Detection Algorithm of Phase Singularity Using Phase Variance Analysis for Epicardial Optical Mapping Data

Tomii, Naoki; Yamazaki, Masatoshi; Arafune, Tatsuhiko; Honjo, Haruo; Shibata, Nitaro; Sakuma, Ichiro

doi:10.1109/tbme.2015.2502726

Cited by 23 publications

(24 citation statements)

References 34 publications

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“…Next, in both x and y direction, the phases were derived and a linear combination with the Sobel (we also tested the Nabla) kernels to detect the singularities was applied. This protocol was previously presented (28)(29)(30)(31)(32), but instead of the Hilbert transform we made use of the sawtooth wave for the phases. In 3D, the heart was sliced in 3 orthogonal directions and the protocol was applied on each slice.…”

Section: Phase Mapping Protocolmentioning

confidence: 99%

Directed networks as a novel way to describe and analyze cardiac excitation: Directed Graph mapping

Vandersickel

Nieuwenhuyse

Cleemput

et al. 2019

Preprint

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Networks provide a powerful methodology with applications in a variety of biological, technological and social systems such as analysis of brain data, social networks, internet search engine algorithms, etc. To date, directed networks have not yet been applied to characterize the excitation of the human heart. In clinical practice, cardiac excitation is recorded by multiple discrete electrodes. During (normal) sinus rhythm or during cardiac arrhythmias, successive excitation connects neighboring electrodes, resulting in their own unique directed network. This in theory makes it a perfect fit for directed network analysis. In this study, we applied directed networks to the heart in order to describe and characterize cardiac arrhythmias. Proofof-principle was established using in-silico and clinical data. We demonstrated that tools used in network theory analysis allow to determine the mechanism and location of certain cardiac arrhythmias. We show that the robustness of this approach can potentially exceed the existing state-of-the art methodology used in clinics. Furthermore, implementation of these techniques in daily practice can improve accuracy and speed of cardiac arrhythmia analysis. It may also provide novel insights in arrhythmias that are still incompletely understood. network theory| cardiac arrhythmia Correspondence: nele.vandersickel@ugent.be

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Section: Phase Mapping Protocolmentioning

confidence: 99%

Directed networks as a novel way to describe and analyze cardiac excitation: Directed Graph mapping

Vandersickel

Nieuwenhuyse

Cleemput

et al. 2019

Preprint

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“…Phase analysis has been proposed to analyze SW center during VTs [27]. Moreover, to detect spatiotemporal movement of SW center during VTs, phase variance analysis has been proposed [28]. Taking these two, both the phase map and the phase variance map were calculated from the membrane potential distribution to analyze the SW center movement during VTs.…”

Section: Discussionmentioning

confidence: 99%

Cardiac Spiral Wave Termination by Linear Regional Cooling Toward the Anatomical Boundary of the Heart

et al. 2020

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Purpose We hypothesized that linear regional cooling (LRC) toward the atrio-ventricular groove (AV-G) can move the spiral wave (SW) center to the AV-G effectively and terminate SW. The effectiveness of LRC in ex vivo 2D ventricle rabbit experiments was tested. Methods We developed an experimental system to operate LRC and optical mapping simultaneously. To realize simultaneous cooling and optical mapping, a transparent cooling device was developed. LRC for 60 s toward 2D subepicardial ventricular myocardium of Langendorff-perfused rabbit hearts (n = 4) was conducted during constant pacing and persistent ventricular tachyarrhythmias (VTs). Results Action potential duration at 90% repolarization (APD 90 ) at the cooling area was prolonged by LRC from 187 to 228 ms. 41% of persistent VTs were terminated by LRC (12/29 cases). Cases where the original SW center moved toward the AV-G were observed via optical mapping. However, there were some cases where VT was not terminated by LRC. When the action potential duration (APD) of VT sustained cases were analyzed, LRC prolonged APD, but the APD prolonged area did not move toward the AV-G in most VT sustained cases Conclusion Proper LRC toward the AV-G near the original SW center could move this center toward the AV-G and terminate SW excitation.

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“…In our previous work, we proposed a detection algorithm for the PS using phase variance analysis (25). Briefly, this method allows us to detect PSs by examining various events in the timing of the spiral and identifying the position around which these are focused.…”

Section: Detection Of Pssmentioning

confidence: 99%

“…To test our hypothesis, we performed biphasic point stimulation toward the SW on isolated rabbit heart samples in various stimulation conditions. Consequently, we extracted PS trajectories just after stimulation by using phase variance analysis (25) and analyzed the effect of point stimulation on SWs through the extracted PS trajectories.…”

Section: Action Mechanisms Of Stimulation In An Excitable Gapmentioning

confidence: 99%

“…Biphasic point simulations were applied toward the SW in various conditions, such as timing and relative position. We analyzed optical mapping measurement (5) with phase variance analysis (25), which is an analysis method of the SW that has been suggested in our previous work to quantitatively identify the complex PS trajectories just after the stimulation. The effects of stimulations were analyzed in detail through the extracted PS trajectories.…”

Section: Introductionmentioning

confidence: 99%

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Interaction of phase singularities on the spiral wave tail: reconsideration of capturing the excitable gap

Tomii

Yamazaki

Arafune

et al. 2018

American Journal of Physiology-Heart and Circulatory Physiology

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The action mechanism of stimulation toward spiral waves (SWs) owing to the complex excitation patterns that occur just after point stimulation has not yet been experimentally clarified. This study sought to test our hypothesis that the effect of capturing excitable gap of SWs by stimulation can also be explained as the interaction of original phase singularity (PS) and PSs induced by the stimulation on the wave tail (WT) of the original SW. Phase variance analysis was used to quantitatively analyze the postshock PS trajectories. In a two-dimensional subepicardial layer of Langendorff-perfused rabbit hearts, optical mapping was used to record the excitation pattern during stimulation. After a SW was induced by S1-S2 shock, single biphasic point stimulation S3 was applied. In 70 of the S1-S2-S3 stimulation episodes applied on 6 hearts, the original PS was clearly observed just before the S3 point stimulation in 37 episodes. Pairwise PSs were newly induced by the S3 in 20 episodes. The original PS collided with the newly induced PSs in 16 episodes; otherwise, they did not interact with the original PS. SW shift occurred most efficiently when the S3 shock was applied at the relative refractory period, and PS shifted in the direction of the WT. In conclusion, quantitative tracking of PS clarified that stimulation in desirable conditions induces pairwise PSs on WT and that the collision of PSs causes SW shift along the WT. The results of this study indicate the importance of the interaction of shock-induced excitation with the WT for effective stimulation. NEW & NOTEWORTHY The quantitative analysis of spiral wave dynamics during stimulation clarified the action mechanism of capturing the excitable gap, i.e., the induction of pairwise phase singularities on the wave tail and spiral wave shift along the wave tail as a result of these interactions. The importance of the wave tail for effective stimulation was revealed.

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Detection Algorithm of Phase Singularity Using Phase Variance Analysis for Epicardial Optical Mapping Data

Abstract: The proposed method will reveal the spiral wave dynamics in optical mapping images better than existing approaches. The objective analysis method of a spiral wave is important for understanding the mechanisms and dynamics of serious heart arrhythmias.

Cited by 23 publications

References 34 publications

Directed networks as a novel way to describe and analyze cardiac excitation: Directed Graph mapping

Directed networks as a novel way to describe and analyze cardiac excitation: Directed Graph mapping

Cardiac Spiral Wave Termination by Linear Regional Cooling Toward the Anatomical Boundary of the Heart

Interaction of phase singularities on the spiral wave tail: reconsideration of capturing the excitable gap

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