Intraoperative epicardial echocardiography with a miniature high-frequency transducer: imaging techniques and scanning planes.

Abstract

Intraoperative Doppler echocardiography has the potential to provide anatomic and functional information but is hindered by the large size of standard transducers. We describe new scanning planes accessible through the application of a new 5 MHz miniature transducer with imaging, Doppler, and color-flow capability. Epicardial echocardiography was performed in 15 adults undergoing elective coronary artery bypass grafting. Standard parasternal equivalent, subcostal equivalent, aortopulmonary sulcus and aortosuperior vena caval views were obtained. Previously unobtainable apical four-chamber, five-chamber, and long-axis views were possible by positioning the transducer at the apex. The transducer has a broad bandwidth, allowing high-quality imaging at different depths and could be maneuvered laterally, posteriorly, and over the aorta and pulmonary arteries to provide off-axis views. The proximal-mid coronary arteries were imaged on the beating heart with a standoff medium. Transducer miniaturization should expand the role of epicardial ultrasonography in the surgical management of heart disorders.