The Cardiovascular Imaging Research Section – Echocardiography

Contrast echocardiography

Clinical research is currently being conducted in the field of echocardiography referred to as myocardial contrast perfusion. This will potentially be useful to examine coronary artery disease by means of echocardiography. Echo contrast is injected into an arm vein during an echo exam allowing for "real time" imaging of perfusion. The benefit of contrast echo is that there is no exposure to radiation and the exam can be done virtually anywhere in the hospital or doctor’s office.

Physicians: Dr. Klein, Dr. Afridi, Dr. Grimm, Dr. Rodriguez, and Dr. Thomas
Contact person: Annitta Morehead, RDCS (216) 445-7673

Echocardiography in Space

The Imaging center is currently involved in clinical trials to design and develop the first telemedicine link form the International Space Station to Earth in order to provide cardiac consultation. This work will study the impact of digital compression on ultrasound images. Additionally, scientists are studying the effects of long-term weightlessness on the heart by echocardiography.

Physicians: Dr. Thomas, Dr. Rodriguez, and Dr. Garcia
Contact person: Annitta Morehead, RDCS (216) 445-7673

Publications:

• Thomas JD. Digital storage and retrieval: the future in echocardiography. Heart (suppl.) 1997;78:19-22 Stugaard M, Greenberg NL, Zhou J, Thomas JD: Automated eigenvector analysis for quantification of color M-mode Doppler filling patterns of the left ventricle in an ischemic canine model. Computers in Cardiology 1997 (IEEE Press, Picataway, NJ, 1997); 61-64.
• Spence M, Freeman K, Morehead A, Thomas J: Real-time transmission of echocardiographic images over high speed networks: Effects of bandwidth, cell loss ratio and cell error ratio on image quality. J Am Coll Cardiol 1998;31(2):259A
• Thomas JD. Digital echocardiography being explored for space-based diagnosis. Cardiac Consult (CCF) 1997;8:2-3

Cardioversion using Transesophageal Echocardiography (TEE)

The following studies are being conducted to look at a transesophageal esophageal (TEE) approach to cardioversion:

ACUTE Pilot Study

An assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) Pilot Study was a randomized multicenter pilot study that compared a transesophageal echocardiography (TEE) guided approach to cardioversion of patients in atrial fibrillation greater 2 days duration to the conventional approach to cardioversion. The ACUTE Pilot enrolled 126 patients from 10 clinical centers and showed that the TEE guided approach was feasible and safe and was associated with a shorter time to cardioversion and a resulting reduced patient anticoagulation burden on the patient.

Physicians: Dr. Klein, Dr. Grimm
Contact Person: Susan Jasper, RN or Ariel Goodman, BA (216) 445-7673

Publications:

• Klein AL, Grimm RA, Black IW, Leung DY, Chung MK, Vaughn SE, Murray RD, Miller D, Arheart KL. Transesophageal echocardiographic-guided cardioversion: a randomized controlled clinical trial - The ACUTE pilot study. Ann Intern Med 1997;126:200-9.

ACUTE Multicenter Study

Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) Multicenter Study - The ACUTE Multicenter Study is a randomized clinical trial comparing a transesophageal echocardiography (TEE) guided approach to cardioversion of patients in atrial fibrillation >2 days duration to the conventional approach to cardioversion. Outcomes include embolic events, bleeding, death, cost, and quality of life for an 8-week period. The ACUTE Multicenter Study enrolled a total of 1226 patients from over 40 clinical centers and is currently under analysis. Differences in outcome will be derived from the ability of TEE to screen for left atrial thrombus and delay cardioversions in these patients.

Physicians: Dr. Klein, Dr. Grimm
Contact Person: Susan Jasper, RN or Ariel Goodman, BA (216) 445-7673

Publications:

• Murray RD, Goodman AS, Lieber EA, Jasper SV, Grimm RA, Garcia M, Miller DM, Klein AL. National use of the transesophageal guided approach to cardioversion for patients in atrial fibrillation. Am J Cardiol 2000 (in press).

ACUTE II Pilot Study

Assessment of Cardioversion Using Transesophageal Echocardiography II (ACUTE II) Pilot Study - The ACUTE II Pilot Study is a randomized clinical trial comparing a transesophageal echocardiography (TEE) guided low-molecular-weight heparin (enoxaparin) approach to a TEE guided standard unfractionated heparin approach for immediate cardioversion of patients in atrial fibrillation >2 days duration. A total of 200 patients will be randomly assigned to either arm and followed for a 5-week study period. Patients identified with left atrial appendage thrombus on initial TEE will be followed for a total of 8-weeks in order to monitor the resolution of thrombus and clinical outcome. Differences in primary outcome between the two strategies will be derived from the ability of enoxaparin to provide a clinically effective bridge antithrombotic agent as a convenient and economically attractive alternative to intravenous unfractionated heparin.

Physicians: Dr. Klein, Dr. Grimm
Contact Person: Susan Jasper, RN or Ariel Goodman, BA (216) 445-7673

Publications:

• Murray RD, Shah A, Jasper SE, Goodman A, Deitcher SR, Katz W, Malouf JF, Stoddard MF, Klein AL, for the ACUTE II Pilot Study Investigators. Design of a Pilot Study to Test the Feasibility, General Safety, and Economics of a Transesophageal Echocardiography Guided Low Molecular Weight Heparin (Enoxaparin) Approach to Cardioversion of Patients in Atrial Fibrillation: The ACUTE II Study. (under review)
• Murray RD, Deitcher S, Shah A, Jasper S, Bashir M, Grimm RA, Klein AL. Potential clinical efficacy and cost benefit of a TEE guided low molecular weight heparin approach to antithrombotic therapy in patients undergoing immediate cardioversion from atrial fibrillation (under review)

Visualization of thrombus in left atrial appendage (CLOTS Study)

Comprehensive Left Atrial Appendage Optimization of Thrombus Identification Using Surface Echocardiography (CLOTS). The objectives of the CLOTS Study is to evaluate the ability to visualize, and identify thrombus within, the LAA using transthoracic echocardiographic modalities, including fundamental, harmonic, pulse inversion, and color TDI imaging, compared to the transesophageal standard. Secondly, to establish a potential relationship between Doppler-measured LAA flow velocities (in fundamental and harmonic transthoracic imaging) and presence of thrombus. Also under investigation is the relationship between pulsed TDI derived LAA wall and cavity velocities and presence of thrombus. Finally, to evaluate the potential additive resolution/signal quality benefit of intravenous contrast to the above modalities.

Physicians: Dr. Klein, Dr. Grimm, Dr. Asher
Contact Person: Susan Jasper, RN or Ariel Goodman, BA (216) 445-7673

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