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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

Influence of DWTAP and LSCATT on the OAP upstroke.(A-C) Traces of all upstrokes obtained for atrial/endo-/epi-pacing: simultaneous recordings of a subendo-AP (black line), epi-AP (gray line), and an OAP (light gray line) compared with the calculated TAP (dot line) and DWTAP (dashed line) signals. (D-F) Comparison of the OAP and DWTAP (same as in A-C). The difference between these signals provided the LSCATT (gray area); for better visualization, this LSCATT is also shown along the x-axis (dashed area).Note that a positive peak and a negative peak indicate an oncoming and receding wave, respectively, induced by LSCATT only when stimulated at the endo- or epicardium but not when stimulated at the atrium. DWTAP and LSCATT coexist around the mid-part of the OAP upstroke.
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pone.0123050.g004: Influence of DWTAP and LSCATT on the OAP upstroke.(A-C) Traces of all upstrokes obtained for atrial/endo-/epi-pacing: simultaneous recordings of a subendo-AP (black line), epi-AP (gray line), and an OAP (light gray line) compared with the calculated TAP (dot line) and DWTAP (dashed line) signals. (D-F) Comparison of the OAP and DWTAP (same as in A-C). The difference between these signals provided the LSCATT (gray area); for better visualization, this LSCATT is also shown along the x-axis (dashed area).Note that a positive peak and a negative peak indicate an oncoming and receding wave, respectively, induced by LSCATT only when stimulated at the endo- or epicardium but not when stimulated at the atrium. DWTAP and LSCATT coexist around the mid-part of the OAP upstroke.

Mentions: Fig 4A–4C shows the upstroke shapes in detail for APs obtained for three different types of pacing. When stimulated from the atrium, the DWTAP and OAP upstrokes highly coincided because under such experimental conditions, LSCATT is almost negligible (Fig 4D). However, as shown in Fig 4E and 4F, during endo-/epicardial stimulation, the calculated DWTAP upstrokes were still not equivalent to OAP. This finding indicates that the remaining part (Fig 4E and 4F, gray area or shaded area) of the OAP upstroke could be attributed to LSCATT. The largest difference between the OAP upstroke and DWTAP was obtained during the epi-pacing, apparently because a large lateral-scattering component occurred under such circumstances.


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)

Influence of DWTAP and LSCATT on the OAP upstroke.(A-C) Traces of all upstrokes obtained for atrial/endo-/epi-pacing: simultaneous recordings of a subendo-AP (black line), epi-AP (gray line), and an OAP (light gray line) compared with the calculated TAP (dot line) and DWTAP (dashed line) signals. (D-F) Comparison of the OAP and DWTAP (same as in A-C). The difference between these signals provided the LSCATT (gray area); for better visualization, this LSCATT is also shown along the x-axis (dashed area).Note that a positive peak and a negative peak indicate an oncoming and receding wave, respectively, induced by LSCATT only when stimulated at the endo- or epicardium but not when stimulated at the atrium. DWTAP and LSCATT coexist around the mid-part of the OAP upstroke.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0123050.g004: Influence of DWTAP and LSCATT on the OAP upstroke.(A-C) Traces of all upstrokes obtained for atrial/endo-/epi-pacing: simultaneous recordings of a subendo-AP (black line), epi-AP (gray line), and an OAP (light gray line) compared with the calculated TAP (dot line) and DWTAP (dashed line) signals. (D-F) Comparison of the OAP and DWTAP (same as in A-C). The difference between these signals provided the LSCATT (gray area); for better visualization, this LSCATT is also shown along the x-axis (dashed area).Note that a positive peak and a negative peak indicate an oncoming and receding wave, respectively, induced by LSCATT only when stimulated at the endo- or epicardium but not when stimulated at the atrium. DWTAP and LSCATT coexist around the mid-part of the OAP upstroke.
Mentions: Fig 4A–4C shows the upstroke shapes in detail for APs obtained for three different types of pacing. When stimulated from the atrium, the DWTAP and OAP upstrokes highly coincided because under such experimental conditions, LSCATT is almost negligible (Fig 4D). However, as shown in Fig 4E and 4F, during endo-/epicardial stimulation, the calculated DWTAP upstrokes were still not equivalent to OAP. This finding indicates that the remaining part (Fig 4E and 4F, gray area or shaded area) of the OAP upstroke could be attributed to LSCATT. The largest difference between the OAP upstroke and DWTAP was obtained during the epi-pacing, apparently because a large lateral-scattering component occurred under such circumstances.

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