We examined the relationship between postpacing T wave changes and monophasic action potentials recorded from the ventricle in dogs. MAPs were recorded from the right and left ventricle before and after cessation of pacing. The duration of the MAP was calculated as the time in milliseconds from the upstroke to 90% repolarization (MAPD90). T waves in limb leads were flat or had a biphasic pattern, eventually becoming negative after pacing. The Q-T interval of the escape beat after pacing was prolonged compared with the control. After right ventricular pacing, the average duration of MAPD90 in the right ventricle, but not in the left ventricle, was prolonged. (right MAPD: control 275 +/- 10 ms; after pacing: 311 +/- 17 ms, p < 0.05; left MAPD: control: 266 +/- 23 ms, after pacing: 284 +/- 26 ms, NS). After left ventricular pacing, the average duration of MAPD90 in the left ventricle, but not in the right ventricle, was prolonged (right MAPD: control: 247 +/- 75 ms, after pacing: 287 +/- 39 ms, NS; left MAPD: control: 257 +/- 23 ms, after pacing: 303 +/- 25 ms, p < 0.05). Furthermore, the average duration of MAPD90 at the pacing site became progressively prolonged over time. These results suggest that myocardial cells retain the memory of abnormal repolarization associated with pacing.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1159/000175977 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Subcomponent analysis of the directional sensitivity of dynamic cerebral autoregulation.
Am J Physiol Heart Circ Physiol
January 2025
Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM), Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.
Article Synopsis
- The study investigates the unknown origin of directional sensitivity (DS) in dynamic cerebral autoregulation (dCA) using measurements from 140 healthy participants, focusing on middle cerebral artery velocity (MCAv) and arterial blood pressure (ABP).
- Results show that MCAv and resistance-area product (RAP) exhibit significant directional sensitivity in response to changes in mean arterial pressure (MAP), while critical closing pressure (CrCP) does not.
- The findings suggest that the directional sensitivity in cerebral blood flow is likely myogenic (related to muscle response) and is primarily mediated by RAP, indicating minimal influence from metabolic factors or sympathetic nervous system control.
Efficacy of PZT Sensors Network Different Configurations in Damage Detection of Fiber-Reinforced Concrete Prisms under Repeated Loading.
Sensors (Basel)
August 2024
Architectural Engineering Department, School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece.
Real-time structural health monitoring (SHM) and accurate diagnosis of imminent damage are critical to ensure the structural safety of conventional reinforced concrete (RC) and fiber-reinforced concrete (FRC) structures. Implementations of a piezoelectric lead zirconate titanate (PZT) sensor network in the critical areas of structural members can identify the damage level. This study uses a recently developed PZT-enabled Electro-Mechanical Impedance (EMI)-based, real-time, wireless, and portable SHM and damage detection system in prismatic specimens subjected to flexural repeated loading plain concrete (PC) and FRC.
View Article and Find Full Text PDFCharacterizing Mechanical Changes in the Biceps Brachii Muscle in Mild Facioscapulohumeral Muscular Dystrophy Using Shear Wave Elastography.
Diagnostics (Basel)
September 2024
Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany.
There is no general consensus on evaluating disease progression in facioscapulohumeral muscular dystrophy (FSHD). Recently, shear wave elastography (SWE) has been proposed as a noninvasive diagnostic tool to assess muscle stiffness in vivo. Therefore, this study aimed to characterize biceps brachii (BB) muscle mechanics in mild-FSHD patients using SWE.
View Article and Find Full Text PDFRapid reduction of air pollution and short-term exposure risks in China.
J Environ Sci (China)
March 2025
College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
Article Synopsis
- China’s air quality has improved a lot in recent years because they are controlling pollution better.
- Researchers looked at air pollution data from 2015 to 2022 and found that most air pollutants, except ozone, are decreasing every year.
- While the risk from air pollution is lower now, it varies by region, with some areas still having higher risks, mainly from tiny particles in the air.
Clinical characteristics and antimicrobial susceptibility profiles of Mycobacterium abscessus and Mycobacterium massiliense pulmonary infection.
J Glob Antimicrob Resist
September 2024
State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. Electronic address:
Objectives: Mycobacterium abscessus complex (MABC) is the most common rapidly growing Mycobacterium species in structural pulmonary diseases and can be life-threatening. This study aimed to assess the clinical characteristics and drug-susceptibility statuses of different M. abscessus (MAB) subspecies in the Zhejiang Province.
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!