Photorealistic imaging of left atrial appendage occlusion/exclusion.

Recent improvements in 3D TEE post processing rendering techniques referred to as TrueVue (Philips Medical Systems, Andover, MA, USA). It allows for novel photorealistic imaging of cardiac structures including left atrial appendage (LAA) and its closure devices. Here we present TrueVue images of the LAA prior to and after LAA exclusion/occlusion using various percutaneous and surgical techniques. TrueVue may improve delineation of LAA anatomy prior to occlusion as well as visualization of occluder device position within the LAA.

Left Atrial Occlusion Device Implantation: the Role of the Echocardiographer.

PURPOSE OF REVIEW: Atrial fibrillation is the most common arrhythmia worldwide and is a major risk factor for embolic stroke. For patients with atrial fibrillation who are unable to tolerate systemic anticoagulation, left atrial appendage (LAA) occlusion has been shown to mitigate stroke risk. In this article, we describe the vital role of the echocardiographer in intraprocedural guidance of percutaneous LAA occlusion procedures as well as in the pre- and post-procedure assessment of these patients. RECENT FINDINGS: A few percutaneously delivered devices for LAA exclusion from the systemic circulation are available in contemporary practice. These devices employ an either exclusive endocardial LAA occlusion approach, such as the Watchman (Boston Scientific, Maple Grove, MN) and Amulet (St. Jude Medical, Minneapolis, MN), or both an endocardial and pericardial (epicardial) approach such as the Lariat procedure (SentreHEART, Palo Alto, CA). Two- and three-dimension transesophageal echocardiography is critical for patient selection, procedure planning, procedural guidance, and ensuring satisfactory immediate as well as long-term LAA occlusion/exclusion efficacy. This review will provide an overview of the role of the echocardiographer in all aspects of LAA occlusion/exclusion procedures for the most commonly used commercially available devices in current practice.

Advanced Imaging Techniques for Mitral Regurgitation.

Mitral regurgitation (MR) is one of the most commonly encountered valvular lesions in clinical practice. MR can be either primary (degenerative) or secondary (functional) depending on the etiology of MR and the pathology of the mitral valve (MV). Echocardiography is the primary diagnostic tool for MR and is key in determining this etiology as well as MR severity. While clinicians usually turn to 2 Dimensional echocardiography as first-line imaging, 3 Dimensional echocardiography (3DE) has continually shown to be superior in terms of describing MV anatomy and pathology. This review article elaborates on 3DE techniques, modalities, and advances in software. Furthermore, the article demonstrates how 3DE has reformed MR evaluation and has played a vital role in determining patient management.

Multimodality imaging of scimitar syndrome in adults: A report of four cases.

Partial anomalous pulmonary venous return (PAPVR) comprises a group of congenital cardiovascular anomalies associated with pulmonary venous flow directly or indirectly into the right atrium. Scimitar syndrome is a variant of PAPVR in which the right lung is drained by right pulmonary veins connected anomalously to the inferior vena cava. Surgery is the definitive treatment for scimitar syndrome. However, it is not always necessary as many patients are asymptomatic, have small left-to-right shunts, and enjoy a normal life expectancy without surgery. We report multimodality imaging in four adults with scimitar syndrome and the implications for management of this rare syndrome.

Left Atrial Appendage Occlusion/Exclusion: Procedural Image Guidance with Transesophageal Echocardiography.

Atrial fibrillation is the most common arrhythmia worldwide and is a major risk factor for embolic stroke. In this article, the authors describe the crucial role of two- and three-dimensional transesophageal echocardiography in the pre- and postprocedural assessment and intraprocedural guidance of percutaneous left atrial appendage (LAA) occlusion procedures. Although recent advances have been made in the field of systemic anticoagulation with the novel oral anticoagulants, these medications come with a significant risk for bleeding and are contraindicated in many patients. Because thromboembolism in atrial fibrillation typically arises from thrombi originating in the LAA, surgical and percutaneous LAA exclusion/occlusion techniques have been devised as alternatives to systemic anticoagulation. Currently, surgical LAA exclusion is typically performed as an adjunct to other cardiac surgical procedures, which limits the number of eligible patients. Recently, several percutaneously delivered devices for LAA exclusion from the systemic circulation have been developed, some of which have been shown in clinical trials to reduce the risk for thromboembolism. These devices use an either purely endocardial LAA occlusion approach, such as the Watchman and Amulet procedures, or both an endocardial and a pericardial (epicardial) approach, such as the Lariat procedure. In the Watchman and Amulet procedures, a transseptally delivered structure composed of nitinol is placed in the LAA orifice, thereby excluding the LAA from the systemic circulation. In the Lariat procedure, a magnet link is created between a transseptally delivered endocardial wire and epicardially delivered pericardial wire, followed by epicardial suture ligation of the LAA.

3D transesophageal echocardiography and radiography of mitral valve prostheses and repairs.

This paper provides a comprehensive overview of 3D transesophageal echocardiography still images and movies of mechanical mitral valves, mitral bioprostheses, and mitral valve repairs. Alongside these visual descriptions, the historical overview of surgical and percutaneous mitral valve intervention is described with the special emphasis on the incremental value of 3D transesophageal echocardiography (3DTEE). For each mitral valve intervention, 2D echocardiography, chest x-ray, and fluoroscopy images corresponding to 3DTEE are given. In addition, key references on echocardiographic imaging of individual valves and procedures are enumerated in accompanying figures and tables.

Aortic root thrombus complicated by left main coronary artery occlusion visualized by 3D echocardiography in a patient with continuous-flow left ventricular assist device.

Aortic root thrombus is an uncommon complication of continuous-flow left ventricular assist devices (LVAD). We present the case of a 71-year-old man with ischemic cardiomyopathy who underwent destination therapy HeartMate II LVAD placement. Eighteen months later, he presented with a cerebrovascular accident followed by myocardial infarction. Transesophageal echocardiography revealed an aortic root thrombus spanning the left and noncoronary cusps and obliterating the left main coronary artery. We discuss the incidence, risk factors, and management of aortic root thrombus in LVAD patients. To our knowledge, this is the first report of three-dimensional echocardiography used to characterize an LVAD-associated aortic root thrombus.

Ankle-Brachial Index Testing at the Time of Stress Testing in Patients Without Known Atherosclerosis.

BACKGROUND: Individuals referred for stress testing to identify coronary artery disease may have nonobstructive atherosclerosis, which is not detected by stress tests. Identification of increased risk despite a negative stress test could inform prevention efforts. Abnormal ankle-brachial index (ABI) is associated with increased cardiovascular risk. HYPOTHESIS: Routine ABI testing in the stress laboratory will identify unrecognized peripheral arterial disease in some patients. METHODS: Participants referred for stress testing without known history of atherosclerotic disease underwent ABI testing (n = 451). Ankle-brachial index was assessed via simultaneous arm and leg pressure using standard measurement, automated blood-pressure cuffs at rest. Ankle-brachial index was measured after exercise in 296 patients and 30 healthy controls. Abnormal postexercise ABI was defined as a >20% drop in ABI or fall in ankle pressure by >30 mm Hg. RESULTS: Overall, 2.0% of participants had resting ABI ≤0.90, 3.1% had ABI ≥1.40, and 5.5% had borderline ABI. No patient with abnormal or borderline ABI had an abnormal stress test. Participants who met peripheral arterial disease screening criteria (age ≥65 or 50-64 with diabetes or smoking) tended toward greater frequency of low ABI (2.9% vs 1.0%; P = 0.06) and were more likely to have borderline ABI (0.91 to 0.99; 7.8% vs 2.9%; P = 0.006). Postexercise ABI was abnormal in 29.4% of patients and 30.0% of controls (P not significant). CONCLUSIONS: Ankle-brachial index screening at rest just before stress testing detected low ABI in 2.0% of participants, all of whom had negative stress tests.

Carotid stenosis: from diagnosis to management, where do we stand?

Carotid atherosclerosis is implicated in 20-30 % of strokes. However, the annual risk of stroke in patients with asymptomatic carotid stenosis is less than 5 %. Symptomatic carotid stenosis poses a greater risk for recurrent stroke with estimates as high as 15 % per year. This paper aims to raise awareness of populations at risk for carotid stenosis, the role of carotid screening and the sensitivity and specificity of various diagnostic modalities. The results of previous trials that support current guidelines for management of symptomatic and asymptomatic carotid stenosis will also be reviewed.

Usefulness of comprehensive cardiothoracic computed tomography in the evaluation of acute undifferentiated chest discomfort in the emergency department (CAPTURE).

Newer cardiac computed tomographic (CT) technology has permitted comprehensive cardiothoracic evaluations for coronary artery disease, pulmonary embolism, and aortic dissection within a single breath hold, independent of the heart rate. We conducted a randomized diagnostic trial to compare the efficiency of a comprehensive cardiothoracic CT examination in the evaluation of patients presenting to the emergency department with undifferentiated acute chest discomfort or dyspnea. We randomized the emergency department patients clinically scheduled to undergo a dedicated CT protocol to assess coronary artery disease, pulmonary embolism, or aortic dissection to either the planned dedicated CT protocol or a comprehensive cardiothoracic CT protocol. All CT examinations were performed using a 64-slice dual source CT scanner. The CT results were immediately communicated to the emergency department providers, who directed further management at their discretion. The subjects were then followed for the remainder of their hospitalization and for 30 days after hospitalization. Overall, 59 patients (mean age 51.2 ± 11.4 years, 72.9% men) were randomized to either dedicated (n = 30) or comprehensive (n = 29) CT scanning. No significant difference was found in the median length of stay (7.6 vs 8.2 hours, p = 0.79), rate of hospital discharge without additional imaging (70% vs 69%, p = 0.99), median interval to exclusion of an acute event (5.2 vs 6.5 hours, p = 0.64), costs of care (p = 0.16), or the number of revisits (p = 0.13) between the dedicated and comprehensive arms, respectively. In addition, radiation exposure (11.3 mSv vs 12.8 mSv, p = 0.16) and the frequency of incidental findings requiring follow-up (24.1% vs 33.3%, p = 0.57) were similar between the 2 arms. Comprehensive cardiothoracic CT scanning was feasible, with a similar diagnostic yield to dedicated protocols. However, it did not reduce the length of stay, rate of subsequent testing, or costs. In conclusion, although this "triple rule out" protocol might be helpful in the evaluation of select patients, these findings suggest that it should not be used routinely with the expectation that it will improve efficiency or reduce resource use.

Frequency of severe renal artery stenosis in patients with severe thoracic aortic plaque.

Atherosclerotic renal artery stenosis (RAS) is an underdiagnosed disorder and a treatable etiology of hypertension and renal insufficiency. All patients were referred for a transesophageal echocardiogram for various indications. Abdominal ultrasound was performed in 69 patients, 43 with severe thoracic aortic plaque (> or =4 mm) and 26 controls with no or mild plaque (< or =2 mm). Severe RAS (> or =60%) was defined as flow velocity > or =1.8 m/s and a renal:aortic ratio of > or =3.5. There were 8 cases of RAS (all severe) in the 43 patients with severe aortic plaque (19% vs 0% of controls; p = 0.02). Severe plaque (p = 0.02) and hypertension (p = 0.03) were correlated with RAS. On multivariate analysis, severe plaque (p = 0.017) and hypertension (p = 0.002) remained independently correlated with RAS. In a paired analysis, matched for age and gender (McNemar), severe plaque was significantly associated with RAS (p = 0.008). Severe thoracic aortic plaque is strongly associated with RAS, which is found in 19% of patients with severe plaque. Patients found to have severe aortic plaque on transesophageal echocardiography should be screened for RAS.