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Costa M, Schmitt P, N J, Baldoncini M, Vivanco-Suarez J, Chaurasia B, Douville C, Yince L, Patel A, Monteith S. Transcranial Doppler emboli monitoring for stroke prevention after flow diverting stents. J Cerebrovasc Endovasc Neurosurg 2024; 26:23-29. [PMID: 37813698 PMCID: PMC10995465 DOI: 10.7461/jcen.2023.e2023.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/07/2023] [Accepted: 07/07/2023] [Indexed: 10/11/2023] Open
Abstract
OBJECTIVE Flow diverting stents (FDS) are increasingly used for the treatment of intracranial aneurysms. While FDS can provide flow diversion of parent vessels, their high metal surface coverage can cause thromboembolism. Transcranial Doppler (TCD) emboli monitoring can be used to identify subclinical embolic phenomena after neurovascular procedures. Limited data exists regarding the use of TCDs for emboli monitoring in the periprocedural period after FDS placement. We evaluated the rate of positive TCDs microembolic signals and stroke after FDS deployment at our institution. METHODS We retrospectively evaluated 105 patients who underwent FDS treatment between 2012 and 2016 using the Pipeline stent (Medtronic, Minneapolis, MN, USA). Patients were pretreated with aspirin and clopidogrel. All patients were therapeutic on clopidogrel pre-operatively. TCD emboli monitoring was performed immediately after the procedure. Microembolic signals (mES) were classified as "positive" (<15 mES/hour) and "strongly positive" (>15 mES/hour). Clinical stroke rates were determined at 2-week and 6-month post-operatively. RESULTS A total of 132 intracranial aneurysms were treated in 105 patients. TCD emboli monitoring was "positive" in 11.4% (n=12) post-operatively and "strongly positive" in 4.8% (n=5). These positive cases were treated with heparin drips or modification of the antiplatelet regimen, and TCDs were repeated. Following medical management modifications, normalization of mES was achieved in 92% of cases. The overall stroke rates at 2-week and 6-months were 3.8% and 4.8%, respectively. CONCLUSIONS TCD emboli monitoring may help early in the identification of thromboembolic events after flow diversion stenting. This allows for modification of medical therapy and, potentially, preventionf of escalation into post-operative strokes.
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Affiliation(s)
- Matias Costa
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
| | - Paul Schmitt
- Department of Neurosurgery, University of Texas Medical Branch, Texas, USA
| | - Jaleel N
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
- Division of Neurosurgery, Dartmouth-Hitchcock Medical Center, New Hampshire, USA
| | - Matias Baldoncini
- Department of Neurological Surgery, Hospital San Fernando, Buenos Aaires, Argentina
| | - Juan Vivanco-Suarez
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
| | - Bipin Chaurasia
- Department of Neurosurgery, Neurosurgery Clinic, Birgunj, Nepal
| | - Colleen Douville
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
| | - Loh Yince
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
| | - Akshal Patel
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
| | - Stephen Monteith
- Department of Neurosurgery, Swedish Neuroscience Institute, Seattle, Washington, USA
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Ravenberg KK, Gabriel MM, Leotescu A, Tran AT, Grosse GM, Schuppner R, Ernst J, Lichtinghagen R, Tiede A, Werwitzke S, Bara CL, Schmitto JD, Weissenborn K, Hanke JS, Worthmann H. Microembolic signal monitoring in patients with HeartMate 3 and HeartWare left ventricular assist devices: Association with antithrombotic treatment and cerebrovascular events. Artif Organs 2023; 47:370-379. [PMID: 36114791 DOI: 10.1111/aor.14409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/07/2022] [Accepted: 09/06/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND In patients with left ventricular assist devices (LVADs), ischemic and hemorrhagic stroke are dreaded complications. Predictive markers for these events are lacking. This study aimed to investigate the prevalence and predictive value of microembolic signals (MES) for stroke, detected by Transcranial Doppler sonography (TCD) in patients with HeartMate 3 (HM 3) or HeartWare (HW). METHODS A thirty-minute bilateral TCD monitoring of the middle cerebral artery (MCA) was performed in 62 outpatients with LVAD (HM 3 N = 31, HW N = 31) and 31 healthy controls. Prevalence and quantity of MES were investigated regarding clinical and laboratory parameters. Cerebrovascular events (CVE) were recorded on follow-up at 90 and 180 days. RESULTS MES were detected in six patients with HM 3, three patients with HW, and three controls. Within the LVAD groups, patients on monotherapy with vitamin-K-antagonist (VKA) without antiplatelet therapy were at risk for a higher count of MES (negative binomial regression: VKA: 1; VKA + ASA: Exp(B) = 0.005, 95%CI 0.001-0.044; VKA + clopidogrel: Exp(B) = 0.012, 95%CI 0.002-0.056). There was no association between the presence of MES and CVE or death on follow-up (p > 0.05). CONCLUSION For the first time, the prevalence of MES was prospectively investigated in a notable outpatient cohort of patients with HM 3 and HW. Despite optimized properties of the latest LVAD, MES remain detectable depending on antithrombotic therapy. No association between MES and CVE could be detected.
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Affiliation(s)
| | | | - Andrei Leotescu
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Anh Thu Tran
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | | | - Ramona Schuppner
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Johanna Ernst
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Ralf Lichtinghagen
- Institute of Clinical Chemistry, Hannover Medical School, Hannover, Germany
| | - Andreas Tiede
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Sonja Werwitzke
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Christoph Leon Bara
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Jan Dieter Schmitto
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | | | - Jasmin Sarah Hanke
- Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Hans Worthmann
- Department of Neurology, Hannover Medical School, Hannover, Germany
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Weil EL, Noseworthy PA, Lopez CL, Rabinstein AA, Friedman PA, Attia ZI, Yao X, Siontis KC, Kremers WK, Christopoulos G, Mielke MM, Vemuri P, Jack CR, Gersh BJ, Machulda MM, Knopman DS, Petersen RC, Graff-Radford J. Artificial Intelligence-Enabled Electrocardiogram for Atrial Fibrillation Identifies Cognitive Decline Risk and Cerebral Infarcts. Mayo Clin Proc 2022; 97:871-880. [PMID: 35512882 PMCID: PMC9179015 DOI: 10.1016/j.mayocp.2022.01.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/01/2021] [Accepted: 01/11/2022] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To investigate whether artificial intelligence-enabled electrocardiogram (AI-ECG) assessment of atrial fibrillation (AF) risk predicts cognitive decline and cerebral infarcts. PATIENTS AND METHODS This population-based study included sinus-rhythm ECG participants seen from November 29, 2004 through July 13, 2020, and a subset with brain magnetic resonance imaging (MRI) (October 10, 2011, through November 2, 2017). The AI-ECG score of AF risk calculated for participants was 0-1. To determine the AI-ECG-AF relationship with baseline cognitive dysfunction, we compared linear mixed-effects models with global and domain-specific cognitive z-scores from longitudinal neuropsychological assessments. The AI-ECG-AF score was logit transformed and modeled with cubic splines. For the brain-MRI subset, logistic regression evaluated correlation of the AI-ECG-AF score and the high-threshold, dichotomized AI-ECG-AF score with infarcts. RESULTS Participants (N=3729; median age, 74.1 years) underwent cognitive analysis. Adjusting for age, sex, education, and APOE ɛ4-carrier status, the AI-ECG-AF score correlated with lower baseline and faster decline in global-cognitive z-scores (P=.009 and P=.01, respectively, non-linear-based spline-models tests) and attention z-scores (P<.001 and P=.01, respectively). Sinus-rhythm-ECG participants (n=1373) underwent MRI. As a continuous measure, the AI-ECG-AF score correlated with infarcts but not after age and sex adjustment (P=.52). For dichotomized analysis, an AI-ECG-AF score greater than 0.5 correlated with infarcts (OR, 4.61; 95% CI, 2.45-8.55; P<.001); even after age and sex adjustment (OR, 2.09; 95% CI, 1.06-4.07; P=.03). CONCLUSION The AI-ECG-AF score correlated with worse baseline cognition and gradual global cognition and attention decline. High AF probability by AI-ECG-AF score correlated with MRI cerebral infarcts. However, most infarcts observed in our cohort were subcortical, suggesting that AI-ECG not only predicts AF but also detects other non-AF cardiac disease markers and correlates with small vessel cerebrovascular disease and cognitive decline.
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Affiliation(s)
- Erika L Weil
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | - Camden L Lopez
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA
| | | | - Paul A Friedman
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Zachi I Attia
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Xiaoxi Yao
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA; Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, MN, USA
| | | | - Walter K Kremers
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA
| | | | - Michelle M Mielke
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA
| | | | | | - Bernard J Gersh
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Mary M Machulda
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
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Huang G, Johnson LL, Peacock JE, Tegeler C, Davis K, Sarwal A. Transcranial Doppler Emboli Monitoring for Infective Endocarditis. J Neuroimaging 2020; 30:486-492. [PMID: 32488942 DOI: 10.1111/jon.12721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Ischemic stroke can occur in 20-55% of patients with infective endocarditis (IE) with 75% occurring during the first 2 weeks of treatment. CT or MRI brain can diagnose the sequelae of stroke but transcranial Doppler (TCD) can document active embolization. We undertook a retrospective review of our patient cohort and a systematic review of literature to assess the role of TCD in early diagnosis and management of ischemic stroke in IE. METHODS Retrospective chart review and literature review. RESULTS We found 89 patients with stroke caused by IE at our institution from December 2011 to April 2018. TCDs were obtained on 26 patients; 16 were abnormal for cerebrovascular abnormalities. Only 4 patients had 30-minute emboli monitoring performed, of which one revealed emboli. We found 3 studies investigating the role of TCDs in IE that showed promise in its use as a predictive tool in stroke risk stratification. CONCLUSIONS Presence of embolization in the form of high-intensity transient signals (HITS) detected on TCDs can be used for early diagnosis of IE, assessing efficacy of antibiotic therapy, and stratification of stroke risk in IE. This can aid further research into testing preventative interventions for reducing stroke burden in IE such as earlier valvular surgery or vacuum-assisted vegetation extraction.
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Affiliation(s)
- Glen Huang
- Department of Internal Medicine, University of California Los Angeles, Los Angeles, CA
| | - Leilani L Johnson
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - James E Peacock
- Department of Internal Medicine, Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - Charles Tegeler
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - Kyle Davis
- Department of Pharmacy, Wake Forest Baptist Medical Center, Winston-Salem, NC
| | - Aarti Sarwal
- Department of Neurology, Wake Forest Baptist Medical Center, Winston-Salem, NC
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Cerebral Microembolization in Left Ventricular Assist Device Associated Ischemic Events. J Stroke Cerebrovasc Dis 2020; 29:104660. [PMID: 32044219 DOI: 10.1016/j.jstrokecerebrovasdis.2020.104660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION The significance of microembolic signals (MES) detected by transcranial Doppler ultrasound emboli monitoring (TCD-e) in patients supported with left ventricular assist devices (LVAD) remains unclear. We aimed to investigate the relationship between cerebral microembolization detected by TCD-e and acute ischemic events in LVAD patients. METHODS We reviewed consecutive patients with acute ischemic stroke or transient ischemic attack (TIA) in a prospectively collected database of LVAD patients. TCD-e exams consisted of monitoring the middle cerebral arteries for microembolic signals (MES) over 30 minutes. RESULTS Of 515 persons with LVAD, 41 TCD-e studies were performed in 35 patients with acute ischemic stroke or transient ischemic attack (TIA) in a median of 1 day (Interquartile range [IQR]: 0-2) after the event. MES were present in 15 (44%) TCD-e studies with a median MES count of 4 (IQR: 2-15.5). Bloodstream infections were more common in patients with MES (38% versus 8%, P = .039). There were trends for lower international normalized ratio (1.39 versus 1.69, P = .214), lower activated partial thromboplastin (33.2 versus 36.6, P = .577), higher lactate dehydrogenase (531 versus 409, P = .323) and a higher frequency of pump thrombosis (13% versus 8%, P = .637) in patients with MES compared with those without MES. CONCLUSIONS LVAD patients with acute ischemic stroke or TIA have a high prevalence of MES on TCD-e, which may serve as a marker for a prothrombotic state. Further study of MES in LVAD patients is warranted.
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Abstract
Atrial fibrillation (AF) is the most common arrhythmia in adults, and its incidence and prevalence increase with age. The risk of cognitive impairment and dementia also increases with age, and both AF and cognitive impairment or dementia share important risk factors. In meta-analyses of published studies, AF is associated with a 2.4-fold and 1.4-fold increase in the risk of dementia in patients with or without a history of stroke, respectively. This association is independent of shared risk factors such as hypertension and diabetes mellitus. Neuroimaging has illustrated several potential mechanisms of cognitive decline in patients with AF. AF is associated with increased prevalence of silent cerebral infarcts, and more recent data also suggest an increased prevalence of cerebral microbleeds with AF. AF is also associated with a pro-inflammatory state, and the relationship between AF-induced systemic inflammation and dementia remains to be investigated. Preliminary reports indicate that anticoagulation medication including warfarin can reduce the risk of cognitive impairment in patients with AF. Catheter ablation, increasingly used to maintain sinus rhythm in patients with AF, is associated with the formation of new silent cerebral lesions. The majority of these lesions are not detectable after 1 year, and insufficient data are available to evaluate their effect on cognition. Large prospective studies are urgently needed to confirm the association between AF and dementia, to elucidate the associated mechanisms, and to investigate the effect of anticoagulation and rhythm control on cognition.
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Kargiotis O, Psychogios K, Safouris A, Magoufis G, Zervas PD, Stamboulis E, Tsivgoulis G. The Role of Transcranial Doppler Monitoring in Patients with Multi‐Territory Acute Embolic Strokes: A Review. J Neuroimaging 2019; 29:309-322. [DOI: 10.1111/jon.12602] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/21/2019] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Affiliation(s)
| | | | - Apostolos Safouris
- Stroke UnitMetropolitan Hospital Piraeus Greece
- Second Department of NeurologyNational & Kapodistiran University of Athens, School of Medicine, “Attikon” University Hospital Athens Greece
| | | | - Paschalis D. Zervas
- Second Department of NeurologyNational & Kapodistiran University of Athens, School of Medicine, “Attikon” University Hospital Athens Greece
| | | | - Georgios Tsivgoulis
- Second Department of NeurologyNational & Kapodistiran University of Athens, School of Medicine, “Attikon” University Hospital Athens Greece
- Department of NeurologyThe University of Tennessee Health Science Center Memphis TN
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8
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The Clinical Implication of Transcranial Doppler Detection of Microembolic Signals in Patients with Heartmate II. ASAIO J 2018; 64:694-696. [DOI: 10.1097/mat.0000000000000702] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Tan S, Zhang L, Chen X, Wang Y, Lin Y, Cai W, Shan Y, Qiu W, Hu X, Lu Z. Comparison of the Chinese ischemic stroke subclassification and Trial of Org 10172 in acute stroke treatment systems in minor stroke. BMC Neurol 2016; 16:162. [PMID: 27601009 PMCID: PMC5011990 DOI: 10.1186/s12883-016-0688-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/29/2016] [Indexed: 11/25/2022] Open
Abstract
Background The underlying causes of minor stroke are difficult to assess. Here, we evaluate the reliability of the Chinese Ischemic Stroke Subclassification (CISS) system in patients with minor stroke, and compare it to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) system. Methods A total of 320 patients with minor stroke were retrospectively registered and categorized into different subgroups of the CISS and TOAST by two neurologists. Inter- and intra-rater agreement with the two systems were assessed with kappa statistics. Results The percentage of undetermined etiology (UE) cases in the CISS system was 77.3 % less than that in the TOAST system, which was statistically significant (P < 0.001). The percentage of large artery atherosclerosis (LAA) in the CISS system was 79.7 % more than that in the TOAST system, which was also statistically significant (P < 0.001). The kappa values for inter-examiner agreement were 0.898 (P = 0.031) and 0.732 (P = 0.022) for the CISS and TOAST systems, respectively. The intra-observer reliability indexes were moderate (0.569 for neurologist A, and 0.487 for neurologist B). Conclusions The CISS and TOAST systems are both reliable in classifying patients with minor stroke. CISS classified more patients into known etiologic categories without sacrificing reliability.
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Affiliation(s)
- Sha Tan
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Lei Zhang
- Department of Neurology, The Fifth Affiliated Hospital of Sun Yat-sen University, No 52 Meihuadong Road, Zhuhai City, China
| | - Xiaoyu Chen
- Department of Neurology, People's Hospital of Zhongshan City, No 2 Sun Yat-sen East Road, Zhongshan City, China
| | - Yanqiang Wang
- Department of Neurology, Affiliated Hospital of Weifang Medical University, No 465 Yuhe Road, Weifang City, China
| | - Yinyao Lin
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Wei Cai
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Yilong Shan
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Wei Qiu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Xueqiang Hu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China
| | - Zhengqi Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, Guangdong, China.
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Graff-Radford J, Madhavan M, Vemuri P, Rabinstein AA, Cha RH, Mielke MM, Kantarci K, Lowe V, Senjem ML, Gunter JL, Knopman DS, Petersen RC, Jack CR, Roberts RO. Atrial fibrillation, cognitive impairment, and neuroimaging. Alzheimers Dement 2015; 12:391-8. [PMID: 26607820 DOI: 10.1016/j.jalz.2015.08.164] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 08/13/2015] [Accepted: 08/27/2015] [Indexed: 01/10/2023]
Abstract
INTRODUCTION The objective of our study was to investigate cross-sectional associations of atrial fibrillation with neuroimaging measures of cerebrovascular disease and Alzheimer's disease and their interactions with mild cognitive impairment (MCI). METHODS Magnetic resonance imaging scans of individuals from a population-based study were analyzed for infarctions, total gray matter, and hippocampal and white matter hyperintensity volumes. A subsample underwent positron emission tomography imaging. RESULTS Atrial fibrillation was associated with infarctions and lower total gray matter volume. Compared with subjects with no atrial fibrillation and no infarction, the odds ratio (95% confidence intervals) for MCI was 2.99 (1.57-5.70; P = .001) among participants with atrial fibrillation and infarction, 0.90 (0.45-1.80; P = .77) for atrial fibrillation and no infarction, and 1.50 (0.96-2.34; P = .08) for no atrial fibrillation and any infarction. DISCUSSION Participants with both atrial fibrillation and infarction are more likely to have MCI than participants with either infarction or atrial fibrillation alone.
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Affiliation(s)
| | - Malini Madhavan
- Department of Cardiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Prashanthi Vemuri
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | | | - Ruth H Cha
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Michelle M Mielke
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA; Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Kejal Kantarci
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Val Lowe
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Matthew L Senjem
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Jeffrey L Gunter
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - David S Knopman
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Ronald C Petersen
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Clifford R Jack
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Rosebud O Roberts
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA; Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, MN, USA.
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Ozaki CK, Sobieszczyk PS, Ho KJ, McPhee JT, Gravereaux EC. Evidence-based carotid artery-based interventions for stroke risk reduction. Curr Probl Surg 2014; 51:198-242. [PMID: 24767101 DOI: 10.1067/j.cpsurg.2014.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/29/2014] [Indexed: 11/22/2022]
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Boulon C, Baud JM, Kercret G, Pichot O, Poggi JN, Saby JC, Sprynger M. [Detection of micro-embolic signals: a review of the literature]. JOURNAL DES MALADIES VASCULAIRES 2012; 37:311-319. [PMID: 23146344 DOI: 10.1016/j.jmv.2012.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/28/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND The detection of micro-embolic signals (MES), by transcranial Doppler sonography might be useful for risk stratification in patients with symptomatic and asymptomatic carotid or cerebral artery stenosis, dissections, aortic atheroma, interventional procedures, and right to left cardiac shunts. AIM Review of the technique and clinical situations of MES detection. METHODS PubMed search from 1990 to 2012. RESULTS MES were found in 0,19, 48% versus 0,3, and 12% of patients with symptomatic and asymptomatic inferior than 30, 30 to 69, and 70 to 99% carotid stenosis, respectively. MES were related to the risk of recurrent stroke or transient ischemic attack (TIA). In the ACES study, the absolute annual risk of stroke or TIA after 2 years was 7% with vs 3% without MES. In patients with intracranial stenosis, the risk of stroke recurrence was 48% with vs 7% without MES at 13.6 months follow-up. MES were reported in 25% of the symptomatic versus none of the asymptomatic patients with intracranial stenosis. CONCLUSION Detection of MES is feasible and reproducible for multicenter studies, using rigourous methodology and long lasting recordings. It may contribute to risk stratification, especially in patients with extra- or intracranial stenosis.
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Affiliation(s)
- C Boulon
- Service de Médecine Vasculaire, Hôpital St-André, 1, rue Jean-Burguet, 33075 Bordeaux, France.
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Jayasooriya G, Thapar A, Shalhoub J, Davies AH. Silent cerebral events in asymptomatic carotid stenosis. J Vasc Surg 2011; 54:227-36. [PMID: 21722830 DOI: 10.1016/j.jvs.2011.01.037] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 01/12/2011] [Accepted: 01/17/2011] [Indexed: 01/20/2023]
Abstract
BACKGROUND Approximately 20% of strokes are attributable to carotid stenosis. However, the number of asymptomatic patients needed to prevent one stroke or death with endarterectomy is high at 17 to 32. There is a clear need to identify asymptomatic individuals at high risk of developing future ischemic events to improve the cost-effectiveness of surgery. Our aim was to examine the evidence for subclinical microembolization and silent brain infarction in the prediction of stroke in asymptomatic carotid stenosis using transcranial Doppler (TCD), computed tomography (CT), and magnetic resonance imaging (MRI). METHODS The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Articles regarding humans between 1966 and 2010 were identified through systematic searches of Pubmed, MEDLINE, and EMBASE electronic databases using a predetermined search algorithm. RESULTS Fifty-eight full text articles met the inclusion criteria. A median of 28% of microemboli positive patients experienced a stroke or transient ischemic attack during follow-up compared with 2% of microemboli negative patients (P = .001). The same was true for the end point of stroke alone with a median of 10% of microemboli positive patients experiencing a stroke vs 1% of microemboli negative patients (P = .004). A specific pattern of silent CT infarctions was related to future stroke risk (odds ratio [OR] = 4.6; confidence interval [CI] = 3.0-7.2; P < .0001). There are no prospective MRI studies linking silent infarction and stroke risk. CONCLUSIONS There is level 1 evidence for the use of TCD to detect microembolization as a risk stratification tool. However, this technique requires further investigation as a stroke prevention tool and would be complemented by improvements in carotid plaque imaging.
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Affiliation(s)
- Gayani Jayasooriya
- Academic Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
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Srivastava P. Optimization of antiplatelet/antithrombotic therapy for secondary stroke prevention. Ann Indian Acad Neurol 2011; 13:6-13. [PMID: 20436740 PMCID: PMC2859581 DOI: 10.4103/0972-2327.61270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 07/30/2009] [Accepted: 11/14/2009] [Indexed: 11/04/2022] Open
Abstract
Role of antiplatelet therapy in secondary stroke prevention is of major significance. Antiplatelet agents predominantly in use are aspirin, clopidogrel, and combination regimes. The review focuses on the optimization of antiplatelet regimen based on evidence obtained from randomized-controlled trials, on different antiplatelet regimes and the risk assessment that may be unique to each patient.
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Affiliation(s)
- Padma Srivastava
- Department of Neurology, CN Center, AIIMS, Ansari Nagar, New Delhi, India
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Risk Factors for Small Cortical Infarction on Diffusion-Weighted Magnetic Resonance Imaging in Patients With Acute Ischemic Stroke. J Stroke Cerebrovasc Dis 2011; 20:68-74. [DOI: 10.1016/j.jstrokecerebrovasdis.2009.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 10/07/2009] [Accepted: 11/07/2009] [Indexed: 11/20/2022] Open
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Potential relevance of low-intensity microembolic signals by TCD monitoring. Neurol Sci 2010; 32:107-11. [DOI: 10.1007/s10072-010-0429-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 09/10/2010] [Indexed: 11/30/2022]
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Telman G, Mesica O, Kouperberg E, Cohen O, Bolotin G, Agmon Y. Microemboli monitoring by trans-cranial doppler in patient with acute cardioemboliogenic stroke due to atrial myxoma. Neurol Int 2010; 2:e5. [PMID: 21577341 PMCID: PMC3093209 DOI: 10.4081/ni.2010.e5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 12/09/2009] [Accepted: 01/20/2010] [Indexed: 11/22/2022] Open
Abstract
This is the first reported attempt to examine the emboliogenic potential of cardiac myxoma in patients with acute stroke through the monitoring of microembolic signals (MES) by transcranial doppler. A 43-year old woman was brought to the emergency department because of acute onset of generalized tonic-clonic seizures and left hemiplegia. A CT scan of the brain demonstrated a large acute infraction in the territory of the right middle cerebral artery (MCA) and another smaller one in the territory of the posterior cerebral artery on the same side. Trans-cranial doppler (TCD) microemboli monitoring did not reveal MES. Transesophagial echocardiography (TEE) identified a 5 cm left atrial mass, which was highly suspected to be an atrial myxoma attached to the interatrial septum and prolapsed through the mitral valve. After the TEE results were obtained, another TCD monitoring was performed. Again, there were no MES found in either of the MCAs.Our findings showed the absence of MES on two consecutive TCD examinations, suggesting a spontaneous occurrence, rather than the permanent presence, of embolization, even in the most acute phase of stroke. Thus, the tendency of myxomas to spontaneously produce multiple emboli emphasizes the need for the surgical excision of myxomas.
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Lepur D, Barsić B. Incidence of neurological complications in patients with native-valve infective endocarditis and cerebral microembolism: an open cohort study. ACTA ACUST UNITED AC 2010; 41:708-13. [PMID: 19685379 DOI: 10.1080/00365540903146995] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The objective of this open cohort study was to assess the association between neurological complications in patients with definite native-valve infective endocarditis (IE) and cerebral microembolism (MES). MES detection was performed with 1-h, bilateral middle cerebral arteries (MCA) insonation using a transcranial Doppler ultrasound (TCD) machine. Thirty patients with definite native-valve IE were stratified into 2 groups based upon the presence of MES. The most striking difference between the 2 groups of patients was the incidence of clinically evident neurological complications. Neurological complications of IE occurred in 10 (83.3%) patients with positive MES and in 6 (33.3%) MES-negative patients (p=0.021). Ischaemic stroke was the most common complication, occurring in 11 of 16 patients, followed by meningitis in 4 patients and cerebritis in 1 patient. There was a trend towards greater in-hospital mortality in patients with recorded MES than in the MES-negative, although this was not statistically significant (33.3% vs 16.6%; p=0.392). Our results reveal a significant association between MES and neurological complications in patients with native-valve IE. TCD is a promising tool in predicting individual patient risk for neurological complications of IE.
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Affiliation(s)
- Dragan Lepur
- Department of Neuroinfections and Intensive Care Medicine, University Hospital for Infectious Diseases Dr. Fran Mihaljević, Zagreb, Croatia.
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Romano JG, Rabinstein AA, Arheart KL, Nathan S, Campo-Bustillo I, Koch S, Forteza AM. Microemboli in Aneurysmal Subarachnoid Hemorrhage. J Neuroimaging 2008; 18:396-401. [DOI: 10.1111/j.1552-6569.2007.00215.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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20
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Knecht S, Oelschläger C, Duning T, Lohmann H, Albers J, Stehling C, Heindel W, Breithardt G, Berger K, Ringelstein EB, Kirchhof P, Wersching H. Atrial fibrillation in stroke-free patients is associated with memory impairment and hippocampal atrophy. Eur Heart J 2008; 29:2125-32. [PMID: 18667399 DOI: 10.1093/eurheartj/ehn341] [Citation(s) in RCA: 222] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stefan Knecht
- Department of Neurology, University of Münster, A. Schweitzer Street 33, 48129 Münster, Germany.
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Ritter MA, Dittrich R, Thoenissen N, Ringelstein EB, Nabavi DG. Prevalence and prognostic impact of microembolic signals in arterial sources of embolism. J Neurol 2008; 255:953-61. [PMID: 18458865 DOI: 10.1007/s00415-008-0638-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 04/06/2007] [Accepted: 04/30/2007] [Indexed: 11/27/2022]
Affiliation(s)
- Martin A Ritter
- Dept. of Neurology, University of Münster, Albert-Schweitzer-Str. 33, 48129 Münster, Germany.
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22
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Zuromskis T, Wetterholm R, Lindqvist J, Svedlund S, Sixt C, Jatuzis D, Obelieniene D, Caidahl K, Volkmann R. Prevalence of Micro-Emboli in Symptomatic High Grade Carotid Artery Disease: A Transcranial Doppler Study. Eur J Vasc Endovasc Surg 2008; 35:534-40. [DOI: 10.1016/j.ejvs.2008.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 01/04/2008] [Indexed: 10/22/2022]
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Purandare N, Voshaar RCO, Morris J, Byrne JE, Wren J, Heller RF, McCollum CN, Burns A. Asymptomatic spontaneous cerebral emboli predict cognitive and functional decline in dementia. Biol Psychiatry 2007; 62:339-44. [PMID: 17531959 DOI: 10.1016/j.biopsych.2006.12.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 12/15/2006] [Accepted: 12/17/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Spontaneous cerebral emboli (SCE) are frequent in Alzheimer's disease (AD) and vascular dementia (VaD). We investigated the effect of SCE on the rates of cognitive and functional decline in AD and VaD. METHODS One hundred thirty-two patients with dementia (74 AD, National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association [NINCDS/ADRDA] criteria; 58 VaD, National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences [NINDS/AIREN] criteria) underwent 1-hour transcranial Doppler for detection of SCE (mean [SD] age 75.5 (7.4) years; 46% female). Neuropsychological tests (Mini-Mental State Examination [MMSE], Alzheimer's Disease Assessment Scale-Cognitive subscale [ADAS-Cog], and Neuropsychiatric Inventory [NPI]) and assessment of activities of daily living (Interview for Deterioration in Daily Living Activities in Dementia [IDDD]) were performed initially and 6 months later. SCE positive (SCE+ve, n = 47) and SCE negative (SCE-ve, n = 85) patients were compared using repeated measures analyses of variance (ANOVAs) adjusted for age, gender, and cardiovascular risk factors. RESULTS SCE+ve patients with dementia, both AD and VaD, suffered a more rapid decline in cognitive functioning over 6 months (ADAS-cog, mean increase 7.1 for SCE+ve compared with 3.3 for SCE-ve, p = .006) and activities of daily living (IDDD, mean increase 24.4 for SCE+ve compared with 10.8 for SCE-ve, p = .014). CONCLUSIONS Asymptomatic SCE are associated with an accelerated cognitive and functional decline in dementia. SCE may be a potentially treatable cause of disease progression in dementia.
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Affiliation(s)
- Nitin Purandare
- Division of Psychiatry, University of Manchester, Manchester, UK.
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Voshaar RCO, Purandare N, Hardicre J, McCollum C, Burns A. Asymptomatic spontaneous cerebral emboli and cognitive decline in a cohort of older people: a prospective study. Int J Geriatr Psychiatry 2007; 22:794-800. [PMID: 17192026 DOI: 10.1002/gps.1744] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Asymptomatic spontaneous cerebral emboli (SCE) are common in dementia and are associated with cognitive decline in dementia. The significance of their presence in older people is unknown. METHOD We included 96 participants (mean (SD) age 76.8 (6.7) years, 46% female) who were the control group in a case-control study to evaluate SCE in dementia. Cognitive functioning was assessed prospectively over 2.5 years, using the MMSE and CAMCOG. RESULTS The mean (SD) MMSE score was 28.7 (1.4) at baseline with an average (SD) drop of 0.79 (0.91) per year. The presence of SCE was not related to the annual drop in MMSE score, nor to the CAMCOG score at follow-up (p = 0.88 and p = 0.41, respectively). Linear regression analyses identified higher age in years (beta = 0.29, p = 0.003), history of stroke (beta = 0.31, p = 0.001) and carotid stenosis (beta = 0.28, p = 0.003) as independent predictors of cognitive decline. CONCLUSION We found no association between the presence of SCE and subsequent cognitive decline in older people without dementia.
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Affiliation(s)
- Richard C Oude Voshaar
- University of Manchester, Division of Psychiatry, Education and Research Centre, South Manchester University Hospital, Wythenshawe, Manchester, UK
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25
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Azarpazhooh MR, Chambers BR. Clinical application of transcranial Doppler monitoring for embolic signals. J Clin Neurosci 2006; 13:799-810. [PMID: 16908159 DOI: 10.1016/j.jocn.2005.12.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 12/20/2005] [Indexed: 12/12/2022]
Abstract
A major advantage of transcranial ultrasound is its suitability for continuous monitoring. Microembolic signals (MES) are brief, high-intensity transients that occur when particulate microemboli or gaseous microbubbles pass through the ultrasound beam. These MES have been detected in several clinical scenarios, but rarely in age-matched controls. The detection of MES provides important pathophysiological information in a variety of disorders, but their clinical importance and possible therapeutic implications are still under debate. The present article summarizes the significance of MES in different clinical settings and outlines some of the problems to be resolved so that transcranial ultrasound can be applied in clinical practice.
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Affiliation(s)
- M R Azarpazhooh
- National Stroke Research Institute, University of Melbourne, Austin Health, Heidelberg Heights, Victoria, Australia
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26
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Kilicaslan F, Verma A, Saad E, Rossillo A, Davis DA, Prasad SK, Wazni O, Marrouche NF, Raber LN, Cummings JE, Beheiry S, Hao S, Burkhardt JD, Saliba W, Schweikert RA, Martin DO, Natale A. Transcranial Doppler Detection of Microembolic Signals During Pulmonary Vein Antrum Isolation: Implications for Titration of Radiofrequency Energy. J Cardiovasc Electrophysiol 2006; 17:495-501. [PMID: 16684021 DOI: 10.1111/j.1540-8167.2006.00451.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cerebrovascular events are an important complication during pulmonary vein antrum isolation (PVAI). Microembolic signals (MES) have been associated with stroke and neurological impairment. However, the incidence of MES during PVAI, and their relationship to microbubble formation and radiofrequency (RF) parameters are unknown. OBJECTIVES We sought to assess the relationship between MES, microbubble detection, and neurological outcome and the impact of RF titration strategy on these parameters. METHODS We studied 202 patients in two groups undergoing PVAI using an intracardiac echocardiography (ICE)-guided technique. MES were detected by transcranial Doppler (TCD) using insonation of the middle cerebral arteries. The number of microbubbles on ICE were qualitatively labeled as FEW, MODERATE, and SHOWER. In group I (n = 107), RF output was titrated to avoid microbubble formation and in group II (n = 95), standard power-limited RF output was used. RESULTS TCD detected MES in all 202 patients during PVAI with an average of 1,793 +/- 547 per patient; 90% were detected during left atrial ablation. Over 85% of MES occurred after microbubbles. Group I patients had significantly lower numbers of MES (1,015 +/- 438 per patient) compared to group II patients (2,250 +/- 864 per patient) (P < 0.05). Group II also had a 3.1% incidence of acute neurological complications versus 0.9% in group I (P = 0.10). Patients with clinical events had significantly higher numbers of MES. There were no significant correlations between RF power, temperature, or impedence and MES number. CONCLUSIONS MES directly correlate to the amount of microbubble formation on ICE, and may result in cerebroembolic complications. Titration of RF according to microbubble formation by ICE during PVAI may be important for minimizing the occurrence of MES and possibly acute neurological complications.
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Affiliation(s)
- Fethi Kilicaslan
- Cleveland Clinic Foundation, Section of Pacing and Electrophysiology, Department of Cardiology, Cleveland, Ohio 44195, USA
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Caplan LR, Wong KS, Gao S, Hennerici MG. Is Hypoperfusion an Important Cause of Strokes? If So, How? Cerebrovasc Dis 2006; 21:145-53. [PMID: 16401883 DOI: 10.1159/000090791] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Accepted: 09/13/2005] [Indexed: 01/13/2023] Open
Abstract
Traditionally hypoperfusion and embolism are considered separate important causes of stroke in patients with arterial occlusive disease. However, although hypoperfusion and embolism differ in mechanisms and location, they generally coincide in severe obstructive lesions and cause washout disturbances of embolism in low perfusion territories distal to stenosis. Unless the collateral blood supply is sufficient to prevent ischemia, multiple remote spot-like infarctions occur within the hypoperfused brain territory. In border-zone distributed infarction - long suspected to result from hemodynamic compromise alone - complementary interaction of embolisation and hypoperfusion territories has to be considered. Thus hypoperfusion with embolism or embolism alone are the most common explanations for stroke, the former often associated with less severe clinical deficits than the latter.
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Affiliation(s)
- Louis R Caplan
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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Kudo T, Inoue Y, Nakamura H, Hirokawa M, Sugano N, Iwai T. Detection of peripheral microemboli through collateral circulation by Doppler ultrasound monitoring-report of 2 cases. Vasc Endovascular Surg 2005; 39:103-8. [PMID: 15696253 DOI: 10.1177/153857440503900110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is possible for a proximal arterial source to lead to distal atheroembolism even in the presence of chronic occlusive disease. However, no monitoring technique has been established regarding detection of peripheral emboli through the collateral circulation in the lower limbs. We report a 60-year-old woman and a 73-year-old man with iliac stenosis and complete occlusion of the ipsilateral superficial femoral artery in whom Doppler ultrasound successfully detected microembolic signals (MES) at the tibioperoneal trunk during percutaneous transluminal angioplasty (PTA) and stent placement. By means of continuous Doppler ultrasound monitoring, 29 MES were successfully detected immediately after PTA or stent placement (MESp) and 64 MES were detected immediately after the contrast medium administration (MESc). MESc generated significantly higher intensities (median 28, range 7 to 38) as opposed to MESp (median 21, range 5 to 35, p = 0.017). In addition, the intensity of MES after prestent PTA (n = 8, 25 dB, 12-35 dB) and stenting (n = 18, 22 dB, 9-35 dB) was significantly higher than that of MES after poststent PTA (n = 3, 13 dB, range; 5-16 dB), respectively (p = 0.041, p = 0.034). Iliac PTA and stent placement were successful. Ankle/brachial pressure index and the symptoms improved in both patients, who showed no embolic symptoms after the procedure. This study suggested that it was possible to detect peripheral microemboli through the collateral circulation by Doppler ultrasound monitoring and that this technique would be helpful to investigate the mechanism of embolization in patients with PTA and stent placement.
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Affiliation(s)
- Toshifumi Kudo
- Department of Vascular and Applied Surgery, Tokyo Medical and Dental University, Graduate School, Tokyo, Japan.
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Dittrich R, Ritter MA, Droste DW. Microembolus detection by transcranial doppler sonography. EUROPEAN JOURNAL OF ULTRASOUND : OFFICIAL JOURNAL OF THE EUROPEAN FEDERATION OF SOCIETIES FOR ULTRASOUND IN MEDICINE AND BIOLOGY 2002; 16:21-30. [PMID: 12470847 DOI: 10.1016/s0929-8266(02)00046-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Microembolic signals can be detected by transcranial ultrasound as signals of high intensity and short duration. These signals represent circulating gaseous or solid particles. To optimize the differentiation from artefacts and the background signal and to facilitate the clinical use, several attempts have been made to automatize the detection of microemboli. Microemboli occur spontaneously in various clinical situations but their clinical impact and possible therapeutical implications are still under debate. This article provides a review of the actual literature concerning the current state of technical and clinical aspects of microembolus detection.
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Affiliation(s)
- Ralf Dittrich
- Klinik und Poliklinik für Neurologie, Universitätsklinikum Münster, Albert-Schweitzer-Str 33, D-48129, Münster, Germany.
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Kudo T, Inoue Y, Sugano N, Iwai T. Doppler ultrasound monitoring for detection of microembolic signals in peripheral arteries. Eur J Vasc Endovasc Surg 2002; 24:37-42. [PMID: 12127846 DOI: 10.1053/ejvs.2002.1681] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE to use Doppler ultrasound to detect peripheral microemboluation. METHODS standard Transcranial Doppler equipment was used to peripheral detect peripheral embolic high intensity transient signals (HITSs) in a pig model following injection of microparticles and atheroma, and in 23 patients who underwent open repair of an abdominal aortic aneurysm (AAA), six patients with blue toe syndrome and 10 age matched healthy subjects. RESULTS the pig study showed increasing signal intensity with particle size. Particles of 100 (n=24), 200 (n=17), and 400 microm (n=31) elicited 14, 25, 33 dB signals, respectively (p<0.05). During AAA surgery, the intensity (median) of HITSs before clamping (n=226) and after declamping (n=1216) were 14, and 20dB, respectively (p<0.001). Quite a few HITSs were detected after surgery. In patients with blue toe syndrome, a total of 63 HITSs could be detected, and the frequency of HITSs (median: 5.72/30min) was significantly higher than that in patients with AAA before surgery (0.065/30min) (p<0.001). CONCLUSIONS Doppler ultrasound technique may be a clinically useful test to guide the treatment of patients at risk of distal atheroembolic events.
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Affiliation(s)
- T Kudo
- Department of Surgery, Division of Vascular Surgery, Tokyo Medical and Dental University, School of Medicine, Tokyo, Japan
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Baumgartner RW, Frick A, Kremer C, Oechslin E, Russi E, Turina J, Georgiadis D. Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic heart valves. J Thorac Cardiovasc Surg 2001; 122:1142-6. [PMID: 11726888 DOI: 10.1067/mtc.2001.117282] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Patients with prosthetic heart valves have an increased risk of thromboembolic events, and transcranial Doppler sonography reveals microembolic signals. Whereas microembolic signals were initially assumed to be of particulate matter, recent studies suggest that they are partially gaseous in origin. If this is true, alteration of environmental pressure should change microembolic signal counts. We undertook this study to evaluate the influence of hyperbaric exposure on microembolic signal counts in persons with prosthetic heart valves. METHODS AND RESULTS Microembolic signal counts were monitored by transcranial Doppler sonography of both middle cerebral arteries under normobaria (normobaria 1), 2 subsequent periods of hyperbaria (2.5 and 1.75 bar), and a second period of normobaria (normobaria 2) in 15 patients with prosthetic heart valves. Each monitoring period lasted 30 minutes. Compression and decompression rates were 0.1 bar/min. Microembolic signal counts increased from 20 (12-78) at normobaria 1 to 79 (30-165) at 2.5 bar (P <.01 vs normobaria 1 and 2), decreased to 44 (18-128) at 1.75 bar (P <.01 vs normobaria 1 and 2.5 bar; P <.001 vs normobaria 2), and returned to 20 (8-96) at normobaria 2 (values are medians and 95% confidence intervals). CONCLUSIONS Our results strongly suggest that gaseous bubbles are underlying material for part of the microembolic signals detected in patients with prosthetic heart valves.
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Yasaka M, Yamaguchi T. Secondary prevention of stroke in patients with nonvalvular atrial fibrillation: optimal intensity of anticoagulation. CNS Drugs 2001; 15:623-31. [PMID: 11524034 DOI: 10.2165/00023210-200115080-00005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Nonvalvular atrial fibrillation (NVAF) is frequently seen in elderly people and has become a main cause of cardioembolic stroke. The efficacy of anticoagulation for primary prevention of stroke or transient ischaemic attacks (TIAs) in patients with NVAF has been established by prospective, randomised and controlled trials. Warfarin decreased the frequency of all strokes by 68% and the rate of the combined outcome of stroke, systemic embolism or death by 48%. Anticoagulation with warfarin using international normalised ratios (INRs) ranging from 2.0 to 3.0 is recommended for patients with NVAF, who have any of the risk factors identified by the Atrial Fibrillation Investigators (AFI) [previous stroke or TIA, history of hypertension, diabetes mellitus, advanced age (> or = 65 years old), congestive heart failure and coronary artery disease], the American College of Chest Physicians (ACCP) [increased age (> 75 years old), prior stroke, hypertension and heart failure], or the Stroke Prevention in Atrial Fibrillation (SPAF) investigators [women > 75 years old, prior stroke, systolic blood pressure > 160mm Hg, recent heart failure, and fractional shortening < 25% on echocardiography]. For the secondary prevention of stroke, the efficacy of adjusted-dose warfarin therapy has been demonstrated by 2 major randomised trials. SPAF III (INR 2.0 to 3.0) demonstrated a lower incidence of ischaemic stroke or systemic embolism (3.4 %/year) compared with low fixed-dose warfarin plus aspirin (acetylsalicylic acid) [11.9%]. The European Atrial Fibrillation Trial [EAFT] (INR 2.5 to 4.0) showed a lower incidence of all stroke (4.0 %/year) with adjusted-dose warfarin compared with placebo (12.0 %/year). The incidence of major bleeding in the adjusted-dose warfarin group in SPAF III and EAFT was 2.4 and 2.8 %/year, respectively. EAFT incidence rates for the occurrence of a first ischaemic or haemorrhagic complication analysed by INR range indicated that the rate was lowest at INRs of 2.0 to 2.9, and higher with INRs of 3.0 to 3.9. Therefore, the optimal intensity of anticoagulation for prevention of recurrent stroke seems to be an INR of between 2.0 and 3.0, as for primary prevention. Retrospective and prospective studies from Japan reported that in the elderly, haemorrhagic complications occur frequently with INRs above 2.6 and major ischaemic events cannot be prevented at INRs below 1.6. Therefore, an INR target between 1.6 and 2.6 may be an alternative for secondary prevention of stroke in elderly patients with NVAF who have a potential risk of bleeding, to avoid both major ischaemic and haemorrhagic events. Antiplatelets may be administered in patients who are unable to manage taking warfarin properly or who have a high risk of falling and subsequently sustaining a head injury, although the efficacy of antiplatelets for secondary prevention of stroke in NVAF has not yet been established.
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Affiliation(s)
- M Yasaka
- Cerebrovascular Division, Department of Medicine, National Cardiovascular Center, Osaka, Japan.
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Koch S, Romano JG, Bustillo IC, Concha M, Forteza AM. Anticoagulation and microembolus detection in a case of internal carotid artery dissection. J Neuroimaging 2001; 11:63-6. [PMID: 11198532 DOI: 10.1111/j.1552-6569.2001.tb00013.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Microembolic signals (MES) have been demonstrated by transcranial Doppler (TCD) in cases of internal carotid artery dissection. The influence of treatment on MES in arterial dissection is uncertain. The authors here present a case of internal carotid artery dissection in which we detected a reduction of MES after the initiation of intravenous heparin. METHODS A 37-year-old woman developed a right temporal headache 10 days prior to admission. This was followed by episodes of left arm numbness and weakness. Magnetic resonance imaging (MRI) showed a right frontal and deep subcortical ischemic infarct. Catheter angiography confirmed a right internal carotid artery dissection with intracranial extension. She was then monitored with TCD for MES before and after intravenous heparin was started. RESULTS The first TCD, performed 12 days after symptom onset, showed 39 MES during 60 minutes of insonation of the right middle cerebral artery. Treatment with intravenous heparin resulted in a decline in MES by 50% after 96 hours. This decline continued and no further MES were detected after 11 days of anticoagulation. CONCLUSION The authors were able to demonstrate a decline of MES with heparin anticoagulation in a case of internal carotid artery dissection.
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Tegos TJ, Sabetai MM, Nicolaides AN, Robless P, Kalodiki E, Elatrozy TS, Ramaswami G, Dhanjil S. Correlates of embolic events detected by means of transcranial Doppler in patients with carotid atheroma. J Vasc Surg 2001; 33:131-8. [PMID: 11137933 DOI: 10.1067/mva.2001.109746] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE This study identified in patients with carotid plaques the associations of emboli detected by means of transcranial Doppler (TCD) with cerebrovascular symptoms, brain computed tomography (CT) infarction patterns, and the attributes of plaques (echodensity, degree of stenosis). METHODS Eighty carotid plaques (in 59 patients), producing 50% to 99% stenosis, were imaged on duplex scanning and analyzed echomorphologically in a computer with the gray scale median (GSM). The GSM facilitated the quantitative distinction of dark (low GSM) from bright (high GSM) plaques. Stenosis was assessed with duplex scanning. Emboli were counted on TCD in the ipsilateral middle cerebral artery for half an hour. The brain CT infarction patterns (pattern A: discrete subcortical and cortical; pattern B: hemodynamic, diffuse white matter lesions, basal ganglia infarctions, lacunes) and normal CT and cerebrovascular symptoms on the ipsilateral hemisphere were noted. RESULTS Emboli were more frequent in symptomatic (median count, 3) than asymptomatic (median count, 0) hemispheres (Mann-Whitney U test, P =.031) and in hemispheres with pattern A infarction (median count, 3.5) than in hemispheres with pattern B infarction or normal CT (median count, 0; Kruskal-Wallis test, P =.047). The increased embolic count was associated with decreased GSM (Spearman correlation, P =.045, r = -0.22), but not with high degrees of stenosis (Spearman correlation, P =.44, r = 0.086). CONCLUSION Emboli were more frequent in symptomatic than asymptomatic hemispheres and in CT pattern A harboring hemispheres than in CT pattern B or normal hemispheres. They were more frequent in the presence of low-plaque echodensity, but not in the presence of a high degree of stenosis. These data support the embolic nature of cerebrovascular symptomatology and CT pattern A infarctions.
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Affiliation(s)
- T J Tegos
- Irvine Laboratory for Cardiovascular Investigation and Research, Department of Vascular Surgery, St Mary's Hospital, Imperial College of Science, Technology, and Medicine, London, UK.
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Tegos TJ, Kalodiki E, Sabetai MM, Nicolaides AN. Stroke: pathogenesis, investigations, and prognosis--Part II of III. Angiology 2000; 51:885-94. [PMID: 11103857 DOI: 10.1177/000331970005101101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part I the epidemiology, clinical picture, and risk factors were discussed, while part III will consist of the management and rehabilitation). In the present part (II) the pathogenetic and pathophysiologic aspects of stroke are described. Regarding the investigations apart from the history and clinical examination and general investigations, the following specialized investigations and their role are discussed in detail: Computed tomography (CT), magnetic resonance imaging (MRI), xenon-blood-flow, positron emission tomography (PET), cerebral angiography, magnetic resonance angiography (MRA), ultrasonography, transcranial Doppler (TCD), echocardiography, Holter monitoring, and biopsies. In addition, taking into account the information from the above-cited modalities a prognosis for the final outcome is presented.
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Affiliation(s)
- T J Tegos
- Department of Vascular Surgery, St. Mary's Hospital, Imperial College of Science, Technology and Medicine, London, England.
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Abstract
Transcranial Doppler ultrasound allows noninvasive monitoring of the large intracranial vessels. Microembolic signals (MES) have been observed under a variety of circumstances, especially in symptomatic carotid stenosis, high-risk cardiac conditions, and surgical procedures (such as carotid endarterectomy and cardiopulmonary bypass surgery). Technical considerations have presented numerous challenges to the interpretation of these signals, many of which appear to represent small emboli traveling in the blood flow. The technical aspects of these MES are discussed and their significance in relation to cerebral ischemia and its prevention are examined in some detail.
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Affiliation(s)
- M Gorman
- Department of Neurology, Wayne State University, Detroit, MI, USA.
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Kay R, Chung HK, Wong KS, Li H, Wong A, Woo KS, Sanderson J. Transcranial Doppler evaluation of microembolism immediately after direct-current cardioversion for atrial fibrillation in anticoagulated patients. Am J Cardiol 1999; 84:937-8, A7. [PMID: 10532517 DOI: 10.1016/s0002-9149(99)00472-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Transcranial Doppler monitoring showed no evidence of microemboli for 10 minutes after direct-current cardioversion for atrial fibrillation.
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Affiliation(s)
- R Kay
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, China.
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Mess WH, Titulaer BM, Ackerstaff RG. Middle cerebral artery anatomy and characteristics of embolic signals: a dual gate computer simulation study. ULTRASOUND IN MEDICINE & BIOLOGY 1999; 25:531-539. [PMID: 10386728 DOI: 10.1016/s0301-5629(99)00005-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In terms of microembolic signal (MES) detection, the anatomy of the middle cerebral artery (MCA) mainstem has only scarcely been considered. The vessel itself, however, could be at least partly responsible for the enormous variation when calculating the essential time difference (deltat) values of MES using the dual-gate technique. Therefore, we studied the time characteristics of MES in a computer simulation applying an anatomically realistic vessel and a dual-gate TCD approach. Three different MCA anatomies and two MES to blood intensities were simulated as well as two different sample volume settings. The MES length (proximal sample volume t1; distal sample volume t2) and deltat were calculated for different angles of insonation and sample volume depths. The calculations of the time characteristics of MES showed extreme variation, with only modest changes of the insonation angle (t1 4-34 ms; deltat 9-27 ms) or the sample volume depth (t1 7-27 ms; deltat 6-32 ms). The variation could be considerably reduced with modified TCD settings i.e., a shorter gate separation combined with a shorter receiver gate time in the distal sample volume (deltat with changing insonation angles 6-19 ms; deltat with changing insonation depths 13-17 ms). These results not only urge us to a cautious interpretation of the properties of single MES, but also contribute to an understanding of the marked deltat variation using the dual-gate technique.
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Affiliation(s)
- W H Mess
- St. Antonius Hospital, Dept. of Clinical Neurophysiology, Nieuwegein, The Netherlands.
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Al-Hamali S, Baskerville P, Fraser S, Walters H, Markus HS. Detection of distal emboli in patients with peripheral arterial stenosis before and after iliac angioplasty: a prospective study. J Vasc Surg 1999; 29:345-51. [PMID: 9950992 DOI: 10.1016/s0741-5214(99)70387-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Embolism is believed to be the major cause of end-organ damage after angioplasty and endoluminal procedures. Recently, Doppler ultrasound scanning has been used to detect asymptomatic cerebral emboli. We determined whether asymptomatic embolic signals (ES) could be detected distal to a significant iliac artery stenosis of >60% both before and soon after iliac percutaneous transluminal angioplasty (PTA). METHODS A 2-MHz Doppler scan probe was used to monitor for ES in the common femoral artery before and after 10 successful iliac artery PTAs and at various standardized times in the following 24 hours. The same protocol was used to study 10 patients in the control group after renal PTA. In addition, a single recording was performed in a second nonoperative control group of 10 patients who had no evidence of peripheral vascular disease. The Doppler scan signals were recorded on tape for a later blinded analysis. RESULTS In the 24 hours before iliac PTA, asymptomatic ES were detected in four of 10 patients during a 1-hour recording but in no controls (P =.025). After iliac PTA, ES were detected at 30 minutes in nine of 10 iliac subjects but in only one of 10 renal subjects (P =.0003) and at 2 hours in eight of 10 iliac subjects but in only one of 10 renal subjects (P =.001). The occurrence of ES became less frequent, and ES were present at a lower frequency in eight of 10 iliac PTA subjects at 4 hours and in five of 10 at 24 hours but in no renal PTA subjects at these time points. CONCLUSIONS ES can be detected in the common femoral artery with Doppler ultrasound scanning in patients with iliac artery stenosis both before and soon after iliac PTA despite preangioplasty aspirin and intra-angioplasty heparin therapies. The occurrences of ES were particularly frequent in the 2 hours after PTA. This technique can be used further to study factors that control plaque stability and to evaluate the effect of therapeutic interventions.
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Affiliation(s)
- S Al-Hamali
- Department of Clinical Neuroscience, King's College School of Medicine, United Kingdom
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