Tissue Doppler in Everyday Diastolic Assessment

A diastolic dysfunction (DD) assessment algorithm may seem simple to apply however, it is not always straightforward. Flow-derived parameters define the behavior of the chamber in its entirety. These parameters are unfortunately preload sensitive. Furthermore, in the perioperative period patients are not under ambulatory conditions. Examinations under anesthesia and positive pressure ventilation may significantly colour the assessment. In the post-operative period the effects of surgery, CPB as well as intervening factors such as pericardial collections, right ventricular failure, pacing, arrhythmias, tachycardia or inotropic support may significantly influence the assessment. These conditions may change rapidly as the patient improves or worsens and may not be permanent. Initial examination: It is unusual for DD to be present without structural abnormalities. Increased LA size, a thickened interventricular septum and a depressed EF are predictors of DD. Although DD is assumed in systolic failure, a normal systolic function does not exclude DD. Changes in some of these parameters however, will not be present following acute changes in the perioperative setting. Physiology and Doppler parameters: 1) Increased LAP: If all other factors remain constant (relaxation, compliance and systolic function), an increase in LAP will result in a pulling up of the early filling portion of the PV loop (ie: earlier filling) and a move to the right of the end diastolic portion (larger volume). Please note that the diastolic compliance curve remains normal. An increase in LAP will result in: