Transesophageal echocardiography in review

Recent advances in ultrasound technology

Technical improvements have made profound changes in diagnostic ultrasound imaging. Some of these changes, such as encoded pulses and receive focusing, occur in the background and are essentially nonadjustable. Others, including harmonics and compounding, are real-time options and are adjustable by the imager. New technologies that offer great promise for improved characterization of lesions include contrast ultrasound and elastography. This article will attempt to update the small animal imager on the clinical applications of these newer technologies.

Measurement of intracardiac dimensions and structures in normal young adult subjects by transesophageal echocardiography

Transesophageal echocardiography (TEE) has proven to be an excellent diagnostic means of diagnosing different cardiac diseases. To distinguish between normal and pathologic findings, standardized measurements of well-defined cross-sectional planes are necessary. Therefore, the 2-dimensional echocardiographic data of 25 healthy volunteers were obtained. In 13 men and 12 women, aged 19 to 30 years, recordings of the left ventricular short-axis view, the 2- or 4-chamber view with the left and right atria, the long axes of the left and right ventricles, the mitral and tricuspid valve ring and the atrial septum were analyzed. Furthermore, the aortic valve plane and the ascending and descending aorta were also measured. All data are given as mean values +/- 2 times the standard deviation. End-diastolic and end-systolic left ventricular anterior-to-posterior diameter of the left ventricular short axis was 2.5 +/- 0.3 cm/m2 and 1.7 +/- 0.3 cm/m2, with the fractional shortening ranging from 27 to 42%. The end-systolic lateral diameter was 2.4 +/- 0.5 cm/m2 for the left atrium and 2.4 +/- 0.4 cm/m2 for the right atrium, and the end-systolic anterior-to-posterior diameter was 1.5 +/- 0.6 cm/m2 for the left atrium and 2.1 +/- 0.6 cm/m2 for the right atrium. End-diastolic diameters of 3.4 +/- 0.6 cm/m2 and 2.8 +/- 0.4 cm/m2 were obtained for the long axis of the left ventricle and for the right ventricle. Measurements ranged from 1.5 to 2.2 cm/m2 for the end-diastolic diameter of the mitral ring and from 1.3 to 2.0 cm/m2 for the tricuspid ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Transesophageal echocardiography

Two-dimensional transesophageal echocardiography generally has superior sensitivity and image quality compared with precordial echocardiography. Its unique anatomic perspective posterior to the heart often provides important clinical information not obtainable by other imaging approaches and technologies. It is particularly useful in the diagnosis of mitral valve disease, left atrial masses, endocarditis and its sequelae, and aortic dissections. It is also useful for examination of the left main coronary artery, left ventricular outflow tract, atrial and ventricular septa, and congenital defects. In addition to its application as a diagnostic tool in conscious patients, it can be employed intraoperatively to evaluate and guide surgical intervention. Detection of ventricular wall motion abnormalities by transesophageal echocardiography has been shown to be the most sensitive indicator of myocardial ischemia available in the clinical setting. It has potential for wide application for safely monitoring left ventricular function in patients in intensive care or under anesthesia.