Model representation of the nonlinear step response in cardiac muscle

• DOI: 10.1085/jgp.201010467
• Publication Date: 2010-07-26T19:07:41Z
• Authors: Steven J. Ford; Murali Chandra; Ranganath Mamidi; Wenji Dong; Kenneth B. Campbell
• Keywords: Cardiac muscle; Distortion (music); Constant (computer programming); Cardiac cycle

Motivated by the need for an analytical tool that can be used routinely to analyze data collected from isolated, detergent-skinned cardiac muscle fibers, we developed a mathematical model representing force response step changes in length (i.e., quick stretch and release). Our proposed is reasonably simple, consisting of only five parameters representing: (1) rate constant which change–induced distortion elastic elements dissipated; (2) stiffness fiber; (3) amplitude length-mediated recruitment elements; (4) this takes place; (5) magnitude nonlinear interaction term affects number recruited elements. Fitting family recordings responses eight amplitudes change (±2.0% baseline 0.5% increments) enabled four things: reproduction all identifiable features seen both positive negative changes; close fitting records whole these with very little residual error; estimation great degree certainty; importantly, ready discrimination between fibers different contractile regulatory proteins but showing subtly function. We recommend as analytic routine use studies fiber Such model-based analysis gives novel insight behavior it useful characterizing mechanistic effects alterations have on