Transthoracic Echocardiography in the Preoperative Clinic

Abstract

Whilst conventional (‘quantitative’) transthoracic echocardiography (TTE) performed by an echocardiography laboratory remains a useful diagnostic tool for non-invasive cardiac assessment, limited availability, cost, and a time-delay between request and result restrict its use. However, increased availability, portability and imaging capability of TTE equipment has enabled treating physicians to perform their own ‘focused TTE’ as an aid to initial clinical assessment at the ‘point-of-care’ when required. Initially embraced by critical care and emergency physicians for rapid assessment of shock, anaesthetists are increasingly using focused TTE for perioperative cardiac assessment. An abbreviated ‘qualitative’ study enables convenient separation of significant from non-significant cardiac pathology and helps identify the causes for persistent hypotension, such altered preload, afterload, pump or valve failure, tamponade or pulmonary hypertension. When incorporated into routine initial patient assessment of patients at increased cardiac risk presenting to the preoperative clinic before non-cardiac surgery, focused TTE changes the diagnosis and management in approximately 50 % of patients. Identification of previously unknown cardiac disease alerts the anaesthetist to increased perioperative risk, prompting an escalation in preoperative work-up, perioperative haemodynamic monitoring and management and increased use of postoperative intensive or high dependency care. Conversely, reassuring TTE enables a step-down in care, preventing unnecessary surgical delay for investigations or referral, and circumventing the need for invasive monitoring during or after surgery. Focused TTE may assist anaesthetists assess and manage the increasing number of patients presenting to surgery with increased age and increasingly complex co-morbidities admitted on the day of surgery.