A5068328556- Cardiac electrophysiology and arrhythmias
- Heart Rate Variability and Autonomic Control
- Ion channel regulation and function
- Circadian rhythm and melatonin
- Neuroscience and Neural Engineering
- Genetics, Aging, and Longevity in Model Organisms
- Cardiac Arrhythmias and Treatments
- Non-Invasive Vital Sign Monitoring
- ECG Monitoring and Analysis
- Mitochondrial Function and Pathology
- Electrochemical Analysis and Applications
- Blood Pressure and Hypertension Studies
- Receptor Mechanisms and Signaling
- Adipose Tissue and Metabolism
- Neuroscience of respiration and sleep
- Cardiomyopathy and Myosin Studies
- Biochemical effects in animals
- Stress Responses and Cortisol
- Photoreceptor and optogenetics research
- Neuroscience and Neuropharmacology Research
- Heart Failure Treatment and Management
- Cardiovascular Function and Risk Factors
- Birth, Development, and Health
- Thermoregulation and physiological responses
- Pain Mechanisms and Treatments
University of Kentucky
2013-2025
Asbury University
2002-2020
Heidenhain (United Kingdom)
2012
R231H Causes a High Penetrance for Familial AF Background Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its incidence expected to grow. A genetic predisposition has long been recognized, but manifestation in these patients likely involves combination of rare variants. Identifying variants that associate with high penetrance would represent significant breakthrough understanding mechanisms disease. Method Results Candidate gene sequencing 5 unrelated families familial...
We have described a 0.4-Hz rhythm in renal sympathetic nerve activity (SNA) that is tightly coupled to oscillations blood pressure the unanesthetized rat. In previous work, relationship between SNA and fluctuations mean arterial (MAP) was by set of two first-order differential equations. now modified our earlier model test feasibility can be explained baroreflex without requiring neural oscillator. this model, linear feedback term replaces drive cardiovascular system. The time delay loop...
Rhythmic feeding behavior is critical for regulating phase and amplitude in the ≈24-h variation of heart rate (RR intervals), ventricular repolarization (QT core body temperature mice. We hypothesized changes cardiac electrophysiology associated with were secondary to temperature. Telemetry was used record electrocardiograms mice during ad libitum-fed conditions after inverting normal by restricting food access light cycle. Light cycle-restricted modified 24-h rhythms RR QT intervals,...
In this study we tested the hypothesis that ventricular homeostasis of L-type Ca 2+ current ( I Ca,L ) minimally involves regulation main pore-forming α-subunit (Ca V 1.2) and auxiliary proteins serve as positive or negative regulators . We treated animals for 24 h with verapamil (Ver, 3.6 mg·kg −1 ·day ), isoproterenol (Iso, 30 Iso + Ver via osmotic minipumps. To test alterations channel complex components performed real-time PCR Western blot analysis on ventricle. addition, cardiac...
Long QT syndrome type 3 (LQT3) is caused by mutations in the SCN5A-encoded Nav1.5 channel. LQT3 patients exhibit time of day-associated abnormal increases their heart rate-corrected (QTc) intervals and risk for life-threatening episodes. This study determines effects uncoupling environmental cues that entrain circadian rhythms (time light feeding) on rate ventricular repolarization wild-type (WT) or transgenic mice (Scn5a(+/ΔKPQ)). We used an established phase-restricted feeding paradigm...
Type 1 long QT syndrome (LQT1) is caused by loss-of-function mutations in the KCNQ1 gene, which encodes K+ channel (Kv7.1) that underlies slowly activating delayed rectifier current heart. Intragenic risk stratification suggests LQT1 disrupt conserved amino acid residues pore are an independent factor for LQT1-related cardiac events. The purpose of this study to determine possible molecular mechanisms underlie loss function these high-risk mutations. Extensive genotype–phenotype analyses...
Circadian rhythms are generated by cell autonomous circadian clocks that perform a ubiquitous cellular time-keeping function and type-specific functions important for normal physiology. Studies show inducing the deletion of core clock transcription factor Bmal1 in adult mouse cardiomyocytes disrupts cardiac function, ion channel expression, slows heart rate, prolongs QT-interval at slow rates. This study determined how impacted vivo electrophysiological phenotype knock-in model...
The object of this study is to quantify the very low frequency (i.e., <0.1 Hz) interactions between renal sympathetic nerve activity (SNA) and arterial blood pressure (ABP). Six rats were instrumented for chronic recordings SNA ABP. Data collected 24 h after surgery at 10 kHz 2–5 subsequently compressed a 1-kHz signal. power spectra ordinary coherence calculated from data epochs up 1 in length. both variables fitted constant times f −β . peak magnitude squared near 0.4 Hz was 0.82 ± 0.08,...
This experiment quantified the initial disruption and subsequent adaptation of blood pressure (BP)-heart rate (HR) relationship after spinal cord transection (SCT). BP HR were recorded for 4 h via an implanted catheter in neurally intact, unanesthetized rats. The animals then anesthetized, their cords severed at T 1 –T 2 ( n = 5) or 5 6) sham lesioned 4). was daily over ensuing 6 days. intact rat showed a positive cross correlation, with leading peak by 1.8 ± 0.8 (SD) s. correlation rats n=...
Cardiac electrophysiological studies demonstrate that restricting the feeding of mice to light cycle (time restricted or TRF) causes a pronounced change in heart rate and ventricular repolarization as measured by RR- QT-interval, respectively. TRF slows shifts peak (acrophase) day/night rhythms QT-intervals from dark cycle. This study tested hypothesis these changes cardiac electrophysiology are driven cardiomyocyte circadian clock mechanism. We determined impact had on control mechanism...
The goal of this analysis was to quantify the relationship between renal sympathetic nerve activity (SNA) and mean arterial blood pressure (MAP). We previously recorded SNA MAP in conscious rats during a stressful behavioral stimulus nonstressful stimulus. then formulated set two linear, first-order differential equations that uses our recordings after time delay (the input) predict fluctuations output). Our model has four parameters: 1) cardiovascular constant T characterizes frequency...
We recorded via telemetry the arterial blood pressure (BP) and heart rate (HR) response to classical conditioning following spontaneous onset of autoimmune diabetes in BBDP/Wor rats vs. age-matched, diabetes-resistant control (BBDR/Wor) rats. Our purpose was evaluate autonomic regulatory responses an acute stress a diabetic state up 12 months duration. The 15-s pulsed tone (CS+) followed by 0.5-s tail shock. initial, transient increase BP (i.e., "first component," or C(1)), known be derived...