Faculty Bibliography

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.

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.

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.

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 Transfemoral transcatheter aortic valve replacement (TF TAVR) can be performed under general anesthesia (GA) or moderate sedation (MS). Despite observational studies suggesting a shorter length of stay (LOS), shorter procedural time and a similar mortality rate with MS, only 5% of patients undergoing TF TAVR in the United States are done with this type of anesthesia. We reviewed the implementation of a MS for TF TAVR protocol at a single institution with no previous experience with this technique. METHODS Patients with severe obstructive sleep apnea (OSA), likely difficult intubation, inability to tolerate supine position due to musculoskeletal disease, or barriers to communication including altered mental status were performed under GA with intraoperative transesophageal echocardiography. All others received MS with an ilioinguinal nerve block and intraoperative transthoracic echocardiography. The MS for TF TAVR protocol was implemented on October 9th, 2014. The records of patients undergoing TF TAVR 6 months before and after protocol implementation were retrospectively reviewed. RESULTS In the pre protocol group 33 patients underwent TF TAVR under GA and no patients received MS. In the post protocol group, 97 underwent TF TAVR, 81 (83.5%) of which received MS. OSA was the most common reason for GA (N=10, 62.5%). Conversion from MS to GA occurred in 2 cases (2.5%) due to procedural complications, of which 1 resulted in death. All other cases involving MS were tolerated well and there were no anesthesia related complications. Post procedural LOS (3.2 days vs. 5.0 days, p=0.002) and procedure time (144.0 minutes vs. 96.1 minutes, p<0.001) were both significantly shorter in post protocol group. The post protocol group was also significantly less likely to require a skilled nursing facility upon discharge (24.2% vs. 8.2%, p=0.027). In hospital mortality was similar between groups (N=2 6.1% vs. N=3, 3.1%, p=0.601). (Table Presented) CONCLUSIONS The MS for TF TAVR protocol appears safe and can be rapidly implemented at institutions with no previous MS experience. This technique is feasible in the majority of patient undergoing TF TAVR. Post procedural LOS and procedural time are multifactorial, but this data further suggests MS may be beneficial in select patients

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.