Electrocardiographic repolarization abnormalities characterized by T-wave morphology parameters such as the principal component analysis ratio and the relative and the absolute T-wave residuum (TWR(rel) and TWR(abs)) are predictive of cardiovascular and/or all-cause mortality. However, when using a "10-second median beat" for analysis, the reported mean values for TWR(rel) vary widely and parameter reproducibility is somewhat suspect. In repeated electrocardiographic recordings conducted 1 month and 1 year apart on 15 and 27 healthy individuals, respectively, we studied the said T-wave morphology parameters in single complexes and in reduced noise signal averages containing 10 and 200 complexes. Considering all subjects, the mean (+/-SD) TWR(rel) was highest in a single complex (0.0345% +/- 0.0183%), intermediate in the 10-beat signal-averaged complexes (0.0125% +/- 0.0051%), and lowest in the 200-beat signal-averaged complexes (0.0078% +/- 0.0036%) (P < .0001), with the same trend also observed in the TWR(abs) but not in the principal component analysis ratio. Reproducibility as quantified by within-subject variance and reliability as quantified by the intraclass (intrasubject) correlation coefficient also improved as the number of T-wave complexes analyzed increased. We conclude that signal averages consisting of more than 10 complexes (or more than 10 seconds worth of complexes) are required to produce reproducible and reliable values for TWR(rel) and TWR(abs).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jelectrocard.2005.11.004 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Digital Electrocardiographic Complex for Risk Stratification of Paroxysmal Atrial Fibrillation.
Sovrem Tekhnologii Med
December 2024
MD, PhD, Leading Researcher, Laboratory of Medical Information Technologies; Republican Scientific and Practical Centre "Cardiology", Ministry of Health of the Republic of Belarus, 110 R. Luxembourg St., Minsk, 220036, Belarus.
Unlabelled: was to develop and clinically test a hardware and software system capable of identifying the predictors of the hidden forms of atrial fibrillation (AF) using 12-lead ECG data in sinus rhythm.
Materials And Methods: There was developed the hardware and software system "Intecard 8.1" to assess a set of markers for atrial electrical instability by 3-5-minute ECG recordings in sinus rhythm.
Exploring the relationship between ventricular fibrillation recurrence after defibrillation in myocardial infarction and the effectiveness of renal sympathetic denervation therapy.
BMC Cardiovasc Disord
October 2024
Department of Cardiology, Shanghai Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Objective: This study aimed to explore the association between electrophysiological markers of early recurrence after defibrillation in post-myocardial infarction ventricular fibrillation and the therapeutic effects of sympathetic renal denervation, as well as to investigate the potential underlying mechanisms.
Methods: Experimental research was conducted using an animal model. Myocardial infarction was induced, followed by defibrillation treatment for ventricular fibrillation cases, and the electrophysiological markers of early recurrence were recorded.
Torsades de Pointes electrical storm in children with KCNH2 mutations.
BMC Med Genomics
October 2024
Department of Cardiology, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200062, China.
Article Synopsis
- Congenital long QT syndrome (LQTS) is a genetic heart condition that can cause serious arrhythmias, particularly in children, and can often be mistaken for epilepsy.
- This study highlights two children misdiagnosed with epilepsy who suffered life-threatening cardiac events linked to specific mutations in the KCNH2 gene, found through whole exome sequencing.
- The findings emphasize the importance of evaluating cardiovascular health in patients with epilepsy, especially those with unusual symptoms, and suggest treatment options like Nadolol, cardiac sympathetic denervation, or an implantable cardioverter-defibrillator (ICD) for high-risk LQT2 patients.
Impact of Vernix Caseosa Distribution on Non-Invasive Fetal ECG Morphology: A Computational Study.
IEEE Trans Biomed Eng
October 2024
Article Synopsis
- This study examines how the distribution of vernix caseosa, a fatty substance surrounding the fetus, affects the accuracy of non-invasive fetal ECG monitoring during pregnancy, which is crucial for early detection of fetal health issues.
- A multi-compartment model simulating both fetal and maternal elements was used to analyze fetal cardiac signals under varying conditions of vernix caseosa, revealing its influence primarily in signal strength and ECG morphology.
- Findings indicate that while the presence of vernix caseosa typically does not significantly disrupt ECG readings, it can notably affect the interpretation of the T/QRS ratio, emphasizing the need for careful analysis in clinical settings.
Associations between epilepsy, respiratory impairment, and minor ECG abnormalities in children.
Seizure
November 2024
Division of Pediatric Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA. Electronic address:
Objective: We sought to examine the effects of acute seizures and respiratory derangement on the cardiac electrical properties reflected on the electrocardiogram (ECG); and to analyze their potential interactions with a diagnosis of epilepsy in children.
Methods: Emergency center (EC) visits with seizure or epilepsy diagnostic codes from 1/2011-12/2013 were included if they had ECG within 24 h of EC visit. Patients were excluded if they had pre-existing cardiac conditions, ion channelopathy, or were taking specific cardiac medications.
Want 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!