Measuring Cardiomyocyte Contractility and Calcium Handling In Vitro.

<div>In vitro measurements of cardiomyocyte contractility and Ca2+ handling have been used as a platform for</div><div>determining physiological consequence of various genetic manipulations and identifying potential therapeutic</div><div>targets for the treatment of heart failure. The Myocyte Calcium and Contractility System (IonOptix)</div><div>offers a simultaneous trace of sarcomere movements and changes of intracellular Ca2+ levels in a single</div><div>cardiomyocyte. Herein, we describe a modified protocol for the isolation of adult cardiomyocytes from</div><div>murine hearts and provide a step-by-step description on how to analyze cardiomyocyte Ca2+ transient and</div><div>contractility data collected using the IonOptix system. In our modified protocol, we recommend a novel</div><div>cannulation technique which simplifies this difficult method and leads to improved viability of isolated</div><div>cardiomyocytes. In addition, a comprehensive analysis of intracellular Ca2+ handling, SR Ca2+ load,</div><div>myofilament Ca2+ sensitivity, and cardiomyocyte contractility is described in order to provide important</div><div>insights into myocardial mechanics.</div>