AI Article Synopsis
- Atrial conduction velocity (CV) is important in understanding heart conditions like atrial fibrillation, and it can be influenced by the body's autonomic nervous system.
- This study investigated how CV in the right atrium changes with sympathetic stimulation, either through medication (isoproterenol) or direct electrical stimulation of the vertebral vein.
- Results showed that both methods significantly increased CV and reduced CV variability compared to baseline sinus rhythm, indicating that sympathetic stimulation improves heart conduction efficiency.
Article Abstract
Background: Atrial conduction velocity (CV) is influenced by autonomic tone and contributes to the pathophysiology of re-entrant arrhythmias and atrial fibrillation. Cardiac sympathetic nerve activation has been reported via electrical stimulation within the vertebral vein (VV).
Objectives: This study sought to characterize changes in right atrial (RA) CV associated with sympathetic stimulation from pharmacologic (isoproterenol) or direct electrical (VV stimulation) approaches.
Methods: Subjects undergoing catheter ablation for atrial fibrillation had baseline RA electroanatomic maps performed in sinus rhythm (SR). RA mapping was repeated during right VV stimulation (20 Hz; up to 20 mA) and again with both RA pacing and during isoproterenol infusion, each titrated to the heart rate achieved with VV stimulation.
Results: A total of 100 RA maps were analyzed from 25 subjects (mean age: 58 ± 14 years; 56% male), and CV was calculated from 51,534 electroanatomic map points. VV stimulation increased heart rate from baseline in all subjects (22.5 ± 5.5 beats/min). The average CV increased with VV stimulation (82.0 ± 34.5 cm/s) or isoproterenol (83.7 ± 35.0 cm/s) when compared to SR (70.8 ± 32.5 cm/s; P < 0.001). Heterogeneity of CV decreased with VV stimulation or isoproterenol when compared to SR (coefficient of variation: 0.33 ± 0.21 vs 0.35 ± 0.23 vs 0.57 ± 0.29; P < 0.001). There was no difference in CV or CV heterogeneity between SR and RA pacing, suggesting that these changes were independent of heart rate.
Conclusions: Global RA CV is enhanced, and heterogeneity of CV is reduced, with either pharmacologic or direct electrical sympathetic stimulation via the right VV.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jacep.2024.08.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Central Sleep Apnea and Cardiovascular Disease State-of-the-Art.
Sleep
December 2024
Midwest Cardiovascular Institute, Naperville, Illinois, USA.
Central sleep apnea (CSA), a rare polysomnographic finding in the general population, is prevalent in certain cardiovascular conditions including systolic and diastolic left ventricular dysfunction, atrial fibrillation, coronary artery disease, carotid artery stenosis, stroke and use of certain cardiac-related medications. Polysomnographic findings of CSA with adverse cardiovascular impacts include nocturnal hypoxemia and arousals, which can lead to increased sympathetic activity both at night and in the daytime. Among cardiovascular diseases, CSA is most prevalent in patients with left ventricular systolic dysfunction; a large study of more than 900 treated patients has shown a dose dependent relationship between nocturnal desaturation and mortality.
View Article and Find Full Text PDFAstrocyte Loss Augments Body Weight Through Reduction in Adipose Sympathetic Outflows.
Glia
January 2025
Department of Medicine Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York, USA.
Emerging evidence indicates that astrocytes modulate energy metabolism and homeostasis. However, one important but poorly understood element is the necessity of astrocytes in the control of body weight. Here, we apply viral vector-assisted brain-region selective loss of astrocytes to define physiological roles played by astrocytes in the arcuate nucleus of the hypothalamus (ARH) and to elucidate the involved mechanism.
View Article and Find Full Text PDFThe role of the dorsomedial hypothalamus in the cardiogenic sympathetic reflex in the Sprague Dawley rat.
Front Physiol
December 2024
Biomedical Science Department, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.
Myocardial ischemia causes the production and release of metabolites such as bradykinin, which stimulates cardiac spinal sensory afferents, causing chest pain and an increase in sympathetic activity referred to as the cardiogenic sympathetic afferent reflex. While the brain stem nuclei, such as the nucleus tractus solitarius and rostral ventrolateral medulla, are essential in the cardiogenic sympathetic afferent reflex, the role of other supramedullary nuclei in the cardiogenic sympathetic afferent reflex are not clear. The dorsomedial hypothalamic nucleus (DMH) is involved in cardiovascular sympathetic regulation and plays an important role in the sympathetic response to stressful stimuli.
View Article and Find Full Text PDFAltered Protein Kinase A-Dependent Phosphorylation of Cav1.2 in Left Ventricular Myocardium from Haploinsufficient Rat Hearts.
Int J Mol Sci
December 2024
Institute of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, Biochemical and Pharmacological Center (BPC) Marburg, University of Marburg, 35032 Marburg, Germany.
encodes the α1c subunit of the L-type Ca channel, Cav1.2. Ventricular myocytes from haploinsufficient () rats exhibited reduced expression of Cav1.
View Article and Find Full Text PDFEffects of Different Transcranial Direct Current Stimulation Intensities over Dorsolateral Prefrontal Cortex on Brain Electrical Activity and Heart Rate Variability in Healthy and Fibromyalgia Women: A Randomized Crossover Trial.
J Clin Med
December 2024
Grupo de Investigación en Actividad Física Calidad de Vida y Salud (AFYCAV), Facultad de Ciencias del Deporte, Universidad de Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
People with fibromyalgia (FM) exhibit alterations in brain electrical activity and autonomic modulation compared to healthy individuals. : This study aimed to investigate transcranial direct current stimulation (tDCS) effects on brain electrocortical activity and heart rate variability (HRV), specifically targeting the dorsolateral prefrontal cortex in both healthy controls (HC) and FM groups, to identify potential differences in the responses between these groups, and to compare the effectiveness of two distinct tDCS intensities (1 mA and 2 mA) against a sham condition. : Electroencephalography and electrocardiogram signals were recorded pre- and post-tDCS intervention.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!