Elevated temporal QT variability index in patients with chronic renal failure

2004 ◽  
Vol 107 (6) ◽  
pp. 583-588 ◽  
Author(s):  
Mats JOHANSSON ◽  
Sinsia A. GAO ◽  
Peter FRIBERG ◽  
Marita ANNERSTEDT ◽  
Göran BERGSTRÖM ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Conservative Treatment ◽  
Sudden Death ◽  
Ventricular Arrhythmia ◽  
Healthy Subjects ◽  
Increased Risk ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index

Patients with CRF (chronic renal failure) are at increased risk of cardiovascular diseases, and 60% of cardiovascular mortality in CRF is attributed to sudden death. Various abnormalities in myocardial repolarization are associated with the risk of ventricular arrhythmia. The aim of this study was to evaluate an index of temporal myocardial repolarization lability, the temporal QTVI (QT variability index), in patients with CRF. ECGs were recorded in 153 patients with CRF on haemodialysis (n=67), continuous ambulatory peritoneal dialysis (n=43) or conservative treatment (n=43) during 30 min of rest. QTVI was calculated as the logarithm of the ratio between the variances of the normalized QT and RR intervals. Age-matched healthy subjects (n=39) were examined for comparison. QTVI was increased by 47% in CRF patients compared with healthy subjects (−0.82±0.56 compared with −1.54±0.27 respectively; P<0.01). QTVI did not differ among patients on dialysis or conservative treatment, whereas QTVI was elevated further in patients with diabetes compared with non-diabetic CRF patients (−0.56±0.54 compared with −0.94±0.52 respectively; P<0.01). In a multiple linear regression analysis, diabetes and a history of coronary artery disease were the only independent predictors of QTVI in the CRF population. The present study demonstrates that elevated QTVI in patients with CRF is associated with diabetes and coronary disease. The present findings are important given that repolarization instability may predispose to ventricular arrhythmia and sudden death, events that occur frequently in CRF patients.

scholarly journals Effect of Acute Mental Stress on Heart Rate and QT Variability in Postmyocardial Infarction Patients

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Damiano Magrì ◽  
Gianfranco Piccirillo ◽  
Raffaele Quaglione ◽  
Annalaura Dell’Armi ◽  
Marilena Mitra ◽  
...  
Keyword(s):  
Acute Stress ◽  
Management Strategies ◽  
Low Frequency ◽  
Frequency Component ◽  
Postmyocardial Infarction ◽  
Increased Risk ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index

Emotionally charged events are associated with an increased risk of sudden cardiac death (SCD). In this study we assessed RR and QT variability index (QTVI) at baseline during anger recall test (AR). We calculated QTVI from a 5-min ECG recording and from a 10-beats segment around the presumed maximum sympathetic activation in thirty post-myocardial infarction patients under β-blocker therapy and 10 controls underwent. In all groups, the low-frequency component of RR and SBP increased during AR. In all recordings, the QTVI calculated on a 5-min ECG recording and the were higher in patients than in controls (P < 0.05). The QTVI during AR remained unchanged from baseline within each group. Conversely, during AR, the in controls diminished significantly (P < 0.05) from baseline whereas in patients remained unchanged. The inability to buffer an acute stress-induced increase in sympathetic activity could explain why events charged with acute stress are associated with an increased risk of ventricular arrhythmias in this setting of patients and support the role of cognitive behavior stress management strategies.

scholarly journals Transcranial direct current stimulation improves the QT variability index and autonomic cardiac control in healthy subjects older than 60 years

2016 ◽  
Vol Volume 11 ◽  
pp. 1687-1695 ◽  
Author(s):  
Gianfranco Piccirillo ◽  
Cristina Ottaviani ◽  
Claudia Fiorucci ◽  
Nicola Petrocchi ◽  
Federica Moscucci ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Healthy Subjects ◽  
Direct Current Stimulation ◽  
Cardiac Control ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index

scholarly journals Heart Rate Influence on the QT Variability Risk Factors

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1096
Author(s):  
Irena Andršová ◽  
Katerina Hnatkova ◽  
Martina Šišáková ◽  
Ondřej Toman ◽  
Peter Smetana ◽  
...  
Keyword(s):  
Heart Rate ◽  
Standard Deviation ◽  
Qt Interval ◽  
Healthy Subjects ◽  
Sequential Analysis ◽  
Rr Intervals ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index ◽  
Qt Interval Variability

QT interval variability, mostly expressed by QT variability index (QTVi), has repeatedly been used in risk diagnostics. Physiologic correlates of QT variability expressions have been little researched especially when measured in short 10-second electrocardiograms (ECGs). This study investigated different QT variability indices, including QTVi and the standard deviation of QT interval durations (SDQT) in 657,287 10-second ECGs recorded in 523 healthy subjects (259 females). The indices were related to the underlying heart rate and to the 10-second standard deviation of RR intervals (SDRR). The analyses showed that both QTVi and SDQT (as well as other QT variability indices) were highly statistically significantly (p < 0.00001) influenced by heart rate and that QTVi showed poor intra-subject reproducibility (coefficient of variance approaching 200%). Furthermore, sequential analysis of regression variance showed that SDQT was more strongly related to the underlying heart rate than to SDRR, and that QTVi was influenced by the underlying heart rate and SDRR more strongly than by SDQT (p < 0.00001 for these comparisons of regression dependency). The study concludes that instead of QTVi, simpler expressions of QT interval variability, such as SDQT, appear preferable for future applications especially if multivariable combination with the underlying heart rate is used.

Disturbed lipoprotein composition in non-dialyzed, hemodialysis, continuous ambulatory peritoneal dialysis and post-transplant patients with chronic renal failure

2006 ◽  
Vol 44 (1) ◽  
Author(s):  
Elżbieta Kimak ◽  
Andrzej Książek ◽  
Janusz Solski
Keyword(s):  
Renal Failure ◽  
Peritoneal Dialysis ◽  
Chronic Renal Failure ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Healthy Subjects ◽  
Linear Regression Analysis ◽  
Multivariate Linear Regression Analysis ◽  
Post Transplant ◽  
Transplant Patients ◽  
Lipoprotein Composition

AbstractStudies were carried out in 183 non-dialyzed, 123 hemodialysis, 81 continuous ambulatory peritoneal dialysis and 35 post-transplant patients and in 103 healthy subjects as a reference group. Lipids and apolipoprotein (apo)AI and apoB were determined using Roche kits. An anti-apoB antibody was used to separate apoB-containing apoCIII and apoE-triglyceride-rich lipoprotein (TRL) in the non-high-density lipoprotein (non-HDL) fraction from apoCIIInonB and apoEnonB in the HDL fraction in four groups of patients with chronic renal failure (CRF) and healthy subjects. Multivariate linear regression analysis was used to investigate the relationship between triglyceride (TG) or HDL-cholesterol (HDL-C) concentrations and lipoproteins. Dyslipidemia varied according to the degree of renal insufficiency, the type of dialysis and therapy regime in CRF patients. Lipoprotein disturbances were manifested by increased TG, non-HDL-C and TRL concentrations, and decreased HDL-C and apoAI concentrations, whereas post-renal transplant patients showed normalization of lipid and lipoprotein profiles, except for TG levels and total apoCIII and apoCIIInonB. The present study indicates that CRF patients have disturbed lipoprotein composition, and that hypertriglyceridemia and low HDL-C concentrations in these patients are multifactorial, being secondary to disturbed lipoproteins. The method using anti-apoB antibodies to separate apoB-containing lipoproteins in the non-HDL fraction from non-apoB-containing lipoproteins in HDL can be used in the diagnosis and treatment of patients with progression of renal failure or atherosclerosis. The variability of TG and HDL-C concentrations depends on the variability of TRL and cholesterol-rich lipoprotein concentrations, but the decreases in TG and increases in HDL-C concentrations are caused by apoAI concentration variability. These relationships, however, need to be confirmed in further studies.

Calcium phosphate product level as a predictor for arteriovenous fistula re-operations in patients with chronic renal failure

Vascular ◽  
2018 ◽  
Vol 27 (3) ◽  
pp. 284-290 ◽  
Author(s):  
Mehmet Erin Tüysüz ◽  
Mehmet Dedemoğlu
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Calcium Phosphate ◽  
Arteriovenous Fistula ◽  
Product Level ◽  
Increased Risk ◽  
High Calcium ◽  
Phosphate Product ◽  
Group 2 ◽  
Group 1

Objectives There is an increased calcium phosphate product level causing the formation of calcification in the arterial wall and thus decreased quality of fistula in patients with chronic renal failure. The purpose of our study is to verify the relationship between arteriovenous fistula re-operation and high calcium phosphate product level. Methods Seventy-nine consecutive patients with chronic renal failure between April 2016 and February 2018 were included in the study. Patients having calcium phosphate product level ≥50 mg2/dl2 were defined as group 1, whereas those having <50 mg2/dl2 were defined as group 2. Primary outcome of interest was the need for re-operation during the follow-up and to determine the risk factors for re-operation. To determine independent predictors for re-operation, multivariate logistic regression model was used. Results The rates of redo and tredo operation were significantly higher in group 1 compared to group 2 ( p = 0.01 and 0.04). In multivariate analysis, phosphate (OR: 1.84, 95% CI: 1.00–3.40, p = 0.05) and triglyceride (OR: 1.01, 95% CI: 1.00–1.02, p = 0.04) levels for redo operation and calcium phosphate product level (OR: 1.11, 95% CI: 1.01–1.22, p = 0.03) for tredo operation were found to be independent predictors. Conclusions High calcium phosphate product level leads to increased risk of arteriovenous fistula re-operation by causing arterial stiffness in this patient group. Additionally, these re-operations place additional burden on morbidity and cost efficacy. Thus, we recommend keeping the calcium phosphate product level at the optimal level in these patients to avoid both the risk of arteriovenous fistula re-operation and the other cardiovascular problems.

scholarly journals Maturation of the QT Variability Index is Impaired in Preterm Infants

2018 ◽  
Vol 39 (5) ◽  
pp. 902-905 ◽  
Author(s):  
Arisa Kojima ◽  
Tadayoshi Hata ◽  
Tsuneaki Sadanaga ◽  
Yuri Mizutani ◽  
Hidetoshi Uchida ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index

Increased QT variability index as a marker for a cardiac autonomic dysregulation in schizophrenia

2013 ◽  
Author(s):  
Hariton Costin ◽  
Steffen Schulz ◽  
Karl-Jurgen Bar ◽  
Ioana Alexa ◽  
Felix Adochiei ◽  
...  
Keyword(s):  
Autonomic Dysregulation ◽  
Qt Variability Index ◽  
Qt Variability ◽  
Variability Index
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