Mechanoelectric feedback in cardiomyocyte monolayers and whole hearts in response to stretch

Stretch has been shown to induce electrophysiological changes in the whole heart and cardiomyocyte monolayer models. However, the mechano-electric mechanisms responsible for these changes are still not completely understood. In this project, micropatterned cardiomyocyte monolayers were anisotropically stretched in order to investigate two hypotheses: the increase in action potential duration (APD) and decrease in conduction velocity (CV) in response to stretch and the effect of stretch-activated channel blockers on these electrophysiological changes. The results obtained showed a decrease in APD in response to stretch in all experiments. Regarding CV, a decrease during propagation in the longitudinal direction (along the long axis of the aligned cardiomyocytes) and an increase during propagation in the transverse direction (along the short axis of the aligned cardiomyocytes) were observed in response to stretch. These electrophysiological changes did not seem altered by the presence of 70 μM and 85 μM streptomycin. However, the results for the APD have to be considered with caution due to limitations of the data analysis procedure