CHANGES OF TRANSMITRAL FLOW PATTERNS DUE TO DIFFERENT LOADING CONDITIONS IN NORMAL SUBJECTS

For a more precise understanding of the net effects of acute alterations of pre- and afterload on left-ventricular filling, loading conditions were altered in normal subjects. The specific purpose of this study was to investigate if Dopplerechocardiographically derived transmitral flow patterns are able to differentiate the manner of loading condition. In 24 normal subjects (13 female, 11 male, mean age 44.1 +/- 11.5 years) the following Doppler variables were analyzed at baseline, after rapid infusion of volume (preload increase), nitroglycerine (preload decrease), isometric exercise (afterload increase) and converting enzyme inhibitor (afterload decrease): peak and integrated early (E, Ei) and late (A, Ai) diastolic flow velocities, their ratios (E/A, Ei/Ai), the percentage of atrial contribution (ACON) and the times of acceleration (Az) and deceleration (Dz) of early filling. Preload reduction as well as afterload increase led to a similar filling pattern with a significant decrease (p < 0.05 from baseline) of E and Ei, increase of A and Ai, and, consequently, a reduction of E/A and Ei/Ai. The atrial contribution to filling increased during both alterations; Az and Dz were reduced. Following the increase of preload, only the increase of E and Ei was statistically significant, while afterload reduction showed no significant differences. Different loading conditions alter Doppler-derived diastolic filling patterns. But the transmitral flow profile is not specific enough to differentiate in which manner loading conditions have been altered.