Objectives: To introduce a nomogram of the normal QT interval at various heart rates measured from 24 hour Holter ECG recordings in healthy subjects with respect to age and sex and to use the nomogram to characterise dynamic changes in QT interval in patients with idiopathic ventricular fibrillation (IVF) and the long QT syndrome (LQT).
Methods: The study group consisted of 422 subjects: 249 healthy men ranging in age from 21-88 years (mean (SD) 47 (20) years) and 173 healthy women ranging in age from 21-85 years (47 (19) years). In addition, seven men with IVF ranging in age from 33-53 years (43 (9) years) and five women with LQT ranging in age from 20-55 years (37 (14) years) were studied. For each subject, QT interval and heart rate were determined automatically from 24 hour Holter ECG digital data-namely, QT interval was measured from signal averaged ECG waves obtained by averaging consecutive sinus beats during each 15 second period over 24 hours. Data were grouped and averaged at an interval of 5 beats/min for heart rates ranging from 46-120 beats/min.
Results: In healthy subjects aged < 50 years and > or = 50 years QT intervals were longer in women than in men. QT intervals were longer in both men and women aged > or = 50 years than in ages < 50 years. From these findings a nomogram of QT interval at varying heart rates adjusted for age (younger group aged < 50 years or older group aged > or = 50 years) and sex was determined. In patients with IVF, QT intervals were significantly shorter at slower heart rates than normal values obtained from the nomogram. In patients with LQT, QT intervals were significantly longer at both faster and slower heart rates than normal values.
Conclusions: The nomogram of QT interval at varying heart rates adjusted for sex and age could be used to assess dynamic changes of QT interval of various pathological conditions. For example, patients with IVF had shorter QT interval at slower heart rates, a finding suggestive of arrhythmogenicity of this specific syndrome at night. Patients with LQT had prolonged QT interval at specific heart rate ranges depending on their genotype.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860750 | PMC |
| http://dx.doi.org/10.1136/hrt.2004.059071 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nationwide trends and outcomes of percutaneous coronary intervention for stable ischemic heart disease in end-stage kidney disease: a longitudinal study.
Ann Transl Med
December 2024
Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, USA.
Background: Patients with end-stage kidney disease (ESKD) are at high risk for coronary artery disease. We investigate the trends and outcomes of percutaneous coronary intervention (PCI) for stable ischemic heart disease (SIHD) in patients with ESKD.
Methods: We utilized the United States Renal Data System [2010-2018] to include adult patients with ESKD on dialysis for at least 3 months who underwent PCI for SIHD.
30-Day and 1-Year Acute Myocardial Infarction Outcomes in Côte d'Ivoire: The REACTIV Study.
JACC Adv
December 2024
Interventional Cardiology Department, Abidjan Heart Institute, Abidjan, Côte d'Ivoire.
Background: Whereas the increasing burden of acute myocardial infarction (MI) has been reported in sub-Saharan Africa, little is known about short- and long-term prognosis following acute MI.
Objectives: The purpose of this study was to assess in-hospital, 30-day, and 1-year all-cause mortality and adverse outcomes in patients with MI hospitalized at a cardiac center in Côte d'Ivoire.
Methods: This prospective cohort study used data from the REgistre des syndromes coronariens Aigus de CôTe d'IVoire (REACTIV).
Background: Cardiovascular diseases are the primary cause of nonobstetric morbidity and mortality in pregnant women worldwide. Pakistan's high maternal and neonatal mortality rates underscore the need for effective screening protocols to detect cardiovascular diseases during pregnancy.
Objectives: The objective of this study was to assess the prevalence and factors associated with structural heart disease among pregnant women without active cardiorespiratory symptoms (no symptoms or symptoms attributed to pregnancy) attending routine antenatal appointments.
Valvular Heart Disease-Related Mortality Between Middle- and High-Income Countries During 2000 to 2019.
JACC Adv
December 2024
Division of Cardiac Surgery, St. Michael's Hospital of Unity Health Toronto, Toronto, Ontario, Canada.
Background: Valvular heart disease (VHD) management has evolved rapidly in recent decades, but disparities in health care access persist among countries with varying socioeconomic backgrounds.
Objectives: The purpose of this study was to investigate global mortality trends from VHD and assess the difference between middle- and high-income countries.
Methods: We obtained mortality data from the World Health Organization Mortality Database for VHD and its subgroups (rheumatic valvular disease [RVD], infective endocarditis [IE], aortic stenosis [AS], and mitral regurgitation [MR]) from 2000 to 2019.
Electrical Heterogeneity in Hispanic Background Subpopulations: The HCHS/SOL.
JACC Adv
December 2024
Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, New York, USA.
Background: The Hispanic/Latino population is not uniform. Prevalence and clinical outcomes of cardiac arrhythmias in ethnic background subgroups are variable, but the reasons for differences are unclear. Vectorcardiographic Global Electrical Heterogeneity (GEH) has been shown to be associated with adverse cardiovascular outcomes.
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!