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Evaluation of excitation propagation in the rabbit heart: optical mapping and transmural microelectrode recordings.

Mačianskienė R, Martišienė I, Navalinskas A, Vosyliūtė R, Treinys R, Vaidelytė B, Benetis R, Jurevičius J - PLoS ONE (2015)

Bottom Line: Because of the optical features of heart tissue, optical and electrical action potentials are only moderately associated, especially when near-infrared dyes are used in optical mapping (OM) studies.These components correspond to the components of the propagating electrical wave that are transmural and parallel to the epicardium.The co-registration of OM and transmural microelectrode APs enabled the probing depth of fluorescence measurements to be calculated and the OAP upstroke to be divided into two components (depth-weighted and lateral-scattering), and it also allowed the relative strengths of their effects on the shape of the OAP upstroke to be evaluated.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.

ABSTRACT

Background: Because of the optical features of heart tissue, optical and electrical action potentials are only moderately associated, especially when near-infrared dyes are used in optical mapping (OM) studies.

Objective: By simultaneously recording transmural electrical action potentials (APs) and optical action potentials (OAPs), we aimed to evaluate the contributions of both electrical and optical influences to the shape of the OAP upstroke.

Methods and results: A standard glass microelectrode and OM, using an near-infrared fluorescent dye (di-4-ANBDQBS), were used to simultaneously record transmural APs and OAPs in a Langendorff-perfused rabbit heart during atrial, endocardial, and epicardial pacing. The actual profile of the transmural AP upstroke across the LV wall, together with the OAP upstroke, allowed for calculations of the probing-depth constant (k ~2.1 mm, n = 24) of the fluorescence measurements. In addition, the transmural AP recordings aided the quantitative evaluation of the influences of depth-weighted and lateral-scattering components on the OAP upstroke. These components correspond to the components of the propagating electrical wave that are transmural and parallel to the epicardium. The calculated mean values for the depth-weighted and lateral-scattering components, whose sum comprises the OAP upstroke, were (in ms) 10.18 ± 0.62 and 0.0 ± 0.56 for atrial stimulation, 9.37 ± 1.12 and 3.01 ± 1.30 for endocardial stimulation, and 6.09 ± 0.79 and 8.16 ± 0.98 for epicardial stimulation; (n = 8 for each). For this dye, 90% of the collected fluorescence originated up to 4.83 ± 0.18 mm (n = 24) from the epicardium.

Conclusions: The co-registration of OM and transmural microelectrode APs enabled the probing depth of fluorescence measurements to be calculated and the OAP upstroke to be divided into two components (depth-weighted and lateral-scattering), and it also allowed the relative strengths of their effects on the shape of the OAP upstroke to be evaluated.

No MeSH data available.


Related in: MedlinePlus

Transmural detection of electrical APs in the LV.(A-C) Transmural microelectrode recordings of the AP activation time at various depths during atrial/endocardial/epicardial pacing. (D-F) Superimposition of upstrokes: OAP (light gray line), subendo-AP (black line), epi-AP (gray line), and TAP (solid dotted line). The OAP and TAP were normalized. Note that the TAP does not coincide with the OAP. The data for this figure were obtained from the same experiments described in Fig 2.
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pone.0123050.g003: Transmural detection of electrical APs in the LV.(A-C) Transmural microelectrode recordings of the AP activation time at various depths during atrial/endocardial/epicardial pacing. (D-F) Superimposition of upstrokes: OAP (light gray line), subendo-AP (black line), epi-AP (gray line), and TAP (solid dotted line). The OAP and TAP were normalized. Note that the TAP does not coincide with the OAP. The data for this figure were obtained from the same experiments described in Fig 2.

Mentions: Fig 3A–3C shows the change in the activation time of the APs as a function of depth in the LV wall for stimulations from the atrium, the endocardium, and the epicardium. In each experiment, 30 to 74 original AP recordings (48 on average) from different depths but separate cells in the LV wall, between two surfaces (epicardial/subendocardial), with spacings of 94.6 ± 11.3 μm, 116.5 ± 20.6 μm and 117.8 ± 19.7 μm for atrial, endocardial, and epicardial pacings, respectively, were obtained (n = 8 for each). From the shapes of these curves, we can suggest that the electrical wave propagation in the LV tissue is more or less non-uniform, possibly because of the influence of various morphological structures [10,22].


Evaluation of excitation propagation in the rabbit heart: optical mapping and transmural microelectrode recordings.

Mačianskienė R, Martišienė I, Navalinskas A, Vosyliūtė R, Treinys R, Vaidelytė B, Benetis R, Jurevičius J - PLoS ONE (2015)

Transmural detection of electrical APs in the LV.(A-C) Transmural microelectrode recordings of the AP activation time at various depths during atrial/endocardial/epicardial pacing. (D-F) Superimposition of upstrokes: OAP (light gray line), subendo-AP (black line), epi-AP (gray line), and TAP (solid dotted line). The OAP and TAP were normalized. Note that the TAP does not coincide with the OAP. The data for this figure were obtained from the same experiments described in Fig 2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400155&req=5

pone.0123050.g003: Transmural detection of electrical APs in the LV.(A-C) Transmural microelectrode recordings of the AP activation time at various depths during atrial/endocardial/epicardial pacing. (D-F) Superimposition of upstrokes: OAP (light gray line), subendo-AP (black line), epi-AP (gray line), and TAP (solid dotted line). The OAP and TAP were normalized. Note that the TAP does not coincide with the OAP. The data for this figure were obtained from the same experiments described in Fig 2.
Mentions: Fig 3A–3C shows the change in the activation time of the APs as a function of depth in the LV wall for stimulations from the atrium, the endocardium, and the epicardium. In each experiment, 30 to 74 original AP recordings (48 on average) from different depths but separate cells in the LV wall, between two surfaces (epicardial/subendocardial), with spacings of 94.6 ± 11.3 μm, 116.5 ± 20.6 μm and 117.8 ± 19.7 μm for atrial, endocardial, and epicardial pacings, respectively, were obtained (n = 8 for each). From the shapes of these curves, we can suggest that the electrical wave propagation in the LV tissue is more or less non-uniform, possibly because of the influence of various morphological structures [10,22].

Bottom Line: Because of the optical features of heart tissue, optical and electrical action potentials are only moderately associated, especially when near-infrared dyes are used in optical mapping (OM) studies.These components correspond to the components of the propagating electrical wave that are transmural and parallel to the epicardium.The co-registration of OM and transmural microelectrode APs enabled the probing depth of fluorescence measurements to be calculated and the OAP upstroke to be divided into two components (depth-weighted and lateral-scattering), and it also allowed the relative strengths of their effects on the shape of the OAP upstroke to be evaluated.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.

ABSTRACT

Background: Because of the optical features of heart tissue, optical and electrical action potentials are only moderately associated, especially when near-infrared dyes are used in optical mapping (OM) studies.

Objective: By simultaneously recording transmural electrical action potentials (APs) and optical action potentials (OAPs), we aimed to evaluate the contributions of both electrical and optical influences to the shape of the OAP upstroke.

Methods and results: A standard glass microelectrode and OM, using an near-infrared fluorescent dye (di-4-ANBDQBS), were used to simultaneously record transmural APs and OAPs in a Langendorff-perfused rabbit heart during atrial, endocardial, and epicardial pacing. The actual profile of the transmural AP upstroke across the LV wall, together with the OAP upstroke, allowed for calculations of the probing-depth constant (k ~2.1 mm, n = 24) of the fluorescence measurements. In addition, the transmural AP recordings aided the quantitative evaluation of the influences of depth-weighted and lateral-scattering components on the OAP upstroke. These components correspond to the components of the propagating electrical wave that are transmural and parallel to the epicardium. The calculated mean values for the depth-weighted and lateral-scattering components, whose sum comprises the OAP upstroke, were (in ms) 10.18 ± 0.62 and 0.0 ± 0.56 for atrial stimulation, 9.37 ± 1.12 and 3.01 ± 1.30 for endocardial stimulation, and 6.09 ± 0.79 and 8.16 ± 0.98 for epicardial stimulation; (n = 8 for each). For this dye, 90% of the collected fluorescence originated up to 4.83 ± 0.18 mm (n = 24) from the epicardium.

Conclusions: The co-registration of OM and transmural microelectrode APs enabled the probing depth of fluorescence measurements to be calculated and the OAP upstroke to be divided into two components (depth-weighted and lateral-scattering), and it also allowed the relative strengths of their effects on the shape of the OAP upstroke to be evaluated.

No MeSH data available.


Related in: MedlinePlus