Motahareh Moghtadaei

• PhD
• Resercher at University of Calgary

Aging is a major risk factor for sinoatrial node (SAN) dysfunction, which can impair heart rate (HR) control and heart rate variability (HRV). HR and HRV are determined by intrinsic SAN function and its regulation by the autonomic nervous system (ANS). The purpose of this study was to use multi-scale multi-fractal detrended fluctuation analysis (MS...

Nonlinear analyses of heart rate variability (HRV) can be used to quantify the unpredictability, fractal properties and complexity of heart rate. Fractality and its analysis provides valuable information about cardiovascular health. Multi-Scale Multi-Fractal Detrended Fluctuation Analysis (MSMFDFA) is a complexity-based algorithm that can be used t...

Heart rate is controlled by the sinoatrial node (SAN). SAN dysfunction is highly prevalent in aging; however, not all individuals age at the same rate. Rather, health status during aging is affected by frailty. Natriuretic peptides regulate SAN function in part by activating natriuretic peptide receptor C (NPR-C). The impacts of NPR-C on HR and SAN...

Background Atrial fibrillation is prevalent in aging populations; however, not all individuals age at the same rate. Rather, health status during aging can vary from fit to frail. Frailty can be quantified using a frailty index (FI). Natriuretic peptides modulate atrial function in part by activating NP (natriuretic peptide) receptor C (NPR-C). The...

Background: Heart rate variability (HRV) is determined by intrinsic sinoatrial node (SAN) activity and the autonomic nervous system (ANS). HRV is reduced in aging; however, aging is heterogeneous. Frailty, which can be measured using a frailty index (FI), can quantify health status in aging separately from chronological age. Objective: To invest...

Background: Atrial fibrillation (AF) is highly prevalent in diabetes mellitus (DM), yet the basis for this is poorly understood. Type 2 DM may be associated with unique patterns of atrial electrical and structural remodeling; however, this has not been investigated in detail. Objective: To investigate AF susceptibility and atrial electrical and st...

Significance Atrial fibrillation (AF) is prevalent in diabetic patients, yet the basis for AF in diabetes is poorly understood. We have used type 1 diabetic Akita mice to study the effects of insulin on atrial electrophysiology in diabetes. We demonstrate that Akita mice are highly susceptible to AF due to impaired electrical conduction and that in...

Background Hypertensive heart disease is associated with sinoatrial node (SAN) dysfunction and reductions in heart rate variability (HRV). Alterations in HRV could occur in association with changes in ANS activity, SAN function and responsiveness to ANS agonists, or both. These relationships are unclear. Objective To investigate the roles of ANS s...

Vagal control of the sinoatrial node (SAN) is a major mechanism that regulates beat-to-beat heart rate variability (HRV) at rest. Classically, reduced HRV in the setting of hypertensive heart disease and heart failure has been attributed to chronically elevated sympathetic and reduced vagal regulation of heart rate. However, both of these condition...

Atrial fibrillation (AF), which is the most commonly diagnosed arrhythmia, is characterized by rapid, irregular electrical activity in the atria. AF is highly prevalent in diabetes mellitus (DM), resulting in increased morbidity and mortality in diabetic patients affected by this arrhythmia. Type 2 DM (T2DM), which is the predominant form of DM, is...

Cardiac looping is an essential and highly conserved morphogenetic process that places the different regions of the developing vertebrate heart tube into proximity of their final topographical positions. High-resolution 4D live imaging of mosaically-labelled cardiomyocytes reveals distinct cardiomyocyte behaviors that contribute to the deformation...

Background: Atrial fibrillation (AF) commonly occurs in hypertension and in association with elevated Ang II (angiotensin II) levels. The specific mechanisms underlying Ang II-mediated AF are unclear, and interventions to prevent the effects of Ang II are lacking. NPs (natriuretic peptides), which elicit their effects through specific NP receptors...

Sinoatrial node (SAN) disease mechanisms are poorly understood, and therapeutic options are limited. Natriuretic peptide(s) (NP) are cardioprotective hormones whose effects can be mediated partly by the NP receptor C (NPR-C). We investigated the role of NPR-C in angiotensin II (Ang II)-mediated SAN disease in mice. Ang II caused SAN disease due to...

Atrial fibrillation (AF) is prevalent in hypertension and elevated angiotensin II (Ang II); however, the mechanisms by which Ang II leads to AF are poorly understood. Here, we investigated the basis for this in mice treated with Ang II or saline for 3 weeks. Ang II treatment increased susceptibility to AF compared to saline controls in association...

Natriuretic peptides (NPs) play essential roles in the regulation of cardiovascular function. NP effects are mediated by receptors known as NPR-A, NPR-B or NPR-C. NPs have potent effects on regulation of heart rate (HR) by the autonomic nervous system (ANS), but the role of NPR-C in these effects has not been investigated. Accordingly, we have used...

Atrial fibrillation (AF) is prevalent in aging populations; however not all individuals age at the same rate. Instead, individuals of the same chronological age can vary in health status from fit to frail. Our objective was to determine the impacts of age and frailty on atrial function and arrhythmogenesis in mice using a frailty index (FI). Aged m...

In this note, hidden attractors in chaotic maps are investigated. Although there are many new researches on hidden attractors in chaotic flows, no investigation has been done on hidden attractors in maps based on our knowledge. In addition, a new interesting chaotic map with a bifurcation diagram starting from any desired period and then continuing...

Key points: Sinoatrial node (SAN) function declines with age; however, not all individuals age at the same rate and health status can vary from fit to frail. Frailty was quantified in young and aged mice using a non-invasive frailty index so that the impacts of age and frailty on heart rate and SAN function could be assessed. SAN function was impa...

-Atrial natriuretic peptide (ANP) is a hormone with numerous beneficial cardiovascular effects. Recently, a mutation in the atrial natriuretic peptide (ANP) gene, which results in the generation of a mutant form of ANP (mANP), was identified and shown to cause atrial fibrillation (AF) in people. The mechanism(s) through which mANP causes AF are unk...

Cardiovascular autonomic neuropathy (CAN) is a serious complication of diabetes mellitus that impairs autonomic regulation of heart rate (HR). This has been attributed to damage to the nerves that modulate spontaneous pacemaker activity in the sinoatrial node (SAN). Our objective was to test the hypothesis that impaired parasympathetic regulation o...

Key points Natriuretic peptides (NPs) elicit their effects via multiple NP receptors (including NPR‐A, NPR‐B and NPR‐C, with NPR‐C being relatively poorly understood). We have studied the effects of NPR‐C ablation on cardiac structure, function and arrhythmogenesis using NPR‐C knockout (NPR‐C −/− ) mice. NPR‐C −/− mice are characterized by sinoatri...

A one-dimensional map is proposed for modeling some of the neuronal activities, including different spiking and bursting behaviors. The model is obtained by applying some modifications on the well-known Logistic map and is named the Modified and Confined Logistic (MCL) model. Map-based neuron models are known as phenomenological models and recently...

Clinicians and oncologists believe that tumor growth has unpredictable dynamics. For this reason they encounter many difficulties in the treatment of cancer. Mathematical modeling is a great tool to improve our better understanding of the complicated biological system of tumor growth. Also, it can help to identify states of the disease and as a res...

Identification of squamous dysplasia and esophageal squamous cell carcinoma (ESCC) is of great importance in prevention of cancer incidence. Computer aided algorithms can be very useful for identification of people with higher risks of squamous dysplasia, and ESCC. Such method can limit the clinical screenings to people with higher risks. Different...

This study compares the dynamic behaviors of the Lorenz system with complex variables to that of the standard Lorenz system involving real variables. Different methodologies, including the Lyapunov Exponents spectrum, the bifurcation diagram, the first return map to the Poincaré section and topological entropy, were used to investigate and compare...