Cardiac electrophysiological imaging systems scalable for high-throughput drug testing

Area of Science:

• Cardiac Electrophysiology
• Optical Imaging Techniques
• Cardiovascular Pharmacology

Background:

• Multi-parametric electrophysiological measurements using optical methods are crucial in cardiac research.
• Existing optical mapping systems are often expensive and complex, limiting accessibility.
• Simpler, more affordable solutions are needed for various cardiac research applications.

Purpose of the Study:

• To describe and validate two simplified optical mapping systems for cardiac voltage and calcium imaging.
• To demonstrate the utility of an economy electron-multiplying charge-coupled device camera and consumer cameras for cardiac imaging.
• To showcase a photodiode-based system for high temporal resolution measurements.
• To assess the systems' applicability in high-throughput drug testing using a relevant cardiovascular drug.

Main Methods:

• Development of a camera-based voltage and calcium imaging system using an economy electron-multiplying charge-coupled device camera.
• Construction of a photodiode-based system with optical fibers for high temporal resolution voltage and calcium measurements.
• Application of the developed systems to Langendorff-perfused whole-heart and thin ventricular tissue slices.
• Testing the systems' response to nifedipine, a calcium channel blocker, to evaluate drug effects.

Main Results:

• Demonstrated the feasibility of using an economy CCD camera and consumer cameras for cardiac calcium transient imaging.
• Successfully implemented a high temporal resolution photodiode-based system for simultaneous voltage and calcium measurements.
• Observed marked changes in voltage and calcium transients in response to nifedipine exposure.
• Validated the systems' capability to monitor drug-induced electrophysiological effects in cardiac tissue models.

Conclusions:

• Simplified, cost-effective optical mapping systems can be effectively utilized in cardiac research.
• These systems are suitable for simultaneous voltage and calcium transient measurements, including high-throughput drug screening.
• The developed methods provide valuable tools for studying cardiac electrophysiology and the effects of cardiovascular drugs.