In:
Journal of Applied Physiology, American Physiological Society, Vol. 90, No. 1 ( 2001-01-01), p. 299-307
Abstract:
Myocardial tissue Doppler echocardiography (TDE) has been proposed as a tool for the assessment of diastolic function. Controversy exists regarding whether TDE measurements are influenced by preload. In this study, left ventricular volume and high-fidelity pressures were obtained in eight closed-chest dogs during intermittent caval occlusion. The time constant of isovolumic ventricular relaxation (τ) was altered with varying doses of dobutamine and esmolol. Peak early diastolic myocardial ( E m ) and transmitral ( E) velocities were measured before and after preload reduction. The relative effects of changes in preload and relaxation were determined for E m and compared with their effects on E. The following results were observed: caval occlusion significantly decreased E (Δ E = 16.4 ± 3.3 cm/s, 36.6 ± 13.7%, P 〈 0.01) and E m (Δ E m = 1.3 ± 0.4 cm/s, 32.5 ± 26.1%, P 〈 0.01) under baseline conditions. However, preload reduction was similar for E under all lusitropic conditions ( P = not significant), but these effects on E m decreased with worsening relaxation. At τ 〈 50 ms, changes in E m with preload reduction were significantly greater (Δ E m = 2.8 ± 0.6 cm/s) than at τ = 50–65 ms (Δ E m = 1.2 ± 0.2 cm/s) and at τ 〉 65 ms (Δ E m = 0.5 ± 0.1 cm/s, P 〈 0.05). We concluded that TDE E m is preload dependent. However, this effect decreases with worsening relaxation.
Type of Medium:
Online Resource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/jappl.2001.90.1.299
Language:
English
Publisher:
American Physiological Society
Publication Date:
2001
detail.hit.zdb_id:
1404365-8
SSG:
12
SSG:
31
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