Left ventricular twist mechanics during incremental cycling and knee extension exercise in healthy men

Beaumont, A, Hough, J ORCID: https://orcid.org/0000-0001-6970-5779, Sculthorpe, N and Richards, J, 2017. Left ventricular twist mechanics during incremental cycling and knee extension exercise in healthy men. European Journal of Applied Physiology, 117 (1), pp. 139-150. ISSN 1439-6319

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Abstract

Purpose: The objective of the present study was to investigate left ventricular (LV) twist mechanics in response to incremental cycling and isometric knee extension exercises.

Methods: Twenty-six healthy male participants (age = 30.42 ± 6.17 years) were used to study peak twist mechanics at rest and during incremental semi-supine cycling at 30 and 60% work rate maximum (W max) and during short duration (15 s contractions) isometric knee extension at 40 and 75% maximum voluntary contraction (MVC), using two-dimensional speckle tracking echocardiography.

Results: Data presented as mean ± standard deviation or median (interquartile range). LV twist increased from rest to 30% W max (13.21° ± 4.63° to 20.04° ± 4.76°, p < 0.001) then remained unchanged. LV systolic and diastolic twisting velocities progressively increased with exercise intensity during cycling from rest to 60% W max (twisting, 88.21° ± 20.51° to 209.05° ± 34.56° s−1, p < 0.0001; untwisting, −93.90 (29.62)° to −267.31 (104.30)° s−1, p < 0.0001). During the knee extension exercise, LV twist remained unchanged with progressive intensity (rest 13.40° ± 4.80° to 75% MVC 16.77° ± 5.54°, p > 0.05), whilst twisting velocity increased (rest 89.15° ± 21.77° s−1 to 75% MVC 124.32° ± 34.89° s−1, p < 0.01). Untwisting velocity remained unchanged from rest [−90.60 (27.19)° s−1] to 40% MVC (p > 0.05) then increased from 40 to 75% MVC [−98.44 (43.54)° s−1 to −138.42 (73.29)° s−1, p < 0.01]. Apical rotations and rotational velocities were greater than basal during all conditions and intensities (all p < 0.01).

Conclusion: Cycling increased LV twist to 30% W max which then remained unchanged thereafter, whereas twisting velocities showed further increases to greater intensities. A novel finding is that LV twist was unaffected by incremental knee extension, yet systolic and diastolic twisting velocities augmented with isometric exercise.

Item Type:	Journal article
Publication Title:	European Journal of Applied Physiology
Creators:	Beaumont, A., Hough, J., Sculthorpe, N. and Richards, J.
Publisher:	Springer
Date:	2017
Volume:	117
Number:	1
ISSN:	1439-6319
Identifiers:	Number Type 10.1007/s00421-016-3506-8 DOI 3506 Publisher Item Identifier
Rights:	© The author(s) 2016. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Record created by:	Jonathan Gallacher
Date Added:	13 Jul 2018 11:05
Last Modified:	13 Jul 2018 11:06
URI:	https://irep.ntu.ac.uk/id/eprint/34075

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