Preload Dependence of Doppler Tissue Imaging Derived Indexes of Left Ventricular Diastolic Function

Doppler tissue imaging (DTI) has been proposed as a tool for the evaluation of diastolic function. Controversy exists regarding whether DTI measurements are influenced by preload. Changes in the circulating volume associated with hemodialysis result in preload reduction. To determine the influence of preload reduction on DTI and standard pulsed-Doppler transmitral diastolic velocities, 30 patients (mean age 41 +/- 14) with chronic renal insufficiency without overt heart disease were studied by DTI and standard pulsed Doppler before and after hemodialysis. From the apical window, DTI sample volume was placed at the lateral and septal mitral annulus and at the midsegment of lateral and septal myocardial wall of the left ventricle. Peak early diastolic annular and myocardial, and peak late diastolic annular and myocardial velocities were measured. Transmitral peak early and late diastolic velocities were also recorded by standard pulsed Doppler. The peak velocity of early diastolic mitral flow decreased from 100 +/- 30 to 85 +/- 34 cm/s (P < 0.001) after hemodialysis. Hemodialysis elicited marked reduction in early diastolic lateral mitral annular and midlateral myocardial velocities (6.9 +/- 3.2 to 6.3 +/- 2.9 cm/s, P < 0.04 and 6.7 +/- 0.3 to 5.5 +/- 2 cm/s, P < 0.001, respectively). Early diastolic, septal mitral annular, and midseptal myocardial velocities were also significantly decreased (5.8 +/- 2.8 to 4.6 +/- 2 cm/s, P < 0.006 and 6.2 +/- 2 to 5.1 +/- 1 cm/s, P < 0.008, respectively). Late diastolic mitral annular and myocardial velocities did not change. It is concluded that early diastolic mitral annular and myocardial velocities are affected by acute preload reduction. It is necessary to consider preload when diastolic function is assessed by DTI.