TEE and Perfusion Distribution
TEE is an evaluation of Ventricular functions and has been crucial in the OR – goal of intraoperative ventricular function monitoring provides:
Goals of Ventricular Function Monitoring
- continuous global function assessment
- volume status information
- regional function assessment as a reflection of acute coronary ischemia
- left atrial pressure estimation
In concentrating on TEE’s role in assessing acute coronary ischemia and since active ischemia can be seen on a TEE much earlier than any changes in EKG, interpretation of any wall motion abnormalities and how they correlate to coronary artery distribution can be crucial to intraoperative management for an anesthesiologist.
Transgastric Short-Axis View
The short-axis view at the midpapillary muscle level is a commonly used view for evaluating global and segmental ventricular performance. All three coronary territories are represented in this view, making it useful for detecting acute ischemia.
Transgastric Long-Axis View
The transgastric long-axis view is also useful, as the left ventricular apex is imaged most readily in this plane. This is especially important when isolated abnormalities confined to the apex are sought by TEE. This view is also useful in measuring cardiac output through continuous wave Doppler interrogation of the aortic valve. Estimations of cardiac output with this approach correlate well with more direct measures of global function.
Midesophageal Four-Chamber View
The midesophageal four-chamber view allows simultaneous visualization of the left and right ventricles and is analogous to the identically named apical transthoracic echocardiographic view. Segmental function of the lateral and the septal walls is best assessed in this view.