Department of Medicine
University of Wisconsin
Echocardiography and Vascular Laboratory
The Adult Echo and Vascular Laboratory, directed by Peter Rahko, MD and William Turnipseed, MD, performs more than 14,400 procedures annually, including 8,000 diagnostic transthoracic echocardiograms at four sites in Madison as well as 6,400 peripheral vascular studies at two sites in Madison. The primary facility is at UW Hospital and Clinics. It includes newly constructed laboratories for transthoracic echo and vascular imaging, a dedicated transesophageal procedure suite and two dedicated stress echo laboratories. State-of-the-art Philips 7500 and 5500, Acuson Sequoia and GE Vivid 7 imaging systems are used. The laboratory is a full digital image management lab for all sites using a Camtronics ultrasound image acquisition, storage and report generation system. A digital tape server system with rapid acquisition capabilities provides long-term mass storage. Three state-of-the-art reading rooms are used for viewing and teaching. Additional full reading stations are located on the inpatient service unit in UW Hospital and at each Cardiovascular Medicine Clinic. Ultrasound reports are generated on-line using a computerized report system and database.
Three satellite laboratories at the Atrium and UW Hospital's large multispecialty ambulatory clinics on the east and west sides of Madison and Atrium are linked by fiber to the main laboratory for rapid, on-line transmission of all images. Each laboratory contains one or two Phillips 5500 ultrasound imaging system(s) and a GE Marquette digital treadmill system. The satellite laboratories, located within cardiovascular medicine clinics, perform both transthoracic and treadmill stress echocardiograms.
The transesophageal echocardiography program, initiated in 1988, performs more than 600 procedures annually. The laboratory uses multiplane transducer technology exclusively. Procedures are performed on ambulatory and hospitalized patients, in intensive care units, the emergency department and the operating room. Faculty from the echocardiography laboratory work closely with cardiothoracic surgeons and anesthesiologists for imaging during cardiovascular surgery. Two additional dedicated Philips ultrasound systems are used for this purpose.
Stress testing is performed in the echocardiography laboratory utilizing standard treadmill exercise protocols or dobutamine infusion. Diagnostic studies to evaluate ischemic heart disease and myocardial viability constitute the majority of the studies performed. The laboratory also offers several innovative diagnostic studies for specialized purposes. These include combined stress echocardiography with VO2 oxygen consumption analysis for heart failure patients, quantification of exercise-induced gradients for patients with stenotic valvular heart disease, evaluation of ventricular response to exercise in patients with regurgitant valvular heart disease, and evaluation of hemodynamic responses of patients with hypertrophic cardiomyopathy. Contrast echocardiography with second harmonic and newer imaging modalities are used extensively for resting and stress echocardiographic studies.
The laboratory performs 3-D reconstruction of transesophageal and transthoracic images using the Tom-Tec 3-D acquisition and analysis system.
The laboratory partners with the interventional cardiovascular group for evaluation and treatment of disorders of the atrial septum. Using the Seimens-Acuson Acu-Nav intracardiac imaging transducer, echocardiography faculty image the atrial septum during device closure of atrial septal defect and patent foramen ovale.
Recently the laboratory merged with the Vascular Imaging Laboratory, directed by William Turnipseed, MD, Chair of the Division of Peripheral Vascular Surgery. The combined laboratory offers vascular imaging to a wide array of patients with carotid, renal arterial, peripheral arterial and peripheral venous disease.
Wide-ranging clinical research studies have been performed and continue to be developed in the cardiovascular ultrasound laboratory.
The laboratory has used the flexibility of cardiac ultrasound for evaluating ventricular functional responses to several provocative stimuli, including lower body negative pressure, tilt table testing, dead lifts and pharmacologic stress. The laboratory has studied new ultrasound contrast agents and performed serial ventricular function testing in several national studies of heart failure therapy.
Recently, the associate laboratory director, James Stein, MD, developed a substantial atherosclerosis imaging program for both clinical and research applications. The Vascular Health Screen Exam uses carotid intimal medial thickness measures, ankle-brachial indexes, serum lipid assessment, and Framingham risk scores to calculate vascular age and better quantify cardiac risk. Other research uses analysis of brachial artery reactivity to assess endothelial function in a variety of clinical conditions. The technique is being used to assess changes in endothelial function and reactivity during interventional trials in select patient populations. The laboratory recently initiated a program in three-dimensional imaging and reconstruction to further enhance the quantitative capabilities of cardiovascular ultrasound. Recently, new research protocols evaluating vascular stiffness, ventricular arterial coupling and LV diastolic performance have been initiated. The laboratory continues to partner with industry to evaluate new software and hardware advances in image management. Studies involving new forms of ultrasound imaging equipment are ongoing. Basic research using cardiovascular ultrasound is performed in conjunction with several laboratories on campus.
Educational opportunities in the adult echocardiography laboratory include monthly rotations for Cardiovascular Medicine fellows. A dedicated fully funded fourth year fellowship position is available for advanced training in clinical and research echocardiography. Weekly case presentation conferences and quality assurance conferences are held in the Division of Cardiovascular Medicine. A didactic lecture series for fellows is given annually. Faculty of the echocardiography laboratory also participate in the School of Diagnostic Ultrasonography, which trains sonographers and has a dedicated program in echocardiography.
Echocardiography and Vascular Laboratory Faculty