The epidemic of heart failure is a worldwide problem that is anticipated to increase with both an aging population and the improved survival from cardiac complications producing left ventricular systolic dysfunction (e.g. myocardial infarction). Increasingly, these patients who survive a serious cardiac injury but have persistent ventricular dysfunction precluding normal end-organ function experience a poor quality of life and high rates of morbidity and mortality. At the age of 40, the lifetime risk of developing heart failure is 20%, and the 1-year heart failure mortality rate is 20%.1 The number of hospitalizations for heart failure has tripled between the 1970s and 2004, and contemporary data indicate that heart failure was the primary or secondary cause of 3.8 million annual admissions in the United States.2 It is estimated that the direct and indirect costs of heart failure in the United States will exceed $37 billion in 2009, highlighting the economic importance of this disease.1
While most heart failure patients are managed medically, surgical options for refractory heart failure include orthotopic heart transplantation and mechanical circulatory support. Advances in donor and recipient selection, organ procurement, and immunosuppressant therapy have led to an increase in the survival of grafted organs. Transplant surgery is currently considered the treatment of choice for end-stage heart, lung, and liver diseases, but the predominant limiting factor is a shortage of donors. Mechanical circulatory support has therefore emerged as a valuable and viable adjunct to transplantation in the management of heart failure patients.
Echocardiography plays an essential role in the donor organ selection process and preoperative screening, perioperative management, and post-transplant follow-up of recipients. Similarly, perioperative transesophageal echocardiography (TEE) provides invaluable anatomic and functional information in patients receiving circulatory support devices, which influence not only anesthetic management but also surgical decision making. The following text will first describe the role of TEE in heart transplantation, followed by a discussion of its value in the implantation of mechanical circulatory support devices.
The application of TEE as a diagnostic and monitoring modality in heart transplant surgery can be divided into five categories:
Cardiac donor screening
Intraoperative monitoring in the pretransplant period
Intraoperative evaluation of cardiac allograft function and surgical anastomoses in the immediate posttransplantation period
Management of early postoperative hemodynamic abnormalities in the intensive care unit
Postoperative follow-up studies of cardiac allograft function
Role of TEE in Cardiac Donor Screening
As a result of the shortage of available donor hearts, many institutions are now liberalizing their acceptance criteria to include higher-risk (marginal) donor hearts.3 Table 17–1 presents the conventional cardiac contraindications to the use of a donor heart. Despite the potential risk for transmitting atherosclerotic, hypertensive, and valvular heart diseases, organs from older donors are increasingly being used. This aggressive approach has proved particularly successful when matching for higher-risk recipients (alternate recipient list) with a greater short-term mortality risk or with significant comorbid factors.4...