Quantification of cardiomyocyte contraction based on image correlation analysis

Abstract

Quantification of cardiomyocyte contraction is usually obtained by measuring globally cell shortening from the displacement of cell extremities. We developed a correlationbased optical flow method, which correlates the whole-cell temporal pattern with a precise quantification of the intracellular strain wave at the sarcomeres level. A two-dimensional image correlation analysis of cardiomyocytes phase-contrast images was developed to extract local cell deformations from videomicroscopy time-lapse sequences. Test images, synthesized from known intensity displacement fields, were first used to validate the method. Intracellular strain fields were then computed from videomicroscopy time-lapse sequences of single adult and neonatal cardiomyocytes. The propagation of the sarcomeres contraction-relaxation wave during cell contraction has been successfully quantified. The time-varying patterns of intracellular displacement were obtained accurately, even when cardiomyocyte bending occurred in pace with contraction. Interestingly, the characterization of the successive 2D displacement fields show a direct quantification of the variation with time of intracellular strains anywhere in the cell. The proposed method enables a quantitative analysis of cardiomyocyte contraction without requiring wave tracking with the use of fluorescent calcium probes. Thus, our algorithmic approach provides a fast and efficient tool for analyzing the correlation between global cell dynamical behavior and mechanosensitive intracellular processes.

An integrated formulation of anisotropic force–calcium relations driving spatio-temporal contractions of cardiac myocytes

“…A number of advances in experimental techniques, including the extended use of Ca 2+ probes coupled with confocal or total internal reflection fluorescence microscopy (Blatter et al 2003;Bai et al 2008;Alonso et al 2009), together with adapted digital image processing (Kamgoue et al 2009) have promoted an accurate analysis of intracellular Ca 2+ wave dynamics and cardiac cell contractions. Along with these developments, simulation studies have provided significant contributions to the understanding of the complexity of the excitationcontraction process that drives and regulates the mechanical behaviour of cardiac myocytes.…”

Lipid Emulsion Rapidly Restores Contractility in Stunned Mouse Cardiomyocytes

“…Speckle Image Velocimetry (24) was used to quantify contraction velocity with custom written MATLAB software (Mathworks, Natick MA). Speckle image velocimetry method was similar to previously described methods (25) and focused on contractions of the entire collection of neonatal cardiomyocytes in a microscopic field as opposed to velocities within a single adult myocyte (26, 27). In brief: A 19×19 array of 30×30 pixel (24×24 microns) windows to be tracked were spaced 25 pixels (20 microns) apart for reliable tracking of windows across contractions.…”

A Three-dimensional Continuum Model of Active Contraction in Single Cardiomyocytes

“…Movement with respect to the principal direction f 0 and bending are expected in realistic scenarios [9]. Finally we compare our cases with the study reported in [28] in terms of contractility patterns of the cell ends (see also [31]). Our results (for pure Robin boundary data) show a reasonable qualitative agreement, considering that the cell shapes do not coincide (see Fig.…”