Faculty Bibliography

Lipomatous atrial septal hypertrophy (LASH) is a histologically benign cardiac lesion characterized by excessive fat deposition in the region of the interatrial septum that spares the fossa ovalis. The etiology of LASH remains unclear, though it may be associated with advanced age and obesity. Because of the sparing of the fossa ovalis, LASH has a pathognomonic dumbbell shape. LASH may be mistaken for various tumors of the interatrial septum. Histologically, LASH is composed of both mature and brown (fetal) adipose tissue, but the role of brown adipose tissue remains unclear. In interventional procedures requiring access to the left atrium, LASH may interfere with transseptal puncture, as traversing the thickened area can reduce the maneuverability of catheters and devices. This may cause the needle to enter the epicardial space, causing dangerous pericardial effusions. LASH was once considered a contraindication to percutaneous device closure of atrial septal defects because of an associated increased risk for incorrect device deployment. However, careful attention to preprocedural imaging and procedural intracardiac echocardiography enable interventional cardiologists to perform procedures in patients with LASH without serious complications. In this review article, the authors describe anatomic and functional aspects of LASH, with emphasis on their roles in percutaneous interventions.

Transcatheter aortic valve replacement is increasingly performed as a minimally invasive treatment option for aortic valve disease. The typical anesthetic management for this procedure was traditionally similar to surgical aortic valve replacement and involved general anesthesia and transesophageal echocardiography. In this review, we discuss the technological advances in transcatheter valve systems that have improved outcomes and allow for use of sedation instead of general anesthesia. We describe an anesthetic protocol that avoids general anesthesia and utilizes transthoracic echocardiography for procedural guidance.

Contraindications to transesophageal echocardiography (TEE) include various esophageal pathologies, but compression of the esophagus by vertebral osteophytes is not listed in the current American Society of Echocardiography guidelines. We report a case of diffuse idiopathic skeletal hyperostosis (DISH) in an 81-year-old man who had incidentally been found to have extrinsic esophageal compression by cervical osteophytes prior to a proposed TEE. The incidence of esophageal perforation in patients with DISH and vertebral osteophytes is not well documented. We believe these patients are at increased risk of esophageal perforation during TEE, and thus, TEE may be relatively contraindicated in patients with DISH.

Echocardiography is the preferred initial imaging method for assessment of cardiac masses. Cardiac magnetic resonance (CMR) imaging, with its excellent tissue characterization and wide field of view, may provide additional unique information. We evaluated the predictive value of echocardiography and CMR imaging parameters to identify tumors and malignancy and to provide histopathologic diagnosis of cardiac masses. Fifty patients who underwent CMR evaluation of a cardiac mass with subsequent histopathologic diagnosis were identified. Echocardiography was available in 44 of 50 cases (88%). Echocardiographic and CMR characteristics were evaluated for predictive value in distinguishing tumor versus nontumor and malignant versus nonmalignant lesions using histopathology as the gold standard. The Wilcoxon rank-sum test was used to compare the 2 imaging methods' ability to provide the correct histopathologic diagnosis. Parameters associated with tumor included location outside the right atrium, T2 hyperintensity, and contrast enhancement. Parameters associated with malignancy included location outside the cardiac chambers, nonmobility, pericardial effusion, myocardial invasion, and contrast enhancement. CMR identified 6 masses missed on transthoracic echocardiography (4 of which were outside the heart) and provided significantly more correct histopathologic diagnoses compared to echocardiography (77% vs 43%, p <0.0001). In conclusion, CMR offers the advantage of identifying paracardiac masses and providing crucial information on histopathology of cardiac masses.

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 /=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.

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.

Congenital absence of left atrial appendage (LAA) is an extremely rare condition and its physiological consequences are unknown. We present two cases of incidental finding of a congenitally absent LAA in a 79-year-old male who presented for routine transesophageal echocardiogram (TEE) to rule out intracardiac thrombus prior to placement of biventricular implantable cardioverter-defibrillator and a 54-year old female who presented for TEE prior to radiofrequency ablation of atrial fibrillation. Characterization of patients with such an absence is important because congenitally absent LAA may be confused with flush thrombotic occlusion of the appendage. There are very few published reports of congenital absence of LAA. To our knowledge, our report is the first to demonstrate the congenital absence of LAA by 3D transesophageal echocardiography.