Cardiac inotropy refers to the contractile strength of heart muscle. Positive inotropes strengthen the force of cardiac muscle contractions, and negative inotropes weaken them. Both positive and negative inotropes are used in the management of various cardiovascular conditions. Cardiomyocytes cultured in MEA plates form a spontaneously beating syncytium. As the cardiomyocytes mechanically contract and relax over a recording electrode, the shape change is detected as an increase and decrease in the impedance signal.
The Maestro Pro and Edge systems detect key parameters of cardiomyocyte contractility, including beat amplitude, beat timing, and excitation-contraction delay. Maestro Pro & Edge are the only platforms that allow measurement of cardiomyocyte electrical activity and the resulting contraction on the same electrode, providing a more complete understanding of your cardiac model's functionality.
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Elicit mature force-frequency response>
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Detect inotropic compounds>
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Monitor changes in contractility for 3D cultures>
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Assay Steps>
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are limited by functional immaturity, including immature calcium handling and contractility function. Physical conditioning via electrical or mechanical stimulation facilitates cardiomyocyte maturation as measured by a positive force-frequency relationship.
(A,B) FCDI iCell cardiomyocytes2 (CM2 ) were chronically paced at 2 Hz for 48 hours. (A,B) After chronic pacing, cells were paced at 0.8 up to 3 Hz to assess the force-frequency relationship. Paced wells (orange) exhibited a positive force-frequency relationship after only 48 hours, while non-paced control wells (gray) showed a slight negative relationship. Representative paced (orange) and control (gray) contractility traces are shown at 1 Hz (thin line), 2 Hz, and 3 Hz (thick line).
