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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

Mean data for the components composing the OAP upstroke.Bars represent the durations (means ± SEMs) for all components that contribute to the OAP upstroke: a transmural AP recorded with a microelectrode versus a full OAP (the sum of the depth-weighted TAP and the lateral-scattering component) obtained with the di-4-ANBDQBS dye, when stimulated in the atrium/endocardium/epicardium. The dark gray bar indicates the TAP, and the gray and light gray bars indicate the DWTAP and LSCATT components, respectively. The durations of the upstroke for TAP, DWTAP, and OAP were calculated using the time points that corresponded to 10 and 90% of the amplitude. LSCATT was calculated as the difference between OAP and DWTAP. Note that LSCATT was significantly different (P <0.05, n = 8 for each) for the various types of pacing.
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pone.0123050.g006: Mean data for the components composing the OAP upstroke.Bars represent the durations (means ± SEMs) for all components that contribute to the OAP upstroke: a transmural AP recorded with a microelectrode versus a full OAP (the sum of the depth-weighted TAP and the lateral-scattering component) obtained with the di-4-ANBDQBS dye, when stimulated in the atrium/endocardium/epicardium. The dark gray bar indicates the TAP, and the gray and light gray bars indicate the DWTAP and LSCATT components, respectively. The durations of the upstroke for TAP, DWTAP, and OAP were calculated using the time points that corresponded to 10 and 90% of the amplitude. LSCATT was calculated as the difference between OAP and DWTAP. Note that LSCATT was significantly different (P <0.05, n = 8 for each) for the various types of pacing.

Mentions: Fig 6 shows a quantitative evaluation of OAP upstroke components. The mean values for TAP, DWTAP, and LSCATT were 9.79 ± 0.84 ms, 10.18 ± 0.62 ms, and 0.0 ± 0.56 ms, respectively, for atrial pacing, 9.83 ± 1.32 ms, 9.37 ± 1.12 ms, and 3.01 ± 1.30 ms, respectively, for endocardial pacing, and 6.19 ± 1.16 ms, 6.09 ± 0.79 ms, and 8.16 ± 0.98 ms, respectively, for epicardial pacing (n = 8 for each).


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)

Mean data for the components composing the OAP upstroke.Bars represent the durations (means ± SEMs) for all components that contribute to the OAP upstroke: a transmural AP recorded with a microelectrode versus a full OAP (the sum of the depth-weighted TAP and the lateral-scattering component) obtained with the di-4-ANBDQBS dye, when stimulated in the atrium/endocardium/epicardium. The dark gray bar indicates the TAP, and the gray and light gray bars indicate the DWTAP and LSCATT components, respectively. The durations of the upstroke for TAP, DWTAP, and OAP were calculated using the time points that corresponded to 10 and 90% of the amplitude. LSCATT was calculated as the difference between OAP and DWTAP. Note that LSCATT was significantly different (P <0.05, n = 8 for each) for the various types of pacing.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0123050.g006: Mean data for the components composing the OAP upstroke.Bars represent the durations (means ± SEMs) for all components that contribute to the OAP upstroke: a transmural AP recorded with a microelectrode versus a full OAP (the sum of the depth-weighted TAP and the lateral-scattering component) obtained with the di-4-ANBDQBS dye, when stimulated in the atrium/endocardium/epicardium. The dark gray bar indicates the TAP, and the gray and light gray bars indicate the DWTAP and LSCATT components, respectively. The durations of the upstroke for TAP, DWTAP, and OAP were calculated using the time points that corresponded to 10 and 90% of the amplitude. LSCATT was calculated as the difference between OAP and DWTAP. Note that LSCATT was significantly different (P <0.05, n = 8 for each) for the various types of pacing.
Mentions: Fig 6 shows a quantitative evaluation of OAP upstroke components. The mean values for TAP, DWTAP, and LSCATT were 9.79 ± 0.84 ms, 10.18 ± 0.62 ms, and 0.0 ± 0.56 ms, respectively, for atrial pacing, 9.83 ± 1.32 ms, 9.37 ± 1.12 ms, and 3.01 ± 1.30 ms, respectively, for endocardial pacing, and 6.19 ± 1.16 ms, 6.09 ± 0.79 ms, and 8.16 ± 0.98 ms, respectively, for epicardial pacing (n = 8 for each).

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