboli versus 3). CONCLUSIONS Microemboli can be found in a significant percentage of selected patients referred for echocardiography. The prevalence of microembolism is greater in patients with a known high risk of embolization (eg, prosthetic valves) and less in patients with a lower risk of embolization (eg, atrial fibrillation). These microemboli may be associated with an increased prevalence of previous stroke in patients with prosthetic valves.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D012017	Referral and Consultation	The practice of sending a patient to another program or practitioner for services or advice which the referring source is not prepared to provide.	Consultation,Gatekeepers, Health Service,Hospital Referral,Second Opinion,Consultation and Referral,Health Service Gatekeepers,Hospital Referrals,Referral,Referral, Hospital,Referrals, Hospital,Consultations,Gatekeeper, Health Service,Health Service Gatekeeper,Opinion, Second,Opinions, Second,Referrals,Second Opinions
D002339	Carotid Arteries	Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.	Arteries, Carotid,Artery, Carotid,Carotid Artery
D002542	Intracranial Embolism and Thrombosis	Embolism or thrombosis involving blood vessels which supply intracranial structures. Emboli may originate from extracranial or intracranial sources. Thrombosis may occur in arterial or venous structures.	Brain Embolism and Thrombosis,Cerebral Embolism and Thrombosis,Embolism and Thrombosis, Brain
D002546	Ischemic Attack, Transient	Brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. Events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (From Adams et al., Principles of Neurology, 6th ed, pp814-6)	Brain Stem Ischemia, Transient,Cerebral Ischemia, Transient,Crescendo Transient Ischemic Attacks,Transient Ischemic Attack,Anterior Circulation Transient Ischemic Attack,Brain Stem Transient Ischemic Attack,Brain TIA,Brainstem Ischemia, Transient,Brainstem Transient Ischemic Attack,Carotid Circulation Transient Ischemic Attack,Posterior Circulation Transient Ischemic Attack,TIA (Transient Ischemic Attack),Transient Ischemic Attack, Anterior Circulation,Transient Ischemic Attack, Brain Stem,Transient Ischemic Attack, Brainstem,Transient Ischemic Attack, Carotid Circulation,Transient Ischemic Attack, Posterior Circulation,Transient Ischemic Attack, Vertebrobasilar Circulation,Transient Ischemic Attacks, Crescendo,Vertebrobasilar Circulation Transient Ischemic Attack,Attack, Transient Ischemic,Attacks, Transient Ischemic,Brainstem Ischemias, Transient,Cerebral Ischemias, Transient,Ischemia, Transient Brainstem,Ischemia, Transient Cerebral,Ischemias, Transient Brainstem,Ischemias, Transient Cerebral,Ischemic Attacks, Transient,TIA, Brain,TIAs (Transient Ischemic Attack),Transient Brainstem Ischemia,Transient Cerebral Ischemia,Transient Cerebral Ischemias,Transient Ischemic Attacks
D002561	Cerebrovascular Disorders	A spectrum of pathological conditions of impaired blood flow in the brain. They can involve vessels (ARTERIES or VEINS) in the CEREBRUM, the CEREBELLUM, and the BRAIN STEM. Major categories include INTRACRANIAL ARTERIOVENOUS MALFORMATIONS; BRAIN ISCHEMIA; CEREBRAL HEMORRHAGE; and others.	Brain Vascular Disorders,Intracranial Vascular Disorders,Vascular Diseases, Intracranial,Cerebrovascular Diseases,Cerebrovascular Insufficiency,Cerebrovascular Occlusion,Brain Vascular Disorder,Cerebrovascular Disease,Cerebrovascular Disorder,Cerebrovascular Insufficiencies,Cerebrovascular Occlusions,Disease, Cerebrovascular,Diseases, Cerebrovascular,Insufficiencies, Cerebrovascular,Insufficiency, Cerebrovascular,Intracranial Vascular Disease,Intracranial Vascular Diseases,Intracranial Vascular Disorder,Occlusion, Cerebrovascular,Occlusions, Cerebrovascular,Vascular Disease, Intracranial,Vascular Disorder, Brain,Vascular Disorder, Intracranial,Vascular Disorders, Brain,Vascular Disorders, Intracranial
D004452	Echocardiography	Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.	Echocardiography, Contrast,Echocardiography, Cross-Sectional,Echocardiography, M-Mode,Echocardiography, Transthoracic,Echocardiography, Two-Dimensional,Transthoracic Echocardiography,2-D Echocardiography,2D Echocardiography,Contrast Echocardiography,Cross-Sectional Echocardiography,Echocardiography, 2-D,Echocardiography, 2D,M-Mode Echocardiography,Two-Dimensional Echocardiography,2 D Echocardiography,Cross Sectional Echocardiography,Echocardiography, 2 D,Echocardiography, Cross Sectional,Echocardiography, M Mode,Echocardiography, Two Dimensional,M Mode Echocardiography,Two Dimensional Echocardiography
D006350	Heart Valve Prosthesis	A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.	Prosthesis, Heart Valve,Cardiac Valve Prosthesis,Cardiac Valve Prostheses,Heart Valve Prostheses,Prostheses, Cardiac Valve,Prostheses, Heart Valve,Prosthesis, Cardiac Valve,Valve Prostheses, Cardiac,Valve Prostheses, Heart,Valve Prosthesis, Cardiac,Valve Prosthesis, Heart