ISSN:
1573-0743
Keywords:
afterload
;
diastolic filling patterns
;
Doppler echocardiography
;
normal subjects
;
preload
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The net effects of acute changes in pre- and afterload on left ventricular filling, were examined by altering loading conditions in normal subjects. The specific purpose of this study was to investigate whether Dopplerderived transmitral flow patterns are able to differentiate the type of loading conditions. In 24 normal subjects (13 females, 11 males, mean age 44.1±11.5 years), the following Doppler variables were determined at baseline, after rapid volume infusion (preload increase), after nitroglycerin administration (preload decrease), during isometric exercise (afterload increase), and after application of a converting enzyme inhibitor (afterload decrease): the 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 acceleration and deceleration times (Ac, dc) of early filling. Reduced preload and increased afterload led to similar filling patterns characterized by a significant E and Ei decrease (p〈0.05, compared to baseline) accompanied by an A and Ai increase with a resultant reduction of E/A and Ei/Ai. Both changes increased the atrial contribution to filling and reduced Ac and dc. Increased preload only significantly increased E and Ei, while reduced afterload did not induce any significant changes. Different loading conditions alter Doppler-derived diastolic filling patterns. However, the transmitral flow profile is not specific enough to distinguish the manner in which loading conditions have been altered.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01137149
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