The forward problem in optical mapping of electrical activity in the heart: application to various imaging methods

2005 ◽  
Author(s):  
Olivier Bernus ◽  
Vadim D. Khait ◽  
Marcel Wellner ◽  
Sergey F. Mironov ◽  
Arkady M. Pertsov
Keyword(s):  
Electrical Activity ◽  
Optical Mapping ◽  
Forward Problem ◽  
Imaging Methods

scholarly journals Optical mapping of the electrical activity of isolated adult zebrafish hearts: acute effects of temperature

2014 ◽  
Vol 306 (11) ◽  
pp. R823-R836 ◽  
Author(s):  
Eric Lin ◽  
Amanda Ribeiro ◽  
Weiguang Ding ◽  
Leif Hove-Madsen ◽  
Marinko V. Sarunic ◽  
...  
Keyword(s):  
Action Potential ◽  
Electrical Activity ◽  
Cardiac Electrophysiology ◽  
Optical Mapping ◽  
Cooling System ◽  
Effect Of Temperature ◽  
Adult Zebrafish ◽  
Depth Analysis ◽  
Zebrafish Heart ◽  
Av Delay

The zebrafish ( Danio rerio) has emerged as an important model for developmental cardiovascular (CV) biology; however, little is known about the cardiac function of the adult zebrafish enabling it to be used as a model of teleost CV biology. Here, we describe electrophysiological parameters, such as heart rate (HR), action potential duration (APD), and atrioventricular (AV) delay, in the zebrafish heart over a range of physiological temperatures (18–28°C). Hearts were isolated and incubated in a potentiometric dye, RH-237, enabling electrical activity assessment in several distinct regions of the heart simultaneously. Integration of a rapid thermoelectric cooling system facilitated the investigation of acute changes in temperature on critical electrophysiological parameters in the zebrafish heart. While intrinsic HR varied considerably between fish, the ex vivo preparation exhibited impressively stable HRs and sinus rhythm for more than 5 h, with a mean HR of 158 ± 9 bpm (means ± SE; n = 20) at 28°C. Atrial and ventricular APDs at 50% repolarization (APD50) were 33 ± 1 ms and 98 ± 2 ms, respectively. Excitation originated in the atrium, and there was an AV delay of 61 ± 3 ms prior to activation of the ventricle at 28°C. APD and AV delay varied between hearts beating at unique HRs; however, APD and AV delay did not appear to be statistically dependent on intrinsic basal HR, likely due to the innate beat-to-beat variability within each heart. As hearts were cooled to 18°C (by 1°C increments), HR decreased by ∼40%, and atrial and ventricular APD50 increased by a factor of ∼3 and 2, respectively. The increase in APD with cooling was disproportionate at different levels of repolarization, indicating unique temperature sensitivities for ion currents at different phases of the action potential. The effect of temperature was more apparent at lower levels of repolarization and, as a whole, the atrial APD was the cardiac parameter most affected by acute temperature change. In conclusion, this study describes a preparation enabling the in-depth analysis of transmembrane potential dynamics in whole zebrafish hearts. Because the zebrafish offers some critical advantages over the murine model for cardiac electrophysiology, optical mapping studies utilizing zebrafish offer insightful information into the understanding and treatment of human cardiac arrhythmias, as well as serving as a model for other teleosts.

scholarly journals Stop the beat to see the rhythm: excitation-contraction uncoupling in cardiac research

2021 ◽  
Author(s):  
Luther M. Swift ◽  
Matthew W. Kay ◽  
Crystal M. Ripplinger ◽  
Nikki Gillum Posnack
Keyword(s):  
Electrical Activity ◽  
Cardiac Electrophysiology ◽  
Cardiac Tissue ◽  
Optical Mapping ◽  
Myocardial Contraction ◽  
Motion Artifacts ◽  
Secondary Effects ◽  
Metabolic Demand ◽  
Cardiovascular Research ◽  
Fluorescent Indicators

Optical mapping is an imaging technique that is extensively used in cardiovascular research, wherein parameter-sensitive fluorescent indicators are used to study the electrophysiology and excitation-contraction coupling of cardiac tissues. Despite the many benefits of optical mapping, eliminating motion artifacts within the optical signals is a major challenge, as myocardial contraction interferes with the faithful acquisition of action potentials and intracellular calcium transients. As such, excitation-contraction uncoupling agents are frequently used to reduce signal distortion by suppressing contraction. Compared to other uncoupling agents, blebbistatin is the most frequently used as it offers increased potency with minimal direct effects on cardiac electrophysiology. Nevertheless, blebbistatin may exert secondary effects on electrical activity, metabolism, and coronary flow, and the incorrect administration of blebbistatin to cardiac tissue can prove detrimental, resulting in erroneous interpretation of optical mapping results. In this "Getting It Right" perspective, we briefly review the literature regarding the use of blebbistatin in cardiac optical mapping experiments, highlight potential secondary effects of blebbistatin on cardiac electrical activity and metabolic demand, and conclude with the consensus of the authors on best practices for effectively using blebbistatin in optical mapping studies of cardiac tissue.

Image-Based Motion Correction for Optical Mapping of Cardiac Electrical Activity

2014 ◽  
Vol 43 (5) ◽  
pp. 1235-1246 ◽  
Author(s):  
Prashanna Khwaounjoo ◽  
Sally L. Rutherford ◽  
Martin Svrcek ◽  
Ian J. LeGrice ◽  
Mark L. Trew ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Motion Correction ◽  
Optical Mapping ◽  
Cardiac Electrical Activity

scholarly journals Optical mapping of human embryonic stem cell-derived cardiomyocyte graft electrical activity in injured hearts

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dominic Filice ◽  
Wahiba Dhahri ◽  
Joell L. Solan ◽  
Paul D. Lampe ◽  
Erin Steele ◽  
...  
Keyword(s):  
Stem Cell ◽  
Electrical Activity ◽  
Embryonic Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Optical Mapping ◽  
Embryonic Stem ◽  
Water Soluble ◽  
Voltage Sensitive Dye ◽  
Simultaneous Imaging ◽  
Voltage Mapping

Abstract Background Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) show tremendous promise for cardiac regeneration, but the successful development of hESC-CM-based therapies requires improved tools to investigate their electrical behavior in recipient hearts. While optical voltage mapping is a powerful technique for studying myocardial electrical activity ex vivo, we have previously shown that intra-cardiac hESC-CM grafts are not labeled by conventional voltage-sensitive fluorescent dyes. We hypothesized that the water-soluble voltage-sensitive dye di-2-ANEPEQ would label engrafted hESC-CMs and thereby facilitate characterization of graft electrical function and integration. Methods We developed and validated a novel optical voltage mapping strategy based on the simultaneous imaging of the calcium-sensitive fluorescent protein GCaMP3, a graft-autonomous reporter of graft activation, and optical action potentials (oAPs) derived from di-2-ANEPEQ, which labels both graft and host myocardium. Cardiomyocytes from three different GCaMP3+ hESC lines (H7, RUES2, or ESI-17) were transplanted into guinea pig models of subacute and chronic infarction, followed by optical mapping at 2 weeks post-transplantation. Results Use of a water-soluble voltage-sensitive dye revealed pro-arrhythmic properties of GCaMP3+ hESC-CM grafts from all three lines including slow conduction velocity, incomplete host-graft coupling, and spatially heterogeneous patterns of activation that varied beat-to-beat. GCaMP3+ hESC-CMs from the RUES2 and ESI-17 lines both showed prolonged oAP durations both in vitro and in vivo. Although hESC-CMs partially remuscularize the injured hearts, histological evaluation revealed immature graft structure and impaired gap junction expression at this early timepoint. Conclusion Simultaneous imaging of GCaMP3 and di-2-ANEPEQ allowed us to acquire the first unambiguously graft-derived oAPs from hESC-CM-engrafted hearts and yielded critical insights into their arrhythmogenic potential and line-to-line variation.

scholarly journals Correction to: Optical mapping of human embryonic stem cell-derived cardiomyocyte graft electrical activity in injured hearts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dominic Filice ◽  
Wahiba Dhahri ◽  
Joell L. Solan ◽  
Paul D. Lampe ◽  
Erin Steele ◽  
...  
Keyword(s):  
Stem Cell ◽  
Electrical Activity ◽  
Embryonic Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Optical Mapping ◽  
Embryonic Stem

An amendment to this paper has been published and can be accessed via the original article.

Abstract MP114: Cardiotropic Adenovirus Increases Arrhythmia Susceptibility During Acute Infection

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Rachel L Padget ◽  
D. Ryan King ◽  
Michael D North ◽  
Mira N Tanenbaum ◽  
Patrick J Calhoun ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Electrical Activity ◽  
Ion Channel ◽  
Gap Junction ◽  
Cardiac Death ◽  
Optical Mapping ◽  
Acute Infection ◽  
Intercellular Coupling ◽  
Viral Genomes ◽  
Arrhythmogenic Substrate

Myocarditis is responsible for up to 42% of sudden cardiac death in young adults yet mechanisms underlying virally-induced arrhythmia remain elusive. Adenovirus is a leading etiological agent of myocarditis but due to species-specificity, in vivo models are limited. Altered cardiac gap junction function underlies sudden cardiac death and given that gap junctions also propagate antiviral immune responses, we hypothesized adenovirus would target intercellular coupling, leading to arrhythmogenesis. Employing a recently described strain of mouse adenovirus, MAdV-3, we investigated cardiotropism, arrhythmia susceptibility, and molecular mechanisms of a virally-induced arrhythmogenic substrate. Adult C57BL/6 mice were inoculated with MAdV-3 and infection allowed to progress for one week. Viral genomes were detected by qPCR to measure tissue tropism together with whole animal histopathology. Echo- and electrocardiography were used to measure cardiac function and electrical activity. Viral effects on transcription and junctional protein/ion channel expression and localization were quantified using RT-qPCR, confocal microscopy, and western blotting. Finally, ex vivo optical mapping was employed to test conduction defects and susceptibility to arrhythmia. We find MAdV-3 viral genomes specifically enriched in heart tissue, confirming cardiotropism. Immune cell infiltration was not detected in the heart and no cardiomyopathy was apparent by echocardiography. RR interval widening, however, does occur in MAdV-3 infected mice with reductions in cardiac ion channel and gap junction mRNA transcripts. Optical mapping experiments show that conduction velocity is altered in acutely infected hearts and norepinephrine challenge uncovered electrical impairment presenting as atrioventricular dissociation with increased premature ventricular contraction burden. Our data demonstrate that MAdV-3 is cardiotropic and acute infection result in changes in cardiac electrical activity prior to development of cardiomyopathy or a detectable immune response. MAdV-3 infection is a novel model for adenoviral myocarditis, providing insights into viral subversion of cardiac intercellular coupling and mechanisms of arrhythmogenesis.

scholarly journals -369-REAL-TIME OPTICAL MAPPING OF PROPAGATION OF ELECTRICAL ACTIVITY IN THE BULLFROG ATRIUM

1986 ◽  
Vol 50 (6) ◽  
pp. 570
Author(s):  
Akihiko Hirota ◽  
Tetsuro Sakai ◽  
Hitoshi Komuro ◽  
Kohtaro Kamino
Keyword(s):  
Electrical Activity ◽  
Real Time ◽  
Optical Mapping

DYNAMIC TRANSMURALITY: CARDIAC OPTICAL MAPPING REVEALS WAVES TRAVEL ACROSS TRANSMURAL ABLATION LINES

2007 ◽  
Vol 17 (09) ◽  
pp. 3229-3234
Author(s):  
JENNIFER D. SIMONOTTO ◽  
MICHAEL D. FURMAN ◽  
WILLIAM L. DITTO ◽  
ABRAHAM MILIOTIS ◽  
MARK L. SPANO ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Electrical Activity ◽  
Fluorescence Imaging ◽  
Incident Wave ◽  
Optical Mapping ◽  
Cardiac Ablation ◽  
Porcine Heart ◽  
Complex Propagation

Cardiac ablation is increasingly used to interdict the complex propagation of excitatory waves during atrial fibrillation. While such procedures are useful, they can often fail. Here we use fluorescence imaging to observe the electrical activity of an ablated porcine heart. We find that, while ablation lines do attenuate cardiac waves, the attenuation is incomplete. A remnant of the incident wave survives passage through the ablation barrier, albeit as a subthreshold signal. More importantly, we have found that these subthreshold signals may add constructively and thereby dynamically reduce the effective attenuation, an effect which we call "dynamic transmurality". We suspect this as a factor in the persistence of arrhythmia after ablative.

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