Wavelet analysis of cardiac optical mapping data

Xiong, Feng; Qi, Xiaoyan; Nattel, Stanley; Comtois, Philippe

doi:10.1016/j.compbiomed.2015.06.022

Cited by 20 publications

(6 citation statements)

References 62 publications

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“…Images were acquired at 500 frames per second for consistency and the optimal signal-to-noise ratio. The conduction velocity (CV) was analysed using a MATLAB ® custom-written algorithm, as previously described [ 35 , 36 ].…”

Section: Methodsmentioning

confidence: 99%

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling

Liu

Shu

et al. 2022

Cardiovasc Diabetol

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Background Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF. Methods Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca2+) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca2+ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM. Results High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca2+ handling proteins, increased the threshold for Ca2+ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca2+ events, promoted cellular Ca2+ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy. Conclusion DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca2+ handling.

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Section: Methodsmentioning

confidence: 99%

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling

Liu

Shu

et al. 2022

Cardiovasc Diabetol

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“…Optical mapping in a rat AF model was performed as previously described (S12) (19,24,25). The heart was excised and perfused in Langendorff mode with Krebs solution at 30 ml/min and 37°C.…”

Section: Rat Afmentioning

confidence: 99%

Renewal theory provides a universal quantitative framework to characterise the continuous regeneration of rotational events in cardiac fibrillation

Dharmaprani

Schopp

Kuklik³

et al. 2019

Preprint

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Background: Cardiac fibrillation is thought to be maintained by rotational activity, with pivoting regions called phase singularities (PSs). Despite a century of research, no clear quantitative framework exists to model the fundamental processes responsible for the continuous formation and destruction of rotors in fibrillation. Objective:We conducted a multi-modality, multi-species study of AF/VF under the hypothesis that PS formation/destruction in fibrillation can be modelled as self-regenerating renewal processes, producing exponential distributions of inter-event times governed by constant rateparameters defined by the prevailing properties of the system.Methods: PS formation/destruction was studied and cross-validated in 5 models, using basket recordings and optical mapping from: i) human persistent AF (n = 20), ii) tachypaced sheep AF (n = 5), iii) rat AF (n = 4), iv) rat VF (n = 11) and v) computer simulated AF (SIM). Hilbert phase maps were constructed. PS lifetime data were fitted by exponential probability distribution functions (PDFs) computed using maximum entropy theory, and the rate parameter ( ) determined. A systematic review was conducted to cross-validate with source data from literature. Results:PS destruction/formation distributions showed good fits to an exponential in all systems (R 2 ≥ 0.90). In humans, = 4.6%/ms (95%CI,4.3,4.9)), sheep 4.4%/ms (95%CI,4.1,4.7)), rat AF 38%/ms (95%CI,22,55), rat VF 46%/ms (95%CI,31.2,60.2) and SIM 5.4%/ms (95%CI,4.1,6.7). All PS distributions identified through systematic review were exponential with comparable to experimental data. Conclusion:These results provide a universal quantitative framework to explain rotor formation and destruction in AF/VF, and a platform for therapeutic advances in cardiac fibrillation.

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“…In this work, we used four leveled WPD to generate 30 sub-bands. Moreover, a symlet 4 wavelet filter is chosen to decompose signals for this work [32]. Two feature extraction functions are used in the feature extraction step: (i) favipiravir pattern and (ii) statistical feature extractor.…”

Section: Methodsmentioning

confidence: 99%

Novel favipiravir pattern-based learning model for automated detection of specific language impairment disorder using vowels

Barua

Aydemir

Doğan

et al. 2022

Neural Comput & Applic

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Specific language impairment (SLI) is one of the most common diseases in children, and early diagnosis can help to obtain better timely therapy economically. It is difficult and time-consuming for clinicians to accurately detect SLI through standard clinical assessments. Hence, machine learning algorithms have been developed to assist in the accurate diagnosis of SLI. This work aims to investigate the graph of the favipiravir molecule-based feature extraction function and propose an accurate SLI detection model using vowels. We proposed a novel handcrafted machine learning framework. This architecture comprises the favipiravir molecular structure pattern, statistical feature extractor, wavelet packet decomposition (WPD), iterative neighborhood component analysis (INCA), and support vector machine (SVM) classifier. Two feature extraction models, statistical and textural, are employed in the handcrafted feature generation methodology. A new nature-inspired graph-based feature extractor that uses the chemical depiction of the favipiravir (favipiravir became popular with the COVID-19 pandemic) is employed for feature extraction. Finally, the proposed favipiravir pattern, statistical feature extractor, and wavelet packet decomposition are used to create a feature vector. Moreover, a statistical feature extractor is used in this work. The WPD generates multilevel features, and the most meaningful features are selected using the NCA feature selector. Finally, these chosen features are fed to SVM classifier for automated classification. Two validation methods, (i) leave one subject out (LOSO) and (ii) tenfold cross-validations (CV), are used to obtain robust classification results. Our proposed favipiravir pattern-based model developed using a vowel dataset can detect SLI children with an accuracy of 99.87% and 98.86% using tenfold and LOSO CV strategies, respectively. These results demonstrated the high vowel classification ability of the proposed favipiravir pattern-based model.

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Wavelet analysis of cardiac optical mapping data

Cited by 20 publications

References 62 publications

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling

Renewal theory provides a universal quantitative framework to characterise the continuous regeneration of rotational events in cardiac fibrillation

Novel favipiravir pattern-based learning model for automated detection of specific language impairment disorder using vowels

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