Guidelines for the cardiac sonographer in the performance of contrast echocardiography: recommendations of the American Society of Echocardiography Council on Cardiac Sonography.

The impact of contrast agents (transpulmonary and agitated saline) on the clinical applications of echocardiography has been dramatic over the last decade.Currently, the Food and Drug Administration– approved indications for transpulmonary agents include the enhancement of left ventricular endocardial border definition.The augmentation of Doppler signals and intracardiac shunt detection can also be enhanced with the administration of contrast agents. The use of contrast agents in each of these clinical situations is well established and has become standard practice in many echocardiography laboratories.1 The development of newer agents promises to bring additional advances in the utility of contrast echocardiography, including the real-time assessment of myocardial perfusion2; coronary flow detection and flow reserve measurements3,4; the delivery of pharmacologic or genetic therapy5; and in combination with continuous ultrasonography,as a therapy for discriminatingly dissolving life-threatening blood clots.6 As these applications continue to expand, so must the role and responsibilities of the cardiac sonographer. Contrast echocardiography requires a high level of competence and expertise, in addition to the skills frequently required in standard cardiac sonography practice, such as assisting with transesophageal echocardiography and performing stress echocardiography, interventional and/or interoperative procedures, and fetal echocardiography.7 The American Society of Echocardiography (ASE) highly recommends that cardiac sonographers take the appropriate steps to become trained in the administration of the contrast agents used in echocardiography.The sonographer is often the first person to recognize the need for contrast, but the physician is ultimately responsible for ordering its use, which ideally should be done on a case-by-case basis. However, we recognize that there are situations in which the physician is not immediately available, and in such instances, another option might be the use of standing orders,with explicit indications listed as to when to use a contrast agent.This alternative would require active involvement of the laboratory medical director for the development of standing orders and specific protocols. The cardiac sonographer’s role in performing contrast echocardiography consists of 4 components: 1. A thorough understanding of microbubble physics, instrumentation, and the application of cardiac ultrasonographic scanning techniques for the acquisition of high-quality images during contrast administration. 2. Recognition of the indications for use of a contrast agent for left heart-chamber border delineation, enhancement of Doppler signals, and intracardiac/intrapulmonary shunt detection. 3. Obtainment of intravenous (IV) access or evaluation of an existing IV line for administration of a contrast agent by a sonographer. Guidelines for the Cardiac Sonographer in the Performance of Contrast Echocardiography: Recommendations of the American Society of Echocardiography Council on Cardiac Sonography