Optical mapping of contracting hearts

Kappadan, Vineesh; Sohi, Anies; Parlitz, Ulrich; Uzelac, Ilija; Fenton, Flavio H.; Peters, Nicholas S.; Christoph, Jan; Ng, Fu Siong

doi:10.1113/jp283683

Cited by 7 publications

(7 citation statements)

References 79 publications

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“… 35 Furthermore ratiometric dyes, including voltage-sensitive dyes, 36 can significantly mitigate system noise and motion artefacts (see Motion tracking section). 37 …”

Section: Principles Of Optical Mappingmentioning

confidence: 99%

“…Motion tracking by computational signal correction or ratiometry has made it possible to optically map the freely beating heart. 37 , 66 Markers can be used to track and correct for movement. 67 Motion correction can also be achieved without the use of fiducial markers, for example, by optical flow methods, which compute displacement vectors to quantify pixel movement and motion.…”

Section: Principles Of Optical Mappingmentioning

confidence: 99%

“…However, ratiometry alone does not ensure spatial coupling, so can only be used in preparations with minimal dispersion. 37 There are also inherent limitations, including reduced effective frame rates. Several studies have combined motion tracking, ratiometry techniques and tracking images within each spectral band for further reduction in motion artefacts.…”

Section: Principles Of Optical Mappingmentioning

confidence: 99%

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Optical mapping and optogenetics in cardiac electrophysiology research and therapy: a state-of-the-art review

Baines,

Sha,

Kalla

et al. 2024

Europace

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State-of-the-art innovations in optical cardiac electrophysiology are significantly enhancing cardiac research. A potential leap into patient care is now on the horizon. Optical mapping, using fluorescent probes and high-speed cameras, offers detailed insights into cardiac activity and arrhythmias by analysing electrical signals, calcium dynamics, and metabolism. Optogenetics utilises light-sensitive ion channels and pumps to realise contactless, cell-selective cardiac actuation for modelling arrhythmia, restoring sinus rhythm, and probing complex cell-cell interactions. The merging of optogenetics and optical mapping techniques for ‘all-optical’ electrophysiology marks a significant step forward. This combination allows for the contactless actuation and sensing of cardiac electrophysiology, offering unprecedented spatial-temporal resolution and control. Recent studies have performed all-optical imaging ex vivo and achieved reliable optogenetic pacing in vivo, narrowing the gap for clinical use. Progress in optical electrophysiology continues at pace. Advances in motion tracking methods are removing the necessity of motion uncoupling, a key limitation of optical mapping. Innovations in optoelectronics, including miniaturised, biocompatible illumination and circuitry, are enabling the creation of implantable cardiac pacemakers and defibrillators with optoelectrical closed-loop systems. Computational modelling and machine learning are emerging as pivotal tools in enhancing optical techniques, offering new avenues for analysing complex data and optimising therapeutic strategies. However, key challenges remain including opsin delivery, real-time data processing, longevity and chronic effects of optoelectronic devices. This review provides a comprehensive overview of recent advances in optical mapping and optogenetics and outlines the promising future of optics in reshaping cardiac electrophysiology and therapeutic strategies.

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“… 35 Furthermore ratiometric dyes, including voltage-sensitive dyes, 36 can significantly mitigate system noise and motion artefacts (see Motion tracking section). 37 …”

Section: Principles Of Optical Mappingmentioning

confidence: 99%

Section: Principles Of Optical Mappingmentioning

confidence: 99%

Section: Principles Of Optical Mappingmentioning

confidence: 99%

See 1 more Smart Citation

Optical mapping and optogenetics in cardiac electrophysiology research and therapy: a state-of-the-art review

Baines,

Sha,

Kalla

et al. 2024

Europace

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show abstract

“…Intact heart preparations were allowed to equilibrate for 10-20 minutes on the perfusion system. Once the heart was stabilized, (-/-) blebbistatin (rat heart: 8.5 µM, guinea pig heart: 12.8 µM) was added to the perfusate to reduce metabolic demand and suppress contractile motion [17][18][19] .…”

Section: Isolated Heart Preparation and Langendorff-perfusionmentioning

confidence: 99%

KairoSight-3.0: A Validated Optical Mapping Software to Characterize Cardiac Electrophysiology, Excitation-Contraction Coupling, and Alternans

Haq

Roberts

Berk

et al. 2023

Preprint

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Background: Cardiac optical mapping is an imaging technique that measures fluorescent signals across a cardiac preparation. Dual optical mapping of voltage-sensitive and calcium-sensitive probes allow for simultaneous recordings of cardiac action potentials and intracellular calcium transients with high spatiotemporal resolution. The analysis of these complex optical data sets re both time intensive and technically challenging; as such, we have developed a software package for semi-automated image processing and analysis. Herein, we report an updated version of our software package (KairoSight-3.0) with updated features to fully characterize cardiac parameters using optical signals. Methods: To collect datasets to test software validity and applicability, we used Langendorff-perfused heart preparations to record transmembrane voltage and intracellular calcium signals from the epicardial surface. Isolated hearts from guinea pigs and rats were loaded with a potentiometric dye (RH237) and/or calcium indicator dye (Rhod-2AM) and fluorescent signals were acquired. We used Python 3.8.5 programming language to develop the KairoSight-3.0 software. Cardiac maps were validated with a user-specified manual mapping approach using MATLAB scripts. Results: Manual maps of action potential duration (30 or 80% repolarization), calcium transient duration (30 or 80% reuptake), action potential and calcium transient alternans were constituted to validate the accuracy of software-generated maps. Manual and software maps had high accuracy, with >97% of manual and software values falling within 10 ms of each other and >75% within 5 ms for action potential duration and calcium transient duration measurements (n=1000-2000 pixels). Further, our software package includes additional cardiac metric measurement tools to analyze signal-to-noise ratio, conduction velocity, action potential and calcium transient alternans, and action potential-calcium transient coupling time to produce physiologically meaningful optical maps. Conclusions: KairoSight-3.0 has enhanced capabilities to perform measurements of cardiac electrophysiology, calcium handling, and the excitation-contraction coupling with satisfactory accuracy.

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“…In another recent article, theoretical models of optogenetic control of cardiac myocytes were used for design optimization and technological enhancement (Pyari et al., 2022). Along these lines, a recent review discusses how recent developments in computer vision algorithms and ratiometric techniques might be employed to overcome the limitations of conventional optical mapping with non‐contracting hearts (Kappadan et al., 2023). These novel approaches have the potential to provide valuable insight into the intricate mechanisms involved in mechano–electrical coupling.…”

mentioning

confidence: 99%