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Dive into the research topics where Bülent Koca is active.

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Featured researches published by Bülent Koca.


Journal of Cardiology | 2013

Heart rate variability in patients with atrial septal defect and healthy children

Süleyman Bakari; Bülent Koca; Funda Öztunç; Mahmut Abuhandan

OBJECTIVE Heart rate variability (HRV) measures are altered in various cardiac and non-cardiac situations in children. The autonomic nervous system is assumed to have a role in the pathophysiology of atrial septal defect (ASD). In this study, we evaluated the autonomic system by measuring HRV in children with ASD. METHODS Twenty-eight patients with ASD and 32 healthy children (mean ages: 6.6±2.1 years and 6.4±2.2 years, respectively) were enrolled in the study. Twenty-four-hour ambulatory electrocardiographic recordings were obtained and the seven time-domain (SDNN, SDANN, rMSSD, SD, SDNN index, PNN50, and mean RR) and four frequency-domain (VLF, LF, HF, and LF/HF ratio) indices of HRV were analyzed. RESULTS A significant decrease in calculated HRV variables was observed in children with ASD as compared to controls. The HRV alteration was found in both time-domain and frequency-domain parameters. CONCLUSIONS Our results indicate that HRV is decreased in children with ASD, which implies parasympathetic withdrawal and sympathetic predominance.


Cardiology in The Young | 2014

Evaluation of right ventricular function in patients with tetralogy of Fallot using the myocardial performance index and isovolumic acceleration: a comparison with cardiac magnetic resonance imaging.

Bülent Koca; Funda Öztunç; Ayşe Güler Eroğlu; Selman Gökalp; Memduh Dursun; Ravza Yilmaz

BACKGROUND Assessment of right ventricular function is a key point in the follow-up of operated patients with tetralogy of Fallot. Cardiac magnetic resonance assessment of right ventricular function is considered the gold standard. However, this technique is expensive, has limited availability, and requires significant expertise to acquire and interpret the images. Myocardial performance index and isovolumic acceleration have recently been studied for the assessment of right ventricular function and are shown to be simple yet powerful tools for assessing patients with right ventricular dysfunction of various origins. METHODS In this study, the integrity of myocardial performance index and isovolumic acceleration obtained by tissue Doppler imaging echocardiography to quantify right ventricular function was assessed in 31 patients operated for tetralogy of Fallot. Myocardial performance index and isovolumic acceleration measurements were compared with the parameters derived by cardiac magnetic resonance imaging. RESULTS In this study, a significant correlation has not been detected between cardiac magnetic resonance-originated right ventricular ejection fraction, pulmonary regurgitation fraction and myocardial performance index, isovolumic acceleration obtained by tissue Doppler imaging echocardiography from the lateral tricuspid annulus of the right ventricle. CONCLUSION We have concluded that when evaluated separately, myocardial performance index and isovolumic acceleration obtained from tissue Doppler imaging echocardiography can be used in the long-term follow-up of patients who have been operated for tetralogy of Fallot, but that they do not show correlation with cardiac magnetic resonance-originated right ventricle ejection fraction and pulmonary regurgitation fraction.


Epilepsy Research | 2014

An evaluation of serum paraoxonase together with arylesterase activities and oxidative stress in children with intractable epilepsy: A cross-sectional study

Mustafa Calik; Elif Oguz; Suna Sarikaya; Özcan Kocatürk; Bülent Koca; Hatice Eke Gungor; Nurten Aksoy; T.K. Yoldas; Akin Iscan

Epilepsy is the most common chronic neurological illness in childhood and adolescence. The aim of this study was to investigate paraoxonase and arylesterase activities along with oxidative status parameters in children with intractable epilepsy. The study comprised 42 subjects with intractable epilepsy and a control group of 35 healthy subjects. Serum paraoxonase and arylesterase activities, and lipid hydroperoxide levels were determined. All paraoxonase and arylesterase activities were significantly lower in the intractable epilepsy subjects than in the controls (P<0.001), whereas lipid hydroperoxide levels were significantly higher (P<0.05). In conclusion, paraoxonase and arylesterase activities were decreased and the lipid hydroperoxide level was increased in patients with intractable epilepsy. These results showed that intractable epilepsy subjects may be more prone to the development of atherosclerosis.


European Journal of Radiology | 2017

Brain metabolite alterations in Eisenmenger syndrome: Evaluation with MR proton spectroscopy☆

Dilek Şen Dokumacı; Ferit Doğan; Ali Yıldırım; Fatıma Nurefşan Boyacı; Erol Bozdogan; Bülent Koca

OBJECTIVE Eisenmenger syndrome (ES) is a life-threatening disease characterized by pulmonary hypertension and cyanosis in patients with congenital heart diseases. The aim of this study was to determine the brain metabolite changes in Eisenmenger syndrome compared with a control group using MR proton spectroscopy. METHODS AND MATERIALS The study included 10 children (3 male, 7 female) with congenital heart diseases and a diagnosis of Eisenmenger syndrome. The control group consisted of 10 healthy volunteer children. All were examined with a 1.5T MRI scanner and single voxel spectroscopy was performed to obtain spectra from three different regions; left frontal subcortical white matter, left lentiform nucleus and left thalamus. Peak integral values obtained from the spectra were used as quantitative data. RESULTS The ages of the children with ES were between 5 and 16 years, and between 5 and 15 years in the control group. Periventricular white matter hyperintensities were observed in 3 patients. On MR spectroscopy study, significantly lower levels of Choline metabolite (Cho) were detected in the frontal subcortical region and thalamus regions of the patients compared with the control group. There was no statistically significant difference between the levels of other metabolites (NAA, Cr, mI and Glx). In the lentiform nucleus, although the average value of Cho in ES patients was lower than that of the control group, it was not statistically significant. CONCLUSION Cho metabolite was determined to have an important role in brain metabolism in Eisenmenger syndrome patients. Oral Cho treatment may help to extend survival.


Epilepsy & Behavior | 2018

The measurement of both carotid intima-media thickness and epicardial adipose tissue thickness in children with epilepsy receiving antiepileptic drug therapy

Mustafa Calik; Hatice Yıldız Ozkan; Ozlem Ethemoglu; Bülent Koca; Halil Kazanasmaz; Nurettin Karacan; Dilek Sen Dokumaci

OBJECTIVE The aim of this study was to evaluate the carotid intima-media thickness together with the thickness of the epicardial adipose tissue in patients receiving antiepileptic drug therapy and to investigate the presence of increased cardiovascular risk in these patients. METHODS The study included a total of 52 patients comprising 32 males and 20 females who were diagnosed as having epilepsy and who were using one or more antiepileptic drugs. The control group consisted of 34 healthy individuals comprising 16 males and 18 females. The individuals selected for the study group were requested to go to the hospital after overnight fasting. After blood sampling for serum lipid value, the carotid intima-media thickness was measured with high resolution B-mode ultrasonography and epicardial adipose tissue thickness with echocardiography in the patients and the control group subjects. RESULTS The carotid intima-media thickness was determined as 0.47 ± 0.05 mm in the patient group and 0.44 ± 0.04 mm in the control group (p = 0.028). The carotid intima-media thickness was measured as 0.45 ± 0.05 mm in patients with epilepsy taking monotherapy and 0.49 ± 0.04 mm in those taking polytherapy (p = 0.003). The epicardial adipose tissue thickness was determined as 3.42 ± 0.09 mm in the patient group and 1.72 ± 0.90 mm in the control group (p = 0.000). The epicardial adipose tissue thickness was measured as 3.16 ± 0.87 mm in patients with epilepsy taking monotherapy and 3.77 ± 0.83 mm in those taking polytherapy (p = 0.041). CONCLUSIONS It was determined that carotid intima-media thickness and epicardial adipose tissue thickness were significantly high in children with epilepsy taking long-term antiepileptic drugs. These results demonstrate that these patients could be at increased risk of the development of cardiovascular complications. There is a need for more extensive studies on this subject.


Clinical Rheumatology | 2015

Use of tissue Doppler and its comparison with other pulse Doppler echocardiography in the evaluation of diastolic functions in patients with active juvenile idiopathic arthritis

Bülent Koca; Tevfik Demir; Ozgur Kasapcopur


Turkish Journal Of Neurology | 2016

P Wave Dispersion in Children with Breath-holding Spells

Tahsin Gider; Bülent Koca; Mustafa Calik; Ali Yıldırım; Savaş Demirpençe


Archive | 2016

P Wave Dispersion in Children with Breath-holding Spells Soluk-tutma Nöbetli Çocuklarda P Dalga Dispersiyonu

Tahsin Gider; Bülent Koca


British Journal of Radiology | 2016

Brain diffusion changes in Eisenmenger syndrome

Ferit Doğan; Dilek Sen Dokumaci; Ali Yıldırım; Erol Bozdogan; Fatıma Nurefşan Boyacı; Bülent Koca; Ekrem Karakas


Pediatric Cardiology | 2014

Relationships between Left Heart Chamber Dilatation on Echocardiography and Left-to-Right Ventricle Shunting Quantified by Cardiac Catheterization in Children with Ventricular Septal Defects

Selman Gokalp; Ayşe Güler Eroğlu; Levent Saltik; Bülent Koca

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