Selection of patients for transesophageal echocardiography after stroke and systemic embolic events. Role of transthoracic echocardiography

Multimodal Cardiac Imaging in the Assessment of Patients Who Have Suffered a Cardioembolic Stroke: A Review

Cardioembolic strokes account for 20-25% of all ischaemic strokes, with their incidence increasing with age. Cardiac imaging plays a crucial role in identifying cardioembolic causes of stroke, with early and accurate identification affecting treatment, preventing recurrence, and reducing stroke incidence. Echocardiography serves as the mainstay of cardiac evaluation. Transthoracic echocardiography (TTE) is the first line in the basic evaluation of structural heart disorders, valvular disease, vegetations, and intraventricular thrombus. It can be used to measure chamber size and systolic/diastolic function. Trans-oesophageal echocardiography (TOE) yields better results in identifying potential cardioembolic sources of stroke and should be strongly considered, especially if TTE does not yield adequate results. Cardiac computed tomography and cardiac magnetic resonance imaging provide better soft tissue characterisation, high-grade anatomical information, spatial and temporal visualisation, and image reconstruction in multiple planes, especially with contrast. These techniques are useful in cases of inconclusive echocardiograms and can be used to detect and characterise valvular lesions, thrombi, fibrosis, cardiomyopathies, and aortic plaques. Nuclear imaging is not routinely used, but it can be used to assess left-ventricular perfusion, function, and dimensions and may be useful in cases of infective endocarditis. Its use should be considered on a case-by-case basis. The accuracy of each imaging modality depends on the likely source of cardioembolism, and the choice of imaging approach should be tailored to individual patients.

Clinical Utility of the Transthoracic Echocardiogram for Isolated Lacunar Infarcts: A Single-Center Experience

BACKGROUND

Stroke is a prominent and financially burdensome disease. Lacunar strokes are traditionally attributed to small vessel disease rather than cardioemboli, which typically occlude larger arteries. Thus, the benefit of screening for potential sources of cardioemboli in lacunar stroke patients is unclear. We evaluated the clinical utility of the transthoracic echocardiogram performed in patients with lacunar strokes.

METHODS

A single-center retrospective analysis of ischemic stroke patients from January 2013 through December 2017 was performed. Brain magnetic resonance imaging was used to select patients with a single lacunar infarct. Patients presenting with acute symptoms of cardiac disease or an abnormal electrocardiogram were excluded. Transthoracic echocardiogram results were reviewed, and their utility in decision-making was evaluated.

RESULTS

Of the 442 patients at our institution diagnosed with ischemic stroke during the inclusion period, 89 met inclusion criteria. Transthoracic echocardiogram detected a patent foramen ovale in 5.6% of patients, mitral annular calcification in 9.0% of patients, and abnormal wall motion in 4.5% of patients. For all patients, there were no findings that prompted anticoagulation, antibiotic, or surgical intervention. The cost of an inpatient transthoracic echocardiogram is $4100, resulting in $364,900 in unnecessary health care spending.

CONCLUSIONS

Transthoracic echocardiogram appears to have minimal therapeutic value in most patients with lacunar strokes. In stroke patients with no acute symptoms of cardiac disease and a normal electrocardiogram, it may be reasonable to forgo the transthoracic echocardiogram if the brain magnetic resonance imaging shows an isolated lacunar infarct.

Prevalence of left atrial appendage thrombus in patients with acute ischaemic stroke and sinus rhythm: a cross-sectional study

OBJECTIVE

Thrombi originating in the left atrial appendage (LAA) mainly form because of atrial fibrillation (AF) and are a known cause of cardioembolic stroke. We aimed to investigate the prevalence of LAA thrombus in patients with acute ischaemic stroke (AIS) and sinus rhythm on 12-lead ECG.

METHODS

From June 2019 to February 2021, we conducted a cross-sectional study wherein we performed transoesophageal echocardiography (TEE) in patients with AIS and sinus rhythm on 12-lead ECG who were referred for detection of LAA thrombus. After TEE, all patients underwent 24-hour ECG monitoring to screen for paroxysmal AF. Predictors of LAA thrombus were determined using logistic regression analysis.

RESULTS

Overall, 223 patients (age: 66.2±11.3 years, men: 61.4%) were included in the study. LAA thrombus was detected in 15 patients (6.7%). Paroxysmal AF was detected in 14 of the 15 patients during 24-hour ECG monitoring. Compared with the non-thrombus group, the thrombus group had a statistically significant higher rate of spontaneous echo contrast (SEC), longer LAA, lower peak LAA emptying velocity and predominantly bilateral stroke. In the adjusted model, the presence of SEC increased the probability of LAA thrombus (OR 9.04; 95% CI 2.12 to 38.54; p=0.003).

CONCLUSIONS

In patients with AIS and sinus rhythm on 12-lead ECG, our study revealed that the prevalence of LAA thrombus was 6.7% with the most prevalent aetiology being paroxysmal AF. The presence of SEC can be a predictor of LAA thrombus in these patients.

Expert opinion paper on cardiac imaging after ischemic stroke

This expert opinion paper on cardiac imaging after acute ischemic stroke or transient ischemic attack (TIA) includes a statement of the "Heart and Brain" consortium of the German Cardiac Society and the German Stroke Society. The Stroke Unit-Commission of the German Stroke Society and the German Atrial Fibrillation NETwork (AFNET) endorsed this paper. Cardiac imaging is a key component of etiological work-up after stroke. Enhanced echocardiographic tools, constantly improving cardiac computer tomography (CT) as well as cardiac magnetic resonance imaging (MRI) offer comprehensive non- or less-invasive cardiac evaluation at the expense of increased costs and/or radiation exposure. Certain imaging findings usually lead to a change in medical secondary stroke prevention or may influence medical treatment. However, there is no proof from a randomized controlled trial (RCT) that the choice of the imaging method influences the prognosis of stroke patients. Summarizing present knowledge, the German Heart and Brain consortium proposes an interdisciplinary, staged standard diagnostic scheme for the detection of risk factors of cardio-embolic stroke. This expert opinion paper aims to give practical advice to physicians who are involved in stroke care. In line with the nature of an expert opinion paper, labeling of classes of recommendations is not provided, since many statements are based on expert opinion, reported case series, and clinical experience.

The effect of TEE on treatment change in patients with acute ischemic stroke

Background and purpose

Ischemic stroke is a widespread disease carrying high morbidity and mortality. Transesophageal echocardiography (TEE) is considered an important tool in the work-up of patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA) patients; its utility is limited by a semi-invasive nature. The purpose of this study was to evaluate the probability of treatment change due to TEE findings (yield) in the work-up of AIS and TIA patients.

Methods

Retrospective data on patients with AIS or TIA who underwent TEE examination between 2000–2013 were collected from the institutional registry.

Results

The average age of 1284 patients who were included in the study was 57±10.4, 66% of patients were male. The most frequent TEE findings included aortic plaques in 54% and patent foramen ovale (PFO) in 15%. TEE findings led to treatment change in 135 (10.5%) patients; anticoagulant treatment was initiated in 110 of them (81%). Most common etiology for switch to anticoagulation was aortic plaques (71 patients); PFO was second most common reason (26 patients). Significant TEE findings (thrombus, endocarditis, tumor) were found in 1.9% of patients, they were more common in young patients (<55; 56% of the patients).

Conclusions

The beginning of anticoagulation treatment in patients with thick and complicated plaques was found frequently in our study. Significant TEE findings, were infrequent, constituted an absolute indication for treatment change and were more common in younger patients.

[Multiple Stroke Syndrome Caused by Air Embolism Following Removal of a Central Venous Catheter]

The removal of a central venous catheter on a ward leads to a paradox air embolism in a 53-year-old male patient with an unknown ventricular septal defect. The patient undergoes sufficient cardiopulmonary resuscitation but suffers from a multiple stroke syndrome with serious neurological deficits.

Cardiac Imaging After Ischemic Stroke or Transient Ischemic Attack

PURPOSE OF REVIEW

Cardiac imaging after ischemic stroke or transient ischemic attack (TIA) is used to identify potential sources of cardioembolism, to classify stroke etiology leading to changes in secondary stroke prevention, and to detect frequent comorbidities. This article summarizes the latest research on this topic and provides an approach to clinical practice to use cardiac imaging after stroke.

RECENT FINDINGS

Echocardiography remains the primary imaging method for cardiac work-up after stroke. Recent echocardiography studies further demonstrated promising results regarding the prediction of non-permanent atrial fibrillation after ischemic stroke. Cardiac magnetic resonance imaging and computed tomography have been tested for their diagnostic value, in particular in patients with cryptogenic stroke, and can be considered as second line methods, providing complementary information in selected stroke patients. Cardiac imaging after ischemic stroke or TIA reveals a potential causal condition in a subset of patients. Whether systematic application of cardiac imaging improves outcome after stroke remains to be established.

Cardiac imaging after ischemic stroke : Echocardiography, CT, or MRI?

About 20–25% of all ischemic strokes are of cardioembolic etiology, with atrial fibrillation and heart failure as the most common underlying pathologies. Diagnostic work-up by noninvasive cardiac imaging is essential since it may lead to changes in therapy, e.g., in—but not exclusively—secondary stroke prevention. Echocardiography remains the cornerstone of cardiac imaging after ischemic stroke, with the combination of transthoracic and transesophageal echocardiography as gold standard thanks to their high sensitivity for many common pathologies. Transesophageal echocardiography should be considered as the initial diagnostic tool when a cardioembolic source of stroke is suspected. However, to date, there is no proven benefit of transesophageal echocardiography-related therapy changes on the main outcomes after ischemic stroke. Based on the currently available data, cardiac computed tomography and magnetic resonance imaging should be regarded as complementary methods to echocardiography, providing additional information in specific situations; however, they cannot be recommended as first-line modalities.

Diagnostic Accuracy of Electrocardiogram-Gated Thoracic Computed Tomography Angiography without Heart Rate Control for Detection of Significant Coronary Artery Stenosis in Patients with Acute Ischemic Stroke: A Comparative Study

Objective

To compare the diagnostic performance of electrocardiogram (ECG)-gated thoracic computed tomography angiography (TCTA) without heart rate (HR) control in ischemic stroke patients with coronary CTA (CCTA) in non-stroke patients for detection of significant coronary artery stenosis.

Materials and Methods

From September 2009 through August 2014, we retrospectively enrolled 138 consecutive patients diagnosed with acute ischemic stroke who had undergone ECG-gated TCTA and conventional coronary angiography (CCA). Over the same period, we selected 167 non-stroke patients with suspected or known coronary artery disease who had undergone CCTA and CCA. With CCA as the reference standard, the diagnostic performance of TCTA and CCTA for identification of significant coronary stenosis (diameter reduction ≥ 50%) was calculated.

Results

There was no significant difference in baseline characteristics between TCTA (n = 132) and CCTA (n = 164), except for the higher prevalence of atrial fibrillation in the stroke group. There was significant difference (p < 0.001) between TCTA and CCTA in average HR (68 ± 12 vs. 61 ± 10 beats per minute) and image quality score (1.3 ± 0.6 vs. 1.2 ± 0.6). Significant coronary stenosis was identified in 101 (77%) patients, 179 (45%) vessels, and 293 (15%) segments of stroke patients, and in 136 (83%) patients, 259 (53%) vessels, and 404 (16%) segments of non-stroke patients. Diagnostic performance on a per-vessel and per-patient basis was similar in both TCTA and CCTA groups. There was only significant difference in area under receiver-operating characteristic curve between TCTA and CCTA groups (0.79 vs. 0.87, p < 0.001) on per-segment basis.

Conclusion

Electrocardiogram-gated TCTA without HR control facilitates the identification of significant coronary stenosis in patients with ischemic stroke.

Early Echocardiography Has a Low Yield in Patients with Transient Ischemic Attack

STUDY OBJECTIVE

Current guidelines recommend patients presenting with transient ischemic attack (TIA) undergo echocardiography to evaluate for a cardiac source. However, echocardiography is not available daily at many centers. We assessed the yield from early transthoracic echocardiography (TTE) in consecutive patients with TIA evaluated in an emergency department observation unit (EDOU) protocol.

METHODS

This observational cohort study took place in an academic medical center from January 1, 2011 to July 31, 2013. Patients seen in the emergency department, assigned to the EDOU for a TIA accelerated diagnostic protocol and discharged with a diagnosis of TIA were included. We retrospectively collected baseline patient characteristics, ABCD2 score, neuroimaging, telemetry, TTE, and 3-month clinical outcomes.

RESULTS

Of 236 subjects (mean age 62 ± 15 years, 68% female, 57% African American, 17% with history of stroke, 27% with history of cardiac disease, mean ABCD2 score 3.8 ± 1.5, mean EDOU length of stay 18.6 ± 6.2 hours), abnormal bedside cardiac examination was identified in 19 (8%) patients, abnormal electrocardiogram (ECG)/telemetry in 41 (17%), and abnormal TTE in 64 (27%), 41 of which suggested a patent foramen ovale. Among 136 (58%) patients with no previous cardiac disease or stroke, a normal bedside cardiac examination, and normal ECG/telemetry, TTE identified no high-risk cardiac causes.

CONCLUSION

In patients with TIA presenting to an EDOU with no previous cardiac disease or stroke, normal cardiac examination, and normal ECG/telemetry, early TTE had a low yield for identifying high-risk cardiac causes. In EDOUs where TTE is not available daily, outpatient TTE for this patient subgroup may be considered to limit prolonged lengths of stay.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Peripheral Arterial Embolism: Prevalence, Outcome, and the Role of Echocardiography in Management

The aims of this study were to review the prevalence and outcome of all surgically treated upper and lower limb emboli presenting to one vascular unit in the last 3 years and to compare transthoracic with transesophageal echocardiography for defining the source of the embolus. All patients who underwent surgical embolectomy for acute limb ischemia from January 2001 to June 2004 were reviewed. Transthoracic and transesophageal echocardiography were carried out on a subset of consecutive unselected patients. Forty-two patients, with a mean age of 80 years, underwent surgical embolectomy from January 2001 to June 2004 (M/F 1:1.8): 27 for lower limb ischemia and 15 for upper limb ischemia. Two thirds of these patients were found to be in atrial fibrillation at presentation (n=28), of whom less than a third were receiving anticoagulants or antiplatelet agents (n=8). The mean hospital stay was 15 days with 36 patients (86%) being fully anticoagulated before discharge from hospital. The 30-day mortality rate was 11% (n=3/27) with 5 patients requiring fasciotomies (12%) and 3 patients requiring an amputation of the lower limb (11%). Postoperatively, 34 patients (81%) had transthoracic echocardiography (TTE), which demonstrated a source or potential source for thrombus in 19 (56%). Fifteen patients (36%) had transesophageal echocardiography (TEE), which changed the subsequent management in 3 patients. All patients in whom TEE altered clinical management would have required this investigation if standard clinical guidelines were followed. TEE did not identify any additional patients with cardiac embolic sources that were not detected by TTE. Arterial limb emboli are still prevalent, but limb salvage and mortality rates appear to be improving. Despite clear guidelines on anticoagulation for patients in atrial fibrillation, many are not receiving appropriate treatment. Transthoracic echocardiography is a good screening tool for detecting a potential cardiac source for peripheral embolism, with transesophageal echocardiography being reserved for specific indications.

Dabigatran exhibits low intensity of left atrial spontaneous echo contrast in patients with nonvalvular atrial fibrillation as compared with warfarin

The presence of spontaneous echo contrast (SEC) in the left atrium has been reported to be an independent predictor of thromboembolic risk in patients with atrial fibrillation (AF). Dabigatran was associated with lower rates of stroke and systemic embolism as compared with warfarin when administered at a higher dose. Between July 2011 and October 2015, nonvalvular AF patients treated with warfarin or dabigatran who had transesophageal echocardiography prior to ablation therapy for AF were enrolled. The intensity of SEC was classified into four grades, from 0 to 3. Univariate and multivariate analysis was performed to analyze factors associated with SEC. Sixty-five patients were on dabigatran and 65 were on warfarin, with the prothrombin time in therapeutic range. There were no significant differences in the age, CHADS2 score, left atrial dimension, and left atrial appendage flow between the two groups. However, there were more grade 2 or higher patients with left atrial SEC in the warfarin group (n = 20) than in the dabigatran group (n = 2) (p < 0.001). When multivariate regression analysis was performed, grade 2 or higher left atrial SEC was independently associated with no dabigatran usage in addition to high brain natriuretic peptide level and high incidence of diabetes mellitus or persistent AF. Thus, dabigatran exhibited low intensity of left atrial SEC in nonvalvular AF patients as compared with warfarin.

The value of transesophageal echocardiography in the investigation and management of cryptogenic cerebral ischemia: a single-center experience

The diagnostic utility of transesophageal echocardiography (TEE) has often been challenged in patients with cryptogenic stroke (CS). We estimated the prevalence of different findings on TEE examination of CS patients, their impact on secondary stroke prevention and the presence of potential age or gender disparities. We reviewed all TEE examinations that were performed in a single echocardiography laboratory during a 7-year-old period to identify CS patients that underwent investigation with TEE. Of the 518 total TEE examinations, we identified 88 CS patients. TEE revealed abnormal findings in 69.3 % of them. Patent foramen ovale (PFO) and atrial septal aneurysm (ASA) were identified in 30.6 and 22.7 % of the patients. Ascending aorta and aortic arch atheromatosis was present in 26.1 % of the patients, with complex atheromatosis diagnosed in 14.7 % of them. Cardiac myxomas were uncovered in 2.3 %. Thrombi in the left atrium and in cardiac valves were reported in 3.4 and 2.3 % of the patients, respectively. Based on TEE findings, the therapeutic management would be very likely modified in 9.1 % of the patients. Subgroup analysis revealed no gender disparities on the prevalence of TEE findings and in secondary stroke prevention, while linear regression analyses revealed significant associations of age with the prevalence of PFO, ASA, aorta atheromatosis and complex aorta atheromatosis. TEE examination should be included in the diagnostic work-up of all CS patients, irrespective of age and gender status, since it can reveal potential sources of embolism and has a significant impact for secondary stroke prevention.

Lambl's Excrescences: Association with Cerebrovascular Disease and Pathogenesis

BACKGROUND

Lambl's excrescences (LEx) are detected by transesophageal echocardiography (TEE) and are characterized as thin, elongated, and hypermobile structures located at the leaflets' coaptation point of the heart valves. The association of LEx with cerebrovascular disease (CVD) is still undefined and yet patients with LEx and suspected CVD receive unproven effective antiplatelet or anticoagulant therapy or even undergo valve surgery. Also, the association of LEx with aging and atherogenic, inflammatory, or thrombogenic parameters has not been reported.

METHODS

Seventy-seven patients with systemic lupus erythematosus (SLE) (71 women, age 37 ± 12 years) and 26 age- and sex-matched healthy controls (22 women, age 34 ± 11 years) prospectively underwent routine history and physical exam, transcranial Doppler, brain MRI, TEE, carotid duplex, and clinical and laboratory evaluations of atherogenesis, inflammation, platelet activity, coagulation, and fibrinolysis. Subjects without stroke/TIA on enrollment (with and without LEx) had a median follow-up of 57 months.

RESULTS

On enrollment, 33 (43%) of 77 patients had CVD manifested as acute stroke/TIA (23 patients), cerebromicroembolism by transcranial Doppler (17 patients), or cerebral infarcts by MRI (14 patients). Mitral or aortic valve LEx were equally frequent in healthy controls (46%) as in patients with and without any CVD (39 and 43%), stroke/TIA (35 and 43%), cerebromicroembolism (41 and 42%), or cerebral infarcts (36 and 43%) (all p ≥ 0.72). Also, other mechanisms for CVD other than LEx such as Libman-Sacks vegetations, patent foramen ovale or interatrial septal aneurysm, aortic or carotid atherosclerosis, or thrombogenesis were found in ≥94% of patients with CVD. In addition, 36 subjects with and 44 without LEx had similar low incidence of stroke/TIA (1 (1.3%) and 2 (2.5%), respectively, p = 1.0) during follow-up. Finally, LEx were not associated with aging, atherogenic risk factors, atherosclerosis, inflammation, or thrombogenesis.

CONCLUSIONS

In this study, LEx are similarly prevalent in healthy controls and SLE patients, are not associated with CVD, and are not associated with pathogenic risk factors. Therefore, the study findings suggest that LEx may not be cardioembolic substrates, may not represent pathologic valve structures, and may not require therapy.

Predictors of Recurrent Stroke in Patients with Ischemic Stroke: Comparison Study between Transesophageal Echocardiography and Cardiac CT

PURPOSE

To investigate cardiac computed tomographic (CT) findings predictive of recurrent stroke in patients with ischemic stroke and determine the incremental risk stratification benefit of cardiac CT findings compared with transesophageal echocardiography (TEE) findings in patients with ischemic stroke.

MATERIALS AND METHODS

This single-center prospective study protocol was approved by the institutional review boards, and written informed consent was obtained from all patients. Among 548 consecutive patients, 374 patients with ischemic stroke (254 men and 120 women, with a mean age of 63.1 years) who underwent TEE and cardiac CT were prospectively enrolled in this study. TEE and cardiac CT images were assessed for cardioembolic sources, including thrombus, tumor, spontaneous echo contrast, valvular vegetation, atrial septal aneurysm, patent foramen ovale, and aortic plaque. The primary end point was stroke recurrence. Prognostic factors were assessed with Cox univariate and multivariate analysis. The integrated area under the receiver operating characteristic curve was calculated to compare the prognostic abilities of CT and TEE parameters.

RESULTS

During a median follow-up period of 433 days, there were a total of 28 recurrent stroke events. The TEE parameter of plaque complexity (hazard ratio, 13.512; 95% confidence interval: 3.668, 49.778; P < .001) and CT parameter of plaque complexity (hazard ratio, 32.538; 95% confidence interval: 7.544, 140.347; P < .001) were predictors of recurrent stroke. The time-dependent receiver operating characteristic curve analysis demonstrated no significant differences in prediction of recurrent stroke between TEE and CT parameters (integrated area under the receiver operating characteristic curve, 0.812 vs 0.840, respectively).

CONCLUSION

Complex aortic plaque evaluated with cardiac CT and TEE was associated with an increased risk of stroke recurrence in patients with ischemic stroke.

Impact of transesophageal echocardiography on management in patients with suspected cardioembolic stroke

Transesophageal echocardiography (TEE) is frequently performed in patients with acute ischemic cerebrovascular events to exclude a cardioembolic source. We aimed to determine the clinical impact of TEE on management. This is a retrospective single-center study of 1,458 consecutive patients hospitalized with acute ischemic stroke or transient ischemic attack who underwent TEE for evaluation of a suspected cardioembolic cause. Significant TEE findings were determined for each patient as recorded on the TEE report. The medical record was reviewed for baseline, clinical, and demographic variables and to determine whether significant management changes occurred as a result of the TEE findings. Potential significant changes in management included initiation of anticoagulation, placement of a patent foramen ovale (PFO) closure device, initiation of antibiotic therapy for endocarditis, surgical PFO closure, other cardiac surgery, and coil embolization of a pulmonary arteriovenous malformation. A significant change in management occurred in 243 patients (16.7%); 173 (71%) underwent treatment for PFO with a percutaneous PFO closure device (n = 100), initiation of chronic systemic anticoagulation (n = 68), or surgical PFO closure (n = 5). Additional findings leading to a change in management included endocarditis (n = 20), aortic arch atheroma (n = 14), intracardiac thrombus (n = 13), pulmonary arteriovenous malformation (n = 2), aortic valve fibroelastoma (n = 2), other valve masses (n = 4), and miscellaneous causes (n = 15). In conclusion, in patients with suspected cardioembolic stroke, TEE findings led to a change in management in 16.7% of patients. Of these, most (71%) were directed at prevention of subsequent paradoxical emboli in patients with PFO.

Left atrial deformation parameters predict left atrial appendage function and thrombus in patients in sinus rhythm with suspected cardioembolic stroke: a speckle tracking and transesophageal echocardiography study

The aim of this study was to evaluate left atrial deformations using speckle tracking echocardiography for predicting left atrial appendage (LAA) thrombus in patients with suspected cardioembolic stroke who were in normal sinus rhythm. A total of 153 ischemic stroke patients (89 males, 64 females) in sinus rhythm who were suspected of having cardioembolism were included in the study. The patients underwent conventional two-dimensional (2D) echocardiogram and 2D speckle tracking echocardiogram of the left atrium. Left atrial peak strain (LA-4C-RES) and left atrial precontraction strain (LA-4C-PUMP) were measured. Patients were divided into 2 groups according to the presence of thrombus in the LAA in transesophageal echocardiography. Both LA-4C-RES and LA-4C-PUMP values were found to be significantly lower in patients with LAA thrombus (11.8 ± 1.4% vs. 33 ± 12%, P < 0.001 and 5.8 ± 1.3% vs. 14.2 ± 5.3%, P < 0.001, respectively). A good inverse correlation was present between LA-4C-RES values and LAA morphologic parameters (with LAA area: r = -0.70, P < 0.001, with LAA length: r = -0.60, P < 0.001), and a good positive correlation was present with LAA emptying velocity with pulse Doppler (r = 0.74, P < 0.001). The area under the receiver-operating characteristic curve of the LA-4C-RES was 0.94 (0.90-0.98, P < 0.001), for the LA-4C-PUMP, the area was 0.92 (0.87-0.96, P < 0.001) to predict LAA thrombus. Left atrial deformation parameters measured by 2D speckle tracking method was found to predict impaired LAA functions and the presence of LAA thrombus in ischemic stroke patients with suspected cardioembolism, but who are in sinus rhythm.

Influence of transoesophageal echocardiography on therapy and prognosis in young patients with TIA or ischaemic stroke

Objective. To determine the influence of transoesophageal echocardiography (TEE) on therapy and prognosis in patients with cryptogenic transient ischaemic attack (TIA) or ischaemic stroke under the age of 50 years.Methods and results. We evaluated all patients aged 50 and under who were referred to our university hospital for cryptogenic TIA or ischaemic stroke during the period 1 January 1996 to 31 December 2004. All patients underwent both transthoracic echocardiography (TTE) and TEE. Patients with known pre-existent heart disease, such as atrial fibrillation, were excluded. Eighty-three patients with TIA (22) and ischaemic stroke (61) were enrolled. Mean age was 39+/-8 years (range 18 to 50). In 30% of the patients TEE detected one or more potential cardioembolic source, compared with 10% for TTE (p=0.003). Standard treatment (aspirin 38 mg daily) was changed in 7% of the patients due to the TEE findings. Complete followup was obtained in 93% with an average of 5+/-3 years. Twelve recurrences occurred; two out of six patients (33%) with therapy change and ten out of 71 (14%) of the patients without therapy change had a recurrent TIA or ischaemic Stroke.Conclusion. In patients with cryptogenic TIA or ischaemic stroke, TEE is superior to TTE in the detection of a potential cardiac source of embolism. However, findings obtained by TEE only influence the already initiated treatment in a small percentage of patients. The recurrence rate both in the group with and without therapy change is high. (Neth Heart J 2009;17:373-7.).

Atrioventricular thrombus in a 14-year-old patient: a case report

Right atrioventricular thrombus was diagnosed by echocardiography in a 14-year-old boy. Thrombus was reached through the right ventricle to the pulmonary artery and it was caused to tricuspit valve insufficiency. Surgical thrombectomy was performed and, he was treated with oral anticoagulation in postoperative period.

Transesophageal echocardiography for the evaluation and management of patients with cerebral ischemia

To prevent recurrent strokes and transient ischemic attacks, considerable attention is devoted to investigating the etiology of acute cerebral ischemia in the large subpopulation of patients without an easily identifiable cause. In general, transthoracic echocardiography is an insensitive tool for the evaluation of patients with cerebral ischemia, unless clinical signs and/or symptoms of cardiac disease are present. Transesophageal echocardiography (TEE), because of its increased sensitivity for aortic arch atheromata, atrial septal pathology, left atrial thrombi, and valvular abnormalities, is the preferred cardiac imaging modality, especially in young patients, older patients with hypertension or systemic atherosclerosis, and patients with prosthetic heart valves. This paper reviews the prognostic and therapeutic impact of TEE in patients with cerebral ischemia, specifically focusing on the ability of information obtained by this technique to alter patient management and improve risk stratification.

Current incidence of peripheral arterial embolism and role of echocardiography

We reviewed the incidence and outcome of all cases of upper and lower limb embolism surgically treated in our vascular unit, from January 2001 to June 2006, to assess the role of transthoracic and transesophageal echocardiography in defining the source of the embolus. Transthoracic echocardiography was carried out postoperatively, and patients in whom the embolic source was not found underwent transesophageal echocardiography. There were 85 patients (mean age, 69 years) who underwent embolectomy: 58 for lower and 27 for upper limb ischemia. The source or potential source of thrombus was demonstrated in 17 (20%) patients after transthoracic echocardiography. Fifty-three patients had transesophageal echocardiography, the source of embolism was found in 85%, and the subsequent management was changed in 47% of them. Arterial limb emboli are still prevalent in developing countries. Transthoracic echocardiography is a good screening tool for detecting a potential cardiac source of peripheral embolism, with transesophageal echocardiography being reserved for specific indications.

Therapeutic implications of transesophageal echocardiography after transthoracic echocardiography on acute stroke patients

Background

The role of transesophageal echocardiography (TEE) in the evaluation of acute stroke patients is still ill-defined. We conducted a prospective observational study to find the prevalence of TEE findings that indicate anticoagulation as beneficial, in acute ischemic stroke patients without indication for anticoagulation based on clinical, electrocardiographic and transthoracic echocardiography (TTE) findings.

Methods

We prospectively studied all patients referred to our laboratory for TTE and TEE. Patients were excluded if the diagnosis was not acute ischemic stroke or if they had an indication for anticoagulation based on clinical, electrocardiographic, or TTE data. Patients with TEE findings that might indicate anticoagulation as beneficial were identified.

Results

A total of 84 patients with acute ischemic stroke and without indication for anticoagulation based on clinical and electrocardiographic or TTE data were included in the study. Findings indicating anticoagulation as beneficial were found in 32.1%: spontaneous echo contrast (1.2%), complex aortic atheroma (27.4%), thrombus (8.3%), and simultaneous patent foramen ovale and atrial septal aneurysm (2.4%).

Conclusions

The results of our study show that TEE can have therapy implications in 32.1% of ischemic stroke patients in sinus rhythm and with TTE with no indication for anticoagulation.

ApoB/ApoA-I ratio in young patients with ischemic cerebral stroke or peripheral arterial disease

Although smoking and hypertension are classic risk factors for atherothrombotic diseases, the relationship of dyslipidemia and vascular diseases, other than myocardial infarction, is less clearly established, especially in young subjects. In the current study, a detailed analysis of the lipid and apolipoprotein profiles was conducted in young patients of ischemic cerebral stroke (IS) and peripheral arterial disease (PAD). Plasma levels of C-reactive protein (hs-CRP), total cholesterol (TC), high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), triglycerides (TG), and apolipoproteins A-I (ApoA-I) and apolipoproteins B (ApoB), which include the ApoB/ApoA-I ratio, were analyzed in a group of 81 patients who presented with IS (n = 46) or PAD (n = 35) as well as in 167 control subjects. Significant differences were observed for hs-CRP, TC, HDLc, LDLc, TG, ApoA-I, and ApoB levels, as well as for the ApoB/ApoA-I ratio, between the control and the IS or PAD groups. However, after adjustment for sex, age, smoking, hypertension, hs-CRP, and dyslipidemia (LDLc, TC, HDLc, TG, ApoA, ApoB, and ApoB/ApoA-I ratio), hs-CRP, ApoB, and the ApoB/ApoA-I ratio were independently associated with increased risks of IS or PAD. Increased ApoB/ApoA-I ratio and hs-CRP levels are independently associated with occurrence of IS and PAD in young patients and are significant markers of alterations on lipid and apolipoproteic profiles and inflammatory responses, respectively, in these patients.

Risk factors of young ischemic stroke in Qatar

OBJECTIVES

There is limited information about risk factors of young ischemic stroke in Qatar. The aim of this study was to describe the risk factors and subtypes of young ischemic stroke among Qatari and non-Qatari residents.

PATIENTS AND METHODS

Hospital based prospective observational study involving all young adults (15-45 years of age) admitted to Hamad General Hospital with first-ever ischemic stroke from September 2004 to September 2005. A stroke was defined according to WHO criteria.

RESULTS

Stroke was confirmed in 40 (32 males and 8 females). Their ages ranged from 17 to 44 years (mean 37.1+/-13.27). Thirty (75%) of the patients were non-Qatari. The most common risk factors were hypertension 16 (40%), diabetes mellitus 13 (32.5%), hypercholesterolemia 11 (27.5%), smoking 11 (27.5%), and alcohol intake 9 (22.5%). Regarding stroke subtypes, lacunar stroke syndrome (LACS) was diagnosed in 17 (42.5%), total anterior circulation stroke syndrome (TACS) in 16 (40%), partial anterior circulation stroke syndrome (PACS) in 5 (12.5%) and posterior circulation stroke syndrome (POCS) in 2 (5%). Partial anterior circulation stroke syndrome (PACS) was observed with a higher frequency in Qatari patients compared with non-Qataris (p=0.009), whereas total anterior circulation stroke syndrome (TACS) was observed more in non-Qatari than in Qatari patients (p=0.03). Average hospital stay was 18 days. In-hospital mortality was 2.5%.

CONCLUSION

The risk factors of ischemic stroke in young adults are numerous. The most common were hypertension, diabetes mellitus, hypercholesterolemia, smoking and alcohol intake. Only one Indonesian male patient with POCS died in the hospital.

Intracardiac thrombi in pediatric patients: presentation profiles and clinical outcomes

We document the presentation profiles, treatment strategies, and clinical outcomes in a relatively large cohort of pediatric patients with intracardiac thrombi (ICT). We performed a retrospective review of patients diagnosed with ICT by echocardiography at a tertiary pediatric hospital during a 10-year period. These patients received medical therapy or thrombectomy. We provided echocardiographic descriptions of the ICT-size, chamber location, and mobility/morphology. The outcome measures were ICT (persistence, resolution, or embolization), effectiveness of therapy, and patient morbidity and mortality. There were 40 ICT diagnosed in 31 patients (22 males and 9 females). Mean age at diagnosis was 8.8 years (range, 15 days to 18 years). Overall mortality was 12/31 patients (39%); only one death was attributed to ICT embolization. Embolic events occurred in 4/31 patients (13%). The most common initial therapies included heparin infusion (n = 15), warfarin (n = 7), and aspirin (n = 7). The ICT resolved with medical therapy alone in 19/30 patients (63%). One patient required surgical thrombectomy. The cohort was divided into group 1 (dilated cardiomyopathy), group 2 (status post Fontan operation), and group 3 (other diagnoses). In group 1 (n = 11), there were 8 deaths. Embolization occurred in 2/5 large ICT, resulting in cerebral infarction and death (n = 1) and renal infarction (n = 1). The most common ICT location was the left ventricle (n = 10). Severe ventricular systolic dysfunction was present in 10/11 patients (91%). In group 2 (n = 9), there was 1 death. Embolization occurred in 1/7 large ICT, resulting in seizures and temporary paresis. All ICT were located in the Fontan pathway. Severe ventricular systolic dysfunction was present in 2/9 patients (22%). In group 3 (n = 11), there were 3 deaths. Embolization occurred in 1/9 small ICT, resulting in coronary emboli. ICT are most commonly diagnosed in pediatric patients with dilated cardiomyopathy or patients status post Fontan operation. The majority of ICT resolve with medical therapy. Larger ICT tend to embolize more frequently, and the morbidity secondary to embolization is significant. Rarely is mortality due to ICT embolization. The prognosis is poor for patients with left ventricular ICT or ICT in the presence of ventricular systolic dysfunction.

Subtipos etiológicos de accidente cerebrovascular isquémico en adultos entre 18 y 45 años: estudio de una serie de 93 pacientes

OBJECTIVE

This work studied the etiologic subtypes of ischemic stroke in young adults in La Coruña and compared this with previous reports.

PATIENTS AND METHODS

From January 2002 to December 2004, a total of 2716 patients with ischemic cerebral infarcts, transient ischemic accidents or venous infarcts were admitted in our hospital. Only 93 patients were between 18 to 45 years old. This group of 93 patients was studied retrospectively and was extensively evaluated according to a standardized protocol to analyze the distribution of stroke subtypes.

RESULTS

Cerebral infarction was diagnosed in 63%, transient ischemic attack in 24.7% and venous infarction in 11.8% of the cases. Regarding stroke subtype, stroke of undetermined etiology was the most common subtype diagnosed in 37.6% of cases, non-arteriosclerosis vasculopathy in 16.1%, hematology etiology in 9.7%, cardioembolism in 8.6% and stroke of small-vessel occlusion was the least common in 4.3%. The four most common risk factors were smoking (50.5%), hyperlipidemia (31.2%) and hypertension (22.6%) and alcoholism (16.1%).

CONCLUSIONS

The results obtained in our series are similar to those published in the literature. Cerebral infarct accounted for 63% of the cases. A probable cause of ischemic stroke was identified en 62% and remained unexplained in 38% of the cases. Stroke of undetermined etiology was the most common subtype. The high incidence was not explained by a higher prevalence of premature atherosclerotic vasculopathy and a battery of extensive examinations is indicated to elucidate the etiology.

Prevalence and clinical importance of spontaneous echo contrast within the carotid artery in patients with ischemic cerebrovascular disease

OBJECTIVE

Spontaneous echo contrast (SEC) is composed of numerous microechoes swirling in the cardiovascular lumen, usually appearing during blood stasis. This study aimed to clarify the clinical importance of SEC in the carotid artery (CA) in patients with ischemic cerebrovascular disease (ICVD).

METHODS

In 264 CAs of 132 consecutive patients with ICVD and in 40 CAs of 20 healthy control subjects, SEC was classified as none, faint, or dense, and CA abnormalities, including plaque, plaque ulcer, mural thrombus, and internal CA stenosis, were assessed with 10-MHz sonography.

RESULTS

The overall prevalence of SEC was greater in CAs of patients with ICVD (164/264 [62%]) than in CAs of control subjects (6/40 [15%]; P < .0001). Dense SEC was more specifically detected in CAs of ICVD with the prevalence of 81 (31%) of 264, which was greater than that of controls (1/40 [3%]; P = .0002). Dense SEC was more frequently detected in CAs with plaque (38/98 [39%]) than in those without (43/166 [26%]; P = .0285), in CA plaque with ulcerative lesions (7/10 [70%]) than in those without (31/88 [35%]; P = .0325), in CA plaque with a thrombus (11/12 [92%]) than in those without (27/86 [31%]; P < .0001), and in CAs with severe stenosis (11/13 [85%]) than in those with mild stenosis (25/75 [33%]; P = .0005) and in those without stenosis (45/176 [26%]; P < .0001).

CONCLUSIONS

Dense SEC was frequently observed in CAs of patients with ICVD, especially in those with local atheromatous lesions, although the influence of systemic factors could not be excluded. Dense SEC within a CA may be a marker of ICVD.

Mild Left Ventricular Dysfunction Is Associated with Thrombogenicity in Cardioembolic Stroke

BACKGROUND

Transesophageal echocardiography (TEE) has been recognized as a valuable tool for identifying the left cardiac thrombus (LCT) or spontaneous echocardiographic contrast (SEC). We aimed to identify risk groups where TEE should be performed in patients with suspected cardioembolic stroke according to magnetic resonance imaging analysis.

METHODS

One hundred and forty-six patients (mean age 64.7 +/- 11.8 years, 101 males) with suspected cardioembolic stroke were analyzed. We used TEE for the presence of LCT and/or SEC as indication of thrombogenicity. We evaluated the association between thrombogenicity and demographic features, stroke risk factors and echocardiographic variables.

RESULTS

The study included 40 patients (27.3%) who showed thrombogenicity (10 LCT and 30 SEC). The independent echocardiographic variables of thrombogenicity were atrial fibrillation (OR 7.14; 95% CI 2.62-19.48; p < 0.001) and left ventricular ejection fraction </=50% (OR 4.01; 95% CI 1.40-11.49; p = 0.01).

CONCLUSION

We recommend that TEE should be considered in patients with mildly reduced left ventricular dysfunction (ejection fraction </=50%) after suspected cardioembolic stroke.

A case series of young stroke in Rome

In this hospital case series study we enrolled 394 consecutive ischemic stroke patients aged 14-47 years, all of whom were submitted to a diagnostic protocol. We evaluated the incidence of cerebral ischemia in young adults, as well as the risk factors and the etiopathogenesis of this pathology. Modified diagnostic criteria adopted from the TOAST and Baltimore-Washington Cooperative Young Stroke Study were used for the etiologic classification. The crude annual incidence rate was 8.8/100,000 (95% CI 7.7-9.9), which is in keeping with the rates reported in comparable registries. Risk factors were distributed as follows: smoking in 56% of patients, hypertension in 23%, dyslipidemia in 15%, migraine in 26%, and diabetes mellitus in 2%. Oral contraceptives were being taken by 38% of the women enrolled. The etiology of stroke in the patients was as follows: cardioembolism in 34%, atherothrombosis in 12%, non-atherosclerotic vasculopathies in 14% (including arterial dissection in 12%), other determined causes in 13%, lacunar stroke in 2.5%, migraine in 1%, and undetermined causes in 24%. Despite its biased sampling frame, this large hospital case series, in which risk factor distribution and etiopathogenesis were investigated, stresses the need for an adequate diagnostic approach in young ischemic patients.

Transesophageal Echocardiography Impacts Management and Evaluation of Patients with Stroke, Transient Ischemic Attack, or Peripheral Embolism

The relative impact of transesophageal echocardiography (TEE) on the management of patients with specific embolic events, namely nonhemorrhagic cerebrovascular accident (CVA), transient ischemic attack (TIA), or peripheral embolism is controversial. The impact of TEE in 234 adult subjects with CVA (n = 141), TIA (n = 59), or peripheral embolism (n = 34) was determined. TEE was diagnostic of a potential embolic source in 61%, 51%, and 62% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). TEE results changed medication or surgical treatment in 32%, 22%, and 32% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). Anticoagulation was started on the basis of TEE findings in 11%, 12%, and 18% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). In 77% of all patients, TEE findings confirmed as appropriate the empiric decision made prior to TEE, to anticoagulate (60%; 12/20) or not to anticoagulate (79%; 168/214). These data demonstrate that TEE findings have a significant and similar impact on the clinical management of patients with various types of potential embolism. Future studies addressing the effectiveness of treatment, guided by TEE findings, in the prevention of recurrent embolic events are needed.

The Role of the 12-Lead ECG as a Screening Test for Cardiac Source of Embolus

BACKGROUND

Investigation for cardiac source of embolus (CSE) is one of the commonest referrals for transthoracic echocardiography (TTE) of hospital inpatients, but has a relatively low-diagnostic yield. We sort to investigate whether 12-lead ECG might be useful in screening patients to obviate the need for TTE, in a subset of patients referred for echocardiographic investigation of cardiac source of embolus.

METHODS

We collected ECG and echo data for 400 consecutively referred inpatients for TTE investigation of possible cardiac source of embolus. We analysed this data for evidence of cardiac source of embolism on TTE in patients with a normal or abnormal ECG.

RESULTS

41/400 (10%) subjects had possible CSE identified on TTE. Diagnostic yield for CSE was higher for those with abnormal compared with normal ECG (17% versus 6%, p<0.001). Of 232/400 (58%) patients with a normal ECG, 200 had a normal TTE (86%). Of the 32 with normal ECG and abnormal TTE, echo found a possible embolic source in 13. Of those 168 (42%) with an abnormal ECG, TTE was normal in 73 and abnormal in 95, of whom 28 patients had an echo that identified a possible cardio-embolic source. ECG, therefore, had a sensitivity of 68%, specificity of 61%, positive predictive value of 0.17 and negative predictive value of 0.94 for detecting possible cardiac sources of embolus.

CONCLUSIONS

Although TTE is a relatively low-yield investigation for the detection of cardiac source of embolus, 12-lead ECG is not sufficiently sensitive to identify the approximately 10% of patients in whom echo will demonstrate a diagnostic abnormality.

Transesophageal echocardiography discloses unexpected cardiac sources of embolus in stroke patients aged more than 45 years

Cerebral embolism from cardiac source is an important cause of stroke, specially in patients younger than 45 years old. OBJECTIVE: To describe the transesophageal echocardiography (TEE) findings in young and non-young stroke patients without any prior evidence of cardiac source for cerebral embolism. METHOD: Transversal study: 523 patients (267 men and 256 women) with ischemic stroke, without any evidence of cardiac abnormality, underwent to TEE. RESULTS: Ten percent were aged 45 years; or less. Left ventricle hypertrophy, left atrial enlargement, spontaneous contrast in aorta, interatrial septum aneurysm, mitral and aortic valve calcification, aortic valve regurgitation, and atherosclerotic plaques in aorta were significantly more frequent in patients aged more than 45 years; 2.8% of non-young patients had thrombus in left heart. CONCLUSION: TEE is widely used to diagnose cardiac source of cerebral embolism in young patients, but it seems to be as useful for older ones, in whom cerebral embolism risk is underestimated; atherogenic and cardioembolic causes may actually coexist, and both should be treated.

Predictors of left atrial spontaneous echocardiographic contrast or thrombus formation in stroke patients with sinus rhythm and reduced left ventricular function

The objective of the present study was to identify predictors of left atrial spontaneous echocardiographic contrast (SEC) or thrombus in patients with stroke with sinus rhythm and left ventricular dysfunction. Of 500 consecutive patients with stroke, 48 with sinus rhythm and reduced left ventricular ejection fractions (EFs) < or =45% were examined. Ten patients presented with SEC or thrombus. The patients with SEC or thrombus had larger left atrial diameters (47 +/- 4 vs 42 +/- 6 mm, p <0.05), smaller EFs (30 +/- 9% vs 38 +/- 8%, p <0.01), and slower left atrial appendage (LAA) flow velocities (42 +/- 13 vs 61 +/- 17 cm/s, p <0.01). Multivariate analysis identified EF < or =35% and LAA flow velocity < or =55 cm/s as predictors of SEC or thrombus (p <0.05). Patients with stroke with sinus rhythm and moderate- to high-grade reduction of the left ventricular EF represent a risk group for a left atrial source of embolism and should undergo transesophageal echocardiography.

Patients With Atrial Fibrillation and Dense Spontaneous Echo Contrast at High Risk

OBJECTIVES

We sought to assess the prognosis of patients with atrial fibrillation (AF) and dense spontaneous echo contrast (SEC) and to determine the incidence of cerebral embolism under continued oral anticoagulation.

BACKGROUND

Patients with AF and dense SEC have an increased risk of cerebral embolism. However, there is little knowledge about the long-term fate and the rate of clinical silent cerebral embolism under continued oral anticoagulation.

METHODS

Between 1998 and 2001, all consecutive patients with AF and dense SEC were included in the study. We performed serial and prospective transesophageal echocardiography, cranial magnetic resonance imaging, and clinical examinations during a period of 12 months.

RESULTS

A total of 128 patients with dense SEC and AF were included. The control group consisted of 143 patients with faint SEC and AF. During the follow-up period, three patients (2%) had cerebral embolism with neurologic deficits. A total of eight patients (6%) died due to embolic events, and 19 (15%) patients had silent embolism, as documented on cerebral magnetic resonance imaging. Patients with an event had significantly lower left atrial appendage peak emptying velocities and more commonly had a history of previous thromboembolism and denser SEC, as compared with patients without an event.

CONCLUSIONS

Patients with AF and dense SEC have a high likelihood of cerebral embolism (22%) and/or death, despite oral anticoagulation. Low peak emptying velocities of the left atrial appendage and dense SEC are independent predictors of an event.

Comparison of transthoracic echocardiography with second harmonic imaging with transesophageal echocardiography in the detection of right to left shunts

We compared the use of transthoracic echocardiography with second harmonic imaging after a peripheral intravenous injection of an agitated saline solution with transesophageal echocardiography (TEE) in the detection of right to left shunts at the cardiac and pulmonary level. Second harmonic mode transthoracic echocardiography and TEE are equally sensitive in detecting right to left shunts in patients undergoing a daily routine TEE.

Spontaneous echo contrast: where there's smoke there's fire

Left atrial (LA) spontaneous echo contrast (SEC), or "smoke," is a frequent finding on transesophageal echocardiography (TEE), but it is rarely detected with transthoracic echocardiography. LA SEC is characterized by dynamic smoke-like echoes within the LA cavity or appendage. Most patients with LA SEC have atrial arrhythmias, mitral stenosis, or a mitral valve prosthesis, and they have an enlarged LA, conditions that are associated with LA stasis. Conversely, mitral regurgitation is protective against LA SEC. LA SEC is present in almost all patients with LA thrombus and is associated with previous embolic events in many patient populations. In patients with nonvalvular atrial fibrillation, LA SEC predicts future embolism and death. LA SEC may therefore assist in selecting patients with atrial fibrillation or with mitral stenosis and sinus rhythm who benefit the most from anticoagulation. Hematological studies have shown that LA SEC is a marker of an hypercoagulable state. LA SEC is a manifestation of red cell aggregation, arising from an interaction between red cells and plasma proteins such as fibrinogen, at low shear rates. LA SEC does not require platelets. The detection of LA SEC on ultrasound arises from the increased amplitude of backscatter from red cell aggregates rather than single cells. Patients with LA SEC should be considered for anticoagulant therapy and may require correction of underlying cardiovascular abnormalities. Future directions in LA SEC include further assessment of integrated backscatter for quantification, assessment of its prognostic role in clinically low-risk patients with nonvalvular AF, and novel pharmacological treatment.