Factors Associated With a Prolonged Qt Interval in Hypertensive Patients

Mozoş, Ioana; Patrascu, R.; Serban, C.; Pacurari, A.; Tudor, Aura; Susan, L.

doi:10.1097/00004872-201106001-01490

Cited by 4 publications

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“…Anemia was associated with prolonged QT intervals in hypertensive [106] and end stage renal disease patients [107], as well. Associations between the QT interval and serum ferritin level [108] and anisocytosis [106], respectively, were mentioned. Scheller et al [109] reported a gradual prolongation of the QT and QTc interval in normovolemic anemia.…”

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 85%

“…Several electrocardiographic changes were previously mentioned in patients with anemia, including prolonged QT intervals, ST segment depression, inverted T waves, increased R amplitude after stress test [105]. Anemia was associated with prolonged QT intervals in hypertensive [106] and end stage renal disease patients [107], as well. Associations between the QT interval and serum ferritin level [108] and anisocytosis [106], respectively, were mentioned.…”

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 89%

“…Scheller et al [109] reported a gradual prolongation of the QT and QTc interval in normovolemic anemia. Anemia may increase cardiac output and heart rate, may lead to eccentric left ventricular hypertrophy, activation of the sympathetic nervous system, stimulation of the renin angiotensin aldosterone system, and is closely associated with chronic inflammation and increased oxidative stress [106,110]. Tissue hypoxia and changes in blood flow patterns due to low hemoglobin may play an atherogenic role [110].…”

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

“…Tissue hypoxia and changes in blood flow patterns due to low hemoglobin may play an atherogenic role [110]. The pathophysiological link between anemia and prolonged QT intervals and ventricular arrhythmia risk is, probably, hypoxia and decreased myocardial oxygen supply [106].…”

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

“…Left ventricular systolic and diastolic dysfunction, increased QTc intervals and QT dispersions and late ventricular potentials were found in patients with beta-thalassemia, a genetic cause of anemia, due to reduced synthesis of beta-globin chains [112,113]. Several mechanisms explain increased sudden cardiac death in patients with thalassemia, including iron overload thalassemic cardiomyopathy, with patchy cardiac iron depostition (due to intensive blood transfusions), changes in calcium homeostasis, elevated prostaglandin E2 to prostacyclin ratio, increased interleukin 1 level and lipid peroxidation [106,113,114].…”

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

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Ventricular Arrhythmia Risk in Noncardiac Diseases

Mozoş¹

2014

Cardiac Arrhythmias - Mechanisms, Pathophysiology, and Treatment

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diseases, to mention the main methods used to assess arrhythmia risk, as well as to elucidate their relation to long-term outcome. Dyslipidemia, obesity, diabetes mellitus, liver, hematologic, neurologic and psychiatric disorders, are discussed. Dyslipidaemia and ventricular arrhythmia riskElevated LDL cholesterol was associated with all manifestations of coronary artery disease including sudden cardiac death [7]. Hypercholesterolemia is not only atherogenic, but is also associated with autonomic imbalance, alteration of the contractile properties of the myocardium, increased oxidative stress and ventricular electrophysiological remodeling [8,9]. Myocardial electrical remodeling due to hypercholesterolemia caused prolonged action potential durations, longer QTc (heart rate corrected QT interval durations), conduction slowing and increased repolarization dispersion [9,10].Several clinical and autopsy studies demonstrated an association between elevated cholesterol levels and sudden cardiac death [11,12]. Gualdiero et al. reported a positive correlation between cholesterol level, QT dispersion and premature ventricular contractions in patients with isolated hypercholesterolemia, and normalization of serum cholesterol and QT dispersion and improvement of ventricular ectopic activity, with simvastatin [13]. Szabo et al. found significant correlations of QT interval duration and QT dispersion with total and LDL cholesterol, triglycerides and apoplipoprotein B, respectively, in patients with type IIb hyperlipoproteinemia, without myocardial ischemia, suggesting a direct effect of hyperlipidemia on ventricular repolarization [14]. LDL increases the cholesterol to phospholipid ratio in the cell membrane, enhancing membrane rigidity and impairing functionality of the ion channels and ventricular repolarization [14,15]. Ventricular repolarization is reflected by the QT interval on the ECG, which is regulated mainly by potassium channels. On the other hand, type II hyperlipoproteinemia is characterized by accelerated atherosclerosis, related to small dense LDL synthesis.It was also hypothesized that hypercholesterolemia causes repolarization abnormalities, probably, by beta or IK channel phosphorylation mediated mechanisms [9]. Hypercholesterolemia causes also endothelial dysfunction, with impaired microvascular vasodilatation, facilitating vasoconstriction, and electrical heterogeneity and extrasystolic activity [13]. The increase in the QT interval duration in cholesterol fed rabbits was lesser if L-Arginine was supplemented, suggesting a beneficial role of L-Arginine (a nitric acid precusror) in hypercholesterolemia induced repolarization characteristics [9]. L-Arginine increases endogenous nitric oxide, which may activate ATP dependent K channels, shortening the action potential [9].Late ventricular potentials were detected in patients with high and moderately elevated serum cholesterol [5,16].Cardiac Arrhythmias -Mechanisms, Pathophysiology, and Treatment 90

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Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 85%

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 89%

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

Section: Hematologic Diseases and Ventricular Arrhythmia Riskmentioning

confidence: 99%

See 3 more Smart Citations

Ventricular Arrhythmia Risk in Noncardiac Diseases

Mozoş¹

2014

Cardiac Arrhythmias - Mechanisms, Pathophysiology, and Treatment

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Does Iron Deficiency Affect the Heart in Children?

Demir¹,

Kayalı²,

Gökçebay³

2021

Journal of Pediatric Hematology/Oncology

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Introduction: It is well known that serum iron parameters are closely related to cardiovascular health. Iron deficiency may lead to significant cardiac problems, such as atrioventricular conduction abnormalities, and systolic and/or diastolic dysfunction. Studies related to the effect of iron deficiency on cardiac functions are limited in children. Therefore, the aim of this study was to evaluate the effect of low iron stores on cardiac repolarization parameters which are used to predict arrhythmia and cardiac functions.Materials and Methods: Onehundred thirty-five children 2 to 18 years of age without structural heart disease who were referred to the Pediatric Cardiology Department for various reasons such as chest pain, heart murmur, or evaluation before sports participation were evaluated prospectively. The cases were separated into 3 groups according to ferritin levels (group 1: ferritin <15 ng/mL [n = 48], group 2: ferritin 15 to 25 ng/mL [n = 51], and group 3: ferritin > 25 ng/mL [n = 36]). Evaluations were made with detailed 12-lead surface electrocardiography (ECG) and transthoracic echocardiogram. Cardiac repolarization parameters were measured from surface ECG and systolic functions, left ventricular wall diameters were evaluated from transthoracic echocardiogram.Results: Eighty-four (62.2%) girls and 51 (37.8%) boys are included in the study. The average age of the groups was similar. In children with low ferritin levels (group 1); Pw, Pw max, and Pw dis; QT, QTc, and QTc dis; Tp-Te, Tp-Te dis, Tp-Te/QT, and Tp-Te/QTc were significantly longer compared with the group 3 (P < 0.05). There was a negative correlation between ferritin level and Pw, P max, and Pw dis; QT, QT dis, QTc, and QTc dis; Tp-Te, Tp-Te dis, Tp-Te/QT, and Tp-Te/QTc (P < 0.05). No correlation was found between ferritin level and Pw min. There was no difference between the groups in respect of ejection phase indices, heart wall measurements, and end-diastolic diameter measurements. Conclusion:Iron deficiency may be related to the tendency of arrhythmias in children without structural heart disease. Therefore, careful evaluation of ECG parameters of healthy children with low iron stores, and follow up with intermittent monitoring is highly important.

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Disturbances in cardiac electrical Systole and its relationship with sudden death

2015

JCCR

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Factors Associated With a Prolonged Qt Interval in Hypertensive Patients

Cited by 4 publications

References 0 publications

Ventricular Arrhythmia Risk in Noncardiac Diseases

Ventricular Arrhythmia Risk in Noncardiac Diseases

Does Iron Deficiency Affect the Heart in Children?

Disturbances in cardiac electrical Systole and its relationship with sudden death

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