scholarly journals QT Interval Variability Index and QT Interval Duration in Different Sleep Stages: Analysis of Polysomnographic Recordings in Nonapneic Male Patients

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Moonika Viigimae ◽  
Deniss Karai ◽  
Peeter Pirn ◽  
Kristjan Pilt ◽  
Kalju Meigas ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Qt Interval ◽  
Sleep Stages ◽  
Qtc Interval ◽  
Interval Duration ◽  
Obstructive Sleep ◽  
Male Patients ◽  
Clinically Significant ◽  
Qt Interval Duration ◽  
Qt Interval Variability

The aim of the study was to determine whether different sleep stages, especially REM sleep, affect QT interval duration and variability in male patients without obstructive sleep apnea (OSA). Polysomnographic recordings of 30 patients were analyzed. Beat-to-beat QT interval variability was calculated using QTV index (QTVI) formula. For QTc interval calculation, in addition to Bazett’s formula, linear and parabolic heart rate correction formulas with two separateαvalues were used. QTVI and QTc values were calculated as means of 2 awake, 3 NREM, and 3 REM sleep episodes; the duration of each episode was 300 sec. Mean QTVI values were not statistically different between sleep stages. Therefore, elevated QTVI values found in patients with OSA cannot be interpreted as physiological sympathetic impact during REM sleep and should be considered as a risk factor for potentially life-threatening ventricular arrhythmias. The absence of difference of the mean QTc interval values between NREM and REM stages seems to confirm our conclusion that sympathetic surges during REM stage do not induce repolarization variability. In patients without notable structural and electrical remodeling of myocardium, physiological elevation in sympathetic activity during REM sleep remains subthreshold concerning clinically significant increase of myocardial electrical instability.

scholarly journals Normal and abnormal QT interval duration and its changes in preadolescents and adolescents practicing sport

EP Europace ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1566-1574 ◽  
Author(s):  
Flavio D’Ascenzi ◽  
Francesca Anselmi ◽  
Francesca Graziano ◽  
Beatrice Berti ◽  
Andrea Franchini ◽  
...  
Keyword(s):  
Qt Interval ◽  
Qtc Interval ◽  
Interval Duration ◽  
Prospective Longitudinal Study ◽  
Repolarization Phase ◽  
Life Threatening ◽  
Qt Interval Duration ◽  
Electrocardiogram Ecg ◽  
Prospective Longitudinal

Abstract Aims Twelve-lead electrocardiogram (ECG) is an established tool in the evaluation of athletes, providing information about life-threatening cardiovascular diseases, such as long QT syndrome. However, the interpretation of ECG is sometimes challenging in children, particularly for the repolarization phase. The aim of this prospective, longitudinal study was to determinate the distribution of QT interval in children practicing sport and to evaluate changes in QT duration overtime. Methods and results A population of 1473 preadolescents practising sport (12.0 ± 1.8 years, 7–15 years) was analysed. Each athlete was evaluated at baseline, mid-term, and end of the study (mean follow-up: 3 ± 1 years). QT interval was corrected with Bazett (B) and Fridericia (F) formulae. At baseline QT interval corrected with the Bazett formula (QTcB) was 412 ± 25 ms and QT interval corrected with the Fridericia formula (QTcF) 387 ± 21 ms, with no changes during follow-up. Ten children (0.68%) had an abnormal QTc. In those with QTcB and QTcF ≥480 ms, QTc duration persisted abnormal during the follow-up and they were disqualified. Conversely, children with 460 ms < (QTcB) <480 ms had a normal QTc interval at the end of the study. These children had also a normal QTcF. Mean difference in the calculation of QT between the two formulae was 25 ± 11 ms (P < 0.0001). For resting heart rate (HR) ≥82 b.p.m., QTcF was independent from HR contrary to QTcB. Conclusion Normal QTc interval does not change over time in preadolescents. A minority of them has a QTc ≥480 ms; in these subjects, QTc interval remains prolonged. The use of Bazett and Fridericia correction formulae is not interchangeable and the Fridericia correction should be preferred in preadolescents with a resting HR ≥82 b.p.m.

High Prevalence of Prolonged QT Interval Duration in Male Patients with Cushing's Disease

2011 ◽  
Vol 119 (04) ◽  
pp. 221-224 ◽  
Author(s):  
F. Pecori Giraldi ◽  
P. M. Toja ◽  
G. Michailidis ◽  
A. Metinidou ◽  
M. De Martin ◽  
...  
Keyword(s):  
Cushing’S Disease ◽  
Qt Interval ◽  
Cushing's Disease ◽  
Interval Duration ◽  
High Prevalence ◽  
Prolonged Qt Interval ◽  
Male Patients ◽  
Prolonged Qt ◽  
Qt Interval Duration

scholarly journals Coffee, Alcohol, Smoking, Physical Activity and QT Interval Duration: Results from the Third National Health and Nutrition Examination Survey

PLoS ONE ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. e17584 ◽  
Author(s):  
Yiyi Zhang ◽  
Wendy S. Post ◽  
Darshan Dalal ◽  
Elena Blasco-Colmenares ◽  
Gordon F. Tomaselli ◽  
...  
Keyword(s):  
Physical Activity ◽  
National Health ◽  
Qt Interval ◽  
Nutrition Examination Survey ◽  
Interval Duration ◽  
The Third ◽  
Health And Nutrition ◽  
Qt Interval Duration

scholarly journals Complex Influence of Gonadotropins and Sex Steroid Hormones on QT Interval Duration

2016 ◽  
Vol 101 (7) ◽  
pp. 2776-2784 ◽  
Author(s):  
Guillaume Abehsira ◽  
Anne Bachelot ◽  
Fabio Badilini ◽  
Laurence Koehl ◽  
Martine Lebot ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Qt Interval ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Interval Duration ◽  
Qt Interval Duration ◽  
Complex Influence

Abstract 2924: Association of NOS1AP Genetic Variants with QT Interval Duration in Families from the Diabetes Heart Study

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Allison B Lehtinen ◽  
Christopher Newton-Cheh ◽  
Julie T Ziegler ◽  
Carl D Langefeld ◽  
Barry I Freedman ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Qt Interval ◽  
Genetic Model ◽  
Additive Model ◽  
Adaptor Protein ◽  
European Ancestry ◽  
Nucleotide Polymorphisms ◽  
Interval Duration ◽  
Common Genetic Variants ◽  
Qt Interval Duration

Background: Prolongation of the electrocardiographic QT interval is a risk factor for sudden cardiac death (SCD) in unselected samples as well as in post-myocardial infarction patients or those with diabetes. Common genetic variants in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene have been reported to be associated with QT interval duration in individuals of European ancestry. We sought to replicate the association of NOS1AP variants with QT interval duration in pedigrees enriched for type 2 diabetes mellitus (T2DM). Methods and Results: Two single nucleotide polymorphisms (SNPs) in the NOS1AP gene, rs10494366 and rs10918594, were genotyped in a collection of 937 European Americans (EAs) and 177 African Americans (AAs) in 450 pedigrees containing at least two siblings with T2DM. An additive genetic model was tested for each SNP in ancestry-specific analyses using SOLAR in the total sample and in the diabetic subset (EA n=778, AA n=159), with and without exclusion of QT-altering medications. In the EA individuals, rs10494366 minor allele homozygotes had an 8.9 msec longer mean QT interval compared to major homozygotes (additive model p=4.4x10 -3 ); rs10918594 minor homozygotes had a 12.9 msec longer mean QT interval compared to major homozygotes (p=9.9x10 -5 ). Excluding users of QT-altering medications in the diabetic-only EA sample (n=514) strengthened the association despite the reduction in sample size (20.6 msec difference, p=2.0x10 -5 ; 23.4 msec difference, p=8.9x10 -7 , respectively). No association between the NOS1AP SNPs and QT interval duration was observed in the limited number of AA individuals examined. Conclusions: Two NOS1AP SNPs are strongly associated with QT interval duration in a predominately diabetic EA sample. Stronger effects of NOS1AP variants in diabetic individuals compared to previously reported unselected samples suggest that this patient subset may be particularly susceptible to genetic variants that influence myocardial depolarization and repolarization as manifest in the QT interval.

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