Transesophageal Echocardiography

Transesophageal Echocardiography

Khandheria Bijoy K
US Cardiology 2006
Published: November 2005
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Cardiovascular ultrasound is an established imaging modality in the practice of cardiovascular disease (CVD), whether this is provided by a CV specialist or health professionals with training in internal medicine. Transthoracic imaging wherein the transducer is placed on the chest wall has some limitations. These include inadequate quality of images resulting in poor information—approximately 5% of all patients undergoing transthoracic echocardiography may be the subject of poor quality images. Inability to view structures such as the arch of the aorta, descending thoracic aorta, and left atrial image, due to the location of these structures within the thorax, has led to innovations such as transesophageal ecocardiogram (ECG) (TEE) and intracardiac ECG. Over the last three decades, TEE has evolved as an essential ultrasonographic technique for a rapid tomographic evaluation of the CV system. Imaging from the confines of the gastroesophageal track reduces signal attenuation and permits use of higher ultrasound frequencies, thereby providing superb spatial resolution.

Although interpretation of the structural and hemodynamic information from TEE needs additional training, the technique has been integrated in the standard practice of CV ultrasound (CV), particularly those that demand quick medical decision-making.The role of TEE has become established beyond the confines of the CV ultrasound imaging and hemodynamic laboratory, and is being used with increasing frequency in the operating room (OR), with percutaneous procedures such as closure of defects within the heart, percutaneous implantation of valves, and surgical procedures being performed in the catheterization or the electrophysiologic laboratory.An increasing number of anesthetists, surgeons. and intensivists now use it routinely for monitoring and guiding operative procedures, interventions, and managing critically ill patients. This article briefly reviews the indications and emerging trends in the application of TEE.

TEE for recording continuous wave Doppler velocities of cardiac flow was first described by Side and Josling in 1971.1 Subsequently, the first transesophageal M-mode ECG was reported by Frazin et al. in 1976,2 while in 1977, Hisanaga et al. illustrated the use of cross-sectional realtime imaging using a scanning device that consisted of a rotating single element in an oil-filled balloon mounted at the tip of the gastroscope.3 The initial acceptance of TEE was offset by the logistic difficulties of introducing rigid endoscopes. The ensuing technological developments that facilitated the transition of TEE to its present clinical status included the introduction of flexible endoscope, miniaturization and improvements in transducer designs, serial improvement in scanning capabilities from monoplane, biplane to multiplane views, and the addition of spectral and color Doppler imaging.TEE is currently used either as complementary or stand-alone treatment to a routine transthoracic ECG in approximately 5% to 10% of patients being referred for CV ultrasound imaging test.

Instrumentation, Procedure, and Complications
TEE can be performed as an out-patient or in-patient procedure. Fasting, as recommended for conscious sedation, appropriate intravenous (IV) access, careful history-taking to rule out the presence of laryngeal or gastroesophageal diseases, and removal of dentures are prerequisites. Absolute contraindications to TEE include esophageal stricture, diverticulum, tumor, and recent esophageal or gastric surgery. Topical spray, IV sedation, a drying agent to minimize oral secretion, and use of appropriate lubrication are helpful. Once in the esophagus, the transducer should be gently guided— the operator should never force this if they encounter resistance.Although the risk of bacterial endocarditis is extremely low and routine antibiotic prophylaxis before TEE is not advocated, it may be considered in high-risk patients such as those with a past history of infective endocarditis.

Although the study needs to examine all the regions of the heart and great vessels, examination can be initially targeted for resolving the primary indication for which TEE is being performed.

Each operator should establish a standard approach to obtaining all of the views when performing this examination.4 The current best practice requires the use of a multiplane TEE transducer. The procedure should only be performed by adequately trained individuals.5 Procedural risks, though low in trained hands, include transient throat pain, laryngospasm, aspiration, hypotension, hypertension, tachycardia,mucosal bleeding, esophageal rupture, and a rare risk of death. Benzocaine topical spray can cause toxic methemoglobinemia.

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References:
  1. Side C D, Gosling R G, “Non-surgical assessment of cardiac function”, Nature (1971);232: pp. 335–336.
  2. Frazin L, Talano J V, Stephanides L, Loeb H S, Kopel L, Gunnar R M, “Esophageal echocardiography”, Circulation (1976);54: pp. 102–108.
  3. Hisanaga K H A, Nagata K,Yoshida S, “A new transesophageal real time two dimensional echocardiographic system using a flexible tube and its clinical application”, Proc. Jpn Soc. Ultrasonics Med. (1977);32: pp. 43–44.
  4. Seward J B, Khandheria B K, Freeman W K et al.,“Multiplane transesophageal echocardiography: image orientation, examination technique, anatomic correlations, and clinical applications”,Mayo Clin. Proc. (1993);68: pp. 523–551.
  5. Pearlman A S, Gardin J M, Martin R P et al., “Guidelines for physician training in transesophageal echocardiography: recommendations of the American Society of Echocardiography Committee for Physician Training in Echocardiography”, J. Am. Soc. Echocardiogr. (1992);5: pp. 187–194.
  6. Vilacosta I, Graupner C, San Roman J A et al., “Risk of embolization after institution of antibiotic therapy for infective endocarditis”, J.Am. Coll. Cardiol. (2002);39: pp. 1,489–1,495.
  7. Bayer A S, Bolger A F, Taubert K A et al., “Diagnosis and management of infective endocarditis and its complications”, Circulation (1998);98: pp. 2,936–2,948.
  8. Heidenreich P A, Masoudi F A, Maini B et al., “Echocardiography in patients with suspected endocarditis: a cost-effectiveness analysis”, Am. J. Med. (1999);107: pp. 198–208.
  9. Khandheria B K, Seward J B, Oh J K et al.,“Value and limitations of transesophageal echocardiography in assessment of mitral valve prostheses”, Circulation (1991);83: pp. 1,956–1,968.
  10. Palazzuoli A, Ricci D, Lenzi C et al.,“Transesophageal echocardiography for identifying potential cardiac sources of embolism in patients with stroke”, Neurol. Sci. (2000);21: pp. 195–202.
  11. Agmon Y, Khandheria B K, Gentile F et al., “Clinical and echocardiographic characteristics of patients with left atrial thrombus and sinus rhythm: experience in 20 643 consecutive transesophageal echocardiographic examinations”, Circulation (2002);105: pp. 27–31.
  12. Leung D Y, Black I W, Cranney G B et al., “Prognostic implications of left atrial spontaneous echo contrast in nonvalvular atrial fibrillation”, J.Am. Coll. Cardiol. (1994);24: pp. 755–762.
  13. Kamp O,Verhorst P M,Welling R C et al.,“Importance of left atrial appendage flow as a predictor of thromboembolic events in patients with atrial fibrillation”, Eur. Heart J. (1999);20: pp. 979–985.
  14. Klein A L, Grimm R A, Murray R D et al., “Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation”, N. Engl. J. Med. (2001);344: pp. 1,411–1,420.
  15. Klein A L, Murray R D, Becker E R et al., “Economic analysis of a transesophageal echocardiography-guided approach to cardioversion of patients with atrial fibrillation: the ACUTE economic data at eight weeks”, J.Am. Coll. Cardiol. (2004);43: pp. 1,217–1,224.
  16. Smith M D, Cassidy J M, Souther S et al.,“Transesophageal echocardiography in the diagnosis of traumatic rupture of the aorta”, N. Engl. J. Med. (1995);332: pp. 356–362.
  17. Keren A, Kim C B, Hu B S et al.,“Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma”, J.Am. Coll. Cardiol. (1996);28: pp. 627–636.
  18. Agmon Y, Khandheria B K, Meissner I et al.,“Relation of coronary artery disease and cerebrovascular disease with atherosclerosis of the thoracic aorta in the general population”, Am. J. Cardiol. (2002);89: pp. 262–267.
  19. Russo A, De Luca M, Vigna C et al., “Central pulmonary artery lesions in chronic obstructive pulmonary disease: A transesophageal echocardiography study”, Circulation (1999);100: pp. 1,808–1,815.
  20. Pascoe R D, Oh J K,Warnes C A et al.,“Diagnosis of sinus venosus atrial septal defect with transesophageal echocardiography”, Circulation (1996);94: pp. 1,049–1,055.
  21. Mas J L, Arquizan C, Lamy C et al., “Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both”, N. Engl. J. Med. (2001);345: pp. 1,740–1,746.
  22. Randolph G R, Hagler D J, Connolly H M et al.,“Intraoperative transesophageal echocardiography during surgery for congenital heart defects”, J.Thorac. Cardiovasc. Surg. (2002);124: pp. 1,176–1,182.
  23. Scalia G M, McCarthy P M, Savage R M et al., “Clinical utility of echocardiography in the management of implantable ventricular assist devices”, J.Am. Soc. Echocardiogr. (2000);13: pp. 754–763.

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