The use of echocardiography in anaesthesia and critical care started with transoesophageal echocardiography, whereas transthoracic echocardiography was largely the domain of the cardiologist. In ...recent times, there has been a change in focus towards transthoracic echocardiography owing to the development of small and portable, yet high-fidelity, echocardiography machines. The cost has reduced, thereby increasing the availability of equipment. A parallel development has been the concept of limited transthoracic echocardiography that can be performed by practitioners with limited experience. The basis of these examinations is to provide the practising clinician with immediate information to help guide management with a focus on haemodynamic evaluation, and limited structural (valve) assessment to categorise whether there is a valve disorder that may or may not cause haemodynamic instability. The limited examination is therefore goal directed. A number of named examinations exist which differ in their scope and views. All of these require a limited knowledge base, and are designed for the clinician to recognise patterns consistent with haemodynamic or anatomical abnormalities. They range from very limited two-dimensional assessments of ventricular function to more complex (yet presently limited) studies such as HEART (haemodynamic echocardiography assessment in real time) scan, which is designed to provide haemodynamic state, as well as basic valvular and pericardial assessment. It is suitable for goal-directed examination in the operating theatre, emergency department or intensive care unit (ICU) and for preoperative screening.
Objective To assess the feasibility and correlation between tissue Doppler and speckle tracking imaging when measuring myocardial velocity, strain, and strain rate with transesophageal ...echocardiography. Design A prospective, observational study. Setting An academic tertiary-referral hospital. Participants Patients undergoing elective heart surgery. Interventions None. Measurements and Main Results Velocity, strain, and strain rate were measured using both techniques in the inferior and anterior walls in transgastric views for radial motion and in the lateral, septal, anterior, and inferior walls in midesophageal views for longitudinal motion. Nineteen patients and 304 myocardial segments were studied. Overall, tissue Doppler was found to be more successful than speckle tracking in measuring myocardial velocity, whereas strain and strain rate measurements were achieved with comparable success using either method. Tissue Doppler was more successful than speckle tracking for radial cardiac motion, and the highest success rates were achieved with this method (93.4% v 59.2% for velocity, p < 0.001; 78.9% v 59.2% for strain, p = 0.01; and 73.7% v 59.2% for strain rate, p = 0.09). Good correlation between tissue Doppler and speckle tracking was shown in 4 myocardial segments: radial midinferior, radial basal inferior, radial basal anterior, and longitudinal basal septum ( R = 0.6-0.82, p < 0.05). Conclusions The correlation between tissue Doppler and speckle tracking with transesophageal echocardiography appears valid when predominantly confined to segments moving in a radial direction adjacent to the ultrasound transducer. Tissue Doppler echocardiography of radial cardiac motion appears to be the most feasible technique of measuring myocardial velocity, strain, and strain rate during cardiac surgery.
