Reduced preload increases Mechanical Control (strain-rate dependence) of Relaxation by modifying myosin kinetics.

ABSTRACT: Rapid myocardial relaxation is essential in maintaining cardiac output, and impaired relaxation is an early indicator of diastolic dysfunction. While the biochemical modifiers of relaxation are well known to include calcium handling, thin filament activation, and myosin kinetics, biophysical and biomechanical modifiers can also alter relaxation. We have previously shown that the relaxation rate is increased by an increasing strain rate, not a reduction in afterload. The slope of the relaxation rate to strain rate relationship defines Mechanical Control of Relaxation (MCR). To investigate MCR further, we performed in vitro experiments and computational modeling of preload-adjustment using intact rat cardiac trabeculae. Trabeculae studies are often performed using isometric (fixed-end) muscl

SUBMITTER: Schick BM 

PROVIDER: S-EPMC8635462 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature