Introduction to Transesophageal Echocardiography Nakeisha L. Pierre, M.D Tulane Department Anesthesiology Look Familiar?! IVC or SVC ? Basic Principles of Ultrasound and Doppler Echocardiography creates images of the heart from reflected sound waves The ultrasound transducer records the time delay and amplitude for each returning transmission Speed in a medium is constant, so only the distance of the structure from the probe alters the time to receive the reflected wave Timing the interval between transmissions and the time it takes to receive reflected signals allows the ultrasound system to precisely calculate the location of structures and construct images Basic Principles of Ultrasound and Doppler 2-D echo is unable to visualize blood flow.. It’s presented as just black on the display Doppler ultrasonography overcomes this limitation The Doppler system determines the velocity of blood flow by assessing the change in frequency of the ultrasound reflected from moving red blood cells Directing the ultrasound at the flow of blood and listening for those changes in frequency allows Doppler echo to determine direction and speed of blood flow Basic Principles of Ultrasound and Doppler Frequency (cycles/s) is a property exclusive to the echo transducer/probe ( 210Hz) Frequency determines signal strength and imaging resolution Signal strength Lower freq – stronger signal Disadvantage is decreased image resolution Imaging resolution Higher freq – better image resolution Disadvantage – decreased penetration/weaker signal Doppler Flow Category I Indications for Intra-Operative TEE Acute, persistent life-threatening disturbances Valve repair – particularly mitral valve Aortic valve resuspension in dissection or aneurysm sx Congenital heart surgery Obstructive cardiomyopathy Endocarditis Thoracic Aortic Aneurysm Pericardial Window *conditions for which there is evidence and/or general agreement that a given procedure is useful and effective* Category II Indications for Intra-Operative TEE Increased risk for MI or unstable hemodynamics Valve replacement Myocardial aneurysm repair Cardiac assist devices Myocardial/intracardiac mass rsxn Foreign body detection or removal Pulmonary endareterctomy Suspected cardiac trauma Aortic atheromatous disease Pericardial surgery Cardiac or pulmonary transplantation *Conditions for which there is conflicting evidence and/or divergence of opinion about the usefulness or efficacy of procedure/treatment* Contraindications to Intra-Operative TEE Esophageal disease – stricture, diverticuli, varices, tumor Prior esophageal or stomach surgery Perforated viscus Difficulty passing the TEE probe Anticoagulation Thrombocytopenia Facial or airway trauma Anatomical Relationships The esophagus provides an excellent window for visualizing detailed echocardiographic images secondary to its close proximity to the heart The esophagus extends from the posterior pharynx through the mediastinum where it courses behind the trachea left main bronchus and continues inferiorly where it becomes immediately adjacent to LA and LV Esophagus Comprehensive TEE Exam 20 views recommended by ASE task force Goal during any exam is to visualize structure and function of heart and not necessarily get all 20 views Comprehensive TEE Exam Comprehensive TEE Exam Views designated by Echo window Main anatomic structure Upper esophageal (20-25cm) Mid esophageal (30-40cm) Transgastric (40-45cm) Deep transgastric (45-50cm) AV RV Imaging plane Short axis/SAX Long axis/LAX Comprehensive TEE Exam At a multiplane angle of 0 degrees (the horizontal or transverse plane), with the imaging plane directed anteriorly from the esophagus through the heart, the patient’s right side appears in the left of the display. Rotating the multiplane angle forward to 90 degrees (vertical or sagittal plane) moves the left side of the display inferiorly, toward the supine patient’s feet. Rotating the multiplane angle to 180 degrees places the patient’s left side to left of the display, the mirror image of 0 degrees. Orientation of the Heart Comprehensive TEE Exam Advance Withdraw Retroflex Flex to Left Flex to Right Anteflex Mid.Ant line rotation ME Asc Aortic SAX Angle: 10-30 degrees Diagnostic Uses: aortic atherosclerosis, aortic dissection/ dilation, PA pathology (emboli) ME Asc Aortic LAX Angle: 100 degrees Diagnostic Uses: aortic atherosclerosis, aortic dissection, asc aortic dilation Right Pulmonary A. Ascending Aorta ME AV SAX Angle:25-45 degrees Diagnostic Uses: aortic stenosis, valve morphology NCC LCC RCC ME RV Inflow-Outflow Angle: 50-70 degrees Diagnostic Uses: PV disease, PA pathology, RVOT pathology ME Bicaval Angle: 105-120 degrees +/- rightward rotation Diagnostic Uses: right atrial free wall, SVC, interatrial septum, IVC Positive Bubble Study ME AV LAX Angle: 115-130degrees Diagnostic Uses: AV pathology, aorta pathology, LVOT pathology ME four chamber Angle:0-10 degrees Diagnostic Uses: ASD, chamber enlargement/dysfxn, LV regional wall motion abnml,mitral dz, tricsupid dz, intracardiac Lateral Wall Septal Wall Mitral Valve ME Mitral Commissural Angle: 60-75 degrees Diagnostic Uses: localization of mitral valve pathology P3 P1 A2 ME two chamber Angle:80-100degrees Diagnostic Uses: left atrial appendage mass/thrombus,LV apex pathology LV systolic fxn/RWM Coronary Sinus A3A2A1 P3 ME LAX Angle: 110-130 degrees Diagnostic Uses: MV pathology, LVOT pathology, LV RWM abnml A2 P2 Anteroseptal Wall Posterior Wall TG Basal SAX Angle: 0 degrees +/- anteflexion Diagnostic Uses: LV systolic dysfunction, MV pathology Posterior Leaflet Anterior Leaflet TG Mid(pap) SAX Angle:0 degrees w/ anteflexion Diagnostic Uses: hemodynamic instability, LV dilation/hypertrophy, LV systolic function, LV RWM Transgastric Two Chamber Angle: 90 degrees Diagnostic Uses: LV systolic dysfunction (ant/inf walls) Inferior Wall Inferior (ant) Anterior Anterior Wall TG LAX Angle: 110-130 degrees +/- left rotation Diagnostic Uses: LV systolic dysfunction, doppler AV AV TG RV Inflow Angle: 110-130 degrees + right rotation Diagnostic Uses: RV systolic fxn, tricuspid pathology Tricuspid Valve RV RA Deep TG LAX Angle: 0 degrees + anteflexion Diagnostic Uses: AV pathology, LVOT pathology, doppler AV Desc Aortic SAX Angle: 0 degrees Diagnostic Uses: aortic atherosclerosis, aortic dissection Desc Aortic LAX Angle: 90 degrees Diagnostic Uses: aortic atherosclerosis, aortic dissection, IABP placement UE Aortic Arch LAX Angle: 0 degrees + rightward rotation Diagnostic Uses: aortic atherosclerosis/dissection, measure distal asc aorta Aortic Arch UE Aortic Arch SAX Angle: 90 degrees Diagnostic Uses: aortic atherosclerosis/dissection Pulmonary Artery Pulmonic Valve Aortic Arch References Fleisher, et al. Intraoperative TEE. Philadelphia: Elsevier, 2008 Perrino, et al. A Practical Approach to Transesophageal Echo. Philadelphia: Lippincott, 2008 Peak. Nuts and Bolts of Ultrasound Physics. Houston, 2006 Riedel. Guidelines for Performing a Comprehensive Intraoperative Multiplane TEE exam. Houston, 2006 Shanewise, et al. ASE/SCA Intraoperative TEE Guidelines. Anethes Analg 1999:89:870-84 Sidebotham. Practical Perioperative TEE. London: Butterworth Heinmann, 2003