Heart failure represents a major public health problem worldwide. There are approximately 5.1 million patients diagnosed with this disease in the United States, and more than 650,000 new heart failure cases are diagnosed every year. In fact, in the United States the lifetime risk for developing heart failure is more than 20% for individuals more than 40 years old. As the U.S. elderly population is continuously growing, the expected incidence of heart failure will rise. Therefore, the health care cost and burden of heart failure in medical systems will become even more significant.1
The “gold standard” treatment for patients with end-stage heart failure is cardiac transplantation. This treatment provides significant benefit in survival and quality of life for such patients. Unfortunately, the limited supply of donor organs makes this treatment an option for a few carefully selected patients. In fact, a significant proportion of patients die while waiting for heart transplantation. The use of mechanical circulatory support devices (MCSD) has become an alternative for end-stage heart failure patients for treatment in both the short term and long term. In recent years, the field of mechanical circulatory support has greatly expanded, displaying a wide array of options, from transient support of patients undergoing high-risk percutaneous interventions to destination therapy as a long-term alternative to heart transplantation.
Transesophageal echocardiography (TEE) plays an essential role as a diagnostic and management tool in a diversity of situations involving clinical care of patients undergoing mechanical circulatory support. This chapter will discuss the applications and highlight the versatility of TEE in management of patients with contemporary MCSDs.
CURRENT MECHANICAL CIRCULATORY SUPPORT DEVICES
Technological developments during the last decades have resulted in devices with diverse mechanisms of action, modes, and place of implantation, as well as support capabilities. It is possible to provide partial or complete ventricular function support for one or two ventricles. MCSDs can be used as temporary interventions while a long-term therapeutic option becomes possible (e.g., transplantation or long-term circulatory support) or there is myocardial recovery, or as a long-term support therapy. Devices can be classified according to the type of flow provided–pulsatile or continuous flow, or regarding their pump mechanism of action–centrifugal or axial. Other modes of classification include short-term vs. long-term, mode of implantation (percutaneous vs. surgically implanted), location (intracorporeal vs. extracorporeal), and the ventricle supported (left, right, or biventricular).2 The details about mechanisms of action, placement, and selection of MCSDs are beyond the scope of this chapter. We will briefly describe the most commonly used contemporary devices available (Fig. 17-1).
(A) HeartMate® II Left Ventricular Assist System (LVAS; Heart Mate II, Heart Mate 3 and St. Jude Medical are all tradmarkes of St. Jude Medical, LLC or its related companies. Reproduced with permission of St. Jude Medical, ©2018. All rights reserved). ...