Background: The relationship between atrial electrogram (EGM) characteristics in atrial fibrillation (AF) and those in sinus rhythm (SR) are generally unknown. The activation rate and direction may affect EGM characteristics. We examined characteristics of left atrial (LA) EGMs obtained during pacing from different sites.
Methods: The study included 10 patients undergoing pulmonary vein isolation for AF. Atrial EGMs were recorded from a 64-pole basket catheter placed in the LA, and bipolar EGM amplitudes from the distal electrode pair (1-2) and proximal electrode pair (6-7) from 8 splines were averaged. The high right atrium (HRA), proximal coronary sinus (CSp), and distal coronary sinus (CSd) were paced at 600 ms and 300 ms.
Results: When the LA voltage at SR was ≥1.5 mV, bipolar voltages of the HRA were greater than those of the CSp, which were greater than those of the CSd, regardless of the pacing cycle length. The shorter pacing cycle length resulted in a reduction of the LA EGM voltage at sites of SR voltage ≥1.5 mV, but no significant difference was seen at sites where the SR EGM amplitude was between >0.5 and <1.5 mV. No significant differences were seen in intra-basket conduction times between pacing cycle lengths of 600 ms and 300 ms at any pacing site.
Conclusion: The rate and direction-dependent reduction of the amplitude of atrial EGMs may explain, in part, the voltage discordance during SR and AF.
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http://dx.doi.org/10.1016/j.joa.2017.01.001 | DOI Listing |
Alzheimers Dement
December 2024
Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, U.S.A., Philadelphia, PA, USA.
Background: The vicious cycle between depression and dementia increases the risk of Alzheimer's Disease (AD) pathogenesis and pathology. This study investigates therapeutic effectiveness versus side effects and the underlying mechanisms of intranasal dantrolene nanoparticles (IDNs) to treat depression behavior and memory loss in 5XFAD mice.
Method: 5XFAD and wild-type B6SJLF1/J mice were treated with IDNs (IDN, 5 mg/kg) in Ryanodex formulation for a duration of 12 weeks.
J Ultrasound Med
January 2025
Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, Colorado, USA.
Objectives: The size, shape, and contractility of the heart's atrial chambers have not been evaluated in fetuses with growth restriction (FGR) or who are small-for-gestational-age (SGA) as defined by the Delphi consensus protocol. This study aimed to examine the atrial chambers using speckle tracking analysis to identify any changes that may be specific for either growth disturbance.
Methods: Sixty-three fetuses were evaluated with an estimated fetal weight <10th percentile who were classified as FGR or SGA based on the Delphi consensus protocol.
JTCVS Open
December 2024
Division of Pediatric Cardiac Surgery, Department of Cardiothoracic Surgery, Stanford University, Palo Alto, Calif.
Objective: The study objective was to investigate the effect of free-edge length on valve performance in bicuspidization repair of congenitally diseased aortic valves.
Methods: In addition to a constructed unicuspid aortic valve disease model, 3 representative groups-free-edge length to aortic diameter ratio 1.2, 1.
Radiat Oncol
January 2025
Department of Radiation Oncology, Xijing Hospital, Air Force Medical University, Xi'an, 710032, Shaanxi, China.
Purpose: Based on the demonstration of a circadian rhythm in the human oral mucosa cell cycle, with most cells in the G2/M phase in the afternoon and at night, the present study evaluated the severity of acute radiation esophagitis and treatment outcomes in esophageal squamous cell carcinoma patients receiving radiotherapy (RT) in the daytime versus in the evening.
Methods: From the 488 eligible patients of esophageal squamous cell carcinoma receiving concurrent chemoradiotherapy (CCRT), 369 patients received RT in the daytime (before 19:00) and 119 patients received RT in the evening (after 19:00). The grades of radiation esophagitis (Common Terminology Criteria for Adverse Events version 5.
Zhongguo Zhen Jiu
January 2025
College of TCM, Chongqing Medical University, Chongqing Key Laboratory of TCM for Prevention and Treatment of Metabolic Diseases, Chongqing 410007, China.
Objective: To assess the impacts of electroacupuncture (EA) on the gait, oxidative stress, inflammatory reaction, and protein degradation in the rats of denervated skeletal muscle atrophy, and explore the potential mechanism of EA for alleviating denervated skeletal muscle atrophy.
Methods: Forty male SD rats, 8 weeks old, were randomly assigned to a sham-surgery group, a model group, an EA group, and a p38 MAPK inhibitor group, with 10 rats in each group. The right sciatic nerve was transected to establish a rat model of denervated skeletal muscle atrophy in the model group, the EA group and the p38 MAPK inhibitor group.
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