Usefulness of transesophageal echocardiography in identifying small left ventricular apical thrombus

Identification of a small thrombus in the left ventricle identified on iodine maps derived from dual-source photon-counting detector CT

Transthoracic echocardiography is the main imaging modality to diagnose left ventricular thrombus (LVT), but its efficacy in certain cases is suboptimal. We report a patient in whom an LVT, initially unidentified by transthoracic echocardiography, was successfully diagnosed with iodine maps derived from dual-source photon-counting detector CT (DS-PCD-CT). The 64-year-old male was admitted to our institution following myocardial infarction. Although TTE failed to detect this small LVT, iodine maps derived from CT angiography (which was conducted to evaluate the coronary artery stenosis) revealed its presence. Iodine maps derived from DS-PCD-CT collecting data with high temporal resolution are beneficial to diagnose LVTs.

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.

Effect of abnormal right heart structures on the diagnosis of pulmonary hypertension

The diagnosis of pulmonary hypertension (PH) requires a right heart catheterization (RHC) that reveals a mean pulmonary artery pressure ≥ 25 mmHg. The pulmonary artery catheter traverse the right atrium and ventricle on its way to the pulmonary artery. The presence of abnormal right heart structures, i.e. thrombus, vegetation, benign or malignant cardiac lesions, can lead to complications during this procedure. On the other hand, avoidance of RHC delays the diagnosis and treatment of PH, an approach that might be associated with worse outcomes. This paper discusses the impact of right heart lesions on the diagnosis of PH and suggests an approach on how to manage this association.

Echocardiographic assessment for ventricular assist device placement

While many factors depend on successful implantation and outcome of left ventricular assist devices (LVAD), echocardiography remains an integral part and is vital to the success of this process. Transesophageal echocardiography (TEE) allows interrogation of all the cardiac structures and great vessels. The pre-implantation TEE exam establishes a baseline and may identify potential problems that need palliation. Among these, most significant are aortic insufficiency (AI), intracardiac thrombi, poor right ventricular (RV) function, and intracardiac shunts. The post-implantation exam allows for adequate de-airing of the heart and successful LVAD initiation. The position and flow profiles of the inflow and outflow cannulas of the LVAD may be assessed. Finally, it assists in the astute management and vigilant identification and correction of a number of complications in the immediate post-implantation period. TEE will continue to remain vital to the successful outcomes LVAD patients.

Regional left ventricular function after transapical vs. transfemoral transcatheter aortic valve implantation analysed by cardiac magnetic resonance feature tracking

AIMS

This study analysed the impact of transapical (TA) vs. transfemoral (TF) access site transcatheter aortic valve implantation (TAVI) on post-procedural regional left ventricular (LV) function using cardiac magnetic resonance (CMR) feature tracking (FT).

METHODS AND RESULTS

CMR was performed 3 months after TAVI on 44 consecutive patients with normal LV ejection fraction prior to TAVI. Twenty patients had TA-TAVI, and 24 had TF-TAVI. Standard cine imaging was performed in three standard cardiac long-axis views (two-, four- and three-chamber views). Myocardial peak systolic radial strain (PSRS) and peak systolic longitudinal strain (PSLS) were analysed based on CMR-FT considering 49 segments in each of the three views. There were no differences in PSRS and PSLS for the basal and mid-ventricular segments between TA- and TF-TAVI groups. In contrast, PSRS and PSLS of apical segments and apical cap were reduced in the TA- compared with the TF-TAVI group (PSRS: 15.7 ± 6.4 vs. 35.9 ± 15.7%, respectively, P < 0.001; PSLS: -8.9 ± 5.3 vs. -16.9 ± 4.3%, respectively, P < 0.001). Comparison of all non-apical segments vs. apical segments and apical cap demonstrated no difference in the TF group (PSRS: 34.6 ± 9.0 vs. 35.9 ± 15.7%; respectively, P = 0.702; PSLS: -17.8 ± 4.6 vs. -16.9 ± 4.3%; respectively, P = 0.802). After TA-TAVI, PSRS and PSLS of the apical segments were reduced compared with the non-apical segments (PSRS: 15.7 ± 6.4 vs. 33.5 ± 7.0%, respectively, P < 0.001; PSLS: -8.9 ± 5.3 vs. -15.5 ± 3.5%, respectively, P < 0.001).

CONCLUSION

Apical LV function abnormalities can be detected at 3-month follow-up in all TA-TAVI patients using CMR-FT. TA-TAVI results in significant impairment of apical LV function compared with TF-TAVI.

Detection of Left Ventricular Apical Thrombus With Three-Dimensional Transesophageal Echocardiography

Objective. Left ventricular (LV) thrombosis persists as a clinical challenge in echocardiographic diagnosis and is an important risk factor for perioperative embolic events in cardiac surgery. Appropriate detection and monitoring when thrombus is suspected is critical in surgical planning and in avoiding catastrophic patient outcomes. Case Presentation. The authors present a case of a laminated LV apical thrombus, which was discovered intraoperatively by real-time 3-dimensional (3D) transesophageal echocardiography. Clinical Challenges. The clinical challenges were ( a) LV thrombosis impact on surgical management, ( b) key echocardiographic challenges in diagnosing LV thrombosis, and ( c) role of 3D echocardiography in the diagnostic algorithm. Conclusion. Because of the lack of a gold standard, 2D transthoracic echocardiography remains the imaging modality of choice in assessment; however, there is increasing evidence that 3D technology can be more accurate in intracardiac mass detection and should be considered in the diagnostic algorithm.

Detection of left ventricular thrombus by coronary computed tomography angiography

Left ventricular thrombus is a recognized complication of acute myocardial infarction. The following case report presents a rare case of left ventricular thrombus detection originally via coronary computed tomography angiography, followed by a brief review of imaging modalities that have been used for the detection of left ventricular thrombus in the past.

Improved detection of left ventricular thrombi and spontaneous echocontrast by tissue harmonic imaging in patients with myocardial infarction

BACKGROUND

Tissue harmonic imaging (THI) reduces near-field and side-lobe artifacts. This could improve recognition of cardiac masses, including thrombi and spontaneous echocontrast (SEC), a known thromboembolic risk factor.

OBJECTIVES

We tested the hypothesis that THI improves detection of left ventricular (LV) thrombi and SEC compared with transthoracic fundamental imaging in patients with recent myocardial infarction.

METHODS

In all, 118 consecutive patients with recent myocardial infarction were studied at predischarge. The echocardiographic examination was performed in both fundamental imaging and THI modality and evaluated by 3 skilled and 3 nonexperienced observers for recognition of LV thrombosis and SEC.

RESULTS

THI increased LV thrombi diagnosis by 25% by skilled observers and by 50% by nonexperienced readers, reducing the number of false-positive diagnoses by 67%. Also, compared with fundamental imaging, THI improved recognition of LV SEC by both experienced and nonexperienced observers by 56% and 62%, respectively.

CONCLUSIONS

The improved recognition of LV thrombosis and SEC by THI in patients with myocardial infarction is clinically relevant allowing appropriate treatment and prognostic stratification. Therefore, routine use of THI should be recommended when studying such patients in clinical practice.

Clinical, imaging, and pathological characteristics of left ventricular thrombus: a comparison of contrast-enhanced magnetic resonance imaging, transthoracic echocardiography, and transesophageal echocardiography with surgical or pathological validation

BACKGROUND

Left ventricular (LV) thrombus is a frequent and potentially dangerous complication of ischemic heart disease (IHD). We evaluated the clinical, imaging, and pathology characteristics of confirmed LV thrombus and compared the diagnostic value of contrast-enhanced magnetic resonance imaging (MRI) with transthoracic (TTE) and transesophageal echocardiography (TEE) for the diagnosis of LV thrombi.

METHODS

Between November 1997 and December 2003, 361 patients with IHD had surgical and/or pathological confirmation of presence or absence of LV thrombus. Clinical information and preoperative imaging study reports were retrospectively reviewed regarding detection of thrombus. Comparisons were made between clinical and imaging characteristics of patients with and without confirmed thrombus.

RESULTS

Left ventricular thrombus was present in 106 (29%) of 361 patients in this study. Patients with thrombus had a higher incidence of recent embolic events (6.1% vs 0.8%, P < .005). In 160 patients with all 3 imaging modalities performed within 30 days of surgical or pathological confirmation, contrast-enhanced MRI showed the highest sensitivity and specificity (88% +/- 9% and 99% +/- 2%, respectively) compared with TTE (23% +/- 12% and 96% +/- 3.6%, respectively) and TEE (40% +/- 14% and 96% +/- 3.6%, respectively) for thrombus detection.

CONCLUSIONS

Left ventricular thrombus occurs frequently in patients with IHD and is associated with risk of systemic embolization. Contrast-enhanced MRI provided the highest sensitivity and specificity for LV thrombus when compared to TTE and TEE, and should be considered in the care of patients at high risk of LV thrombus formation.

Left ventricular volume estimation for real-time three-dimensional echocardiography

The application of level set techniques to echocardiographic data is presented. This method allows semiautomatic segmentation of heart chambers, which regularizes the shapes and improves edge fidelity, especially in the presence of gaps, as is common in ultrasound data. The task of the study was to reconstruct left ventricular shape and to evaluate left ventricular volume. Data were acquired with a real-time three-dimensional (3-D) echocardiographic system. The method was applied directly in the three-dimensional domain and was based on a geometric-driven scheme. The numerical scheme for solving the proposed partial differential equation is borrowed from numerical methods for conservation law. Results refer to in vitro and human in vivo acquired 3-D + time echocardiographic data. Quantitative validation was performed on in vitro balloon phantoms. Clinical application of this segmentation technique is reported for 20 patient cases providing measures of left ventricular volumes and ejection fraction.

Left Ventricular Thrombus

Left ventricular thrombus (LVT) is a frequent complication in patients with acute anterior myocardial infarction (MI) and in those with dilated cardiomyopathy (DCM). The clinical importance of LVT lies in its potential to embolize. The current treatment of patients with acute MI centers on reperfusion, and although controversial, the incidence of LVT complicating acute anterior MI is probably reduced when compared with historical controls. Nevertheless, stroke continues to be a clinically important complication of acute MI and is most common in patients with anterior MI, in part secondary to embolization of LVT. Therapeutic anticoagulation during acute MI reduces the incidence of LVT, and long-term anticoagulation has been associated with a reduction in recurrent infarction and ischemic stroke, but carries hemorrhagic risk. Primary treatment strategies for patients with acute MI center on reperfusion therapy followed by antiplatelet agents and pharmacologic blockade of abnormal neurohumoral mechanisms. Strategies to prevent stroke following infarction include risk stratification for development of LVT and embolism. For patients with anterior MI, particularly those with apical akinesis or dyskinesis, therapeutic anticoagulation reduces the number of LVT and cardioembolic strokes. However, the absolute number of ischemic strokes prevented with this strategy may only be marginal, given the anticoagulation risk, particularly if antiplatelet agents are used concurrently. An attractive alternative strategy is echocardiographic evaluation following anterior infarction with therapeutic anticoagulation reserved for those with demonstrable thrombus. The efficacy of this strategy, however, never has been proven in a clinical study. Primary prevention of cardioembolic stroke through therapeutic anticoagulation is controversial in patients with DCM; the greatest benefit would be expected for those with severe left ventricular dysfunction. If LVT is detected during the course of MI or DCM, therapeutic anticoagulation is usually indicated with the expectation that the majority of thrombi will resolve without clinical evidence of systemic embolism. Additional therapeutic intervention is rarely needed.

Role of transesophageal echocardiography in the evaluation of patients with retinal artery occlusion

OBJECTIVE

To evaluate the role of transesophageal echocardiography (TEE) in detecting cardiac and thoracic aortic sources of retinal emboli.

DESIGN

Retrospective observational case series.

PARTICIPANTS

The study population consisted of 18 patients who were initially seen with retinal artery occlusion (7 central, 11 branch) and underwent TEE as part of the systemic evaluation.

INTERVENTION

All patients underwent TEE, consisting of complete two-dimensional and Doppler color flow examinations. TEE was done immediately after transthoracic echo (TTE) examination. The medical records were reviewed.

MAIN OUTCOME MEASURE

Detection of a possible cardiac or thoracic aortic source of retinal embolus.

RESULTS

Cardiac or thoracic aortic pathologic conditions, which were a possible source of the retinal emboli, were detected by TEE in 13 of the 18 patients (72%). They included aortic arch atheroma (n = 7), mitral annulus calcification (n = 4), left atrial appendage thrombus (n = 2), valvular abnormalities (n = 5), left atrial smoke (n = 3), and patent foramen ovale (n = 3). In 11 patients (61%), at least one cardiac or aortic source of emboli detected by TEE was missed by TTE. Significant carotid artery disease (>or=40% stenosis) was present in 3 of 16 patients (17%).

CONCLUSIONS

TEE is a potentially useful modality for detecting possible sources of retinal artery emboli and may be considered as an adjunct to the routine evaluation of affected patients.

Anticoagulation in Congestive Cardiomyopathy: Steps Toward Defining the Great Unknown

It is generally agreed that congestive cardiomyopathy predisposes to the formation of cardiac thrombus and in turn systemic thromboembolism. Several uncontrolled studies have confirmed this association and have prompted wide-scale recommendations for long-term anticoagulation in these patients. Clinical studies have also attempted to identify patients at high risk for embolic events. The presence of cardiac thrombus, its topographic characteristics, the severity of left ventricular dysfunction, and decreased apical flow velocities may each represent markers of increased risk.Driven by the lack of definitive data addressing this issue, several pleas from the medical community have come forth for a large, randomized controlled trial of anticoagulation in congestive cardiomyopathy. Accordingly, a multicenter trial comparing aspirin, warfarin, or placebo as prophylaxis against thromboembolism has been proposed and if conducted will provide valuable information regarding the management of patients with congestive cardiomyopathy.

Initial clinical experience of real-time three-dimensional echocardiography in patients with ischemic and idiopathic dilated cardiomyopathy

The geometry of the left ventricle in patients with cardiomyopathy is often sub-optimal for 2-dimensional ultrasound when assessing left ventricular (LV) function and localized abnormalities such as a ventricular aneurysm. The aim of this study was to report the initial experience of real-time 3-D echocardiography for evaluating patients with cardiomyopathy. A total of 34 patients were evaluated with the real-time 3D method in the operating room (n = 15) and in the echocardiographic laboratory (n = 19). Thirteen of 28 patients with cardiomyopathy and 6 other subjects with normal LV function were evaluated by both real-time 3-D echocardiography and magnetic resonance imaging (MRI) for obtaining LV volumes and ejection fractions for comparison. There were close relations and agreements for LV volumes (r = 0.98, p <0.0001, mean difference = -15 +/- 81 ml) and ejection fractions (r = 0.97, p <0.0001, mean difference = 0.001 +/- 0.04) between the real-time 3D method and MRI when 3 cardiomyopathy cases with marked LV dilatation (LV end-diastolic volume >450 ml by MRI) were excluded. In these 3 patients, 3D echocardiography significantly underestimated the LV volumes due to difficulties with imaging the entire LV in a 60 degrees x 60 degrees pyramidal volume. The new real-time 3D echocardiography is feasible in patients with cardiomyopathy and may provide a faster and lower cost alternative to MRI for evaluating cardiac function in patients.

Echocardiographic Recognition of Left Ventricular Mural Thrombus

Left ventricular (LV) mural thrombus is a well recognized complication of acute myocardial infarction. In survivors of infarction, its incidence is influenced by the location and magnitude of infarction: it occurs often in patients with large anterior Q wave infarctions, particularly in the presence of LV apical akinesis or dyskinesis. Although radionuclide imaging with indium-111-labeled platelets, computed tomography, and magnetic resonance imaging may be used to identify LV mural thrombus, two-dimensional echocardiography is the technique of choice for assessing its presence, shape, and size, and recent technical advances in echocardiographic methodology, such as high-frequency, short-focal-length transducers, have improved the echocardiographic assessment of LV mural thrombus. In the patient in whom a mural thrombus is identified, acute and chronic anticoagulation (with heparin and warfarin, respectively) is indicated: first, to prevent further thrombus formation and, second, to reduce the incidence of systemic embolization.

Role of echocardiography in systemic arterial embolism. A review with recommendations

The ability of echocardiography to diagnose sources of embolism and the role of the examination in the prediction of thromboembolism are reviewed. In addition, the yield of transthoracic (TTE) and transoesophageal echocardiography (TEE) is analysed in patients with suspected embolism and guidelines are proposed for performing echocardiography in this setting. In general, echocardiography is reliable for diagnosing sources of embolism and this applies in particular to TEE in the case of atrial, valvular, and aortic abnormalities. However, the method is useful for predicting embolism in a few cases only. There is a substantial risk in the event of mobile or protruding thrombi, but screening for these and other markers of thromboembolism seems to be unproductive in most groups of risk patients. Yet, in the presence of atrial fibrillation, echocardiography may be helpful in defining patients with an otherwise normal heart and low risk of embolism--and in defining the relatively rare patient with a clinically low-risk profile but moderate-to-severe left ventricular systolic dysfunction and a high risk of embolism. TEE-guided conversion of atrial fibrillation without weeks of preceding anticoagulation may prove useful, after further investigation. The risk of embolism in relation to the size and mobility of valvular vegetations has remained controversial. In patients with suspected recent embolism, TTE results in less than 5% new therapeutic consequences. In those with a normal TTE, the yield of TEE seems to be equally low. We therefore recommend a selective strategy: TTE and TEE can be omitted when a cardiac source of embolism appears from the clinical setting and in most patients with an obvious predisposition to cerebrovascular disease. However, in the latter cases TTE should be performed if indicated by the clinical situation, e.g. in the presence of fever and murmur. TTE is also recommended when there are no obvious markers of primary vascular disease. To preclude very rare sources of embolism (e.g. atrial thrombi despite sinus rhythm), supplementary TEE is recommended in younger patients in whom primary vascular disease is very unlikely. The diagnosis by TEE of common conditions such as atrial septal aneurysms and patent foramen ovale cannot, however, be taken as proof of the mechanism of a systemic arterial occlusive event; thus it is difficult to change therapy on the basis of such diagnoses.

Role of transesophageal echocardiography in the management of thromboembolic stroke

Cardiac causes of stroke account for approximately 20% of strokes occurring in the United States. Transthoracic echocardiography (TTE) remains the cornerstone of non-invasive cardiac imaging, but transesophageal echocardiography (TEE) is superior for identifying potential cardiac sources of emboli, including left atrial thrombi, valvular vegetations, thoracic aortic plaque, patent foramen ovale, and spontaneous left atrial echocardiographic contrast. The diagnostic yield of TEE for potential cardiac causes of thromboembolism exceeds 50%. The impact of TEE on the clinical management of this group, however, remains undefined for most TEE-specific diagnoses. Thus, routine use of TEE in these patients has been questioned. The diagnostic yield is highest if the clinical history/physical examination suggests a cardiac source. However, the clinical scenario often dictates patient management, and TEE data are used to "validate" the clinical impression. Data from large, prospective, randomized (aspirin/warfarin) studies, in which TEE data are obtained from patients with suspected cardiac thromboembolism, are needed. If specific TEE diagnoses can be identified in which defined therapies are beneficial, "source of embolism" will continue to be the most common indication for TEE referral. In this paradigm, TEE (without initial TTE) will probably become a more direct diagnostic pathway. However, if these studies demonstrate that all patients with suspected cardiac source benefit from one (or no) therapy, independent of TEE data, referrals for TEE will decline. Results of ongoing randomized trials to evaluate the efficacy of TEE in patients with cryptogenic stroke or transient ischemic attack are awaited.

Anomalously placed papillary muscle masquerading as a left ventricular apical mass

A 63-year-old man was seen with a history of nonfluent dysphasia and headaches. His blood tested positive for anticardiolipin antibodies. Transthoracic echocardiography showed a mass in the left ventricular apex. The transgastric five-chamber view identified this mass as an anomalously placed papillary muscle. In the presence of an apical mass, if the transthoracic echocardiogram is equivocal, a transesophageal echocardiogram, using the transgastric five-chamber view may be helpful in making the correct diagnosis.

Stress echocardiography using adenosine combined with nitroglycerin-dobutamine in the detection of viable myocardium in patients with previous myocardial infarction

The aim of this study was to assess the value of adenosine (A) and the combination of nitroglycerin (N) with dobutamine (D) stress echocardiography (SE) in the identification of viable myocardium. The clinical and electrocardiographic (ECG) effects of both tests were also evaluated. Fifty-two coronary artery disease patients, aged 56.4 +/- 8 years, with left ventricular dysfunction due to a previous myocardial infarction (mean ejection fraction: 49 +/- 8%) were included in the study. Cardiac catheterization was performed in all patients before A (140 micrograms/kg/minute for five minutes) and the combination of N with D (5-10 micrograms/kg/minute) stress echocardiography. On the echocardiogram, the left ventricle was divided into 16 segments and wall motion was graded semiquantitatively from 1 (normal) to 4 (dyskinesia). The echocardiographic index was also estimated. A segment was considered viable during A infusion when resting asynergy showed deterioration of one grade or more. In contrast, segmental viability was considered to be present during the combination of N with D infusion when resting asynergy showed improvement of one grade or more. A thallium 201 single photon emission computed tomography (SPECT) with reinjection was performed as reference standard for the identification of viable myocardium. Stress echocardiography during infusion of A was associated with short-duration angina attacks in 3 (5.8%) patients and transient complete atrioventricular (AV) block in 1 (1.9%), whereas during the combination of N with D infusion, 6 (11.5%) patients experienced ventricular bigeminy lasting for a short period. ST segment elevation greater than 1 mm was recorded in those leads having a Q wave, in 19 (36.5%) patients. In 10 of these 19 (52.6%), viable myocardium was present in SPECT, as it was in 33 patients (63.5%) having no ST segment elevation (P = NS). Of a total of 832 segments that were graded during A-SE, 276 exhibited resting asynergy and the remaining 556 had normal motion and thickening at rest. The echocardiographic index during A infusion increased from 1.52 +/- 0.22 to 1.71 +/- 0.24 (P < 0.001), whereas during D and N infusion it decreased from 1.53 +/- 0.31 to 1.30 +/- 0.42 (P < 0.001). With SPECT considered as the gold standard for the identification of viable myocardium, sensitivity, specificity, and positive and negative predictive values of A-SE in detecting viable myocardium were 54%, 86%, 65% and 80%, respectively. The respective values for the combination of nitroglycerin with D-SE were 91%, 89%, 78%, and 96%, respectively. Stress echocardiography during A, and the combination of N with D, constitute safe methods in the identification of viable myocardium. The detection of ST segment elevation in the ECG leads with a Q wave during the combined infusion of nitroglycerin and dobutamine is not related to the presence of viable myocardial tissue. The A-SE provide moderate diagnostic accuracy, while the combination of N with D during SE is much superior in detecting viable myocardium.

Transesophageal echocardiographic assessment of embolic sources: intracardiac and extracardiac masses and aortic degenerative disease

The increased sensitivity of transesophageal echocardiography (TEE) makes it complementary and, in many cases, superior to transthoracic echocardiography in the detection of various sources of embolism. These sources include intracardiac thrombus, tumors, spontaneous echocardiographic contrast, and others. TEE is also helpful as an adjunctive test for the diagnosis of pulmonary embolisms.