Transesophageal Echocardiography Using Cypress-Miniaturized Echocardiogram Unit: Initial Clinical Experience Eyal Herzog, M.D., Danny Pudpud, R.D.C.F., and Farooq A. Chaudhry, M.D. Division of Cardiology, St. Luke’s-Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York Transesophageal echocardiography (TEE) was introduced clinically in the United States in 1987. Recent technologic advances have resulted in the creation of a small portable hand-carried ultrasound (HCU) device that can be easily carried throughout the hospital with greater flexibility for cardiac imaging. These HCU devices have harmonic, color, and spectral Doppler (continuous/pulsed wave). Siemens Medical Solutions USA, Inc. has incorporated a TEE connector, which connects to its Cypress (highly miniaturized echocardiogram unit) and allows the performance of a TEE with this unit, which is mildly heavier than a typical HCU. We describe our initial clinical experience with this unit. The image quality is comparable to routine TEEs, with the advantages of shorter duration, portability, affordable cost, avoiding the use of high-end machine from the echo lab, availability of non-HCU units for other studies, and preventing the need for an echo technician to be involved in the procedure. (ECHOCARDIOGRAPHY, Volume 22, November 2005) transesophageal echocardiography, hand-carried ultrasound, cardiac care unit, Cypress, miniaturized echocardiogram In 1987, transesophageal echocardiography (TEE) was introduced clinically in the United States and altered the diagnostic strategy of cardiovascular imaging.1,2 TEE offers the advantages of better resolution compared to transthoracic images, particularly of posterior structures including the pulmonary veins, left atrium, aorta, and the mitral valve. The image quality is improved because of the decreased distance between the transducer and the structures of interest, imaging at a higher frequency, and the absence of intervening lungs or bone tissue.3 Twenty-six years ago, Roelandt et al.4 published the “ultrasonic cardioscope,” a portable hand-carried ultrasound (HCU) device capable of providing two-dimensional echocardiography.5 Recent technologic advances have resulted in the creation of an HCU the size of a laptop, which can easily be transported throughout the hospital and have enabled carAddress for correspondence and reprint requests: Eyal Herzog, M.D., Director, Cardiac Care Unit, St. Luke’sRoosevelt Hospital, Columbia University College of Physicians and Surgeons, 1111 Amsterdam Avenue, New York, NY 10025. Fax: 212-523-4311; E-mail:
[email protected]
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diac ultrasound imaging at the patient bedside.6 HCU has recently been used as an aid to the physical examination,7 in the critical care setting,8 by the noncardiology medical community,9 and after limited echo training.10 There has been continuous progress and technical advancement in the development of HCU units. Their routine clinical use has been partially limited because of restricted diagnostic spectrum: the lack of acceptable image quality, and absence of continuous/pulsed-wave Doppler. However, the new HCU machines have harmonic imaging and spectral Doppler (pulsed/continuous-wave) capabilities, resulting in better diagnostic accuracy.11 Siemens Medical Solutions USA, Inc. has recently incorporated a TEE connector, which connects to its Cypress (highly miniaturized echocardiogram) unit and allows the performance of a TEE using a standard TEE multiplane probe (Fig. 1). HCU was defined as an echocardiogram machine of less than 6 lb. The Cypress unit is slightly heavier, but is considered a miniaturized echocardiogram unit. In this paper; we discuss our initial experience performing TEEs
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at the bedside based on indications and patient mobility. Typically, a routine TEE in the echo lab involves an echo technician, a nurse, a cardiology fellow, a cardiology imaging fellow, and an echo attending. As of January 2004, we have been performing TEEs using a standard multiplane TEE probe with the Cypress unit. The standard TEE imaging was completed in the routine manner with the standard echo machine. The probe was left in and was connected to the Cypress machine for additional imaging and comparison. TEE is a semi-invasive procedure which has carrier low risk. The information obtained from
Figure 1. A. Cypress-miniaturized echocardiogram unit. B. Cypress-miniaturized echocardiogram unit with TEE transducer connector.
using the Cypress unit. St. Luke’s-Roosevelt Hospital is a university hospital of Columbia University College of Physicians and Surgeons. This is a tertiary care center, designated trauma center, with multiple critical care units including Cardiac Care Unit, Open Heart Recovery Unit, Stroke Unit, Medical Intensive Care Unit, and Surgical Intensive Care Unit. All of these units are located in a building separate from the echocardiography lab, thus requiring the use of a bridge and two elevators to transport the patient to the lab or to transport the echo machine to the patient bedside. Having a small portable miniaturized device located in the Cardiac Care Unit enables us to perform urgent studies at bedside quickly and efficiently. The majority of our TEEs are performed in the echo lab while the remainder are performed 810
Figure 2. A. TEE performed in a 75-year-old male with severe dilation of the proximal descending aorta, with intramural hematoma, severe aortic plaque measuring 1.1 cm, and “smoke” in the lumen of the aorta, with Sequoia Accuson unit. B. TEE performed with Cypress-miniaturized echocardiogram unit in the same patient as described in Figure 2A.
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the procedure should be optimal. The imaging quality obtained with the Cypress unit was graded as equivalent and “optimal” by all operators to the point that we did not feel that there was any need to acquire concurrent imaging with the regular echo machine. There was no evidence of suboptimal results Figure 2A shows a TEE performed with a high-end echo machine in a 75-year-old male with severe dilation of the proximal descending aorta, with intramural hematoma, severe aortic plaque measuring 1.1 cm, and “smoke” in the lumen of the aorta. Figure 2B shows the same finding by imaging obtained from the hand-carried ultrasound unit.
Figure 3. A. Pulse wave Doppler left-upper pulmonary vein velocity in a 50-year-old female with a stroke, with Sequoia Accuson unit. B. Pulse wave Doppler left-upper pulmonary vein with Cypress-miniaturized echocardiogram unit in same patient as described in Figure 3A.
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Figure 3 demonstrates a pulse wave Doppler left-upper pulmonary vein velocity in a 50-yearold female with a stroke, using high-end echo machine (Fig. 3A) and the hand-carried ultrasound unit (Fig. 3B). Figure 4A and 4B demonstrates a long-axis transgastric TEE of an 82-year-old male with a light chain monoclonal gammopathy with severe concentric left ventricular hypertrophy and a moderate pericardial effusion, obtained with a Sequoia Accuson unit (Fig. 4A) and with Cypress unit (Fig. 4B). Figure 5A and 5B demonstrates short-axis transgastric TEE of the same patient seen in
Figure 4. A. A long-axis transgastric TEE of an 82-yearold male with a light chain monoclonal gammopathy with severe concentric left ventricular hypertrophy and a moderate pericardial effusion, with Sequoia Accuson unit. B. A long-axis transgastric TEE of an 82-year-old male with a light chain monoclonal gammopathy with severe concentric left ventricular hypertrophy and a moderate pericardial effusion, with Cypress unit.
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Figure 5. A. A short axis transgastric TEE obtained with Sequoia Accuson unit of the same patient described in Figure 4A. B. A short axis transgastric TEE obtained with Cypress unit of the same patient described in Figure 4B.
Figure 6: Algorithm for transesophageal echocardiography in the critical care unit.
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Figure 4A and 4B using a Sequoia Accuson unit (Fig. 5A) and with Cypress unit (Fig. 5B). Our current algorithm for performance of urgent TEE for in-hospital patients in the critical care unit is seen in Figure 6. A request for TEE is made to the echo lab by the critical care unit. If the patient can be mobilized, he will be transported to the echo lab and undergo TEE using the high-end ultrasound unit. However, if the patient cannot be mobilized then the TEE multiplane transducer is brought to the critical care unit and the procedure will be performed using the Cypress unit. From our initial experience, we have noticed the following advantages of this algorithm: 1. Equivalent quality of 2D imaging. 2. Relative ease of use. 3. Portability. 4. Overall shorter duration for the TEE procedure, saving the time of mobilizing the highend machine from the echo lab and waiting for its availability. 5. Ability to utilize non-HCU units for other procedures. 6. Elimination of the need for an echo technician to be involved in the procedure. The limitations of TEE using Cypress unit include: (1). The color Doppler is limited by the color scale to a Nyquist limit of 60 cm/sec. (2). There is no color/M-mode combination available. In conclusion, a miniaturized echocardiogram device may be used for portable transesophageal echocardiograms, especially in a critical care setting, giving satisfactory studies
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more efficiently, thus freeing up the non-HCU units for other procedures, and eliminating the need for an echo technician in the procedure. References 1. Seward JB, Khanddheria BK, Oh JK, et al: Transesophageal echocardiography: Technique, anatomic correlations, implementation, and clinical applications. Mayo Clin Proc 1988;63:649–680. 2. Oh JK, Seward JB, Tajik AJ: Transesophageal echocardiography. In The Echo Manual, 2nd Ed. Chapter 3. Philadelphia, New York: Lippincott-Raven Publishers, 1999. pp. 23–36. 3. Otto CM: Transesophageal echocardiography. In Textbook of Clinical Echocardiography, 2nd Ed. Chapter 3. Philadelphia, W. Saunders, 2000. pp. 59. 4. Roelandt J, Wladimiroff JW, Baars AM: Ultrasonic real time imaging with a hand-held scanner. Part II: Initial clinical experience. Ultrasound Med Biol 1978;4:93–97. 5. Kronzon I: The hand-carried ultrasonic revolution. Echocardiography 2003;20(5):453–454. 6. Gorcsan J: Utility of hand-carried ultrasound for consultative cardiology. Echocardiography 2003;20(5): 463–469. 7. DeCara JM, Lang RM, Spencer KT: The hand-carried echocardiographic device as an aid to the physical examination. Echocardiography 2003;20(5):477– 485. 8. Spevack DM, Tunick PA, Kronzon I: Hand-carried echocardiogrpahy in the critical care setting. Echocardiography 2003;20(5):455–461. 9. Duvall WL, Croft LB, Goldman ME: Can handcarried ultrasound devices be extended for use by the noncardiology medical community? Echocardiography 2003;20(5):471–476. 10. Lemola K, Yamada E, Jagasia D, et al: A hand-carried personal ultrasound device for rapid evaluation left ventricular function: Use after limited echo training. Echocardiography 2003;20(4):309–312. 11. Borges AC, Knebel F, Walde T, et al: Diagnostic accuracy of new handheld echocardiography with Doppler and harmonic imaging properties. J Am Soc Echocardiogr 2004;17:234–238.
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