Papillary Muscle Mechanics
Papillary muscle studies are performed with the CMRG instrumentation and associated application software, Twitch. This same system can be used for measuring Calcium transients in isolated cardiac myocytes, and documentation for this particular use is also covered here. The purpose of the intact papillary muscle mechanics apparatus is to enable measurement of force, the intracellular Ca transient, and muscle segment length (and possibly sarcomere length) all simultaneously. At the same time, changes in muscle length can be administered with precise timing relative to stimulation of the muscle. This allows for detailed characterization of both passive and active cardiac muscle mechanics under a variety of paradigms. The control and measurement systems comprising the apparatus are integrated by a custom Python application, Twitch. Twitch allows the user to easily design and implement protocols. The program then interacts with the apparatus in an automated way to run the protocol and collect data.