KairoSight-3.0: A validated optical mapping software to characterize cardiac electrophysiology, excitation-contraction coupling, and alternans

Haq, Kazi T.; Roberts, Anysja; Berk, Fiona; Allen, Samuel; Swift, Luther M.; Posnack, Nikki Gillum

doi:10.1016/j.jmccpl.2023.100043

Cited by 5 publications

(10 citation statements)

References 53 publications

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“…However, to date, there is limited information on ECC in the context of the intact heart. Using our previously described methodology 26 , we generated action potential-calcium transient (AP-CaT) latency maps using optical signals collected from guinea pig hearts. As shown in Figure 8A , latency maps from adult hearts reveal negative coupling (APD30 > CaD30) during early repolarization and positive coupling (APD70 < CaD70) during late repolarization.…”

Section: Resultsmentioning

confidence: 99%

“…Based on our prior work 23–26 , we established a set of exclusion criteria to minimize the impact of experimental factors on outcome measurements. Animals were excluded from in-vivo ECG analyses if: The heart rate changed sharply within 2 minutes of recording, possibly due to inadequate anesthetic response. ECG recording had a poor signal-to-noise ratio. Animals were excluded from heart weight analysis if the measured value was identified as an outlier using statistical analysis.…”

Section: Methodsmentioning

confidence: 99%

“…Fluorescence signals were analyzed and optical maps were generated using Kairosight-3.0 26 . Activation maps (representing the time of maximum slope of the AP upstroke (dF/dt max )) were generated and CV was calculated to characterize epicardial AP activation in the ventricles.…”

Section: Methodsmentioning

confidence: 99%

“…Similarly, CaD was calculated as the difference between the maximum slope of the CaT upstroke (dF/dt max ) to specific phases of CaT decay (30%, 50%, and 70%). The latency between AP repolarization and CaT decay was also determined at each pixel, as previously described 26 . To reveal restitution characteristics, dynamic (S1-S1) and extrasystolic (S1-S2) pacing was applied to the ventricular apex using different pacing cycle lengths (PCL).…”

Section: Methodsmentioning

confidence: 99%

“…Based on our prior work [23][24][25][26] , we established a set of exclusion criteria to minimize the impact of experimental factors on outcome measurements.  ECG recording had a poor signal-to-noise ratio.…”

Section: Exclusion Criteriamentioning

confidence: 99%

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Electroanatomical Adaptations in the Guinea Pig Heart from Neonatal to Adulthood

Haq,

McLean,

Salameh

et al. 2024

Preprint

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Background: Electroanatomical adaptations during the neonatal to adult phase have not been comprehensively studied in preclinical animal models. To explore the impact of age as a biological variable on cardiac electrophysiology, we employed neonatal and adult guinea pigs, which are a recognized animal model for developmental research. Methods: Healthy guinea pigs were categorized into three age groups (neonates, n=10; younger adults, n=13; and older adults, n=26). Electrocardiogram (ECG) recordings were collected in vivo from anesthetized animals (2-3% isoflurane). A Langendorff-perfusion system was employed for optical assessment of epicardial action potentials and calcium transients, using intact excised heart preparations. Optical data sets were analyzed and metric maps were constructed using Kairosight 3.0. Results: The allometric relationship between heart weight and body weight diminishes with age, as it is strongest at the neonatal stage (R2 = 0.84) and completely abolished in older adults (R2 = 1E06). Neonatal hearts exhibit circular activation waveforms, while adults show prototypical elliptical shapes. Neonatal conduction velocity (40.6 +/- 4.0 cm/s) is slower than adults (younger adults: 61.6 +/- 9.3 cm/s; older adults: 53.6 +/- 9.2 cm/s). Neonatal hearts have a longer action potential duration (APD) and exhibit regional heterogeneity (left apex; APD30: 68.6 +/- 5.6 ms, left basal; APD30: 62.8 +/- 3.6), which was absent in adult epicardium. With dynamic pacing, neonatal hearts exhibit a flatter APD restitution slope (APD70: 0.29 +/- 0.04) compared to older adults (0.49 +/- 0.04). Similar restitution characteristics are observed with extrasystolic pacing, with a flatter slope in neonatal hearts (APD70: 0.54 +/- 0.1) compared to adults (Younger adults: 0.85 +/- 0.4 ; Older adults: 0.95 +/- 0.7). Finally, neonatal hearts display unidirectional excitation-contraction coupling, while adults exhibit bidirectionality. Conclusion: The transition from neonatal to adulthood in guinea pig hearts is characterized by transient changes in electroanatomic properties. Age-specific patterns can influence cardiac physiology, pathology, and therapies for cardiovascular diseases. Understanding postnatal heart development is crucial to evaluating therapeutic eligibility, safety, and efficacy.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Exclusion Criteriamentioning

confidence: 99%

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Electroanatomical Adaptations in the Guinea Pig Heart from Neonatal to Adulthood

Haq,

McLean,

Salameh

et al. 2024

Preprint

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Evaluation of novel open-source software for cardiac optical mapping

Baines,

Sha,

Jatti

et al. 2024

Journal of Molecular and Cellular Cardiology Plus

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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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KairoSight-3.0: A validated optical mapping software to characterize cardiac electrophysiology, excitation-contraction coupling, and alternans

Cited by 5 publications

References 53 publications

Electroanatomical Adaptations in the Guinea Pig Heart from Neonatal to Adulthood

Electroanatomical Adaptations in the Guinea Pig Heart from Neonatal to Adulthood

Evaluation of novel open-source software for cardiac optical mapping

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

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